Abdominal — NAEOTOM Connect https://connect.siemens-healthineers.com/ja/ Fri, 23 Oct 2026 15:10:08 +0000 ja Abdominal — NAEOTOM Connect (2022) Lennartz | Virtual unenhanced images show limitations for adrenal adenoma characterization https://connect.siemens-healthineers.com/ja/discussion/486/2022-lennartz-virtual-unenhanced-images-show-limitations-for-adrenal-adenoma-characterization Thu, 27 Aug 2026 17:27:06 +0000 Publication protocols Daniel Stromer 486@/ja/discussions

PCCT-derived virtual unenhanced (VUE) images showed no significant difference in mean attenuation compared with true unenhanced (TUE) images for adrenal adenomas (9.2 ± 8.6 HU vs 7.3 ± 8.4 HU; P = .07).


Despite similar mean values, individual VUE measurements showed both over- and underestimation, resulting in 10 of 36 adrenal adenomas being misclassified when the conventional 10-HU threshold was applied to VUE images.


Material decomposition was tissue dependent: VUE underestimated attenuation in muscle and the portal vein while overestimating fat attenuation, indicating that further technical optimization is required before VUE can reliably replace TUE imaging for adrenal adenoma assessment.

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Figure 2. Case examples for photon-counting detector CT–derived images in adrenal adenoma. Left column: Axial true unenhanced (TUE) images. Middle column: Virtual unenhanced (VUE) images. Right column: Corresponding contrast-enhanced portal venous phase images. (A–C) Images in a 79-year-old woman with lipid-rich adenoma of the left adrenal gland. VUE images led to overestimation of adrenal gland attenuation, which hampered correct classification as lipid-rich adenoma using the 10-HU threshold. (D–F) Images in a 65-year-old woman with lipid-rich adenoma in the left adrenal gland. Classification based on VUE images was in concordance with classification based on TUE images, albeit with a slight overestimation of attenuation on VUE images. (G–I) Images in a 79-year-old woman with lipid-poor adenoma in the left adrenal gland show high contrast material enhancement. VUE images led to 12-HU underestimation when compared with TUE attenuation, which would still result in the correct classification.

Protocol

Detail

Value

Scanner

NAEOTOM Alpha

Scan area

Abdomen / adrenal glands

Scan mode

True unenhanced + portal venous phase

Acquisition mode

QunatumPlus

Tube voltage [kV]

120

Effective mAs [mAs]

Automated exposure control

IQ level

170

Pitch

0.8

Rotation time [s]

0.25–0.5

Detector slice collimation

144 × 0.4 mm

Slice thickness

2 mm

Matrix

512 × 512

Iterative reconstruction

QIR 4

Reconstruction

Axial

Material decomposition

VUE reconstructed from portal venous phase

Contrast agent

Accupaque 300

Contrast phase

Portal venous

Key Results

Parameter

Main finding

Study population

29 patients, 36 adrenal adenomas

VUE vs TUE attenuation

9.2 ± 8.6 vs 7.3 ± 8.4 HU; P = .07

10-HU classification

10/36 adenomas misclassified using VUE

Lipid-rich adenomas

23/36

Lipid-poor adenomas

13/36

Tissue dependence

VUE underestimated muscle/portal vein and overestimated fat attenuation

Clinical implication

VUE cannot yet reliably substitute for TUE when applying the conventional 10-HU threshold

Source: Lennartz S, Schoenbeck D, Kröger JR, Borggrefe J, Niehoff JH. Photon-counting CT Material Decomposition: Initial Experience in Assessing Adrenal Adenoma. Radiology. 2023;306(1):202–204. doi:10.1148/radiol.220919.

]]> (2025) Zhang | UHR PCCT versus 40-keV VMI for abdominal artery visualization https://connect.siemens-healthineers.com/ja/discussion/497/2025-zhang-uhr-pcct-versus-40-kev-vmi-for-abdominal-artery-visualization Fri, 28 Aug 2026 10:20:38 +0000 Publication protocols Daniel Stromer 497@/ja/discussions

This prospective study compared 0.2-mm ultra-high-resolution (UHR) PCCT with 1-mm standard-resolution 40-keV VMI for abdominal CTA in 94 participants, equally divided between full-dose and low-dose protocols. Standard-resolution 40-keV VMI provided significantly higher SNR and CNR than all UHR reconstructions.


UHR reconstruction nevertheless improved vessel sharpness, particularly with the sharper Bv56 and Bv60 kernels, but the associated increase in image noise reduced overall image quality. The smoother Bv48 UHR reconstruction provided the best balance, with overall quality comparable to standard-resolution 40-keV VMI.


Importantly, abdominal artery visibility was broadly comparable across full- and low-dose reconstructions. The authors therefore favor 1-mm low-dose 40-keV VMI for routine abdominal CTA, while 0.2-mm UHR Bv48 may be valuable when very thin slices and visualization of distal vascular segments are specifically required.

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Figure 5. Representative example of two participants who both underwent full-dose scan. A A 71-year man with a BMI of 19.7 kg/m2 underwent abdominal CTA using a FD protocol with CTDIvol, DLP, SSDE, and effective dose of 6.23 mGy, 212.0 mGy·cm, 9.06 mGy, and 3.18 mSv, respectively. The data were reconstructed into FD_UHR_Bv48, FD_UHR_Bv56, FD_UHR_Bv60, FD_SR_Bv40 images, respectively. The UHR images have higher image noise, but better vessel sharpness. The overall quality of FD_UHR_Bv48, and FD_SR_Bv40 images are comparable. The FD_UHR_Bv56 and FD_UHR_Bv60 images presented better vessel sharpness than but were damaged by higher image noise. B–D Another 57-year woman with a BMI of 20.8 kg/m.2 underwent abdominal CTA using a FD protocol with CTDIvol, DLP, SSDE, and effective dose of 4.06 mGy, 111.0 mGy·cm, 6.25 mGy, and 1.67 mSv, respectively. The data were reconstructed into FD_UHR_Bv48, and FD_SR_Bv40 images, respectively. B The left gastric artery is only visible in axial FD_UHR_Bv48 images (solid arrow), and the soft tissue between the abdominal aorta and celiac trunk were better depicted (open arrow). C There were more visible vascular segments of left renal artery in coronal FD_UHR_Bv48 images than FD_SR_Bv40 images (solid arrow). D The left renal artery can be better visualized to the more distal vascular segments in volume-rendered FD_UHR_Bv48 images than FD_SR_Bv40 images (solid arrow). The volume-rendered FD_UHR_Bv48 images allowed more visible vascular segments of superior mesenteric artery (open arrow).

Protocol

Detail

Value

Scanner

NAEOTOM Alpha

Software

Syngo.CT VA50-SP1; syngo.via VB60

Scan area

Abdominal CTA

Scan mode

UHR

Acquisition mode

PCCT

Tube voltage [kV]

120

Effective mAs [mAs]

CARE Dose4D automatic

IQ level

145 full dose; 90 low dose

Dose modulation

CARE Dose4D

CTDIvol [mGy]

Protocol-dependent; significantly lower with low-dose protocol

DLP [mGy·cm]

Protocol-dependent; significantly lower with low-dose protocol

Temporal resolution [ms]

n.a.

Rotation time [s]

0.50

Pitch

0.8

Matrix

Automatically adjusted

Field of view [mm]

Automatically adjusted

Detector slice collimation

120 × 0.2 mm

Acquisition slice thickness

0.2 mm

Slice width [mm]

UHR: 0.2; SR: 1.0

Reconstruction increment [mm]

UHR: 0.2; SR: 0.7

Reconstruction kernel

UHR: Bv48, Bv56, Bv60; SR: Bv40

Iterative reconstruction

UHR: QIR 4; SR: QIR 3

Reconstruction

UHR polychromatic vs standard-resolution 40-keV VMI

Reconstruction comparison

FD_UHR_Bv48, FD_UHR_Bv56, FD_UHR_Bv60, FD_SR_Bv40, LD_UHR_Bv48, LD_SR_Bv40

Contrast agent

Ultravist 370

Contrast volume

1.5 mL/kg

Saline flush

n.a.

Injection rate

3.0 mL/s

Bolus triggering

Abdominal aorta

Arterial phase

12-s delay after aortic enhancement

Additional reconstructions

Axial, coronal, volume-rendered images

Key Results

Parameter

Main finding

Study population

94 participants; 47 full dose + 47 low dose

SNR / CNR

Significantly higher with 1-mm 40-keV VMI than UHR, P < 0.001

Vessel sharpness

Highest with UHR Bv56/Bv60, but with substantially more noise

Best UHR balance

0.2-mm Bv48 provided comparable overall quality to 40-keV VMI

Artery visibility

No significant overall difference among the six reconstruction series

Preferred strategy

Low-dose 1-mm 40-keV VMI for routine CTA; 0.2-mm UHR Bv48 when thinner slices are required

Source:
Zhang H, Xing Y, Wang L, Hu Y, Xu Z, Chen H, Lu J, Yang J, Ding B, Hu W, Zhong J. Ultra-High-Resolution Photon-Counting Detector CT Benefits Visualization of Abdominal Arteries: A Comparison to Standard-Reconstruction. Journal of Imaging Informatics in Medicine. 2025;38:1891–1903. doi:10.1007/s10278-024-01232-5.

