Diagnostic utility of diffusion-weighted magnetic resonance imaging in two common renal tumors

Abstract

Abstract. The aim of the present study was to evaluate the utility of diffusion-weighted magnetic resonance imaging (DWI) in the diagnosis of common renal tumors. Conventional magnetic resonance imaging and DWI were performed on 85 patients with renal lesions (54 renal carcinoma and 31 renal angiomyolipoma cases). The apparent diffusion coefficient (ADC) values in each case at b=800 sec/mm 2 were measured in the ADC maps using a statistical software package. The 54 cases of renal cell carcinoma showed a high signal intensity in the parenchyma, and the 31 renal angiomyolipoma cases showed a well-defined mixed signal intensity on DWI. The soft-tissue component showed a high signal intensity and the fat tissue showed a low signal intensity on DWI. When the b-value was set to 800 sec/mm 2 , the mean ADC was significantly lower in the renal carcinoma cases than in the renal angiomyolipoma cases. In conclusion, the measurement of ADC on DWI can reveal the structure of renal tumors, which is beneficial in diagnosing and determining the prognosis of benign and malignant renal tumors.

Multiparametric MRI of Solid Renal Masses: Principles and Applications of Advanced Quantitative and Functional Methods for Tumor Diagnosis and Characterization

“…Nevertheless, routine DWI‐MRI with ADC measurement remains valuable and reliable at high b‐values and is overall less vulnerable to low SNR 34,39 . In addition, DWI/IVIM may continue to play a vital role in those patients who are unable to receive GBCA 36 …”

“…34,39 In addition, DWI/IVIM may continue to play a vital role in those patients who are unable to receive GBCA. 36 T 1 Mapping BACKGROUND. T 1 mapping (relaxometry) is a highly versatile technique that probes tissue microstructure, serving as a potential imaging marker for different pathological conditions such as fibrosis and inflammation.…”

“…34,36 A separate study found conflicting results, demonstrating higher mean ADC in AML compared to solid RCCs (1.83 AE 0.35 Â 10 À3 mm 2 /sec vs. 1.42 AE 0.16 Â 10 À3 mm 2 /sec, P = 0.000). 36 With regards to oncocytoma, a recent study conducted on a 3T MRI system demonstrated higher mean ADC values for oncocytoma compared to RCCs (2.16 AE 0.21 Â 10 À3 mm 2 /sec, P < 0.001). 37 Regarding distinction of RCC sub-types, mean ADC values were increased in ccRCC (1.50 AE 0.13 Â 10 À3 mm 2 /sec, P < 0.001) compared to the more indolent chromophobe (chromophobe RCC [chRCC]) (1.11 AE 0.10 Â 10 À3 mm 2 /sec, P < 0.001) and papillary (p)RCC (0.76 AE 0.09 Â 10 À3 mm 2 /sec, P < 0.001), 37 which agree with the results published by Hotker et al, in which ADC values for ccRCC were significantly higher than other subtypes (P < 0.05), including pRCC and chRCC regardless of whether single ROI or whole-tumor assessment was used.…”

“…Other studies summarized in a systemic review by Ye et al have also demonstrated similarly decreased ADC values in AML relative to solid RCC 27 . Whereas the reduced ADC values for AML could be attributed to the muscular components of the SRM causing increased restricted diffusion, the relatively higher ADC values of ccRCC could reflect the intratumoral microcystic or necrotic features, which are challenging to avoid when delineating regions‐of‐interest (ROIs) at the time of imaging analysis 34,36 . A separate study found conflicting results, demonstrating higher mean ADC in AML compared to solid RCCs (1.83 ± 0.35 × 10 −3 mm 2 /sec vs. 1.42 ± 0.16 × 10 −3 mm 2 /sec, P = 0.000) 36 .…”

“…Whereas the reduced ADC values for AML could be attributed to the muscular components of the SRM causing increased restricted diffusion, the relatively higher ADC values of ccRCC could reflect the intratumoral microcystic or necrotic features, which are challenging to avoid when delineating regions‐of‐interest (ROIs) at the time of imaging analysis 34,36 . A separate study found conflicting results, demonstrating higher mean ADC in AML compared to solid RCCs (1.83 ± 0.35 × 10 −3 mm 2 /sec vs. 1.42 ± 0.16 × 10 −3 mm 2 /sec, P = 0.000) 36 . With regards to oncocytoma, a recent study conducted on a 3T MRI system demonstrated higher mean ADC values for oncocytoma compared to RCCs (2.16 ± 0.21 × 10 −3 mm 2 /sec, P < 0.001) 37 …”