Sunday, 29 December 2013

Lhermitte Duclos disease MRI

MRI Brain T2w images show a well demarcated hyper intense lesion in right cerebellum with striations ("corduroy" sign). Despite of its size results in little mass effect.

Lhermitte-Duclos disease (Dysplastic cerebellar gangliocytoma)

• Cowden syndrome (CS) ~ multiple hamartoma syndrome, multiple hamartoma-neoplasia syndrome.
o Hamartoma of cerebellum.
o Hamartoblastoma.
o Granule cell hypertrophy, granulomolecular hypertrophy.
o Diffuse ganglioneuroma of cerebellar cortex.
o Neurocytic blastoma.
o Myelinated neurocytoma.
o Purkingeoma.

Dysplastic cerebellar gangliocytoma (LD) is a rare tumour of cerebellum.
Grading WHO grade 1 tumor.
Varies in size and extent, always occur in cerebellum.

Imaging findings: 
Generally affects one hemisphere but commonly extends to vermis, as a well demarcated area of abnormal low density on CT / T2 hyper intensity on MRI with striations ("corduroy" or "tiger-striped" pattern).
No edema.
Usually little mass effect.
No restricted diffusion on MRI Diffusion.
No enhancement on post contrast. Very rarely mild enhancement.
MRS Reduced NAA, decreased to normal Choline, raised Lactate.

Histopathological findings: 
Gross pathologic and surgical features includes markedly enlarged cerebellar hemisphere/vermis with thick folia, Pale appearing mass.
Microscopic features includes widening of molecular cell layer ~ occupied by abnormal ganglion cells, Absence of Purkinje cell layer, Hypertrophy of granule cell layer, decreased volume of white matter.
Histologically may be confused with ganglion cell tumor

Clinical Presentation: 

Signs/symptom are often vague related to raised intracranial pressure, brainstem and cerebellar findings (cranial nerve palsies, ataxia), hydrocephalus.
Onset of symptoms most common during 3rd-4th decades of life
Age and Gender:
Any age, birth-60 years, more common between 30-40 years.
M = F / M >  F

LD is very rare, all patients must be screened for CS.
Cowden syndrome is a hereditary hamartoma-tumor syndrome ("phakomatosis") characterized by
1. LD in brain,
2. Mucocutaneous lesions,
3. Multiple hamartomas/neoplasias in breast/thyroid,
4. Gastrointestinal tract polyps,
5. Genitourinary malignancies,

Clinically CS include:
Benign breast, skin lesions
Oral papillomas,
Benign thyroid lesions (adenomas),
Gastrointestinal tract polyps/hamartomas,
Genitourinary neoplasias.

Surgical resection in symptomatic patients
Borders of lesion blend into normal surrounding cerebellum may cause total resection difficult.

Saturday, 28 December 2013

Focal Adhesive Arachnoiditis of Spinal Cord

A 35 y o male with both lower limb weakness.
History of meningitis in the past ~10 years back.
History of major trauma ~7 years back. 

MRI whole spine with contrast
This MRI study of whole spine with contrast shows:
Multiple loculation in the the Csf space anterior to cord in dorsal region iso intense to Csf. 
Changes of myelomalacia with cavitations.
No abnormal cord or lepto meningeal enhancement on post contrast. 
Lower cord and conus spared, Conus pulled up owing to upward traction. 
Multiple rib fractures on either side. 
Cauda equina normal. 

Imaging diagnosis: Focal Adhesive Arachnoiditis of the Spinal Cord with Myelomalacia. 

Focal Adhesive Arachnoiditis of the Spinal Cord

Adhesive arachnoiditis may result in the formation of syringomyelia or myelomalacia, causing neurological deterioration such as sensory disturbances in the extremities, urinary disturbance, or sexual dysfunction.
Basic studies suggest that spinal tissue scarring at the injury site may cause a tethering effect on the spinal cord, which may lead to significant alterations in CSF dynamics. It is speculated that the rostro caudal CSF pulse wave is misdirected into the spinal cord parenchyma. The resulting high intramural pressure and decreased compliance of the subarachnoid space favor the flow of fluid into the spinal cord, possibly through perivascular spaces, resulting in a destructive cavitation process and eventually the formation of a syrinx cavity.
Causes of Adhesive arachnoiditis include hemorrhage, infection, trauma, radiation necrosis, ischemic infarction, or surgery.

Adhesive Arachnoiditis and Foix-Alajouanine Syndrome 

Modern understanding of the non-infectious neuropathologic entity "adhesive arachnoiditis" began in 1926 with the publication "La Myélite nécrotique subaiguë (Myélite central angiohypertrophique évolution progressive) Paraplégie amyotrophique lentement ascendan d'abord spasmodique, puis flasque"  by authors C. Foix and T. Alajounanine in the French Revue Neurologique (Paris), 2: 1-42).

