Selenium-based digital radiography versus conventional film-screen radiography of the hands and feet: a subjective comparison.

OBJECTIVE: The purpose of this study was to subjectively compare the visibility of normal anatomy of the hands and feet using selenium-based digital radiography versus conventional film-screen (100-speed) radiography. SUBJECTS AND METHODS: Digital and film-screen images of the hands and feet of 24 patients were obtained without an antiscatter grid using identical X-ray exposure. Each pair of images was evaluated independently by five experienced radiologists for visibility of normal anatomy using a six-point rating scale. Soft tissues, cortical bone, and trabeculae were evaluated. For each observer, "equivalence" was defined as a mean difference in image quality of less than 1 unit on the 0-5 scale used in the study. Paired t tests were also performed to determine whether the average visibility rating of one technique was statistically superior to that of the other at a .05 level of significance for each observer and at each anatomic landmark. RESULTS: In all categories, selenium-based digital images were rated equivalent to film-screen images by the five observers. Using the sum of the nine landmarks, four of the five observers rated the quality of selenium-based digital images superior to that of film-screen images. CONCLUSION: Subjective visibility of normal anatomy of the hands and feet using selenium-based digital radiography was similar to that achieved using conventional film-screen radiography.

Imaging modalities for study of the distal ulnar region.

Judicious use of diagnostic imaging maximizes the diagnostic capabilities of the surgeon treating the distal radio-ulnar joint (DRUJ). A good clinical history and clinical examination are necessary to direct the selection of appropriate imaging studies. Plain radiographs are almost always the first imaging examination. More advanced imaging techniques are costly and may provide only limited information. This article discusses imaging modalities useful for assessment of the DRUJ and the area around it.

Accuracy of fat-suppressed three-dimensional spoiled gradient-echo FLASH MR imaging in the detection of patellofemoral articular cartilage abnormalities.

PURPOSE: To determine the accuracy of T1-weighted fat-suppressed (FS) three-dimensional (3D) fast low-angle shot (FLASH) magnetic resonance (MR) imaging for the detection of articular cartilage abnormalities of the patellofemoral joint. MATERIALS AND METHODS: Forty-one patients with suspected internal derangement of the knee were examined with a T1-weighted FS 3D FLASH sequence and subsequently underwent arthroscopy. The patellofemoral articular cartilage was graded blindly on both the MR and arthroscopic images with a modification of the Noyes classification scheme. RESULTS: For the detection of abnormal articular cartilage of the patellofemoral joint with the FS 3D FLASH sequence, sensitivity was 81%, specificity was 97%, and accuracy was 97%. Of the lesions detected on MR images, 77% were graded identically on MR and arthroscopic images. For the remaining 23%, MR imaging and arthroscopic ratings were within one grade of each other. CONCLUSION: T1-weighted FS 3D FLASH imaging is accurate for the detection and grading of articular cartilage abnormalities of the patellofemoral joint.

Fast spin-echo imaging of the knee: factors influencing contrast.

Conventional T2-weighted spin-echo magnetic resonance imaging of the knee requires a long TR. Fast spin-echo (FSE) imaging can improve acquisition efficiency severalfold by collecting multiple lines of k space for each TR. Compromises in resolution, section coverage, and contrast inevitably result. The authors examined the compromises encountered in FSE imaging of the knee and discuss the variations in image contrast and resolution due to choices of sequence parameters. For short TR/TE knee imaging, FSE does not appear to offer any advantages, since the increased collection efficiency for one section reduces the available number of sections, so that the total imaging time for a given number of sections remains constant relative to conventional spin-echo imaging. For T2-weighted images, considerable time can be saved and comparable quality images can be obtained. This saved time can be usefully spent on increasing both the resolution of the image and its signal-to-noise ratio, while still reducing total acquisition time by a factor of two. The preferred FSE T2-weighted images were acquired with a TR of 4,500 msec, TE of 120 msec, and eight echoes. The available number of sections is compromised, and the sequence remains sensitive to flow artifacts; however, the FSE sequence appears to be promising for knee imaging.

Medial malleolar stress fractures in seven patients: review of the clinical and imaging features.

