Blood oxygen level-dependent and perfusion magnetic resonance imaging: detecting differences in oxygen bioavailability and blood flow in transplanted kidneys

• Published in: Magnetic resonance imaging Vol. 28; no. 1; pp. 56 - 64
• Main Authors: Sadowski, Elizabeth A., Djamali, Arjang, Wentland, Andrew L., Muehrer, Rebecca, Becker, Bryan N., Grist, Thomas M., Fain, Sean B.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Inc 01.01.2010; Elsevier
• Subjects: Aged; Biological and medical sciences; Blood flow; Blood Flow Velocity; BOLD; Female; Humans; Kidney - blood supply; Kidney - physiopathology; Kidney Transplantation; Magnetic Resonance Angiography - methods; Medical sciences; Middle Aged; Oxygen - blood; Oxygen bioavailability; Perfusion MRI; Radiology; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Reproducibility of Results; Sensitivity and Specificity; Technology. Biomaterials. Equipments. Material. Instrumentation; Transplanted kidneys; Young Adult; BOLD; Perfusion MRI; Oxygen bioavailability; Blood flow; Transplanted kidneys; Nuclear magnetic resonance imaging; Biomedical engineering
• ISSN: 0730-725X; 1873-5894; 1873-5894
• DOI: 10.1016/j.mri.2009.05.044

Functional magnetic resonance imaging (fMRI) is a powerful tool for examining kidney function, including organ blood flow and oxygen bioavailability. We have used contrast enhanced perfusion and blood oxygen level-dependent (BOLD) MRI to assess kidney transplants with normal function, acute tubular necrosis (ATN) and acute rejection. BOLD and MR-perfusion imaging were performed on 17 subjects with recently transplanted kidneys. There was a significant difference between medullary R2⁎ values in the group with acute rejection (R2⁎=16.2/s) compared to allografts with ATN (R2⁎=19.8/s; P=.047) and normal-functioning allografts (R2⁎=24.3/s;P=.0003). There was a significant difference between medullary perfusion measurements in the group with acute rejection (124.4±41.1 ml/100 g per minute) compared to those in patients with ATN (246.9±123.5 ml/100 g per minute; P=.02) and normal-functioning allografts (220.8±95.8 ml/100 g per minute; P=.02). This study highlights the utility of combining perfusion and BOLD MRI to assess renal function. We have demonstrated a decrease in medullary R2⁎ (decrease deoxyhemoglobin) on BOLD MRI and a decrease in medullary blood flow by MR perfusion imaging in those allografts with acute rejection, which indicates an increase in medullary oxygen bioavailability in allografts with rejection, despite a decrease in blood flow.