What these authors described were cases which, in all probability, represented primary spinal cord Arterio Venous malformations producing recurrent subarachnoid hemorrhage.  A-V malformations represent congenital abnormalities of blood vessel development.  They are collections of abnormal and flimsy blood vessels which shunt blood directly from arteries to veins. Because these blood vessels are so fragile they are likely to spontaneously bleed on an intermittent basis.

The subarachnoid space represents the "salum sanctorum" of the human body.  It abhors all foreign body substances.  Even the presence of injected air is considered to be a "foreign body."  Blood is definitely considered a foreign body (particularly the breakdown products of blood ).  Repeat exposure to foreign body substances in the subarachnoid space can initiate auto-immune amnestic reactions which may potentiate and magnify the ongoing inflammatory process leading to severe local arachnoid fibrosis, associated thrombosis of local blood vessels, progressive destruction of the spinal cord producing myelomalacia and cystic degenerations in cord.

Initially the Foix-Alajouanine pathologic entity was only an autopsy phenomenon until the advent of high resolution MRI and associated modern spinal angiography.  This entity was mainly a medical curiosity until the midpart of the 20th century when some clinicians took a special interest in this entity. David B. Clark, neurologist at the Johns Hopkins Hospital was one of these pioneers.  With better neuropathologic definition combined with more astute clinical observation the Foix-Alajouanine Syndrome (FAS) became part of a patient's differential diagnosis.

FAS usually occur in the thoracic spinal cord in "watershed" zone of the thoracic spinal cord.  Because this spinal area has the most tenuous arterial blood supply it is most prone to injury when its vascular nourishment becomes impaired.  The remittent leakage of blood from the A-V malformation promotes slowly progressive local arachnoid fibrosis (adhesive arachnoiditis) which physically and physiologically "chokes" the spinal cord.

Because the changes are slow the patient may not experience any neurologic symptoms until some event produces a situation akin to "the straw that broke the camel's back."  most individual afflicted with adhesive arachnoiditis have few in the way of clinical symptoms.

Focal Adhesive Arachnoiditis and Lumbar Puncture

We live in a medical era still characterized by lumbar puncture routinely utilized for the following purposes like Initiation of spinal anesthesia, Diagnostic taps to obtain spinal fluid samples, i.e. to rule out meningitis. It is not unusual for patients to experience, as a complication of spinal tap, continued leakage of cerebro-spinal fluid producing postural headache, lightheadedness and inability to function due to these complaints.  The commonly employed treatment for this is a "blood patch."  Blood drawn from a vein is purposely injected into the supposed epidural space as a means of "patching" the leaking fluid. Appropriate blood patches routinely introduce some blood into the subarachnoid space and inappropriate ones may introduce as much as 10-12cc of blood directly into the subarachnoid space. How much blood, introduced how often, is necessary to create adhesive arachnoiditis?  This question has not yet been answered.  We only know at this point in time, that blood, and its breakdown products, can serve to create adhesive arachnoiditis and  the introduction of any foreign body substance (for any purpose) into the subarachnoid space is not a wonderful idea.

The diagnosis of the syndrome of Foix and Alajounanine (FAS) can occur only when the clinicians involved in the case know that this entity exists and also understand adhesive arachnoiditis as a pathologic entity.  Even at the start of the new millennium few radiologists or clinicians possess this awareness.


When the spinal cord is damaged as a result of trauma, there is often bruising or bleeding from the cord itself, either as a result of tearing of surface vessels by stretch, or by physical damage from bone fragments.  This bleeding then can lead to scar formation between the spinal cord and the inner surface of the canal, known as the dura.  When this scarring occurs, the deformity can cause further loss of neurological function or pain, often in a delayed fashion, sometimes 10-20 years later.  When this occurs, the tethering can be cut so that the cord no longer is being tugged on with every movement of the body, and this can relieve or improve the symptoms.


Various surgical procedures, including cerebrospinal fluid (CSF) shunting or subarachnoid reconstruction, are available.
Shunting of CSF from the syringomyelia to the subarachnoid, pleural, or peritoneal space has been proposed to resolve the propagation of the syringomyelia or myelomalacia, but the effect of the procedure is not long lasting and revision surgery is needed rather frequently.
Microsurgical dissection of the arachnoid adhesion, with decompression of the subarachnoid space, is another approach and may achieve better and more long-lasting outcomes in selected cases.

Thursday, 5 December 2013

Posterior fossa cystic mass MRI

A 14 yo female with headache, vomiting.
Signs of raised ICT.

This MRI study shows:
A predominantly cystic lesion with thin wall in the region of cerebellar vermis with eccentric avidly enhancing solid nodule at its cranial portion extending in pineal region.
Mid brain Pons compressed. Fourth ventricle is seen anteriorly and separately compressed leading to mild obstructive hydrocephalus.

Imaging diagnosis given was Pilocytic Astrocytoma.

Operated with sub occipital craniotomy.


