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OBJECTIVE. The purpose of this study is to evaluate the CT and clinical characteristics of in situ pulmonary artery thrombosis (PAT) associated with radiation therapy (RT). MATERIALS AND METHODS. A database search was performed to identify patients who had PAT develop after receiving RT. The CT characteristics of PAT, including the number, location, and appearance of filling defects as well as the presence of associated lung fibrosis, were recorded. The terminology (in situ thrombosis vs acute or chronic pulmonary embolism) used by the interpreting radiologists to describe PAT, the time between the completion of RT and development of PAT, the change in the size of the PAT, and observation of any new thrombi and emboli on follow-up imaging, were also recorded. RESULTS. Of the 27 patients in the study cohort, 22 (81%) had lung cancer and five (19%) had mesothelioma. Most PATs were solitary (93%) and nonocclusive (96%) and formed an obtuse angle to the vessel wall (89%). All PATs were eccentric within the involved PA and were located within the RT volume. The time from completion of RT to initial diagnosis of PAT on CT ranged from 53 to 2522 days (mean, 675 days). Radiation-induced lung fibrosis was present in the ipsilateral lung in all patients. No evidence of additional PA filling defects that suggested embolization were seen on follow-up images of any of the patients, even those who did not receive anticoagulant therapy. CONCLUSION. In situ PAT associated with RT, which to our knowledge has not previously been described in the English literature, has imaging features different from those of acute pulmonary emboli and does not appear to embolize. Radiologist awareness of PAT can facilitate accurate diagnosis and impact management.

OBJECTIVE. The purpose of this study is to evaluate the rate of overdiagnosis of pulmonary embolism (PE) by pulmonary CT angiography (CTA) in a tertiary-care university hospital. MATERIALS AND METHODS. This study is a retrospective review of all pulmonary CTA examinations performed in a tertiary-care university hospital over a 12-month period. Studies originally reported as positive for PE were retrospectively reinterpreted by three subspecialty chest radiologists with more than 10 years’ experience. A pulmonary CTA was considered negative for PE when all three chest radiologists were in agreement that the pulmonary CTA study was negative for PE. The location and potential causes for PE overdiagnosis were recorded. RESULTS. A total of 937 pulmonary CTA studies were performed over the study period. PE was diagnosed in the initial report in 174 of these cases (18.6%). There was discordance between the chest radiologists and the original radiologist in 45 of 174 (25.9%) cases. Discordance occurred more often...

OBJECTIVE. Vulvar carcinoma is a rare malignancy, most commonly seen in elderly women. Survival depends on the lymph node status. Lymph node–negative patients have a 5-year survival of 90%, whereas survival drops to about 50% in patients with positive lymph nodes. The purpose of this article is to familiarize the reader with the revised International Federation of Gynecology and Obstetrics (FIGO) staging of vulvar cancer and incorporate it into daily practice when interpreting cross-sectional imaging studies. CONCLUSION. Although vulvar cancer is diagnosed clinically, cross-sectional imaging plays an important complimentary role in staging of the tumor, assessing extent of disease, and selecting operable versus inoperable candidates to ultimately help in decreasing morbidity and increasing survival in these patients.

OBJECTIVE. The purpose of this study was to assess the radiographic features of pulmonary fusariosis, an increasingly encountered cause of severe opportunistic mold pneumonia.CONCLUSION. Pulmonary fusariosis has radiographic manifestations that are suggestive of an angioinvasive mold. Nodules or masses were the most common findings at CT, seen in 82% of patients compared with only 45% on chest radiography. The halo sign was not seen. Chest radiographs showed nonspecific findings in 30% of patients, and findings were normal at presentation in 25%. All of the patients had underlying hematologic malignancies. Thirteen of the 20 patients studied (65%) died within 1 month of diagnosis of pulmonary fusariosis. Because early initiation of intense antifungal therapy offers the best chance for survival in pulmonary fusariosis, early CT and appropriate microbiologic investigation should be obtained in severely immunocompromised patients.

