Abdominal

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…

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…

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…

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…

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…

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…

This case report has been published in Radiology. Access publication 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)…

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…

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…

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-…

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)…

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…

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…

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…

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…

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…

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…

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…

Note: This abdominal imaging deep dive paper does not specify scan protocols, but give an overview on clinical practice. Access publication 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…

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…

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…

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…

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…

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,…