The MRI appearances of early vertebral osteomyelitis and discitis.

AIM: To describe the magnetic resonance imaging (MRI) appearances in patients with a clinical history suggestive of vertebral osteomyelitis and discitis who underwent MRI very early in their clinical course. MATERIALS AND METHODS: A retrospective review of the database of spinal infections from a spinal microbiological liaison team was performed over a 2 year period to identify cases with clinical features suggestive of spinal infection and an MRI that did not show features typical of vertebral osteomyelitis and discitis. All patients had positive microbiology and a follow up MRI showing typical features of spinal infection. RESULTS: In four cases the features typical of spinal infection were not evident at the initial MRI. In three cases there was very subtle endplate oedema associated with disc degeneration, which was interpreted as Modic type I degenerative endplate change. Intravenous antibiotic therapy was continued prior to repeat MRI examinations. The mean time to the repeat examination was 17 days with a range of 8-22 days. The second examinations clearly demonstrated vertebral osteomyelitis and discitis. CONCLUSION: Although MRI is the imaging method of choice for vertebral osteomyelitis and discitis in the early stages, it may show subtle, non-specific endplate subchondral changes; a repeat examination may be required to show the typical features.

MRI of lumbar spondylosis: a comparison of sagittal T2 weighted and three sequence examinations.

The aim of this study was to determine whether a single T2 weighted sagittal sequence could replace the conventional three sequence examination of the lumbar spine. The T2 weighted sagittal image of 79 lumbar spine MRI examinations were retrospectively reported by three radiologists. Features relating to degenerative disease were recorded and an assessment made of whether further sequences were likely to add information. On a separate occasion the T1 weighted and T2 weighted sagittal and T2 weighted axial sequences were reported blind in relation to the initial assessment. Areas of disagreement were resolved by consensus opinion. The T2 weighted sequence was compared with the three sequences, taking the three sequence examination as the standard. Disc protrusions were diagnosed from the T2 weighted sagittal images with a sensitivity of 38% and a specificity of 97%. 22 discs reported as a disc bulge on the T2 weighted sequence were re-classified as a disc protrusion on axial images because of their focal nature. Central canal stenosis was diagnosed on the T2 weighted sagittal sequence with a sensitivity of 60% and a specificity of 95%. After assessing the T2 weighted sequence, it was thought unlikely that further sequences would add extra information in 60% of cases (48/79). However, further information was obtained in 21% of these cases (10/48) when all the sequences were assessed. The extra information gained by using all three sequences was considered to be of greater benefit than the time saved by using a single T2 sagittal sequence. Other diagnoses where the additional sequences proved helpful are discussed.

The clinical significance of the high-intensity zone on lumbar spine magnetic resonance imaging.

STUDY DESIGN: Prospective observational study of anular tears, diagnosed by a high-intensity zone within the anulus on lumbar spine magnetic resonance imaging, and correlation with the clinical features. OBJECTIVES: To assess the prevalence of high-intensity zones in patients who are investigated for back and leg pain and to determine whether there are clinical features that can be used for diagnosis of the presence of a high-intensity zone. SUMMARY OF BACKGROUND DATA: Results in previous studies have shown that the presence of a high-intensity zone is associated with reproduction of a patient's pain on stress discography. Neural compression on magnetic resonance imaging has been shown to be associated with back pain, but to date, no study has correlated the presence of a high-intensity zone with the clinical features. METHODS: The lumbar spine magnetic resonance images in 156 patients in whom back and leg pain were investigated were analyzed for the presence and appearances of high-intensity zones. The clinical features of those patients with a high-intensity zone but with no evidence of neural compression on magnetic resonance imaging were analyzed by t test and X2 test. RESULTS: A high-intensity zone occurred in patients at a prevalence of 45.5% and usually occurred posteriorly (77%) and posterolaterally (22%) within the anulus. There were no features within the history, functional disability questionnaire, or physical examination that aided in a clinical diagnosis of those patients with a high-intensity zone. CONCLUSIONS: A high-intensity zone is a common finding in patients in whom low back and leg pain are investigated, but the presence of a high-intensity zone does not define a group of patients with particular clinical features.

Pain drawings in the assessment of nerve root compression: a comparative study with lumbar spine magnetic resonance imaging.

STUDY DESIGN: Prospective comparative study of pain drawings with findings on lumbar spine magnetic resonance imaging. OBJECTIVES: To assess the ability of the pain drawing to predict the presence of nerve root compression. SUMMARY OF BACKGROUND DATA: Most research work has concentrated on the ability of the pain drawing to act as a screening method for psychological distress with less work directed at the influence the anatomic abnormality has on the pain drawing. METHODS: One hundred thirty-four consecutive outpatients attending for lumbar magnetic resonance imaging in the investigation of back and leg pain completed pain drawings and psychological testing immediately before the examination. The pain drawing was analyzed by previously reported criteria, and the magnetic resonance imaging was assessed independently for the presence of nerve compression by three radiologists. Multivariate stepwise discriminant analysis was used to identify patients with nerve compression on the basis of their pain drawing. RESULTS: Nerve compression was predicted by numbness in the anterolateral aspect of the foot. There was considerable overlap in the appearances of the pain drawings between patients with and without nerve compression, and the pain drawing correctly classified only 58% of patients with nerve compression. CONCLUSIONS: The pain drawing is not a good predictor of nerve compression on magnetic resonance imaging in a group of patients investigated for back and leg pain. It should be interpreted with caution and in light of the full clinical picture.

Chronic low back pain in traumatic lower limb amputees.

