Peripatellar synovitis: comparison between non-contrast-enhanced and contrast-enhanced MRI and association with pain. The MOST study.

PURPOSE: To assess the diagnostic performance of signal changes in Hoffa's fat pad (HFP) assessed on non-contrast-enhanced (CE) magnetic resonance imaging (MRI) in detecting synovitis, and the association of pain with signal changes in HFP on non-CE MRI and peripatellar synovial thickness on CE MRI. METHODS: The Multicenter Osteoarthritis (MOST) Study is an observational study of individuals who have or are at high risk for knee OA. All subjects with available non-CE and CE MRIs were included. Signal changes in HFP were scored from 0 to 3 in two regions using non-CE MRI. Synovial thickness was scored from 0 to 2 on CE MRI in five peripatellar regions. Sensitivity, specificity and accuracy of HFP signal changes were calculated considering synovial thickness on CE MRI as the reference standard. We used logistic regression to assess the associations of HFP changes (non-CE MRI) and synovial thickness (CE MRI) with pain from walking up or down stairs, after adjusting for potential confounders. RESULTS: A total of 393 subjects were included. Sensitivity of infrapatellar and intercondylar signal changes in HFP was high (71% and 88%), but specificity was low (55% and 30%). No significant associations were found between HFP changes on non-CE MRI and pain. Grade 2 synovial thickness assessed on CE MRI was significantly associated with pain after adjustments for potential confounders. CONCLUSION: Signal changes in HFP detected on non-CE MRI are a sensitive but non-specific surrogate for the assessment of synovitis. CE MRI identifies associations with pain better than non-CE MRI.

A comparison of dedicated 1.0 T extremity MRI vs large-bore 1.5 T MRI for semiquantitative whole organ assessment of osteoarthritis: the MOST study.

OBJECTIVE: To date semiquantitative whole-organ scoring of knee osteoarthritis (OA) relies on 1.5 Tesla (T) Magnetic resonance imaging (MRI) systems. Less costly 1.0 T extremity systems have been introduced that offer superior patient comfort, but may have limitations concerning field-of-view and image quality. The aim of this study was to compare semi-quantitative (SQ) scoring on a 1.0 T system using 1.5 T MRI as the standard of reference. METHODS: The Multicenter Osteoarthritis Study (MOST) is a longitudinal study of individuals who have or are at high risk for knee OA. A sample of 53 knees was selected in which MRI was performed on a 1.0 T extremity system as well as on a 1.5 T scanner applying a comparable sequence protocol. MRIs were read according to the Whole Organ Magnetic Resonance Imaging Score (WORMS) score. Agreement was determined using weighted kappa statistics. Sensitivity, specificity and accuracy were assessed using the 1.5 T readings as the reference standard. In addition the number of non-readable features was assessed. RESULTS: Agreement (w-kappa) for seven main WORMS features (cartilage, bone marrow lesions (BMLs), osteophytes, meniscal damage and extrusion, synovitis, effusion) ranged between 0.54 (synovitis) and 0.75 (cartilage). Sensitivity ranged between 68.1% (meniscal damage) and 88.1% (effusion). Specificity ranged between 63.6% (effusion) and 96.4% (BMLs). Although the overall rate of non-readable features was very low, it was higher for the 1.0 T system (1.9% vs 0.2%). CONCLUSIONS: Semiquantitative whole organ scoring can be performed using a 1.0 T peripheral scanner with a moderate to high degree of agreement and accuracy compared to SQ assessment using a 1.5 T whole body scanner. Our results are comparable to the published inter- and intra observer exercises obtained from 1.5 T systems. Sensitivity to change of longitudinal scoring was not evaluated in this cross-sectional design and should be investigated in future validation studies.

Lumbosacral nerve root avulsions: MR imaging demonstration of acute abnormalities.

Most of the previously reported lumbosacral nerve root avulsions presented with pseudomeningoceles at the time of delayed initial imaging. We report a case of traumatic lumbosacral nerve root injury associated with an isolated femur fracture and demonstrate the evolution of pseudomeningoceles following nerve root avulsions and edema in the perineural fat identified on the initial MR imaging.

Curriculum for musculoskeletal radiology.

Although general suggestions have been made regarding a radiology residency curriculum, no specific list of entities has been offered. Over the past ten years, we have developed a resident-run morning conference in musculoskeletal radiology that is supervised by faculty and covers a specific curriculum. We offer our curriculum as an example that may assist other departments in developing their own curricula.