]]> (2024) Wang | Low-dose ultra-high-resolution PCCT for visceral artery CTA https://connect.siemens-healthineers.com/ja/discussion/496/2024-wang-low-dose-ultra-high-resolution-pcct-for-visceral-artery-cta Fri, 28 Aug 2026 10:12:50 +0000 Scientific publications Daniel Stromer 496@/ja/discussions

Prospective study testing whether low-dose (LD) ultra-high-resolution (UHR) photon-counting CT can preserve diagnostic image quality for visceral artery CTA. The study included 57 patients in the full-dose group and 57 in the low-dose group.


Each acquisition was reconstructed two ways: 0.2 mm / Bv48 / QIR 4 and 1 mm / Bv40 / QIR 3. Objective SNR/CNR and subjective noise, vessel sharpness, overall quality, and visibility of nine visceral arteries were assessed.


The 0.2-mm UHR reconstruction had lower SNR and CNR than the 1-mm reconstruction, but nevertheless achieved better qualitative image quality, particularly for depiction of tiny arteries on volume-rendered images (p < 0.001).


Importantly, full-dose imaging generally did not provide significantly higher SNR/CNR than low-dose imaging at the same slice thickness. Exceptions were SNR for the common hepatic, splenic, and bilateral renal arteries with the 0.2-mm reconstruction.


Low-dose scanning also did not significantly impair image quality in overweight patients within the same reconstruction setting.


Visibility of the nine evaluated visceral arteries was largely comparable between full- and low-dose protocols, with limited exceptions involving the superior mesenteric and left gastric arteries.

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Practical PCCT takeaway

The study supports using low-dose UHR PCCT for visceral CTA while retaining very thin 0.2-mm reconstructions. Rather than sacrificing spatial resolution to improve conventional SNR/CNR metrics, UHR PCCT can exploit thin slices to improve depiction of small arterial anatomy. The authors conclude that low-dose UHR was adequate for clinical visceral-artery evaluation and that 0.2-mm reconstruction particularly improves small-vessel depiction.

Protocol

NAEOTOM Alpha PCCT; UHR acquisition; 57 FD + 57 LD patients; 0.2-mm/Bv48/QIR4 versus 1-mm/Bv40/QIR3 reconstructions.

Source: Wang L, Hu Y, Zhong J, et al. Low-dose Ultra-high-resolution Photon-Counting Detector CT for Visceral Artery CT Angiography: A Preliminary Study. Academic Radiology. 2024;31(12):5087–5099. doi:10.1016/j.acra.2024.06.044. Published online August 6, 2024.

]]> (2023) Schade | Pseudoenhancement of renal cysts on PCCT https://connect.siemens-healthineers.com/ja/discussion/495/2023-schade-pseudoenhancement-of-renal-cysts-on-pcct Fri, 28 Aug 2026 10:10:05 +0000 Scientific publications Daniel Stromer 495@/ja/discussions

In 86 patients with 160 non-enhancing renal cysts, the study assessed how PCCT virtual monoenergetic image (VMI) energy level affects apparent renal cyst enhancement and therefore lesion classification.


Low-keV VMI substantially increased apparent cyst attenuation: mean attenuation rose from 4 ± 11 HU at 190 keV to 36 ± 17 HU at 40 keV.


This produced marked pseudoenhancement at low energies: at 40 keV, 35% of cysts appeared equivocally enhancing and 46% definitely enhancing; at 50 keV, these rates were 29% and 10%, respectively. At 60 keV, 9% were equivocal but none definitely enhancing.


Importantly, no cyst was classified as enhancing at 70–190 keV, indicating that ≥70-keV VMI provides substantially more reliable assessment of true renal cyst enhancement.

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Practical PCCT takeaway:

Low-keV reconstructions are attractive for increasing iodine conspicuity, but they should not be used uncritically for HU-based renal lesion characterization. For renal cyst enhancement, 70 keV appears to be a safer reference reconstruction in this study.

The observed misclassification was not significantly dependent on cyst size, location, or patient BMI, suggesting that the VMI energy itself is the dominant issue.

Protocol:

Clinical PCCT, 120 kVp, image-quality level 68; triphasic examination. Venous-phase VMIs were reconstructed from 40–190 keV in 10-keV increments. Only cysts ≥7 mm confirmed as non-enhancing (<10 HU difference between unenhanced and venous 70-keV images) were analyzed.

Source: Schade KA, Mergen V, Sartoretti T, Alkadhi H, Euler A. Pseudoenhancement in Cystic Renal Lesions – Impact of Virtual Monoenergetic Images of Photon-Counting Detector CT on Lesion Classification. Academic Radiology. 2023;30(Suppl 1):S305-S313. doi:10.1016/j.acra.2023.04.005. Published online May 5, 2023.

]]> (2026) Huang | UHR PCCT with low-keV improves preoperative pancreatic cancer assessment https://connect.siemens-healthineers.com/ja/discussion/489/2026-huang-uhr-pcct-with-low-kev-improves-preoperative-pancreatic-cancer-assessment Fri, 28 Aug 2026 06:11:40 +0000 Scientific publications Daniel Stromer 489@/ja/discussions

Combining UHR PCCT with low-keV virtual monoenergetic imaging (VMI) improved visualization of pancreatic ductal adenocarcinoma (PDAC), peripancreatic vessels, and fine pancreatic anatomy; the study identified 0.4-mm slices at 45 keV as the best overall reconstruction strategy for preoperative assessment.


40-keV VMI produced the highest quantitative CNR and SNR for tumors and peripancreatic vessels, while 45–50 keV at 0.4-mm slice thickness achieved better qualitative visualization of fine anatomical structures, balancing spectral contrast enhancement with the high spatial resolution of PCCT.


The combination of high spatial resolution and spectral information from PCCT may improve tumor–vessel delineation and visualization of fine structures relevant to PDAC staging and surgical planning, demonstrating the complementary value of UHR acquisition and spectral reconstruction in abdominal oncology imaging.

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Image taken from LinkedIn:

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Source: Huang R, Yang Y, Gao M, et al. Eur J Radiol. 2026;195:112596.

]]> (2022) Mergen | Virtual noncontrast abdominal imaging with PCCT https://connect.siemens-healthineers.com/ja/discussion/487/2022-mergen-virtual-noncontrast-abdominal-imaging-with-pcct Thu, 27 Aug 2026 17:36:07 +0000 Publication protocols Daniel Stromer 487@/ja/discussions

Virtual noncontrast (VNC) images reconstructed from contrast-enhanced PCCT provided accurate abdominal attenuation values compared with true noncontrast (TNC) imaging, supporting the potential to omit a separate TNC acquisition.


Across all measurements, VNC attenuation errors were <5 HU in 76% and <10 HU in 95%; there was no meaningful overall difference between VNC reconstructed from arterial versus portal venous acquisitions.


VNC had inferior image quality and higher/blotchier noise than TNC, but remained diagnostically usable in 99–100% of patients.

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Figure 2: CT attenuation measurements in a 58-year-old man referred for follow-up examination after an acute type B aortic dissection. Axial CT images acquired with photon-counting detector CT depict exemplary region-of-interest (ROI) measurements on venous virtual noncontrast reconstructions. avg = average attenuation within region of interest; d = diameter of region of interest.

Protocol

Detail

Value

Scanner

NAEOTOM Alpha

Detector

Dual-source, two cadmium telluride PCDs

Scan area

Thoracoabdominal

Scan phases

TNC + arterial + portal venous

Acquisition mode

Single-source multienergy, QuantumPlus

Tube voltage [kV]

120

Tube current

Automated modulation, CARE Dose4D / CARE kV

IQ level

68

Rotation time [s]

0.25

Pitch

1.2

Detector slice collimation

144 × 0.4 mm

Contrast

70 mL iopromide, 370 mg I/mL

Injection rate

4 mL/s

Arterial timing

Bolus tracking; 140 HU threshold at 90 kV + 12-s delay

Portal venous timing

70 s after contrast injection

Reconstruction kernel

Br36

Iterative reconstruction

QIR 4

Slice thickness [mm]

2.0

Reconstruction increment [mm]

1.6

Reconstruction plane

Axial

VNC source phases

Arterial and portal venous

Reference standard

True noncontrast (TNC) images

Key Results

Parameter

Main finding

Study population

100 patients; mean age 72 ± 10 years; 81 men

Overall VNC error <5 HU

76% of measurements

Overall VNC error <10 HU

95% of measurements

Arterial vs venous VNC error

3.3 vs 3.5 HU; P = .16

Left liver attenuation error

1.4 ± 1.3 HU arterial VNC; 1.5 ± 1.2 HU venous VNC

Liver error <5 HU

Left lobe 99%; right lobe 98% for both arterial and venous VNC

Diagnostic subjective quality

99–100%

VNC noise

33% higher than TNC in phantom

Noise texture

VNC more blotchy; average spatial frequency 0.14 vs 0.20 mm⁻¹

Spatial resolution

Similar overall; TTF50 0.29 mm⁻¹ for both

Detectability index

VNC approximately 15% lower, but always >20

The liver showed particularly small VNC attenuation errors, with left-lobe mean errors around 1.5 HU. Phantom testing confirmed higher and blotchier VNC noise but similar middle-frequency spatial resolution and a detectability index consistently above 20.

Take-home: PCCT VNC can provide quantitatively accurate abdominal attenuation without a dedicated noncontrast acquisition. The principal trade-off is higher, blotchier image noise and somewhat poorer subjective image quality, although diagnostic quality remained very high.

