The role of the ADC value in the characterisation of renal carcinoma by diffusion-weighted MRI

Abstract

ABSTRACT. The purpose of this study is to evaluate the role of diffusion-weighted imaging (DWI) in combination with T 1 and T 2 weighted MRI for the characterisation of renal carcinoma. The institutional review board approved the study protocols and waived informed consent from all of the patients. 47 patients (32 male and 15 female; age range, 21-85 years; median age, 65 years) who had suspected renal lesions on abdominal CT underwent MRI for further evaluation and characterisation of the lesions from April 2005 to August 2007 in our university hospital. A region of interest was drawn around the tumour area on apparent diffusion coefficient (ADC) maps. Final diagnosis was confirmed by histological examination of surgical specimens from all patients. The ADC value was significantly higher in renal cell carcinoma (RCC) ; p50.0004), whereas intensity on T 1 and T 2 weighted imaging did not reach statistical significance. In conclusion, DWI has clinical value in the characterisation of renal carcinomas and could be applied in clinical practice for their management. Renal cell carcinoma (RCC) is the most common primary malignant tumour of the kidney; it accounts for 2-3% of all adult cancers and is the sixth cause of death by tumour throughout the world. More than 80% of renal cancers that arise in the renal parenchyma are RCC, whereas the majority of renal pelvis cancers are transitional cell carcinomas (TCCs) [1][2][3]. The three most common subtypes of RCC are (i) clear cell carcinoma, one of the most common types, accounting for 70-80% of cases; (ii) papillary renal cell carcinoma, accounting for about 10-15% of cases; and (iii) chromophobe renal carcinoma, which is the least common, accounting for 5% of all RCCs. The annual rate of RCC diagnosis is increasing as a result of incidental detection by crosssectional abdominal imaging of patients with suspected abdominal disorders. Increased detection rates carry a favourable prognosis; however, mortality from RCC has not decreased [2][3][4].Diffusion-weighted imaging (DWI) is frequently used in cranial MRI studies and has shown potential for the characterisation of lesions such as acute cerebral infarctions, intracranial tumours, various infectious diseases and metabolic disorders [5][6][7][8]. The role of DWI is limited outside the central nervous system, owing to its inherent extreme sensitivity to motion, such as that related to respiration, peristalsis and artefacts, thus resulting in a high signal to noise ratio. With the development of advanced MR technology and the use of faster robust sequences, better quality has been obtained in abdominal imaging [9]. DWI with high b-values has been reported to have a high sensitivity for depicting malignant disease. Apparent diffusion coefficient (ADC) values of malignant hepatic, ovarian, breast, prostatic, colonic and uterine cervical tumours were lower than those of benign lesions or normal tissue [10][11][12][13][14][15][16][17][18].Previous studies have suggested that patients with chromophobe and papillary RCC ha...

Utility of Apparent Diffusion Coefficients in the Evaluation of Solid Renal Tumors at 3T

“…ADCs of renal tumor obtained with 3T MRI tended to be lower than those obtained with 1.5T MRI. The ADC of clear cell RCC with 1.5T MRI was reported to be within the range of 1.54-1.85 © 10 -3 mm 2 /s, [15][16][17][18]20 and between 1.381-1.698 © 10 -3 mm 2 /s with 3T MRI; In our study, the ADC was 1.423 © 10 -3 mm 2 /s. The ADC of AML with 1.5T MRI was reported to be within the range of 0.74 -1.58 © 10 -3 mm 2 /s.…”

“…With regard to MRI, diffusion-weighted MRI (DWI) has recently been used to differentiate different subtypes of RCC and fat poor AML and clear cell RCC. [15][16][17][18][19][20] However, almost all these studies were performed using MRI at 1.5T. To date, only 2 studies, which examined only RCC but not benign renal tumors, have used MRI at 3T.…”

The Changing Face of Renal-Cell Carcinoma

“…37,38 Use of diffusion-weighted MRI also allowed separation of clear RCC and nonclear RCC. 39 Additionally, dynamic contrast-enhanced MRI was able to detect vascular changes induced by sunitinib in xenograft renal tumors, demonstrating the potential utility of dynamic contrast-enhanced MRI in selecting the dose and schedule of angiogenic compounds. 40 Guimaraes et al 41 have shown the ability to identify metastatic lymph node in renal carcinoma using lymphotrophic nanoparticle-enhanced MRI.…”

Diffusion weighted MRI for detecting and monitoring cancer: a review of current applications in body imaging

“…Manenti et al (77) have reported significant differences among the ADC values of renal carcinomas and normal parenchyma; however, their analysis did not reveal a significant difference in the mean ADC value of the individual histological variants of renal carcinoma. In another study, Paudyal et al (78) demonstrated that ADC values were significantly higher in renal cell carcinomas (RCC) than in transitional cell carcinomas. Further analysis of the histological subtypes of RCC demonstrated that clear-cell carcinomas had lower ADC values than non-clear-cell carcinomas, most likely because of differences in cellularity.…”