Thorax imaging
Numerous scientific studies have reported on the clinical impact of Quantum HD in the thorax. For example, in a retrospective study, 112 consecutive patients with stable Interstitial Lung Disease (ILD) received both a standard resolution EID-CT scan and a Quantum HD PCCT scan within a median interval time of 12.8 months [1].
The classification of 4 of these patients changed from nonfibrotic (on standard resolution EID-CT) to fibrotic (on PCCT using Quantum HD) based “on differences in the depiction of focal areas of traction bronchiolectasis between [standard resolution EID-CT] (missed as blurred) and Quantum HD (sharp delineation)”. Note that care was taken to ensure no differences were present due to an interim development of abnormalities. As an additional benefit, there was a mean dose reduction of 27% in the CTDI for the PCCT scan.
Another study reported an increased confidence in diagnosis of ILD using PCCT’s Quantum HD compared to standard resolution EID-CT as evidenced by a reduction in the number of intermediate determinations made [2]. Specifically, “Photon-counting detector CT demonstrated a decreased number of indeterminate ground-glass opacities (GGO) (17 vs 26), an increased number of unlikely GGO (74 vs 50), and an increased number of likely reticulations (140 vs 130) relative to EID-CT.”
Similarly, findings missed by resolution typical of conventional EID-CT, were discovered in a prospective study of COVID-19 patients using Quantum HD [3]. Patients were scanned using both types of CT on the same day and half of the patients showed some type of additional lung abnormality on Quantum HD. In particular, “non-specific GGO on EID CT images revealed to include fine reticulations, a possible sign of incipient pulmonary fibrosis, on Quantum HD scans in 6/20 (30%) participants.”
Figure 1 and Figure 2 show examples of Quantum HD applied to the lung.
Figure 1: Comparison of standard resolution using 1 mm slice thickness on conventional CT (Fig. 1a), same slice thickness on NAEOTOM Alpha (Fig. 1b) and Quantum HD (Fig. 1c). Courtesy of Erasmus Medical Center Rotterdam, Rotterdam, Netherlands.
Figure 2: Extensive interstitial lung disease. T3D | 0.2 mm | Bl64 | Sn 140 kV | CTDIvol: 2.27 mGy. Courtesy of Erasmus Medical Center Rotterdam, Rotterdam, Netherlands.