Diffusion-weighted MR imaging in the evaluation of renal tumours.
The aim of this study was to evaluate the capability and the reliability of diffusion-weighted MR imaging to differentiate benign from malignant renal lesions. Twenty healthy volunteers and 48 patients with known renal lesions underwent MR of the kidneys by using a 1.5 T superconductive magnet. Diffusion-weighted images (DWI) were obtained on the axial plane during breathhold (17 s) with a SE EPI single shot sequence using a b value of 500 s/mm2. One region of interest (ROI) (lesions < than 3 cm) or 3 ROI (lesions > than 3 cm) were placed within the lesion for the measurement of apparent diffusion coefficient (ADC). ADC map was obtained at each slice position. Mean ADC value in normal renal parenchyma was 2.2 +/- 0.20 x 10(-3) mm2/s, while ADC values in simple cysts (n = 20) were higher (mean ADC values 3.65 +/- 0.09 x 10(-3) mm2/s). Solid benign and malignant renal tumors (n = 19) showed a mean ADC value of 1.7 +/- 0.48 x 10(-3) mm2/sec. The comparison between ADC values in normal parenchyma group and tumour group were found to be statistically significant (p < 0.0001). ADC values of cystic renal cell carcinomas were higher than those of clear cell carcinomas (p < 0.001). In conclusion, DW MRI of the kidney seems to be a reliable means for differentiating normal renal parenchyma from different renal tumors.
Squillaci
E
E
Dept. of Diagnostic Imaging and Interventional Radiology, University of Tor Vergata, Rome, Italy. ettoresquillaci@tiscali.it
Manenti
G
G
Di Stefano
F
F
Miano
R
R
Strigari
L
L
Simonetti
G
G
D018262:Adenocarcinoma, Clear Cell / Q000175:diagnosis / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000175:diagnosis / Q000473:pathology; D002292:Carcinoma, Renal Cell / Q000175:diagnosis / Q000473:pathology; D003560:Cysts / Q000175:diagnosis; D004058:Diffusion; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007668:Kidney / Q000378:metabolism; D007674:Kidney Diseases / Q000473:pathology; D007680:Kidney Neoplasms / Q000175:diagnosis* / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D013997:Time Factors