ABSTRACT
AIM: To describe the appearance of small solid renal lesions (≤3 cm) on diffusion-weighted magnetic resonance imaging (MRI) and to determine whether ADC measurements may help to differentiate benign from malignant small solid renal masses. METHODS AND MATERIALS: Thirty-five patients with 47 small renal masses (23 malignant, 24 benign) who underwent 3 T MRI of the kidney using diffusion-weighted sequences (b values of 0 and 1000 s/mm(2)) were retrospectively evaluated. Qualitative and quantitative analysis of diffusion-weighted images was performed. RESULTS: Most lesions were hyperintense to kidney on high b-value diffusion-weighted images and hypointense on apparent diffusion coefficient (ADC) map. The mean ADC of the lesions was significantly lower than that of kidney (1.22 ± 0.3 versus 1.85 ± 0.12 mm(2)/s; p < 0.005). The mean ADC was significantly different between renal cell carcinomas (1.2 ± 0.01 mm(2)/s), metastases (1.25 ± 0.04 mm(2)/s), angiomyolipoma (1.07 ± 0.3 mm(2)/s) and oncocytomas (1.56 ± 0.08 mm(2)/s; p < 0.05). The mean ADC of clear cell renal cell carcinomas was significantly different from that of non-clear cell renal cell carcinomas (1.38 ± 0.34 versus 0.83 ± 0.34 mm(2)/s; p < 0.005). No significant difference was found between mean ADC of fat containing and minimal fat angiomyolipomas (1.06 ± 0.48 versus 1.11 ± 0.33 mm(2)/s). CONCLUSION: Small solid renal masses are hyperintense on high b value and have different ADC values.
Subject(s)
Diffusion Magnetic Resonance Imaging , Kidney Neoplasms/diagnosis , Adult , Aged , Aged, 80 and over , Diffusion Magnetic Resonance Imaging/methods , Female , Humans , Image Processing, Computer-Assisted , Kidney/pathology , Kidney Neoplasms/pathology , Male , Middle AgedABSTRACT
AIM: Evaluate diffusion MRI in the multiparametric assessment of prostate cancer before needle biopsy. MATERIALS AND METHODS: One hundred eleven patients with suspected prostate cancer (mean age: 63 years old, median PSA: 7 ng/mL) were examined before undergoing needle biopsy (59 patients with a history of a negative biopsy and 52 without a history of biopsy). A diffusion sequence type SS SE-EPI (TR/TE: 5357/58, fEPI: 73, b 0 and 1000 s/mm², axial) with a qualitative analysis of the ADC map was performed in addition to T2 and T1 gadolinium enhanced sequences on 3 T MRI with an endorectal coil. The histological correlations were obtained by ultrasound guided needle biopsy (85 patients) or radical prostatectomy (26 patients). RESULTS: The correlation of the results of the diffusion sequence in the series of the 111 patients and the biopsies of the entire prostate or the hemiprostate had a sensitivity of: 92%, 77%; a specificity of: 55%, 70%; a positive predictive value of: 77%, 62%; a negative predictive value of: 84%, 80% and an efficacy of 78%, 75% respectively. The agreement of the three sequences had a specificity of 84.3%. CONCLUSION: The sensitivity of diffusion MRI is high for the detection of cancer of the prostate. Specificity of sequences is good. The results of simple visual assessment of the ADC map are good.
Subject(s)
Biopsy, Needle , Diffusion Magnetic Resonance Imaging , Image Processing, Computer-Assisted , Prostatic Neoplasms/diagnosis , Aged , Biomarkers, Tumor/blood , Cohort Studies , Contrast Media/administration & dosage , Endosonography , Gadolinium , Humans , Male , Middle Aged , Neoplasm Invasiveness , Neoplasm Staging , Prostate/pathology , Prostate-Specific Antigen/blood , Prostatectomy , Prostatic Neoplasms/pathology , Sensitivity and Specificity , Ultrasonography, InterventionalABSTRACT
After being first used for liver imaging, diffusion-weighted imaging of the kidney is in development. The kidney is the only anisotropic organ in the abdomen. It is a complex organ, with different types of flow, that is the subject of multiple research projects. Diffusion-weighted imaging is very sensitive for the detection of tumors, especially small ones. It also facilitates lesion characterization with the help of ADC values. Diffusion restriction indicates hypercellularity, which suggests malignancy. Diffusion-weighted imaging is currently available on clinical scanners. Characterization of different types of collections is possible. The characterization of nephropathies remains investigational.
