Mark S. Parker

Female Breast Radiation Exposure During CT Pulmonary Angiography

OBJECTIVE The objective of our study was to estimate the effective radiation dose to the female breast during CT pulmonary angiography compared with other routine diagnostic imaging techniques. MATERIALS AND METHODS We retrospectively reviewed the demographic data of patients who underwent CT pulmonary angiography between May 2000 and December 2002, the diagnostic yield of those studies, and the estimated effective radiation dose to the breast incurred during CT. The estimated effective radiation dose was calculated using the ImPACT CT (Impact Performance Assessment of CT) dosimetry calculator and the CT dose index (CTDI) and was compared with the average glandular dose for two-view screening mammography. RESULTS During the study period, 1,325 CT pulmonary angiograms were obtained. Sixty percent (797) of the scans were obtained on female patients. The mean age of scanned females was 52.5 years (range, 15-93 years). Of the studies performed in females, 401 (50.31%) were negative, 151 (18.95%) were nondiagnostic, and 245 (30.74%) were positive for pulmonary thromboembolism. The calculated effective minimum dose to the breast of an average 60-kg woman during CT was 2.0 rad (20 mGy) per breast compared with an average glandular dose of 0.300 rad (3 mGy) for standard two-view screening mammography. CONCLUSION CT pulmonary angiography delivers a minimum radiation dose of 2.0 rad (20 mGy) to the breasts of an average-sized woman. This greatly exceeds the American College of Radiology recommendation of < or = 0.300 rad (3 mGy) or less for standard two-view mammography. The potential latent carcinogenic effects of such radiation exposure at this time remain unknown. We encourage the judicious use of CT pulmonary angiography and lower doses and nonionizing radiation alternatives when appropriate.

Direct quantification of breast dose during coronary CT angiography and evaluation of dose reduction strategies.

OBJECTIVE The purpose of this study was to quantify the absorbed radiation dose received by the adult female breast during coronary CT angiography (CTA) and to evaluate the effectiveness of various dose reduction strategies. MATERIALS AND METHODS An adult female thoracic anthropomorphic phantom was scanned using eight different clinical coronary CTA protocols that varied in detector configuration (320 × 0.5 mm or 64 × 0.5 mm), x-ray tube activation (full R-R, 65% R-R, or 70-80% R-R), use of tube current modulation, and use of breast shields. Direct dosimetry measurements were performed using Gafchromic film to determine the absorbed breast dose. RESULTS Retrospective helical data acquisition using a 64-detector array and a full cardiac cycle without dose modulation or breast shielding is associated with an average absorbed breast dose of 82.9 mGy. Optimization of coronary CTA technique using a 320-detector array and a 70-80% cardiac phase reduces the absorbed breast dose by 78.9% to 17.5 mGy, whereas breast shields used in isolation reduces breast dose by up to 46.8%. CONCLUSION The implementation of clinically validated coronary CTA protocols using large-area detector acquisition and prospective ECG gating with limited x-ray tube activation results in substantial breast dose savings of up to 78.9% and should be used whenever possible in combination with bismuth breast shields to achieve further dose reduction.

Abdominal aortic injury associated with transverse lumbar spine fracture — Imaging findings

The association of abdominal aortic injury with transverse fractures of the lumbar spine is not well recognized. Three cases are presented with description of a mechanism common to both injuries that may explain this association--that of distraction and hyperflexion, such as occurs in seat-belt injuries. Whenever a transverse lumbar spine fracture following such a mechanism of injury is recognized, the co-existence of an injury to the abdominal aorta should be excluded by aortography if there is any doubt concerning the integrity of the peripheral pulses. This is best performed prior to laparotomy for any associated intraperitoneal injuries. Repeated clinical examination may detect deterioration in those cases with initially normal pulses. Ultimately, detection of the aortic injury rests on a high index of suspicion.

Radiologic signs in thoracic imaging: case-based review and self-assessment module.

OBJECTIVE Chest imaging remains one of the most complicated sub-specialties of diagnostic radiology. The successful interpretation of thoracic imaging studies requires the recognition and understanding of the radiologic signs that are characteristic of many complex disease processes. CONCLUSION The educational objectives for this case-based self-assessment module are for the participant to exercise, self-assess, and improve his or her understanding of important thoracic radiologic signs that are useful in establishing the diagnosis of particular diseases of the chest.

Total Artificial Heart Implantation: Clinical Indications, Expected Postoperative Imaging Findings, and Recognition of Complications

OBJECTIVE The purposes of this article are to review the treatment options for late-stage biventricular heart failure, discuss the clinical indications for total artificial heart (TAH) implantation, illustrate the expected imaging findings after uncomplicated TAH implantation, and highlight the radiologic findings of common and uncommon complications associated with TAH implantation through case examples. CONCLUSION TAH implantation is an effective therapeutic option for the treatment of patients with end-stage biventricular heart failure. The duration of implantation varies depending on a particular patients medical condition and the eventual availability of a human heart for orthotopic transplantation. TAH recipients often undergo imaging with conventional radiography, CT, or both for the assessment of device-related issues, many of which are life-threatening and require emergency management. As the clinical use of the TAH increases and becomes more commonplace, it is imperative that radiologists interpreting imaging studies recognize both the expected and the unexpected imaging findings that affect patient care.

The Hermansky-Pudlak Syndrome

Hermansky-Pudlak Syndrome (HPS) is a rare, inheritable disorder characterized by the classic triad of oculo-cutaneous albinism, platelet dysfunction, and ceroid deposition. An associated complication is pulmonary fibrosis with progressive restrictive lung disease. This report discusses the lung involvement often seen in this condition correlated with radiography, computed tomography, high-resolution computed tomography, and the underlying pathology, by means of two such afflicted siblings. The elder died of respiratory failure while awaiting lung transplantation. The younger sibling is currently undergoing evaluation for transplantation.

Etiology of the Widened Mediastinum: Blunt Thoracic Trauma

Most centers continue to use conventional chest radiography as the principal screening modality for the detection of mediastinal hemorrhage and potential injury to the aorta or great vessels after blunt decelerating trauma. Of the many radiographic signs proposed to suggest potential injury, the mos

Chest imaging case atlas

Chest imaging case atlas / , Chest imaging case atlas / , کتابخانه دیجیتالی دانشگاه علوم پزشکی و خدمات درمانی شهید بهشتی

A 47-Year-Old Woman With Progressive Dyspnea and Recurrent Pneumothoraces

47-year-old woman was referred for evaluation of dyspnea and recurrent bilateral pneumothoraces, with the last episode requiring left apical resection and talc pleurodesis. The pathology from this procedure revealed only a scarred bleb lining. Dyspnea was described as insidious and gradually progressive since onset 5 years earlier. The medical history was notable for emphysema. The findings of a review of systems was otherwise negative, as was the family history. A social history revealed a 10 pack-year history of smoking with current use being described as sporadic. The physical examination findings were unremarkable with the exceptions of pulse oximetry values of 82% while breathing room air and a well-healed thoracotomy scar. The data available at the time of referral included normal serum chemistry levels, CBC, and 1-antitrypsin levels, along with pulmonary function test (PFT) results that revealed an FEV1 74% of predicted, FVC 97% of predicted, and FEV1/FVC ratio 62% of predicted. The diffusing capacity of the lung for carbon monoxide (Dlco) was also 27% of predicted.