Satisfaction of search in diagnostic radiology.

A subset of underreading errors (false-negative responses) in radiology has been attributed to "satisfaction of search," which occurs when lesions remain undetected after detection of an initial lesion. This phenomenon has not been studied in the experimental laboratory. A primary goal of this study was to develop a procedure or paradigm to study satisfaction of search. The authors measured detection accuracy for native lesions in images before and after the addition of a simulated nodular lesion. Simulated and native lesions were not spatially superimposed and the native abnormalities were physically identical with and without the nodules. Only responses related to the native lesion were analyzed. Accuracy parameters of receiver operating characteristic (ROC) curves were estimated by the method of maximum likelihood and jackknife. The average perceptual accuracy of the individual ROC curves as measured by Az and de' was significantly reduced with addition of the nodules (t = 2.364, p = 0.025, t = 2.648, p = 0.017, respectively). Az and de' parameters of the pooled ROC curve showed a similar effect (t = 1.573, p = 0.080; t = 1.934, p = 0.047, respectively). The results indicated a substantial satisfaction-of-search effect, with diminished accuracy in perception of native lesions.

Correct placement of epidural steroid injections: fluoroscopic guidance and contrast administration.

We prospectively evaluated 316 caudal-approach epidural steroid injections given by staff radiologists and residents in our department over a 1-year period. Needle placement was checked with fluoroscopy and corrected if necessary. When the needle tip was within the sacral canal, nonionic contrast material was injected. If epidural contrast was not observed, the needle tip was repositioned. Of 111 procedures performed by physicians who had given fewer than 10 epidural steroid injections, 53 (47.7%) resulted in correct nonfluoroscopically directed placement of the needle. For physicians who had performed between 10 and 50 such procedures, 62 (53.4%) of 116 had correct nonfluoroscopically directed placement. For staff physicians, 55 (61.7%) of 89 placements were correct. Even when the sacral hiatus was easily palpated and a staff physician was confident that he or she was within the epidural space, fluoroscopy revealed incorrect placement 14.2% of the time (seven of 49 procedures). In addition, when the needle was positioned within the sacral canal and no blood was evident on Valsalva maneuver or aspiration, the injection was venous in 29 of 316 procedures (9.2%). The presence of blood on the needle stylus was not a reliable indicator of venous placement of the needle. Our findings indicate that fluoroscopy is essential for correct placement of epidural steroid injection. Contrast administration is necessary to avoid venous injection of steroids.

Thoracic and lumbar spine trauma.

The thoracic and lumbar regions of the spine have unique anatomic and biomechanical features that result in different characteristic patterns of injury. This article reviews common injuries to the thoracic and lumbar spine and emphasizes the relationship between anatomic features and characteristic patterns of injury. An approach to imaging of the trauma patient is presented, focusing on detection and classification of spinal injuries.

Role of MR imaging in acute injuries to the appendicular skeleton.

Clinical applications of MR imaging in the setting of acute extremity injuries are discussed in general and by anatomic regions. General indications include physeal injuries, occult fractures, stress fractures, musculotendinous injuries, and ligamentous injuries. Indications of MR imaging in the acute injury setting have been expanding. MR imaging is often used to triage patients definitively to surgical versus conservative treatment for such conditions as suspected hip fracture. High-performance athletes are also often imaged acutely. Radiologists need to be familiar with the possible applications of MR imaging to acute extremity injuries, and discuss with referring physicians what indications are appropriate locally. In this way, the role of MR imaging in this area will be further defined in the future.

Acute and chronic avulsive injuries.

Avulsive injuries are common traumatic lesions, especially in young athletes. They can be acute, resulting from excessive tensile forces, or chronic, due to overuse. Avulsion injuries can resemble osteomyelitis or neoplasm and, therefore, familiarity with the radiographic patterns as well as the different muscle attachments is helpful for the clinician to arrive at the correct diagnosis. This article discusses acute and chronic avulsive injuries in the pelvis, knee, elbow, shoulder, and foot.

Percutaneous epidural and nerve root block and percutaneous lumbar sympatholysis.

Epidural steroid injections and selective nerve root blocks currently are considered standard techniques in the diagnosis and treatment of back pain. The targeted epidural and perineural steroid injection with nerve block is a new technique that combines an epidural steroid injection and a nerve block. Radiologists are best suited for performing these procedures because of their training and skills in fluoroscopy and needle procedures.

