Dural ectasia in Marfan syndrome: a case control study.

BACKGROUND AND PURPOSE: Dural ectasia (DE) is one of the major criteria of Marfan syndrome (MFS). Our aim was to establish the prevalence of DE in an adult population fulfilling the Ghent criteria for MFS and to assess definitions of DE. MATERIALS AND METHODS: One hundred five adults with suspected MFS were included. MR imaging at 1.5T was performed unless contraindicated; then CT was obtained. Lumbosacral anteroposterior vertebral body diameters (VBD) and dural sac diameters (DSD) were measured. Dural sac ratios (DSR = DSD/VBD) at levels L3 through S1 were calculated. Anterior meningoceles, herniations of nerve root sleeves, and scalloping were characterized. One hundred one sex- and age-matched patients were included as controls. RESULTS: We identified 3 patient groups: 1) fulfilling Ghent criteria independent of DE (n = 73), 2); fulfilling Ghent criteria dependent on DE (n = 14), and 3); and suspected MFS, not fulfilling Ghent criteria (n = 18). DE was found in 86% of group 1. At levels L4-S1, mean DSRs were significantly higher in group 1 than in group 3 and controls (P < .001). Herniations of the nerve root sleeves were present in 73% in group 1 versus 1% in controls. Anterior meningoceles were found in 37% and 14% in groups 1 and 2, respectively, but not in group 3 or controls. CONCLUSIONS: The diagnosis of DE on MR imaging or CT should be based on the presence of at least 1 of the following criteria: anterior meningoceles or nerve root sleeve herniation, DSD at S1 or below larger than DSD at L4, and DSR at S1 >0.59.

A magnetic resonance imaging study of modifications to the infraclavicular brachial plexus block.

A previously described infraclavicular brachial plexus block may be modified by using a more lateral needle insertion point, while the patient abducts the arm 45 degrees or 90 degrees. In performing the modified block on patients abducting 45 degrees, we often had problems finding the cords of the brachial plexus. Therefore, we designed an anatomic study to describe the ability of the recommended needle direction to consistently reach the cords. Additionally, we assessed the risk of penetrating the pleura by the needle. Magnetic resonance images were obtained in 10 volunteers. From these images, a virtual reality model of each volunteer was created, allowing precise positioning of a simulated needle according to the modified block, without exposing the volunteers to actual needle placement. In both arm positions, the recommended needle angle of 45 degrees to the skin was too shallow to reach a defined target on the cords. Comparing the two arm positions, target precision and risk of contacting the pleura were more favorable with the greater arm abduction. We conclude that when the arm is abducted to 90 degrees, a 65 degrees -needle angle to the skin appears optimal for contacting the cords, still with a minimal risk of penetrating the pleura. However, this needs to be confirmed by a clinical study.

Magnetic resonance imaging demonstrates lack of precision in needle placement by the infraclavicular brachial plexus block described by Raj et al.

UNLABELLED: The infraclavicular brachial plexus block first described by Raj et al. was supposed to anesthetize all the main peripheral nerves of the brachial plexus without the risk of pneumothorax. However, in performing the block, we have had difficulties finding the nerves at the cord level. Therefore, we questioned whether the recommended needle direction (the "Raj line") guides the needle close enough to the cords. We therefore designed an anatomic study to answer this question and to assess the risks of entering the pleura and axillary vein. Ten volunteers were examined noninvasively in an open model magnetic resonance scanner. The Raj line deviated greatly from a defined location on the cords by a mean of 26 (range 14-39) mm, always caudad, and posterior to the target in nine cases. Further, the needle trajectory's shortest distance to the pleura was only 10 (0-27) mm, and in one case, it hit the pleura. Finally, the Raj line's distance to the axillary vein was also short, 11 (0-18) mm. We conclude that a modification of the method is necessary to guide the needle closer to the cords and further away from the pleura and the axillary vein. A more lateral needle insertion seems beneficial. IMPLICATIONS: Using a magnetic resonance scanner, the anatomical basis of Raj's infraclavicular method for brachial plexus blockade was examined in volunteers. The results show that the method should be modified to make it more precise and to provide less risk of complications.

MR findings in cases of suspected impacted fracture of the femoral neck.

PURPOSE: To evaluate MR imaging of the hip in patients with a clinically suspected impacted fracture of the femoral neck in cases where conventional plain films show negative or equivocal findings. MATERIAL AND METHODS: Twenty-seven such patients were prospectively examined by MR imaging with a 1.0 T unit, within 24 hours of admittance to hospital. A coronal T1-weighted turbo spin-echo sequence (n = 27), and a coronal STIR sequence (n = 25) or a coronal T2-weighted turbo spin-echo fat saturation sequence (n = 2) were used. The evaluations were made by 2 radiologists with experience in musculoskeletal radiology. RESULTS: There were 6 patients with a pertrochanteric fracture, 2 without and 4 with slight displacement. Five patients had an impacted fracture of the femoral neck, and 3 had a fracture of the superior pubic bone. Of 2 patients with advanced arthrosis, 1 had an impacted femoral neck fracture and the other a nondisplaced intertrochanteric fracture. There was 1 patient who had sustained a nondisplaced acetabular fracture with increased joint fluid and muscle contusions. Three patients had muscle contusions only. Two patients had bone marrow contusions only, while 2 others with advanced coxarthrosis had increased joint fluid only. Three patients showed normal findings. Our findings led to emergency surgery in 13 cases, and conservative measures directed to the specific MR findings in 14 patients. CONCLUSION: MR imaging should be the first modality of choice in examining patients with a clinically suspected impacted fracture of the femoral neck where conventional films show negative or equivocal findings.

[Percutaneous automated lumbar nucleotomy. Patient selection, practical performance and clinical results]. / Perkutan automatisert lumbal nukleotomi. Pasientutvelgelse, praktisk utførelse og kliniske resultater.

Percutaneous nucleotomy is designed to treat small and medium-sized contained disk hernias. It is offered to patients who have not responded to conservative treatment for three months or more. The nucleotomy procedure is well tolerated by a majority of patients and the rate of complications is low. The patients can be treated as out-patients. Among a total material of 130 patients, a primary good response to the treatment was observed in 81 (62%). However, owing to recurrencies the success rate had fallen to 52% at 12-39 months (mean 22 months) after nucleotomy. In selected patients with symptoms from one disk level only, and with no evidence of spinal stenosis, or of osteophyte formation or a narrowing of the disk space by more than 25%, the results were better. Here the success rate was 61% (70% in males and 50% in females).

Clinical applications of computerized fluoroscopy: the extracranial carotid arteries.

Preliminary results obtained with a new computerized fluoroscopic apparatus in examination of the extracranial carotid arteries are described. All patients had clinical signs of symptoms of extracranial occlusive vascular disease. In most cases, image quality was sufficient to display patency of the internal carotid arteries, with excellent correlation between intravenous and conventional angiography. While the new technique is not totally noninvasive, it does eliminate many of the risks and costs of conventional arteriography.

Arthrography of the knee joint with amipaque.

In a double-blind investigation, 30 knee arthrographies were performed by injection of either Amipaque 290 mg I/ml or Urografin 60% (292 mg I/ml). Both contrast media are well tolerated, and give excellent initial contrast quality, which deteriorates rapidly. This occurs more slowly with Amipaque, which has lower osmolality and causes less joint effusion.