2 small abscesses

Immunocompromised patient presents with ring-enhancing subcortical expansivities with perifocal oedema. MRI was performed (not shown) suggesting 2 small abscesses. Patient was set on antibiotics.

Control MRI after one month shows on axial T1 without- and with contrast slightly decreased size of ring enhancing expansivities.

Both small abscesses are still enhancing.

There is still perifocal vasogenic edema seen on axial FLAIR and T2 weighted sequences. Note on T2 a well defined low signal rim of the abscesses.

Diffusion weighted imaging showing central diffusion restriction (high signal on DWI and low on ADC-map).

Numerous pathologic entities show as ring-enhancing lesions therefore it is important to include patient's history in evaluation. Here the biggest clue is restricted diffusion. However hemorrhage can also show restricted diffusion due to high protein content as well as rim of hemosiderin on T2.

You can also check my other cases related to this topic:

Abscess and Subdural …

101 years old brain

Yes, as you can see in the title this (female) person is 101 years old. I wanted to show those images as an example of "successful aging". There is some cortical atrophy (GCA 2), some temporal atrophy (MTA 1 right and 2-3 left) as well as some central atrophy and slight atrophy in corpus callosum. Brainstem and cerebellum show no significant signs of atrophy. There is an old lacunar infarction medially in the left thalamus and some ischemic changes in the anterior parts of the left internal capsule but without signs of extensive microvascular disease. By simply looking at the brain I would estimate the age at about 80. BTW. It is known that the atrophy tends to progress in logarithmic and nonlinear fashion - meaning that you see more progression of atrophy in advanced age compared to less change in the younger ages - as a general rule of aging. However of course there are exceptions to this rule.

Cytotoxic Lesions Of the Corpus Callosum (CLOCCs)

45 years old patient on antiepileptic (lamotrigine) and antidepressant medication. Presents with unspecific neurological symptoms. MRI without contrast shows diffusely demarcated oval lesion with edema in splenium of corpus callosum.

Diffusion weighted imaging shows restricted diffusion with high signal on DWI and low on ADC corresponding with cytotoxic edema. However location is not specific for infarction. Given the history of treatment together with appearance of the lesion the Cytotoxic Lesions Of the Corpus Callosum (CLOCCs) was presumed to be the most likely diagnosis. CLOCCs do no enhance. Medication was stopped and follow up scan was scheduled.

Control scan 1 month later was performed without and with contrast and as expected no contrast enhancement was seen. The lesion has decreased in size. Patient symptoms have resolved.

Reduction of edema in the lesion is well seen on T2 sequence.

As a side note: the control scan was performed on 1.5T vs 3.0T MRI scanner for initial exam -…

Calcified Thoracic Disc Herniation

Large left sided paramedian calcified thoracic disk herniation. Note calcifications also present anteriorly in the annulus fibrosus at this level that has reduced disk height. CT was performed 5 years prior.

Current MR (sag STIR and axial T2) showing mostly unchanged disk herniation with low signal on both sequences, but fortunately without spinal stenosis - visible spinal fluid around medulla. The slightly high signal in medulla on sag is an artifact. Calcified thoracic disk herniations pose problem for surgeons when are causing spinal stenosis and requiring operation. It is common that thoracic disk herniations calcify. Should not be confused with meningioma. Thoracic spine being part of thoracic cage is more rigid and stable than more flexible cervical and lumbar spine - so the herniations tend to progress less than on other spinal levels.

Sinus Thrombosis - 9 days old neonate - MRI

9 days old neonate. Mother known with sinus thrombosis during pregnancy. This is T1 without contrast showing high signal of methemoglobine in sinus rectus, superior sagittal sinus and cavernous sinus - representing massive blood clots of sinus thrombosis.

SWI sequence is showing low signal of hemosiderine deposits in central veins. T2 sequence is showing clot filled occipital part of sagittal sinus. ToF MRV (flow based venous angio) shows corresponding flow defects, same on MRV MiP reconstruction.

DWI and ADC-map showing ischemia in the basal ganglia, corpus callosum and corona radiata frontally. Those ischemic changes can be reversible in case of sinus thrombosis (venous infarcts). Major risk are the possible brain hemorrhages - that are fortunately not present in this case.

Teaching point is to look very carefully at non-contrast T1 of neonate for possible high signal changes representing methemoglobine products, not only in dural sinus but also in the subarachnoidal spaces for pos…

Active MS plaques on DWI

This is MS patient with contrast enhancing plaque. Note on DWI sequence high signal as well as high on ADC - therefore no restriction but bright on DWI. DWI gives a clue to active plaques.

MS plaques showing highest signal on DWI are most suspect for activity - in my opinion. Therefore look at DWI (b1000) when reporting brain MRI of MS patients.

CLIPPERS - Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids

T1 GD+ sequences show multiple punctate and linear enhancing lesions in pons and medulla oblongata representing perivascular enhancing lymphatic tissue.

Enhancing punctate lesions are also present in corona radiata on both sides. FLAIR sequence showing corresponding white matter lesions that however present no significant oedema.

Findings represent CLIPPERS - Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids. Rare entity caused by infiltration of the brain with inflammatory cells in perivascular areas, mostly found in brainstem.

More comprehensive description of CLIPPERS in Radiopaedia