Specimen : Excisional biopsy Vermian SOL.
Gross appearance : The specimen consists of multiple irregular soft to friable pieces of dull grey tan tissue together measuring 30x30x10mm The cut section through the larger pieces appear grey tan fieshy. The entire tissue submitted for processing.
Microscopy : Sections A and B shows Astrocytic neoplasm of probable pilocytic differentiation. The tumour comprises of cellular areas consisting of relatively monomorphic round oval to elongated fibrillated cells with scanty eosinophiillic cytoplasm seen to be arranged in sheets with intervening loose spongy tissue showing prominent microcysts and occasional macrocysts with numerous congested micro vascular proliferative vessels. In couple of foci the neoplastic tissue shows presence of ganglionic cells and few cells with Resenthal fibers. Overall the entire neoplasm shows scattered eosinophillic granular bodies, few mitosis and foci of tumour ischemic coagulative necrosis.

Histopathological diagnosis: Pilocystic Astrocytoma _ Pilomyxoid variant, Grade ii as per WHO grading. 


Synonym: Polar spongioblastoma.
Astrocytic precursor cell tumor.
Contributes 5-10% of all gliomas.
Most common primary brain tumor in children. More than 80% are under 20 y, Peak incidence: 5-15 years of age, Gender: M = F.

Has syndromic association with NF 1.
15% of NF 1 patients develop PAs, most commonly in optic pathway.
Up to 1/3 of patients with optic pathway PAs have NF 1.

Cystic cerebellar mass with enhancing mural nodule is diagnostic clue.
Overall morphology often determined by cystic Component.
Cerebellum is most common (60%) > optic nerve/chiasm (25-30%) > adjacent to 3rd ventricle > brainstem.

Imaging findings:
Discrete cystic /solid mass, may have little or no surrounding edema.
Solid component variable density on CT and signal intensity on MRI, enhance strongly as enhancing mural nodule in more than 95%.
Non enhancing cyst in ~ 50% cases. Cyst may accumulate contrast on delayed images.
Associated calcification in ~ 20%, hemorrhage rare.
Rarely tumor may spread through subarachnoid space (but is still WHO grade I)
MR Spectroscopy is aggressive appearing metabolite pattern, high choline, low NAA, high lactate

Frequently causes obstructive hydrocephalus, may be a greater clinical management problem than tumor itself.
Most common signs/symptoms are Headache, nausea and vomiting, Ataxia, Cerebellar signs.

Adjuvant chemotherapy or radiation only if residual, progressive, unresectable tumor.

Medulloblastoma (PNET-MB)
• Hyperdense enhancing midline mass fills 4th ventricle
• Younger patient age (2-6 y)
• "Plastic" tumor, extends out 4th ventricle foramina

• Ca++, cysts, hemorrhage common; heterogeneous enhancement.

Similar Case :

Sunday, 1 December 2013

Joubert Syndrome CT Brain

Molar tooth shape of mid brain with bat wing shape of fourth ventricle 

First identified by Dr Marie Joubert, Montreal, Canada, Pediatric neurologist.
A rare genetic disorder that involves areas of the brain that controls balance and coordination.

Characterized by absence or underdevelopment of cerebellar vermis and a malformed brain stem
'Molar tooth' sign - molar tooth shape of mid brain on axial sections and bat wing shape of fourth ventricle.

Clinical features:
Ataxia Most common, hyperpnea, sleep apnea, abnormal eye and tongue movements and hypotonia.
May be associated with other malformations like polydactaly, cleft lip or palate, anomaly of tongue.
Mental retardation.
Joubert is one of the many other genetic syndromes which are associated with syndromic retinitis pigmentosa.

Treatment is symptomatic and supportive like Infant stimulation, physical, occupational, and speech therapy.Infants with abnormal breathing patterns may need respiratory support and monitoring.

Similar Case : Joubert-syndrome MRI

Spinal epidural lesion causing cord compression MRI

A 15 yo female with bilateral lower limb weakness.
Compressive myelopathy clinically.
MRI Dorsal spine performed with contrast.
Non contrast T1
Post contrast T1
Axial T2
Axial Post contrast T1
D7 vertebral body and adjacent posterior elements show an abnormal altered marrow signals, heterogeneously hyper intense on T2 and STIR with low signal intensity vertical striations on sagittal sections, multiple punctate low signal intensity dots on Axial T2w sections so called as 'Polka dot' appearance corresponds to coarse, thickened vertical trabeculae characteristic of Spinal Osseous Hemangioma.
An associated posterior epidural lentiform shaped soft tissue with intense homogeneous enhancement on post contrast T1 causing canal stenosis, anterior displacement of cord with significant cord compression.

Imaging wise possible diagnosis : Aggressive vertebral Hemangioma with significant cord compression. 

Patient operated, cord decompressed by complete excision of posterior epidural soft tissue by Laminectomy. Tissue subjected for histopathology.


Specimen: D7 vertebral lamina and spinous process with epidural soft tissue.

