Non-interpretive radiology: an Irish perspective.

AIM: To describe and quantify the range of non-interpretive tasks engaged in by consultant radiologists in Ireland today. MATERIALS AND METHODS: A multiple-choice electronic survey was circulated to over 200 Irish consultant radiologists and results were analysed. RESULTS: Responses were received from approximately 40% of the 267 full-time equivalent consultants in Ireland at the time of the survey. There was a wide sub-specialty mix, and responses from both clinical directors and those without designated administrative responsibility. Overall, the three most time-consuming activities were reported to be multidisciplinary meetings, vetting, and informal consultations. Non-interpretive tasks were estimated to account for 35% of the working week, with higher figures (up to 60%) for clinical directors. CONCLUSION: Consultant radiologists in Ireland spend a significant proportion of their time engaged in non-interpretive radiology; acknowledgement and scheduling of non-interpretive tasks will need to be supported by appropriate workforce planning. Non-interpretive skills will also need to be addressed during training to adequately prepare trainees for the reality of the workplace.

Development and preliminary validation of a plate-based CB1/CB2 receptor functional assay.

Cannabinoid (CB) receptors are being targeted therapeutically for the treatment of anxiety, obesity, movement disorders, glaucoma, and pain. More recently, cannabinoid agonists have displayed antiproliferative activity against breast cancer and prostate cancer in animal models. To study cannabinoid receptor ligands, we have developed a novel plate-based assay that measures internalization of CB1/CB2 receptors by determining the change in the intracellular levels of the radiolabeled agonists: [(3)H]Win55-212-2 for CB1 and [(3)H]CP55-940 for CB2. The developed plate-based assay was validated by determining IC50 values for known antagonists: AM251, AM281, AM630, and AM6545. The data obtained were consistent with previously reported values, thereby confirming that the assay can be used to determine the functional binding activities (IC50) of antagonists for the CB1 and CB2 receptors. In addition, we demonstrated that the plate-based assay may be used for screening against complex matrices. Specifically, we demonstrated that the plate-based assay was able to identify which extracts of several species of the genus Zanthoxylum had activity at the CB1/CB2 receptors.

An HPLC method for the determination of the free cortisol/cortisone ratio in human urine.

The measurement of the urinary free cortisol-cortisone ratio has been reported to be a sensitive indicator of renal 11 beta-hydroxysteroid dehydrogenase type 2 (11 beta-HSD 2) activity. This converts biologically active cortisol to inactive cortisone. A decrease in its activity (e.g. through disease or inhibition caused by a therapeutic agent or a foodstuff) may increase cortisol levels and susceptibility towards hypertension. The method presented here uses a simple isocratic tandem column HPLC system. The method has been validated and found to be robust and reproducible. The lower limit of quantification (LLOQ) was found to be 10 ng/mL for both cortisol and cortisone. Samples of urine (n = 99) from patients, most of whom were on complex combinations of drugs, were analyzed and 92% of samples were found to give successful results with this method (cortisol and cortisone above LLOQ). The ratio ranged from 0.07 to 5.61. No interferences were noted from the drugs that the patients were taking. It was also found that a morning spot urine sample gave comparable results to 24 h collection samples, thus making sample collection much easier.

The urinary excretion of gamma-hydroxybutyric acid in man.

gamma-Hydroxybutyric acid (GHB) has been widely associated with drug-facilitated sexual assault (DFSA). However, its excretion profile in man has not been well characterized. To assess the detectability of GHB for forensic cases and to correlate urinary levels with dose, we have examined the excretion profiles of 1- and 2-g doses of GHB (sodium salt) in a healthy male volunteer. The urinary levels were measured by a novel, simple and highly reproducible method. The drug was found to be excreted in small amounts in the free form (0.86 and 1.16% for 1- and 2-g doses, respectively) rapidly in urine (< or = 10 h). The urinary levels were found to be in the low mg L(-1) range (up to 29.1 mg L(-1)). The work presented demonstrates that it is of the utmost importance to collect the samples as soon as possible following the alleged assault.

Scintigraphic and MR perfusion imaging in preoperative evaluation for lung volume reduction surgery: pilot study results.