Source: Mergen V, Racine D, Jungblut L, et al. Virtual Noncontrast Abdominal Imaging with Photon-counting Detector CT. Radiology. 2022;305(1):107–115. doi:10.1148/radiol.213260.

]]> (2024) Khanungwanitkul | PCCT reveals pancreatic duct connection of a side-branch IPMN https://connect.siemens-healthineers.com/ja/discussion/485/2024-khanungwanitkul-pcct-reveals-pancreatic-duct-connection-of-a-side-branch-ipmn Thu, 27 Aug 2026 17:21:38 +0000 Case reports Daniel Stromer 485@/ja/discussions

This case report has been published in Radiology.

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Figure 1. Axial photon-counting CT images at (A) 0.4-mm, (C) 2-mm, and (D) 4-mm section thickness demonstrate an incidental hypoattenuating pancreatic lesion (arrowhead). The lesion communicates with the main pancreatic duct via a connection (arrow) visible at 0.4-mm section thickness. (B) Iodine overlay image at 0.4-mm section thickness displays iodine content in orange, demonstrating no uptake within the hypoattenuating lesion or main duct communication.

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Figure 2. Coronal cinematic rendering of the intraductal papillary mucinous neoplasm (arrowhead) in relation to the pancreatic duct

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Figure 3. Axial T2-weighted image at 5-mm section thickness from MR cholangiopancreatography confirms the cystic nature of the lesion (arrow) but does not show the connection to the main pancreatic duct.

Source: Khanungwanitkul K, Schwartz FR. Photon-Counting CT Shows Side-Branch Intraductal Papillary Mucinous Neoplasm–Pancreatic Duct Connection. Radiology. 2024;312(2). doi:10.1148/radiol.240611.

]]> (2024) Huflage | Submillisievert PCCT for urinary calculi detection https://connect.siemens-healthineers.com/ja/discussion/484/2024-huflage-submillisievert-pcct-for-urinary-calculi-detection Thu, 27 Aug 2026 17:14:44 +0000 Publication protocols Daniel Stromer 484@/ja/discussions

Retrospective single-center study of 507 patients undergoing unenhanced abdominal CT for suspected urinary calculi, comparing PCCT (n = 229) with optimized EID-CT (n = 278).


PCCT achieved a 44% lower effective radiation dose than EID-CT: 0.79 mSv vs 1.39 mSv, while maintaining excellent diagnostic confidence.


Despite the lower dose, PCCT provided higher SNR, with improvements of 30% at the kidney, 23% at the psoas, and 17% at the obturator level. Interreader agreement for calculus detection was near perfect (Krippendorff α ≥ 0.99).

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Figure 2. Axial contrast-unenhanced abdominal CT examinations in a 38-year-old female patient with a body mass index (calculated as weight in kilograms divided by height in meters squared) of 31.23 with known renal calculi for recurring events of flank pain. The patient underwent (A) dose-optimized energy-integrating detector CT (1.49 mSv) and (B) submillisievert photon-counting detector CT (0.94 mSv). Images from both examinations showed a 3-mm calculus in the left kidney (arrows).

Protocol

Detail

Value

Scanner

NAEOTOM Alpha

Scan area

Abdomen / urinary tract

Scan mode

Unenhanced ultra-low-dose CT

Acquisition mode

PCCT with tin prefiltration

Tin filter

0.4 mm

Tube voltage [kV]

Sn 100 / Sn 140, automatic selection

Tube current

Automatic

IQ level

20

Rotation time [s]

0.5

Detector slice collimation

144 × 0.4 mm

Reconstruction kernel

Br36

Reconstruction

Iterative reconstruction, strength 3

Slice thickness

1 mm

Contrast agent

None

Key results

Parameter

PCCT

EID-CT

Patients

229

278

CTDIvol

1.17 mGy

1.99 mGy

Effective dose

0.79 mSv

1.39 mSv

Dose reduction

44%

—

Image noise

15.88 HU

21.24 HU

Kidney SNR

2.15

1.66

Psoas SNR

3.01

2.44

Obturator SNR

3.25

2.79

Diagnostic confidence

5/5

5/5

Interreader agreement

α ≥ 0.99

α ≥ 0.99

PCCT therefore enabled submillisievert urinary stone imaging with simultaneous dose reduction and improved objective image quality, without loss of reader confidence.

Source: Huflage H, Kunz AS, Patzer TS, et al. Submillisievert Abdominal Photon-Counting CT versus Energy-integrating Detector CT for Urinary Calculi Detection: Impact on Diagnostic Confidence. Radiology. 2024;312(1). doi:10.1148/radiol.232453.

]]> (2024) Rau | PCCT virtual non-contrast imaging accurately characterizes uncomplicated renal cysts https://connect.siemens-healthineers.com/ja/discussion/478/2024-rau-pcct-virtual-non-contrast-imaging-accurately-characterizes-uncomplicated-renal-cysts Wed, 26 Aug 2026 08:18:18 +0000 Publication protocols Daniel Stromer 478@/ja/discussions

PCCT-derived virtual non-contrast (VNC) images provided renal cyst attenuation measurements comparable to true non-contrast imaging, with no significant difference across true non-contrast, arterial VNC, and portal-venous VNC (p = 0.301).


In contrast, dual-energy EID-CT VNC showed a significant difference from true non-contrast attenuation (p = 0.02) and produced false-positive enhancement >20 HU in 5/19 lesions (26.3%).


With PCCT, all evaluated cysts remained below the 20-HU enhancement threshold on both arterial and portal-venous VNC, supporting VNC as a potential replacement for true non-contrast imaging in uncomplicated renal cyst characterization.

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Figure 2. Example of Density-measurements in a simple renal cyst on EID DE-CT and PCCT images using true non-contrast, portal venous and virtual non-contrast derived images (from left to right). While true enhancement is < 20 HU, EID DE-CT VNC-derived values are remarkably low leading to false-positive enhancement > 20 HU. PCCT = photon-counting CT; DE EID-CT = dual-energy integrating detector CT.

Protocol

Detail

Value

Scanner

NAEOTOM Alpha

Scan area

Abdomen

Acquisition

Multiphase PCCT

Scan mode

QuantumPlus

Phases

True non-contrast, arterial, portal venous

Tube voltage [kVp]

120

Tube current

Automated attenuation-based modulation

IQ level

100 (non-contrast & arterial); 145 (portal venous)

Effective mAs [mAs]

99 (non-contrast); 100 (arterial & portal venous)

Rotation time [s]

0.5

Pitch

0.8

Collimation

144 × 0.40 mm

Contrast agent

Iopromide (Ultravist 370 mg iodine/mL)

Contrast amount

Body-weight adapted, 1.2 mg/kg as reported

Injection / saline flush

4.0 mL/s; 40 mL saline

Arterial timing

Bolus tracking, descending aorta, 100-HU threshold

Portal venous timing

80 s after contrast administration

Reconstruction

70-keV virtual monoenergetic images

Kernel

Br40

Slice thickness [mm]

3.0

Increment [mm]

3.0

Iterative reconstruction

QIR 4

Spectral reconstruction

Arterial VNC + portal-venous VNC

Reference imaging

MRI and/or ultrasound

Key Results

Parameter

Main finding

Study cohort

19 patients / 19 simple renal cysts

PCCT true non-contrast attenuation

13.7 ± 11.6 HU

PCCT arterial VNC

9.27 ± 10.1 HU

PCCT portal-venous VNC

12.3 ± 9.9 HU

PCCT attenuation comparison

No significant difference, p = 0.301

PCCT arterial VNC enhancement

4.5 ± 5.0 HU, range −6.2 to 14.2

PCCT portal-venous VNC enhancement

2.4 ± 5.3 HU, range −6.4 to 13.5

PCCT false-positive enhancement >20 HU

0/19 (0%)

DE EID-CT false-positive enhancement >20 HU

5/19 (26.3%)

Portal-venous CTDIvol

PCCT 8.66 mGy vs DE EID-CT 10.95 mGy, p < 0.001

Clinical implication

PCCT VNC may potentially substitute true non-contrast imaging for simple renal cyst characterization

The authors conclude that PCCT VNC provided reliable characterization comparable to true non-contrast imaging, while DE EID-CT VNC falsely characterized 26% of lesions; consequently, PCCT VNC could potentially reduce true non-contrast acquisitions, radiation exposure, and unnecessary follow-up imaging.

Source:
Rau S, Rau A, Stein T, et al. Value of virtual non-contrast images to identify uncomplicated cystic renal lesions: photon-counting detector CT vs. dual-energy integrating detector CT. La Radiologia Medica. 2024;129:669–676. doi:10.1007/s11547-024-01801-2.

]]> (2024) Lin | PCCT enables protocol-independent liver fat quantification https://connect.siemens-healthineers.com/ja/discussion/477/2024-lin-pcct-enables-protocol-independent-liver-fat-quantification Wed, 26 Aug 2026 08:11:31 +0000 Publication protocols Daniel Stromer 477@/ja/discussions

PCCT-derived fat fraction (CTFF) showed excellent agreement with MRI proton density fat fraction (PDFF), supporting quantitative liver fat assessment using standardized PCCT attenuation values.


A single conversion formula—MRI PDFF (%) = −0.58 × CT (HU) + 43.1—remained accurate across 90, 120, and 140 kVp and both standard- and low-dose protocols.


Accuracy was maintained across different BMI and steatosis levels, while validation in patients with MASLD showed an ICC of 0.96 and a mean bias of only −0.2%, supporting PCCT as a potential tool for opportunistic liver fat quantification.

