Single-Phase Versus Multiphase CT Angiography in Middle Cerebral Artery Clot Detection-Benefits for Less Experienced Radiologists and Neurologists.
OBJECTIVE
CT angiography (CTA) is recommended as a standard of stroke imaging. We investigated accuracy and precision of standard or single-phase CTA as compared with novel technique or multiphase CTA in clot detection in the middle cerebral artery.


METHODS
Twenty single-phase CTA and twenty multiphase CTA with prevailing M2 occlusion were assessed by 10 radiologists and 10 neurologists blinded to clinical information (7 less experienced and 3 experienced). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated as compared with reading by two seniors. Reliability was calculated using Krippendorff's alpha (K-alpha).


RESULTS
Sensitivity, specificity, PPV, and NPV of single-phase CTA compared with multiphase CTA for M2 clot presence were, respectively, .86, .75, .90, and .67 versus .88, .82, .92, and .72. For secondary or distal clots, sensitivity, specificity, PPV, and NPV of single-phase CTA compared with multiphase CTA were .41, .83, .50, and .78 versus .65, .77, .71, and .67. Agreement increased significantly in favor of multiphase CTA for detection of primary clots from moderate (.43) to substantial (.65) in less experienced radiologists and from slight (.10) to moderate (.30) in less experienced neurologists. Agreement significantly increased for distal or secondary clot detection in favor of multiphase CTA from fair (.24) to moderate (.49) in experienced radiologists and from slight (.12) to moderate (.46) in experienced neurologists.


CONCLUSIONS
Multiphase CTA is a reliable imaging tool in M2 clot detection and might represent a beneficial imaging tool in clot detection for less experienced physicians.
Stroke Research Program, International Clinical Research Center, St. Anne's University Hospital, Brno, Czech Republic; Department of Neurology, Faculty of Medicine, St. Anne's University Hospital, Masaryk University, Brno, Czech Republic. Electronic address: 214565@mail.muni.cz.
Ondrej
O
Volny
Stroke Research Program, International Clinical Research Center, St. Anne's University Hospital, Brno, Czech Republic; Department of Medical Imaging, Faculty of Medicine, St. Anne's University Hospital, Masaryk University, Brno, Czech Republic.
Petra
P
Cimflova
Stroke Research Program, International Clinical Research Center, St. Anne's University Hospital, Brno, Czech Republic.
Pavla
P
Kadlecova
Faculty of Medicine, Masaryk University, Brno, Czech Republic.
Petr
P
Vanek
Department of Medical Imaging, Faculty of Medicine, St. Anne's University Hospital, Masaryk University, Brno, Czech Republic.
Jiri
J
Vanicek
Calgary Stroke Program, Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.
Bijoy K
BK
Menon
Stroke Research Program, International Clinical Research Center, St. Anne's University Hospital, Brno, Czech Republic; Department of Neurology, Faculty of Medicine, St. Anne's University Hospital, Masaryk University, Brno, Czech Republic.
Robert
R
Mikulik
D015331:Cohort Studies; D000072226:Computed Tomography Angiography / Q000379:methods*; D005260:Female; D006801:Humans; D020767:Intracranial Thrombosis / Q000000981:diagnostic imaging* / Q000209:etiology; D008297:Male; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging*; D000072141:Neurologists / Q000523:psychology*; D000072177:Radiologists / Q000523:psychology*; D012680:Sensitivity and Specificity; D020521:Stroke / Q000150:complications; D013997:Time Factors
CT angiography; acute stroke; distal clot; middle cerebral artery; multiphase CTA