Diffusion tensor imaging MRI of sickle cell kidney disease: initial results and comparison with iron deposition

Abstract

Chronic kidney disease (CKD) occurs in over one-third of patients with sickle cell disease (SCD) and can progress to end-stage renal disease. Unfortunately, current clinical assessments of kidney function are insensitive to early-stage CKD. Previous studies have shown that diffusion magnetic resonance imaging (MRI) can sensitively detect regional renal microstructural changes associated with early-stage CKD. However, previous MRI studies in patients with SCD have been largely limited to the detection of renal iron deposition assessed by T * relaxometry. In this pilot imaging study, we compare MRI assessments of renal microstructure (diffusion) and iron deposition (T *) in patients with SCD and in non-SCD control subjects. Diffusion tensor imaging (DTI) and T * relaxometry MRI data were obtained for pediatric (n = 5) and adult (n = 4) patients with SCD, as well as for non-SCD control subjects (n = 10), on a Siemens Espree 1.5-T MRI scanner. A region-of-interest analysis was used to calculate mean medullary and cortical values for each MRI metric. MRI findings were also compared with clinical assessments of renal function and hemolysis. Patients with SCD showed a significant decrease in medullary fractional anisotropy (FA, p = 0.0001) in comparison with non-SCD subjects, indicative of microstructural alterations in the renal medulla of patients with SCD. Cortical and medullary reductions in T * (increased iron deposition, p = ≤0.0001) were also observed. Significant correlations were also observed between kidney T * assessments and multiple measures of hemolysis. This is the first DTI MRI study of patients with SCD to demonstrate reductions in medullary FA despite no overt CKD [estimated glomerular filtration rate (eGFR) > 100 mL/min/1.73 m ]. These medullary FA changes are consistent with previous studies in patients with CKD, and suggest that DTI MRI can provide a useful measure of kidney injury to complement MRI assessments of iron deposition.

Urine biomarkers of chronic kidney damage and renal functional decline in childhood-onset systemic lupus erythematosus

“…Unfortunately, our findings are in line with those of many other investigators that aimed at validating urine biomarkers of kidney damage [46]. Arguably, blood-based biomarkers [47], microRNAs reflecting renal fibrosis [48], and/or advanced kidney imaging strategies [49] might be better suited to capture abnormalities in renal mechanisms due to structural changes with LN chronicity.…”

Diffusion Tensor Imaging in early prediction of renal fibrosis in patients with renal disease: Functional and histopathological correlations

“…20,21 Medullary FA changes have been found as indicative of microstructural alterations in the renal medulla in patients with CKD and early nephropathy. 15,21,22 The results of the current study contradict this finding as it failed to identify a statistical difference of medullary FA between patients and controls and so in the other included comparisons. There were no reported correlations between medullary FA and the studied functional and histopathological variables.…”

“…While invasive biopsy is an available method for evaluation of RF, non‐invasive diagnostic tools are required to enhance the diagnostic and prognostic utility. Earlier studies have revealed that diffusion MRI can sensitively detect regional renal microstructural changes associated with early‐stage CKD 11,15 . Several MRI approaches are emerging to quantify fibrosis.…”

“…Earlier studies have revealed that diffusion MRI can sensitively detect regional renal microstructural changes associated with early-stage CKD. 11,15 Several MRI approaches are emerging to quantify fibrosis. T1 mapping and DWI are among the studied techniques.…”

Intravoxel incoherent motion imaging of the kidney: The application in patients with hyperuricemia

“…Currently, serum creatinine level, and creatinine‐based estimated glomerular filtration rate (eGFR) are the most common indicators of renal function in clinical practice. However, they suffer from limited sensitivity and specificity for early identification of impaired renal function . Renal biopsy is the reference standard for the accurate diagnosis of kidney diseases.…”