George H. Belhobek

Juxta-articular osteoid osteoma.

Osteoid osteomas that arise at the end of a long bone, within the insertion of the joint capsule (juxta-articular, intra-articular), may cause misleading clinical, radiographic, and histologic findings, resulting in unnecessary diagnostic tests and a delay in definitive treatment. To clarify optimum diagnostic procedures, we reviewed 20 cases of juxta-articular osteoid osteomas and found a mean delay from presentation to correct diagnosis of 24 months. Plain radiographs were either negative or showed only secondary changes. A periosteal reaction and proliferative synovitis with chronic inflammation was common, which could be misinterpreted as rheumatoid arthritis. Optimum diagnostic procedures were a bone scan followed by plain tomograms and an excisional biopsy of the nidus.

Osteosarcoma of the Hand

Two cases of osteogenic sarcoma in the hand are reported, with a discussion of the literature.

Application of an Artificial Neural Network in Radiographic Diagnosis

The description of 44 cases of bone tumors was used by an artificial neural network to rank the likelihood of 55 possible pathologic diagnoses. The performance of the artificial neural network was compared with the performance of experienced (3 or more years of radiology training) residents and inexperienced (less than 1 year of radiology training) residents. The artificial neural network was trained using descriptions of 110 radiographs of bone tumors with known diagnoses. The descriptions of a separate set of 44 cases were used to test the neural network. The neural network ranked 55 possible pathologic diagnoses on a scale from 1 to 55. Experienced and inexperienced residents also ranked the possible diagnoses in the same 44 cases. Inexperienced residents had a significantly lower mean proportion of diagnoses ranked first or second than did the neural network. Experienced residents had a significantly higher proportion of correct diagnoses ranked first than did the network. Otherwise, a significant difference between the performance of the network and experienced or inexperienced residents was not identified. These results demonstrate that artificial neural networks can be trained to classify bone tumors. Whether neural network performance in classification of bone tumors can be made accurate enough to assist radiologists in clinical practice remains an open question. These preliminary results indicate that further investigation of this technology for interpretation assistance is warranted.

Arthroscopic elbow findings: Correlation with preoperative radiographic studies

Correlation between arthroscopic findings and preoperative radiographic studies (plain radiographs and arthrotomograms) was performed in a consecutive series of 37 elbows. Arthrotomograms added significant diagnostic information unavailable from plain radiographs alone, thereby improving the sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic efficiency (accuracy) in the evaluation of elbow joint surface changes, marginal spurs, and loose bodies. Arthrotomograms gave 85% accuracy for bone spurs, 89% accuracy for joint surface abnormalities, and 89% accuracy for loose bodies (88% accuracy overall), whereas plain radiographs demonstrated 69% accuracy for bone spurs, 71% accuracy for joint surface abnormalities, and 75% accuracy for loose bodies (72% accuracy overall). The arthrotomograms had 100% sensitivity for loose bodies as well as a 100% negative predictive value for loose bodies. Arthrotomograms are indicated when additional preoperative diagnostic accuracy is necessary. These radiographic studies approached only 90% accuracy, confirming that diagnostic arthroscopy adds additional information.

Stress fractures of the tarsal navicular A case report

In summary, the diagnosis of a tarsal navicular stress fracture should be entertained in the athlete with ill-defined midfoot pain. Technetium bone scans will often point the clinician in the right direction; biplanar CT scans will pin-point the diagnosis and can be invaluable in perioperative planning. Subsequent treatment, however, must be determined on a clinical rather than a radiographic basis.

Imaging Techniques of Articular Cartilage

Many imaging modalities are currently used to evaluate articular cartilage. Despite the fact that conventional radiography allows only indirect assessment of cartilage, it remains the primary modality for cartilage evaluation in acute and chronic articular disorders. Compared with newer modalities, arthrography has a very limited role in cartilage evaluation. Computed tomography performed after intraarticular injection of contrast material (CT arthro-tomography) is an excellent method for evaluating complex articular anatomy and pathology. More recently, due to its superior soft tissue contrast and multiplanar capability, MRI has made a significant impact in the imaging of the musculoskeletal system. The role of MRI in the assessment of articular cartilage is developing, but it is clear that MRI at present is the best noninvasive method for evaluating articular cartilage. With further technologic improvement, the role of MR in evaluating chondral abnormalities should become larger and better defined.