HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Provenzale, J. M. Search for Related Content PubMed PubMed Citation Articles by Provenzale, J. M. Related Collections Neuroradiology Emergency Radiology

Nontraumatic Neurologic Emergencies: Imaging Findings and Diagnostic Pitfalls¹

¹ From the Department of Radiology, Duke University Medical Center, Erwin Rd, Durham, NC 27710. From the Plenary Session, Friday Imaging Symposium: Acute Radiology—Where Minutes Count, at the 1998 RSNA scientific assembly. Received March 15, 1999; revision requested May 4 and received June 2; accepted June 8. Address reprint requests to the author.

View larger version (136K): [in a new window]   Figure 1a.   Early infarct in the territory of the left middle cerebral artery in a 52-year-old man. (a) Unenhanced axial CT image shows increased attenuation of the left middle cerebral artery (arrow) due to a thrombus. (b) CT image obtained a few images cephalad to a shows subtle decreased attenuation within the left insula (arrows) relative to that in the right hemisphere (arrowhead).

View larger version (146K): [in a new window]   Figure 1b.   Early infarct in the territory of the left middle cerebral artery in a 52-year-old man. (a) Unenhanced axial CT image shows increased attenuation of the left middle cerebral artery (arrow) due to a thrombus. (b) CT image obtained a few images cephalad to a shows subtle decreased attenuation within the left insula (arrows) relative to that in the right hemisphere (arrowhead).

View larger version (164K): [in a new window]   Figure 2.   Early infarction in a 2-year-old girl with sudden onset of left hemiparesis a few days after cardiac surgery. Unenhanced axial CT image shows that the right basal ganglia (open arrows) are slightly hypoattenuating relative to the left basal ganglia (solid arrow). Note that the left basal ganglia are distinctly seen against the background of the left internal capsule (arrowhead), but the distinction between these two structures is blurred in the right hemisphere because of the lower attenuation of the right basal ganglia.

View larger version (151K): [in a new window]   Figure 3a.   Hyperacute stroke in a 50-year-old man with bacterial endocarditis and suspected cerebral infarction. (a) Axial proton density-weighted MR image shows subtle regions of high signal intensity at the gray-white matter junction (arrows). (b) Corresponding diffusion-weighted MR image shows the infarcts more clearly (arrows). The pattern of infarcts in multiple vascular distributions is consistent with embolic infarction.

View larger version (112K): [in a new window]   Figure 3b.   Hyperacute stroke in a 50-year-old man with bacterial endocarditis and suspected cerebral infarction. (a) Axial proton density-weighted MR image shows subtle regions of high signal intensity at the gray-white matter junction (arrows). (b) Corresponding diffusion-weighted MR image shows the infarcts more clearly (arrows). The pattern of infarcts in multiple vascular distributions is consistent with embolic infarction.

View larger version (162K): [in a new window]   Figure 4a.   Infarcts of different ages in a 60-year-old man with new onset of right hemiparesis. (a) Axial proton density-weighted MR image shows multiple regions of high signal intensity in both cerebral hemispheres (arrows). The lesions are isointense relative to one another, and their relative ages cannot be discerned. (b) Corresponding diffusion-weighted MR image shows that some of the lesions are hyperintense (open arrows), an appearance consistent with acute infarcts. In particular, one lesion that is relatively subtle on the proton density-weighted image (a) is much more conspicuous (solid arrow). The remainder of the lesions seen on the proton density-weighted image (a) are isointense relative to normal brain tissue on the diffusion-weighted image (b); this finding indicates that these lesions are subacute or chronic.

View larger version (118K): [in a new window]   Figure 4b.   Infarcts of different ages in a 60-year-old man with new onset of right hemiparesis. (a) Axial proton density-weighted MR image shows multiple regions of high signal intensity in both cerebral hemispheres (arrows). The lesions are isointense relative to one another, and their relative ages cannot be discerned. (b) Corresponding diffusion-weighted MR image shows that some of the lesions are hyperintense (open arrows), an appearance consistent with acute infarcts. In particular, one lesion that is relatively subtle on the proton density-weighted image (a) is much more conspicuous (solid arrow). The remainder of the lesions seen on the proton density-weighted image (a) are isointense relative to normal brain tissue on the diffusion-weighted image (b); this finding indicates that these lesions are subacute or chronic.

View larger version (157K): [in a new window]   Figure 5a.   Hemorrhagic venous infarction in a 68-year-old man with a 1-week history of severe headaches. (a) Unenhanced coronal T1-weighted MR image shows a hyperintense focus consistent with hemorrhage in the right temporal lobe (straight arrow). The subcortical location and the hemorrhagic nature of the lesion are typical of a venous infarct. The flow voids of the right sigmoid sinus (curved arrow) and superior sagittal sinus (arrowhead) are replaced by abnormal high signal intensity, which is consistent with thrombosis. (b) Axial T2-weighted MR image shows a hemorrhagic infarct in the left parietal lobe (straight arrows) and high signal intensity in the superior sagittal sinus (curved arrow), findings consistent with thrombosis.

