Evaluation of hyperdense renal lesions incidentally detected on single-phase post-contrast CT using dual-energy CT

Objectives: When iodinated contrast is administered during CT simulation, standard practice requires a separate non-contrast CT for dose calculation. The objective of this study is to validate our hypothesis that since iodine affects Hounsfield units (HUs) more than electron density (ED), the information from post-contrast dual-layer CT (DLCT) would be sufficient for accurate dose calculation for both photon and proton therapy. Methods and materials: 10 pediatric patients with abdominal tumors underwent DLCT scans before and after iodinated contrast administration for radiotherapy planning. Dose distributions with these DLCT-based methods were compared to those with conventional calibration-curve methods that map HU images to ED and stopping-power ratio (SPR) images. Results: For photon plans, conventional and DLCT approaches based on post-contrast scans underestimated the PTV D99 by 0.87 ± 0.70% (p = 0.18) and 0.36 ± 0.31% (p = 0.34), respectively, comparing to their non-contrast optimization plans. Renal iodine concentration was weakly associated with D99 deviation for both conventional (R2 = 0.10) and DLCT (R2 = 0.02) approaches. For proton plans, the clinical target volume D99 errors were 3.67 ± 2.43% (p = 0.0001) and 0.30 ± 0.25% (p = 0.40) for conventional and DLCT approaches, respectively. The proton beam range changed noticeably with the conventional approach. Renal iodine concentration was highly associated with D99 deviation for the conventional approach (R2 = 0.83) but not for DLCT (R2 = 0.007). Conclusion: Conventional CT with iodine contrast resulted in a large dosimetric error for proton therapy, compared to true non-contrast plans, but the error was less for photon therapy. These errors can be greatly reduced in the case of the proton plans if DLCT is used, raising the possibility of using only a single post-contrast CT for radiotherapy dose calculation, thus reducing the time and imaging dose required. Advances in knowledge: This study is the first to compare directly the differences in the calculated dose distributions between pre- and post-contrast CT images generated by single-energy CT and dual-energy CT methods for photon and proton therapy.

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Characterization of Small Focal Renal Lesions: Diagnostic Accuracy with Single-Phase Contrast-enhanced Dual-Energy CT with Material Attenuation Analysis Compared with Conventional Attenuation Measurements

Radiology ◽

10.1148/radiol.2017161872 ◽

2017 ◽

Vol 284 (3) ◽

pp. 737-747 ◽

Cited By ~ 39

Author(s):

Daniele Marin ◽

Drew Davis ◽

Kingshuk Roy Choudhury ◽

Bhavik Patel ◽

Rajan T. Gupta ◽

...

Keyword(s):

Diagnostic Accuracy ◽

Phase Contrast ◽

Single Phase ◽

Dual Energy ◽

Dual Energy Ct ◽

Renal Lesions ◽

Contrast Enhanced

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Side-by-side evaluation of virtual non-contrast and post-contrast images improves detection of clinically significant urolithiasis on single-phase split bolus dual-energy CT urography

British Journal of Radiology ◽

10.1259/bjr.20210013 ◽

2021 ◽

Vol 94 (1121) ◽

pp. 20210013

Author(s):

Doris Dodig ◽

Tereza Solocki Matić ◽

Iva Žuža ◽

Ivan Pavlović ◽

Damir Miletić ◽

...

Keyword(s):

Dose Reduction ◽

Single Phase ◽

Dual Energy ◽

Detection Sensitivity ◽

Urinary Stones ◽

Dual Energy Ct ◽

Ct Urography ◽

Post Contrast ◽

Clinically Significant ◽

Stone Detection

Objectives: Studies show insufficient sensitivity of virtual non-contrast (VNC) reconstructions for stone detection in dual-energy CT urography (DE-CTU). The aim of this study was to investigate if side-by-side-evaluation of both VNC and post-contrast images could increase the sensitivity of single-phase split bolus DE-CTU. Methods: Consecutive patients with haematuria who underwent split bolus DE-CTU on the same dual-source DE-CT scanner were retrospectively enrolled in the study. Intravenous furosemide and oral hydration were employed. Two readers, independently and then jointly in two separate sessions, recorded the location and the longest axial stone diameter on three randomised sets of images: separate VNC and post-contrast images, and side-by-side-reconstructions. True non-contrast (TNC) images served as the standard of reference. Results: A total of 83 urinary stones were detected on TNC images. Independent reader side-by-side-evaluation of VNC and post-contrast images yielded higher stone detection sensitivity (76 and 84%, respectively) compared to evaluation of only VNC (71 and 81%, respectively) or post-contrast images (64 and 80%, respectively). The sensitivity of joint reader evaluation of side-by-side-images reached almost 86% and was not significantly different from TNC images (p = 0.77). All stones larger than 3 mm were correctly detected by side-by-side-evaluation. Dose reduction of 55% could be achieved by omitting TNC scans. Conclusion: Side-by-side-VNC and post-contrast image evaluation enable detection of clinically significant urolithiasis on single-phase split bolus DE-CTU with significant dose reduction. Advances in knowledge: This study shows that single-phase DE-CTU is feasible if VNC imaging is simultaneously utilised with post-contrast images.