PURPOSE: To compare MR perfusion imaging with perfusion scintigraphy in the evaluation of patients with pulmonary emphysema being considered for lung volume reduction surgery. PATIENTS AND METHODS: Six patients with pulmonary emphysema and two normal individuals were evaluated by MR perfusion imaging, perfusion scintigraphy, and selective bilateral pulmonary angiography. MR images were obtained with an enhanced fast gradient recalled echo with three-dimensional Fourier transformation technique (efgre 3D) (6.3/1.3; flip angle, 30 degrees; field of view, 45-48 cm; matrix, 256 x 160). The presence or absence of perfusion defects in each segment was evaluated by two independent observers. RESULTS: Using angiography as the gold standard, the sensitivity, specificity, and accuracy of MR perfusion imaging in detecting focal perfusion abnormalities were 90%, 87%, and 89%, respectively, while those of perfusion scintigraphy were 71%, 76%, and 71%, respectively. The diagnostic accuracy of MR perfusion imaging was significantly higher than that of scintigraphy (p<0.001, McNemar test). There was good agreement between two observers for MR perfusion imaging (kappa statistic, 0.66) and only moderate agreement for perfusion scintigraphy (kappa statistic, 0.51). CONCLUSION: MR perfusion imaging is superior to perfusion scintigraphy in the evaluation of pulmonary parenchymal perfusion in patients with pulmonary emphysema.

Massive left diaphragmatic separation and rupture due to coughing during an asthma exacerbation.

We report a case of herniation of abdominal contents into the left hemithorax in a patient hospitalized with an acute exacerbation of asthma accompanied by paroxysms of coughing. There was no history of trauma. We believe this is the first reported case of diaphragmatic rupture complicating an asthma exacerbation. We review clinical features, pathophysiology, diagnosis, and treatment of diaphragmatic rupture in its most common setting, trauma, and discuss its occasional "spontaneous" occurrence.

A sensitive immunoassay for flunitrazepam and metabolites.

The objective of this study was to develop an immunoassay that would be capable of detecting flunitrazepam and/or cross-reacting metabolites in urine and comparing the results with those obtained by gas chromatography-mass spectrometry. Doses of Rohypnol varying between 0.5 and 4 mg were given to volunteers, and urine was collected for up to two weeks postingestion. These samples were analyzed by an ELISA that was developed using an antibody raised to flunitrazepam and a drug-enzyme conjugate prepared by attaching 7-aminoflunitrazepam to horseradish peroxidase. Significant levels of flunitrazepam and/or cross-reacting metabolites were detected in urine for up to one week after ingestion. The immunoassay is selective with only diazepam cross-reacting at a level of 1000 microg/L.

The detection and quantitation of 7-aminoflunitrazepam, the major urinary metabolite of flunitrazepam, by gas chromatography/mass spectrometry.

A sensitive gas chromatography/mass spectrometry method for the detection and quantitation of 7-aminoflunitrazepam, the major urinary metabolite of flunitrazepam, is described. The method is based upon solvent extraction followed by derivatisation with methyl-bis-trifluoroacetamide (MBTFA), to give a trifluoroacetyl derivative. A profile of 7-aminoflunitrazepam urinary concentrations following ingestion of 0.5 to 4 mg oral doses is reported. The method has been found to be reproducible and can be used for the confirmation of flunitrazepam administration.

Bronchiectasis: accuracy of high-resolution CT in the differentiation of specific diseases.

OBJECTIVE: The aim of the study was to determine whether various causes of bronchiectasis can be differentiated by the pattern and distribution of abnormalities seen on high-resolution CT. MATERIALS AND METHODS: The retrospective study included 82 consecutive patients who had a specific diagnosis of bronchiectasis proven by appropriate clinical and laboratory criteria. All patients underwent high-resolution CT scanning (1- to 1.5-mm collimation). The CT scans were assessed for the presence, extent, type, and anatomic distribution of bronchiectasis by two independent observers who were not aware of the clinical data. The observers recorded their most likely diagnosis and the degree of confidence in that diagnosis. RESULTS: The two independent observers made a correct diagnosis in 61% of cases (100/164 interpretations). On average, a correct diagnosis was made in 19 (68%) of 28 cases of cystic fibrosis, 16 (67%) of 24 cases of previous tuberculosis, six (43%) of 14 cases of previous childhood infection, five (56%) of nine cases of allergic bronchopulmonary aspergillosis, and four (57%) of seven cases of other causes of bronchiectasis. We found moderate agreement between the observers for the correct diagnosis (kappa = .53) and good agreement for the presence or absence of bronchiectasis in each lobe (kappa = .71). CONCLUSION: The pattern and distribution of abnormalities revealed by high-resolution CT in patients with bronchiectasis are influenced by the underlying cause. Bilateral, predominantly upper lobe, bronchiectasis is seen most commonly in patients with cystic fibrosis and allergic bronchopulmonary aspergillosis, unilateral upper lobe predominance in patients with tuberculosis, and lower lobe predominance in patients after childhood viral infection.

Thoracic foreign bodies in adults.