View larger version (152K): [in a new window]   Figure 5b.   Hemorrhagic venous infarction in a 68-year-old man with a 1-week history of severe headaches. (a) Unenhanced coronal T1-weighted MR image shows a hyperintense focus consistent with hemorrhage in the right temporal lobe (straight arrow). The subcortical location and the hemorrhagic nature of the lesion are typical of a venous infarct. The flow voids of the right sigmoid sinus (curved arrow) and superior sagittal sinus (arrowhead) are replaced by abnormal high signal intensity, which is consistent with thrombosis. (b) Axial T2-weighted MR image shows a hemorrhagic infarct in the left parietal lobe (straight arrows) and high signal intensity in the superior sagittal sinus (curved arrow), findings consistent with thrombosis.

View larger version (141K): [in a new window]   Figure 6a.   Dural sinus thrombosis in a 20-year-old woman with a 2-week history of worsening headache. (a) Unenhanced axial CT image shows increased attenuation in the superior sagittal sinus (straight arrow) and straight sinus (curved arrow), findings consistent with thrombosis. (b) Unenhanced sagittal MR image shows replacement of the flow void of the superior sagittal sinus by intermediate signal intensity (arrows), which indicates thrombosis. (c) Contrast-enhanced axial MR image shows absence of the flow void in the superior sagittal sinus (straight arrow) and straight sinus (curved arrow) with mild enhancement of the periphery of the thrombus. (Courtesy of D. James Schumacher, MD, Cape Canaveral Hospital, Melbourne, Fla.)

View larger version (140K): [in a new window]   Figure 6b.   Dural sinus thrombosis in a 20-year-old woman with a 2-week history of worsening headache. (a) Unenhanced axial CT image shows increased attenuation in the superior sagittal sinus (straight arrow) and straight sinus (curved arrow), findings consistent with thrombosis. (b) Unenhanced sagittal MR image shows replacement of the flow void of the superior sagittal sinus by intermediate signal intensity (arrows), which indicates thrombosis. (c) Contrast-enhanced axial MR image shows absence of the flow void in the superior sagittal sinus (straight arrow) and straight sinus (curved arrow) with mild enhancement of the periphery of the thrombus. (Courtesy of D. James Schumacher, MD, Cape Canaveral Hospital, Melbourne, Fla.)

View larger version (138K): [in a new window]   Figure 6c.   Dural sinus thrombosis in a 20-year-old woman with a 2-week history of worsening headache. (a) Unenhanced axial CT image shows increased attenuation in the superior sagittal sinus (straight arrow) and straight sinus (curved arrow), findings consistent with thrombosis. (b) Unenhanced sagittal MR image shows replacement of the flow void of the superior sagittal sinus by intermediate signal intensity (arrows), which indicates thrombosis. (c) Contrast-enhanced axial MR image shows absence of the flow void in the superior sagittal sinus (straight arrow) and straight sinus (curved arrow) with mild enhancement of the periphery of the thrombus. (Courtesy of D. James Schumacher, MD, Cape Canaveral Hospital, Melbourne, Fla.)

View larger version (130K): [in a new window]   Figure 7a.   Carotid artery dissection in a 44-year-old man with onset of neck pain while skiing. (a) Unenhanced axial T1-weighted MR image shows a rim of high signal intensity around the flow void of the right internal carotid artery (arrowhead). (b) Lateral angiogram of the right internal carotid artery shows a long segment of narrowing (arrows) beginning a few centimeters beyond the carotid bifurcation, a typical site for dissection of the extracranial segment of this artery.

View larger version (111K): [in a new window]   Figure 7b.   Carotid artery dissection in a 44-year-old man with onset of neck pain while skiing. (a) Unenhanced axial T1-weighted MR image shows a rim of high signal intensity around the flow void of the right internal carotid artery (arrowhead). (b) Lateral angiogram of the right internal carotid artery shows a long segment of narrowing (arrows) beginning a few centimeters beyond the carotid bifurcation, a typical site for dissection of the extracranial segment of this artery.

View larger version (114K): [in a new window]   Figure 8.   Pseudoaneurysm due to carotid artery dissection in a 55-year-old woman with right-sided pulsatile tinnitus. Lateral angiogram of the right internal carotid artery shows a pseudoaneurysm (arrow) due to arterial dissection at the junction of the cervical and petrous segments of the artery.