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Characterization of Small (< 4 cm) Focal Renal Lesions: Diagnostic Accuracy of Spectral Analysis Using Single-Phase Contrast-Enhanced Dual-Energy CT

American Journal of Roentgenology ◽

10.2214/ajr.17.17824 ◽

2017 ◽

Vol 209 (4) ◽

pp. 815-825 ◽

Cited By ~ 10

Author(s):

Bhavik N. Patel ◽

Alex Bibbey ◽

Kingshuk R. Choudhury ◽

Richard A. Leder ◽

Rendon C. Nelson ◽

...

Keyword(s):

Spectral Analysis ◽

Diagnostic Accuracy ◽

Phase Contrast ◽

Single Phase ◽

Dual Energy ◽

Dual Energy Ct ◽

Renal Lesions ◽

Contrast Enhanced

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Technical Note: Using virtual non‐contrast images from dual‐energy CT to eliminate the need of pre‐contrast CT for X‐ray radiation treatment planning of abdominal tumors

Medical Physics ◽

10.1002/mp.14702 ◽

2021 ◽

Author(s):

George Noid ◽

Diane Schott ◽

Eric Paulson ◽

Justin Zhu ◽

Jainil Shah ◽

...

Keyword(s):

Treatment Planning ◽

Radiation Treatment ◽

Dual Energy ◽

Technical Note ◽

Dual Energy Ct ◽

Radiation Treatment Planning ◽

X Ray ◽

Abdominal Tumors ◽

Contrast Ct

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Abstract P327: Utilizing Iodine Contrast Extravasation Post Reperfusion and Dual Energy Ct Imaging to Predict Risk of Hemorrhagic Conversion in Acute Stroke Patients

Stroke ◽

10.1161/str.52.suppl_1.p327 ◽

2021 ◽

Vol 52 (Suppl_1) ◽

Author(s):

Tri Huynh* ◽

Niran Vijayaraghavan* ◽

Hannah Branstetter ◽

Natalie Buchwald ◽

Justin De Prey ◽

...

Keyword(s):

Acute Stroke ◽

Infarct Volume ◽

Reperfusion Therapy ◽

Dual Energy ◽

Ct Imaging ◽

Dual Energy Ct ◽

Stroke Patients ◽

Post Intervention ◽

Contrast Extravasation ◽

Post Contrast

Introduction: Hyperintense acute reperfusion marker (HARM) has been identified on post-contrast magnetic resonance imaging (MRI) to be a marker of hemorrhagic conversion (HC) post reperfusion therapy in acute stroke patients. We have previously described a case where MRI HARM was mimicked on post contrast computed topography (CT) imaging in an acute stroke patient post reperfusion. Dual-Energy (DECT) allows for differentiation between acute blood and iodine contrast extravasation (ICE), and thus can have utility when ICE is present. Here we sought to validate whether post-intervention ICE/CT hyperdensity reperfusion maker (CT HARM), and contrast subtracted on DECT is associated with HC in acute stroke patients. Method: Data was obtained from our Institutional Review Board approved stroke admission database from January 2017 to November 2019, including ischemic stroke patients that received thrombolysis or thrombectomy, had evaluable images within 24 hours of admission, and received a DECT. Ischemic volumes of the stroke was measured on diffusion-weighted image (DWI). ICE was measured on CT head and DECT using the freehand 3D region of interest tool on the Visage Imaging PACS System. Susceptibility weighted MRI sequences were used to grade HC. Data analysis was conducted with regression modeling. Results: A total of 82 patients were included, 49% women, median age 73 (interquartile range (IQR), 61- 77), admission NIHSS 12 (IQR, 7 - 21), 24 hour change in NIHSS 4 (IQR, 0 -13), glucose 125 (IQR, 106 -158), creatinine 1.0 (IQR, 0.8 - 1.2), infarct volume 50.6 ± 7.1 mL, 48% treated with thrombectomy, 7% with PH-1 or PH-2 identified on MRI, and 56% with MCA infarcts. ICE volume was 2.6 ± 1.0 mL and DECT volume was 2.2 ± 1.1mL. ICE increased the likelihood of MRI confirmed PH-1 or PH-2 hemorrhagic conversion (odds ratio (OR) 14.34, 95% confidence interval (CI) 5.74 - 22.94) and decreased likelihood of increase in NIHSS at 24 hours (OR 0.20, 95% CI 0.01 to 0.40). There were no other significant associations with ICE or DECT volumes. Conclusion: Our results are supportive of our proposed association between CT HARM and risk of HC. More studies are needed to study whether quantitative of DECT can be predictive of stroke outcomes post reperfusion therapy.

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