Left and right ventricle assessment with Cardiac CT: validation study vs. Cardiac MR

Objectives To compare Magnetic Resonance (MR) and Computed Tomography (CT) for the assessment of left (LV) and right (RV) ventricular functional parameters. Methods Seventy nine patients underwent both Cardiac CT and Cardiac MR. Images were acquired using short axis (SAX) reconstructions for CT and 2D cine b-SSFP (balanced- steady state free precession) SAX sequence for MR, and evaluated using dedicated software. Results CT and MR images showed good agreement: LV EF (Ejection Fraction) (52±14% for CT vs. 52±14% for MR; r0 0.73; p>0.05); RV EF (47±12% for CT vs. 47±12% for MR; r00.74; p>0.05); LV EDV (End Diastolic Volume) (74± 21 ml/m 2 for CT vs. 76±25 ml/m 2 for MR; r00.59; p>0.05); RV EDV (84±25 ml/m 2 for CT vs. 80±23 ml/m 2 for MR; r0 0.58; p>0.05); LV ESV (End Systolic Volume)(37±19 ml/m 2 for CT vs. 38±23 ml/m 2 for MR; r00.76; p>0.05); RV ESV (46±21 ml/m 2 for CT vs. 43±18 ml/m 2 for MR; r00.70; p>0.05). Intra- and inter-observer variability were good, and the performance of CT was maintained for different EF subgroups. Conclusions Cardiac CT provides accurate and reproducible LVand RV volume parameters compared with MR, and can be considered as a reliable alternative for patients who are not suitable to undergo MR. Key Points • Cardiac-CT is able to provide Left and Right Ventricular function. • Cardiac-CT is accurate as MR for LV and RV volume assessment. • Cardiac-CT can provide accurate evaluation of coronary arteries and LV and RV function

Virtual mono-energetic images and iterative image reconstruction: abdominal vessel imaging in the era of spectral detector CT

AIM: To compare the quality of virtual mono-energetic (VMI) and polychromatic images reconstructed with hybrid iterative (PCIHIR) or model-based reconstruction (PCIMBR) derived from dual-layer spectral detector computed tomography (SDCT) in arterial phase images to visualise the aorta and abdominal main branches. MATERIAL AND METHODS: A retrospective review of 50 patients with abdominal arterial phase scans was undertaken. Attenuation, intraluminal noise, and signal-/contrast-to-noise ratio (S-/CNR) were assessed in the PCIHIR, PCIMBR and VMI40keV, VMI70keV, and VMI100keV images. Contrast, noise, and visualization of soft-plaque, and macro-/micro-calcifications were scored in a blinded reading by two radiologists. RESULTS: VMI40keV yielded highest S-/CNR (p = 0.999) and yielded higher SNR than PCIHIR. VMI70keV yielded higher CNR than PCIHIR (p0.999), while VMI40keV scored second best for depiction of soft-plaque (p<0.020). CONCLUSIONS: VMI40keV and VMI70keV yield better S-/CNR than PCIHIR and PCIMBR; however, PCIMBR visualized arteriosclerotic plaques best, followed by VMI40keV for depiction of soft-plaque and VMI100keV for macro- and micro-calcification. Based on the present findings, PCIMBR on conventional CT and VMI40keV supplemented by VMI100keV on SDCT are recommended for the diagnostic assessment of abdominal arteries. (C) 2020 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved

Head and neck squamous cell carcinoma: evaluation of iodine overlay maps and low-energy virtual mono-energetic images acquired with spectral detector CT

AIM: To evaluate the diagnostic value of spectral detector computed tomography (SDCT)-derived iodine overlay maps and low-energy virtual mono-energetic images (VMI) for the initial locoregional assessment of primary, therapy-naive head and neck cancer. MATERIALS AND METHODS: Fifty-six patients with histologically confirmed untreated squamous cell carcinoma of the head and neck who underwent SDCT of the neck for staging purposes were included in this retrospective study. Attenuation, image noise as well as signal-and contrast-to-noise ratios (S-/CNR) in VMI40-70keV were obtained from region of interest (ROI)-based measurements in the tumour and important anatomical landmarks (sternocleidomastoid muscle, subcutaneous fat, thyroid gland, submandibular gland, carotid artery, and jugular vein). Tumour conspicuity and delineation, as well as subjective image quality, were rated for conventional images, VMI40-70keV, and iodine overlay maps using five-point Likert scales. RESULTS: The CNR of the tumour versus the floor of the mouth and the CNR of the tumour versus the sternocleidomastoid muscle was significantly higher in VMI40keV in comparison to conventional images (10.0 f 7.3 versus 3.8 f 3.3 and 11.3 f 7.6 versus 3.6 f 2.8; p<0.05 each). This was supported by qualitative results, as tumour conspicuity and delineation received superior ratings in iodine overlay maps and VMI40keV compared to conventional images (5 [3-5] and 5 [4-5] versus 3 [2-5]; 5 [2-5] and 5 [3-5] versus 3 [2-4], respectively, all p<0.05). VMI40keV yielded the highest score among all included image reconstructions for overall image quality (p<0.05 all). CONCLUSION: Iodine overlay maps and low-energy VMI derived from SDCT improve initial assessment of primary squamous cell carcinoma of the head and neck compared to conventional images. (c) 2022 Published by Elsevier Ltd on behalf of The Royal College of Radiologists

Correlation of CT-data derived from multiparametric dual-layer CT-maps with immunohistochemical biomarkers in invasive breast carcinomas

