Lack of evidence for pulmonary venous thrombosis in cryptogenic stroke: a magnetic resonance angiography study.
BACKGROUND
Even after extensive evaluation, the etiology of ischemic stroke remains undefined in a considerable proportion of cases, suggesting that causes of stroke may exist that have not yet been established. We tested the hypothesis that pulmonary venous thrombosis (PVT) is a potential source of brain embolism in patients with cryptogenic stroke.


METHODS
Within 7 days after mild to moderately severe ischemic stroke or transient ischemic attack, 18 patients (9 women, 9 men; mean age, 48 years) were studied in whom the etiology remained undefined despite complete workup. All patients received high-resolution pulmonary venography with the use of multiple-bolus, multiphase, 3-dimensional, gadolinium-enhanced MR angiography (MRA). Overall quality of the MRA was good in 14 and insufficient in 4 patients, mainly as a result of breathing artifacts. Visualization of the main and segmental veins and evaluability of their patency were good for most right pulmonary veins but often inadequate for left pulmonary veins, particularly for those in the left lower lobe. There was no evidence for PVT in any of the sufficiently visualized pulmonary veins.


CONCLUSIONS
The results do not support the hypothesis of PVT as a contributor to the etiology of ischemic stroke. However, the study was limited regarding scan volume, spatial discrimination, patient selection, and delay between ischemia and MRA. Therefore, further investigations, including postmortem studies, are needed to resolve the question of whether PVT may contribute to ischemic stroke.
Grau
Armin J
AJ
Department of Neurology, University of Heidelberg, Heidelberg, Germany. armin_grau@med.uni-heidelberg.de
Schoenberg
Stefan O
SO
Lichy
Christoph
C
Buggle
Florian
F
Bock
Michael
M
Hacke
Werner
W
D000328:Adult; D016477:Artifacts; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D010690:Phlebography; D011667:Pulmonary Veins / Q000033:anatomy & histology; D011668:Pulmonary Veno-Occlusive Disease / Q000150:complications*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D020521:Stroke / Q000175:diagnosis* / Q000209:etiology*; D014654:Vascular Patency / Q000502:physiology; D020246:Venous Thrombosis / Q000150:complications*
D003287:Contrast Media; D019786:Gadolinium DTPA