Naveen Kulkarni MD, Presenter: Nothing to Disclose

Gaurav Shyam Desai MBBS, Abstract Co-Author: Nothing to Disclose

Mukta Joshi, Abstract Co-Author: Employee, General Electric Company, Chalfont St Giles, United Kingdom

Cristy Savage RT, Abstract Co-Author: Nothing to Disclose

Dushyant V. Sahani MD, Abstract Co-Author: Grant, General Electric Company

To assess utility of material density (MD) iodine images derived from single-source dual-energy MDCT (SSDE CT) scanner in improving the characterization of renal mass.

In this IRB approved study 38 patients (M:F- 20:18, Age-36-78) underwent a unenhanced and contrast enhanced acquisition at 100 sec delay using single energy mode and DE acquisition (scan mode was Gemstone Spectral Imaging with medium body at 0.8s rotation, helical mode, rapid kVp switching between 80 and 140 in < 0.5 msec, pitch of 1.375:1) at a delay of 3 min on a 64-detector SS-DECT (CT750 HD scanner, GE). From DE acquisition MD iodine image series were reconstructed using two material decomposition technique on commercially available software. Iodine images display the presence or absence of iodine in each pixel but do not contain CT attenuation information. Each lesion was evaluated for the presence or absence of enhancement on iodine images and correlated with the enhancement characteristics on unenhanced and enhanced images. The enhancing lesions were further evaluated by histopathological examination or additional imaging studies.

Out of the 57 lesions (0.6-5.2cm, mean-3.1cm) analyzed 45 lesions did not show enhancement (mean-2.9cm) and 12 lesions (mean-2.4cm) showed enhancement. The final diagnosis was confirmed in the enhancing lesions either by either biopsy, MRI or lesion stability. When reviewed independently, iodine images had good sensitivity (88.4%) and specificity (90.1%) in detecting enhancing lesions. The negative predictive value for lack of enhancement was (88.5%) and positive predictive value (85%). Combination of unenhanced, enhanced and iodine images further improved the diagnostic accuracy in distinguishing cystic from enhancing solid lesions.

Iodine images from DE acquistion can considerably improve the diagnostic confidence in identifying the presence or absence of enhancement in the renal mass.

DE technique may allow for evaluation of renal masses on post-contrast CT acquisitions alone thereby limiting the patients radiation dose and lowering the number of indeterminate lesions.

Kulkarni, N, Desai, G, Joshi, M, Savage, C, Sahani, D, Gemstone Detector Single-Source Dual-Energy CT Iodine Images Ability to Improved Characterization of Renal Mass.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9014340.html