Differential diagnosis of the small renal masses: role of the apparent diffusion coefficient of the diffusion-weighted MRI (original) (raw)
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BMC Urology, 2021
Background MRI is playing an increasing role in risk stratification and non-invasive diagnosis of the undifferentiated small renal mass. This study was designed to assess the reliability of MRI in diagnostic evaluation of renal masses, specifically characterising lesions with diffusion weighted imaging (DWI) and apparent diffusion coefficient (ADC) values. Methods This is a retrospective analysis of patients undergoing MRI as part of their clinical workup for a renal mass suspicious for renal cell carcinoma (RCC) on CT or ultrasound followed by biopsy and/or surgical excision. All cases were conducted on 3 Tesla MRI, with conventional breath-held sequences, DWI and dynamic contrast enhanced phases. Tumour regions of interest were evaluated on ADC maps and compared with T2 weighted and post-contrast images. Results Of the 66 renal tumours included, 33 (50.0%) were Clear Cell RCC, 11 (16.7%) were Oncocytoma, nine (13.6%) were Angiomyolipoma (AML), nine (13.6%) were Papillary RCC and f...
Journal of Pre-Clinical and Clinical Research, 2015
Introduction. Renal cell carcinoma (RCC) is the most common malignant epithelial tumour of the kidney, accounting for 85-90% of all solid renal tumours in adults and comprising 1-3% of all malignant visceral neoplasms. Recently, computed tomography (CT) has been considered the 'gold standard' in the diagnostic imaging of RCC; however, the use of CT is always associated with radiation exposure and consequently carries a significant increase in the risk of malignancy for patients with neoplastic processes. In recent years, magnetic resonance imaging (MRI) is increasingly attracting the attention of clinicians as the method of choice for the diagnosis and staging of RCC, due to several advantages over CT. Materials and method. The study involved 62 adult patients with a pathologically verified clear cell subtype of the renal cell carcinoma (ccRCC) and 15 healthy volunteers. All patients underwent renal MRI which included diffusion-weighted imaging (DWI) with subsequent apparent diffusion coefficient (ADC) measurement. Results. A significant difference was observed in the mean ADC value of the normal renal parenchyma and ccRCC-1.82 ± 0.16 × 10-3 mm 2 /s vs 2.15 ± 0.12 × 10-3 mm 2 /s, respectively (р < 0,05). Additionally, statistically reliable differences in ADC values in patients with high and low ccRCC grades were obtained: in patients with the I grade, the mean ADC value was 1.92 ± 0.12 × 10-3 mm 2 /s, in patients with the II grade, this value was 1.84 ± 0.14 × 10-3 mm 2 /s, in patients with the III grade, the mean ADC value was 1.79 ± 0.12 × 10-3 mm 2 /s, and in patients with the IV grade of nuclear polymorphism the mean ADC value was 1.72 ± 0.11 × 10-3 mm 2 /s (p <0.05). Conclusions. The data obtained in the survey show a significant restriction in the diffusion of hydrogen molecules in tissues of ccRCC, compared to the healthy renal parenchyma due to the tumour's greater density. A statistically significant difference was observed in the mean ADC values of ccRCC tumours with different Fuhrman nuclear grades: tumours with a low grade of differentiation demonstrated higher mean ADC values compared to highly differentiated tumours. Application of DWI modality of MR imaging with ADC calculation allows to obtain valuable information that is vital for the diagnosis of ccRCC and differentiation of its degree of malignancy.
The Egyptian Journal of Radiology and Nuclear Medicine, 2017
Objective: The prognosis of different histologic subtypes of RCC varies and affects management. Patients with chromophobe or papillary RCC have better prognosis than those with clear cell RCC. The aim of our work was to study the utility of DCE and DWI in the preoperative prediction of renal cell carcinoma subtypes, using histopathology as a gold standard method of diagnosis. Patients and methods: Thirty five patients with 38 renal masses were included in the study. All had DCE MRI studies with DWI sequences, CER and ADC values calculation for normal and diseased renal tissues. Results: The Mean ADC value of normal renal parenchyma was significantly higher than RCC. The CER and ADC values for Clear cell RCC were higher than Papillary and Chromophobe RCC. No statistically significant difference was found between the CER & ADC values for Papillary and Chromophobe RCC. CER & ADC values of clear RCC were higher than non clear RCC. Conclusions: DCE MRI in addition to DWI & ADC appears as a very helpful imaging tool in the differentiation between clear cell and non-clear cell RCCs.
