<p><b>BACKGROUND: </b>Our understanding of the pathophysiologic processes underlying sickle cell nephropathy remains incomplete. We performed a pilot study to investigate the potential value of magnetic resonance imaging (MRI) for the assessment of kidney oxygenation and detection of potential changes to tissue perfusion and cellular integrity during a vaso-occlusive crisis.</p><p><b>STUDY DESIGN: </b>A case-control study.</p><p><b>SETTING & PARTICIPANTS: </b>10 homozygous patients with sickle cell disease (SCD), without kidney disease (based on estimated glomerular filtration rate and albuminuria), underwent renal MRI during a vaso-occlusive crisis episode. The imaging data obtained were compared with those for a second MRI performed at steady state (median, 56 [IQR, 37-72] days after the vaso-occlusive crisis MRI). The control group consisted of 10 apparently healthy individuals.</p><p><b>MEASUREMENTS: </b>Deoxyhemoglobin level assessed by R2* value was calculated using the blood oxygen level-dependent technique. The intravoxel incoherent motion diffusion-weighted imaging technique was used to calculate D, D*, and F parameters.</p><p><b>RESULTS: </b>Median medullary R2* values on steady-state MRI were significantly higher for patients with SCD than for controls (P=0.01) and did not change significantly during the vaso-occlusive crisis. No significant differences in median cortical R2* values were observed. Both cellular integrity (D) and local perfusion (D* and F) were significantly altered in medullary and cortical areas during vaso-occlusive crises in comparison to steady state in patients with SCD. These parameters did not differ significantly between patients with SCD assessed at steady state and the control group.</p><p><b>LIMITATIONS: </b>Small sample size, estimation of glomerular filtration rate according to CKD-EPI creatinine equation without adjustment for race.</p><p><b>CONCLUSIONS: </b>Deoxyhemoglobin levels in the medullary area are higher in patients with SCD, during vaso-occlusive crises and at steady state, than in controls. Alterations to the tissue perfusion and cellular integrity of renal parenchyma are a common finding during vaso-occlusive crises that provide additional evidence that a vaso-occlusive crisis may be associated with subclinical kidney injury detectable on MRI.</p>
Magnetic Resonance Imaging Assessment of Kidney Oxygenation and Perfusion During Sickle Cell Vaso-occlusive Crises.
Am J Kidney Dis. 2017;69(1):51-59.
MeSH terms: Adult; Anemia, Sickle Cell; Case-Control Studies; Female; Humans; Kidney; Magnetic Resonance Imaging; Male; Oxygen; Pilot Projects; Regional Blood Flow; Young Adult