BACKGROUND:In 1989, a group of sixty-seven asymptomatic individuals with no history of back pain underwent magnetic resonance imaging of the lumbar spine. Twenty-one subjects (31%) had an identifiable abnormality of a disc or of the spinal canal. In the current study, we investigated whether the findings on the scans of the lumbar spine that had been made in 1989 predicted the development of low-back pain in these asymptomatic subjects. METHODS:A questionnaire concerning the development and duration of low-back pain over a seven-year period was sent to the sixty-seven asymptomatic individuals from the 1989 study. A total of fifty subjects completed and returned the questionnaire. A repeat magnetic resonance scan was made for thirty-one of these subjects. Two neuroradiologists and one orthopaedic spine surgeon interpreted the original and repeat scans in a blinded fashion, independent of clinical information. At each disc level, any radiographic abnormality, including bulging or degeneration of the disc, was identified. Radiographic progression was defined as increasing severity of an abnormality at a specific disc level or the involvement of additional levels. RESULTS:Of the fifty subjects who returned the questionnaire, twenty-nine (58%) had no back pain. Low-back pain developed in twenty-one subjects during the seven-year study period. The 1989 scans of these subjects demonstrated normal findings in twelve, a herniated disc in five, stenosis in three, and moderate disc degeneration in one. Eight individuals had radiating leg pain; four of them had had normal findings on the original scans, two had had spinal stenosis, one had had a disc protrusion, and one had had a disc extrusion. In general, repeat magnetic resonance imaging scans revealed a greater frequency of disc herniation, bulging, degeneration, and spinal stenosis than did the original scans. CONCLUSIONS:The findings on magnetic resonance scans were not predictive of the development or duration of low-back pain. Individuals with the longest duration of low-back pain did not have the greatest degree of anatomical abnormality on the original, 1989 scans. Clinical correlation is essential to determine the importance of abnormalities on magnetic resonance images.

To show the frequent association of synovial cysts and facet effusion. MR studies of 26 patients with lumbar synovial cysts were reviewed for sex/age incidence, anatomic location, multiplicity of cysts and associated pathologies. All studies were reviewed for presence of facet effusion. 26 patients had 39 MRI documented synovial (17 females, 9 males). Age distribution: 41 – 79 years. Location of cysts: L4/5 = 29, L3/4 = 6, L5/S1 = 3, L1/2= −;1. 36 synovial cysts showed facet effusion. 19 patients also had facet effusions at adjoining motion segments or at contralateral joints. Synovial cysts were found in anterior (n=20), posterior (n=13), anterior-posterior (n=3) positions. 18 patients had cysts localized to one single facet joint, 8 patients showed synovial cysts at multiple facet joints. The frequent coexistence of synovial cysts and facet effusion in our material suggests a causal relationship. External herniation of synovium from a fluid expanded joint space appears to be the most plausible pathologic mechanism.

The orientation of the lumbar facet joints was studied with magnetic resonance imaging in 140 subjects to determine if there is an association between facet tropism and intervertebral disc disease or between the orientation of the facet joints and degenerative spondylolisthesis. The 140 subjects were divided into four groups: sixty-seven asymptomatic volunteers, forty-six of whom did not have a herniated disc on magnetic resonance scans (Group I) and twenty-one who did (Group II); forty-six symptomatic patients who had a herniated disc confirmed operatively (Group III); and twenty-seven patients who had degenerative spondylolisthesis at the interspace between the fourth and fifth lumbar vertebrae (Group IV). Axial scans were made at each lumbar level and digitized, and the facet joint angle was measured by two independent observers with use of image analysis software in a personal computer. The technique of measurement of the facet angles on magnetic resonance scans was validated with a subset of subjects who also had computed tomography scans made. Similar values were obtained with the two methods (r = 0.92; p = 0.00001). For the forty-six asymptomatic volunteers who did not have a herniated disc on the magnetic resonance scans (Group I), the median facet tropism was 5 to 6 degrees and was more than 10 degrees in 24 per cent (eleven) of the subjects. There was no association between increased facet tropism and disc degeneration. At the level of the fourth and fifth lumbar vertebrae, the median facet tropism was 10.3 degrees in the symptomatic patients who had a herniated disc at the same level and 5.4 degrees in the asymptomatic volunteers (Group I) (p = 0.05). The mean orientation of the lumbar facet angles relative to the coronal plane was more sagittal at all levels in the patients who had degenerative spondylolisthesis. The greatest difference was at the level of the fourth and fifth lumbar vertebrae (p = 0.000001). The mean facet angle was 41 degrees (95 per cent confidence interval, 37.6 to 44.6 degrees) in the asymptomatic volunteers and 60 degrees (95 per cent confidence interval, 52.7 to 67.1 degrees) in the patients who had degenerative spondylolisthesis. Furthermore, both the left and the right facet joints were more sagittally oriented in the patients who had degenerative spondylolisthesis. An individual in whom both facet-joint angles at the level of the fourth and fifth lumbar vertebrae were more than 45 degrees relative to the coronal plane was twenty-five times more likely to have degenerative spondylolisthesis (95 per cent confidence interval, seven to ninety-eight times). The increase in facet angles at levels other than that of the spondylolisthesis suggests that increased facet angles represent variations in anatomy rather than a secondary result of spondylolisthesis.