The Egyptian Journal of Radiology and Nuclear Medicine, 2016
Previous studies suggested that the apparent diffusion coefficient (ADC) value could help in the differentiation and characterization of the benign and malignant renal masses. However, there is still wide overlap in the ADC values between the benign and malignant tumors. Objectives: To retrospectively assess the usefulness of the diffusion weighted imaging (DWI) for the characterization and differentiation between benign and malignant renal masses. Methods: A total of 87 renal and/or upper ureteric masses were included in our study. The signal intensity of the lesions was assessed on both the DWI and ADC map and the ADC value was calculated. t test, ANOVA test and Receiver operating characteristic (ROC) curve analysis were performed. Results: The ADC values of benign lesions were significantly higher than those of the malignant masses [3.2 versus 1.3 Â 10 À3 mm 2 /s], Median, P < 0.0001.The sensitivity and specificity of the DWI for the differentiation of benign and malignant masses were 98% and 73% using an ADC cutoffvalue of 2.2. Clear cell renal cell carcinoma demonstrates higher ADC value than non clear cell RCC. Conclusion: DWI-MRI has a role in differentiation of benign and malignant renal masses and the characterization of different malignant categories, subtypes and grades.
Diffusion-weighted MR imaging in the evaluation of renal tumours
Journal of experimental & clinical cancer research : CR, 2004
The aim of this study was to evaluate the capability and the reliability of diffusion-weighted MR imaging to differentiate benign from malignant renal lesions. Twenty healthy volunteers and 48 patients with known renal lesions underwent MR of the kidneys by using a 1.5 T superconductive magnet. Diffusion-weighted images (DWI) were obtained on the axial plane during breathhold (17 s) with a SE EPI single shot sequence using a b value of 500 s/mm2. One region of interest (ROI) (lesions < than 3 cm) or 3 ROI (lesions > than 3 cm) were placed within the lesion for the measurement of apparent diffusion coefficient (ADC). ADC map was obtained at each slice position. Mean ADC value in normal renal parenchyma was 2.2 +/- 0.20 x 10(-3) mm2/s, while ADC values in simple cysts (n = 20) were higher (mean ADC values 3.65 +/- 0.09 x 10(-3) mm2/s). Solid benign and malignant renal tumors (n = 19) showed a mean ADC value of 1.7 +/- 0.48 x 10(-3) mm2/sec. The comparison between ADC values in n...
Balkan Medical Journal, 2015
Background: Diffusion-weighted magnetic resonance imaging (DWI) is a widely-accepted diagnostic modality whose efficacy has been investigated by numerous past studies in the differentiation of malignant lesions from benign entities. Aims: The aim of this study was to evaluate the efficiency of diffusion-weighted magnetic resonance imaging in the characterization of renal lesions. Study Design: Diagnostic accuracy study. Methods: A total of 137 patients with renal lesions were included in this study. The median apparent diffusion coefficient (ADC) values as well as the b 800 and b 1600 signal intensities of normal kidneys, solid components of mixed renal masses, and total cystic lesions were evaluated. Results: There were significant differences between the ADC values of lesions and normal renal parenchyma, and between the ADC values of benign and malignant renal lesions on DWIs at b values of 800 and 1600 s/mm² (p<0.001 and p<0.001, respectively). There were significant differences between the ADC values of Bosniak Category 1 and 2 cysts and the ADC values of Bosniak Category 1 and 3 cysts on DWIs at b values of 800 s/mm² (p<0.001) and 1600 s/mm 2 (p<0.001). A cutoff value of 1.902 x 10-3 mm²/s for the ADC with a b value of 800 s/mm² provided 88% sensitivity and 96% specificity for differentiation between benign and malignant renal lesions. A cutoff value of 1.623 x 10-3 mm²/s for the ADC with a b value of 1600 s/mm² provided 79% sensitivity and 96% specificity (p<0.001) for the differentiation between benign and malignant renal lesions. Conclusion: Accurate assessment of renal masses is important for determining the necessity for surgical intervention. DWI provides additional value by differentiating benign from malignant renal tumors and can be added to routine kidney MRI protocols.
Correlation of diffusion-weighted MR imaging with cellularity of renal tumours
Anticancer research
Diffusion is a physical process based on the random movement of water molecules known as Brownian movement. Diffusion-weighted imaging (DWI) is a magnetic resonance (MR) technique that provides information about the biophysical properties of tissues such cell organization and density, microstructure and microcirculation. Twenty healthy volunteers and 18 patients with renal tumor were enrolled in our study. The DWI was obtained before contrast media injection with a single-shot SE EPI Inversion Recovery (IR) sequence. The tumor cellularity of each resected lesion was evaluated. The mean apparent diffusion coefficient (ADC) value of renal tumors was significantly lower than the mean ADC value of normal renal parenchyma. In our series, the mean ADC value of renal tumors did not significantly correlate with tumor cellularity, but correlated with histological architecture. These preliminary results indicate the utility of DWI in the acquisition of tissue characterization data of renal ma...