The purpose of this study was to determine the frequency, radiographic findings, and clinical significance of a pulmonary embolism of cement occurring during percutaneous vertebroplasty or kyphoplasty as detected on conventional chest radiography.Chest radiographs were obtained after 69 percutaneous vertebroplasty procedures in 64 patients. Chest radiographs were reviewed retrospectively for the presence of pulmonary emboli of cement, and findings were assessed. The frequency was calculated from the cases treated. Medical records were reviewed for procedure-related complications.The emboli of cement were noted radiographically in three (4.6%) of 65 procedures performed in our institution. All patients with cement emboli had multiple myeloma. The chest radiographic findings were multiple radiographically dense opacities with a tubular and branching shape that were scattered sporadically or distributed diffusely throughout the lungs. All patients with cement pulmonary embolism remained asymptomatic. A correlation of embolism of cement to lungs was found with paravertebral venous cement leak (p0.001) but not with the number of vertebral bodies treated (p = 0.185) or with the type of procedure performed-kyphoplasty versus vertebroplasty (p = 0.98).Pulmonary embolism of cement is seen in 4.6% of patients after percutaneous vertebroplasty or kyphoplasty. The characteristic radiographic findings should be recognized by radiologists.

A potential source of false-positive FDG PET interpretations in oncologic imaging is FDG uptake in brown fat. The purpose of this study was to determine the prevalence, location, and appearance of hypermetabolic brown fat in the mediastinum.All PET/CT scans obtained at our cancer institution from August to October 2003 were retrospectively reviewed for increased FDG uptake in the mediastinum localized to fat on CT. The following features were recorded: location, appearance, maximal standard uptake value (SUV(max)) of hypermetabolic mediastinal brown fat, and presence of extramediastinal brown fat.PET/CT scans were obtained in 845 oncologic patients. Fifteen patients (1.8%) with focal hypermetabolic mediastinal brown fat were identified: nine women and two men (age range, 27-79; mean, 55.1 years) and four children (age range, 5-16 years; mean, 10 years). Hypermetabolic mediastinal brown fat (mean SUV(max), 5.7) was more common in children (4/8) than in adults (11/837) and more common in women (9/372) than in men (2/465). Foci of hypermetabolic brown fat were localized to the paratracheal, paraesophageal, prevascular, and pericardial regions; interatrial septum; and azygoesophageal recess. Five patients had focal hypermetabolic brown fat isolated to the mediastinum. Ten patients also had extramediastinal hypermetabolic brown fat in the neck, thorax, and abdomen. There was no difference in the body weight (p = 0.876) or body mass index (p = 0.538) of patients with hypermetabolic brown fat compared with age- and sex-matched control subjects.Hypermetabolic brown fat can be localized to the mediastinum and manifests as focal increased FDG uptake. Knowledge of this potential pitfall and precise localization with fusion PET/CT are important in preventing misinterpretation as malignancy.

The objective of this study was to compare the sonographic appearance of different abnormalities of the colon to evaluate the role of sonography in their differential diagnosis.We retrospectively reviewed videotaped sonographic examinations of 99 patients with proven diagnoses that included diverticulitis (n = 35), malignancy (n = 20), Crohn's disease (n = 16), pseudomembranous colitis (n = 14), ischemic colitis (n = 9), and ulcerative colitis (n = 5). Data were collected with regard to gut features, including the site of colonic involvement, associated small-bowel involvement, length of diseased segment, stratification, luminal contents, pneumatosis, and diverticula. Perigut features evaluated included abnormal fat, abscess, fistula, and ascites.On sonography, the following features were statistically significant (p.05). Involvement of the small bowel was more common in patients with Crohn's disease than in the remainder of the study population (44% versus 1%). Left-sided colonic disease (91% versus 38%), diverticula (91% versus 3%), and perigut findings (91% versus 57%), including abnormal fat (83% versus 39%) and abscess (34% versus 8%), were features that indicated diverticulitis. Malignant conditions were more common in patients with a greater wall thickness (mean, 26.2 mm versus 10.2 mm), asymmetric involvement (85% versus 39%), loss of stratification (85% versus 20%), absence of perigut findings (65% versus 22%), and involvement of a short diseased segment (70% versus 16%). Involvement of the entire colon (50% versus 2%), luminal contents (64% versus 28%), and ascites (64% versus 26%) were features suggesting pseudomembranous colitis.Although the sonographic appearances of abnormalities of the colon overlap, some sonographic features are helpful in the differential diagnosis of colonic abnormalities.