title: Assessment of viable myocardium by nitrate augmented 99mTc MIBI myocardial perfusion imaging.
abstract: OBJECTIVE
  To determine the efficacy of 99mTcMIBI with nitrate administration for the detection of viable myocardium in patients with MI.
  
  
  METHODS
  Thirty-five patients (31 men, 4 women; mean age 51.91 +/- 8.86 years, median = 50) with previous history of myocardial infarction (with mean duration of 11.50 +/- 11.4, median =4 months after MI) were included in the study. All patients underwent baseline rest and Nitroglycerine 99mTcMIBI myocardial perfusion imaging (2 day protocol). Fifteen out of 34 patients were also submitted for rest and redistribution TI-201 imaging (3 day protocol). The data were reconstructed in transaxial slices and then reoriented into short, vertical long and horizontal long axis slices. The images were divided into seven different segments for qualitative as well as semi quantitative analysis. The images were interpreted by two independent observers. The segments with tracer activity of more than 55% as compared to maximum, were considered as viable.
  
  
  RESULTS
  In the baseline study with 99mTcMIBI, 168/245 (68.57%) were viable segments and these were increased to 197 (80.40%) in the Nitrate MIBI study (p = 0.001 vs. baseline). Total 21 (60%) out of 35 patients demonstrated viable myocardium. The concordance for viable segments detection between Nitroglycerine MIBI and redistribution TI-201 imaging was found in 100 out of 105 segments (95.24%) for 15 patients, with significant kappa = 0.746 +/- 0.079 SE.
  
  
  CONCLUSIONS
  The data suggest that use of nitrate augmented 99mTcMIBI protocol in Cardiac SPECT imaging results in improved detection of viable but hypoperfused segments and achieves results similar to those from standard TI-201 rest and redistribution protocol.
authors: Karachi Institute of Radiotherapy and Nuclear Medicine, Karachi.
authors: Kashif
authors: K
authors: Niyaz
authors: Khalid
authors: K
authors: Niaz
authors: Maseeh Uz
authors: MU
authors: Zaman
authors: Shahid
authors: S
authors: Kamal
authors: Sharjeel
authors: S
authors: Usmani
authors: Salman
authors: S
authors: Habib
authors: Hina
authors: H
authors: Hashmi
authors: S Waqar
authors: SW
authors: Husssain
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005996:Nitroglycerin; D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi; D013794:Thallium Radioisotopes; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D019275:Radiopharmaceuticals; D013794:Thallium Radioisotopes; D017256:Technetium Tc 99m Sestamibi; D005996:Nitroglycerin