Stress fractures of the medial malleolus were discovered in seven patients, five male and two female subjects aged 16-34 years. All except one were involved in running and jumping athletic activities. Gradual onset of pain over the medial malleolus occurred with repetitive activity. Focal intense increased uptake in the medial malleolus was present on bone scans. Conventional radiography and computed tomography demonstrated the presence of subtle fissures at the junction of the medial malleolus and the tibial plafond, and well-circumscribed lytic lesions were also seen in three patients. Two patients developed a complete fracture of the medial malleolus. Stress fractures of the medial malleolus should be suspected in patients involved in athletic and/or unusual activities who have experienced persistent and unexplained pain over the medial malleolus. Bone scans and radiographs should be obtained for diagnostic purposes in these patients.

Transient osteoporosis of the hip: clinical and imaging features.

Transient osteoporosis of the hip is a form of reflex sympathetic dystrophy characterized by pain, limping, limitation of hip joint motion, and delayed radiographic patchy osteoporosis of the proximal femur. Spontaneous resolution is usually paralleled by radiographic recovery, usually within a few months. We present clinical and imaging features in seven cases of unilateral transient osteoporosis of the hip. In the appropriate clinical setting, conventional radiography will support the diagnosis. The role of more sensitive imaging techniques such as bone scintigraphy and magnetic resonance imaging in the early diagnosis of this disease has yet to be defined.

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.

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.

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.

Making core decompression work.

Meaningful assessment of a treatment modality for osteonecrosis (ON) must take into account a number of factors: (1) an accurate diagnosis, (2) consistent staging of the disease process, (3) understanding of the variability of the disease, (4) consistent application of the treatment modality (or the surgical technique), and (5) a clear understanding of the goal of the treatment used. This article reviews the important steps of a diagnostic algorithm that has been used to accurately diagnose and stage the disease process of ON. A consistent surgical technique with clearly defined goals is also outlined. The results of two clinical studies that were based on these diagnostic and therapeutic philosophies and that assess the role of core decompression in the treatment of ON are reviewed. The first study compared core decompression to conservative management in a prospective randomized study of 55 hips. Decompression provided more predictable pain relief and changed the indications for further surgical intervention more consistently than did conservative management. The second study represents a preliminary review of a ten-year study of the decompression procedure; it showed that core decompression was particularly useful in Stage I and Stage II ON. Roentgenographic stabilization was most predictable for Stage I hips. Core decompression can be a safe, effective, and predictable procedure in the treatment of Stage I and Stage II ON.

A diagnostic algorithm for osteonecrosis of the femoral head.

For patients considered at risk for osteonecrosis (ON) of the femoral head, an algorithm for the efficient and appropriate use of diagnostic tests can be developed. Such an algorithm requires a clear idea of the evolution of the disease process and an understanding of the limitations of each of the modalities by which the disease process can be identified. The role of each of the diagnostic tests available for the diagnosis of ON and the results of prospective evaluations to assess their sensitivity, specificity, and predictive values are reviewed. No single diagnostic test is 100% accurate in the diagnosis of the disease. Thus, one must consider an algorithm that accounts for the variable nature of the disease presentation. The goal of such an algorithm is the accurate identification and staging of the disease. For disease not roentgenographically apparent, an approach using magnetic resonance imaging and bone scanning is recommended. For disease that is apparent roentgenographically, tomography is used to define the extent of the disease and the presence or absence of subchondral fracture. The accuracy of diagnosis is critical to understanding the role of the various treatment modalities prescribed for ON. For this purpose, it is necessary to reach a consensus as to what constitutes a successful outcome of treatment. Once diagnosis of the disease is accepted, clinical success of treatment outcomes should be reported in three ways: by a standard hip rating system, by ability to prevent roentgenographic deterioration, and by survival of the femoral head (the absence of further treatment intervention).(ABSTRACT TRUNCATED AT 250 WORDS)

Special diagnostic procedures in sports medicine.