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Figure 2. Liver fat content measurement with photon-counting detector (PCD) CT and MRI-based proton density fat fraction (PDFF). Three regions of interest (circles) were delineated in the peripheral areas of the left, right anterior, and right posterior lobes of the liver. (A) Representative axial unenhanced 120-kVp standard-dose CT image (left) and corresponding MRI scan (right) in a 33-year-old man (body mass index, 26.2) diagnosed with metabolic dysfunction–associated steatotic liver disease (MASLD) in the asymptomatic cohort. (B) Representative axial unenhanced 120-kVp low-dose CT image (left) and corresponding MRI scan (right) in a 69-year-old woman (body mass index, 24.6) in the MASLD cohort. Body mass index was calculated as weight in kilograms divided by height in meters squared. FF = fat fraction.

Protocol

Detail

Value

Scanner

NAEOTOM Alpha

Software

VA50

Scan area

Entire liver and spleen

Scan mode

Spiral

Acquisition mode

QunatumPlus

Tube voltage [kV]

90, 120, 140

Effective mAs [mAs]

CARE Dose4D automatic

IQ level

90 (low dose), 145 (standard dose)

Dose modulation

CARE Dose4D

Rotation time [s]

0.25

Pitch

0.8

Detector slice collimation

144 × 0.4 mm

Slice thickness [mm]

1.0

Reconstruction increment [mm]

0.7

Reconstruction kernel

Br40

Iterative reconstruction

QIR 3

Reconstruction

70-keV virtual monoenergetic images

Contrast agent

None

Postprocessing

syngo.via MM Reading, VB60

Reference standard

MRI PDFF

Key Results

Parameter

Main finding

Conversion formula

MRI PDFF (%) = −0.58 × CT (HU) + 43.1

Asymptomatic validation

ICC 0.94; mean bias 0.04% ± 2.3

Protocol robustness

ICC 0.93–0.94 across 90–140 kVp; 0.95 low dose and 0.93 standard dose

CTFF error

Not significantly influenced by tube voltage, radiation dose, steatosis, or BMI

MASLD validation

ICC 0.96; mean bias −0.2% ± 2.1

Clinical implication

Standardized PCCT attenuation may enable protocol-independent quantitative and opportunistic liver fat assessment

Source:
Lin H, Xu X, Deng R, et al. Photon-counting Detector CT for Liver Fat Quantification: Validation across Protocols in Metabolic Dysfunction–associated Steatotic Liver Disease. Radiology. 2024;312(3). doi:10.1148/radiol.240038.

]]> (2023) Graafen | Soft Reconstruction Kernels Improve HCC Imaging on a PCCT https://connect.siemens-healthineers.com/ja/discussion/473/2023-graafen-soft-reconstruction-kernels-improve-hcc-imaging-on-a-pcct Sat, 08 Aug 2026 07:00:52 +0000 Scientific publications Daniel Stromer 473@/ja/discussions

In a phantom and clinical study involving 24 patients with viable hepatocellular carcinoma (HCC), Graafen et al. evaluated reconstruction kernels for triple-phase photon-counting detector CT (PCD-CT), using 50-keV virtual monoenergetic images. Image quality was assessed quantitatively through contrast-to-noise ratio (CNR) and edge sharpness and qualitatively by three readers.

The softest reconstruction kernels (sharpness level 36) produced the highest CNR across all contrast phases (all p < 0.05) without significantly reducing lesion sharpness. Softer kernels were also rated significantly better for image noise and overall image quality, although image contrast and HCC lesion conspicuity did not significantly differ between kernels. There was also no meaningful image-quality difference between regular body and quantitative kernels at equivalent sharpness levels.

Bottom line: For HCC assessment with photon-counting CT, soft reconstruction kernels provide the best overall image quality. The authors specifically recommend quantitative soft kernels, because they maintain comparable image quality while preserving the possibility of subsequent spectral post-processing.

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Source: Graafen D, Müller L, Halfmann MC, et al. Soft Reconstruction Kernels Improve HCC Imaging on a Photon-Counting Detector CT. Academic Radiology. 2023;30(Suppl 1):S143–S154. doi:10.1016/j.acra.2023.03.026.

]]> (2024) Dillinger | Low-keV VMI from portal venous PCCT enhances abdominal arterial contrast https://connect.siemens-healthineers.com/ja/discussion/472/2024-dillinger-low-kev-vmi-from-portal-venous-pcct-enhances-abdominal-arterial-contrast Sat, 08 Aug 2026 06:57:15 +0000 Publication protocols Daniel Stromer 472@/ja/discussions

This retrospective study of 40 patients evaluated whether virtual monoenergetic images (VMI) reconstructed from portal venous PCCT could provide sufficient arterial vessel contrast and potentially serve as an alternative when a dedicated arterial phase is unavailable or suboptimal.

40-keV VMI produced the highest arterial attenuation, reaching 439 ± 97 HU versus 360 ± 97 HU on true polychromatic arterial images, corresponding to approximately 18% higher vessel attenuation. This gain came at the cost of increased noise and substantially lower CNR and SNR.

Subjectively, 40 keV provided the best vascular contrast, whereas 70 keV provided the best overall image quality and represented a more balanced reconstruction with improved noise, CNR, and SNR compared with 40 keV. The findings suggest low-keV VMI may help salvage arterial information from portal venous PCCT datasets and potentially avoid repeat examinations in selected cases.

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Figure 2. The same CT slice with pv contrast (center 130, width 550) at 40 keV (a), 70 keV (b), 100 keV (c), and 190 keV (d). (a) demonstrates major image noise with acceptable image quality and optimal vessel contrast. (b) shows no noise with a good vessel assessability and optimal image quality. (c) shows no noise, acceptable quality, and poor vascular contrast. (d) demonstrates no noise, no vessel contrast, and poor image quality.

image.png

Protocol

Detail

Value

Scanner

NAEOTOM Alpha

Application

Contrast-enhanced abdominal PCCT / abdominal arterial vessel assessment

Study design

Retrospective

Study population

40 patients

Acquisition phases

Arterial and portal venous

Scan direction

Cranio-caudal

Tube voltage

120 kV

Pitch

0.80

Reconstruction increment

0.70 mm

Slice thickness

1.0 mm

Reconstruction kernel

Qr40

Postprocessing

Monoenergetic+

Workstation

Syngo.via VB60A_HF04

Contrast agent

Xenetix 350 (iobitridol)

Contrast volume

100 mL

Saline chaser

50 mL

Injector

CT Motion XD8000

Arterial bolus triggering

CARE Bolus, threshold 140 HU

Arterial phase delay

7 s after threshold

Portal venous phase delay

55 s

Analyzed vessels

Descending aorta, coeliac trunk, superior mesenteric artery, bilateral renal arteries, bilateral common iliac arteries

Objective endpoints

Vessel attenuation, noise, SNR, CNR

Subjective endpoints

Overall image quality, arterial vessel contrast, image noise using 5-point Likert scales

Key Results

Parameter

Main finding

Arterial attenuation

40-keV portal venous VMI: 439 ± 97 HU vs 360 ± 97 HU for true arterial polychromatic images (p < 0.001)

Contrast gain at 40 keV

Approximately 18% higher arterial attenuation than the true arterial phase

Best vascular contrast

40 keV provided the highest objective attenuation and best subjective arterial vessel contrast

Noise

Highest at 40 keV and progressively decreased with increasing energy; VMI at ≥70 keV generally showed lower noise than arterial polychromatic images

CNR

True arterial images: 25.10 ± 9.38; highest portal venous VMI CNR at 60 keV: 8.64 ± 3.58

SNR

True arterial images: 20.10 ± 8.30; all portal venous VMI levels had significantly lower SNR

Best overall image quality

70 keV

Reader agreement

Substantial agreement for vessel contrast (κ = 0.799), image quality (κ = 0.742), and noise (κ = 0.712)

Main implication

40-keV VMI can substantially enhance arterial contrast from portal venous PCCT, potentially allowing assessment of arterial vessels after suboptimal contrast timing or reducing the need for repeat/dedicated arterial acquisitions in selected cases.

Source:
Dillinger D, Overhoff D, Ayx I, Kaatsch HL, Hagen A, Schönberg SO, Waldeck S. Optimizing Arterial Vessel Contrast in Portal Venous Phase with Virtual Monoenergetic Images from Photon-Counting Detector CT Scans of the Abdomen—First Clinical Experiences. Diagnostics. 2024;14(6):627. doi: 10.3390/diagnostics14060627.

]]> (2022) Decker | PCCT enables anemia detection from routine contrast-enhanced CT https://connect.siemens-healthineers.com/ja/discussion/471/2022-decker-pcct-enables-anemia-detection-from-routine-contrast-enhanced-ct Sat, 08 Aug 2026 06:50:37 +0000 Scientific publications Daniel Stromer 471@/ja/discussions

This proof-of-concept study demonstrates that spectral PCCT data from routine contrast-enhanced oncologic staging examinations can be used to detect and quantify anemia by measuring blood-pool attenuation on virtual non-contrast (VNC) images.

Mean blood-pool VNC attenuation showed a strong positive correlation with hemoglobin (R² = 0.81) and hematocrit (R² = 0.77), indicating that decreasing VNC attenuation closely reflects increasing anemia severity.

