Nuclear magnetic resonance proton imaging of bone pathology.

Thirty-two patients with diversified pathology were examined with a supraconductive NMR imager using spin echo with different TR and TE to obtain T1 and T2 weighted images. They included 20 tumors (12 primary, eight metastasis), six osteomyelitis, three fractures, two osteonecrosis, and one diffuse metabolic (Gaucher) disease. In all cases except for the stress fractures, the bone pathology was clearly visualized in spite of the normal lack of signal from the compact cortical bone. Nuclear magnetic resonance (NMR) imaging proved to be at least as sensitive as radionuclide scintigraphy but much more accurate than all other imaging procedures including computed tomography (CT) and angiography to assess the extension of the lesions, especially in tumors extended to soft tissue. This is due both to easy acquisition of sagittal and coronal sections and to different patterns of pathologic modifications of T1 and T2 which are beginning to be defined. It is hoped that more experience in clinical use of these patterns will help to discriminate between tumor extension and soft-tissue edema. We conclude that while radionuclide scintigraphy will probably remain the most sensitive and easy to perform screening test for bone pathology, NMR imaging, among noninvasive diagnostic procedures, appears to be at least as specific as CT. In addition, where the extension of the lesions is concerned, NMR imaging is much more informative than CT. In pathology of the spine, the easy visualization of the spinal cord should decrease the need for myelography.

Magnetic resonance imaging of the temporo-mandibular joint and meniscus dislocation.

A preliminary study of the temporo-mandibular joint (TMJ) by magnetic resonance imaging (MRI) was performed. Ten asymptomatic volunteers with no clinical history of TMJ disorder and five patients with a recent history of trauma to the TMJ were examined using a special surface coil. The meniscus, which is only slightly brighter than the surrounding tissue, gave a high signal and was demonstrated very clearly in its normal position in the controls and shown to be dislocated in the post-trauma cases. Four criteria for identification of the temporo-mandibular meniscus were established in the normal cases and compared with the findings in the pathological cases.

Magnetic resonance imaging (MRI) in patients with complex partial seizures and normal computerized tomography (CT) scan.

Magnetic resonance imaging (MRI) examination was performed in 18 patients with complex partial seizures (CPS) of long duration, who had normal computerized tomographic (CT) scans of the brain. Small MRI abnormalities correlating with the location of the epileptogenic focus in the EEG were demonstrated in 4 cases. The findings with strong signals were better demonstrated in the coronal view with longer time to echo (TE). In one patient, a lower signal lesion was documented, which was better visualized in the axial view with shorter TE. Patients with CPS should be subjected to MRI examinations with coronal and sagittal planes, using short and long TE in each slice. This method minimizes the chance for missing pathology.

Magnetic resonance imaging in orthopaedic surgery. A glimpse into the future.

Magnetic resonance images (MRI) were obtained of 10 healthy volunteers and 70 patients suffering from various orthopaedic disorders. Selected images of soft tissue, joint, bone and spinal abnormalities are presented and their interpretation is described. Although we have been using MRI for only a very short time, it is already possible to see its advantages: it provides good images of soft-tissues, detailed pictures of bone marrow, and excellent visualisation of the spine and spinal cord. The decision-making process in surgical procedures will in the future be influenced by this technique.

Magnetic resonance imaging of the pituitary gland.

Magnetic resonance imaging (MRI) was performed on 22 patients with a wide spectrum of pituitary disease and on 17 control subjects, in order to determine whether MRI is useful in localising and determining the extent of involvement of large and small pituitary tumours. The results indicate that MRI, with an 0.5 T superconducting magnet (Elscint, Israel), can be used to visualise large pituitary tumours and to determine the extent of parasellar and suprasellar involvement. The 'empty sella' syndrome can also be easily and confidently diagnosed. Some microadenomas can be visualised despite the relatively thick slices (0.7 cm) used in this study. These findings suggest that MRI in its current state of development is very useful in evaluating large pituitary lesions. With further technical refinements, improving the spatial resolution and decreasing slice thickness, this technique may come to be of some importance in the evaluation of pituitary microadenomas.

MRI parameters in multiple sclerosis patients.

Magnetic resonance imaging (MRI) findings of 20 patients with clinically definite multiple sclerosis (MS) are presented. The studies were performed on a 0.5 Tesla magnet using spin-echo technique. Analysis of the MRI findings included detailed linear measurements of the ventricular and the subarachnoid spaces and reading of the intensity of the grey and white matter and intensity of the MS plaques. The plaques were sorted according to their number and size. The younger patients (20-40 years) had overall more plaques than the older ones (over 40 years). The small plaques were the most numerous and the large ones were the least common. Statistically significant association was found between the number of plaques and the cella media width. The intensity ratios between the non-plaque white matter/grey matter showed a significant correlation with the ventricular score. A significant negative correlation was found between the antero-posterior diameter of the spinal cord and the number of MS plaques in the brain. The plaque/white matter ratio had a significantly negative correlation with the cervical cord's width.

MRI and CT scan compared with microscopic histopathology in osteogenic sarcoma of the proximal tibia.

The authors report the case of a 15-year-old female who presented with a history of vague but constant pain about the medial aspect of her right knee. X-ray established the presence of an expanding lesion in the medial tibial plateau. Computerized axial tomography (CT) and magnetic resonance imaging (MRI) were used in the evaluation of the lesion. The authors compare the preoperative CT and MRI findings with the microscopic histopathology of the amputation specimen and note that the CT scan underestimated the extent of the microscopic tumor boundaries, whereas MRI showed altered activity beyond these boundaries.

Gaucher disease: assessment with MR imaging.

The skeletal system, spleen, and liver of five patients with proved Gaucher disease were studied with magnetic resonance (MR) imaging. Homogeneous, low intensity signals resulting from relaxation times different than normal (longer T1 and shorter T2 values) were found in the marrow of long bones, vertebrae, and hips in all patients. In three patients, normal signals were noted in the patella, epiphysis of the knee, and capital femoral epiphysis. In two patients with acute bone pain in the tibial region, a higher signal was received from the tibial marrow. This signal was related to increased accumulation of fluid following an avascular episode. Soft tissues in the same area were also involved. Liver and spleen enlargement was readily visible, especially on coronal images. T1 values of spleen were significantly shorter than normal. MR imaging provides an excellent assessment of the extent of involvement of the liver, spleen, and bone marrow in Gaucher disease.