Enhancement patterns of renal masses during multiphase helical CT acquisitions.
BACKGROUND
To describe the appearance of renal masses during multiphase helical computed tomography (CT) acquisition and evaluate the impact of a cortical nephrographic phase on diagnosis.


METHODS
The CT examinations of 33 patients with 37 lesions [18 renal cell carcinomas (RCC), nine solid tumors, 10 cystic lesions] were reviewed to characterize renal masses during four phases of CT scanning: plain, cortical nephrographic, tubular nephrographic, and pyelographic. Two reviewers analyzed all lesions on the complete data set, and a third reviewer analyzed three combinations of images separately: (1) plain and tubular nephrographic phases, (2) plain and cortical nephrographic phases, and (3) three phases combined. Receiver operating characteristics (ROC) curves were generated to determine the respective value of each combination in lesion characterization.


RESULTS
During the cortical nephrographic phase, hyperdensity of solid renal masses was 100% specific and 22% sensitive for RCC, whereas combining hyperdense and isoattenuating heterogeneous masses was 91% specific and 56% sensitive. ROC curves demonstrated a sensitivity of 85%, 90%, 100% for the three combinations, respectively, with a constant specificity of 88% for diagnosing RCC.


CONCLUSIONS
The cortical nephrographic phase is useful to characterize renal masses and should be included in the routine helical CT protocol.
Garant
M
M
Department of Diagnostic Radiology, Montreal General Hospital, Quebec, Canada.
Bonaldi
V M
VM
Taourel
P
P
Pinsky
M F
MF
Bret
P M
PM
D000038:Abscess / Q000000981:diagnostic imaging / Q000473:pathology; D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000556:secondary; D018249:Adenoma, Oxyphilic / Q000000981:diagnostic imaging / Q000473:pathology; D000328:Adult; D000368:Aged; D018207:Angiomyolipoma / Q000000981:diagnostic imaging / Q000473:pathology; D001706:Biopsy; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging / Q000473:pathology; D002295:Carcinoma, Transitional Cell / Q000000981:diagnostic imaging / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007674:Kidney Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D052177:Kidney Diseases, Cystic / Q000000981:diagnostic imaging / Q000473:pathology; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000556:secondary; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed