The causes for pseudoachalasia include primary malignancy of esophagus or gastroesophageal junction, 53.9%, secondary malignancies such as metastasis from lung or breast, 14.9%, benign disorders like mesenchymal tumors, secondary amyloidosis and peripheral neuropathy, 12.6%, and as a postoperative complication following antireflux surgery, 11.9%. Other rare causes are neurological disorders like meningomyelocele, brain metastasis, infiltration by lymphoma and paraneoplastic syndromes associated with small cell carcinoma lung, bronchial carcinoids and pleural mesothelioma.
Tuesday, December 29, 2009
Sunday, December 27, 2009
Saturday, December 19, 2009
Two year old male boy presented with recurrent episodes of transient ischemic attacks since the age of 6 months following which he has delayed milestones. The boy also has seizures since one year. He was referred to MRI brain for further evaluation.
Figure a) T1weighted image at the level of basal ganglia show multiple tiny low intensity rounded areas seen in bilateral basal ganglia (arrows) which appear hyperintense on T2 weighted images suggestive of collateral vessels. c) Fluid attenuation inversion recovery (FLAIR) sequence showing atrophy involving bilateral frontal and left parietal cortical areas with chronic ischemic changes. d) Volume rendered 3D time of flight frontal projection cerebral angiography showing significant stenosis in the supraclinoid internal carotid arteries on both the sides with absent flow in the anterior and middle cerebral arteries and multiple collaterals in bilateral basal ganglia appearing as “puff of smoke” (moyamoya). Cause is unknown in this boy.
- Hoffman HJ. Moyamoya disease and syndrome. Clin Neurol Neurosurg1997; 99 Suppl 2 : S39-44
- Gosalakkal JA. Moyamoya disease: a review. Neurol India. 2002 Mar;50(1):6-10.
- Fujisawa I, Asato R, Nishimura K, Togashi K, Itoh K, Noma S, et al. Moyamoya disease: MR imaging. Radiology. 1987 Jul;164(1):103-5.
Sunday, November 29, 2009
Saturday, November 28, 2009
Figure 1 a) Radiograph frontal view showing homogenous opacity lesion in the right upper and mid zone with broad base towards mediastinum. The lesion is causing shift of mediastinum and trachea to the contralateral side and compressing the trachea just above the carina (arrow head). The lesion is extending above the clavicle (cervico-thoracic sign) and erosion of posterior end of third and fourth ribs (Long arrow). C) Contrast enhanced CT scan axial section mediastinal window showing heterogeneously enhancing mass lesion in the right posterior mediastinum extending to middle mediastinum causing compression of the trachea. The lesion is showing multiple small foci of calcification (black arrows in fig c).
Primary mediastinal neuroblastoma accounts for 14% of all neuroblastomas. Common location is posterior mediastinum, where they arise from paravertebral sympathetic chain. Patient commonly present with chest pain, cough and respiratory distress due to airway obstruction. Chest radiograph is the initial radiological investigation to be done in such patients. It demonstrates homogenous opacity mass in the mediastinum. If the tumor is large, there may be extrinsic compression and displacement of trachea and main bronchus with mediastinal shift (fig a-c). Rib erosion and asymmetrical widening of inercostal spaces may be seen on radiograph. Intraspinal extension may be seen as loss of vertebral height with widening of neural foramina on lateral radiograph. Approximately 50% of the lesions show calcification on radiograph.
CT scan is usually done to confirm the presence of lesion, and it also helps to define the location and extent of lesion, adjacent organ involvement, or vascular involvement. CT demonstrates calcification in up to 90%. The lesion characterization has become better with the advent of multiplanar image reconstructions in MDCT. However MR imaging is the investigation of choice for better characterization and demonstration of full extent of mass, extradural intraspinal extension and chest wall invasion. The advantages of MR over CT are its direct multiplanar imaging and better contrast resolution, which can allow differentiation of vascular from non vascular lesions without the aid of intravenous contrast agent. MR is very often used to evaluate tumor involving spine and spinal canal.
Radiograph is the initial investigation to be done in the mediastinal masses and one should be able to identify the lesion and arrive at differential diagnosis. CT scan and MRI are done to confirm the lesion, location, extent, adjacent organ involvement or vascular involvement and intraspinal extension.
Friday, November 20, 2009
Thursday, November 19, 2009
- Hydatid disease is a parasitic infection caused by larvae of Echinococcus granulosus, which is still endemic in many sheepraising countries.
- Hydatid cysts can be located in various tissues, although they are most common in the liver (50–70% of cases) and the lung (20–30% of cases) in humans.
- Cardiac involvement in hydatid disease is uncommon, constituting only 0.5–2% of all cases of hydatidosis.
- Heart involvement - LV – 60%, RV – 10%, pericardium – 7%, pulm Artery – 6%, left atrial appendage – 6%, and interventricular septum is rare – 4%.
- Cardiac involvement occurs by invasion of the myocardium - Through coronary circulation or pulmonary vein from rupture of pulm cysts in to vein.
Signs and Symptoms •No symptoms due to its latency and slow growing nature unless it is situated in critical site. •Signs and symptoms are extremely variable and directly related to location and size of the cysts. •Precordial pain is the most common symptom and is most often vague and does not resemble angina pectoris. •Sudden rupture of intracardiac cysts is a frightful complication and can cause acute pericarditis or tamponade, acute pulmonary hypertension by embolization of several scolices, systemic arterial embolization, and severe anaphylactic shock can be life thretening.
