Functional evaluation of secondary renal amyloidosis with diffusion-weighted MR imaging

Abstract

Objectives This study evaluated whether diffusion-weighted magnetic resonance imaging (DW-MRI) can be used to diagnose secondary renal amyloidosis looking specifically at the diagnostic efficacy of two apparent diffusion coefficient (ADC) measurement methods as they were used with DW-MRI. Methods The study included 24 amyloid nephropathy (AN) patients, 20 chronic kidney disease (CKD) patients, and 20 healthy volunteers (HV). ADC values were measured using two different methods: 1) the method of the region of interest indicators (ROIs) and 2) the method of drawing whole renal parenchyma (WP). The correlation between the two methods was evaluated.Results ROIs could differentiate AN-CKD (p ¼ 0.007). ROIs and WP could differentiate AN-HV (p50.05). However, none of the methods could differentiate CKD-HV (p40.05). The sensitivity and specificity of the ROIs method in differentiating AN from CKD patients for 1.8 Â 10À3 cutoff ADC values were 79% and 60% and for AN-HV patients 79% and 70%. ADC values of AN patients with GFR460 mL/min were lower than that of HV (p50.01). Conclusion DW-MRI is a useful and noninvasive diagnostic tool in diagnosing secondary renal amyloidosis and differentiating renal amyloidosis from other CKDs. ROIs had the highest sensitivity and specificity for assessing the involvement of renal amyloidosis. MRI diagnosis of AN may obviate a renal biopsy for diagnosis. ARTICLE HISTORY

Noninvasive Diagnostics of Renal Amyloidosis: Current State and Perspectives

“…A major area of noninvasive diagnostics is the development of scanning research methods (radiography, computed tomography, ultrasound, magnetic resonance imaging, bone scintigraphy, and others). Currently, the application of those methods is limited to the late stages of amyloidosis in the presence of the significant deposition of amyloid aggregates in the organs [ 102 , 103 , 104 ]. Therefore, imaging is mainly applied to verify the amyloidosis diagnosis and clarify the type of amyloidosis.…”

“…While being effective for the detection of asymptomatic amyloid in some extra-renal organs, PET identified renal involvement in fewer subjects than the international consensus diagnostic approach was able to [ 108 ]. Research applying diffusion-weighted magnetic resonance imaging, which is sensitive to local water motion in the tissue, becomes more promising for the detection of amyloid nephropathy [ 102 ]. However, the sensitivity and specificity of that method in the detection of amyloidosis are still low (79% and 60%, respectively).…”

Amyloidoza nerek

“…Duże znaczenie u chorych z zajęciem serca mają diagnostyka obrazowa i badanie genetyczne. W większości przypadków amyloidozy badania obrazowe mają znaczenie jedynie pomocnicze, mimo że narządy, w których odkładają się złogi amyloidu, są powiększone i mają charakterystyczny obraz makroskopowy [51]. Wyjątkiem jest rozwijająca się w często w przebiegu ATTR (a także typu AL) amyloidoza serca, charakteryzująca się bardzo typowym obrazem echokardiograficznym.…”