Material density iodine images in dual-energy CT: Detection and characterization of hypervascular liver lesions compared to magnetic resonance imaging

Purpose: To determine the diagnostic potential of Material Density (MD) iodine images in dual-energy CT (DECT) for the detection and characterization of hypervascular liver lesions compared to monenergetic 65 keV images, using MRI as the standard. Materials and methods: The study complied with HIPAA guidelines and was approved by the institutional review board. Fifty-two patients (36 men, 16 women; age range, 29-87 years) with 236 hypervascular liver lesions (benign, n = 31; malignant, n = 205; mean diameter, 29.4 mm; range: 6-90.6 mm) were included. All of them underwent both contrast-enhanced single-source DECT and contrast-enhanced abdominal MRI within three months. Late arterial phase CT imaging was performed with dual energies of 140 and 80 kVp. Protocol A showed monoenergetic 65 keV images, and protocol B presented MD-iodine images. Three radiologists qualitatively evaluated randomized images, and lesion detection, characterization, and reader confidence were recorded. Liver-to-lesion ratio (LLR) and contrast-to-noise ratio (CNR) were assessed on protocol A, protocol B, and MRI. Paired t-tests were used to compare LLR, CNR, and the number of detected lesions. Results: LLR was significantly increased in protocol B (2.8 +/- 2.33) compared to protocol A (0.77 +/- 0.55) and MRI (0.61 +/- 0.66). CNR was significantly higher in protocol B (0.08 +/- 0.04) compared to protocol A (0.01 +/- 0.01) and MRI (0.01 0.01). All three observers correctly identified more liver lesions using protocol B vs protocol A: 83.13% vs 63.64%, 84.57% vs 68.09%, and 79.37% vs 65.52%. There was no significant difference between the three observers in classification of a lesion as benign or malignant. However, higher diagnostic confidence was reported more frequently by the experienced radiologist when using protocol B vs protocol A (84.6% vs 75%). Conclusion: MD-iodine images in DECT help to increase the conspicuity and detection of hypervascular liver lesions.