- Imaging - Echocardiography, CT, and MRI can show the cystic nature of the mass and its relation to the cardiac chambers •CT best shows wall calcification. •MRI depicts the exact anatomic location and nature of the internal and external structures and is the technique used for posttreatment follow-up.
- The appearance of a hydatid cyst on MRI is usually a characteristic oval lesion that is hypointense on T1-weighted images and hyperintense on T2-weighted images. •A typical finding on T2-weighted images is a hypointense peripheral ring, which represents the pericyst (a dense fibrous capsule from the reactive host tissue). •A variety of tumors in the heart and a congenital pericardial cyst must be considered in the differential diagnosis; however, the multivesicular nature of the cystic mass and membrane detachment indicate the true diagnosis.
- The cysts may be single or multiple, uni or multiloculated, and thin or thick walled. •More specific signs are •Cyst wall calcification. •Presence of daughter cysts and Membrane detachment.
- •Surgery remains the treatment of choice in the management of hydatid disease. •Although antihelminthic drugs have been used in the preoperative and postoperative periods since 1977, extirpation of the lesion under cardiopulmonary bypass is recommended.
- To conclude CT and MRI are helpful for localizing and defining the morphologic features of hydatid cysts. •Specific signs include calcification of the cyst wall, presence of daughter cysts, and membrane detachment. •CT best shows wall calcification, whereas MRI depicts the exact anatomic location and nature of the internal and external structures.
Wednesday, November 18, 2009
Tuesday, November 17, 2009
Sunday, November 8, 2009
MRI of 30 year old female T1 weighted image showing well defined slightly hypointense lesion with central hypointense scar which is showing slightly hyperintense on T2 WI. In venous phase the lesion is showing homogeneous contrast enhancement (arrow). In delayed phase image there is enhancement of scar.
CT of another 28 year old female showing well defined showing arterial enhanging lesion in the left lobe of liver with central non enhancing scar. On venous phase image the lesion shows homogeneous contrast enhancement. In delayed phase image there is enhancement of scar.
FNH is considered a non-neoplastic, hyperplastic response to a congenital vascular malformation. Histologically, FNH is not a tumor and consists of benign-appearing hepatocytes occurring in a liver that is otherwise normal (i.e. no cirrhosis).
On CT scan the FNH are hypervascular lesions with homogeneous enhancement in arterial phase and hypodense central scars in arterial and venous phase, which enhance in the equilibrium phase. This is characteristic of FNH.
On MR typical FNH is slightly hypointense on T1WI and slightly hyperintense on T2WI. The scar is somewhat hyperintense on T2. The enhancement is as we expect with 'capillary blush' with a scar that enhances late in the equilibrium phase. We need to differentiate fibrolammellar carcinoma (FLC) of liver from FNH as the imaging findings are almost similar except for few differentiating points. The central scar is hyperintense on T2 in FNH where as it is Hypo in FLC. Scar enhances in delayed phase of contrast study in FNH where as it will not enhances in FLC. May see calcification in FLC and not in FNH.
Monday, September 21, 2009
The primary sternal tumors are quite rare. The most commonly occurring malignant tumor in sternum is chondrosarcoma and occurrence of osteosarcoma in sternum is extremely rare. The most common tumors of sternum are the metastases of lung, renal or thyroidal malignancies. CT may show lytic, mixed or sclerotic pattern and it is observed as an expansile mass lesion with irregular borders, and the lesion invades bone marrow by destroying the cortex. MRI clearly demonstrates the extent of the lesion and characterization of the lesion.
Wednesday, September 9, 2009
Metallic foreign body in another patient in right orbit on radiograph (arrow). CT scan axial section of the same patient showing foreign body just posterior to the limbus which is extra occular.
Sunday, August 30, 2009
Tuesday, August 25, 2009
Tuesday, August 11, 2009
Sunday, August 9, 2009
Saturday, August 8, 2009
Thursday, August 6, 2009
Wednesday, August 5, 2009
Tuesday, August 4, 2009
Monday, August 3, 2009
CT scan of 44 year old male came with history of hematuria showing large intraluminal mass lesion arising form the left lateral wall of the urinary bladder. Biopsy proved to be adenocarcinoma bladder.
CT of another patient with hematuria showing large heterogeneously enhancing soft tissue mass lesion arising from the right lateral wall of urinary bladder. Biopsy proved to be carcinoma urinary bladder.
Bladder cancer is the second most common malignancy of the genitourinary system. Adenocarcinoma of bladder is rare tumors of bladder, accounts to 2%. Majority of tumors are transitional cell carcinomas (90%) and Squamous cell carcinoma (5%). Classic clinical presentation is painless, gross hematuria. Risk factors include smoking, pelvic irradiation, exposure to aniline dyes and chemotherapy with cyclophosphamide. Very often the newely diagnosed carcinoma will be superficial (72%). 5 % come with metastases to lymphnodes, liver, lung, bone and brain. CT and MRI are indicated mainly for staging of the tumor. Superficial bladder cancer has good prognosis with 5-year survival rates of 82-100%. Prognosis for metastatic transitional cell cancer is much poorer with only 5% of patients living 2 years after diagnosis.