title: Feasibility of time-resolved MR angiography for detecting recanalization of pulmonary arteriovenous malformations treated with embolization with platinum coils.
abstract: OBJECTIVE
  To assess the feasibility of time-resolved magnetic resonance (MR) angiography as a follow-up method after embolization for pulmonary arteriovenous malformations (PAVMs).
  
  
  METHODS
  Evaluation of 28 PAVMs in 10 patients previously treated with embolization with platinum coils was performed. The mean observation period after embolization was 49 months. All patients underwent unenhanced chest computed tomography (CT) and time-resolved MR angiography followed by transcatheter digital subtraction angiography within 5 weeks for a definite diagnosis. Two radiologists reviewed the CT and time-resolved MR angiography findings using a blinded method. On CT, the draining veins of the PAVMs were measured before and after embolization, and shrinkage rates were calculated. On time-resolved MR angiography, recanalization was diagnosed when the draining vein or aneurysmal sac or both were enhanced in the pulmonary arterial phase. Correlations between recanalization, the shrinkage rate of the draining vein, and the diagnostic accuracies of CT and time-resolved MR angiography were assessed and compared with digital subtraction angiography.
  
  
  RESULTS
  Five lesions could not be measured on CT because of metallic artifacts. The mean shrinkage rates of the draining vein for recanalized and occluded PAVMs were 23% ± 19 (SD) for recanalized PAVMs and 47% ± 21 for occluded PAVMs (P = .001). The sensitivity and specificity were 93% and 53%, respectively, when the shrinkage rate threshold was set to 50%. On time-resolved MR angiography, the sensitivity and specificity were 93% and 100%, respectively, for Reader 1 and 100% and 93%, respectively, for Reader 2. The κ coefficient was 0.86.
  
  
  CONCLUSIONS
  Time-resolved MR angiography appears to be a feasible method for PAVM follow-up examinations and to provide a more accurate diagnosis of recanalization compared with unenhanced CT.
authors.affiliation: Department of Radiology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, 467-8601 Japan. Electronic address: tatsuyak@med.nagoya-cu.ac.jp.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Kawai
authors.affiliation: Department of Radiology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, 467-8601 Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Shimohira
authors.affiliation: Division of Central Radiology, Nagoya City University Hospital, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, 467-8601 Japan.
authors.forename: Hirohito
authors.initials: H
authors.lastname: Kan
authors.affiliation: Department of Radiology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, 467-8601 Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Hashizume
authors.affiliation: Department of Radiology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, 467-8601 Japan.
authors.forename: Kengo
authors.initials: K
authors.lastname: Ohta
authors.affiliation: Department of Radiology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, 467-8601 Japan.
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Kurosaka
authors.affiliation: Department of Radiology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, 467-8601 Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Muto
authors.affiliation: Department of Radiology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, 467-8601 Japan.
authors.forename: Kazushi
authors.initials: K
authors.lastname: Suzuki
authors.affiliation: Department of Radiology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, 467-8601 Japan.
authors.forename: Yuta
authors.initials: Y
authors.lastname: Shibamoto
mesh_terms: D000328:Adult; D000368:Aged; D015901:Angiography, Digital Subtraction; D001165:Arteriovenous Malformations / Q000175:diagnosis* / Q000628:therapy*; D016477:Artifacts; D004621:Embolization, Therapeutic / Q000009:adverse effects / Q000295:instrumentation*; D004867:Equipment Design; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010984:Platinum; D011237:Predictive Value of Tests; D011651:Pulmonary Artery / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000473:pathology; D011667:Pulmonary Veins / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000473:pathology; D015203:Reproducibility of Results; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D010984:Platinum