OBJECTIVE: To ascertain the prevalence of back pain amongst traumatic lower limb amputees attending a regional rehabilitation centre and to determine the possible causes of back pain. DESIGN: All traumatic lower limb amputees given a semi-structured questionnaire to complete and a comparative subgroup of amputees with back pain and without back pain underwent physical examination, gait analysis, magnetic resonance scanning (MRI) and gait/standing stability analysis. SETTING: A subregional amputee rehabilitation centre. RESULTS: Transfemoral amputees were more likely to suffer from back pain (81 %) than transtibial amputees (62%) (p<0.05) and of those suffering from severe back pain, 89% and 81% also suffered from severe pain in the phantom limb and severe stump pain respectively. In two comparative subgroups of amputees there was no significant difference between back pain and pain-free groups except those with pain were more likely to have a body mass index (BMI) ratio above 50% of the recommended ratio. No difference in degeneration or disc disease between the groups on MR scans was found. Impact ground reaction forces during walking, irrespective of limb, were significantly greater (p < 0.05) in the pain-free group than in the pain group, as was walking speed. Gait asymmetry measures were similar in both groups. Centre of pressure displacement measures during standing were greater in the pain group than in the pain-free group. CONCLUSIONS: Low back pain in amputees is a significant problem equal to that of pain in the phantom limb and a biomechanical (myofascial) rather than a degenerative aetiology is suggested.

Adult traumatic brachial plexus injury.

Injury to the brachial plexus in the adult is usually a closed injury and the result of considerable traction to the shoulder. Brachial plexus injury in the adult is an increasingly common clinical problem. Recent advances in neurosurgical techniques have improved the outlook for patients with brachial plexus injuries. The choice of surgical procedure depends on the level of the injury and the radiologist has an important role in guiding the surgeon to the site of injury. This article will describe the anatomy and pathophysiology of traction brachial plexus injury in the adult. The neurosurgical options available will be described with emphasis on the information that the surgeon wants from imaging studies of the brachial plexus. The relative merits of MRI and CT myelography are discussed.

Diagnosis of pneumothorax in critically ill adults.

The diagnosis of pneumothorax is established from the patients' history, physical examination and, where possible, by radiological investigations. Adult respiratory distress syndrome, pneumonia, and trauma are important predictors of pneumothorax, as are various practical procedures including mechanical ventilation, central line insertion, and surgical procedures in the thorax, head, and neck and abdomen. Examination should include an inspection of the ventilator observations and chest drainage systems as well as the patient's cardiovascular and respiratory systems.Radiological diagnosis is normally confined to plain frontal radiographs in the critically ill patient, although lateral images and computed tomography are also important. Situations are described where an abnormal lucency or an apparent lung edge may be confused with a pneumothorax. These may arise from outside the thoracic cavity or from lung abnormalities or abdominal viscera inside the chest.

Problem in diagnostic imaging: a patient with sciatica.

This article presents the imaging findings in a patient with sciatica. The reader is invited to identify the labeled anatomical structures and the lesions present. The discussion focuses on the anatomy of the lumbar spine and the relative merits of the various methods of imaging a patient with sciatica.

Therapeutic impact of percutaneous spinal biopsy in spinal infection.

OBJECTIVE: To investigate the therapeutic impact of percutaneous spinal biopsy in patients with suspected spinal infection. DESIGN AND PATIENTS: A review of the case notes and imaging features of 36 patients who underwent percutaneous spinal biopsy was performed. From this group 20 patients with a prebiopsy diagnosis of spinal osteomyelitis were identified. Management before biopsy was noted including the use of antimicrobial therapy. The results of the histology and microbiology were noted along with the subsequent diagnosis and management. RESULTS: Eight of the 20 patients (40%) had received antibiotics before the biopsy. An organism was isolated in 8/20 cases (40%). Of the eight patients on antibiotics, two grew an organism (25%), including one case of candida in a patient receiving flucloxacillin. Out of 12 patients not on antibiotics there were six cases where an organism was isolated (50%). The result of the biopsy led to a change in management in seven of the 20 patients (35%). CONCLUSIONS: Many clinicians are treating spinal osteomyelitis empirically with antibiotics before biopsy, but this reduces the chance of isolating an organism and determining antibiotic sensitivity. Despite this biopsy led to a change in management in 35% of cases.

The therapeutic impact of lumbar spine MRI on patients with low back and leg pain.

UNLABELLED: The influence of lumbar spine magnetic resonance imaging (MRI) on the management of patients with low back and leg pain, with a clinical diagnosis of neural compression, has been investigated by a controlled prospective observational study. The clinical features of the patients at the time of request for MRI have been compared with the subsequent management in order to define the clinical indications for lumbar spine MRI. METHODS: Clinical history, physical examination findings and tests of functional and psychological disability were all recorded at the time of request for MRI. Following MRI, patients were assessed without knowledge of the MRI findings and a diagnosis and management plan recorded. Immediate access to the MRI report and hard copy films was then provided and a revised diagnosis and management plan made. The clinical features and MRI findings were compared with the subsequent management. RESULTS: Seventy-two patients were examined, 65 (90.3%) had leg pain as a predominant feature and abnormalities in neurological examination were found in 31 (43%). Twenty-three of 48 (47.9%) of patients with a pre MRI management plan of surgery were changed to conservative management following the MRI. The diagnosis altered in 50 % of cases with the largest change in diagnosis occurring in 13 patients where MRI did not confirm the clinical impression of nerve root compression. Seventeen patients with no abnormality of neurological testing were subsequently treated by surgery which included all 12 patients treated by spinal fusion. CONCLUSIONS: The major impact of MRI was to move patients towards conservative treatment. A variety of features in the history and physical examination as well as MRI findings are predictors for surgical treatment. The variety of diagnoses and surgical options available make it difficult to define clear clinical guidelines for the use of MRI.