Arterial Spin-labeling MR Imaging of Renal Masses: Correlation with Histopathologic Findings

Abstract

Purpose:To assess the value of arterial spin-labeling (ASL) perfusion magnetic resonance (MR) imaging in the characterization of solid renal masses by using histopathologic findings as the standard of reference. Materials and Methods:This prospective study was compliant with HIPAA and approved by the institutional review board. Informed consent was obtained from all patients before imaging. Fortytwo consecutive patients suspected of having renal masses underwent ASL MR imaging before their routine 1.5-T clinical MR examination. Mean and peak tumor perfusion levels were obtained by one radiologist, who was blinded to the final histologic diagnosis, by using region of interest analysis. Perfusion values were correlated with histopathologic findings by using analysis of variance. A linear correlation model was used to evaluate the relationship between tumor size and perfusion in clear cell renal cell carcinoma (RCC). P , .05 was considered indicative of a statistically significant difference. Results:Histopathologic findings were available in 34 patients (28 men, six women; mean age 6 standard deviation, 60.4 years 6 11.7). The mean perfusion of papillary RCC (27.0 mL/min/100 g 6 15.1) was lower than that of clear cell RCC (171.6 mL/min/100 g 6 61.2, P = .001), chromophobe RCC (152.9 mL/min/100 g 6 80.7, P = .04), unclassified RCC (208.0 mL/min/100 g 6 41.1, P = .001), and oncocytoma (373.9 mL/min/100 g 6 99.2, P , .001). The mean and peak perfusion levels of oncocytoma (373.9 mL/ min/100 g 6 99.2 and 512.3 mL/min/100 g 6 146.0, respectively) were higher than those of papillary RCC (27.0 mL/min/100 g 6 15.1 and 78.2 mL/min/100 g 6 39.7, P , .001 for both), chromophobe RCC (152.9 mL/min/100 g 6 80.7 and 260.9 mL/min/100 g 6 61.9; P , .001 and P = .02, respectively), and unclassified RCC (208.0 mL/ min/100 g 6 41.1 and 273.3 mL/min/100 g 6 83.4; P = .01 and P = .03, respectively). The mean tumor perfusion of oncocytoma was higher than that of clear cell RCC (P , .001). Conclusion:ASL MR imaging enables distinction among different histopathologic diagnoses in renal masses on the basis of their perfusion level. Oncocytomas demonstrate higher perfusion levels than RCCs, and papillary RCCs exhibit lower perfusion levels than other RCC subtypes.q RSNA, 2012

Renal Arterial Spin Labeling Magnetic Resonance Imaging

“…In the case of renal cell carcinoma (RCC), not only the feasibility [43,44] of ASL but also the sensitivity of the perfusion response to tumor therapy was investigated. Perfusion measurements by ASL were able to differentiate renal masses with different histological findings [45] and cellularity [46,47].…”

Usefulness of Pseudocontinuous Arterial Spin-Labeling for the Assessment of Patients with Head and Neck Squamous Cell Carcinoma by Measuring Tumor Blood Flow in the Pretreatment and Early Treatment Period

“…[14][15][16] Thus, the role and potential of TBF measurement during treatment remain unclear. TBF measurement by pseudocontinuous arterial spinlabeling (pCASL), which was introduced for the noninvasive measurement of tissue blood flow without the need for a contrast agent and with no radiation exposure, 17,18 was recently demonstrated to be feasible and applicable for HNSCCs 19 ; pCASL thus has potential for the evaluation of treatment effects in patients with HNSCC without the risks with repetitive scanning of contrast-induced nephropathy during chemotherapy and increased radiation exposure. The purpose of the present study was to evaluate the diagnostic value of TBF assessed by pCASL for the determination of local control or failure in patients with HNSCC.…”

Diagnostic Imaging for Solid Renal Tumors: A Pictorial Review

“…This technique showed the ability to distinguish RCC subtypes by perfusion level, and RCC could also be separated from oncocytoma. A possible limitation to this technique is the lower sensitivity for detection of pRCC due to lower perfusion levels [78].…”