Diagnostic Utility of Diffusion-weighted Magnetic Resonance Imaging in Differentiating Small Solid XXXX ( <= 4 cm) at 3.0T Magnetic Resonance Imaging.

@entity1 @entity1637 @entity5 @entity1358 @entity359 @entity703
BACKGROUND: The aim of this study was to assess the performance of apparent diffusion coefficient (ADC) measurement obtained with diffusion-weighted magnetic resonance imaging (DW-MRI) to distinguish @entity1358 ( @entity1358 ) from small benign solid @entity703 ( <= 4 cm). METHODS: In this cross-sectional study, 49 consecutive @entity1 with histopathologically confirmed small solid @entity703 , and seven healthy volunteers were imaged using nonenhanced MRI and DW-MRI. The ADC map was calculated using the b values of 0, 50, 400, and 600 s/mm 2 and values compared via the Kruskal-Wallis and Mann-Whitney tests. The utility of ADC for differentiating @entity1358 and benign lesions was assessed using a receiver operating characteristic curve. Multiple nonenhanced MRI features were analyzed by Logistic regression. RESULTS: The @entity5 consisted of 33 cases of clear-cell @entity1358 (ccRCCs) and 16 cases of @entity5 , including 14 cases of minimal @entity359 and 2 cases of @entity1637 . The ADCs showed significant differences among @entity5 ([0.90    0.52] * 10-3 mm 2 /s), ccRCCs ([1.53    0.31] * 10-3 mm 2 /s) and the normal renal parenchyma ([2.22    0.12] * 10-3 mm 2 /s) (P < 0.001). Moreover, there was statistically significant difference between high and low-grade ccRCCs (P = 0.004). Using a cut-off ADC of 1.36 * 10-3 mm 2 /s, DW-MRI resulted in an area under the curve (AUC), sensitivity, and specificity equal to 0.839, 75.8%, and 87.5%, respectively. Nonenhanced MRI alone and the combination of imaging methods led to an AUC, sensitivity and specificity equal to 0.919, 93.9%, and 81.2%, 0.998, 97%, and 100%, respectively. The Logistic regression showed that the location of the center of the @entity5 (inside the contour of the kidney) and appearance of stiff blood vessel were significantly helpful for diagnosing ccRCCs. CONCLUSIONS: DW-MRI has potential in distinguishing ccRCCs from benign lesions in @entity1 small solid @entity703 ( <= 4 cm), and in increasing the accuracy for diagnosing ccRCCs when combined with nonenhanced MRI.