Gross Appearance : The specimen consists of grey brown soft and largely bony fragments together measuring ~ 25x14mm. Representative sections are submitted for processing after de calcifying bone.

Microscopy : A benign neoplasm composed of vascular tubes or spaces lined by endothelium and many containing blood. The interstitial tissue contains a couple of spicules or trabeculae of bone.

Histopathological Diagnosis : Spinal Intraosseous Hemangioma. 

Vertebral body hemangioma are usually benign looking and asymptomatic.
Rarely aggressive and pt may present with cord compression due to an associated epidural soft tissue as in this case. 

Thursday, 28 November 2013

Calcification of trochlear apparatus of orbit

A 50 yo female with left side weakness advised Non contrast CT for Brain to rule out any intra cranial bleed or infarction.


No bleed or infarct on CT study of Brain.

A dense nodular calcification noted in the superior-nasal quadrant of the right orbit. Clinically right eye vision and movement normal.  No history of trauma to right eye.

Final diagnosis:

Unilateral calcification of trochlear apparatus of right orbit_ noted an incidental finding.

Calcification of trochlear apparatus of Obit.

Syn: Calcified Trochlea of the Superior Oblique Muscle.

The trochlear apparatus of the eye is a cartilaginous structure with a synovium lined sheath that permits unimpeded movement of the superior oblique muscle.

It is not clear yet the accurate location of calcification whether its cartilage, the synovial sheath, or the tendon.

Hart et al. in his study reported an association between calcification of the trochlear apparatus and DM, reviewed some 159 CT scans of patients and observed trochlear calcifications in 12% of patients with a significant correlation between diabetic patients under 40 years of age and the presence of calcification in the trochlear apparatus. The trochlear calcification on CT is a benign condition may serve as a marker for diabetes in young patients. Trochlear calcifications are observed frequently in persons more than 50 years old. When it is present in patients younger than 40 years, it is strongly associated with diabetes.
Another thing which is observed in these studies is trochlear calcifications were more prevalent in male patients and none of the patients in these studies had symptoms related to their trochlear calcification.

Studies conducted later, results were In contrast to the findings of Hart et al, did not find a significant correlation between patients under 40 years of age with DM and the presence of trochlear apparatus calcifications. Even there was no increase in trochlear calcifications with advancing age or the presence of systemic disease indicating that trochlear calcifications is not suggestive of a degenerative process and occur regardless of chronic medical disease.

Left parietal cyst MRI

MRI findings:

A left temporo parietal cystic lesion.
Lesion is multi locular, its difficult to mention whether the lesion is intra axial or extra axial as it is insinuating in brain parenchyma.
Content of cyst is clear fluid, iso intense to Csf.
No restricted diffusion on Dw images.
Lesion has thin imperceptible wall.
No solid component.
No peri lesional odema.
Significant mass effect_ mid line shift with sub falcine as well as uncal herniation. Mid brain compression.

Imaging wise possible DDs : Arachnoid cyst >  Neuroglial Cyst.

Pt operated, left parietal craniotomy with complete excision of lesion.

Histopathology Report

Specimen : Excisional biospy.
Gross appearance : The specimen consist of soft wrinkled pieces of dull grey white tissue _ cyst wall.
Microscopy : Sections shows a benign cystic lesion comprising delicate membranous fibrous connective tissue cyst wall lined by meningothelial cells, at places seen to form focal aggregates. There is no evidence of cytological atypia.

Final Diagnosis : Arachnoid cyst. 

Sunday, 10 November 2013

Congenital Bilateral Perisylvian Syndrome MRI

This MRI brain axial T2w image shows bilateral deep wide vertically running clefts in the region of Sylvian fissures lined by thick gyri.

Imaging diagnosis : Congenital Bilateral Perisylvian Syndrome.

Syn :
Opercular syndrome,
Foix-Chavany-Marie syndrome,
Worster-Drought syndrome,
Bilateral symmetrical polymicrogyria

The term “perisylvian” refers to the area (“peri” = about or around) of the sylvian fissure (lateral sulcus), which acts as the brain’s language and speech center. It is basically an organization anomaly in which the neurons reach their final destination in the cortex but are distributed abnormally.

The syndrome is one of a group of congenital neurological diseases characterized by slack muscles of the face and tongue, chewing and swallowing difficulties, delayed or abnormal speech and language development, epilepsy, and in certain cases, impairment of cognitive function and impaired mobility. Similar disorders were described first by the French neurologists Charles Foix, Jan Alfred Chavany and Julien Marie in 1926, and later by the English physician Cecil Charles Worster-Drought in 1956.

Genetic factors are very important, and there are families in which more than one person has the syndrome, although the symptoms may vary from person to person. Linked with a mutation on the long arm of the X chromosome (Xq27.2-q27.3 and Xq28). Disorders caused by mutations in genes on the X chromosome primarily affect boys.
Acquired, the Perisylvian syndrome may also be acquired, for example from a local malfunction in the blood circulation of the brain, or an infection in the relevant area of the temporal lobe during the foetal stage like congenital cytomegalovirus infection. In these cases the condition is not hereditary.