VNC attenuation progressively decreased from no anemia to mild, moderate, and severe anemia, demonstrating the potential for opportunistic identification of previously unknown or worsening anemia directly from routinely acquired contrast-enhanced PCCT examinations.

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Key Results

Parameter

Main finding

Study population

179 oncologic patients; mean age 68 ± 11 years; 77 women and 102 men

Hemoglobin correlation

Mean VNC blood-pool attenuation strongly correlated with hemoglobin: R² = 0.81 (95% CI: 0.76–0.86; P < .001)

Hematocrit correlation

Strong correlation with hematocrit: R² = 0.77 (95% CI: 0.70–0.82; P < .001)

Women – no anemia

Mean VNC attenuation 44.2 ± 3.6 HU

Women – mild anemia

40.6 ± 2.0 HU

Women – moderate anemia

35.2 ± 3.6 HU

Women – severe anemia

25.0 ± 3.5 HU

Men – no anemia

Mean VNC attenuation 46.4 ± 3.5 HU

Men – mild anemia

41.8 ± 2.5 HU

Men – moderate anemia

36.4 ± 3.6 HU

Men – severe anemia

33.3 ± 1.2 HU

Main implication

Spectral PCCT VNC imaging may provide an opportunistic quantitative marker of anemia from routine contrast-enhanced examinations without requiring a dedicated non-contrast acquisition.

Source:
Decker JA, Huber A, Senel F, Bette S, Braun F, Risch F, Woźnicki P, et al. Anemia Detection by Hemoglobin Quantification on Contrast-enhanced Photon-counting CT Data Sets. Radiology. 2022;305(3):650–652. doi: 10.1148/radiol.220063.

]]> (2024) Dane | Pancreatic cyst prevalence and detection with PCCT compared with EID-CT https://connect.siemens-healthineers.com/ja/discussion/470/2024-dane-pancreatic-cyst-prevalence-and-detection-with-pcct-compared-with-eid-ct Sat, 08 Aug 2026 06:45:24 +0000 Scientific publications Daniel Stromer 470@/ja/discussions

In a retrospective single-center study of 2,494 patients, photon-counting CT (PCCT) demonstrated a significantly higher pancreatic cyst detection rate than conventional energy-integrating detector CT (EIDCT): 4.9% (49/1,009) vs 3.0% (44/1,485), p = 0.017.

The largest difference occurred with CT angiography, where cysts were detected in 6.6% with PCCT versus 0% with EIDCT (p < 0.001). Among patients with prior conventional CT examinations, PCCT-detected cysts were also more frequently newly reported (40.7% vs 14.8%, p = 0.027).

Cyst size did not differ significantly between modalities. Overall, the findings suggest that PCCT improves detection and conspicuity of pancreatic cysts compared with conventional CT, particularly on CT angiographic examinations.

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Source: Dane B, Kim J, Qian K, Megibow A. Pancreatic cyst prevalence and detection with photon counting CT compared with conventional energy integrating detector CT. European Journal of Radiology. 2024;175:111437. doi:10.1016/j.ejrad.2024.111437.

]]> (2024) Bette | PCCT virtual non-contrast imaging differentiates adrenal adenomas from metastases https://connect.siemens-healthineers.com/ja/discussion/469/2024-bette-pcct-virtual-non-contrast-imaging-differentiates-adrenal-adenomas-from-metastases Sat, 08 Aug 2026 06:39:31 +0000 Publication protocols Daniel Stromer 469@/ja/discussions

PCCT virtual non-contrast (VNC) reconstructions differentiated adrenal adenomas from metastases on portal-venous contrast-enhanced imaging, with adenomas showing significantly lower attenuation on both conventional VNC (VNCConv) and calcium-preserving PureCalcium VNC (VNCPC) (p = 0.007).

VNC nevertheless systematically overestimated attenuation compared with true non-contrast (TNC) imaging: mean differences were 17.67 HU for VNCConv and 14.85 HU for VNCPC, indicating that the conventional 10-HU TNC threshold cannot simply be transferred to PCCT VNC.

Diagnostic performance was particularly strong for VNCPC (AUC 0.931) and when combining all available spectral information (AUC 0.938). For VNCConv, a higher threshold of 26 HU achieved 86.7% sensitivity and 75.6% specificity, supporting a PCCT-specific VNC threshold for adrenal lesion characterization.

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Figure 1. Example of semiautomatic segmentation of a left adrenal adenoma using 3D Slicer.

Protocol

Detail

Value

Scanner

NAEOTOM Alpha

Application

Contrast-enhanced abdominal CT / adrenal lesion characterization

Study design

Retrospective, single-center

Acquisition mode

Abdomen QuantumPlus with spectral information

Contrast phase

Portal venous

Scan direction

Craniocaudal

Patient position

Supine

Breath-hold

Single breath-hold

Tube voltage

120 kV

Rotation time

0.5 s or 0.25 s

Collimation

144 × 0.4 mm

Slice thickness

1.0 mm

Reconstruction increment

0.5 mm

Reconstruction kernel

Qr40

Iterative reconstruction

QIR 3

Reconstruction software

ReconCT 16.0

TNC reconstruction software

Syngo.via VB60A

VNC reconstructions

Conventional VNC (VNCConv) and PureCalcium VNC (VNCPC)

VNC energy

70 keV

Virtual monoenergetic images

40–90 keV in 10-keV increments

Additional spectral reconstruction

Iodine maps

Contrast agent

Ultravist 300 mg I/mL

Contrast volume

100 mL

Flow rate

4.0 mL/s

Saline chaser

30 mL

Scan delay

Fixed 75 s after contrast injection

True non-contrast imaging

Available in 49/90 patients; obtained either within the same protocol or from a separate CT acquisition

Lesion analysis

Semiautomatic whole-lesion 3D segmentation

Segmentation software

3D Slicer

Primary comparison

VNCConv and VNCPC vs TNC; spectral imaging for adenoma vs metastasis differentiation

Key Results

Parameter

Main finding

Study population

90 patients; 45 adrenal adenomas and 45 metastases

VNCConv attenuation

Adenomas 18.15 HU [12.92–24.26] vs metastases 31.28 HU [26.00–35.89]; p = 0.007

VNCPC attenuation

Adenomas 16.00 HU [11.02–21.56] vs metastases 27.22 HU [22.59–30.64]; p = 0.007

VNCConv vs TNC

VNCConv overestimated attenuation by a mean 17.67 HU

VNCPC vs TNC

VNCPC overestimated attenuation by a mean 14.85 HU

All spectral features

AUC 0.938 for adenoma/metastasis discrimination

VNCPC alone

AUC 0.931

VNCConv alone

AUC 0.857

TNC alone

AUC 0.762

VNCConv 26-HU cutoff

86.7% sensitivity, 75.6% specificity

Feature importance

VNCConv and VNCPC were the most important discriminators in random-forest feature selection

Main implication

PCCT VNC may enable adrenal lesion characterization from contrast-enhanced scans, potentially reducing additional dedicated adrenal CT/MRI examinations, but requires a higher VNC-specific HU threshold rather than direct application of the conventional 10-HU TNC cutoff.

Source:
Bette S, Risch F, Canalini L, Becker J, Leithner EV, Huber A, Haerting M, Jehs B, Wollny C, Schwarz F, Tehlan K, Scheurig-Muenkler C, Wendler T, Kroencke T, Decker JA. Diagnostic performance of photon-counting detector CT for differentiation between adrenal adenomas and metastases. European Radiology. 2024;34:5944–5953.

]]> (2022) Bette | Low-keV PCCT improves conspicuity of hypovascularized liver metastases https://connect.siemens-healthineers.com/ja/discussion/468/2022-bette-low-kev-pcct-improves-conspicuity-of-hypovascularized-liver-metastases Sat, 08 Aug 2026 06:35:12 +0000 Publication protocols Daniel Stromer 468@/ja/discussions

PCCT virtual monoenergetic imaging (VMI) improved visualization of hypovascularized liver metastases, with the greatest lesion conspicuity and CNR achieved at the low end of the keV spectrum. At 40 keV, tumor-to-liver ratio (TLR) reached 0.37, while CNR peaked at 6.88.

Compared with conventional EID-CT, PCCT showed lower image noise at 70 keV (15.4 vs. 17.1 HU), while VMI below 70 keV produced higher lesion CNR and greater tumor-to-liver contrast.

The advantage was particularly relevant in patients with higher BMI: around the clinically relevant 60–80 keV range, PCCT maintained image noise and largely preserved CNR despite a more moderate CTDI upregulation than EID-CT.

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Figure 4. Example of PCD-VMIs (40–190 keV) in a patient with hypovascularized liver metastases of pleura mesothelioma. Hypovascularized metastasis in segment VI (arrow).

