Spondylolysis

-

When you see spondylolisthesis (minimal in our patient) you might suspect (usually bilateral) spondylolysis. This is often not the case as spondylolisthesis can also be due to displacement in the facet joints. However it is wise not to miss the spondylolysis. It is rather easy finding on CT - as you can see above. There is no problem judging spondylolysis from normal facet joints. However nowadays we mainly perform MRI for spinal problems.


On MRI it is not that easy to find spondylolysis. This is mostly due to more horizontal angle of the fractures compared to vertical angle of the normal facet joints as seen on transversal images. The sagittals are not always that helpful as well. The clue is that spondylolysis looks like 'additional joint' that should not be there. Note on the images above spondylolysis as well as normal facet joint with cartilage seen on the last image (long arrow). This is the same patient as shown on CT therefore it is good to compare those two diagnostic methods.


Popular posts from this blog

Huntington Disease

-
Image
10 years old boy from parents being cousins to each other presents with progressive rigidity and dystonia. Initial MR showing significant bilateral atrophy in caudate nuclei and putamina with high signal on FLAIR and T2 consistent with gliosis. Note striking symmetric atrophy of the putamina and caudate nuclei on T2 and IR. Huntington disease (HD) is also known as Huntington chorea. HD is an autosomal dominant chronic hereditary neurodegenerative disorder with complete penetrance [Osborn].  Aggregates of huntingtin protein accumulate in axonal terminals, which eventually leads to the death of medium spiny neurons. Autopsy shows generalized cerebral atrophy with an average of 30% reduction in brain weight. Both the cortex and hemispheric WM are affected. The most characteristic gross abnormality is volume loss with rarefaction of the caudate nucleus, putamen, and globus pallidus [Osborn].  Microscopically, HD features neuronal loss with huntingtin nuclear inclusions, astr
Read more

Hemorrhagic Choroid Plexus Cyst

-
Image
Transversal Diffusion Weighted sequence shows high signal in the left choroid plexus with corresponding low signal on ADC (restricted diffusion). Finding represents acute Hemorrhagic Choroid Plexus Cyst . It is also known as Choroid Plexus Xanthogranuloma . Gradient Echo sequence (third image) shows low signal in the right choroid plexus representing hemosiderine deposits after previous hemorrhage. Coronal T1 shows intermediate to high signal in the plexus cyst. Note also low signal in the right plexus on T2 (old hemorrhage) and high signal on FLAIR in the left plexus (acute hemorrhage). Choroid Plexus Cysts are very common normal finding. Those often show restricted diffusion. However in our case of patient with hypertension this finding is of interest to the clinicians as a requirement to more closely monitor patient's blood pressure. There were no signs of intraventricular hemorrhage.
Read more

Dilated Perivascular Spaces in the Brain

-
Image
Above images (tra T2, tra FLAIR, cor T2 and sag T1) show enlarged Perivascular Spaces (PVS) in the right frontal lobe of the elderly patient with dementia. Note that signal follows that of the CSF (see FLAIR). Moreover note moderate general cortical atrophy. PVS, also known as Virchow-Robin spaces are considered normal finding although perhaps in the future we should know more about the exact patophysiology and possible relations till dementia and other conditions.
Read more