Wednesday, September 28, 2011

Supraspinatus avulsion tear - MRI

Proton density oblique coronal MR image in 41 year old male patient with trauma showing focal fracture in the greater tuberosity of the humerus (arrow head) with full thickness tear in the supraspinatus tendon and retraction of the tendon fibers (arrow) suggestive of full thickness avulsion tear.

T1 TSE oblique coronal MR image showing focal fracture in the greater tuberosity of the humerus (arrow head) with absent hypointense  supraspinatus tendon.

Axial T2 Medic (GRE) image showing fracture and tendon tear.

Sagittal STIR image showing full thickness tear and absent tendon fibers.

Discussion:
  • Full-thickness avulsion tears of the tendon away from the greater tuberosity are less common.
  • Massive tears often extend posteriorly to involve the infraspinatus tendon or extend anterior to tear, the anterior interval and subscapularis tendon.
  • If an acute complete supraspinatus tendon tear is identified, surgery is often scheduled within the next several days so that the tendon can be repaired before the development of retraction or atrophy.
  • Angled oblique sagittal T2/STIR images perpendicular to the plane of the supraspinatus tendon can better delineate the partial and full thickness tears.

Tuesday, September 27, 2011

Calvarial thickening - MRI

T1 weighted axial image in 24 year old female with thalasemia showing diffuse thickening of the calvarium.

T2 weighted axial image showing calvarial thickening.

FLAIR axial image showing calvarial thickening.

Discussion:
Differential diagnosis of calvarial thickening:
  1. Various severe anemias - bone marrow expansion.
  2. Pagets disease.
  3. Hyperparathyroidism.
  4. Osteopetrosis.
  5. Chronic Dilatin therapy.
  6. Acromegaly.
  7. Some rare genetic diseases - Camurati-Engelmann’s disease, frontometaphyseal dysplasia and   craniodiaphysial dysplasia.

Traumatic optic nerve compression - CT

Axial CT section through the optic nerves in a 59 year old male with trauma showing fracture in the posterior part of the lateral wall of the right orbit and the fracture fragment is causing compression on the optic nerve at the optic canal (arrow) and note the normal wide optic canal on left side (arrow head).

Coronal CT scan bone window showing the bony fragment compressing the optic nerve and narrowing the optic foramen (arrow) and note the normal foramen on left side (arrow head).

Sagittal image showing the bony fragment compressing on the optic nerve.
Discussion:
  • Traumatic optic neuropathy is a devastating potential complication of closed head injury.
  • The hallmark of an optic neuropathy, traumatic or otherwise, is a loss of visual function, which can manifest by subnormal visual acuity, visual field loss, or color vision dysfunction.
  • Vision loss associated with traumatic optic neuropathy can be partial or complete and temporary or permanent.
  • Best diagnostic test is Thin-slice CT scan of the nose, sinuses, and orbits
  • Fractures through the optic canal can be best depicted with thin-section CT scanning (eg, 1.5-mm cuts with 1-mm intervals).
  • CT scanning provides adequate imaging of orbital soft tissue and is better than MRI at delineating bony defects. 
  • It provides an intraoperative road map for the surgeon in patients who require surgical decompression and can be used for image guided endoscopic surgery.
  • Treatment is observation, steroids and optic nerve decompression. The decision for surgical decompression should still be based primarily on the clinical examination findings.

Cystosarcoma phyllodes tumor

Film screen mammogram of the right breast in 41 year old female showing large well defined dense lesion with smooth margins. No calcification. 


USG of the same patient showing heteroechoic mass lesion with well defined smooth margins. The lesion shows width>breadth. No evidence of calcification.

Discussion:
Cystosarcoma phylloides is a rare breast tumor that accounts for approximately 0.5% of breast tumors examined at biopsy and approximately 2.5% of-fibroid epithelial tumors examined at biopsy. This tumor was named in 1838 by Johannes Muller, who described large firm tumors of the breast. He believed the tumor to be benign and observed that the surface had a leaf-like (phylloide) configuration and contained narrow cyst-like spaces within a sarcoma- like stroma.

It was not until 1943 that Cooper and Ackerman reported on the malignant biological potential of this tumor. Clinically, patients present with a palpable breast mass. Although periods of rapid growth are known to occur, the mass usually develops slowly. The lesion is mobile, not fixed to the skin or the chest wall. Although the lesions have occasionally been noted in both breasts, they are usually found only in one. They have been reported to occur in patients of any age, although the average age is 40 to 45 years.

Mammogram usually shows well defined mass lesion of varying sizes, predominantly large mass. The lesion shows smooth margins in benign and irregular margins in malignant lesion. There may or may not have macrocalcification. USG shows solid mass lesion within the breast and shows a defined margins and some small fluid filled clefts with in the lesion may be diagnostic of cystosarcoma phylloides.

Sunday, September 11, 2011

Usual Interstitial Pneumonia with Tuberculosis - HRCT

Radiograph (scanogram)  of 81 year old male with dyspnea showing reticular opacities, fibrotic bands, honey coombing and few fibrocavitatory lesions in bilateral upper lobes consistent with UIP with old Tuberculosis.