Clinical presentation:
The most common symptoms are impairments of the mobility of the tongue and throat (pseudobulbar palsy), epilepsy and mild cognitive impairment.
In serious forms of the disease, neonates may have problems sucking and swallowing.
May not become apparent till the child starts eating solids. It can be difficult to chew, move food around in the mouth, and swallow. Drooling is common.
Child is slow to start talking or has speech difficulties. The most common symptoms are paralysis or impaired motor capacity of the organs necessary for speech (dysarthria) and difficulties coordinating movements (dyspraxia) of the mouth.
Unclear and slurred speech, as well as problems forming certain sounds, are signs of dysarthia whith as associated drooling and swallowing difficulties. Problems in moving the tongue and the mouth mean that children with the syndrome cannot purse their lips or whistle. Oral motor problems, which commonly cause difficulties eating, drinking and speaking, remain throughout life.
Oral motor problems may affect the growth of the lower jaw, which may be smaller than normal (micrognathia). Misalignment of the teeth (malocclusion) may mean that it is difficult to close the mouth completely and that the lower jaw protrudes.
Dyspraxia may be oral or verbal. Oral dyspraxia means that it is difficult to exert voluntary control over movements of the tongue and lips. Verbal dyspraxia means that it is difficult to form words, despite the relevant organs having normal functionality. The symptoms are the result of abnormalities in areas of the brain controlling the motor skills necessary for speech. In verbal dyspraxia it is difficult to make a connection between sounds and syllables, which is necessary to form words. The degree of severity varies. Less severe disabilities give rise to problems with multi-syllable and longer sentences, which become more difficult to formulate the longer they get. Severe dyspraxia may mean that the child cannot form syllables or words.
Other language and communication problems may also occur, including difficulties with grammar and phonology (speech sounds). Children with the syndrome may have specific reading and writing problems (dyslexia). Speech comprehension, however, does not appear to be affected.
Most individuals with this syndrome have epilepsy. Seizures may present as infantile spasms during the child’s first two years of life and develop into other, difficult to treat, forms of epilepsy as the child gets older. In infantile spasms the child experiences a series of short, sudden, cramp-like jerks of the arms, or wider, uncontrolled movements of the arms.
Physical disability characterized by stiffness in the arms, legs and neck. Stiff, malformed joints make it difficult to walk, and to move in general. Require special aids or a wheelchair.
Mild cognitive impairment and hyperactivity may also present. Individuals with intellectual disability require more time to understand and learn new skills.

The diagnosis is based on observation of the symptoms, as well as finding structural abnormalities on CT and MRI.

Treatment and Rehabilitation: 
There is no cure for Perisylvian syndrome.
Training in oral motor skills and swallowing at an early stage.
Exercises to the muscles of the tongue.
Training in closing the mouth will help prevent deformities of the lower jaw.
Child may need to be fed with the help of a PEG (percutaneous endoscopic gastrostomy), a procedure where a feeding tube is inserted into the stomach directly through the abdominal wall.
Their epilepsy is often difficult to control as the nature of the attacks varies greatly. Medication is prescribed on the basis of type of seizure, EEG results and the effects of the medication.
Surgery may sometimes be used to control epileptic attacks. A vagus nerve stimulator can be an alternative if other measures fail. The vagus nerve is one of the twelve cranial nerves originating in the brain. In an operation the stimulator is placed under the left collar bone and it sends electric impulses to the brain with the help of an electrode placed around the vagus nerve in the neck. These impulses can reduce epileptic activity and attacks.
Speech therapist to assesses and treats chewing and swallowing problems, drooling and communication difficulties.
Treatment usually requires mutli-disciplinary teamwork. The major hospitals in Sweden have specialist teams (dysphagia and nutrition teams) for assessing and treating speech, eating and swallowing difficulties.
Dental treatment for chewing and oral hygiene in the form of dental braces.

Spinal Drop Metastasis from Choroid Plexus Papilloma MRI

A 16 y o female patient, known case of posterior fossa mass _ Operated 2 years back.
Here are few snaps of Pre operative MRI Brain images showing lesion at the floor of posterior cranial fossa with caudal protrusion through foramen magnum.
Previous histo pathology report noted mentioning it to be Choroid Plexus Papilloma.

Now patient presented with backache and bilateral lower limb weakness, MRI Brain with spine screening done with contrast.
The Post Opeative MRI Brain shows:
E/o mid line sub occipital craniotomy, complete excision of lesion.
No obvious recurrent or residual lesion on post contrast T1.
Complete regression of hydrocephalus.

The Post Operative MRI Spine shows spinal drop metastasis.

