Friday, August 31, 2007

Epidermoid Tumour Brain--MRI



On T1-weighted images epidermoids are generally slightly hyperintense or isointense relative to gray matter. The lesions are usually isointense relative to CSF on T2-weighted images, but they may be slightly hyperintense. Now, diffusion-weighted imaging can be used to differentiate these entities, because epidermoids have markedly restricted diffusion and, therefore, high signal intensity on the diffusion-weighted trace images. The free water in arachnoid cysts has low signal intensity.

Thursday, August 30, 2007

Chiari malformation-MRI



The cerebellar tonsils are elongated and pushed down through the opening of the base of the skull blocking the flow CSF. The brainstem, cranial nerves, and the lower portion of the cerebellum may be stretched or compressed.The blockage of CSF flow may also cause a syrinx to form, eventually leading to syringomyelia.

Tuesday, August 28, 2007

Spinal Cord Astrocytoma-MRI

Intramedullary Cord Tumours
Ependymoma-The most common intrinsic spinal cord tumor has a male predilection and a fourth-decade prevalence. They occur anywhere in the cord and are commonly in the conus medullaris, where an exophytic component may be present. They rarely change growth characteristics and metastasize. Lesions are characteristically hypovascular, well circumscribed, and noninfiltrative of the surrounding cord. Symptoms are due to compression of the surrounding cord rather than infiltration. Complete resection often results in prolonged survival.


Astrocytoma These lesions are more common in children than in adults. Sometimes they are associated with microcysts or syrinxes. The pilocytic varieties are well differentiated and tend to be indolent, with a definable surgical plane. Fortunately, anaplastic astrocytoma or glioblastoma are rare. Surgical therapy does not improve the dismal course, with death usually occurring within 2 years
Case by Teleradiology Providers

Details reading in Emedicine article

Friday, August 24, 2007

Radiology Grand Rounds-XV






Here is a case of An Unusual Pleural Tumour for the Radiology Grand Rounds submitted by Dr MGK Murthy of Teleradiology Providers. Concept of the Radiology Grand Rounds is available at- Radiology Grand Rounds.


An Unusual Pleural tumour. Dr Jaya, NMC Sky Imaging center, LLRM Medical College, Meerut, Dr(col) M G K Murthy,Dr Sumer Sethi.
Teleradiology Providers http://teleradproviders.com/



INTRODUCTION:


Many neoplastic tumors exhibit paraneoplastic syndromes manifested by endocrinopathy. This is particularly true of intrathoracic tumors such as lung cancers, thymomas, carcinoid tumors and mediastinal germ cell neoplasms. Solitary fibrous tumors (SFT) of the pleura are rare tumors with unpredictable clinical behavior. SFTs of the pleura previously reported as ‘localized benign mesotheliomas’ have been known to be associated with symptomatic hypoglycemia.1 Localized fibrous mesolitheliomas have been known by other names such as solitary mesotheliomas, submesothelial fibromas and pleural fibromas2; due to controversial nature of origin of the tumor. To evade the discussion about histogenesis, the name ‘solitary fibrous tumor’ is used 2,3.

