Anthony J. Doyle

Lipoma arborescens in the bicipital bursa of the elbow: MRI findings in two cases.

Abstract. Lipoma arborescens is rare and usually found in the knee. We report two cases in the bicipital bursa of the elbow that showed characteristic findings on magnetic resonance imaging with contrast enhancement.

The “penumbra sign” on T1-weighted MRI for differentiating musculoskeletal infection from tumour

ObjectiveThe “penumbra sign” on unenhanced T1-weighted MR sequences is thought to be helpful for discriminating subacute osteomyelitis from bone neoplasm. We sought to quantify the sensitivity and specificity of this sign for bone and soft tissue infection in a general referral population.DesignClinical coding was used to identify patients admitted to Middlemore Hospital (Auckland, New Zealand) between January 2000 and November 2003 with a diagnosis of either infection or neoplasm of the upper or lower limb who had undergone an MRI scan. One hundred and eighty-three patients were included in the study. Fifty-seven patients had bone or soft tissue infection. One hundred and twenty-six had a bone or soft tissue neoplasm. Relevant unenhanced T1-weighted images were selected for each patient, randomised and placed in a folder on the Hospital PACS system. Four reviewers were shown the original article describing the penumbra sign and then asked to look at the images in the folder stating whether the penumbra sign was present or absent.ResultsThe average specificity and sensitivity of the penumbra sign for musculoskeletal infection was 96% (range 94–99%) and 27% (range 21–34%) respectively. Interobserver reliability was moderate to good with an average kappa score of 0.57 (range 0.50–0.62). For isolated soft tissue infection there was a higher sensitivity (54%, 33–83%) but with similar specificity (98%, 96–100%) and interobserver reliability (0.47, 0.33–0.58). Of the 11 out of 57 (19%) true positive penumbra signs identified by a consensus of three or more of the observers, all were subacute, chronic or acute on chronic infections.ConclusionsThe penumbra sign has a high specificity for musculoskeletal infection. This is also true for isolated soft tissue infection. The penumbra sign is helpful in differentiating neoplasm from infection and its presence in the setting of a high pretest probability is useful in making a diagnosis of infection.

Interstitial fluid and hypoechoic wall: two sonographic signs of breast abscess.

Many mammographic and sonographic features of breast abscess overlap with those of carcinoma. We reviewed the usefulness of interstitial fluid and hypoechoic walls in the sonographic diagnosis of breast abscess.

The lateral chest X-ray: Is it necessary for emergency department patients?

To determine the utility of the lateral view of the chest in emergency department patients, records of all patients who had had 2-view chest x-rays ordered in the emergency department were reviewed retrospectively. A study radiologist recorded a reading of the posteroanterior (PA) radiograph alone. The lateral radiograph was then provided, along with the PA view, and a second reading was recorded. A comparison was then made between the first and second readings.A total of 417 sets of x-rays were included. The PA view alone successfully diagnosed or suspected 92% of pulmonary nodules, 95% of effusions, 97% of cases of emphysema, 98% of pneumonias, and 100% of cases of cardiomegaly, pulmonary edema, interstitial pulmonary disease, and atelectasis.In the emergency department patient population, lateral views of the chest have minimal diagnostic yield and therefore may be used selectively to safely decrease the amount of breast radiation exposure to young women.

Justification for Decreasing the Number of Views Taken in Radiologic Follow-Up of Casper Plate Cervical Spine Hardware

RATIONALE AND OBJECTIVES We tested the null hypothesis that there would be no difference between the diagnostic yield of the lateral radiograph alone and the yield of the lateral and anteroposterior views combined when assessing patients after placement of an anterior cervical appliance. METHODS We evaluated 630 radiographic examinations obtained from 117 consecutive patients who had anterior cervical plating. For each examination, we looked at the lateral radiograph first and then at the anteroposterior radiography to determine whether there would be any additional information on the anteroposterior film. RESULTS Of 501 examinations in which the lateral and anteroposterior views were available, we found that the anteroposterior view added information in 18. In eight of the 18, the added information consisted only of clinically insignificant tilting of the plate. Significant findings were seen in 209 examinations in the lateral view and in 219 examinations with the lateral and anteroposterior views combined. This was not significantly different. CONCLUSION The anteroposterior view rarely adds significant information. It probably should be obtained early postoperatively to check for tilting of the plate but after that only for specific indications. This will save money and reduce the patients exposure to radiation.