Accuracy of Sonography in Plantar Plate Tears in Cadavers.

OBJECTIVES: Sonography is often used in the evaluation of forefoot disorders, and its use has been suggested in the diagnosis of plantar plate tears. This study aimed to assess the accuracy of sonography in the diagnosis of plantar plate tears of the lesser digits using gross dissection as the reference standard. METHODS: The second through fifth digits of 6 cadavers were examined with sonography to evaluate for plantar plate tears. The examination was performed by a single musculoskeletal radiologist in longitudinal and short axes, and plates were graded as torn or intact. The digits were then dissected by a single podiatrist blinded to the prior sonographic results to assess the integrity of the plates. RESULTS: Ten plantar plates were graded as torn by sonography, all occurring in the distal plate near the phalangeal insertion. Seven of these plates were identified as torn on direct inspection. Fourteen plantar plates were found to be intact on sonography, 12 of which were intact on gross inspection. Overall, the accuracy, sensitivity, and specificity of sonography were 79.2%, 77.8%, and 80.0%, respectively. No correlation was seen between the accuracy of sonography and plate size, using plate number as a surrogate marker for plate size (P = .822). CONCLUSIONS: Sonography is an appropriate modality in the setting of suspected plantar plate tears, with acceptable accuracy, sensitivity, and specificity. No decline in accuracy was seen with smaller plates. Thus, sonography may be especially useful when small anatomy or technical factors make magnetic resonance imaging challenging to perform and interpret.

Sonographic evaluation of hip joint effusion in osteoarthritis with correlation to radiographic findings.

PURPOSE: Hip joint effusion is expected in rapidly destructive osteoarthritis, a diagnosis often only made retrospectively at the end stage of the disease. This study assesses whether the presence of an effusion identified during routine ultrasound-guided hip injection may suggest a more aggressive process such as rapidly destructive osteoarthritis. METHODS: After the observation of 10 index cases of rapidly destructive osteoarthritis in patients who presented with a joint effusion on ultrasound, we retrospectively reviewed 94 hips from 89 patients who underwent ultrasound-guided hip injection for pain. Preinjection longitudinal ultrasound images of the anterior capsule adjacent to the femoral neck and inferior to the femoral head were reviewed to determine if a joint effusion was present and the size of the effusion if one was there. Comparison of effusion size was then made between those hips that had a clinical and radiographic diagnosis of osteoarthritis and those who had rapidly destructive osteoarthritis by comparing the severity of joint effusion, if one was present. RESULTS: Patients with rapidly destructive osteoarthritis were more likely to have a large joint effusion 60% (3/5) than were those with osteoarthritis 6.7% (6/89) (p = 0.013). CONCLUSIONS: Large joint effusions identified sonographically correlate well with radiographic findings of rapidly destructive osteoarthritis. Given rapid onset and severity of the disease, when a large joint effusion is identified on routine hip intervention, patients should be forewarned of the potential for this disease process.

Subtle lung nodules: influence of local anatomic variations on detection.

PURPOSE: To assess the influence of local anatomic noise on the detection of subtle lung nodules depicted on chest radiographs. MATERIALS AND METHODS: Six 8 x 8-cm lung regions were extracted from digital chest radiographs obtained in healthy subjects. Simulated nodules emulating the radiographic characteristics of subtle tissue-equivalent lesions 3.2-6.4 mm in diameter (equivalent to 0.1-0.4 mm in contrast-diameter product [CD]) were added to the images. On multiple renditions of each image, nodules were inserted at slightly different locations within 6 mm of the center; this process allowed different local background patterns to overlie the nodules. An observer detection study involving 15 experienced radiologists was performed. The authors performed analysis of variance and pairwise t test analyses to determine variations in nodule detectability related to nodule location and size on each image. RESULTS: Results indicated a strong correlation between nodule size and observer detection score and significant variation in nodule detectability as a function of location. Changes in nodule position caused observer score variations that were equivalent to the variation caused by an up to 185% change in nodule CD (78% average over all six images), an up to 68% change in diameter (32% average), and an up to 28% change in area under the receiver operating characteristic curve (Az) (14% average). CONCLUSION: Local anatomic variations surrounding and overlying a subtle lung nodule on a chest radiograph that are created by the projection of anatomic features in the thorax, such as ribs and pulmonary vessels, can greatly influence the detection of nodules, altering the Az by as much as 28%.

Developmental lung anomalies in the adult: radiologic-pathologic correlation.

Encountering a developmental lung anomaly in the adult can be a challenge, as the abnormality may be mistaken for something more sinister. The common anomalies encountered are classified into three broad categories: bronchopulmonary (lung bud) anomalies, vascular anomalies, and combined lung and vascular anomalies. The imaging features of these developmental anomalies at conventional radiography, ventilation-perfusion lung nuclear scanning, angiography, computed tomography, and magnetic resonance imaging are useful in differential diagnosis of thoracic lesions. Lung bud anomalies include agenesis, congenital bronchial atresia, congenital lobar emphysema, congenital cystic adenomatoid malformation, pulmonary bronchogenic cysts, tracheal or pig bronchus, and accessory cardiac bronchus. Vascular anomalies include interruption or absence of a main pulmonary artery, anomalous origin of the left pulmonary artery from the right, anomalous pulmonary venous drainage (partial or complete), and pulmonary arteriovenous malformation. Combined lung and vascular anomalies include the hypogenetic lung (scimitar) syndrome and bronchopulmonary sequestration, both intralobar and extralobar.