CASE REPORT:
A 56-year normotensive, nonsmoker male presented with recurrent syncopal attacks, light-headedness and generalized weakness, usually upon awakening or about 4-5 hours after his last meal. He had no history of cough, breathlessness or chest pain. Clinical examination revealed grade 1 clubbing. Chest examination revealed dullness to percussion with decreased breath sounds over the lower half of right hemithorax. Post Prandial Blood sugar level was 75 mg %, C-peptide level was 0.71 mg%; serum insulin level was 4.11mIU/ml (normal fasting level 5-20mIU/ml). Chest X-ray showed a large homogeneous opacity occupying the mid and lower zones of right hemithorax. Right lower lobe showed evidence of collapse and rest of the lungfields didi not show any abnormality. Ultrasound examination showed a well defined rounded mixed echogenic mass in the lower half of right hemithorax above the dome of right hemidiaphragm with minimal right pleural effusion. Subsequent CT examination revealed a large mildly enhancing right pleural mass of solid consistencey with a few areas of hypodense nonenhancing regions suggestive of necrosis. CT value ranged from 20 to 60 HU. No evidence of ribdestruction/brochus cutoff or any mediastinal lymphadenopathy demonstrated. No calcification was seen. Minimal pleural effusion was suggested. Lower lobe all segments showed evidence of collapse. Rest of the lung fields showed no significant abnormality. Radiologically a primary pleural based neoplasm was suggested possibly mesothelioma. FNAC was inconclusive. Metastatic workup showed no abnormality.
Right posterolateral thoracotomy was performed. A large lobulated mass, occupying the posterior and inferior portions of the lower half of right hemithorax was present. The tumor was found to originate from the visceral pleura in the right supradiaphragmatic location. There were no attachments of the tumor to the lung, chest wall or diaphragm. The resected mass measured 19x12x11cm and weighed 4 kilograms. Cut section of the mass showed nodular pattern with large whorled white areas. Histopathological examination showed extensive collagen formation and spindle-like cells with rare mitosis. The spindle cells were arranged in single file pattern, ill defined fasicle with myxoid change and in “patternless pattern”. These findings were consistent with the diagnosis of solitary fibrous tumor of pleura. The postoperative course was uneventful. Blood sugar levels returned to normal after surgery.
DISCUSSION-
The First SFT was described by Wagner4 in his article “Das Tuberkelahnliche Lymphadenom.” In 1931, Klemperer and Rabin5 discovered a diffuse type of tumor that arose from the mesothelial layer from a localized form that arose from the submesothelial connective tissue. In 1952 Clagett et al6 used the term localized fibrous mesothelioma to distinguish these usually benign tumors from the more common asbestos related, malignant mesothelioma. Solitary fibrous tumors (SFTs) represent less than 5% of all neoplasms involving the pleura. SFTs are spindle cell neoplasms. They are usually benign, but may be malignant. In the thorax, they usually involve the pleura, but can be intrapulmonary or mediastinal. Histologically, they show a variety of arrangements, from a “patternless pattern” to a hemangiopericytoma-like or diffuse sclerosing appearance, and stain positive for CD34 and vimentin 7.
Most solitary fibrous pleural tumors cause minimal symptoms despite growth to huge proportions8. When present, the most common symptoms are cough, chest pain, dyspnea and pulmonary osteoarthropathy. Hypoglycemia is rare 9,10. Rarely fibrous pleural tumors are malignant and recur locally or at a metastatic site. Most neoplasms associated with hypoglycemia are pancreatic β-cell tumors. Doege11 reported the first patient with an intrathoracic fibrous tumor associated with hypoglycemia in 1930 (Doege Potter syndrome). In 1981, Briselli reviewed 360 cases of solitary pleural fibrous tumors reported since 1942. Four percent had symptomatic hypoglycemia12; one instance of hypoglycemic coma was fatal 13.
Several mechanisms for hypoglycemia associated with solitary fibrous tumors have been proposed; these include secretion of insulin-like growth factor II (IGF-II or big IGF-II), increased utilization of glucose by the huge tumor, insulin receptor proliferation mediated by the solitary fibrous tumor, decreased gluconeogenesis, and decrease ineffective glucagon secretion. Secretion of IGF by the tumor is the most widely accepted mechanism for hypoglycemia in fibrous masses14, 15. The finding of increased IGF-II with hypoglycemia before resection and decreased IGF-II with abatement of hypoglycemia after resection16, supports this hypothesis.
Our patient had hypoinsulinemic hypoglycemia. After resection the blood sugar and the insulin levels returned to normal. There is an overexpression of IGF II, which is responsible for hypoglycemia in solitary fibrous tumors 17.
In conclusion when confronted with a patient with hypoglycemia and suppressed insulin levels, non-islet cell hypoglycemia should be considered. The case reported here demonstrated that a solitary fibrous pleural tumor should be considered in the differential diagnosis. This case is reported in view of its extreme rarity.

