Technetium(99mTc) Tetrofosmin

This study was approved by the Johns Hopkins Institutional Review Board and all patients signed written, informed consent. Enrolled patients were categorised into two cohorts, comprising a total of 11 subjects.Cohort A consisted of four patients with previously biopsied renal masses demonstrating ′oncocytic neoplasm′. Cohort B consisted of seven patients with cT1 renal masses scheduled to undergo resection.The exclusion criteria prohibited pregnant patients, those with a history of other malignancy with concern for renal metastasis, or those with any known allergy to technetium or tetrofosmin.Patients were asked to be nil per os for approx. 6 h prior to radiotracer injection.Patients were placed supine on the scanner table, 75 min after the i.v. injection of 925 37 MBq (25 1 mCi) of 99mTc-tetrofosmin.A Symbia 16-slice or Intevo 16-slice single-photon emission CT (SPECT)/CT gamma camera (Siemens Healthineers, Erlangen, Germany) were used for all imaging procedures.SPECT imaging was acquired in step and shoot mode, with 25 s per image, utilizing 3 degrees per step over 120 steps and a detector range of 180 degrees per detector.CT images were acquired at 110 kV and 200 mAs with dose care modulation enabled. Images were reconstructed using a 128 9 128-pixel matrix, and the imaging field was focused on the abdomen between the diaphragm and the tops of the iliac crests; 3-mm axial images were reconstructed for both SPECT and CT imaging.

Myocardial perfusion imaging (MPI) provides physiologic and functional information about the heart muscle and its blood flow. Extracardiac radioactivity can interfere with visualization of the inferior wall of the myocardium, leading to poor-quality images, difficulties in interpretation, and delays in routine practice. This study aimed to identify the efficiency of having the patient consume a carbonated lemon drink to minimize the extracardiac radioactivity of ^99mTc-sestamibi in comparison to ^99mTc-tetrofosmin during MPI. Methods: This was a retrospective study that recruited 158 patients with known or suspected coronary artery disease referred to undergo ^99mTc-sestamibi or ^99mTc-tetrofosmin rest/stress single-day MPI. The patients were divided into 2 groups of mixed sexes and different ages. The first group comprised 78 patients injected with ^99mTc-sestamibi, and the second group comprised 80 patients injected with ^99mTc-tetrofosmin. For both groups, the patients drank 30 mL of fresh lemon juice diluted with 150 mL of soda water, and then we gave the patients about 100 mL of straight soda water, before imaging for both the rest and the stress phases. Results: Generally, in both groups, the ^99mTc-tetrofosmin produced a good-quality image in comparison with the ^99mTc-sestamibi. The mean rank of the total score for ^99mTc-tetrofosmin (62.75) was less than that for ^99mTc-sestamibi (96.68), and this difference was highly statistically significant (P = 0.000). There were statistically significant differences in the ratios and mean ranks for both groups in favor of ^99mTc-tetrofosmin in patients having coronary artery disease. Conclusion: The use of a carbonated lemon drink minimizes extracardiac activity from both ^99mTc-labeled MPI radiopharmaceuticals. This finding was more statistically significant for ^99mTc-tetrofosmin MPI, providing better image quality and earlier imaging in both the rest and the stress phases because of faster hepatobiliary clearance.