An augmented patient-specific approach to administration of contrast agent for CT renal angiography

• Published in: International Brazilian Journal of Urology Vol. 45; no. 5; pp. 1022 - 1032
• Main Authors: Saade, Charbel, Hamieh, Nadine, Deeb, Ibrahim Al-Sheikh, Haddad, Maurice, Abi-Ghanem, Alain S, Ghieh, Diamond, El-Merhi, Fadi
• Format: Journal Article
• Language: English
• Published: Brazil Sociedade Brasileira de Urologia 01.09.2019
• Subjects: Computed Tomography Angiography; Kidney; Original; Radiation Dosage; Computed Tomography Angiography; Kidney; Radiation Dosage
• ISSN: 1677-5538; 1677-6119
• DOI: 10.1590/S1677-5538.IBJU.2018.0366

This hybrid retrospective and prospective study performed on 200 consecu¬tive patients undergoing renal CTA, investigates the opacification of renal vasculature, radiation dose, and reader confidence. 100 patients were assigned retrospectively to protocol A and the other 100 were allocated prospectively to protocol B. Both protocols implemented a contrast material and saline flow rate of 4.5 mL/sec. Protocol A utilized a 100 mL of low-osmolar nonionic IV contrast material (Ioversol 350 mg I/mL) while protocol B employed a patient-tailored contrast media formula using iso-osmolar non-ionic (Iodixanol 320 mg I/mL). Arterial opacification in the abdominal aorta and in the bilateral main proxi¬mal renal arteries demonstrated no statistical significance (p>0.05). Only the main dis¬tal renal artery of the left kidney in protocol B was statistically significant (p<0.046). In the venous circulation, the IVC demonstrated a significant reduction in opacification in protocol B (59.39 HU ± 19.39) compared to A (87.74 HU ± 34.06) (p<0.001). Mean CNR for protocol A (22.68 HU ± 13.72) was significantly higher than that of protocol B (14.75 HU ± 5.76 p<0.0001). Effective dose was significantly reduced in protocol B (2.46 ± 0.74 mSv) compared to A (3.07 ± 0.68 mSv) (p<0.001). Mean contrast media volume was reduced in protocol B (44.56 ± 14.32 mL) with lower iodine concentration. ROC analysis demonstrated significantly higher area under the ROC curve for protocol B (p<0.0001), with inter-reader agreement increasing from moderate to excellent in renal arterial visualization. Employing a patient-tailored contrast media injection protocol shows a significant refinement in the visualization of renal vasculature and reader confidence during renal CTA.