Wednesday, August 22, 2007

Intraventricular Meningioma-MRI


An intraventricular location is relatively rare, accounting for only 2 % of meningiomas, with 80% of these in the lateral ventricles. Despite this, intraventricular meningioma is the most common trigonal mass in the adult. They are thought to form via the infolding of meningeal tissue during the formation of the choroid plexus. Nonenhanced CT typically demonstrates an iso- to hyperdense lesion. Calcification is seen in 20% of cases, with a psammomatous pattern (diffuse, sand-like appearance) most common. Circular, globular, or radial calcification may also be seen. On MRI, lesions are typically hypo- to isointense on T1-weighted images and iso- to hyperintense on T2-weighted images. Lesions classically show intense uniform enhancement on both CT and MR images after injection of contrast media due to their lack of blood-brain barrier.

Monday, August 20, 2007

Craniopharyngioma-MRI



Craniopharyngioma is a histologically benign, extra-axial, slow-growing tumor that predominately involves the sella and suprasellar space. Craniopharyngiomas are dysodontogenic epithelial tumors derived from the Rathke cleft, which is the embryonal precursor to the adenohypophysis. Changes in signal intensity vary on T1-weighted images depending on the cystic contents, which can appear hyperintense if they have a high protein, blood product, and/or cholesterol content.

Case By Dr MGK Murthy, Dr Sumer Sethi, Teleradiology Providers

Sunday, August 19, 2007

Patellar Osteomyelitis-A Rare Case Report




The patella is a rare site for acute osteomyelitis. Most cases are children between 5-15 years of age. The process of patellar ossification might explain this age predilection. The patella is a cartilaginous structure until 4 years of age. The ossification begins at 4 years of age and is complete by 16 years. The rarity of the patellar infection may be explained by the nature of its blood supply and anatomy. The rich blood supply, and absence of epiphyseal plate with its associated sluggish hemodynamics, makes hematogenous osteomyelitis of patella a rarity. Staphylococcus aureus remains the most common cause of osteomyelitis followed by Streptococcus pyogenes, Other rare causes of acute osteomyelitis of patella include Pseudomonas aeruginosa. Related article-- Int Pediatr. 2001;16(4):232-234.

Case by Dr MGK Murthy (Teleradiology Providers), Dr Nageswar Goud and Dr David Kiran


Saturday, August 18, 2007

Spinal Haemangioblastoma


Here is a case of Spinal haemangioblastoma submitted by Dr MGK Murthy, Sr Consultant Teleradiology Providers.

Upcoming Radiology Conference information

Sultan Qaboos University and Hospital, Muscat, Sultanate of OMAN are holding an international MRI conference in Feburary 2008 in Muscat,Oman. Kindly see website http://www.radconoman.googlepages.com/ for more information..Their guest faculty includes Prof Ann Osborn etc. Oman is just two hours by air from India.

Thursday, August 16, 2007

Double PCL sign


The double PCL sign is associated with bucket-handle tears of the medial meniscus that occur in the presence of an intact anterior cruciate ligament (ACL). A bucket-handle tear is a longitudinal tear of a meniscus that results in a displaced but attached meniscal fragment. The fragment may become displaced into the notch between the PCL and the medial tibial eminence in the midline, with the fragment orientated parallel to the PCL. The intact ACL serves as a barrier that prevents further lateral displacement of the meniscal fragment. The ACL is pivotal in the resulting alignment of the structures that are responsible for the depiction of the double PCL sign. Since ligaments and menisci demonstrate a hypointense signal with all pulse sequences, the displaced fragment will mimic a second PCL that is anterior and inferior to the true ligament, hence the name "double PCL sign" Discussion is from Radiology 2004;233:503-504. Marc A. Camacho, MD, MS. The Double Posterior Cruciate Ligament Sign.

