Combined late gadolinium-enhanced and double-echo chemical-shift MRI help to differentiate renal oncocytomas with high central T2 signal intensity from renal cell carcinomas.
American Journal of Roentgenology. 2013-04-01; 200(4): 830-838
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1. AJR Am J Roentgenol. 2013 Apr;200(4):830-8. doi: 10.2214/AJR.12.9122.
Combined late gadolinium-enhanced and double-echo chemical-shift MRI help to
differentiate renal oncocytomas with high central T2 signal intensity from renal
Cornelis F(1), Lasserre AS, Tourdias T, Deminière C, Ferrière JM, Le Bras Y,
(1)Department of Radiology, Pellegrin Hospital, Pl Amélie Raba Léon, 33076
OBJECTIVE: The purpose of our study was to evaluate the combination of dynamic
contrast-enhanced T1-weighted and double-echo gradient-echo MR imaging to
distinguish renal oncocytoma with high T2 signal intensity centrally from renal
cell carcinoma (RCC).
MATERIALS AND METHODS: Between 2006 and 2011, 63 renal tumors (59 patients)
presenting with a high signal intensity (SI) central area on T2-weighted
sequences were imaged with dynamic contrast-enhanced sequences, including phases
later than 5 minutes after contrast injection, and double-echo chemical-shift
sequences were selected from our institutional database. Two experienced
radiologists visually assessed presence and distribution of signal enhancement of
central areas after injection and measured SI changes on opposed-phase images for
calculation of the SI index and tumor-to-spleen ratio. Cutoff values were derived
from the receiver operating characteristic (ROC) curve.
RESULTS: There were 19 oncocytomas (16 patients), 43 RCCs (42 patients), and one
leiomyoma. Complete late enhancement of the central area was observed in 14
oncocytomas (74%) and in five RCCs (12%) (p = 0.05). The combination of complete
enhancement and SI index lower than 2% (p = 0.02) or tumor-to-spleen ratio higher
than -6% (p = 0.001) provided sensitivity of 36% and 55%, specificity of 95% and
97%, positive predictive value of 67% and 86%, and negative predictive value of
84% and 88%, respectively, for diagnosis of oncocytomas.
CONCLUSION: Absence of central area SI inversion or presence of a signal drop on
chemical-shift imaging may rule out the diagnosis of oncocytoma.
PMID: 23521457 [Indexed for MEDLINE]