title: Value of "patent track" sign on Doppler sonography after percutaneous liver biopsy in detection of postbiopsy bleeding: a prospective study in 352 patients.
abstract: OBJECTIVE
  The purpose of our study was to determine the prevalence of the "patent track" sign on Doppler sonography after percutaneous liver biopsy and to assess its value in detection of postbiopsy bleeding.
  
  
  METHODS
  The study group included 352 patients who underwent Doppler sonography after 361 percutaneous liver biopsies. Color-flow images were obtained immediately and 5 minutes after the biopsies. Images were evaluated for the patent track sign, defined as linear color flow along the needle path. Patients were followed-up with clinical and laboratory findings to search for postbiopsy bleeding. Those suspected of having postbiopsy bleeding underwent CT. Sonographic results were compared with clinical and CT findings.
  
  
  RESULTS
  Clinically significant postbiopsy bleeding occurred in five patients (1%). On Doppler sonography immediately after the biopsies, the patent track sign was seen in 43 patients (12%). Patients with this sign more frequently bled than those without it (p = 0.0008). Sensitivity, specificity, positive predictive values, and negative predictive values in detection of postbiopsy bleeding were 80%, 89%, 9%, and 100%, respectively. Among these patients, this sign was persistently seen in four and disappeared in the remaining 39 at 5 minutes after the biopsies. Patients with a persistent patent track sign more frequently bled than those without it (p < 0.0001). Sensitivity, specificity, positive predictive value, and negative predictive value were 60%, 100%, 75%, and 99%, respectively.
  
  
  CONCLUSIONS
  A patent track sign, frequently seen on Doppler sonography immediately after percutaneous liver biopsy, provides excellent screening for postbiopsy bleeding. This sign strongly predicts postbiopsy bleeding when persistently seen for 5 minutes.
authors.affiliation: Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Pungnap-dong, Songpa-ku, Seoul 138-736, Korea. kimkw@amc.seoul.kr
authors.forename: Kyoung Won
authors.initials: KW
authors.lastname: Kim
authors.forename: Min-Jeong
authors.initials: MJ
authors.lastname: Kim
authors.forename: Hyo-Cheol
authors.initials: HC
authors.lastname: Kim
authors.forename: Seong Ho
authors.initials: SH
authors.lastname: Park
authors.forename: So Yeon
authors.initials: SY
authors.lastname: Kim
authors.forename: Mi-Suk
authors.initials: MS
authors.lastname: Park
authors.forename: Tae Kyoung
authors.initials: TK
authors.lastname: Kim
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001707:Biopsy, Needle / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging* / Q000293:injuries / Q000473:pathology*; D008107:Liver Diseases / Q000000981:diagnostic imaging* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D019106:Postoperative Hemorrhage / Q000000981:diagnostic imaging* / Q000209:etiology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018608:Ultrasonography, Doppler / Q000379:methods*