Interleaving cerebral CT perfusion with neck CT angiography part I. Proof of concept and accuracy of cerebral perfusion values

Eur Radiol. 2017 Jun;27(6):2649-2656. doi: 10.1007/s00330-016-4577-y. Epub 2016 Oct 7.


Objectives: We present a novel One-Step-Stroke protocol for wide-detector CT scanners that interleaves cerebral CTP with volumetric neck CTA (vCTA). We evaluate whether the resulting time gap in CTP affects the accuracy of CTP values.

Methods: Cerebral CTP maps were retrospectively obtained from 20 patients with suspicion of acute ischemic stroke and served as the reference standard. To simulate a 4 s gap for interleaving CTP with vCTA, we eliminated one acquisition at various time points of CTP starting from the bolus-arrival-time(BAT). Optimal timing of the vCTA was evaluated. At the time point with least errors, we evaluated elimination of a second time point (6 s gap).

Results: Mean absolute percentage errors of all perfusion values remained below 10 % in all patients when eliminating any one time point in the CTP sequence starting from the BAT. Acquiring the vCTA 2 s after reaching a threshold of 70HU resulted in the lowest errors (mean <3.0 %). Eliminating a second time point still resulted in mean errors <3.5 %. CBF/CBV showed no significant differences in perfusion values except MTT. However, the percentage errors were always below 10 % compared to the original protocol.

Conclusion: Interleaving cerebral CTP with neck CTA is feasible with minor effects on the perfusion values.

Key points: • Removing a single CTP acquisition has minor effects on calculated perfusion values • Calculated perfusion values errors depend on timing of skipping a CTP acquisition • Qualitative evaluation of CTP was not influenced by removing two time points • Neck CTA is optimally timed in the upslope of arterial enhancement.

Keywords: Angiography; Brain; Multidetector computed tomography; Perfusion; Stroke.

Publication types

  • Evaluation Study

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Brain Ischemia / diagnostic imaging
  • Brain Ischemia / physiopathology
  • Cerebral Angiography / methods
  • Cerebrovascular Circulation / physiology*
  • Computed Tomography Angiography / methods
  • Female
  • Humans
  • Male
  • Middle Aged
  • Multidetector Computed Tomography / methods
  • Multimodal Imaging
  • Neck
  • Retrospective Studies
  • Stroke / diagnostic imaging*
  • Stroke / physiopathology