Description of findings:

MRI Sagittal T2w images shows an intra medullary lesions in cervical cord, mild expansion of cord, non enhancing on post contrast fat sat T1.
Similar lesions on surface of spinal cord through out its length and completely filling thecal sac in lumbar region, an abnormal enhancement along surface of cord and nerve roots of cauda equina on post contrast fat sat T1 consistent with Spinal Drop Metastasis from Posterior fossa Choroid Plexus Papilloma.


Choroid plexus papillomas (CPPs) are typically considered as benign tumors, with a favorable long-term prognosis. The standard treatment for a CPP is complete surgical resection and is thought to be curative.
Drop metastasis of CPP into the spinal subarachnoid space is rare.
In our case 16 year-old female who presented with back pain and lower limb weakness 2  years after removal of a posterior fossa CPP due to its spinal drop metastasis.
CPP can spread via cerebrospinal fluid pathways and cause spinal drop metastasis. Therefore, it is necessary to evaluate the whole spine in addition to brain, pre operatively as well as with post operative periodic follow-up MRIs in patients with CPP.

Monday, 4 November 2013

Choroid Plexus Papilloma MRI

A 1 y o male with headache, signs of raised ICT. 
On Admission CT followed by MRI Brain with Contrast.

This CT and MRI study of Brain shows an intra ventricular ovoid solid frond like well defined lesion in right lateral ventricle.
Lesion is isodense on CT with faint specks of calcifications.
Restricted diffusion on Dw MRI Images.
Avid homogeneous enhancement on post contrast T1w MRI.
No adjacent parenchymal invasion.

Imaging diagnosis given was Choroid Plexus Papilloma, moderate communicating hydrocephalus due to over production of Csf.


Specimen : Excisional biopsy, right lateral ventricle mass.

Gross appearance : Multiple irregular soft to friable soft pieces of dull gray tan tissue, together measuring ~ 44x4x29mm. The cut section thru the larger piece appears papillary.

Microscopy : Benign neoplasm of probable choroid plexus epithelia comprising predominantly complex and branching neoplastic papillae lined by single layer of low cuboidal epithelia - devoid of significant cellular pleomorphism nor increased mitosis. In few foci the epithelia show focal stratification and crowding. The sub epithelial cord substance of the papillae appears focally odematous with congested blood vessels and sparse lymphocytic infiltrates. There is no evidence of cytological anaplasia.

Histopathological diagnosis : Choroid Plexus Papilloma.

Choroid Plexus Papilloma (CPP)

Imaging findings:
Location wise most common i.e ~ 50% in  atrium of lateral ventricle, left> right, ~ 40%  fourth ventricle.
~ 10%  third ventricle (roof) and ~ 5%  multiple sites.
• Morphology: Well delineated, lobulated intra ventricular cauliflower like mass, frond like surface projection.
Benign, slowly growing tumor often larger at the time of presentation.
Solid density on CT and signal intensity on MRI.
Foci of calcification best seen on CT.
Intense homogenous enhancement on post contrast T1.
CSF seeding of lesions is known.

Clinical Presentation: 
Age: Lateral ventricular CPPs common in infants and children where as fourth ventricular CPPs common in adults.
Most common signs/symptoms are of raised ICT, Macrocrania, bulging fontanelle, vomiting, headache, ataxia.

Imaging wise difficult to differentiate from Choroid plexus carcinoma (CPCA)
Heterogeneous enhancement, invasion of adjacent brain parenchyma goes in favor of CPCA.

Reference : DI Osborn.

Saturday, 2 November 2013

CV Junction Meningioma MRI

A 40 y o female with progressive lower limb weakness. 
On admission MRI Brain and Cervical spine screening done.
This MRI sagittal T2w images and Post contrast fat sat T1w images shows an extra axial solid signal intensity lesion, iso intense on T2w images at foramen magnum causing foramen magnum stenosis and significant cord compression. Intense homogeneous enhancement of lesion on post contrast with dural tailing.

Imaging diagnosis : CV Junction / Foramen Magnum Meningioma.

Saturday, 26 October 2013

Neuroimaging During Pregnancy

During pre, there are some alterations in physiological state of pregnancy which leads to variety of neurological problems.
Pregnant patient with neurologic problems carries both diagnostic and therapeutic challenges.
The physicians often require some form of neuro imaging as part of their ongoing evaluation.

Safety of CT and MRI during pregnancy.
Whenever the imaging study in a pregnant patient is considered, risks to the fetus must be balanced with the health of mother.

CT ?
Off course carries risk of radiation to fetus.
The harmful effects of radiation depend on the stage of gestation, the total dose of radiation, and the rate.
As per animal studies, highest sensitivity appears to be during the period prior to conception when developing embryo has not yet been implanted in the uterus, during these first 2 week there is all-or-nothing effect that is either no effect or demise of the embryo.
During organogenesis, 3rd to 8th wk after conception, risks to the developing embryo is variable ranges from congenital malformations to growth retardation or neonatal death.
During the fetal period of development, 6 weeks after conception to birth, irradiation is unlikely to result in gross malformations. However, may result in mental retardation.
As per available data, the dose required to have mental retardation is 12–20 rad which is far higher than the dose achieved in today’s diagnostic procedures.
The fetal radiation dose during CT Brain of mother is less than 0.01 rad, whereas CT abdomen is 0.25–2.5 rad which is far low.
Some believe than there is increase risk of childhood cancer like leukemia but the figures from recent studies mention that there is extremely small added risk for children of patients who have undergone diagnostic imaging during pregnancy. Even multiple CT of the abdomen would only minimally increase the natural risk of childhood cancer.