Original case reported and submitted By Dr MGK Murthy, Dr Sumer Sethi of Teleradiology Providers


Tuesday, August 14, 2007

Japanese Encephalitis


"S kumar et al documented in Neuroradiology. 1997 Mar;39(3):180-4 the MRI features in seven patients with Japanese encephalitis. In all the patients MRI revealed bilateral thalamic lesions, haemorrhagic in five. Signal changes were present in the cerebrum in four patients, the midbrain and cerebellum in three each, the pons in two and the basal ganglia in one. The lesions were haemorrhagic in three of the four patients with lesions in the cortex, two of the three with lesions in the midbrain and cerebellum, but the pontine lesions were haemorrhagic in both patients. Spinal cord involvement was seen in one of the three patients who underwent MRI. Bilateral thalamic involvement, especially haemorrhagic, may be considered characteristic of Japanese encephalitis, especially in endemic areas."

Sunday, August 12, 2007

Hepatocellular Carcinoma-MRI Findings


Notes for residents---A patient of alcoholic disease with raised alfa foetoprotein (can be more than 1000 ng/ml in 50% cases) and FNAC postive HCC. Features include capsule formation, presence of fat, suppressed on out of phase GRE images, no definite portal venous or hepatic venous invasion, No MR demonstrable calcification or biliary dilatation.Color doppler showed plenty of vascularity with increased diastolic flow.More common in males (7 to 8 times) more in 30-60 yrs. Contrast study would show increased early arterial enhancement, No significant contrast on equilibrium stage or hepatobiliary phase (1 hour) because hepatocytes are unable to excrete gadolinium in to bile and show it. Another feature would be peripheral washout in portal venous pahse. Pseudocapsule can enhance in portal venous phase. Case submitted by Dr MGK Murthy Sr Consultant Teleradiology Providers

Friday, August 10, 2007

Osteochondroma-MRI Features


"Further Reading--Malignant transformation as the most worrisome complication occurs in approximately 1% of solitary and 5-25% of multiple osteochondromas. Magnetic resonance imaging is the most accurate method in measuring cartilage cap thickness, which represents an important criterion for differentiation of osteochondromas and exostotic (low-grade) chondrosarcomas. Cartilage cap thickness exceeding 2 cm in adults and 3 cm in children should raise the suspicion for malignant transformation."

Case submitted by Dr MGK Murthy (Teleradiology Providers), Dr Nageswar Goud, and Dr David

Herpes Encephalitis


Abnormal bilateral symmetrical increased signal on T2 from the temporal cortex. Image morphology is suggestive or herpes simplex encephalitis.

Thursday, August 09, 2007

Amebic Brain abscess-a rare case report


Histology suggestive of--

Necrotising inflammatory lesion
Trophozoites
Immunohistochemistry
mononuclear infilterate – polyclonal
Suggestive of Amoebic abscess




History:
•1838, Morehead – assoc. of liver and brain abscess
• 1904, Kartulis – demon. E. Histolytica in brain abscess
•1944, Craig – described amoebic brain abscess


•Primary amoebic meningoencephalitis(PAM)
–Acute amoebic meningoencephalitis (AAM)
–Granulomatous amoebic encephalitis (GAE)

Case submitted by Dr MGK Murthy Sr Consultant Teleradiology Providers

Monday, August 06, 2007

Spinal arteriovenous malformation


Here is a classical MR picture of Spinal AVM, again submitted by Dr MGK Murthy,
Sr Consultant, Teleradiology Providers, http://www.teleradproviders.com/



CSF Rhinorrhea-MRI appearance


Here is a MRI T2 weighted coronal image of a patient with CSF Leak through the cribiform plate. Case By Dr MGK Murthy. Sr Consultant Teleradiology Providers

Thursday, August 02, 2007

Clinicians get the critical imaging results late!!


"Referring clinicians failed to electronically acknowledge over one-third of abnormal imaging results in an outpatient setting, even when a computerized test result notification system designed to alert referring physicians was used, according to a paper from Texas. Providers were unaware of critical imaging results in 4% of cases as long as four weeks after reporting."

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