title: Low-dose single acquisition rest (99m)Tc/stress (201)Tl myocardial perfusion SPECT protocol: phantom studies and clinical validation.
abstract: OBJECTIVE
  We developed and tested a single acquisition rest (99m)Tc-sestamibi/stress (201)Tl dual isotope protocol (SDI) with the intention of improving the clinical workflow and patient comfort of myocardial perfusion single photon emission computed tomography (SPECT).
  
  
  METHODS
  The technical feasibility of SDI was evaluated by a series of anthropomorphic phantom studies on a standard SPECT camera. The attenuation map was created by a moving transmission line source. Iterative reconstruction including attenuation correction, resolution recovery and Monte Carlo simulation of scatter was used for simultaneous reconstruction of dual tracer distribution. For clinical evaluation, patient studies were compared to stress (99m)Tc and rest (99m)Tc reference images acquired in a 2-day protocol. Clinical follow-up examinations like coronary angiography (CAG) and fractional flow reserve (FFR) were included in the assessment if available.
  
  
  RESULTS
  Phantom studies demonstrated the technical feasibility of SDI. Artificial lesions inserted in the phantom mimicking ischaemia could be clearly identified. In 51/53 patients, the image quality was adequate for clinical evaluation. For the remaining two obese patients with body mass index > 32 the injected (201)Tl dose of 74 MBq was insufficient for clinical assessment. In answer to this the (201)Tl dose was adapted for obese patients in the rest of the study. In 31 patients, SDI and (99m)Tc reference images resulted in equivalent clinical assessment. Significant differences were found in 20 patients. In 18 of these 20 patients additional examinations were available. In 15 patients the diagnosis based on the SDI images was confirmed by the results of CAG or FFR. In these patients the SDI images were more accurate than the (99m)Tc reference study. In three patients minor ischaemic lesions were detected by SDI but were not confirmed by CAG. In one of these cases this was probably caused by pronounced apical thinning. For two patients no relevant clinical follow-up information was available for evaluation.
  
  
  CONCLUSIONS
  The proposed SDI protocol has the potential to improve clinical workflow and patient comfort and suggests improved accuracy as demonstrated in the clinical feasibility study.
authors.affiliation: Institute of Imaging & Computer Vision, RWTH Aachen University, Aachen, Germany, thomas.dey@lfb.rwth-aachen.de.
authors.forename: Thomas
authors.initials: T
authors.lastname: Dey
authors.forename: Barbra E
authors.initials: BE
authors.lastname: Backus
authors.forename: R Leo
authors.initials: RL
authors.lastname: Romijn
authors.forename: Herfried
authors.initials: H
authors.lastname: Wieczorek
authors.forename: J Fred
authors.initials: JF
authors.lastname: Verzijlbergen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D019047:Phantoms, Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D017256:Technetium Tc 99m Sestamibi / Q000493:pharmacokinetics; D013793:Thallium / Q000493:pharmacokinetics; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
chemical_list: D019275:Radiopharmaceuticals; C027549:thallium chloride; D017256:Technetium Tc 99m Sestamibi; D013793:Thallium
references.citation: J Nucl Med. 1989 Mar;30(3):301-11
references.pmid: 2525610
references.citation: J Nucl Med. 1994 Apr;35(4):542-8
references.pmid: 8151372
references.citation: Nucl Med Commun. 2010 Jun;31(6):539-46
references.pmid: 20429095
references.citation: Int J Mol Imaging. 2012;2012:695632
references.pmid: 23213515
references.citation: J Nucl Med. 2006 Oct;47(10):1662-9
references.pmid: 17015903
references.citation: Ann ICRP. 2008;38(1-2):1-197
references.pmid: 19154964
references.citation: IEEE Trans Med Imaging. 2002 Aug;21(8):867-77
references.pmid: 12472260
references.citation: J Nucl Med. 1993 Aug;34(8):1254-9
references.pmid: 8326381
references.citation: Ann Nucl Med. 1994 Nov;8(4):277-81
references.pmid: 7702973
references.citation: Phys Med Biol. 2011 Jul 21;56(14):R85-112
references.pmid: 21701055
references.citation: J Nucl Cardiol. 2001 Mar-Apr;8(2):182-7
references.pmid: 11295696
references.citation: J Nucl Cardiol. 1998 May-Jun;5(3):265-74
references.pmid: 9669581
references.citation: IEEE Trans Med Imaging. 1991;10(3):408-12
references.pmid: 18222843
references.citation: Circulation. 1981 Sep;64(3):610-8
references.pmid: 7261290
references.citation: J Nucl Med. 1993 Dec;34(12):2216-21
references.pmid: 8254414
references.citation: J Nucl Cardiol. 2004 Jan-Feb;11(1):47-52
references.pmid: 14752472
references.citation: J Nucl Med. 1997 Mar;38(3):428-32
references.pmid: 9074532
references.citation: Phys Med Biol. 1999 Jul;44(7):1843-60
references.pmid: 10442716