Now what if patient is found pregnant after CT study is done? 
1. She should she be informed of the fetal radiation.
2. She and her family needs to counseled that exposure to less than 5 rad …is not associated with definite risk of spontaneous abortion, cong malformations, or mental retardation. This over concern should not prevent medically necessary procedures from being performed.

As far as neuroimaging i e Brain and Spine in concerned MRI often preferable to CT and is considered to be safe during pregnancy.
But one should delay elective MRI if possible as its believed that there is a strong magnetic field, minimal increase in body temperature, and there is lot of noise that may affect developing chochlea of fetus.
Intra venous Contrast ?
The problem is that we don’t have well-controlled studies in pregnant women, but animal studies have failed to show association of teratogenicity or mutagenicity with use of contrast.
However CT contrast is rated as a class B drug where as MRI contrast is rated as a class C drug by the FDA so  better avoid both unless no alternative exists.
Contrast during Lactation ?
Let it be CT or MRI, estimated delivery of contrast from mother to baby via breast milk is extremely low so there is no need to stop breast feeding following CT or MRI Contrast.

Neurologic Diseases Associated With Pregnancy

Pregnancy causes changes in the hemodynamic, endocrine, and hematologic systems, which may predispose to stroke during pregnancy.
Neuroimaging features of stroke are not going to change in pregnant and non pregnant pt.

Cerebral Venous Thrombosis
Presentation is often headache, seizures, encephalopathy, papilledema, or focal neurologic deficits.
MRI is investigation of choice as there is no radiation, its high Resolution and have MR Venography option which is possible without contrast. No need of keeping patient Nil by mouth (NBM).
MRI can elegantly demonstrate thrombosed dural venous sinus or deep cerebral vein. Associated infarction and intraparenchymal hemorrhage.

Thrombosed superior sagittal sinus, note low signal intensity thrombus on GRE.  
Thrombosed right parietal para sagittal cortical veins with low signal intensity thrombus on GRE
 A case of deep cerebral venous thrombosis_ bilateral thalamic venous infarcts. Thrombosed straight sinus not visualised on MR Venogram. 

Preeclampsia and Eclampsia
A multisystem disorder seen in the later stages of pregnancy / in the first 6 to 8 weeks after delivery.
Exact etiology is not clear, but the circulating toxins released from the placenta believed to cause vascular pathology.
Preeclampsia, a less-severe form of the disorder, occurs in ~5% of pregnancies, characterized by hypertension and proteinuria. Clinically usually asymptomatic, may present with headaches, sudden or unusual severe edema, visual changes.
Eclapsia , a severe form characterized by seizures.
MRI findings of preeclampsia and eclampsia are same, the combined term used in imaging diagnosis is Hyper tensive encephalopathy /  Posterior reversible encephalopathy.
MRI Brain axial FLAIR images show bilateral fronto parietal T2 white matter hyper intensities without restricted diffusion, and with normal MR Venogram of Brain which is very typical of  Posterior Reversible Encephalopathy

HELLP, a severe form seen in ~ 10% of patients and is a life-threatening condition characterized by hemolytic anemia, elevated liver enzymes, and low platelet count.
This low platelet count can lead to intra parenchymal bleed without any CVT on MR Venogram.
A typical case of HELLP, low platelet count and raised liver enzymes. 
MRI Brain shows left frontal bleed with left fronto parietal sub dural hematoma. Normal MR Angiography and Venography of Brain, done to rule out any associated vascular malformation.

Postpartum Angiopathy
A reversible cerebral vasoconstriction syndrome involves medium-sized intracranial arteries.
Patient often present with thunderclap headache, acute as well as focal neurologic deficits.
MRI Brain with MR Angio investigation of choice.  No contrast. No NBM.
MRI may demonstrate recent infarcts along border zones. Stenosis / vessel occlusion on MR Angio.
MRI Brain diffusion shows multiple recent infarcts along bilateral cortical border zones. MR Angiography of Brain shows multifocal intracranial stenosis. 

Meningiomas may dramatically increase in size during pregnancy as some of them represent hormonal receptors.
Presentation depends on its size and location, varies from elevated intracranial pressure, visual impairment with optic nerve atrophy to seizure.
A known case of Sphenoid wing meningoma.
Now admitted with recent onset seizures while pregnant, the on admission repeat MRI Brain shows same left side Sphenoid wing meningioma, but this time it was marginally increased in size with marked perilesional odema which was absent in previous MRI. 

