Post Spinal Anesthesia Intramedullary Injury

A young lady  2months after undergoing Caesarean section  complaints of both lower limbs weakness with non-specific distribution . In he history, during the  epidural anesthesia for caesarean, she experienced severe shooting pain in to the Right lower limb, which resolved with medication. MRI shows longitudinal  ill defined  cord signal abnormality possibly hydrosyrinx from D11 to conus with no bleed, expansion or arachnoiditis  or epidural collections. Submitted by Dr MGK Murthy and Mr Hari Om.

Epidural anaesthesia  is one of the safest procedures, but occasional complications are known. This case represents possibly

(i) inadvertent injection of local anesthetic  in to low lying   variant radiculomeduallry artery  branch, feeding the anterior spinal artery , leading to vascular injury

The other possibilities include

(ii) direct intradural administration of LA leading to chemical injury

(iii) direct long needle injury to the cord in high injection

(iv)hypotension injury to the cord during the procedure

(v) post infective sequelae (myelomalacia)

(vi)unusual epidural venous plexus injection leading to venous hypertension and infarction

(vii) unrelated to the procedure and incidental finding due to other  causes including trauma, Chiari malformation etc

Acute cerebellitis-MRI

Acute cerebellitis is one of the main causes of cerebellar dysfunction in children, and may be infectious, post-infectious or post-vaccination. Its aetiology is usually viral and a large number of viruses have been implicated (varicella-zoster, measles, mumps, coxsackie, Epstein-Barr, rubeola, pertussis and diphtheria, among others), although in most cases a definite aetiology remains undetermined . The cerebrospinal fluid examination may be normal or reveal pleocytosis, and the diagnosis is based mainly on clinical criteria . The disease is usually benign and self-limiting, its prognosis is habitually good, and recovery with a few or no sequelae is the usual outcome


IMAGING- It is usually bilateral,symetrical and MRI is the investigation of choice It displays predominantly graymatter and cortical signal abnormality with white matter involvement, which when it occurs is patchy and variable ,compressing the 4 th ventricle leading to obstructive proximal hydrocehalus. It is usually is low on T1 and bright on T2 and FLAIR with NO restricted diffusion(diff from acute infarction). Restricted diffusion is more common in bacterial and anerobic cerebellitis , though it can be seen in viral eiology Contrast enhancement is typically pial and along the sulcal spaces. MRS shows necrosis ,as lactate/ lipid in occassional cases

Differential diagnosis-- include acute intoxication by drugs, alcohol, tumours and demyelination (predominantly white matter involved). Lead poisoning could simulate this and so does Lhermitte-duclos (LDD)which could be differentiated by the presence of contrast enhancement and full recovery in cases of viral cerebellitis . If any surgical intervention is planned, in any caae resembling this disease ,it is worth repeating MRI after few weeks to see progress as viral cerebellitis will invariably improve.

Case by Dr MGK Murthy, Sr Consultant Radiologist.

Hypoxic ischemic encephalopathy-MRI

History : 4 day old neonate was delivered by LSCS after clinical fetal destress on account of meconium staining of the liquor. Apgar at birth reported normal with normal sugar levels presently, with history of seizures.MRI Brain shows two well defined dots of restricted diffusion seen in the parasagittal location of posterior parietal region predominantly involving the white matter, with not reaching upto the cortex, no significant basal ganglia or thalamic involvement, or cortical highlighting or diffuse white matter hyperintensity or gross structural abnormalities.

Hypoxic ischemic encephalopathy is now appropriatly reffered to as neonatal encephalopathy to encompase all the variants:

a) Commonest presentation for an acute hypoxia in term children usually leads to severe basal ganglia thalamic lesions ( BGT), predominantly an initially involving posterolateral lentiform nucleus and ventrolateral thalami. These are usually severe and lead to high mortality. The additional features amongst them diffuse cerebral edema, slit like ventricles and reduced extra-cerebral spaces.

b) The other uncommon variant is reffered to as parasagittal infarction which involves the deep white matter only at border zones of major arterial territories ( water shed ) some of these may present with full blown HIE as well. These occur usually in the presence of severe hypoglycemia and lead to microcephaly all though the neurodevelopmental outcome surprisingly good particularly for motor function because there is minimal or no involvement of BGT. These infants may also show more profound metabolic abnormalities such as prolonged conjugated hyperbilirubinemia, and recurrent hypoglysemia and developed marked cognitive and motor impairement.

c) Multifocal areas of infarction that do not appear to be in parasagittal distribution may be secondary to infections like herpes, varicella, and listeria, in which case contrast study would help. The CMV lesions may persist for years in white matter and not show atrophy, the key lies in the presence of subependymal cysts.

