Certified reference materials for radionuclides in Bikini Atoll sediment (IAEA-410) and Pacific Ocean sediment (IAEA-412).

The preparation and characterization of certified reference materials (CRMs) for radionuclide content in sediments collected offshore of Bikini Atoll (IAEA-410) and in the open northwest Pacific Ocean (IAEA-412) are described and the results of the certification process are presented. The certified radionuclides include: (40)K, (210)Pb ((210)Po), (226)Ra, (228)Ra, (228)Th, (232)Th, (234)U, (238)U, (239)Pu, (239+240)Pu and (241)Am for IAEA-410 and (40)K, (137)Cs, (210)Pb ((210)Po), (226)Ra, (228)Ra, (228)Th, (232)Th, (235)U, (238)U, (239)Pu, (240)Pu and (239+240)Pu for IAEA-412. The CRMs can be used for quality assurance and quality control purposes in the analysis of radionuclides in sediments, for development and validation of analytical methods and for staff training.

Certified Reference Material IAEA-446 for radionuclides in Baltic Sea seaweed.

A Certified Reference Material (CRM) for radionuclides in seaweed (Fucus vesiculosus) from the Baltic Sea (IAEA-446) is described and the results of the certification process are presented. The (40)K, (137)Cs, (234)U and (239+240)Pu radionuclides were certified for this material, and information values for 12 other radionuclides ((90)Sr, (99)Tc, (210)Pb ((210)Po), (226)Ra, (228)Ra, (228)Th, (230)Th, (232)Th, (235)U, (238)U, (239)Pu and (240)Pu) are presented. The CRM can be used for Quality Assurance/Quality Control of analysis of radionuclides in seaweed and other biota samples, as well as for development and validation of analytical methods, and for training purposes.

A new Certified Reference Material for radionuclides in Irish sea sediment (IAEA-385).

A new Certified Reference Material (CRM) for radionuclides in sediment (IAEA-385) is described and the results of the certification process are presented. Eleven radionuclides ((40)K, (137)Cs, (226)Ra, (228)Ra, (230)Th, (232)Th, (234)U, (238)U, (238)Pu, (239+240)Pu and (241)Am) have been certified and information mass activities with 95% confidence intervals are given for seven other radionuclides ((90)Sr, (210)Pb((210)Po), (235)U, (239)Pu, (240)Pu and (241)Pu). Results for less frequently reported radionuclides ((60)Co, (99)Tc, (134)Cs, (155)Eu, (224)Ra and (239)Np) and information on some activity and mass ratios are also reported.

"Incisura" of the ascending aorta and vascular pedicle width in the cardiac transplant patient.

Background: The purpose of this study was to evaluate three findings in cardiac transplant patients: the appearance, etiology, and incidence of "incisura" (a characteristic indentation) of the ascending aorta; the vascular pedicle width, which usually appears enlarged on standard chest radiographs; and clearing of the retrosternal clear space.

Material: Two hundred sixty-one cardiac transplantations were performed at the University of Minnesota before December 31, 1992. The appearance, etiology, and incidence of an incisura were studied; the vascular pedicle width was measured; and the rate of clearing of the retrosternal clear space was determined.

Pulmonary venoocclusive disease: CT findings in eight patients.

Objective: The objective of the study was to describe the CT findings of pulmonary venoocclusive disease.

Materials And Methods: Eight patients with CT scans of the thorax and a diagnosis of pulmonary venoocclusive disease were identified from three institutions. The six males and two females had a mean age of 32 years old (range, 5-58 years old).

Imaging of small airways disease.

High-resolution computed tomography (HRCT) is the most useful modality for imaging of small airways disease. Direct signs of small airways disease that appear on HRCT scans are the result of changes in the airway wall or lumen. Abnormal small airways can be seen as tubular, nodular, or branching linear structures on HRCT scans.

Computed tomography correlation in atypical (peripheral) right upper lobe collapse: the minor fissure as an explanation for the pleural-based density.

