title: Influence of CT-based attenuation correction in assessment of left and right ventricular functions with count-based gated blood-pool SPECT.
abstract: OBJECTIVE
  Influence of CT-based attenuation correction (CT-AC) in assessment of left and right ventricular functions with count-based gated blood-pool SPECT (GBPS) was evaluated in a mixed population.
  
  
  METHODS
  Thirty-two patients (81% male; mean age 56 ± 12) referred for various symptoms or heart diseases were prospectively included. Data from 32 GBPS acquisitions were reconstructed using an iterative algorithm with (IRAC) and without (IRNC) CT-AC and analyzed using previously described segmentation software based on the watershed algorithm. LV and RV EF and volumes were assessed with and without CT-AC and compared.
  
  
  RESULTS
  EF and volumes were correlated (P < .001 for all parameters with r = 0.97 for LV and RV EF; r = 0.96 for LV EDV; r = 0.98 for LV ESV; r = 0.96 for RV EDV and ESV). The mean values using IRAC and IRNC were different for all parameters with lower EF (respectively, 49% ± 19% vs 51 %± 18%; P = .002 for LV EF and 50% ± 14% vs 54%±15%; P < .001 for RV EF) and higher volumes (respectively, 142 ± 41 mL vs 133 ± 40 mL; P < .001 and 79 ± 45 mL vs 71 ± 42 mL; P < .001 for LV EDV and ESV; 91 ± 32 mL vs 86 ± 31 mL; P = .003 and 48 ± 28 mL vs 43 ± 26 mL; P < .001 for RV EDV and ESV). Limits of agreement were -11% to 6% and -11% to 4% for LV and RV EF. We found wider limits of agreement for LV volumes (-13 to 32 mL for EDV and -10 to 27 mL for ESV) than for RV volumes (-13 to 23 mL for EDV and -9 to 20 mL for ESV). Taking into account all volumes, we found a trend with a significant positive correlation between means and differences in volumes assessed with and without CT-AC.
  
  
  CONCLUSIONS
  Assessment of both left and right ventricular functions by count-based GBPS with CT-AC showed higher volumes and lower EF. Differences were slight, especially for the range of normal to subnormal ventricular volumes.
authors.affiliation: Department of Nuclear Medicine, CHRU Lapeyronie, 371 Av. du Doyen Gaston Giraud, 34295, Montpellier, France. louis.sibille@gmail.com
authors.forename: Louis
authors.initials: L
authors.lastname: Sibille
authors.forename: Fayçal Ben
authors.initials: FB
authors.lastname: Bouallegue
authors.forename: Aurélie
authors.initials: A
authors.lastname: Bourdon
authors.forename: Denis
authors.initials: D
authors.lastname: Mariano-Goulart
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D015637:Gated Blood-Pool Imaging / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013318:Stroke Volume; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016277:Ventricular Function, Left; D016278:Ventricular Function, Right