Molecular imaging may be best for capturing renal transplant complications

"SPECT and CT fused images provide both functional and anatomical information about the kidney, which provides better diagnostic capability and greater confidence to our physicians," said Shashi Khandekar, administrator of the nuclear medicine department, Cleveland Clinic, Cleveland, Ohio. "We are becoming more technologically savvy and we strongly feel that as more and more clinicians use hybrid SPECT/CT imaging, technologists also need to be prepared and acquire all of the necessary qualifications for this technology."

The study combined SPECT and CT imaging techniques to provide an in-depth portrait of the biological processes of renal function. Traditionally, physicians have used two-dimensional planar imaging to evaluate post-renal transplant complications, which include urinary leak, infection and transplant non-viability or kidney failure. However, a recent retrospective study conducted by the Cleveland Clinic showed that three-dimensional SPECT/CT hybrid imaging is ideal for imaging these and other disease states. Employing SPECT/CT imaging may even answer clinical questions that could otherwise have led to further imaging studies, invasive biopsies and delayed treatment for the patient.

The retrospective study involved 12 renal transplant cases, in which 10 patients were suspected of having a urinary leak, one patient showed evidence of kidney failure and one patient was thought to have a transplant-associated infection. After traditional planar imaging, all patients were scanned using non-circular SPECT imaging and low dose non-contrast CT imaging using a hybrid SPECT/CT system. The use of SPECT/CT with Tc99m-MAG3, an imaging agent taken up by the kidneys and used to evaluate renal function, helped clinicians positively identify urinary leaks for 7 of the 10 patients when fused imaging revealed fluid outside the anatomical confines of the patients' urinary system. The molecular imaging technique was also able to successfully identify kidney failure using the same agent, and infection was detected in one patient injected with In-111 labeled WBC, an agent that helps image leukocyte activity associated with the body's immune response.

According to the National Kidney Foundation, 26 million Americans are currently living with chronic kidney disease. An estimated 16,520 renal transplants were conducted in 2008, and the number of kidney transplants occurring in the U.S. has risen 31 percent in the past decade. As of November 2009, more than 82,000 patients are on the national waiting list for a kidney transplant.

Scientific Paper 2002: S. Khandekar, D.R. Neumann, Nuclear Medicine, Cleveland Clinic, Cleveland, Ohio, "Utility of SPECT/CT in evaluating post renal transplant complications," presented at SNM's 57th Annual Meeting, June 5-9, 2010, Salt Lake City, Utah.