Peripheral right upper lobe collapse describes the unusual plain film finding in which the collapsed lobe simulates a peripheral, pleural-based mass. Most investigators have postulated that the peripheral opacity is explained by the interface between the superior segment of the lower lobe and the posterior aspect of the collapsed upper lobe, which does not swing as far medial as in the normal pattern of collapse. In our patient, using computed tomography (CT) correlation, we demonstrated that the finding is explained by the interface between the middle lobe and the anterior aspect of the collapsed upper lobe.

Axial and lateral resolution of rotational intravascular ultrasound: in vitro observations and diagnostic implications.

Purpose: To determine the axial and lateral resolution of a rotating intravascular ultrasound system and the diagnostic implications for the diagnosis of early artherosclerosis.

Methods: The resolution of a 20 MHz rotating transducer was tested in a specially designed high-resolution phantom and in five aortic autopsy specimens with varying degrees of early atherosclerosis.

Results: The best lateral resolution is at the minimal distance between transducer and object.

Heart-lung and lung transplantation.

Lung and heart-lung transplantation have evolved into successful therapeutic options in patients with end-stage cardiopulmonary disease. Imaging studies extend from pretransplant evaluation to posttransplant monitoring for complications. Although many radiologic features are considered nonspecific, improved understanding of underlying pathologic and physiologic conditions unique to this population will enhance the clinical impact of the radiologist involved in a transplantation program.

Regional alterations in lung ventilation in end-stage primary pulmonary hypertension: correlation between CT and scintigraphy.

Objective: The purpose of this study was to correlate scintigraphic findings of regional alterations in lung ventilation and perfusion with regional variations in CT attenuation in patients with primary pulmonary hypertension.

Subjects And Methods: Chest CT scans and ventilation-perfusion scans obtained within 24 hr of each other in 18 patients with primary pulmonary hypertension referred for lung transplantation were reviewed. The lungs were divided into eight regions (left/right, superior/inferior relative to the carina, and anterior/posterior relative to the trachea).

Pectus excavatum: abnormal exercise scintigraphy with normal coronary arteries.

Pectus excavatum is the most common congenital abnormality of the chest wall, and is frequently associated with chest pain. The invasive, as well as the ECG and echocardiographic assessment of possible coronary artery disease (CAD) in adults with moderate to severe forms of this deformity, is often complicated by the associated displacement of the heart in the chest cavity in these patients. We present findings in a 67-yr-old male that demonstrate that the predictive accuracy of positive stress radionuclide ventriculogram (RVG) and SPECT scintigraphic studies may be significantly reduced in patients with moderate to severe forms of this abnormality.

Volumetric high-resolution CT in the diagnosis of interstitial lung disease and bronchiectasis: diagnostic accuracy and radiation dose.

Objective: The purpose of this study was to evaluate the diagnostic accuracy and radiation dose of volumetric high-resolution CT in the diagnosis of interstitial lung disease and bronchiectasis when four contiguous sections were acquired at each of three levels. The potential benefits were weighed against the increased radiation dose of multiple scans.

Subjects And Methods: High-resolution CT scans of four contiguous sections were obtained at each of three locations (the aortic arch, the carina, and 2 cm above the diaphragm) in 50 consecutive patients (mean age, 44 years old) with known or suspected interstitial lung disease or bronchiectasis who were referred for evaluation with high-resolution CT.

Alternative design for radiologic guidance in video thoracoscopic surgery.

Rationale And Objectives: Easy dislodgment and a pneumothorax rate of up to 50% have been reported with the use of mammographic hookwires for radiologic guidance in thoracoscopic surgery. An alternative design is described and preliminary in vitro results are reported.

Methods: The new design is based on the T-fastener used in percutaneous gastrostomies and can be deposited with a 20-Fr guidance needle.

Ground-glass opacity of the lung parenchyma: a guide to analysis with high-resolution CT.

Ground-glass opacity is a frequent but nonspecific finding on high-resolution CT scans of the lung parenchyma. The underlying abnormality is diverse; any condition that decreases the air content of the lung parenchyma without totally obliterating the alveoli can produce ground-glass opacity. These processes are not visible on high-resolution CT scans.

