Since renal parenchymal disease is accompanied by renal dysfunction, monitoring renal function permits assessment of disease progression, and periodic assessment of renal function is necessary for optimal management of a patient with suspected/proven renal disease. Serum creatinine (S Cr), blood urea (BU), and estimated glomerular filtration rate (eGFR) derived from creatinine clearance are useful for monitoring renal function; however, these indirect measures of renal filtration are imperfect and cannot assess single kidney function.
Keeping in view the limitations of serum markers, imaging may play an important role in the evaluation of renal parenchymal disease. Ultrasonography (US) and computed tomographic (CT) scan provide good anatomic images but limited functional information. Although US may show changes in renal echogenicity, it suffers from operator dependency and lacks objectivity. In addition to exposure to ionizing radiation, computed tomography (CT) scan requires use of iodinated contrast material, which is undesirable in patients with renal dysfunction. Magnetic resonance imaging (MRI) has the unique ability to show both structure and function objectively without any radiation exposure to the patient. Functional MRI techniques such as diffusion-weighted imaging (DWI), blood oxygen level-dependent (BOLD) imaging have potential utility in the evaluation of renal function .
