Comparison of 4 cm Z-axis and 16 cm Z-axis multidetector CT perfusion

Abstract

The increased field of view with MD320 better defines the true extent of the infarct core and ischaemic penumbra. It also identified other areas of infarction that were not identified on the 4 cm Z-axis.

Whole-Brain Perfusion CT Using a Toggling Table Technique to Predict Final Infarct Volume in Acute Ischemic Stroke

“…However, the cerebral volume principle used in our study to calculate the dynamic perfusion parameters which is based on the mathematic principle of deconvolution yields quantitative CBV, CBF, and MTT values at low injection speeds and thus independently of a delay of the contrast agent passage [15,32] in contrast to the so-called maximum slope model, which is based on the assumption that no contrast agent exits the compartment via a venous path up to a certain point in time after arrival of the bolus in the tissue [33]. The average effective dose of our PCT protocol was 8.4 mSv and therefore differs only minimally from the dose of 7.6 mSv applied for PCT with a 320-slice MDCT unit [23]. As a result of the relatively high total dose of 4.7 -9.5 mSv for an imaging protocol typically consisting of numerous CT examinations on a 64-slice MDCT unit [23,34], possibly followed by catheter angiography, the indication for the individual examination and the selection of the follow-up examination method must be reviewed in each case.…”

“…The average effective dose of our PCT protocol was 8.4 mSv and therefore differs only minimally from the dose of 7.6 mSv applied for PCT with a 320-slice MDCT unit [23]. As a result of the relatively high total dose of 4.7 -9.5 mSv for an imaging protocol typically consisting of numerous CT examinations on a 64-slice MDCT unit [23,34], possibly followed by catheter angiography, the indication for the individual examination and the selection of the follow-up examination method must be reviewed in each case. The benefit of the examination with respect to the survival and the least possible subsequent impairment of the stroke patient must be taken into consideration here.…”

“…The attempt to resolve this issue by increasing the examination area by scanning different sections of the brain in succession resulted in increased radiation exposure for the patient and the use of a greater contrast agent quantity due to the repeated applications [3, 24,25]. PCT using a 256-slice or 320-slice MCDT unit recently made it possible to record hemodynamic data for the entire brain after only one contrast agent application and with a relatively low radiation dose [12,23]. However, most hospitals use MDCT units with significantly The patients with and without successful recanalization are listed according to gender and age, and according to the selected imaging methods.…”

“…Compared to examination via MRI perfusion, the main disadvantage of PCT using 4 and 16-slice MDCT units is the small scanning area due to the narrow detector width so that complete scanning of hypoperfused areas and infarcts in cranial sections of the cerebrum is not reliably ensured [11,22,23]. The attempt to resolve this issue by increasing the examination area by scanning different sections of the brain in succession resulted in increased radiation exposure for the patient and the use of a greater contrast agent quantity due to the repeated applications [3, 24,25].…”

Angiographic Reconstructions From Whole-Brain Perfusion CT for the Detection of Large Vessel Occlusion in Acute Stroke

“…It has been shown that increasing the z-axis coverage of perfusion CT scans can improve the diagnostic sensitivity for detecting ischemic lesions. 13,15 However, diagnostic evaluation of VPCT examinations typically focuses on functional abnormalities detected on the perfusion parameter maps such as cerebral blood volume, cerebral blood flow, mean transit time, and time to peak, whereas vascular reconstructions are not routinely obtained.…”