Protocol

Detail

Value

Scanner (PCCT)

NAEOTOM Alpha

Scanner (EID-CT)

SOMATOM AS20

Application

Contrast-enhanced abdominal oncologic CT; hypovascularized liver metastases

Study population

100 patients with liver metastases: PCCT n = 50, EID-CT n = 50

PCCT acquisition mode

QuantumPlus with spectral information

Detector energy thresholds

20, 35, 65, 70 keV

Scan direction

Craniocaudal

Patient position

Supine

Scan range

Diaphragm or upper thoracic aperture to symphysis

Breath-hold

Single breath-hold

Tube voltage (PCCT)

120 kVp

Tube current modulation

CARE Dose4D

IQ level

145

Rotation time

0.25 s

Pitch

0.8

Collimation

144 × 0.4 mm

Reconstruction kernel

Qr40

Iterative reconstruction

QIR 3

Slice thickness

1.0 mm

Reconstruction increment

1.0 mm

Spectral postprocessing

SPP spectral series

VMI levels

40, 45, 50, 55, 60, 70, 80, 90, 100, 110, 130, 150, 170, 190 keV

Contrast agent

Iopromide (Ultravist 300 mg I/mL)

Contrast volume

120 mL

Saline chaser

30 mL

Flow rate

4.0 mL/s

Bolus triggering

120 HU in ascending aorta

Post-trigger delay

45 s

EID-CT tube voltage

Auto-kV; 100 kVp in 46 patients, 120 kVp in 4 patients

EID-CT rotation time

0.5 s

EID-CT pitch

1.05

EID-CT collimation

1.5 × 16 × 1.2 mm

EID-CT reconstruction

I31f, SAFIRE level 3

Primary endpoints

Image noise, tumor-to-liver ratio (TLR), contrast-to-noise ratio (CNR), BMI-dependent performance

Key Results

Parameter

Main finding

Optimal lesion conspicuity

Greatest at low-keV VMI; TLR was lowest at 40 keV (0.37)

CNR

Maximum at the low end of the spectrum: 6.88; CNR was significantly higher at ≤70 keV than >70 keV

Image noise

At 70 keV, PCCT had lower noise than EID-CT: 15.4 vs. 17.1 HU

70-keV comparison

TLR and CNR were broadly comparable between PCCT and EID-CT

<70-keV advantage

PCCT provided higher CNR and greater lesion conspicuity than EID-CT

BMI effect

At 70 keV, PCCT maintained similar noise in high- vs. low-BMI patients (15.8 vs. 15.3 HU)

Dose/BMI relationship

CTDI increased with BMI on both systems, but the increase was more pronounced with EID-CT

Main implication

Spectral PCCT allows low-keV VMI to increase iodine contrast and improve visualization of hypovascularized liver metastases while maintaining favorable noise characteristics, with a particular advantage in larger patients.

Source:
Bette S, Decker JA, Braun FM, Becker J, Haerting M, Haeckel T, Gebhard M, Risch F, Woźnicki P, Scheurig-Muenkler C, Kroencke TJ, Schwarz F. Optimal Conspicuity of Liver Metastases in Virtual Monochromatic Imaging Reconstructions on a Novel Photon-Counting Detector CT—Effect of keV Settings and BMI. Diagnostics. 2022;12(5):1231. doi:10.3390/diagnostics12051231.

]]> (2025) Becker | Spectral PCCT differentiates hyperdense vascular from non-vascular renal lesions https://connect.siemens-healthineers.com/ja/discussion/467/2025-becker-spectral-pcct-differentiates-hyperdense-vascular-from-non-vascular-renal-lesions Sat, 08 Aug 2026 06:28:57 +0000 Publication protocols Daniel Stromer 467@/ja/discussions

This pilot study demonstrates that spectral information from photon-counting detector CT (PCD-CT) can help differentiate hyperdense renal cysts from vascular renal lesions when conventional portal-venous images are indeterminate. In 26 patients with 42 hyperdense renal lesions, attenuation on standard 70-keV VMI substantially overlapped between vascular and non-vascular lesions.

Iodine quantification maps provided the strongest differentiation: non-vascular lesions measured 5.7 ± 7.8 HU versus 33.3 ± 19.0 HU for vascular lesions. A threshold of >20.3 HU identified vascular lesions with 87.5% sensitivity and 88.2% specificity, correctly identifying 7/8 vascular lesions.

VNC was less specific: a 52-HU threshold achieved 100% sensitivity but only 55.9% specificity. The results suggest that routinely available spectral PCD-CT data—particularly iodine maps—could potentially reduce additional true non-contrast or multiphasic imaging when an incidental hyperdense renal lesion is encountered, although validation in larger cohorts is required.

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Figure 3. (A): Axial 70 keV reconstruction as well as VNC and iodine maps of a left renal mass in a portal venous CT scan of the abdomen. The lesion shows elevated HU in 70 keV (75 HU), VNC values of 66 HU (B) and 13 HU for iodine map CT values (C). (D,E): Contrast-enhanced ultrasound confirmed that there was no contrast medium uptake. (F–H): Example of a renal mass without solid components and elevated CT values in iodine maps in comparison to the first patient (52 HU) and similar values in 70 keV reconstructions (86 HU) compared to the confirmed renal cyst (A). Contrast-enhanced ultrasound confirmed a contrast enhancement (green arrow in (I,J)) and histopathology revealed the diagnosis of a renal cell carcinoma.

Protocol

Detail

Value

Scanner

NAEOTOM Alpha

Application

Contrast-enhanced abdominal CT / characterization of hyperdense renal lesions

Study population

26 patients, 42 hyperdense renal lesions (>20 HU)

Acquisition mode

QuantumPlus with spectral information

Scan phase

Portal venous phase

Scan area

Lung apex or diaphragm to symphysis

Scan direction

Craniocaudal

Patient position

Supine

Breath-hold

Single breath-hold

Tube voltage

120 kVp

Tube current modulation

CARE Dose4D

Rotation time

0.25 s

Pitch

0.8

Collimation

144 × 0.4 mm

Slice thickness

1.0 mm

Reconstruction increment

1.0 mm

Reconstruction kernel

Qr40

Iterative reconstruction

QIR 3

Spectral postprocessing

SPP

VMI

70 keV

Spectral reconstructions

VNC and iodine quantification maps

Workstation

Syngo.Via VB60A

Contrast agent

Iopromide (Ultravist 300 mgI/mL)

Contrast volume

120 mL

Saline chaser

30 mL

Flow rate

4.0 mL/s

Bolus triggering

120 HU in ascending aorta

Post-trigger delay

45 s

Image analysis

Three ROI measurements per renal lesion; mean value used

Reference standard

TNC CT, ultrasound/CEUS, MRI/PET-CT, or histopathology

Key Results

Parameter

Main finding

Study cohort

26 patients with 42 hyperdense renal lesions

70-keV VMI

Substantial overlap between non-vascular (61.4 ± 19.4 HU) and vascular lesions (65.5 ± 17.4 HU); p = 1.000

Iodine maps

Non-vascular 5.7 ± 7.8 HU vs vascular 33.3 ± 19.0 HU; p = 0.002

Iodine-map threshold

>20.3 HU

Iodine-map performance

87.5% sensitivity, 88.2% specificity

Vascular lesions detected

7/8 (87.5%)

VNC values

Non-vascular 55.7 ± 24.2 HU vs vascular 32.2 ± 11.1 HU; p = 0.034

VNC threshold

52 HU

VNC performance

100% sensitivity, 55.9% specificity

70-keV threshold

74 HU

70-keV performance

76.5% sensitivity, 50% specificity

Best spectral feature

Iodine quantification maps were the most important discriminator in random-forest feature selection

Potential implication

Spectral iodine information from routine PCD-CT may reduce the need for additional TNC or follow-up examinations in indeterminate hyperdense renal lesions, pending validation in larger studies

Source:
Becker J, Feitelson L-M, Risch F, Canalini L, Kaufmann D, Wudy R, Jehs B, Haerting M, Wollny C, Scheurig-Muenkler C, et al. Spectral Differentiation of Hyperdense Non-Vascular and Vascular Renal Lesions Without Solid Components in Contrast-Enhanced Photon-Counting Detector CT Scans—A Pilot Study. Diagnostics. 2025;15(1):79. https://doi.org/10.3390/diagnostics15010079

]]> (2025) Dane | Follow-up recommendation rates with abdominopelvic PCCT vs EID dual/single energy https://connect.siemens-healthineers.com/ja/discussion/463/2025-dane-follow-up-recommendation-rates-with-abdominopelvic-pcct-vs-eid-dual-single-energy Fri, 07 Aug 2026 05:27:24 +0000 Scientific publications Daniel Stromer 463@/ja/discussions Access publications

Key takeaways

For a cohort of 16,065 patients, PCCT significantly reduced follow-up imaging recommendations after contrast-enhanced abdominopelvic CT compared with conventional single-energy CT (SECT), with recommendation rates of 8.1% (PCCT), 8.7 (DECT) and 13.5% (SECT).


Compared with SECT, PCCT substantially decreased recommendations for MRI (5.2% vs. 6.4%), CT (2.0% vs. 5.0%), and ultrasound (1.4% vs. 2.7%), reflecting greater diagnostic confidence and reducing unnecessary downstream imaging.


The lower follow-up imaging rate translated into projected healthcare savings of nearly USD 115,000, highlighting the potential of PCCT to improve diagnostic efficiency while reducing healthcare costs.


Source: Dane B, Attlassy Y, Ihionkhan E, et al. Abdominal Radiology. 2026;51:3681–3689. doi:10.1007/s00261-025-05343-7.

]]> (2026) Yokoyama | Practical strategies to maximize the clinical impact of PCCT in abdominal imaging https://connect.siemens-healthineers.com/ja/discussion/442/2026-yokoyama-practical-strategies-to-maximize-the-clinical-impact-of-pcct-in-abdominal-imaging Wed, 15 Jul 2026 11:31:19 +0000 Publication protocols Daniel Stromer 442@/ja/discussions Note: This abdominal imaging deep dive paper does not specify scan protocols, but give an overview on clinical practice.

