title: Technetium-99m-labelled HL91 and technetium-99m-labelled MIBI SPECT imaging for the detection of ischaemic viable myocardium: a preliminary study.
abstract: OBJECTIVE
  The assessment of myocardial viability has become an important aspect of the diagnostic and prognostic work-up of patients with coronary artery disease. Technetium-99m labelled sestamibi ((99m)Tc-MIBI) myocardial perfusion imaging may underestimate the viability of ischaemic myocardium. Technetium-99m labelled 4,9-diaza-3,3,10,10-tetramethyldodecan-2,11-dione dioxime ((99m)Tc-HL91) is a hypoxia-avid agent which can identify acutely ischaemic viable myocardium in a canine model using a standard gamma camera. The aim of this study was to evaluate uptake character of ischaemic viable myocardium and diagnostic performance of single-photon emission computed tomography (SPECT) imaging by (99m)Tc-HL91 and (99m)Tc-MIBI in detecting ischaemic viable myocardium in coronary heart disease.
  
  
  METHODS
  A total of 41 patients with coronary artery disease were recruited from March 2008 to May 2009. For detecting ischaemic viable myocardium, SPECT imaging by (99m)Tc-HL91 and (99m)Tc-MIBI were performed in all patients before coronary revascularization. Six patients with single ischaemic myocardial segment received a 2-day SEPCT/CT imaging protocol and the uptake of (99m)Tc-HL91 in ischaemic myocardium was quantitatively analysed. The remaining 35 patients received a 1-day (99m)Tc-HL91 and (99m)Tc-MIBI SPECT imaging protocol. Resting (99m)Tc-MIBI myocardial perfusion imaging in 3-18 months after revascularization was used as the standard methodology to evaluate the myocardial viability.
  
  
  RESULTS
  In 41 patients, 66 ischaemic myocardial segments were proven to be viable and 12 to be necrotic by resting (99m)Tc-MIBI myocardial perfusion imaging after coronary revascularization. Furthermore, 60 viable segments with negative uptake of (99m)Tc-MIBI showed positive uptake of (99m)Tc-HL91. The remaining six viable segments and 12 necrotic segments showed both negative uptake of (99m)Tc-HL91 and (99m)Tc-MIBI. The sensitivity, specificity, accuracy, Younden Index, positive predictive value and negative predictive value for evaluating ischaemic viable myocardium were 90·9%, 100%, 92·3%, 90·9%, 100% and 66·7%, respectively. Ischaemic viable myocardium had the negative (99m)Tc-MIBI uptake and positive (99m)Tc-HL91 uptake, which demonstrated a mismatched uptake character. Quantitative analysis indicated the uptake of (99m)Tc-HL91 in viable myocardium was increasing in the first 1-3 h and remained stable at the 3-4 h after injection.
  
  
  CONCLUSIONS
  Functional SPECT imaging with (99m)Tc-HL91 and (99m)Tc-MIBI can be used to detect the seriously ischaemic but viable myocardium with a mismatched uptake character. The uptake of (99m)Tc-HL91 in the viable myocardium reached a stable level at 3-4 h after injection.
authors.affiliation: Department of Radiology, Imaging Center, Chao Yang Hospital of Capital Medical University, Beijing, China. mikie0763@126.com
authors.forename: Min
authors.initials: M
authors.lastname: Liu
authors.forename: Zhanhong
authors.initials: Z
authors.lastname: Ma
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Guo
authors.forename: Jianguo
authors.initials: J
authors.lastname: Zhu
authors.forename: Jun
authors.initials: J
authors.lastname: Su
mesh_terms: D000368:Aged; D002681:China; D003326:Coronary Circulation; D003327:Coronary Disease / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D009206:Myocardium / Q000473:pathology*; D015609:Organotechnetium Compounds; D010091:Oximes; D010865:Pilot Projects; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi; D013997:Time Factors; D014022:Tissue Survival; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D015609:Organotechnetium Compounds; D010091:Oximes; D019275:Radiopharmaceuticals; C105527:technetium Tc 99m 4,9-diaza-3,3,10,10-tetramethyldodecan-2,11-dione dioxime; D017256:Technetium Tc 99m Sestamibi