Seronegative spondyloarthropathies.

The seronegative spondylarthropathies are a group of multisystem inflammatory disorders that share a variety of clinical, radiologic, and genetic features. They include ankylosing spondylitis, psoriatic arthritis, Reiter's disease, and arthritis associated with inflammatory bowel disease. This article reviews these multisystem inflammatory disorders.

Treatment options in primary Ewing's sarcoma of the spine: report of seven cases and review of the literature.

Primary Ewing's sarcoma of the spine is reviewed, and seven cases are presented. Ewing's sarcoma of the spine is a rare condition that appears with a clinical triad of local pain, neurological deficit, and a palpable mass. The clinical picture, imaging characteristics, and management are discussed. The definitive management of Ewing's sarcoma of the spine, as in other locations, could include three main modalities: surgery, radiotherapy, and combination chemotherapy. In the presence of acute neurological decompensation, decompressive surgery via an appropriate approach should be performed. Because Ewing's sarcoma is usually sensitive to chemotherapy, initial chemotherapy, in neurologically stable patients, could be attempted first without surgical resection. Further management could then be gauged according to the response.

Occult sacral fractures in osteopenic patients.

The presentation, diagnosis, and treatment of occult sacral fractures in seventeen osteopenic patients were reviewed. Sixteen of the seventeen patients were elderly women, and the fracture usually occurred without trauma (fourteen patients). In ten patients, the sacral fracture was associated with a fracture of the pubic ramus. The sacral fractures were difficult to diagnose because nine patients also had a history of a malignant lesion of the pelvis with or without radiation treatment. Computed tomography and bone-scanning were diagnostic in all patients, but magnetic resonance imaging was not specific. Use of crutches or a walker, a reduction in activity, and use of non-narcotic analgesics allowed for the resolution of symptoms in all twelve patients who did not have mitigating conditions and permitted these patients to walk independently.

Diagnosis of infection in ununited fractures. Combined imaging with indium-111-labeled leukocytes and technetium-99m methylene diphosphonate.

The results of combined scintigraphy in which indium-111-labeled leukocytes and technetium-99m methylene diphosphonate were used were compared with the results of cultures of open bone at 102 sites of delayed union or non-union, to determine the effectiveness of this combination as a preoperative indicator of osteomyelitis. There were twenty-five true-positive, fifty-nine true-negative, eleven false-positive, four false-negative, and three indeterminate interpretations, yielding, for the diagnosis of osteomyelitis, a sensitivity of 86 per cent, a specificity of 84 per cent, an accuracy of 82 per cent, a positive predictive value of 69 per cent, and a negative predictive value of 94 per cent. There were few false-negative scans; false-positive results were most likely at a metaphyseal site adjacent to a joint in which there was post-traumatic arthropathy, at the site of a failed arthrodesis, and at the site of an unstable delayed union or non-union.

Fine-needle aspiration biopsy of bone.

The technique of fine-needle aspiration biopsy seems to be ideally suited for the diagnosis of lytic bone lesions at practically any location in the skeleton. The technique is simple, carries minimum risks, and can often be performed on an outpatient basis. Advances in cytological techniques have made it possible to reach an accurate diagnosis for most patients within twenty-four hours. The accuracy rate in the present study of seventy patients was 87.5 per cent, but the lesions studied included few primary bone tumors. One limitation of the technique is the difficulty in sampling a lesion that is covered by compact bone.

Delayed post-traumatic vertebral collapse (Kummell's disease): case report with serial radiographs, computed tomographic scans, and bone scans.

A case of delayed posttraumatic vertebral collapse (Kummell's disease) is described and documented with serial radiographs, computed tomographic scans, and bone scans. The bone scan was normal before the back injury occurred and showed increased radionuclide uptake 3 weeks after injury and before vertebral collapse. Plain radiographs and computed tomographic scans taken during the interval between injury and collapse revealed no evidence of fracture or bone destruction. The authors believe this represents the first example of Kummell's phenomenon documented with serial computed tomographic and bone scans, and provides further support to the ischemic necrosis theory as the underlying process.

Radiologic evaluation of dens fracture. Role of plain radiography and tomography.