Objective: To examine the correlation of quantitative measurements from material decomposition maps calculated from dual-layer CT (DLCT)-image datasets with immunohistochemical biomarkers of invasive breast carcinomas. Material and Methods: All patients at the University Breast Cancer Center who underwent a clinically indicated dual-layer CT-scan for staging of invasive ductal breast carcinoma from 01/2016 to 07/2020 were prospectively included. Iodine concentration maps and maps of the effective atomic numbers (Zeffective) were reconstructed from the image datasets. ROI-based evaluations of the index tumors and predefined references tissues for normalization were performed semi-automatically in identical anatomical positions using dedicated evaluation software. Statistical analysis was essentially descriptive using Spearmans rank correlation and (multivariable) partial correlation. Results: Bivariate showed statistically significant correlations of iodine contents (r = -0.154/-0.202/0.180, p = 0.039/0.006/0.015), and Zeffective-values (r = -0.158/-0.199/0.179, p = 0.034/0.007/0.016) for all 184 carcinomas and the subgroup of 168 invasive ductal carcinomas. The results were confirmed by multivariate analyses with age, diameter and ACR-grade as possible confounders. Normalization of the measured target values with those in the aorta confirmed significant correlations of iodine content and Zeffective compared to Estrogen (r = 0.174, p = 0.019), Progesteron (r = 0.168/0.177, p = 0.024/0.017), and HER2 receptor expression (r = -0.222/-0.184, p = 0.003/0.013). All CT-parameters showed significant correlations with immunohistochemical subtyping (r = 0.191/0.192, p = 0.010). Conclusions: Our preliminary results indicate that iodine content and Zeffective-values derived from DLCT-examinations correlate with hormone receptor expression in invasive breast carcinomas. Assignments to benign entities already seam feasible in clinical routine CT-diagnostics. After further investigations iodine content and Zeffective may be translated as diagnostical and prognostical biomarkers into clinical routine in the long term

Primary renal sarcomas: imaging features and discrimination from non-sarcoma renal tumors

Objectives: To assess imaging features of primary renal sarcomas in order to better discriminate them from non-sarcoma renal tumors. Methods: Adult patients diagnosed with renal sarcomas from 1995 to 2018 were included from 11 European tertiary referral centers (Germany, Belgium, Turkey). Renal sarcomas were 1:4 compared to patients with non-sarcoma renal tumors. CT/MRI findings were assessed using 21 predefined imaging features. A random forest model was trained to predict “renal sarcoma vs. non-sarcoma renal tumors” based on demographics and imaging features. Results: n = 34 renal sarcomas were included and compared to n = 136 non-sarcoma renal tumors. Renal sarcomas manifested in younger patients (median 55 vs. 67 years, p < 0.01) and were more complex (high RENAL score complexity 79.4% vs. 25.7%, p < 0.01). Renal sarcomas were larger (median diameter 108 vs. 43 mm, p < 0.01) with irregular shape and ill-defined margins, and more frequently demonstrated invasion of the renal vein or inferior vena cava, tumor necrosis, direct invasion of adjacent organs, and contact to renal artery or vein, compared to non-sarcoma renal tumors (p < 0.05, each). The random forest algorithm yielded a median AUC = 93.8% to predict renal sarcoma histology, with sensitivity, specificity, and positive predictive value of 90.4%, 76.5%, and 93.9%, respectively. Tumor diameter and RENAL score were the most relevant imaging features for renal sarcoma identification. Conclusion: Renal sarcomas are rare tumors commonly manifesting as large masses in young patients. A random forest model using demographics and imaging features shows good diagnostic accuracy for discrimination of renal sarcomas from non-sarcoma renal tumors, which might aid in clinical decision-making. Key Points: • Renal sarcomas commonly manifest in younger patients as large, complex renal masses. • Compared to non-sarcoma renal tumors, renal sarcomas more frequently demonstrated invasion of the renal vein or inferior vena cava, tumor necrosis, direct invasion of adjacent organs, and contact to renal artery or vein. • Using demographics and standardized imaging features, a random forest showed excellent diagnostic performance for discrimination of sarcoma vs. non-sarcoma renal tumors (AUC = 93.8%, sensitivity = 90.4%, specificity = 76.5%, and PPV = 93.9%)

ALK(G1269A) mutation as a potential mechanism of acquired resistance to crizotinib in an ALK-rearranged inflammatory myofibroblastic tumor

Inflammatory myofibroblastic tumors are rare mesenchymal neoplasms frequently harboring oncogenic chromosomal rearrangements, most commonly, involving the ALK (anaplastic lymphoma kinase) gene. Treatment of this molecularly defined subgroup with the anaplastic lymphoma kinase inhibitor crizotinib has shown to be effective. However, comparable to lung adenocarcinoma, resistance inevitably develops. Second generation anaplastic lymphoma kinase inhibitors such as ceritinib are able to overcome acquired resistance to crizotinib. Here, we report the case of a patient with an inflammatory myofibroblastic tumors harboring a DCTN1-ALK fusion who developed resistance to crizotinib treatment. Next-generation sequencing of a rebiopsy sample revealed the acquisition of the ALK(G1269A) mutation as a mechanism of resistance. Therapy with ceritinib resulted in a short but profound clinical, metabolic and morphologic response. This case illustrates that (i) different tumor entities may share similar oncogenic driver mechanisms, rendering them vulnerable for the same therapeutic substances and (ii) likewise, the same mode of resistance may occur under targeted therapy among different tumor entities