Our purpose was to evaluate the utility of functional MRI (fMRI) in the investigation of olfactory function. fMRI of the brain was performed on 12 healthy subjects and in 5 patients. Coronal sections were selected through the mid- to anterior temporal region of the brain. Significant activation was noted especially in the frontal and temporal lobes. Some of these activated regions corresponded to the orbitofrontal, entorhinal and pyriform cortical areas. Additional regions of activation were also observed in other areas of the frontal and temporal lobes. Imagination of smell produced less activation than active stimulation. Areas of negative activation were also noted in the frontal and temporal lobes. Patients demonstrated either abnormal patterns of activation, or no activation, depending on the nature of their dysfunction. These studies indicate that MRI may be used to demonstrate olfactory cortex activation.

The visualization of olfactory structures of the human brain during life has been difficult, if not impossible. While visualization of anatomical structures of the visual and auditory systems has been carried out for many years, olfactory structures have not been well defined. With the advent of MRI, it was possible not only to visualize these structures in patients with various disease processes, but also in subjects who did not have expressed abnormalities in olfactory functions. The purpose of this work is to estimate the success of the visualization of olfactory structures in a group of normal subjects and in patients. We also estimated the size of these structures in patients with loss of smell.

Autopsy findings are described of an atypical aneurysm of a large cerebral artery in a young child. The lesion is believed to have been an infective (mycotic) aneurysm. Antibiotics were administered at the time of the first leakage which had been thought to be due to a sinus infection. The sac wall exhibited a subacute pleomorphic inflammatory cell response indicative of a resolving infective aneurysm, and appearance that is likely to be encountered more often in the future.

The purpose of this study was to evaluate the feasibility of functional MRI (fMRI) in the investigation of transient global amnesia (TGA). MRI of the brain was performed on normal subjects and a patient with TGA. fMR images were obtained of left temporal and frontal regions of the brain. A 55-year-old woman was studied during a 6-h period of amnesia and again 2 weeks later, when memory had returned to normal. In all cases, memory testing was conducted during fMRI using a version of the Hopkins Verbal Learning Test. During TGA, the patient showed little or no activation during list learning or recognition testing. After her TGA had resolved, she demonstrated normal list learning and recognition. As in the healthy subjects, activation in the temporal region occurred during both list learning and recognition, whereas frontal activation was seen more often during recognition testing.

Georgetown University Hospital has been operating an image management and communications system (IMACS or PACS) for three-and-a-half years. This work was initially funded under the Army Medical Research and Development Command Digital Imaging Network Systems (DINS) project. The system was taken from a research system supporting only radiology tasks to one extended to clinical use, and has been used in clinical work for two-and-a-half years. This paper will summarize our PACS clinical experience and will describe the operational features implemented and those still necessary.

Echo planar imaging is a new MRI technique capable of producing images in short periods of time. This type of examination has the time resolution required to study the first passage of contrast medium through an organ. We report observations using this technique in 12 patients with regional variations in perfusion due to cerebral gliomas.

A complete image management and communications system has been installed at Georgetown University Hospital (GUH). The network is based on the A T & T CommView® System. In the Neuroradiology Division, this comprehensive network supports a multiscreen workstation with access to multiple imaging modalities such as CT and MRI from both the hospital and a remote imaging center. In addition, the radiologist can access these images from various workstations located throughout the hospital as well as from remote sites such as the home. Among the radiology services supported by the network, neuroradiology has the greatest need for such a system with extensive daily requirements involving the remote imaging center and on-line consultation around the clock. By providing neuroradiology with all available communication links, the radiologist can monitor, diagnose, and consult. The remote site has a subsystem capable of acquiring images and transmitting them over a high speed T1 data circuit. The GUH neuroradiologist can view these images on the neuro workstation or any of the workstations available in the Hospital. Fast and easy access to the images allows a radiologist to monitor multiple examinations as well as to utilize the workstation for diagnosis. To provide the neuroradiologist quick access to images at all times, a PC-based Results Viewing Station (RVS) has been placed in a doctor's home. Images may be sent to the RVS, or the user may request images from the central database at the hospital. Images can be viewed at home either as they are transmitted, or following transfer of a whole study. The efficiency and effectiveness of the system's capabilities with special regard to remote and teleradiology (RVS) operations have been studied for the neuroradiology service. This paper will discuss the current clinical acceptance and use, problems in implementation, and ways these difficulties are being surmounted.

A comprehensive image management and communication (IMAC) network has been installed at Georgetown University Hospital for an extensive clinical evaluation. The network is based on the AT&T CommView system and it includes interfaces to 12 imaging devices, 15 workstations (inside and outside of the radiology department), a teleradiology link to an imaging center, an optical jukebox and a number of advanced image display and processing systems such as Sun workstations, PIXAR, and PIXEL. Details of network configuration and its role in the evaluation project are discussed.

✓ A case is described in which incorrect preliminary programming of a computerized tomography (CT) machine caused transposition of the left- and right-side indicators in a CT scan, which led to craniotomy on the normal side. The possible mechanism for this is incorrect pre-scan programming of the CT scanner with respect to patient positioning in the scanner gantry. This error, although unlikely, is still possible with the present generation of CT scanners.