Dissection of Middle Cerebral Artery diagnosed by Magnetic Resonance Imaging

Arterial dissections usually arise from an intimal tear and can allow the development of an intramural hematoma. Dissection occurs frequently in the aorta or its branches and also occurs commonly in the internal carotid or vertebro-basilar arteries. The condition is rare in the intracranial cerebral arteries, especially above the supraclinoid segment of the internal carotid artery. The diagnosis of arterial dissection used to be made by conventional cerebral angiography. But recently, magnetic resonance imaging (MRI) is helpful to diagnose arterial dissection. We report two cases of middle cerebral arterial dissection using MRI.

CT Findings of Laryngeal Tuberculosis: Comparison with Laryngeal Carcinoma

PURPOSE: To determine the value of CT(Computerized Tomography) in the diagnosis of laryngeal tuberculosis and to assess to what extent its characteristic findings different from those of aryngeal carcinoma. Materials and Methods : CT scans of twelve patients with laryngeal tuberculosis were reviewed and compared with those of fifteen patients with laryngeal cancer, retrospectively. Clinical symptoms, laryngoscopic examinations and the presence of pulmonary tuberculosis on chest radiographs were also reviewed. RESULTS: In laryngeal tuberculosis, bilater alsymmetric or asymmetric involvement was noted in nine(75%) patients, while unilateral involvement was seen in three(25%). This was significantly different from laryngeal cancer in which unilateral involvement was noted in twelve patients(80%). Diffuse thickening of the free margin of the epiglottis was a characteristic and frquent finding in tuberculosis(n=6, 50%). No deep submucosal infiltration of preepiglottic and paralaryngeal fat spacesis seen in tuberculosis in spite of large areas of involvement of laryngeal mucosa, while twelve patients(80%) with laryngeal cancer showed thickened deep infiltration which resulted in a submucosal mass. CONCLUSION: CT was useful in the diagnosis of laryngeal tuberculosis and its CT findings wee characterized by bilateral involvement, thickening of the free margin of the epiglottis and good preservation of preepiglottic and paralaryngeal fatspaces in spite of large areas of involvement.

Intra-carotid thrombolytic therapy in acute ischemic stroke of carotid arterial territory

Intra-carotid urokinase (UK) infusion in 20 patients with acute internal carotid artery (ICA) territorial ischemic stroke achieved immediate recanalization in 45% and the clinical outcome in patients with recanalization was superior to that of patients without recanalization. The procedure was most effective in patients with smaller arterial occlusions: 7 of 10 patients with MCA branch occlusions (M2 to M4) achieved recanalization compared to only 2 of 10 with distal ICA or M1 occlusions, which should be an important issue for the critical evaluation of the efficacy of thrombolytic therapy (TT). Hemorrhagic transformation was observed in 9 patients on CT scan; petechial hemorrhage in 5 and intraparenchymal hematoma formation in 4. Among 4 patients with hematoma formation, clinical deterioration was seen in 3 cases and the angiography at the immediate end of the UK infusion showed recanalization in only one patient. The average dose of UK in patients with parenchymal hematoma formation was higher than that of patients without hemorrhagic transformation (123.3 x 10(4) units vs 101 x 10(4) units). The administration of a large dose of UK, probably more than 100 x 10(4) units, and the absence of immediate recanalization seemed to increase the risk of parenchymal hematoma formation. Despite the effort of investigators, the in-hospital time delay for the TT was significant which was mainly related to the time consuming preparation for angiography especially during night. A more effective system for the earlier intervention of acute ischemic stroke needs to be developed.

MRI of the internal derangement of temporomandibular joint: Comparison with arthrographic and operation

We retrospectively reviewed the MRI findings of 100 temporomandibular joints in 78 patients who had complained temporomandibular joint dysfunction. MRI findings were classified according to Wilke's staging criteria. And these findings were compared with arthrographic findings in 22 joints and surgical findings in 44 joints. According to Wilkes's staging. They were classified into 6 stages of abnormality: stage 0 (33 cases), stage I (19 cases), stage II (10 cases), stage III (18 cases), stage IV (6cases), stage V (14 cases). Among the 22 cases in which arthrography and MRI were done, both studies were well correlated in 10 joints. In 7 joints, MRI was superior to arthrography, which correctly demonstrated the meniscal displacement in 2 joints and . Meniscal deformity in 5 joints. In 5 joints, arthrography was superior to MR, which demonstrated the perforation (1 joint), adhesion (2 joint) and recapture of meniscus (2 joints). Compared with surgical findings, MRI correctly demonstrated the displacement of meniscus in all 44 joints. However, in case of the 10 meniscal perforation, MRI demonstrated the meniscal discontinuity in only 4 joints. Retrospective MR findings in 10 proven cases were the defect in posterior attachment in 4, far anterior meniscal displacement without recapture in 8m condylar spur in 4, and close bone to bone contact in 1. In conclusion, MRI as a primary Fiagnostic modality of temporomandibular joint derangment, is superior for the grading of displacement and deformity of meniscus but inferior for the evaluation of perforation, adhesion and recapture of meniscus to conventional arthrography. In case of the suspected meniscal perforation, arthrographic correlation is recommanded preoperatively.

Imaging diagnosis of venous malformation in head and neck

The venous malformation in head and neck is a developmental vascular disease which arises from the arrest in the certain stage of vascular embryogenesis. However, the lesion extends along the fascia and has a tendancy to recur after incomplete therapy. Retrospectively, the authors reviewed radiologic studies of 20 patients diagnosed as venous malformation during the last 5 years. The diagnosis was verified by histopathology (5 patients) and direct puncture angiography (15 patients). The radiologic studies included. CT with intravenous contrast injection (20 patients), RI angiography with 99m Tc-pyrophosphate (6 patients), and direct puncture angiography (15 patients). Multiplicity of venous malformation was noted in 9 patients. On CT scan, the lesions had lobulated irregular shape, with heterogeneous appearance, showed delayed enhancing characteristics, and had the phleboliths(21 lesions). The venous malformations were located at the masticator space (including masseter muscle) (n=12), retrobulbar space(n=6), submandibular space(n=4), paravertebral space(n=3) and so on. In two cases, the lesions were very extensive involving entire neck and parapharynx. On RI angiography using 99mTc-pyrophosphate, all of the lesions showed persistent and delayed uptake. With direct punture angiography the lesions could be classified as acinar pattern (n=17) and mixed pattern (acinar and saccular) (n=2). Venous connections were noted in 10 lesions. In conclusion, if a soft tissue mass on head and neck shows a heterogeneous attenuation density with or without calcified phlebolith on CT scan, RI angiography is recommended as a next diagnostic study. If it shows delayed persistent uptake, venous malformation can be suspected. Finally direct puncture angiography can verify the nature and extent of the lesions.