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Figure 2. Early-stage pancreatic cancer was evaluated using a photon-counting detector CT. A 57-year-old female patient with suspected early-stage pancreatic cancer based on focal pancreatic atrophy on magnetic resonance cholangiopancreatography underwent dynamic contrast-enhanced PCD-CT. In the arterial phase, 70 keV VMI (a) demonstrates focal atrophy and a subtle hypoattenuating area in the pancreatic tail. The lesion remains inconspicuous on 40 keV VMI (b), making its identification as a hypovascular tumor confidently challenging. In the equilibrium phase, faint delayed improvement is suspected on 70 keV VMI (c), which becomes more conspicuous on 40 keV VMI (d) (yellow arrows). Cinematic volume-rendered images reconstructed from arterial-phase 40 keV VMI data (e, f) clearly depict focal atrophy of the pancreatic tail (arrowheads). Detecting early-stage pancreatic cancer may be challenging in the arterial phase; therefore, findings, including focal parenchymal atrophy and delayed enhancement, are important. PCD-CT is particularly advantageous for detecting these subtle features

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Partially AI-generated overview

UHR PCCT in abdominal imaging

  • UHR PCCT enables slice thicknesses down to 0.2 mm, improving visualization of small vessels, pancreatic ducts, urinary calculi, and other fine anatomical structures while reducing blooming artifacts.
  • The greatest clinical benefit is seen in CT angiography, interventional planning, urinary stone detection, and evaluation of calcified or high-contrast structures, whereas improvements for low-contrast abdominal lesions remain more limited.
  • A dual-reconstruction workflow is recommended, using standard-resolution images for routine interpretation and targeted UHR reconstructions for problem-solving applications requiring maximum spatial detail (see reconstruction).

Spectral imaging

  • Spectral imaging is inherently available in every PCCT examination with specific scan modes, enabling retrospective reconstruction of virtual monoenergetic images (VMIs), iodine maps, and material decomposition without dedicated dual-energy acquisition.
  • Low-keV VMIs (40–50 keV) substantially enhance iodine contrast, improving visualization of hypervascular and hypovascular lesions, while 70 keV closely resembles conventional CT and serves as the preferred routine reconstruction.
  • Spectral imaging also supports virtual non-contrast (VNC) imaging, quantitative iodine mapping, and contrast-media reduction strategies while maintaining diagnostic image quality.

Clinical impact of spectral imaging

  • Low-keV VMIs improve detection and characterization of pancreatic cancer, liver metastases, rectal cancer, inflammatory diseases, and vascular abnormalities by increasing lesion conspicuity and tissue contrast.
  • Quantitative iodine density maps provide functional information that may serve as imaging biomarkers for tumor perfusion, treatment response, inflammatory activity, and lymph node assessment.
  • The combination of high-resolution anatomical imaging and routine spectral information supports the concept of "one-stop imaging", potentially reducing additional CT or MRI examinations in selected clinical scenarios.

Reconstruction strategies and optimization

  • 70-keV VMI with medium-soft kernels is recommended for routine abdominal interpretation because it closely matches conventional CT while preserving access to spectral information.
  • Task-specific reconstructions using 40–50 keV VMIs, sharper kernels, thinner slices, and higher Quantum Iterative Reconstruction (QIR) levels improve lesion conspicuity and vascular visualization when clinically indicated.
  • Optimizing kernel selection, slice thickness, matrix size, and QIR is essential to balance spatial resolution, image noise, and diagnostic confidence for different abdominal imaging tasks.
    "Accordingly, dual reconstruction is common in clinical practice. A routine reconstruction consisting of 70-keV VMI, a medium-smooth vascular kernel (Br40–44 or Bv36), moderate QIR (QIR-2 or 3), and a slice thickness of ~0.6 mm provide stable texture and noise control for routine interpretation. Additional task-specific reconstructions may employ lower-keV VMIs (e.g., 40 keV), sharper kernels (Bv72), higher QIR (QIR-4), thinner slices (~0.2 mm), and larger matrices (e.g., 1024, 2048) for problem-solving or high-resolution evaluation."
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Implementation considerations: data management and infrastructure

  • Routine PCCT generates substantially larger datasets than conventional CT due to thin-slice acquisitions, high-resolution matrices, and multiple spectral reconstructions, requiring significantly greater storage and computational resources.
  • Successful implementation requires optimized PACS infrastructure, selective archiving strategies, network capacity, and efficient spectral data management to prevent workflow bottlenecks.
  • Institutions should view PCCT implementation as a system-wide workflow transformation, rather than simply replacing an existing CT scanner.

Future perspectives

  • Future multi-energy PCCT systems are expected to expand quantitative imaging through improved material decomposition, electron density mapping, extracellular volume (ECV) assessment, and K-edge imaging.
  • Emerging applications include molecular imaging, virtual non-calcium imaging, automated tissue characterization, and AI-assisted quantitative biomarkers, extending CT beyond morphology-based diagnosis.
  • Wider adoption will depend on demonstrating clinical value, cost-effectiveness, multivendor standardization, and robust quantitative reproducibility across different PCCT platforms.

Source: Yokoyama K, Kawasaki Y, Fujii M, et al. Abdominal Radiology. 2026.

]]> (2025) Braaksma | Pediatric abdomen PCCT protocol development https://connect.siemens-healthineers.com/ja/discussion/350/2025-braaksma-pediatric-abdomen-pcct-protocol-development Fri, 10 Apr 2026 14:19:13 +0000 Publication protocols Daniel Stromer 350@/ja/discussions

For routine pediatric abdomen PCCT, start with Quantum mode at 70 kV and low-keV VMI rather than defaulting to QuantumPlus. Based on their phantom work, the authors favor the lowest tube voltage as the ALARA-oriented starting point, and for their standard protocol they selected 70 kV Quantum mode with VMI 53 keV.


Optimize image quality first through reconstruction settings before increasing acquisition dose. The authors recommend first adjusting QIR strength, kernel choice, and windowing if noise is too high, and only then considering higher IQ level, DAC changes, or QuantumPlus mode.


Use high-pitch FLASH selectively, not routinely. The authors found FLASH shortened scan time but slightly increased noise and dose, so they recommend it mainly for children who cannot hold their breath long enough for a standard scan.

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Figure 5. Examples of the clinical implementation of the pediatric abdomen protocol. Axial computed tomography slices in the portal venous phase after intravenous contrast demonstrate the appearances of contrast and noise of the protocol at different ages. Protocol: 70 kV Quantum mode at 53 keV virtual monoenergetic image, IQ level 120, body reconstruction kernel 40, quantum iterative reconstruction 2, 1.0-mm slice thickness. a Six-month-old girl after liver transplantation. b Two-year-old girl prior to liver transplantation. c Six-year-old boy after liver transplantation

Source note for image: Braaksma et al., Pediatric Radiology, 2025.

Standard Protocol

Parameter

Scanner

NAEOTOM Alpha

Scan mode

Quantum

Siemens protocol

RoutineFlashSpiralChildAbdomenQuantum

Tube voltage, kV

70/90

Number of slices, mm

144 × 0.4

Z-coverage, mm

58

Rotation time, s

0.25

IQ level

120

Pitch

3.2 (FLASH) or 1.5

Care keV

On

CARE Dose4D

On

Dose adaption curve

Average

Tissue of interest setting

Soft tissue with contrast

Reconstruction parameters

Reconstructed slice thickness, mm

1.0 and 3.0 (0.6 and 2.0 increment)

Matrix

Auto

VMI, keV

53

Kernels

Br40 (1 mm), Br40 (3 mm)

QIR

2

Window level / window width

55 / 335

Spectral analysis

No

Intravenous iodine contrast

Contrast phase

Portal venous, delay is age dependent

Volume and flow rate

Age and kV dependent

Complex Protocol (not used clinically, optimized for noise & thinner slices)

Parameter

Value

Scanner

NAEOTOM Alpha

Scan mode

QuantumPlus

Siemens protocol

RoutineFlashSpiralChildAbdomenQuantumplus

Tube voltage, kV

120/140

Number of slices, mm

144 × 0.4

Z-coverage, mm

58

Rotation time, s

0.25

IQ level

120

Pitch

3.2 (FLASH) or 1.5

Care keV

On

CARE Dose4D

On

Dose adaption curve

Average

Tissue of interest setting

Soft tissue with contrast

Reconstruction parameters

Reconstructed slice thickness, mm

0.4, 1.0 and 3.0 (0.3, 0.6 and 2.0 increment)

Matrix

Auto

VMI, keV

53 (T3D for non-contrast if needed)

Kernels

Br40 (1 mm), Br40 (3 mm), Bv60 (0.4, 1 mm)

QIR

2

Window level / window width

55 / 335

Spectral analysis

Iodine map, virtual non-contrast

Intravenous iodine contrast

Contrast phase

Portal venous, delay is age dependent

Volume and flow rate

Age and kV dependent

Full citation:
Braaksma J, Greuter MJW, Verhagen MV. Physics and rationale in pediatric abdomen photon counting detector computed tomography: an investigative review towards development of a pediatric abdomen protocol. Pediatr Radiol. 2025;55:1556–1567. doi:10.1007/s00247-025-06274-7

]]> (2024) Tóth | Iodine quantification differentiates renal cysts vs tumors on PCCT https://connect.siemens-healthineers.com/ja/discussion/345/2024-toth-iodine-quantification-differentiates-renal-cysts-vs-tumors-on-pcct Fri, 10 Apr 2026 11:54:14 +0000 Publication protocols Daniel Stromer 345@/ja/discussions

Automated iodine maps on PCCT showed strong diagnostic performance to differentiate renal cysts from neoplasms, with AUC up to 0.99.

