Radiological features of Paget disease of bone associated with VCP myopathy

Objective  

Mutations in the Valosin-containing protein (VCP) gene cause a unique disorder characterized by classic Paget disease of bone (PDB), inclusion body myopathy, and frontotemporal dementia (IBMPFD). Our objective was to analyze the radiographic features of PDB associated with VCP mutations since there is a dearth of literature on the PDB component of VCP disease.     

Efficacy of limited CT for nonvisualized lower cervical spine in patients with blunt trauma

Records of 100 patients with blunt injury and nonvisualization of C7 and T1 on cross-table lateral and swimmer's views were reviewed to evaluate the usefulness of limited computed tomographic (CT) scans in “clearing”¹ the lower cervical vertebrae of injury. CT was deemed necessary and performed in all of these cases because the lower cervical spine could not be evaluated clinically or with plain radiographs. Ninety-seven of these 100 patients had normal findings on CT and only three patients showed cervical spine fractures. All three had isolated and stable fractures. Two of these patients had “clay-shoveler” fractures at C6 and C7, respectively, and one had a single laminar fracture at C7. All three patients were conservatively treated. This study emphasizes the value of clinical correlation in the evaluation of cervical spine trauma. When deemed necessary in symptomatic patients, CT is useful to exclude skeletal injury in the lower cervical spine thus avoiding delay in the patient's workup and unnecessary hospitalization, and expediting patient discharge. Lack of pain and neurological findings in nonintoxicated, conscious, and alert patients is generally not associated with significant soft tissue or skeletal injury.     

Prospective study of sequential technetium-99m phosphate and gallium imaging in painful hip prostheses (comparison of diagnostic modalities)

Twenty-two painful hip prostheses were studied prospectively with plain radiography, aspiration and arthrography, Tc-99m phosphate bone imaging, and gallium imaging to evaluate loosening, infection, or both and to compare the accuracy of these modalities. Fifteen prostheses were revised yielding 14 loose femoral and eight loose acetabular components. Five proved to have infected prostheses. Arthrograms, plain radiographs, and bone scans are highly sensitive in detecting loosening of the femoral component. This study confirmed a previous retrospective study in demonstrating that accuracy of diagnosis of an abnormal acetabular component using all four modalities is less than that for the femoral component. In infected prostheses, phosphate bone imaging showed high sensitivity of a pattern that accurately diagnosed all the infected cases, whereas gallium imaging missed one case.     

The prone position for CT of the lumbar spine

In scanning the L5-S1 disk space, the known technical difficulty is limitation of the gantry angle. A prone scanning technique used to examine the lumbar spine may help to overcome or lessen this problem. A prospective CT scanning of the L5-S1 level was performed in both the prone and supine positions on 25 patients who had low back pain and who had not undergone previous laminectomy or fusion. The angle between the S1 vertebral end plate and maximum tilted gantry line (15 degrees on the G.E. 8800) was measured in the supine position and compared with the same angle in the prone position. In 20 of 25 cases (80%), significant improvement in alignment was noted in the prone position. The prone scanning technique is also more desirable if CT is performed with metrizamide. Finally, printed images from the prone technique allow easier image-patient orientation for viewing in the operating room.     

Area beam equalization: optimization and performance of an automated prototype system for chest radiography

RATIONALE AND OBJECTIVES: To evaluate the feasibility and performance of an x-ray beam equalization system for chest radiography using anthropomorphic phantoms. MATERIALS AND METHODS: Area beam equalization involves the process of the initial unequalized image acquisition, attenuator thickness calculation, mask generation using a 16 x 16 piston array, and final equalized image acquisition. Chest radiographs of three different anthropomorphic phantoms were acquired with no beam equalization and equalization levels of 4.8, 11.3, and 21. Six radiologists evaluated the images by scoring them from 1-5 using 13 different criteria. The dose was calculated using the known attenuator material thickness and the mAs of the x-ray tube. RESULTS: The visibility of anatomic structures in the under-penetrated regions of the chest radiographs was shown to be significantly (P < .01) improved after beam equalization. An equalization level of 4.8 provided most of the improvements with moderate increases in patient dose and tube loading. Higher levels of beam equalization did not show much improvement in the visibility of anatomic structures in the under-penetrated regions. CONCLUSION: A moderate level of x-ray beam equalization in chest radiography is superior to both conventional radiographs and radiographs with high levels of beam equalization. X-ray beam equalization can significantly improve the visibility of anatomic structures in the under-penetrated regions while maintaining good image quality in the lung region.     

Radiological evaluation of painful total hip replacement

Ninety-four cases of clinically failed, cemented, total hip prostheses requiring surgery were reviewed to determine the accuracy of preoperative plain radiography, culture of aspirated fluid, arthrography, and bone scanning. When radiopaque cement had been used to embed the prosthesis, plain radiography was highly accurate in detecting a loose femoral component, less so in detecting a loose acetabular component. Culture of aspirated fluid was accurate in diagnosing infection. A positive arthrogram identified loosening with good accuracy; however, a negative arthrogram did not reliably exclude loosening. 99mTc bone scans frequently differentiated loosening from loosening with infection. The suggested sequence of diagnostic tests is plain radiography followed by bone scanning. If the bone scan shows diffuse augmented uptake, culture of aspirated fluid followed by arthrography is indicated.