title: Usefulness of measuring coronary lumen density with multi-slice computed tomography to detect in-stent restenosis.
abstract: BACKGROUND
  A method to objectively detect in-stent restenosis (ISR) with multi-slice computed tomography (MSCT) has not been established yet. We aimed to evaluate the usefulness of measuring coronary lumen density with MSCT to detect ISR.
  
  
  METHODS
  Forty-seven coronary stented lesions in 38 patients were evaluated with 16-slice CT (collimation thickness, 0.625 mm). In each assessable lesion, the stent lumen was visually evaluated, and reference CT density proximal to the stent (RCTD) and minimum CT density of the in-stent lumen (SCTD) were measured. ISR was defined as >50% diameter stenosis measured by quantitative coronary angiography (QCA).
  
  
  RESULTS
  Of 47 stented lesions, 35 (74%) were assessable, and there were 12 ISR (+) and 23 ISR (-) lesions. Mean DeltaCTD (RCTD-SCTD) of the ISR (+) group was significantly greater than that of the ISR (-) group (196+/-101 vs. 7+/-30 HU, p<0.001). Predictive accuracy of quantitative evaluation of ISR using our best cutoff value of DeltaCTD was higher than that of visual evaluation (97% vs. 83%, p<0.05). The DeltaCTD showed a higher correlation with percent diameter stenosis (r=0.85, p<0.001) than with SCTD (r=-0.73, p<0.001).
  
  
  CONCLUSIONS
  Measuring differences of CT densities between reference vessel lumens and in-stent lumens using MSCT is a convenient and useful technique to detect ISR.
authors.forename: Toshiro
authors.initials: T
authors.lastname: Kitagawa
authors.forename: Hideya
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Jun
authors.initials: J
authors.lastname: Horiguchi
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Hirai
authors.forename: Takashi
authors.initials: T
authors.lastname: Fujii
authors.forename: Katsuhide
authors.initials: K
authors.lastname: Ito
authors.forename: Nobuoki
authors.initials: N
authors.lastname: Kohno
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects / Q000379:methods; D016001:Confidence Intervals; D017023:Coronary Angiography / Q000379:methods; D023903:Coronary Restenosis / Q000000981:diagnostic imaging* / Q000453:epidemiology; D023921:Coronary Stenosis / Q000000981:diagnostic imaging / Q000628:therapy*; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011336:Probability; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D015607:Stents / Q000009:adverse effects*; D036542:Tomography, Spiral Computed / Q000379:methods*; D014654:Vascular Patency