title: Diagnosis of small posterior fossa stroke on brain CT: effect of iterative reconstruction designed for brain CT on detection performance.
abstract: OBJECTIVE
  In this study, we aimed to determine whether iterative model reconstruction designed for brain CT (IMR-neuro) would improve the accuracy of posterior fossa stroke diagnosis on brain CT.
  
  
  METHODS
  We enrolled 37 patients with ischaemic stroke in the posterior fossa and 37 patients without stroke (controls). Using axial images reconstructed using filtered back-projection (FBP) and IMR-neuro, we compared the CT numbers in infarcted areas, image noise in the pons, and contrast-to-noise ratios (CNRs) of infarcted and non-infarcted areas on scans subjected to IMR-neuro and FBP. To analyse the performance of hypo-attenuation detection, we used receiver-operating characteristic (ROC) curve techniques.
  
  
  RESULTS
  The image noise was significantly lower (2.2 ± 0.5 vs. 5.1 ± 0.9 Hounsfield units, p < 0.01) and the difference in CNR between the infarcted and non-infarcted areas was significantly higher with IMR-neuro than with FBP (2.2 ± 1.7 vs. 4.0 ± 3.6, p < 0.01). Furthermore, the average area under the ROC curve was significantly higher with IMR-neuro (0.90 vs. 0.86 for FBP, p = 0.04).
  
  
  CONCLUSIONS
  IMR-neuro yielded better image quality and improved hypo-attenuation detection in patients with ischaemic stroke.
  
  
  CONCLUSIONS
  • Iterative model reconstruction of brain CT data can facilitate the diagnosis of ischaemic stroke. • IMR improved the detectability of low-contrast lesions in the posterior fossa. • IMR-neuro yielded better image quality and improved observer performance.
authors.affiliation: Department of Radiology, Amakusa Medical Center, 854-1 Jikiba, Amakusa, Kumamoto, Japan. srdct119@icloud.com.
authors.forename: Taihei
authors.initials: T
authors.lastname: Inoue
authors.affiliation: Department of Diagnostic Radiology, Graduate School of Life Sciences, Kumamoto University, Kumamoto, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nakaura
authors.affiliation: Department of Radiology, Amakusa Medical Center, 854-1 Jikiba, Amakusa, Kumamoto, Japan.
authors.forename: Morikatsu
authors.initials: M
authors.lastname: Yoshida
authors.affiliation: Department of Radiology, Amakusa Medical Center, 854-1 Jikiba, Amakusa, Kumamoto, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Yokoyama
authors.affiliation: Department of Diagnostic Radiology, Graduate School of Life Sciences, Kumamoto University, Kumamoto, Japan.
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Hirata
authors.affiliation: Department of Diagnostic Radiology, Graduate School of Life Sciences, Kumamoto University, Kumamoto, Japan.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Kidoh
authors.affiliation: Department of Diagnostic Radiology, Graduate School of Life Sciences, Kumamoto University, Kumamoto, Japan.
authors.forename: Seitaro
authors.initials: S
authors.lastname: Oda
authors.affiliation: Department of Diagnostic Radiology, Graduate School of Life Sciences, Kumamoto University, Kumamoto, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Utsunomiya
authors.affiliation: Department of Surgery, Amakusa Medical Center, Kumamoto, Japan.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Harada
authors.affiliation: Department of Diagnostic Radiology, Graduate School of Life Sciences, Kumamoto University, Kumamoto, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Yamashita
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D002545:Brain Ischemia / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D059906:Neuroimaging / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods; D012189:Retrospective Studies; D020521:Stroke / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: Computed tomography; Image processing; Posterior fossa; Radiation dosage; Stroke