Visual assessment of the intensity and pattern of T1 hyperintensity on MRI to differentiate hemorrhagic renal cysts from renal cell carcinoma

Choo Won Kim, Krishna P. Shanbhogue, Jessica Schreiber-Zinaman, Fang Ming Deng, Andrew B. Rosenkrantz

Research output: Contribution to journalArticle

7 Scopus citations

Abstract

OBJECTIVE. The purpose of this study was to apply a visual assessment of the intensity and pattern of T1 hyperintensity at MRI to differentiate hemorrhagic renal cysts from renal cell carcinoma (RCC). MATERIALS AND METHODS. A total of 144 T1-hyperintense renal lesions (62 cysts, all showing no enhancement on subtracted contrast-enhanced images and either 2-year stability or unenhanced CT density > 70 HU, and 82 histologically confirmed RCCs) in 144 patients were included. Two radiologists independently characterized qualitative features of the T1 hyperintensity in each lesion on unenhanced T1-weighted images. An additional radiologist placed ROIs to measure lesions' T1 signal intensity normalized to that of the psoas muscle. Chi-square and unpaired t tests were performed to compare the pattern of T1 hyperintensity between groups. RESULTS. The T1 hyperintensity was considered marked in 62.9% of cysts and 17.1% of RCCs for reader 1 and in 46.8% of cysts and 8.5% of RCCs for reader 2 (p < 0.001). The T1 hyperintensity exhibited a diffusely homogeneous distribution in 88.7% of cysts and 7.3% of RCCs for reader 1 and in 72.6% of cysts and 4.9% of RCCs for reader 2 (p < 0.001). The combination of both diffusely homogeneous distribution and marked degree of T1 hyperintensity achieved sensitivities of 40.3-56.5%, specificities of 97.6-98.8%, and accuracies of 73.6-79.9% for the diagnosis of T1-hyperintense cysts. The two cases of RCC exhibiting this imaging pattern for at least one reader were both papillary RCCs. Normalized signal intensity was 2.39 ± 0.99 in T1- hyperintense cysts versus 2.12 ± 0.84 in T1-hyperintense RCCs (p = 0.088). CONCLUSION. Diffuse T1 hyperintensity, particularly when marked, strongly i ndicates a hemorrhagic cyst rather than an RCC. Deferral of follow-up imaging may be considered when this imaging appearance is encountered at unenhanced MRI.

Original languageEnglish (US)
Pages (from-to)337-342
Number of pages6
JournalAmerican Journal of Roentgenology
Volume208
Issue number2
DOIs
StatePublished - Feb 1 2017
Externally publishedYes

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Keywords

  • Hemorrhage
  • MRI
  • Renal cell carcinoma
  • Renal cyst

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging

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