Shifting pneumothorax after heart-lung transplantation.

Heart-lung transplantation involves the total replacement of two of the most complex organs of the thoracic cavity. This procedure is usually reserved for patients with failure of both systems, such as in primary pulmonary hypertension or chronic Eisenmenger physiology. The en bloc replacement of the heart and lungs leaves an open communication between the two sides of the thorax that may allow air or fluid to shift from one side to the other.

Preoperative assessment of prostatic carcinoma by computerized tomography. Weaknesses and new perspectives.

A retrospective study of five years' experience with fourth-generation computerized tomography (CT) scan was undertaken to assess the frequency of understaging in prostate cancer. A total of 160 patients with preoperative scans were surgically staged. In 10 patients, the operation was aborted after pelvic node dissection had revealed unsuspected metastatic involvement.

Pneumothorax after lung biopsy: prevention with transpleural placement of compressed collagen foam plugs.

The effectiveness of pleural sealing with a compressed collagen foam plug in preventing the development of pneumothorax was evaluated in a prospective, comparative study of 50 patients undergoing transthoracic needle biopsies. The 4-cm-long plug was deposited through the thin-walled guidance needle at the end of the procedure in a position where it would cross both the visceral and the parietal pleura. The prevalence of postbiopsy pneumothorax was 28% (seven of 25 patients) in the control group and 8% (two of 25 patients) in the plug group.

Postmortem angiography of catheter-induced pulmonary artery perforation.

A case of pulmonary artery perforation by the placement of a balloon-tipped, flow-directed (Swan-Ganz) catheter, as demonstrated postmortem by angiography and confirmed by conventional autopsy method, is reported. Angiography is an effective adjunctive modality in the postmortem diagnosis and localization of pulmonary artery perforation. In cases of suspected catheter-induced pulmonary artery perforation and death, postmortem angiography may prove useful to the forensic pathologist.

Liver transplant rejection and cholestasis: comparison of technetium 99m-diisopropyl iminodiacetic acid hepatobiliary imaging with liver biopsy.

To determine whether the scintigraphic evaluation of technetium-99m diisopropyl iminodiacetic acid (DISIDA) uptake and excretion can distinguish among liver transplant patients with biopsy evidence for rejection, cholestasis or neither condition, we reviewed scintigrams and biopsies in 36 patients. There were 76 scintigrams with corresponding biopsies. Uptake and excretion were graded from image data on scales reflecting normal through severely abnormal values.

[Intravascular echography in interventional vascular radiology].

Intravascular US studies were performed with a 20 MHz rotating transducer mounted on a long flexible shaft in 14 patients undergoing interventional vascular procedures--i.e. percutaneous transluminal angioplasty (PTA), atherectomy with a Simpson device, and Palmaz stent placement.

Correlation of technetium-99m-DISIDA hepatobiliary studies with biopsies in liver transplant patients.

We compared 76 99mTc-DISIDA hepatobiliary studies with corresponding liver biopsies in 36 liver transplant patients to determine the histopathologic abnormalities that corresponded to scintigraphic abnormalities in uptake and excretion. Uptake was judged normal if the cardiac blood pool was barely visible or invisible on the ten minute image. Excretion was judged normal if images subsequent to the 15-min image showed a subjectively normal rate of decreasing parenchymal intensity.

1990 ARRS Executive Council Award. Intravascular sonography in the detection of arteriosclerosis and evaluation of vascular interventional procedures.

The purpose of this study was to evaluate the use of intravascular sonography for the detection of arteriosclerosis and to determine the effects of vascular interventional procedures on the arterial wall. A catheter-based 20-MHz transducer was used. Forty patients were studied.

Ectopic splenomegaly in Felty's syndrome.

A 50-year-old woman with Felty's syndrome, who presented with "menopausal" symptoms, was found to have a large pelvic mass on physical exam. Computed tomography of the pelvis led to an incorrect diagnosis of malignancy, while radionuclide imaging using Tc-99m sulfur colloid confirmed the diagnosis of ectopic splenomegaly.