AIM: The aim of this pictorial essay is to illustrate a range of imaging manifestations of thoracic foreign bodies. METHODS AND RESULTS: The essay includes documented intrathoracic foreign bodies introduced by inhalation, aspiration, penetrating trauma or ingestion. Imaging modalities include chest radiography and computed tomography (CT). CONCLUSIONS: The majority of foreign bodies are seen on the plain chest radiograph. CT is helpful in demonstrating the presence of radiolucent foreign bodies and determining the exact location of the foreign bodies within the airways or lung parenchyma.

Idiopathic interstitial pneumonias: diagnostic accuracy of thin-section CT in 129 patients.

PURPOSE: To determine whether idiopathic interstitial pneumonias can be differentiated on the basis of the pattern and distribution of abnormalities at thin-section computed tomography (CT). MATERIALS AND METHODS: Thin-section CT scans in 129 patients with histologically proved idiopathic interstitial pneumonia (35 with usual interstitial pneumonia [UIP], 24 with bronchiolitis obliterans organizing pneumonia [BOOP], 23 with desquamative interstitial pneumonia [DIP], 20 with acute interstitial pneumonia [AIP], and 27 with nonspecific interstitial pneumonia and fibrosis [NIPF]) were independently assessed by two observers without knowledge of clinical or histologic data. The observers recorded the abnormalities, diagnosis, and degree of confidence in their diagnosis. Differential diagnosis was limited to the five types of idiopathic interstitial pneumonia. RESULTS: The two observers made a correct diagnosis, on average, in 74 (57%) cases. On average, the correct diagnosis was made in 25 (71%) cases of UIP, 19 (79%) of BOOP, 14.5 (63%) of DIP, 13 (65%) of AIP, and 2.5 (9%) of NIPF. The two observers made a correct diagnosis with a high degree of confidence in 50 (39%) readings. There was moderate agreement between the observers for the correct diagnosis (k = 0.55) and for the correct diagnosis with a high degree of confidence (k = 0.65). CONCLUSION: Except for NIPF, the various subtypes of idiopathic interstitial pneumonias often have a characteristic appearance that allows differentiation at thin-section CT.

Simple preparation of the major urinary metabolites of flunitrazepam and nitrazepam.

An alarming increase in the misuse/abuse of nitrobenzodiazepine derivatives, especially flunitrazepam, prompted us to establish reliable analytical protocols for their routine detection. Whilst the parent drugs are readily available from a number of commercial sources, it was found difficult to obtain samples of the corresponding amino metabolites which were required as analytical standards. This lead us to develop the straightforward synthetic protocol described here, to convert the readily available parent drugs, namely flunitrazepam and nitrazepam, to their respective 7-amino derivatives. The method requires minimum laboratory facilities. It involves the reduction of the nitro functionality in the parent drug to an amino group using tin (II) chloride under mild conditions, using ultrasonication at room temperature. The method is simple and should give toxicology laboratories better access to these much needed compounds.

A comparison of five commercial immunoassays for the detection of flunitrazepam and other benzodiazepines in urine.

Five commercially available immunoassay test kits (SYVA EMIT(R) d.a.u(TM), SYVA EMIT(R) II assay, Abbott FPIA, Cozart Auto-Lyte(R) and Roche Abuscreen(R) Online(TM), all used for the benzodiazepine group of drugs) were evaluated for their ability to detect flunitrazepam, its major urinary metabolite, 7-aminoflunitrazepam, and several other benzodiazepines at serial dilutions (final concentration 25-1000 ng/ml) in drug-free urine and in urines following oral administration of flunitrazepam (1-3 mg). For comparison, gas chromatography/mass spectrometry was used to measure urinary levels of 7-aminoflunitrazepam. Levels of drug detected in the study were compared with the cross-reactivities presented by the manufacturers for each individual kit. One to three mg doses of flunitrazepam were taken by volunteers and levels excreted in urine analysed over several hours. A positive response was obtained in several samples from volunteers who had taken 2 mg or 3 mg doses, but not a 1 mg dose. Thirty-five clinical samples from the individuals suspected of benzodiazepine abuse were also examined. The results were not consistent among the kits evaluated.We conclude that the test kits evaluated in this study do not detect flunitrazepam reliably, due primarily to their poor sensitivities.

Interventional radiology of the biliary tract.

Interventional radiology provides a range of management options applicable to a broad spectrum of patients with biliary tract disorders. This review highlights the importance of these procedures, and illustrates their safety and effectiveness. Percutaneous transcatheter decompression has a well-established role in the management of patients with benign and malignant biliary obstruction. The advent of metallic stents has greatly increased the value of these techniques. Patients with biliary tract calculi can be successfully treated with a variety of percutaneous techniques, obviating surgery and providing a useful alternative to endoscopic methods. Finally, percutaneous cholecystostomy has evolved as a valuable adjunct in the treatment of calculous cholecystitis, as well as providing the definitive cure for many patients with acalculous cholecystitis.