Small Renal Masses
- 1 September 2000
- journal article
- Published by American Roentgen Ray Society in American Journal of Roentgenology
- Vol. 175 (3), 751-757
- https://doi.org/10.2214/ajr.175.3.1750751
Abstract
OBJECTIVE. The aim of our study was to characterize renal lesions equal to or smaller than 3.0 cm using dynamic contrast-enhanced MR imaging with fat suppression by means of quantitative analysis of signal intensity. MATERIALS AND METHODS. We retrospectively reviewed the MR imaging examinations of 35 patients (20 with renal cell carcinoma, eight with angiomyolipoma, and seven with complicated cysts) who were studied with spin-echo and dynamic fat-suppressed gradient-recalled echo MR sequences, before and after the administration of gadopentetate dimeglumine. Every 30 sec after contrast injection, we measured the lesion percentage of enhancement and the ratio of contrast (lesion—renal cortex signal intensity difference) to noise. RESULTS. Ten renal cell carcinomas were classified as hypervascular (enhancement greater than that of renal cortex) and 10 as hypovascular. The percentage of enhancement of hypervascular carcinomas was similar to that of renal cortex until 150 sec and greater in the late sequences (180-210 sec, p < 0.01). Hypovascular carcinomas had a lower percentage of enhancement than hypervascular carcinomas (60-210 sec, p < 0.005). Angiomyolipomas, after an early enhancement peak, showed values similar to those of hypovascular carcinomas. Complicated cysts had very low enhancement (p < 0.001). The baseline contrast-to-noise ratio was negative for all lesions (hypointensity with respect to renal cortex). After gadolinium injection, the contrast-to-noise ratio of hypervascular carcinomas rose, becoming positive after 150 sec. Until 60 sec, the contrast-to-noise ratio of hypovascular carcinomas declined slightly, whereas that of angiomyolipomas and cysts fell sharply; then the three curves remained stable (60-210 sec, p < 0.05 for all matches except angiomyolipomas versus cysts). CONCLUSION. Quantitative analysis of signal intensity variations during dynamic contrast-enhanced MR imaging with fat suppression can be useful in the characterization of small renal lesions.Keywords
This publication has 20 references indexed in Scilit:
- Problems in the detection and characterization of small renal masses.Radiology, 1996
- Dynamic MRI of Small Renal Cell CarcinomaJournal of Computer Assisted Tomography, 1995
- Renal lesions: controlled comparison between CT and 1.5-T MR imaging with nonenhanced and gadolinium-enhanced fat-suppressed spin-echo and breath-hold FLASH techniques.Radiology, 1992
- The small (less than or equal to 3.0 cm) renal parenchymal tumor: detection, diagnosis, and controversies.Radiology, 1991
- Combined gadolinium-enhanced and fat-saturation MR imaging of renal masses.Radiology, 1991
- Observations on the growth of renal neoplasms.Radiology, 1990
- Renal masses: evaluation with gradient-echo Gd-DTPA-enhanced dynamic MR imaging.Radiology, 1990
- Conservative Surgical Treatment of Renal Cell Carcinoma: Clinical Experience and Reappraisal of IndicationsJournal of Urology, 1988
- Improvement in Survival of Patients with Renal Cell Carcinoma—The Role of the Serendipitously Detected TumorJournal of Urology, 1988
- Focal renal masses: magnetic resonance imaging.Radiology, 1984