Clinical Question: Can we assess a myocardial perfusion and renal function simultaneously during 99m-Tc gated SPECT myocardial perfusion scanning?

Background: Cardiac function is closely related to renal function. Decreased function of one system often leads to decreased functioning in the other. The assessment of renal and cardiac function during a single study is thus appealing from a clinical standpoint. In addition, since both would be assessed after a single injection of the radioisotope, there would be a significant socioeconomic value.

Objectives: the objective of this study was to see if 99m-Tc tetrofosmin renal scintigraphy could be performed accurately (compared to Tc-99m DTPA renal scintigraphy) when don in conjunction with gated SPECT myocardial perfusion imaging. The study also looked at renal function after adenosine stress as compared to rest renal function.

Study Design: prospect evaluation of a cohort.

Participants: there were a total of 30 patients referred for clinical reasons for myocardial gated SPECT imaging. Of these, there were 24 with hypertension (including 7 with renovascular hypertension), 7 with diabetes, and 6 with dilated cardiomyopathy.

Methods: Gated SPECT stress-rest myocardial perfusion imaging was performed in standard fashion utilizing a two-day, single isotope protocol with Tc99m tetrofosmin. The next week, 24/30 patients had a standard dynamic Tc-99m DTPA renal scan for comparison with the rest Tc-99m tetrofosmin study.

The rest acquisition started out with planar dynamic and function renal imaging for 30 minutes. Then, gated SPECT myocardial perfusion images were obtained. Patient dosage of the Tc99m was about 10 mCi (370 MBq).

Stress cardiorenal imaging utilized adenosine stress testing. Renal images were acquired over 30 minutes, starting at 3 minutes into the adenosine infusion. Gating was performed using 16 frames per cardiac cycle.

The renal scans consisted of dynamic and functional imaging over 30 minutes. Values obtained included split renal function, time to peak uptake, and the uptake index for the radiotracer.

Results: On visual analysis, the renal images from Tc99m tetrofosmin were of higher quality due to the higher uptake index of tetrofosmin compared to DTPA. The split renal function as determined by 99m-Tc tetrofosmin was comparable to that obtained by Tc99m DTPA. Time to peak activity also was comparable for the two tracers.

Patients undergoing adenosine stress renal imaging overall had a statistically significant (p less than 0.005) drop in their 99m-Tc tetrofosmin uptake index as compared to the uptake index which was obtained by at rest.

Conclusion: renal function can be accurately assessed when done in conjunction with 99m-Tc tetrofosmin gated SPECT myocardial perfusion imaging and only requires a single injection of the isotope.

Source: J Nucl Med. 2009 Jul 17. [Epub ahead of print]. Single-Shot Cardiorenal Scintigraphy with 99mTc-Tetrofosmin: A Dynamic Characterization at Rest and During Adenosine Infusion. Fommei E, Bruselli L, Ripoli A, Gimelli A, Ghione S, Giorgetti A, Kush A, Tagliavia ID, Passino C, Marzullo P. “Gabriele Monasterio” Foundation, CNR Institute of Clinical Physiology, Pisa, Italy; Department of Internal Medicine, University of Pisa, Pisa, Italy. Abstract.

NuclearWiki

Just Launched:

NuclearWiki.com – the molecular imaging encyclopedia. This will be discussed at the 2009 SNM Annual Meeting in Toronto, Ontario