Biomedical subjects
Publications and source records attributed to P Magotteaux.
Stepping-table MR angiography of the upper limb arteries is reported in a patient with clinical and sonographic signs of ischemia. Advantages and limitations of the technique are discussed.
Our objective was to assess how far the progress in ultrasound devices has increased feasibility and accuracy of Duplex ultrasound (DUS) for the diagnosis of renal artery stenosis (RAS), in a population with high prevalence of atherosclerotic renovascular lesions. Ninety-one hypertensive patients with atherosclerotic disease were prospectively evaluated by both DUS and digital subtraction angiography (DSA) of the renal arteries. Only proximal criteria (peak systolic velocity >180 mm/s or renal-to-aortic ratio >3.5) were used for the diagnosis of significant RAS (>60% narrowing). For both techniques, two readers were involved for interobserver variability study. Two hundred one arteries were demonstrated by DSA on 182 available kidneys. The prevalence of RAS among the study group was 37%. Sixteen of the 19 accessory arteries were not seen at DUS; in 8 patients, one renal artery was not seen at DUS (feasibility 91%). On the 177 arteries assessed, in comparison with DSA, DUS yielded 96, 91, and 97% mean values of accuracy, sensitivity, and specificity, respectively. Kappa for interobserver agreement was 0.95 for DUS and 0.92 for DSA. Although still unreliable for the detection of accessory arteries, DUS is in our experience an accurate and reproducible diagnostic test for RAS.
In our institution, MRCP is actually replacing diagnostic ERCP. This study is addressing its accuracy in the diagnosis of symptomatic choledocholithiasis. 137 MRCP were performed in patients with upper abdominal pain and biological anomalies (n = 48), pain with cholelithiasis at sonography (n = 69) or non-alcoholic acute pancreatitis (n = 20) on a 1.5 T system with high gradients using a standardized combination of breath-hold HASTE and RARE sequences. We included in our study 74 patients who underwent as second test ERCP (n = 36), peroperative cholangiography (n = 13), or extensive follow-up with laboratory tests and/or sonography (n = 25). All examinations were judged as diagnostic, discrepancies between direct cholangiography and MRCP being noted in 4 patients (5.4%). Lithiasis was misinterpreted on MRCP as bubbles in 2 patients after sphincterotomy or surgery. We had two false positive diagnoses on MRCP: in one patient peroperative cholangiography was negative and in the other one ERCP was negative. With a sensitivity and PPV of 92%, a specificity and NPV of 96% MRCP in our experience is shown as an accurate diagnostic tool for the detection of stone in the common bile duct replacing ERCP.
Ultrasonography and CT-scanner remain the first choice nowadays concerning detection and preoperative work-up of pancreatic cancer. MRI offers interesting options for the detection of liver metastases, and high quality of ductal and vascular examination. Actually, while we await a larger diffusion of MR systems and radiological expertise this technique is preferentially indicated as a third-step procedure when ultrasonography and CT-scanner are normal despite a real suspicion. Otherwise, MRI permits with a single non-invasive examination a complete work-up useful to prepare palliative therapy in case of unresectable tumor.
Duplex examination is presently established as a safe non-invasive and accurate method of evaluating patients with extracranial cerebrovascular disease which usually provides complete information about the extent of carotid artery narrowing Arteriography, in this indication, is an invasive procedure with a total complication rate of 3-4% with 1% of permanent stroke. If it is currently accepted that in emergency conditions (ictus ingravescens, pre-occlusive plaque) or if iodinated contrast media are contraindicated, thrombendarteriectomy can be performed without arteriography it could be extended to most cases. The authors stress the criteria to increase the number of those patients, summarize the pre-requisites to achieve this goal, and comment on the future alternative position of MRA.
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There are three milestones in the history of thoracic radiology. Thoracic radiology started in 1897 when Williams developed thoracic fluoroscopy and introduced the basic concepts of roentgenologic interpretation. At the same time, the first chest films were performed allowing decisive improvement in the diagnosis of many chest diseases. Continuous technical improvement is responsible for the fact that, even today, the conventional chest film remains a highly accurate and frequently used imaging modality. A third milestone was the development of digital radiography and its use in the chest. Computerised tomography changed thoracic imaging dramatically; in a first step mainly as a tool to visualise soft tissue abnormalities and, later on, also as a modality to study lung disease. The recent development of the digital chest radiograph has again added new perspectives to the approach and diagnosis of chest disease.
