| Vol. 4, Issue 2, Article 2 |
|
Sanelli, P., Shetty, S. & Lev, M. |
| Table 2. CTA/CTP vs. MRA/MRP (Fig. 8) | ||
| CT | MR | |
| Advantages | *Fast, available, less expensive *Better in emergency setting and for critically ill patients |
*No radiation |
| Disadvantages | *Limited CTP coverage (2 cm per cine bolus acquisition) | *Non-linear relationship between contrast concentration and signal intensity |
| Resolution | *Improved spatial resolution |
*Improved contrast resolution |
| Artifacts | *Beam hardening (metal, bone) |
*Flow-related “slow flow” |
| Patient contraindications | *Allergy to iodinated contrast |
*Implantable devices (pacemakers, cochlear implants, clips of uncertain origin, claustrophobia) |
| Angiography data |
*Anatomic data – non-flow dependent |
*Physiologic data - flow-dependent |
| Perfusion agents | *Iodinated contrast |
*Gadolinium contrast |
Perfusion data |
*Qualitative or quantitative | *Qualitative only (relative values) |
| Total acquisition time for Angio/Perfusion exam | *10 – 15 min |
*30 – 45 min |
| Detection of: | ||
| 1. Vascular occlusion | *CTA > MRA |
*MRA < CTA |
| 2. “Core” infarct | *CBV, CTA-SI, NCCT |
*DWI > CT-CBV |
| 3. “Ischemic penumbra” | *CT-CBV/CT-CBF, MTT mismatch |
*DWI/MR-CBF,MTT mismatch |
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