RADIOLOGICAL
CASES
SEPTEMBER 2013
PRESENTED BY:
DR. PATRICK A. CHUI WAN CHEONG Jr. OSK
DMRD FRCR
CASE 1
• 38 year old female with sudden onset of altered
consciousness, neurological deficit and headache.
DIAGNOSIS?
TUBERCULOSIS
CNS manifestation of TB
• TB incidence was in decline but has risen since 1986.
• AIDS epidemic – 30 % of TB patients are HIV positive.
Aetiology:
Mycobacterium Tuberculosis.
Other types eg Avium rarely affects the CNS.
CNS involvement :
 2 – 5% of all patients with TB.
 10% of patient with AIDS related TB.
Manifestations:
i.
Tuberculous granulomas (tuberculomas) - brain and spinal cord.
ii.
TB abscess.
iii.
Meningitis.
iv.
Epidural abscess from osteomyelitis or spondylodiscitis.
Pathophysiology:
 Hematogenous spread from a pulmonary source
– Grey white matter junction to form a granuloma.
 Abscess formation rare but more common in immunocompromised patients.
 TB meningitis can occur when
i.
A subependymal or subpial focus ruptures into the CSF.
ii.
Direct penetration of the walls of the meningeal vessels by hematogenous
spread.
Clinical presentation:
 Meningitis : Headache / Malaise / Low grade fever.
 Late complications : Neuropathy and hydrocephalus.
 Tuberculomas: Focal neurological deficits and seizures.
 CSF examination often shows striking low glucose levels in TB meningitis.
Imaging findings:
Tuberculoma – 4 Stages
i.
Cerebritis stage: Non-specific oedema. Ill-defined enhancement.
ii.
Solid granulomatous stage : Enhancing nodules +/- perilesional oedema.
iii.
Central caseation stage : Central hypointensity on MR T2 WI.
iv.
Involution stage: Shows calcified nodules on CT.
Cerebritis
Caseating tuberculoma.  Axial T2W MR image(a) of brain shows profoundly hypointense lesion in left frontal
lobe(black arrow) with marked perilesional oedema.
 The lesion demonstrates isointense core with slight hyperintense rim on T1W image(b),
and thin peripheral ring enhancement on gadolinium‐enhanced image(c).
 Note similar lesion in left occipito‐parietal region(white arrow).
Tuberculous abscess
 Usually larger than a tuberculoma – multiloculated – more perilesional
oedema.
 May be undistinguishable from a typical bacterial abscess.
Tubercular abscess in the right basal ganglia.
 A well‐defined hyperintense lesion is seen with a hypointense wall on axial T2‐weighted image (A).  Lesion shows ring enhancement on post‐contrast T1‐weighted image (B).
 On axial T2‐weighted sequence, it has central hyperintense signal corresponding to the pus cavity and the characteristic surrounding T2 hypointense signal of the abscess capsule (white arrow).  Local mass effect results in entrapment of the adjacent mildly dilated right temporal horn.
 Axial T1 postcontrast sequence demonstrates typical smooth ring enhancement of a mature abscess
TB meningitis:
i.
Typically causes a thick basilar exudate associated with meningeal
enhancement.
ii.
Communicating hydrocephalus and
iii.
Infarctions in the territories of the perforator vessels.
WIDESPREAD GYRIFORM ENHANCEMENT
Differential diagnosis:
 Infection – Viral, Bacterial, Tuberculous.
 Neoplasm – Primary or Secondary - more perilesional oedema.
 Sarcoidosis (rare).
Focal gyriform enhancement – AVM, Infarction, Encephalitis, Glioma. Treatment for TB
 Multidrug treatment regime.
 Serial imaging is useful to assess response to therapy.
Prognosis:
Mortality up to 30 % in non HIV and up to 80% in HIV +
CASE 2
16 year old girl with minor trauma to the elbow. DIAGNOSIS ?
OSTEOPOIKILOSIS
OSTEOPOIKILOSIS
 Sclerosing bony dysplasia with multiple enostoses.
 Rare inherited benign condition.
 Found incidentally on skeletal x rays.
 Correct diagnosis important.
 Not to be mistaken for pathology.
OSTEOPOIKILOSIS
Epidemiology
 The bone islands develop during childhood.
 They do not regress and hence seen in all age groups.
 No gender predilection.
 Autosomal dominant disorder.
OSTEOPOIKILOSIS
Clinical presentation
 Asymptomatic / Incidental finding.
 No malignant change.
 Bone strength is normal.
RADIOGRAPHIC FEATURES
Plain film and CT
 The bone islands of osteopoikilosis are typically clustered around joints
and align themselves parallel to surrounding trabeculae (thus
predominantly longitudinally in the metaphyses).
 Most lesions are found in the appendicular skeleton and pelvis.
 The axial skeleton is largely spared.
 The lesions vary in size, usually a 5 - 10mm, but ranging from only 1 2mm up to 1 - 2cm.
MRI
 Appearances on MRI are the same as individual bone islands.
 Each lesion is small and dark on both T1 and T2 weighted
images, as it is composed of mature dense bone.
Bone scintigraphy
 Bone scan should not demonstrate any increase in uptake.
 Useful if metastatic disease is considered in the differential.
 Osteopoikilosis is one of the skeletal "DON’T TOUCH” lesions.
Differential diagnosis:
 Appearances are characteristic.
 Few differentials.
When only a few lesions are seen on an isolated film, the differential
includes:
incidental bone islands (enostoses)
other sclerosing bony dysplasias
sclerotic metastases
osteosarcoma
lymphoma
osteoid osteoma: only rarely multiple
chronic multifocal sclerosing osteomyelitis
CASE 3
• 14 year old boy with progressive paraparesis and
gradual decline in intellectual function.
