title: Perinephric hematoma: semi-automated quantification of volume on MDCT: a feasibility study.
abstract: BACKGROUND
  To evaluate feasibility and reproducibility of quantification of perinephric hematoma volume on multidetector-row CT (MDCT).
  
  
  METHODS
  Perinephric hematomas in 63 patients (42 males, 21 females, median age: 49 years) imaged with contrast-enhanced MDCT of the abdomen were evaluated. A semi-automated segmentation software was applied to quantify hematoma volume. Reproducibility for quantification of hematoma volume was evaluated by repeated measurements in 20 patients. Statistical analyses were performed by using Student's t test. Interobserver and intraobserver variability was evaluated by Bland-Altman plots. P < 0.05 denoted statistical significance
  
  
  RESULTS
  Quantification of hematoma volume was feasible in all cases. One step, direct quantification of volume was possible in 21 patients (33.33%) with small hematomas that did not reach upper and lower renal poles (range: 3.12-183.98 mL; mean: 39.92 mL). Quantification of hematoma size was performed indirectly in 42 patients (66.67%) with larger hematomas that extended beyond the renal poles by subtracting the ipsilateral renal volume from the combined kidney and hematoma volumes (range: 27.08-2431.3 mL; mean: 435.31 mL). Mean quantification time was 45 and 71 s for small and large hematomas, respectively (P < 0.05). Mean intraobserver and interobserver variability for determination of hematoma volume was 0.14% (95% CI, -1.57% to 1.85%) and 2.04% (95% CI, -1.77% to 5.85%), respectively. There was no significant difference in renal volume between ipsilateral and contralateral kidneys (P > 0.05).
  
  
  CONCLUSIONS
  Quantification of perinephric hematoma was feasible from MDCT data in all patients and was reproducible.
authors.affiliation: Department of Radiology, Northwestern University-Feinberg School of Medicine, Chicago, IL, USA.
authors.forename: Pedram
authors.initials: P
authors.lastname: Rezai
authors.forename: Sandra
authors.initials: S
authors.lastname: Tochetto
authors.forename: Mauricio
authors.initials: M
authors.lastname: Galizia
authors.forename: Vahid
authors.initials: V
authors.lastname: Yaghmai
mesh_terms: D000007:Abdominal Injuries / Q000150:complications; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D005240:Feasibility Studies; D005260:Female; D006406:Hematoma / Q000000981:diagnostic imaging*; D006801:Humans; D007472:Iohexol; D007668:Kidney / Q000293:injuries; D007674:Kidney Diseases / Q000000981:diagnostic imaging* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D010363:Pattern Recognition, Automated / Q000379:methods; D015203:Reproducibility of Results; D012984:Software; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D007472:Iohexol