A retrospective study of 50 dens fractures was performed. In 47 of 50 cases (94%), plain radiographs disclosed the fracture. Initial cross-table lateral view alone showed the fracture in 43 cases. In the remaining four cases, routine plain films revealed the fracture: open-mouth view in three cases and lateral skull view in one case. In 3 of 50 cases (6%), plain films were negative, and fractures were seen only on tomography. Conventional circular tomography was performed in 26 cases; results were divided into 3 categories according to the significance of the findings: Category I, tomography confirmed plain radiographic findings, but added no further information; Category II, tomography detected additional findings or showed the extent of injury better than plain radiography; Category III, fracture was only seen by tomography. There were 19 cases in Category I, 4 in Category II, and 3 in Category III. Careful evaluation of plain radiographs remains the primary method for diagnosis of dens fractures. Tomography should be performed whenever plain radiographs or clinical symptoms are suspicious for dens fracture. In addition, tomography is useful to define the fracture level and pattern, which are important factors in the management of these injuries.

Radiographic evaluation of cervical spine injuries.

This study involves an evaluation of specific radiologic patterns of various cervical spine injuries on plain radiographs in order to determine a rational approach for further radiologic investigation and resultant treatment. We retrospectively reviewed 236 patients with 319 cervical spine injuries. Fractures included 50 of the dens, 21 hangman, 4 Jefferson, 29 burst, 24 compression, 32 corner/teardrop, 65 facet, 24 lamina, and nine pedicle. Dislocations included one occipitoatlantal, two atlantoaxial rotatory, and 28 facet. Pleuridirectional tomography performed in 137 cases and computerized tomography was performed in 26. The cases were divided into three groups according to the significance of their radiographic findings: Group I: no additional information was added by the additional radiographic studies compared to the plain radiographs. Group II: the additional radiographic studies changed the extent or type of injuries seen on the plain radiographs. Group III: plain radiographs were negative. The abnormalities were only found on the additional radiographic studies. Results of 137 patients undergoing tomography: 62 were in group I, 64 were in group II, and 11 were in group III. Of the 26 patients undergoing computerized tomography, 13 were in group I, 13 were in group II, and no patients were in group III. Specific fracture types were reviewed according to the distribution of the three groups. We concluded that pleuridirectional tomography appears to be particularly advantageous in patients with injuries involving the facets. Computerized tomography appears to add the most additional information in patients with laminar and posterior element fractures and C1 fractures. We feel that timely and accurate diagnosis of cervical spine injuries is essential.(ABSTRACT TRUNCATED AT 250 WORDS)

The virtual hospital. Providing multimedia decision support tools via the Internet.

Physicians in the clinical setting remain isolated from important sources of medical information. The authors have created a multimedia database known as The Virtual Hospital that improves access to current medical data, which is used to improve patient care decisions. The Virtual Hospital is a digital health sciences library stored on a server (computer) at The University of Iowa and delivered via the Internet to inexpensive personal computers in the workplace. The emerging standard of the World Wide Web is used to provide cross-platform distribution.

Long-term follow-up of lower lumbar fusion patients.

To determine the long-term effects of lower lumbar fusion, 94 subjects were catalogued from medical records. They had a lumbar arthrodesis at the third lumbar level or below and their operations were performed before 1964. Twenty-four were not located and 8 were deceased. Sixty-two subjects (72% of available sample) completed a telephone interview; 52 subjects completed a comprehensive low back questionnaire; and 33 subjects returned for physical examination, flexion-extension lateral lumbar spine films, and a limited computerized axial tomographic (CAT) scan. In general, the subjects who returned for complete evaluation were representative of the larger sample. Forty of 62 patients were men. Ages ranged from 41 to 83 years; the median age was 66 years, 6 months. Follow-up ranged from 21 to 52 years; the median follow-up was 33 years. Forty-four percent (27/61) were currently experiencing low-back pain, 57% (35/61) had back pain in the last year. Fifty-three percent (33/62) were using medication. Fifteen percent (9/62) had undergone repeat lumbar surgery, however, only 5% (3/62) required surgery as a late sequela (more than 10 years postoperatively). Forty-two percent (14/33) had lumbar spinal stenosis, but only 15% (5/33) had dural tube measurements less than 100 mm2. Segmental instability above the fusion was present in 45% (15/33). There was a significant correlation between segmental instability and lumbar spinal stenosis (r = .57, P less than .01). Neither radiographic condition correlated with symptoms, however.(ABSTRACT TRUNCATED AT 250 WORDS)