Diagnostic Value of Perfusion-Weighted Magnetic Resonance Imaging as an Adjunct to Routine Magnetic Resonance Protocols for Adults Presenting with Acute Ischemic Stroke

Figures & data

Table 1 Search summary

	Population	Intervention	Outcome
Generic Terms	Adults with ischemic stroke	Perfusion-weighted MRI	Diagnostic accuracy
Applied search terms (columns combined with “AND”) (*truncation)	1. Adult 2. Ischemic stroke 3. Ischemic stroke 4. Stroke	5. Perfusion-weighted magnetic resonance imaging 6. Perfusion-weighted imaging 7. PW MRI	11. Diagnosis 12. Diagnostic accuracy 13. Detection 14. Characterization 15. Evaluation 16. Sensitivity 17. Specificity 18. Predictive value
Boolean combinations	1 AND 2 OR 3 OR 4	5 OR 6 OR 7 OR 8 OR 9 OR 10 OR 11	11 OR 12 OR 13 OR 14 OR 15 OR 16 OR 17 OR 18

Table 2 Inclusion and exclusion criteria

Inclusion criteria	• Articles written in English; • Research published between 2005–2020; • Primary studies of diagnostic accuracy design; • Adults aged ≥18 years with ischemic stroke; • Quantitative studies comparing the diagnostic accuracy of Perfusion-weighted MRI with other MRI protocols; • Outcome measures of diagnostic utility and accuracy and reports of image interpreters.
Exclusion criteria	• Non-English language publications; • Any research undertaken before 2005; • Systematic or other reviews; • Children aged <18 years or adults with diagnoses other than ischemic stroke.

Figure 1 PRISMA flowchart.

Notes: PRISMA figure adapted from Moher D, Liberati A, Tetzlaff J, et al. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. PLoS Med. 2009;6(7):e1000097. Creative Commons.²⁸

Table 3 Calculation of sensitivity and specificity²⁶

	Disease Present	Disease Absent
Test positive	a (TP)	b (FP)
Test negative	c (FN)	d (TN)
	Sensitivity:	Specificity:
	a/(a+c)	d/(b+d)

Table 4 Summary of study characteristics

	Sample size	Participants	Index MRI	Comparator MRI
Kucinski et al^Citation29 (US)	n=19	Patients with symptoms of acute ischemic stroke within the carotid-artery area presenting within 6 hours of symptom onset	Perfusion-weighted Gradient echo-planar Slice thickness 6–7 mm	Diffusion-weighted (echo-planar)
Butcher et al^Citation30 (Australia)	n=35	Adults with symptoms of stroke and presenting within 6 hours of onset	Perfusion-weighted Slice thickness 5–6 mm	Diffusion-weighted (echo-planar) Slice thickness 5–6 mm
Cho et al^Citation31 (Denmark)	n=109	Patients receiving MRI and tissue plasminogen- activator therapy within 6 hours of ischemic stroke onset	Perfusion-weighted Echo-planar	Diffusion-weighted (echo-planar) and MR angiography
Copen et al^Citation32 (US)	n=77	Patients receiving MRI for stroke with evidence of anterior circulation infarction	Perfusion-weighted Echo-planar	Diffusion-weighted (echo-planar)
Straka et al^Citation33 (US)	n=63	Patients with acute stroke and receiving rapid processing of perfusion and diffusion (RAPID) assessments via MRI	Perfusion-weighted (DSC), but technical details not reported	Diffusion-weighted, but technical details not reported
Luby et al^Citation34 (US)	n=70	Patients with stroke symptoms receiving tissue plasminogen-activator therapy within 3 hours of symptom onset	Perfusion-weighted Gradient echo-planar Slice thickness 7 mm	Diffusion-weighted (echo-planar) Slice thickness 7 mm
Motta et al^Citation35 (US)	n=38	Patients with a clinical diagnosis of anterior circulation stroke and imaging within 24 hours of symptom onset	Perfusion-weighted, but technical details not reported	Diffusion-weighted, but technical details not reported
Simonsen et al^Citation36 (US)	n=559	Patients with symptoms of acute stroke and received MRI imaging	Perfusion-weighted (DSC), but technical details not reported	Diffusion-weighted and fluid- attenuated inversion recovery, but technical details not reported
Wolman et al^Citation37 (US)	n=146	Patients who underwent MRI for assessment of acute cerebral ischemia	Perfusion-weighted Echo-planar	Diffusion-weighted (echo-planar) and MR angiography
Hakimelahi et al^Citation38 (US)	n=68	Patients taken from the data set of Copen et al (2009)	Perfusion-weighted Gradient echo-planar Slice thickness 5 mm	Diffusion-weighted (echo-planar) Slice thickness 5 mm
Total	n=1,184

Table 5 Summary of risk of bias using QUADAS-2

Study	Quality of evidence	Patient selection	Index tests	Reference standard	Patient flow and timing
Butcher et al^Citation30	Risk of bias	High	High	High	High
	Applicability	Low	Low	High	—
Cho et al^Citation31	Risk of bias	High	High	High	High
	Applicability	Low	Low	High	—
Copen et al^Citation32	Risk of bias	Low	High	High	High
	Applicability	Low	Low	High	—
Hakimelahi et al^Citation38	Risk of bias	Low	Unclear	High	High
	Applicability	Low	Low	High	—
Kucinski et al^Citation29	Risk of bias	High	High	High	High
	Applicability	Low	Low	High	—
Luby et al^Citation34	Risk of bias	High	Unclear	High	High
	Applicability	Low	Low	High	—
Motta et al^Citation35	Risk of bias	High	High	High	High
	Applicability	Low	Low	High	—
Simonsen et al^Citation36	Risk of bias	Low	Unclear	High	High
	Applicability	Low	Low	High	—
Straka et al^Citation33	Risk of bias	Unclear	High	High	High
	Applicability	Low	Low	High	—

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