Double-phase helical CT of small renal parenchymal neoplasms: correlation with pathologic findings and tumor angiogenesis.
OBJECTIVE
To correlate the enhancement pattern of double-phase helical computed tomography (CT) of small renal parenchymal neoplasms with pathologic findings and tumor angiogenesis, and evaluate whether the enhancement pattern would be useful in differentiating the histomorphologic types of small renal parenchymal neoplasms.


METHODS
Double-phase helical CT (5 mm slice) of the corticomedullary phase (CMP) and late nephrographic phase (NP) was performed in 40 surgically resected renal neoplasms <3.5 cm. The patterns of CT attenuation value and homogeneity were correlated with the subtypes of neoplasms, microvessel density, and the existence of intratumoral necrosis or hemorrhage.


RESULTS
Clear cell renal cell carcinomas (RCC) (n = 29) showed a peak attenuation value in the CMP of >100 HU [Hounsfield units]. Chromophobe cell RCC (n = 2) showed a peak attenuation value in the CMP of <100 HU. Papillary RCC (n = 5) showed a gradual enhancement with the attenuation value in the CMP of <100 HU. However oncocytomas (n = 2) and metanephric adenomas (n = 2) also showed patterns similar to these subtypes of RCC. The degree of enhancement in the CMP correlated with microvessel density (r = 0.87). All tumors with an homogeneous enhancement pattern did not show necrosis or hemorrhage on histologic specimen.


CONCLUSIONS
The enhancement pattern in double-phase helical CT was different among the subtypes of RCC, and correlated with microvessel density or the existence of intratumoral necrosis or hemorrhage. However it did not differentiate between RCC and other solid tumors.
Jinzaki
M
M
Department of Diagnostic Radiology, Keio University School of Medicine, Tokyo, Japan. jin-zaki@ja2.so-net.ne.jp
Tanimoto
A
A
Mukai
M
M
Ikeda
E
E
Kobayashi
S
S
Yuasa
Y
Y
Narimatsu
Y
Y
Murai
M
M
D000230:Adenocarcinoma / Q000098:blood supply / Q000000981:diagnostic imaging / Q000473:pathology; D018262:Adenocarcinoma, Clear Cell / Q000098:blood supply / Q000000981:diagnostic imaging / Q000473:pathology; D000236:Adenoma / Q000098:blood supply / Q000000981:diagnostic imaging / Q000473:pathology; D018249:Adenoma, Oxyphilic / Q000098:blood supply / Q000000981:diagnostic imaging / Q000473:pathology; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002292:Carcinoma, Renal Cell / Q000098:blood supply / Q000000981:diagnostic imaging / Q000473:pathology; D005260:Female; D006470:Hemorrhage / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007672:Kidney Cortex / Q000000981:diagnostic imaging / Q000473:pathology; D007679:Kidney Medulla / Q000000981:diagnostic imaging / Q000473:pathology; D007680:Kidney Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D008833:Microcirculation / Q000000981:diagnostic imaging / Q000473:pathology; D008875:Middle Aged; D009336:Necrosis; D009389:Neovascularization, Pathologic / Q000000981:diagnostic imaging* / Q000473:pathology; D009399:Nephrons / Q000000981:diagnostic imaging / Q000473:pathology; D011856:Radiographic Image Enhancement / Q000379:methods; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed / Q000379:methods*