Renal cysts consistently demonstrated near-zero iodine concentration, while neoplasms showed higher and more heterogeneous iodine values.

Minimum iodine concentration in suspicious regions was particularly powerful, nearly perfectly separating benign vs malignant lesions.

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Figure 2. (a) A 86-year-old female who presented with abdominal pain. Reconstructed iodine quantification map of the axial CT image shows the left kidney with renal cyst. For homogeneous lesions, one ROI was placed in the interior of the renal lesion, as large as possible to cover the entire lesion (yellow arrow pointing to the ROI shown as yellow circle). (b) A 64-year-old female presented for RCC staging. A reconstructed iodine quantification map of the axial CT image shows the right kidney with renal neoplasm. For heterogeneous lesions, after the placement of the first ROI (yellow arrow pointing to the ROI shown as yellow circle), a secondary ROI (yellow star marking the ROI shown as yellow circle) was placed on the area of the highest conspicuity of iodine concentration. (CT: Computed tomography, RCC: Renal cell carcinoma, ROI: Region of interest).

Source: Tóth et al., Journal of Clinical Imaging Science, 2024

Protocol

Detail

Value

Scanner

NAEOTOM Alpha

Scan area

Abdomen

Scan mode

QuantumPlus

Tube voltage [kV]

120

Effective mAs [mAs]

184.9 ± 77.3

IQ level

249

Dose modulation

CARE Dose4D

CTDIvol [mGy]

15.2 ± 6.6

DLP [mGy*cm]

1020.5 ± 608.0

Rotation time [s]

0.5

Pitch

0.8

Matrix

512 × 512

Slice collimation [mm]

144 × 3

Slice width [mm]

3

keV level [keV]

n.a.

Contrast agent

Omnipaque 350 mgI/mL

Contrast volume

1.25 ± 0.13 mL/kg

Flow rate

2.96 ± 0.59 mL/s

Tóth A, Chamberlin JH, Mendez S, Varga-Szemes A, Hardie AD. Iodine quantification of renal lesions: Preliminary results using spectral-based material extraction on photon-counting CT. J Clin Imaging Sci. 2024;14:7. doi:10.25259/JCIS_1_2024

]]> (2024) Hoeijmakers | PCCT enables contrast media reduction in abdominal imaging https://connect.siemens-healthineers.com/ja/discussion/344/2024-hoeijmakers-pcct-enables-contrast-media-reduction-in-abdominal-imaging Fri, 10 Apr 2026 11:48:02 +0000 Publication protocols Daniel Stromer 344@/ja/discussions

PCCT reduced total iodine load by 20.1% for abdominal portal venous phase CT compared with an individualized kV-adapted EID-CT protocol, while maintaining diagnostic image quality.

Despite lower liver attenuation at the standard 60 keV reconstruction, PCCT achieved significantly higher SNR and CNR than EID-CT.

All scans on both systems were rated as diagnostically sufficient by both readers.

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Figure 3. Representative abdominal PVP scans from both a photon-counting detector CT (PCCT) and an energy-integrating detector CT (EID-CT), illustrating comparable image quality (IQ). Image A and B were rated as moderate and image D and E as good by both observers. Image C and F are the 55 keV reconstructions of image B and E respectively but were not assessed subjectively.

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Protocol

Detail

Value

Scanner

NAEOTOM Alpha

Scan mode

QuantumPlus

Tube voltage [kV]

120 kV

Rotation time [s]

0.25 for combined thorax/abdominal CT;

0.5 for abdominal CT only

Collimation

144 × 0.40 mm

IQ level

145

optimized for soft tissue with contrast

Tube current modulation

CARE Dose 4D

CTDIvol [mGy]

7.4 ± 2.2

Standard reconstruction

VMI at 60 keV

Secondary reconstruction

VMI at 55 keV from spectral post-processing

Slice thickness / increment

3 mm / 2 mm

Kernel

Br40

Iterative reconstruction

Level 3

SPP reconstruction thickness / increment

2 mm / 1.5 mm

SPP kernel

Qr40

Contrast agent

Ultravist 300 mgI/mL or Ultravist 370 mgI/mL

Injection access

18-, 20-, or 22-gauge needle

Scan timing

Approximately 70 s after injection

Contrast dosing factor

0.30 g I/kg

Injection duration

30 s

Protocol basis

TBW-adapted CM protocol tailored to VMI at 60 keV

Hoeijmakers EJI, Stammen L, Wildberger JE, et al. PCD-CT enables contrast media reduction in abdominal imaging compared to an individualized kV-adapted contrast media injection protocol on EID-CT. Eur J Radiol. 2024;179:111680.

]]> (2024) Woeltjen | Low-keV VMI improves conspicuity on PCCT for pancreatic cancer https://connect.siemens-healthineers.com/ja/discussion/343/2024-woeltjen-low-kev-vmi-improves-conspicuity-on-pcct-for-pancreatic-cancer Fri, 10 Apr 2026 11:38:49 +0000 Publication protocols Daniel Stromer 343@/ja/discussions

Mono40 keV images provided the best pancreatic ductal adenocarcinoma conspicuity on PCCT in both arterial and portal venous phases.

Quantitatively, tumor-parenchyma attenuation difference and CNR were highest at 40 keV and decreased stepwise with rising keV.

Readers still preferred polyenergetic images for overall image quality and lowest perceived noise, despite better lesion conspicuity on low-keV VMI.

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Figure 4. PCCT images of the pancreas with a superior mesenteric artery encasing PDAC in arterial (A–C) and portal venous (D–F) contrast phase. A and D are polyenergetic reconstructions. B and E are monoenergetic reconstructions at 40 keV. C and F are monoenergetic reconstructions at 70 keV.

Source: Woeltjen et al., European Journal of Radiology, 2024

Protocol

Detail

Value

Scanner

NAEOTOM Alpha

Scan mode

QuantumPlus

Tube voltage [kVp]

120–140

Slice collimation

144 × 0.4 mm

Tube current modulation

CARE Dose4D

IQ level

170

Pitch

0.8

Rotation time [s]

0.5

CTDIvol [mGy]

8.1 ± 2.5 mGy arterial

7.7 ± 1.9 mGy portal venous

Doselength product [mGy*cm]

209.8 ± 78.9 arterial

443.2 ± 149.5 portal venous

Contrast agent

ACCUPAQUE 300

Contrast dose

1 mL/kg

Injection flow

4 mL/s for initial diagnostic scans; 2.5 mL/s for follow-up venous-only scans

Bolus trigger

ROI in descending aorta, threshold 100

Arterial delay

7 s after threshold

Venous delay

60 s after threshold

Post-processing software

Syngo.Via VB60

VMI range

40–70 keV in 5 keV steps

Polyenergetic kernel

Br36

Spectral

40 keV images

VMI kernel

Qr36

Iterative reconstruction

Quantum iterative reconstruction Q4

Slice thickness / increment

1.0 mm / 0.6 mm

Woeltjen MM, Niehoff JH, Roggel R, et al. Pancreatic cancer in photon-counting CT: Low keV virtual monoenergetic images improve tumor conspicuity. Eur J Radiol. 2024;173:111374.

]]> (2023) Becker | Abdominal PCCT: general image quality and dose exposure https://connect.siemens-healthineers.com/ja/discussion/342/2023-becker-abdominal-pcct-general-image-quality-and-dose-exposure Fri, 10 Apr 2026 11:25:03 +0000 Publication protocols Daniel Stromer 342@/ja/discussions

In this first clinical routine experience, abdominal PCCT achieved superior overall image quality versus conventional CT, with higher Likert scores for general image quality, lower perceived noise, and fewer artifacts.

Objective image quality was also better with PCCT, with significantly higher SNR in fat, muscle, and air, but this came at the cost of higher radiation exposure in the initial manufacturer-default protocol.

In an ex vivo phantom study, the higher PCCT dose was accompanied by more DNA double-strand break foci than conventional CT, highlighting the need for protocol optimization before routine abdominal PCCT can be considered dose-efficient.

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Figure 3. Example of axial and coronal reconstruction of abdominal conventional CT (A and C) and PCCT (B and D) for the depiction of subjective image impression. DLP was 413.38 and 453.98 mGy*cm for PCCT and conventional CT, respectively. Both examinations were rated “very good” by all examiners (general image quality PCCT: 4.75 ± 0.5; general image quality conventional CT: 4.75 ± 0.5)

Source: Becker et al., European Radiology, 2023

Protocol

Detail

Value

Scanner

NAEOTOM Alpha

Exam type

QuantumPlus

Single-phase contrast-enhanced abdominal CT, portal venous phase

Tube voltage

120 kV

PCCT collimation

144 × 0.4 mm

Rotation time

0.5 s

Pitch

0.8

Reconstruction

Axial 1 mm Br40, coronal 3 mm Br40, sagittal 3 mm Br60

Reconstruction algorithm

QIR

mAs preset

IQ145

145 mAs at 120 kV

Mean Doselength product

DLP 419.2 ± 162.2 mGy·cm

Effective dose

5.00 ± 1.95 mSv

Becker BV, Kaatsch HL, Nestler K, et al. Initial experience on abdominal photon-counting computed tomography in clinical routine: general image quality and dose exposure. Eur Radiol. 2023;33:2461-2468.

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