Case by Dr MGK Murthy, Sr Consultant Radiologist
Teleradiology Providers, Unit of Prime Telerad Providers (P) Ltd

Does the choice of MRI machine matter?

"This is about an article on Kevin MD  in which a patient underwent MRI cervical spine for neck pain and was reported normal. Imaging was substandard and physician wanted another repeat MRI. However, insurance company refused as MRI was just done a week back. Patient was admitted and repeat study revealed cervical herniated disk."

• My question in India in lot of places MRI are done in permanent magnet at about 0.3T strength and pathologies are often missed. Are they justified?
• As a Reporting Radiologist will you write on such reports suboptimal for reporting?
• What is the way out, for radiologists as if you are on payroll, you cannot possibly write suboptimal on each study and get paid for it as well. What if the patient sues the first radiologist for missed diagnosis, does he have the defense opf suboptimal machine and for that matter how do you define a suboptimal machine?

Basilar Artery Dissection-MRI

The MRI findings of dissection include an intramural hematoma, an intimal flap, and the enhancement of the artery wall and septum. MRA can clearly show abrupt luminal stenosis and the disappearance of flow signal at end distal to the dissection. This is 35 year old male with sudden onset posterior circulation infarct seen on DWI and intimal flap in the course images. Note the distal tapering in the basilar artery.

Lipomatous Filum terminale

Fat in the filum terminale is not an infrequent occurence, seen in 4 - 6% of individuals , and is especially easily detected on MRI. It is usually an incidental finding of no clinical concern.  There were no related symptoms and no evidence of tethering. The thickened fatty filum terminale seemed to be a developmental anomaly and without clinical significance.

Bilateral Thalamic Gliomas-MRI & MRS

Primary thalamic tumors are rare and bilateral thalamic tumors are even rarer. The incidence, clinical manifestations, natural history and prognosis of primary bilateral thalamic gliomas (PBTT) remain relatively obscure.  Spectroscopy reveals raised choline-creatinine ratio.

Reported by Teleradiology Providers

Normal Pressure Hydrocephalus-MRI

1. Ventricular enlargement out of proportion to sulcal atrophy.
2. Prominent periventricular hyperintensity consistent with transependymal flow of CSF. 

3. Prominent flow void in the aqueduct and third ventricle, the so-called jet sign, (presents as a dark aqueduct and third ventricle on a T2-weighted image where remainder of CSF is bright)
4. Thinning and elevation of corpus callosum on sagittal images

Opinion by -Teleradiology Providers

CO Poisoining-MRI

Bilateral globus pallidus hyperintensity is characterstic of CO poisoning. In this case this was an obscure case clinically and diagnosis of suspected retrospectively after MRI was done.

Reported by- Teleradiology Providers.

Acute disseminated encephalomyelitis-MRI

MRI in ADEM demonstrates regions of high T2 signal, with surrounding oedema. Punctuate, ring or arc enhancement is often demonstrated along the leading edge of inflammation. The center of the lesion, although high on T2 and low on T1 does not have increased restriction on DWI (D/D abscess), nor however does it demonstrate absent signal on DWI as one would expect from a cyst. This is due to increase in extra cellular water in the region of demyelination. However, absence of enhancement does not exclude the diagnosis.
Second opinion by -Teleradiology Providers

Intraparenchymal Haemorrhage on MRI

Mnemonic       Stage                    T1                              T2
------------------------------------------------------------------------------------
It Be           Hyperacute           isointense (I)                  hyperintense (B)

IdDy           Acute                     iso to hypointense (I)      hypointense (D)

BiDdy         Early Subacute       hyperintense (B)              hypointense (D)

BaBy          Late Subacute        hyperintense (B)              hyperintense (B)

Doo Doo    Chronic                hypointense (D)              hypointense (D)
---------------------------------------------------------------------------------------

B12 Deficiency- Cord & Brain Involvement

There is associated white matter involvement along with posterior column involvement which is relatively less commonly reported in B12 deficiency. This is 51 year old male who is non alcoholic, with possibly dietary deficiency. Reported by- Teleradiology Providers

