title: Technetium-99m sestamibi cavity/myocardium count ratio in the detection of left ventricular hypertrophy.
abstract: OBJECTIVE
  Left ventricular hypertrophy (LVH) is an independent risk factor for cardiovascular mortality and morbidity. This study was designed to assess whether technetium-99m (99mTc) sestamibi cavity-to-myocardium count (c/m) ratio would differentiate LVH from normal geometry, and discriminate between the two patterns-concentric and eccentric--of LVH.
  
  
  METHODS
  In all, 72 patients including 32 hypertensive patients with both normal 99mTc sestamibi single-photon emission computed tomography imaging and good-quality echocardiographic recordings were studied retrospectively. Four different patterns of left ventricular (LV) geometry were defined: normal (n = 47), concentric remodeling (n = 3), eccentric LVH (n = 13), and concentric LVH (n = 9).
  
  
  RESULTS
  Left ventricular hypertrophy was detected in 22 of 32 hypertensive patients. The c/m ratio calculated on midventricular short-axis slices of dipyridamole-stress 99mTc sestamibi images was significantly decreased in patients with LVH compared with subjects with normal geometry (0.05 +/- 0.02 vs. 0.17 +/- 0.08, p = 0.001). A c/m ratio of <0.124 yielded a sensitivity of 86%, a specificity of 64%, and an overall diagnostic accuracy of 68% for detecting LVH. Negative correlations of c/m ratio were found to LV mass-index (r = -0.44, p = 0.004), septal width (r = -0.42, p = 0.008), posterior wall thickness (r = -0.39, p = 0.001), and relative wall thickness (r = -0.40, p = 0.001). Multiple linear regression analysis revealed that LV mass index was the single independent predictor of c/m ratio. Although both groups with concentric and eccentric LVH had a significantly lower mean c/m ratio than those with normal geometry (p = 0.01 and p = 0.01, respectively), no significant difference of c/m ratio was found between the two patterns of LVH.
  
  
  CONCLUSIONS
  A new index, c/m ratio on 99mTc sestamibi images, has a potential to discriminate between LVH and normal geometry in subjects free of myocardial ischemia.
authors.affiliation: Trakya University, Faculty of Medicine, Department of Nuclear Medicine, Edirne, Turkey. gdurmusaltun@trakya.edu.tr
authors.forename: Gulay Durmus
authors.initials: GD
authors.lastname: Altun
authors.forename: Osman
authors.initials: O
authors.lastname: Akdemir
authors.forename: Funda
authors.initials: F
authors.lastname: Ustun
authors.forename: Armagan
authors.initials: A
authors.lastname: Altun
authors.forename: Ali
authors.initials: A
authors.lastname: Sarikaya
authors.forename: Sakir
authors.initials: S
authors.lastname: Berkarda
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging* / Q000503:physiopathology; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011336:Probability; D011446:Prospective Studies; D012016:Reference Values; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D012737:Sex Factors; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
chemical_list: D017256:Technetium Tc 99m Sestamibi