title: Wavelet-Based Angiographic Reconstruction of Computed Tomography Perfusion Data: Diagnostic Value in Cerebral Venous Sinus Thrombosis.
abstract: The aim of this study was to test the diagnostic value of wavelet-based angiographic reconstruction of CT perfusion data (waveletCTA) to detect cerebral venous sinus thrombosis (CVST) in patients who underwent whole-brain CT perfusion imaging (WB-CTP).
  
  
  
  Datasets were retrospectively selected from an initial cohort of 2863 consecutive patients who had undergone multiparametric CT including WB-CTP. WaveletCTA was reconstructed from WB-CTP: the angiographic signal was generated by voxel-based wavelet transform of time attenuation curves (TACs) from WB-CTP raw data. In a preliminary clinical evaluation, waveletCTA was analyzed by 2 readers with respect to presence and location of CVST. Venous CT and MR angiography (venCTA/venMRA) served as reference standard. Diagnostic confidence for CVST detection and the quality of depiction for venous sections were evaluated on 5-point Likert scales. Thrombus extent was assessed by length measurements. The mean CT attenuation and waveletCTA signal of the thrombus and of flowing blood were quantified.
  
  
  
  Sixteen patients were included: 10 patients with venCTA-/venMRA-confirmed CVST and 6 patients with arterial single-phase CT angiography (artCTA)-suspected but follow-up-excluded CVST. The reconstruction of waveletCTA was successful in all patients. Among the patients with confirmed CVST, waveletCTA correctly demonstrated presence, location, and extent of the thrombosis in 10/10 cases. In 6 patients with artCTA-suspected but follow-up-excluded CVST, waveletCTA correctly ruled out CVST in 5 patients. Reading waveletCTA in addition to artCTA significantly increased the diagnostic confidence concerning CVST compared with reading artCTA alone (4.4 vs 3.6, P = 0.044). The mean flowing blood-to-thrombus ratio was highest in waveletCTA, followed by venCTA and artCTA (146.2 vs 5.9 vs 2.6, each with P < 0.001). In waveletCTA, the venous sections were depicted better compared with artCTA (4.2 vs 2.6, P < 0.001), and equally well compared with venCTA/venMRA (4.2 vs 4.1, P = 0.374).
  
  
  
  WaveletCTA was technically feasible in CVST patients and reliably identified CVST in a preliminary clinical evaluation. WaveletCTA might serve as an additional reconstruction to rule out or incidentally detect CVST in patients who undergo WB-CTP.
authors.affiliation: From the *Institute for Clinical Radiology, and †Josef Lissner Laboratory for Biomedical Imaging of the Institute for Clinical Radiology, Ludwig-Maximilian-University Hospital Munich, Germany.
authors.forename: Wolfgang G
authors.initials: WG
authors.lastname: Kunz
authors.forename: Felix
authors.initials: F
authors.lastname: Schuler
authors.forename: Wieland H
authors.initials: WH
authors.lastname: Sommer
authors.forename: Matthias P
authors.initials: MP
authors.lastname: Fabritius
authors.forename: Lukas
authors.initials: L
authors.lastname: Havla
authors.forename: Felix G
authors.initials: FG
authors.lastname: Meinel
authors.forename: Maximilian F
authors.initials: MF
authors.lastname: Reiser
authors.forename: Birgit
authors.initials: B
authors.lastname: Ertl-Wagner
authors.forename: Kolja M
authors.initials: KM
authors.lastname: Thierfelder
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002533:Cerebral Angiography / Q000379:methods*; D000072226:Computed Tomography Angiography / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D055420:Perfusion Imaging / Q000379:methods; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012851:Sinus Thrombosis, Intracranial / Q000000981:diagnostic imaging*