Diagnostic Accuracy of Low Tesla MR Imaging in the Internal Derangement of the Knee

PURPOSE: This study is for the evaluation of low tesla(0.064T) MR imaging diagnostic accuracy in the internal derangement of the knee. MATERIALS AND METHODS: We retrospectively analysed the MR images of 36 injured knees of 35 patients. The presence of tear was determined by arthroscopy or surgery in all cases. RESULTS: The sensitivity, specificity, accuracy, positive predictive value, negative predictive value of low tesla MRI for the diagnosis of anterior cruciate ligament injury were 83%, 88%, 86%, 77%, 91%, for the posterior cruciate ligament 75%, 95%, 86%, 92%, 83%, for the medial collateral ligament 83%, 96%, 92%, 91%, 92%, for the lateral collateral ligament 67%, 97%, 94%, 67%, 97%, for the menisci 75%, 93%, 89%, 75%, 93%. CONCLUSION: The low tesla MRI is an accurate method in detection and evaluation of the internal derangement of the knee.

CT and Fluoroscopy Guided Celiac Ganglion Block

PURPOSE: To evaluate the effects and usefulness of fiuroscopy guided celiac ganglion block after marking of needle path with CT scan. MATERIALS AND METHODS: Celiac ganglion block with 100% ethyl alcohol was performed in 50 cancer patients who were inoperable and had intractable abdominal pain. Duration and degree of pain relief after the procedure and its complication were analyzed. RESULTS: Early pain relief was observed in 98% and long term relief in 68% without serious complication. CONCLUSION: Fluoroscopy guided celiac ganglion block after marking of needle path with CT scan was a safe and valuable procedure in relieving intractable pain in terminal cancer patients and reduced the time in the CT room.

MR appearances of intracranial tumors with a low tesla (0.064 T) permanent MR system

In this report we describe twenty-two cases of intracranial tumors studied with an MR imager operating at a field strength of 0.064 T for evaluation of the clinical utility of low tesla MRI. The comfirmed diagnoses were meningioma(9 cases), astrocytoma(4 cases), glioblastoma multiforme(1 case), craniopharyngioma(2 cases), intracranial metastasis(1 case). pituitary microadenoma (1 case), hemangioblastoma (1 case), and trigerminal neurilemmoma(1 case). Meningiomas appeared as well-marginated, homogenous signal intensity masses(67%) in most cases. Most meningiomas showed iso-signal intensity(78%) on T1-weighted images, and high signal intensity on T2-weighted images. After Gd-DTPA enhancement, diffuse homogeneous contrast enhancement(75%) was well see. The multiple hemorrhagic foci within the glioblastoma multiforme were identified, which shoed high signal intensity on T1-weighted images and low signal intensity on T2-weighted images(intracellular methemoglobin), or high signal intensity on both T1 and T2-weighted images(extracellular methemoglobin). One case of cerebellar hemangioblastoma was a well-defined cystic mass with contrast enhanced mural nodule but no identification of characteristic signal void vessels. The remianing tumors showed low signal intensity on T1-weighted images, and high signal intensity on T2-weighted images. Gd-DTPA enhancement was helpful in separating the lesion from the surrounding edema or normal tissue, but had limited diagnostic value in characterizing the nature of the mass. The advantages of low tesla MRI are as follows on requirement of cooling water or electricity, open design, shorter T1 relaxation time compared with high tesla unit that increases the difference of T1-relaxation time between tissues, ease of installation, and cost effectiveness. In conclusion, the low tesla MRI is useful for the detection and evaluation of the brain tumors.