HEMORRHAGIC INTRACRANIAL SECONDARIES

The incidence of hemorrhage in metastatic neoplasms is highest in melanoma, hypernephroma, bronchogenic carcinoma, and choriocarcinoma. Other metastatic tumours that bleed are breast and thyroid metastasis. Of the primary intracranial neoplasms, hemorrhage occurs most frequently in relation to pituitary neoplasms. Other primary tumors that have been reported to bleed include glioblastoma multiforme, lower-grade gliomas, ependymomas, choroid plexus papillomas, sarcomas, and meningiomas.
Our patient is 55 yr old male and shows large ring enhancing, slightly hyperintense lesions in parietal and frontal region. Lesions are hyperintense on both T1 and T2 weighted images and show ring enhancement on contrast study. This appearance is very suggestive of secondaries from renal cell carcinoma.

Second Opinion by -Teleradiology Providers

SACROCOCCYGEAL TERATOMA

Sacrococcygeal teratoma is the most common tumour of the fetus and neonate, with a reported incidence of 1 in 35,000-40,000. This neoplasm is composed of tissues from all three germ layers. The extent of sacrococcygeal teratoma was classified according to the American Academy of Pediatrics.
Type 1 – Primarily external and has only a mimimal presacral component.
Type 2 – Primarily external but has a significant intrapelvic portion.
Type 3 – Partially external but is predominantly intrapelvic with abdominal extension.
Type 4 – Located entirely within the pelvis and abdomen.
Associated complications :
· Intrapelvic mass effect- bladder displacement, hydronephrosis, large tortuous ureters and urinary ascites.
· Dysplastic changes in kidney.
· Severe oligohydoamnios.
· Congenital hip dislocation.
On MRI the content of teratomas can be well assessed. They may be solid, cystic or mixed with areas of necrosis, haemorrhage, and calcification. Predominantly solid masses have a poorer prognosis than cystic avascular masses.

Case Submitted by Dr Sangeeta Aneja, MD, Associate Professor & Head, Department of Radiodiagnosis, L.L.R.M. Medical College, Meerut.

Cortical Dysplasia-MRI

Focal cortical dysplasia is a common cause of intractable epilepsy in children and is a frequent cause of epilepsy in adults. All forms of focal cortical dysplasia lead to disorganization of the normal structure of the cerebral cortex. This is a 9year old girl presented with refractory complex partial seizures.

ADRENOLEUKODYSTROPHY-MRI

X-linked recessive disorder which occurs due to deficiency of peroxisomal enzyme Acyl Coa Synthetase. It is a white matter demyelination involving occipital lobes and splenium in bilateral and symmetric pattern (demyelination moves from centre to periphery). Males between 3-10 yrs of age are affected. Auditory pathways are involved commonly with sparing of subcortical white matter. On NECT, large symmetric low density lesion are seen in peritrigonal parieti-occipital white matter. Enhancement is noted in advancing rim surrounded with peripheral nonenhancing edematous zone. Calcifications may be seen. On MRI, central necrotic zone appears low on T1, high on T2. Intermediate zone enhances following contrast administration. Peripheral zone appears hypointense on T1 and high on T2. In one study, published in AJNR Vol 18, Issue 1, medullary and pontine corticospinal tract involvement was present in eight out of ten patients with ALD. So, pontomedullary corticospinal tract involvement is a common finding in ALD and is unusual in other leukodystrophy. On diffusion weighted images, advancing rim of demyelination shows restricted diffusion and appears as bright signal which is very well documented in our case.

Rare Posterior Epidural Disk Sequestration-MRI

This is a 40 year old male with sudden onset paraparesis. Posterior and left lateral epidural lesion in the L2-L3 showing hypointense signal on T1 weighted image and hyperintense signal on T2 weighted image along with peripheral rim enhancement on post gadolinium images. This may suggest an extruded disc with left lateral and cranial migration along with posterior epidural sequestration, which is although rare but reported. Other possibility is an infective posterior epidural collection.
Disk sequestration can be defined as a herniated disk with perforation of the fibrous ring (or outermost annulus fibrosus) and posterior longitudinal ligament with migration of the disk fragment to the epidural space. The most common path of disk fragment migration is a posterior and posterolateral direction to the anterior epidural space, which is delimited by the attachment of the posterior longitudinal ligament and its associated “midline septum” and “lateral membranes.” Therefore, disk fragment migration usually occurs cranial, caudal, or lateral but seldom posterior to the anterior epidural space. Migration of a sequestrated disk fragment in this manner has been reported only rarely.

Second opinion by - Teleradiology Providers