In summary, there are a number of imaging procedures available to support the physician in his or her evaluation of sports injuries. Conventional radiographs remain the primary imaging examination. Specialized radiographic projections will often provide additional pertinent information. A fluoroscopic examination or conventional tomography may provide a cost-effective method of clarifying subtle post-traumatic changes. The use of the more sophisticated and costly imaging procedures should be reserved for those cases in which a diagnosis cannot be made with simpler technology. CT scanning, by virtue of its ability to image in the axial plane, has proved to be an effective method of documenting injuries particularly in complex bony anatomy such as the spine, wrist, elbow, and hips. CT arthrography provides diagnostic information about intra-articular structures. MRI is emerging as an excellent method of noninvasively imaging injuries to soft-tissue structures such as tendons, ligaments, and cartilage. The advancements in MRI technology that are projected for the future may expand the range of usefulness of this modality and decrease the current high cost of these procedures. Radionuclide scanning with Tc99m diphosphonate compounds has proved to be an efficient method of localizing subtle bone pathology and providing a "road map" for further analysis with additional imaging techniques. The cost-effective use of all of these imaging procedures is predicated on an understanding of their usefulness in the diagnosis of each clinical problem and the judicious use of each procedure to fit the needs of the individual patient.

Multimodality approach to osteonecrosis of the femoral head.

Treatment of osteonecrosis of the femoral head appears to be effective when the disease is identified and treated early. Forty-one patients were evaluated with prospective laboratory assessment, anteroposterior and frog-lateral roentgenograms of both hips, intraosseous pressure measurements (IOP), magnetic resonance imaging (MRI), and 99mTc methylene diphosphonate planar and single-photon emission computerized tomographic (SPECT) bone imaging. Pathologic specimens were obtained in most patients. Preradiographic disease was identified in 26 hips and 11 of these were asymptomatic. Fifteen clinically symptomatic hips had normal plain roentgenograms, but abnormal protocol studies. Evaluation of sensitivity, specificity, and predictive value (positive and negative), respectively, in diagnosing osteonecrosis of the femoral head revealed the following percentages: 83%, 83%, 96%, and 48% for planar bone scanning; 91%, 78%, 94%, and 70% for SPECT; 87%, 83%, 96%, and 55% for MRI; 80%, 60%, 95%, and 25% for IOP; and 88%, 100%, 100%, and 25% for core biopsy. (There were few true negatives, thus specificity values are approximations.) The identification of preradiographic stages is possible, but difficult. MRI appears appealing at present, particularly in identifying disease in asymptomatic hips. However, there is no definitive method for noninvasive diagnosis. Pathologic confirmation in early stages is difficult.

Acute Posttraumatic Pubic Symphysis Instability in an Athlete.

In brief: A 16-year-old high school football player and wrestler began experiencing groin and pubic pain, and a popping sensation with abduction movements, after sustaining an abduction injury to his lower extremities. Stress roentgenographs revealed instability of the pubic symphysis; there was no evidence of fracture or gross instability of the sacroiliac joints or the posterior sacrum. The patient was treated conservatively for one year, with an initial period of limited weight-bearing and rest followed by progressive stretching and strengthening exercises and a gradual return to full sports activity.

Elbow arthrography in the evaluation of posterior interosseous nerve compression in rheumatoid arthritis.

This is a case report of a fifty-nine-year-old rheumatoid arthritic woman who developed lack in finger extension bilaterally. These deficits had two completely different aetiologies, Posterior Interosseous Nerve (PIN) Syndrome and extensor tendon rupture. No previous report in the literature has used elbow arthrography as a diagnostic tool in a patient with PIN Syndrome. Elbow arthrography confirmed the abnormality at this joint and aided in appropriate management.

Hyperparathyroidism, hyperthyroidism, and Cushing's disease.

In this article, normal and hyperactive states of parathyroid, thyroid, and cortisol production are examined. Their role in bone loss and the rationale for therapeutic intervention are also discussed.

Digital subtraction angiography for preoperative evaluation of extremity tumors.

A retrospective study was undertaken to evaluate the role of digital subtraction angiography (DSA) in the surgical planning of musculoskeletal neoplasms. Thirteen patients with primary bone and soft-tissue tumors were examined by CT and DSA. Three patients also had conventional angiography. DSA yielded surgically useful information in 10 patients, comparable to that expected from conventional angiography. DSA was most helpful in demonstrating the presence or absence of major vessel involvement by tumor when this could not be ascertained definitely on CT. Demonstration of mass extent by CT was accurate in 11 patients. Results of this study suggest that the combination of CT and DSA is useful in the preoperative evaluation of selected extremity tumors and should diminish the need for conventional angiography.