Acute infarction of the caudate head and lentiform nucleus

Both structures are supplied by the lateral lenticulostriate arteries, which originate from the MCA. The caudate nucleus is also supplied by the medial lenticulostriate arteries, which arise from the ACA. The recurrent artery of Heubner, which supplies the anteromedial caudate nucleus and the anteroinferior internal capsule, is the largest of the medial lenticulostriate arteries, and […] [...]

Acute lacunar infarction, posterior limb of the internal capsule

The patient was hypertensive, and presented for CT (which was negative) with acute hypoesthesia involving the left side of the body. The MR was obtained 15 hours later, and reveals a small acute lacunar infarct in the internal capsule on the right. Due to the ability to detect cytotoxic edema, with diffusion weighted imaging, MR […] [...]

Acute medial medullary infarct

Abnormal hyperintensity is noted in the right medial medulla on both T2- and diffusion-weighted scans, which corresponds to vasogenic and cytotoxic edema, respectively. The medial medulla is most often described as being supplied by the anterior spinal artery. The medial medullary syndrome, also known as Dejerine syndrome, is caused by infarction of this region. It […] [...]

Acute superior cerebellar artery (SCA) infarction

Acute superior cerebellar artery (SCA) infarction, with an accompanying small unilateral pontine infarct. Hypodensity is seen on CT in a portion of the SCA territory, with hyperintensity on axial T2-weighted MR (and sagittal FLAIR), both due to vasogenic edema. The presence of restricted diffusion is confirmed on the ADC map, reconstructed from the diffusion scans. […] [...]

Early subacute infarct along the lateral ventricle, in a patient with extensive chronic small vessel white matter ischemic disease

A large lacunar infarct is seen in the white matter of the corona radiata, immediately adjacent to the left lateral ventricle. The infarct demonstrates both vasogenic edema, seen with abnormal high signal intensity on the T2-weighted scan, and cytotoxic edema, seen as restricted diffusion (low intensity) on the ADC map. Thus, the lesion is early […] [...]

Early subacute pinpoint cortical infarct, left precentral gyrus

The patient presented 6 days prior to the MR exam with right arm and facial paralysis. NIHSS=3 (minor stroke), which improved to 0 (no stroke symptoms). CT at the time of symptom onset was negative. Multiple small focal areas of gliosis or edema (with high signal intensity) are seen on the coronal FLAIR, with a […] [...]

Gyriform hyperdensity in a large left MCA and watershed territory infarction, due to prior DSA and not hemorrhage

The patient presented with signs of a large acute left MCA infarct, and proceeded to DSA. The images on the top row were acquired within hours following DSA, and show gyriform hyperdensity in the left MCA and watershed distributions, including the left caudate head. By imaging appearance alone, this could represent either hemorrhage or residual […] [...]

Late subacute, enhancing PICA infarct

There is slight hyperintensity on DWI, which proved to be T2-shine through (not true restricted diffusion) in a portion of the arterial territory of PICA on the right. Hyperintensity is noted on the axial FSE T2-weighted scan in this region, with only subtle increased signal intensity on the coronal FLAIR. On the post-contrast coronal scan […] [...]

Late subacute, enhancing PCA distribution infarcts, secondary to dissection of the right vertebral artery

Edema is seen in the thalamus, high signal intensity in the hippocampus on DWI (principally T2 shine through), and abnormal enhancement post-contrast in these regions together with the medial occipital lobe (all on the right). CE-MRA reveals the right vertebral artery to be narrowed in its midportion, with a small pseudoaneurysm at the level of […] [...]

MCA with accompanying ACA infarcts

At presentation (upper two images), on the unenhanced CT only a small chronic white matter infarct is noted in the left frontal lobe. CTA (thick MIP) reveals a paucity of vessels in the left ACA and MCA distributions. The CT one day later (lower two images) reveals abnormal low density in both the ACA and […] [...]

New infarction bordering a chronic infarct, in an 89-year-old patient

The axial FLAIR and FSE T2-weighted scans reveal extensive chronic deep white matter ischemia (with abnormal mild hyperintensity), together with generalized cortical atrophy and more focal atrophy in the left MCA posterior division, reflecting a prior chronic infarct. There is also abnormal high signal intensity adjacent to the largest area of cystic change, which could […] [...]

Small acute cerebellar infarct

Small acute cerebellar infarct, superior cerebellar artery (SCA) distribution. A portion of the SCA territory is noted to be involved on the left, with abnormal high signal intensity on both T2- and diffusion weighted scans. The high signal intensity on T2-weighted scans denotes vasogenic edema, with the findings on DWI – specifically restricted diffusion, confirmed […] [...]

Small acute left MCA infarct

Small acute left MCA infarct, with severe chronic small vessel white matter ischemic disease. The CT reveals only severe, bilateral, chronic ischemic disease (with abnormal low attenuation), which is also well seen on the FLAIR scan from the MR exam (with abnormal high signal intensity). The diffusion weighted scan enables detection of a small acute […] [...]

Subacute PICA infarct

There is abnormal high signal intensity on T2- and diffusion-weighted axial scans in the left PICA territory. The ADC map however does not demonstrate restricted diffusion, thus identifying the findings on DWI to represent “T2 shine through”. The absence of a true diffusion change dates the infarct to be more than 1 week old, thus […] [...]

Subacute PICA infarct (including AICA)

Subacute PICA infarct, which also includes the AICA territory. Sagittal and axial CT sections reveal abnormal low attenuation in both the PICA and AICA territories (the inferior cerebellum). Note that the tonsil is involved (visualized on the axial CT exam), which is part of the PICA territory. On MR, there is abnormal high and low […] [...]

Utility of B0 images and BLADE, for T2-weighted scans in uncooperative patients

A multishot DWI with b=1000 reveals an infarct involving the left caudate head that age wise is < 7-10 days (demonstrating restricted diffusion, which was confirmed on the ADC map, not show). The b=0 image is slightly less blurred, on the basis of patient motion, given that this is a single image acquisition, as opposed […] [...]

Evaluation of a Modified Stejskal-Tanner Pulsing Scheme for DWI Allowing a Marked Reduction in Echo Time at 3 T

To evaluate a modified Stejskal-Tanner diffusion gradient pulsing scheme that achieves a markedly shorter TE, by applying diffusion encoding during the entire time between the two requisite radiofrequency pulses, with respect to SNR, overall diagnostic image quality, bulk susceptibility artifact, and resulting spatial distortions (which were quantified). [...]


SNR and Parallel Imaging Improvements Offered by a 32 Channel Head Coil Design Advanced head coil design with 3 T imaging substantially improves the available signal-to-noise ratio (SNR), making possible a significant reduction in scan time, the use of advanced parallel imaging, high spatial resolution imaging (reduced voxel size in 3D acquisitions, whether for imaging of the brain itself or the vasculature) and implementation of innovative imaging techniques. The use of higher parallel imaging factors in conventional diffusion-weighted echoplanar imaging (EPI), together with the implementation of a fast spin echo (FSE) based BLADE diffusion-weighted scan is illustrated in patients with acute infarction (the latter free of bulk susceptibility artifact and geometric image distortion). [...]