HRCT of 81 Year old female showing macrocystic honeycombing and reticular
opacities predominantly in the subpleural region.

HRCT along the upper lobes showing fibrocavitatory lesions

Coronal lung window showing reticular shadows and honey combing predominantly in the basal region with fibrocavitatory lesion in upper lobes.

Usual Interstitial Pneumonia - HRCT

HRCT of 40 Year old female showing macrocystic honeycombing, reticular
opacities predominantly in the subpleural region, architectural distortion and
areas of focal ground-glass opacity 

Mediastinal window of the same patient showing small enlarged pre tracheal lymphnode.

Discussion:

Idiopathic Pulmonary Fibrosis (IPF) is the most common entity of the Idiopathic Interstitial Pneumonias (IIPs). By definition, IPF is the term for the clinical syndrome associated with the morphologic pattern of UIP.
Median survival - 2 to 4 years.

Clinical features - Presents in 50 years old or older. Patients present with progressively worsening
dyspnea and nonproductive cough.

Histopathologic Features: Spatial and temporal heterogeneity, architectural distortion and fibroblastic foci.

HRCT: Distribution is apicobasal gradient and predomonently subpleural location. 
Features are macrocystic honeycombing, reticular opacities, traction bronchiectasis, architectural distortion and focal ground-glass opacity.

Saturday, September 10, 2011

Temporal bone fracture with facial nerve injury - HRCT

HRCT of right temporal bone axial image showing transverse temporal bone fracture (arrow) and the fracture line passing through the first anterior genu of the facial nerve canal (arrow head).

Subsequent section of the HRCT right temporal bone showing the fracture passing through the facial nerve canal (arrow head).

Discussion: Temporal bone fractures classically are described with reference to the long axis of the petrous bone.
Classification:
1. Longitudinal (parallel to the axis).
2. Transverse (perpendicular to the axis).
3. Oblique/Mixed- Common.


Longitudinal fracture: The fracture line of force runs roughly from lateral to medial. A fracture line may extend through the facial nerve canal, thereby damaging the facial nerve. Associated injury, such as transection or intraneural hemorrhage, may cause facial nerve paralysis, as can damage from displaced bone fragments.


Transverse fracture: result from trauma to the occiput or cranial-cervical junction, with the line of force running roughly anterior to posterior.A fracture passing through the vestibulocochlear apparatus can cause sensorineural hearing loss and equilibrium disorders. Transverse fractures also commonly injure CN VII, because their path often takes them close to the nerve's labyrinthine segment.

Mixed fractures: Oblique (or mixed) fracture patterns, which extend both longitudinally and transversely, are common, and some case series report that these occur more often than do isolated transverse or longitudinal fractures.

Radiology:
Radiography: Plain film radiographs of the skull may show opacified mastoid air cells, intracranial air, or, rarely, a lucency (fracture line).

HRCT: can demonstrate a lucency through the temporal bone. Involvement of the middle ear, petrous bone, otic capsule, and facial nerve canal are the primary determinants of prognosis.


MRI: may demonstrate fluid (high signal on T2-weighted images) in the middle ear and mastoid air cells. T1-weighted images may reveal a bright signal in the labyrinth or middle ear, consistent with hemorrhage.

Splenic Artery Aneurysm in Extrahepatic Portal Vein Obstruction - CT Angio

Axial thick MIP image of CT angiography showing aneurysm arising from the main splenic artery

Coronal thick MIP image of CT angiography showing aneurysm arising from the main splenic artery

3 D volume rendering image of CT angiography showing aneurysm arising from the main splenic artery (arrow).

Axial CT image in venous phase showing multiple collateral veins in the porta with non visualised main portal vein consistent with extra heaptic portal vein obstruction. Note splenomegaly and multiple leinorenal collaterals.

Discussion:

Splenic artery aneurysms (SAA) are the most common visceral aneurysm occuring predominantly in females. SAA causing EHPVO and presenting with features of portal hypertension is extremely rare.
Women are affected four times more commonly by SAA and often during pregnancy and childbearing years due to endocrine changes.
The usual location of splenic artery aneurysm is at the mid or distal portion of the splenic artery, frequently found at the arterial bifurcation.

Clinical features: They are usually asymptomatic, and the symptomatic presentation includes chronic abdominal pain of varied severity or an acute rupture with hypotension.

Radiology:
CT angiography is the best modality for the diagnosis, although it is usually detected incidentally.

Treatment:
Endovascular: Coiling or covered stent.
Operative: Aneursyectomy with or without splenectomy.

Friday, September 9, 2011

Tracheal Foreign Body - CT Scan with 3D.

CT scan axial soft tissue window of 7 Months old male child with history of foreign body aspiration with asymptomatic baby showing linier metallic foreign body oriented vertically in the center with patent lumen on either side. 

Coronal reformatted CT scan soft tissue window well delineate the vertical extent of the foreign body

Minimum intensity projection (minIP) image showing the foreign body. 

3D Volume rendered image showing showing the foreign body. 

Virtual bronchoscopy showing showing the foreign body (arrow). 

Extraction by bronchoscopy is the treatment of choice for tracheal foreign bodies