One hundred and twenty-one peritoneal, retroperitoneal and pelvic abscesses were treated percutaneously using CT or US guidance. The lesions developed after abdominal surgery. Sixty-three abscesses (52%) were situated in the peritoneal cavity, 31 (26%) in the retroperitoneal cavity and 27 (22%) in the pelvis. A definitive treatment was obtained in 74% of peritoneal abscesses, 67% of retroperitoneal abscesses and 82% of pelvic abscesses. Failure most commonly occurred with multiloculated lesions or lesions associated with fistulous communication. There was a low rate of complication (1%). percutaneous drainage avoids the risks inherent in surgery and anesthesia, saves considerable time and meets greater patient acceptance. If a total cure is not systematic, a beneficial temporizing effect may however be obtained by percutaneous drainage. This procedure should be indicated for the initial treatment of postsurgical abscesses.
Thromboendarterectomy is sometimes performed in association with coronary artery bypass graft surgery (CABG). Right coronary arteries and severely narrowed coronary arteries mainly undergo thromboendarterectomy, but perioperative acute myocardial infarctions (AMI) are possible complications. One hundred seventy-six consecutive patients with rest and stress thallium-201 scintigraphy and angiography were studied before and after surgery. To compare patients with and without thromboendarterectomy, 48 patients who had undergone thromboendarterectomy and whose characteristics matched closely those of patients who had not were selected. Twenty patients had previous AMI before CABG in each group. Analysis accounted for the severity of vessel lesion (complete or incomplete) and for the patency of the graft and of the native coronary artery. In these 96 patients, graft patency was lower than in the overall group and similar among patients with and without thromboendarterectomy among the 56 patients without previous AMI. In patients with previous AMI and thromboendarterectomy, however, reperfusion was achieved more often through the native vessel than through the graft. New AMI or residual ischemia occurred in 32% of the areas undergoing thromboendarterectomy and in only 5% of the standard grafts (p less than 0.001). Best results were obtained in patients with incomplete occlusion after AMI. Patients without previous AMI had worse results. Thus, thromboendarterectomy can yield 64 to 75% good results in selected subgroups when CABG is otherwise impossible, but should be avoided in mildly or moderately stenotic arteries perfusing noninfarcted myocardium.
The efficacy of coronary bypass grafting obviously being linked to graft patency, it is compulsory to look for any innovation that could improve the patency rate. Ticlopidine, an antiplatelet drug, was tested against placebo in a double-blind trial: 173 patients (475 grafts) subjected to venous coronary artery bypass grafting were randomly treated with ticlopidine (250 mg twice daily) or placebo from the second postoperative day for 12 months. Graft patency was assessed by digital angiography on days 10 (99.4% of the patients), 180 (98.2%), and 360 (91.7%). The effect of treatment on platelet aggregation and bleeding time were measured concomitantly; a clear-cut effect was demonstrated at each interval. Intention-to-treat graft-by-graft analysis shows that ticlopidine significantly reduced the graft occlusion rate on day 10 (7.1% versus 13.4%, p less than 0.05), day 180 (15.0% versus 24.0%, p less than 0.02), and day 360 (15.9% versus 26.1%, p less than 0.01). Sequential grafts to the left anterior descending coronary artery, with side-to-side anastomosis to diagonal branch(es), are less frequently occluded than individual grafts. On the contrary, grafts to endarterectomized vessels occlude more frequently. Individual patient-by-patient analysis shows that patency of all grafts at each study time, is more frequent in the ticlopidine group. The difference is significant when one considers patients without sequential or endarterectomized grafts. The difference is also present at each study time: day 10 (84.4% versus 66.7%, p less than 0.05), day 180 (74.4% versus 52.3%, p less than 0.05) and day 360 (75.0% versus 52.5%, p less than 0.05). Results are even more impressive if one excludes from analysis the four patients in the ticlopidine group in whom administration of the drug was delayed. This supports previous suggestions that early therapy is necessary. These results show that graft occlusion occurs mainly in the first 6 postoperative months. The incidence of occlusion is significantly reduced by ticlopidine therapy.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.