ADRENOLEUKODYSTROPHY
SPECTRUM OF
WHITE MATTER DISEASES
(LEUKODYSTROPHIES)
 Caused by pathology of myelin and/or oligodendrocyte.
 Either
inherited
(demyelination).
(dysmyelination)
or
acquired
WHITE MATTER DISEASES
 Dysmyelination
- Formation of intrinsically abnormal myelin, resulting in poor myelination
or early myelin degeneration.
 Demyelination
- Destruction of normal myelin with relative axonal preservation.
ACQUIRED LEUKODYSTROPHIES INFLAMMATORY
Multiple sclerosis and variants
Acute disseminated encephalomyelitis (ADEM)
Acute hemorrhagic encephalomyelitis
INFECTIONS
Progressive Multifocal Leukoencephalopathy (PML)
Lyme disease ‐ tick borne disease
AIDS encephalopathy
Creutzfeldt‐Jakob disease
METABOLIC
Central pontine myelinolysis
Malnutrition
Vitamin B12 deficiency
VASCULAR
Ageing changes affecting the white matter
Hypertensive encephalopathy
Hypoxic‐ischemic edema
TRAUMA
HEREDITARY LEUKODYSTROPHIES
LYSOSOMAL DISORDERS
Metachromatic leukodystrophy
Krabbe’s leukodystrophy
PEROXISOMAL DISORDERS
Adrenoleukodystrophy
Zellweger cerebrohepatorenal syndrome
Alpers’ disease
AMINO‐ACID AND ORGANIC ACID METABOLIC
DISORDERS
Canavan disease
Maple syrup urine disease
WHITE MATTER DISEASE OF UNKNOWN
METABOLIC DEFECT
Pelizaeus‐Merzbacher disease
Alexander’s disease
Congenital muscular dystrophy.
ADRENOLEUKODYSTROPHY
 Encompasses two genetic disorders causing varying degrees of
malfunction of the adrenal cortex and CNS myelin.
 Characterized by elevated levels of very long chain fatty acids.
 Uncommon and exclusively in males.
 Characterized by dysmyelination in the CNS.
 Hallmark is impaired Beta oxidation of the VLCFA’s.
ADRENOLEUKODYSTROPHY
Diagnosis:
 Typical clinical presentation.
 Presence of elevated blood levels of the VLCFA’s.
Aetiology
 Defect in a peroxisomal enzyme involved in the breakdown of the
VLCFA’s in the CNS, adrenal cortex and testes.
 Gene for this disorder has been mapped to Xq28.
ADRENOLEUKODYSTROPHY
Clinical findings:
 Typically presents between ages 5 to 10.
 Gait disturbances.
 Intellectual impairment.
 Adrenal insufficiency is present in 90% of cases.
 There may be a delayed presentation with onset of symptoms in
adolescence and adulthood – referred to as adrenomyeloneuropathy
(AMN).
 Adult type: Progressive paraparesis and sphincter disturbances and
66% have adrenal insufficiency.
MALE ALD
PHENOTYPE
DESCRIPTION
ONSET
RELATIVE
FREQUENCY
Childhood cerebral
Progressive
neurodegenerative
decline, leading to vegetative state
without treatment.
3-10 years
31-35 %
Adolescent
Similar to childhood cerebral, slower
onset
11-21
years
4-7 %
Adrenomyeloneuropathy
(AMN)
Progressive neuropathy,
Paraparesis, about 40 % progress to
cerebral involvement.
21-37
years
40-46 %
Adult cerebral
Dementia, behavioural disturbances
Adulthood
1-2 %
Asymptomatic
No clinical presentation.
Further studies may reveal
subclinical adrenal insufficiency.
Most common < 4 years
Addison Disease only
Adrenal insufficiency
<7.5 yrs
Up to 50 % in
childhood.
Varies with age.
ADRENOLEUKODYSTROPHY
Complications:
 Hypotonia
 Seizures
 Visual changes
 Dysphagia
 Deafness
 Progressive dementia
 Death occurs 1 to 10 years from onset of symptoms
ADRENOLEUKODYSTROPHY
CT
 low attenuation in the occipital white matter with involvement of the
splenium of the corpus callosum.
 +/- dystrophic calcification.
ADRENOLEUKODYSTROPHY
MRI
 Symmetric prolongation of T1 and T2 WI in the occipital white matter and
splenium.
 Involvement of the retrolenticular portion of the posterior limb of the
internal capsule is often contiguous.
 Involvement of the frontal white matter as disease progresses.
 T2 prolongation involving the corticospinal tracts in the pons and medulla.
 Auditory pathways involved.
 Post Gd – enhancement of the leading edge of active demyelination.
Inferior colliculus involvement
Lateral lemniscus
involvement
ADRENOLEUKODYSTROPHY
Treatment:
 Immunosuppression to modify the inflammatory response.
 Dietary therapy with specific fatty acids but is controversial.
 Bone marrow transplantation may arrest progression of disease.
 Adrenal hormone replacement therapy usually required.
Prognosis:
 Classic X-linked ALD – poor prognosis with relentless progression to
death.
 Adrenomyeloneuropathy has a much more favorable prognosis.
CASES 4
CAUSES OF PSOAS MUSCLE ABSCESSES
Primary cause:
As a result of hematogenous spread of an infectious process.
Primary psoas muscle abscess can occur in patients with:
Diabetes mellitus
IVDA
AIDS
renal failure
Immunosuppression
Secondary cause:
 Spread of infection from gastrointestinal disease
(e.g. appendicitis, diverticulitis, Crohn’s disease or perforated colon
carcinoma).
 Renal disease is the second most common source.
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