Choriocarcinoma with Metastasis 
A malignant trophoblastic tumor.
May occur after a normal pregnancy, or can be seen in the context of abortion, molar or ectopic pregnancy.
Can metastasize to the liver, lung, or in 10% of cases to the brain.
Choriocarcinoma and its mets a highly vascular tumor and therefore very susceptible to bleed.
Presentation may be headache, focal neurologic deficits, seizures, encephalopathy, raised ICT.
A case of Choriocarcinoma with hemorrhagic metastasis in Brain

Pituitary Apoplexy
During pregnancy the pituitary gland tends to grow in size and some time it outstrips its vascular supply leading to hemorrhagic and/or ischemic changes.
Presentation is usually sudden headache, nausea, or vomiting, loss of consciousness.
Due to the close proximity of the pituitary gland to the optic chiasm and cranial nerves III, IV, and VI may present with  multiple CN Palsy.
A case of pituitary apoplexy showing enlargement of pituitary with bleed on MRI mid sagittal non contrast T1w section. 

Sheehan syndrome
A hypopituitarism secondary to severe blood loss and hypo volemic shock during labour resulting in Ischemia and necrosis of pituitary .
On MRI, lack of normal enhancement on post contrast images is a diagnostic clue.
Once bleed or ischemia resolves, on follow-up imaging one may find Empty sella due to loss of tissue volume.
MRI Brain, mid sag T2w sections shows Roomy hypophyseal fossa occupied by Csf. 
Pituitary flat at the floor near posterior wall of sella with an abnormal height less than 2mm.

Lymphocytic Hypophysitis
An autoimmune condition of the pituitary occurs in late pregnancy or the postpartum period due to Lymphocytic infiltration of the pituitary gland, infundibulum.
Enlargement of pituitary gland with abnormal enhancement on MRI is a diagnostic clue.

Wernicke's Encephalopathy
Caused by thiamine deficiency.
Common in chronic alcoholics however pregnant patients with hyperemesis gravidarum due to malnutrition due to nausea and vomiting and increased fetal metabolic demand for thiamine, land up with thiamine deficiency.
A case of Wernike's Encephalopathy, MRI Brain Axial FLAIR images at the level of brain stem shows typical peri aqueductal involvement of mid brain and hypothalamic T2 hyper intensities. 

Characterized by triad of Acute encephalopathy, Ataxia, and Ophthalmoplegia or Coma alone.
With early diagnosis, can be rapidly reversed with IV high dose of thiamine and fatal if left untreated.
MRI is investigation of choice.

Multiple Sclerosis
Commonly affects 20 to 50 Years females i e reproductive  age group.
Nothing specifically different in the neuroimaging of pregnant / non preg MS patients however pregnancy, affect the relapse rate, as relapses decrease in frequency throughout pregnancy  but increase in the postpartum period.
Increased estriols level during pregnancy result in  T2 mediated immune shift in MS.
MRI investigation of choice.
Case of MS, MRI Brain Axial and Sagittal T2w images of Brain showing plaques of demyelination in bilateral fronto parietal peri ventricular white matter, involving corpus callosum. Sagittal T2 w images of spine of same patient shows faint T2 hyper intensities of demyelination involving cervico dorsal cord.

Pregnancy-related Back Pain
Backache is common during pregnancy cause can be  hormone-induced laxity of spinal ligaments, Gravid uterus exerting pressure on the lumbosacral plexus or increased lordosis in pregnancy.
MRI is the best, can visualize spine , spinal cord as well as nerve roots which is not possible with CT.
Better post pone MRI too.
But Strong indications for MRI are cauda equina syndrome, acute weakness, radiating pain, bowel bladder involvement.
MRI may reveal Disc herniation causing cord, cauda equina or nerve root compression and cord demyelination in patient of lower limb weakness.
MRI Lumbar spine sagittal and axial T2 w images at L5-S1 show a left para central disc extrusion causing obvious compression of left traversing S1 nerve root in lateral recess. 
MRI Dorsal spine sagittal and axial T2w images shows a focal disc protrusion causing cord compression.
MRI Cervico dorsal spine, sagittal T2w images show abnormal multi segmental contiguous intramedullary T2 hyper intensity suggestive of cord demyelination. 

Epidural hematoma can occur rarely in association with pregnancy, either spontaneous related to increased abdominal pressure during delivery or as a complication of epidural anesthesia.
MRI Lumbar spine, Sag T1 and T2w images : Case of posterior spinal epidural hematoma causing significant canal stenosis at L2-3 disc level with marked compression over thecal sac and nerve roots of cauda equina. 

As far as safely is concerned MRI is safe than CT. However post pone both CT as well as MRI if possible.
As far as Neuro imaging is concerned the treating physician, radiologist should be aware of these conditions which are common during pregnancy. Even the MRI technician should be trained for this to do necessary changes in a given study depending upon the findings while doing MRI like running Angio or Veno sequence as and when required.