Relationships between material properties and CT scan data of cortical bone with and without metastatic lesions

Breast, prostate, lung, and other cancers can metastasize to bone and lead to pathological fracture. To lay the groundwork for new clinical techniques for assessing the risk of pathological fracture, we identified relationships between density measured using quantitative computed tomography (rhoQCT), longitudinal mechanical properties, and ash density (rhoAsh) of cortical bone from femoral diaphyses with and without metastatic lesions from breast, prostate, and lung cancer (bone with metastases from six donors; bone without metastases from one donor with cancer and two donors without cancer). Moderately strong linear relationships between rhoQCT and elastic modulus, strength, and rhoAsh were found for bone with metastases (0.73相似文献   

Posterior longitudinal ligament ossification myelopathy and hypothyroidism

Two elderly white women with a long history of hypothyroidism and myelopathy showed ossification in posterior longitudinal ligament at their cervical spine. Case histories are presented and the reported association of PLLO with other conditions discussed.     

Predicting proximal femoral strength using structural engineering models

Hip fracture related to osteoporosis and metastatic disease is a major cause of morbidity and mortality. An accurate and precise method of predicting proximal femoral strength and fracture location would be useful for research and clinical studies of hip fracture. The goals of this study were to develop a structural modeling technique that accurately predicts proximal femoral strength; to evaluate the accuracy and precision of this predicted strength on an independent data set; and to evaluate the ability of this technique to predict fracture location. Fresh human cadaveric proximal femora with and without metastatic lesions were studied using computed tomography scan-based three-dimensional structural models and mechanical testing to failure under single-limb stance-type loading. The models understated proximal femoral strength by an average of 444 N, and the precision of the predicted strength was +/- 1900 N. Therefore, the ability to predict hip strength in an individual subject is limited primarily by the level of precision, rather than accuracy. This level of precision is likely to be sufficient for many studies of hip strength. Finally, these models predict fractures involving the subcapital and cervical regions, consistent with most fractures produced experimentally under single-limb stance-type loading.     

Advances in MR imaging of vertebral collapse

Vertebral collapse is a frequently encountered entity in clinical practice. While diagnosing acute, benign traumatic types is usually not complicated, difficulties arise in determining the etiology of vertebral collapse when there is no history of significant trauma, especially in older populations. Considering up to one-third of vertebral collapse in patients with a known primary malignancy are benign, the diagnosis becomes even more difficult when there is a history of malignancy. Additionally, because primary cancer patients may be immunocompromised, the possibility of infectious vertebral collapse should also be entertained. The purpose of this article is to review all recent magnetic resonance imaging aspects of differentiating osteoporotic, malignant, and infectious vertebral collapse.     

Imaging of cervical spine trauma

The cervical spine, supporting such critical structures as the medulla, spinal cord, and cervical nerve roots, can be very challenging to image propertly because of its complex structural anatomy and superimposition of bony and soft tissue parts. In this article, the use and value of the various modalities that image the cervical spine are discussed. Plain radiography remains the best screening tool in the initial evaluation of the cervical spine after trauma. Additional views, such as swimmer's, pillar and lateral flexion, and extension, often are helpful in certain circumstances.     

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.     

Accuracy of MRI patterns in evaluating anterior cruciate ligament tears

 The purpose of this study was to determine the different patterns of anterior cruciate ligament (ACL) tears on MRI and the prevalence and accuracy of these patterns. Images were obtained on high-tesla and low-tesla units and the results compared to determine whether field strength affects the interpretation using the grading system. In 172 patients who underwent knee MRI (109 knees with high-tesla units and 63 knees with low-tesla units) and arthroscopy, there was a total of 91 arthroscopically proven ACL tears. Five patterns of ACL tears were observed and designated as type 1 (diffuse increase in signal on T2-weighted images and enlargement of the ligament, 48%); type 2 (horizontally oriented ACL, 21%); type 3 (nonvisualization of the ACL, 18%); type 4 (discontinuity of the ACL, 11%); and type 5 (vertically oriented ACL, 2%). The positive predictive value (PPV) for type 2, 4, and 5 patterns was 100% for both field strengths; for type 3 PPV was just above 80% for both field strengths. The PPV value for type 1 was 90% for the high-tesla unit and 79% for the low-tesla, unit, which was not statistically significant. Combining the results of both field strengths, the overall sensitivity and specificity were 93% and 89%, respectively. Arthroscopic results were also used to determine the association between meniscal and ACL tears. Only 13% of ACL tears were isolated, the rest being associated with meniscal tears. Forty-five percent of medial meniscal and 50% of lateral meniscal tears were associated with an ACL tear, and 94% of ACLs were torn when both menisci were torn.     

Computed tomography of Paget disease of the skull versus fibrous dysplasia

Objective. Radiologists are often challenged to review CT examinations of the skull without pertinent clinical information or plain radiographs. Skull lesions of fibrous dysplasia (FD) may often be confused with Paget disease (PD). The purpose of this article is to evaluate radiographic similarities and to find the signs that can differentiate PD from FD of the skull on head CT and to describe the CT imaging features of PD and FD. Design and patients. CT scans of the skull in eight cases of PD, 18 cases of FD (13 cases of skull and facial bones, five cases of only facial bones) and 10 normals were studied retrospectively. Results. Ten features were found to be similar in PD and FD and 10 other features were found to be dissimilar. The frequency of the 10 differentiating features was evaluated to determine their reliability in distinguishing one disorder from the other. The differentiating features in order of significance include: (1) “groundglass” appearance, (2) symmetry, (3) involvement of the paranasal sinuses, (4) thickness of the cranial cortices, (5) involvement of the sphenoid bone, (6) orbital involvement, (7) nasal cavity involvement, (8) presence of a soft tissue mass, (9) maxillary involvement, and (10) the presence of cyst-like changes. Conclusion. These 10 signs improve the radiologist’s skill in differentiating FD and PD.     

Intra-articular calcified bodies: detection by computed arthrotomography

We used computed tomography (CT) in six cases to detect and localize intra-articular calcified bodies after double-contrast arthrography and pneumoarthrography . The cases consisted of one wrist, three ankles, and two knees. In one knee, one wrist, and two ankles, CT scanning after double-contrast arthrogram or air arthrogram accurately diagnosed and localized the intra-articular nature of the calcified bodies. In one knee and one ankle, the use of this technique accurately ruled out false-positive loose bodies suspected on the double-contrast arthrograms. Computed tomography after air arthrography or double-contrast arthrography is a simple and accurate technique to detect, localize, or exclude calcified bodies in the joints, and it is a useful adjunct when conventional tomography is inconclusive.