Depth-focused radio frequency coils for MR imaging

Surface coils improve signal-to-noise ratios by the simple expedient of reducing field of view. The uniformity of response of these coils is poor, since signal reception is weighted toward the surface of the object, which generally is of least interest. Furthermore, whole-section transmitter coils excite the subject uniformly, so that weak signals are detected from far regions. A dual-coil arrangement permits avoidance of these problems by combining the nonuniform excitation and reception characteristics of two surface coils.     

Indwelling ureteral stents: percutaneous management of complications

Complications of indwelling ureteral stents were managed percutaneously in 13 patients. These complications consisted of three fractured, three heavily encrusted, and seven migrated stents. While most ureteral stent malfunctions are routinely managed with retrograde techniques, the percutaneous approach allows effective clinical management in selected cases in which extensive renal stone material or brittle intrarenal stent fragments are present or when previous surgery or ureteral strictures do not permit a retrograde approach. Fluoroscopically guided removal of migrated stents and percutaneous endoscopic techniques, for complex cases such as those requiring stone removal, were successful and without complications.     

MR imaging of the acutely injured patient with cervical traction

Magnetic resonance (MR) imaging of the patient with acute cervical injury is important because of the potential prognostic significance of the appearance of the spinal cord at the time of injury. However, cervical traction may involve equipment incompatible with the magnetic environment, and transferring the patient to the imaging table may make it difficult to maintain traction. The authors describe a simple, inexpensive, and reliable method for providing cervical traction within the magnet room.     

Acne-associated spondylarthropathy: radiographic features

Experience with six patients with severe acne and associated axial and peripheral arthritis is described. Four of the patients had a dermatologic triad of severe acne, hidradenitis suppurativa, and dissecting cellulitis of the scalp, the so-called follicular occlusion triad. All were black men with episodic peripheral arthropathy and low back pain. One had inflammatory bowel disease. Rheumatoid factor and HLA-B27 were absent in five patients who had these determinations. An erosive and proliferative arthritis of the axial and appendicular skeleton is described. The radiographic findings were indistinguishable from those of the seronegative spondylarthropathies. We found no previous reports in the radiologic literature describing this articulocutaneous entity.     

Evaluation of the biliary tract: The value of performing magnetic resonance cholangiopancreatography in conjunction with a 3‐D spoiled gradient‐echo gadolinium enhanced dynamic sequence

The 3‐D gradient‐echo (GRE) sequence allows thinner sections and better resolution of biliary obstruction. When the presence of biliary obstruction is identified using magnetic resonance cholangiopancreatography, the addition of the 3‐D GRE sequence may be helpful for diagnosing biliary obstruction. By showing the changes in the bile duct wall, within the duct lumen and around the bile duct, this technique can be helpful for distinguishing benign from malignant stricture as well as a stone from an enhancing intraluminal mass.     

腹膜透析86例护理体会

1临床资料本组患者86例,年龄40~74(平均56)岁,急性肾功能衰竭15例,慢性肾功能衰竭62例,严重的水电解质紊乱、酸碱失衡和不宜行血液透析9例,行腹膜透析2mo4a.     

Clinical utility of fluoride-18 positron emission tomography/CT in temporomandibular disorder with osteoarthritis: comparisons with 99mTc-MDP bone scan

Objectives:

The purpose of this study was to compare the clinical utility of fluoride-18 positron emission tomography (¹⁸F-PET)/CT with that of conventional ^99mTc-methylene diphosphonate (MDP) bone scan in temporomandibular disorder (TMD) with osteoarthritis.

Methods:

24 patients with TMD who underwent both ¹⁸F-PET/CT and ^99mTc-MDP bone scans for diagnostic work-up were enrolled. The temporomandibular joint (TMJ)-to-skull uptake ratio, TMJ-to-muscle uptake ratio and TMJ-to-spine uptake ratio on ¹⁸F-PET/CT and the TMJ uptake ratio on bone scan were measured.

Results:

Of the 48 TMJs in 24 patients, 35 TMJs were diagnosed as TMD with osteoarthritis, 8 TMJs as TMD with anterior disc displacement (ADD), and the remaining 5 TMJs showed no evidence of TMD (NED). All three uptake ratios on ¹⁸F-PET/CT and the TMJ uptake ratio on the bone scan tended to be higher in TMD with osteoarthritis than in TMD with ADD or NED. Receiver operating characteristic (ROC) curve analysis for detecting TMD with osteoarthritis indicated that the TMJ-to-skull uptake ratio, TMJ-to-muscle uptake ratio and TMJ-to-spine uptake ratio on PET/CT (0.819, 0.771 and 0.813, respectively) showed higher area under the ROC curve value than the TMJ ratio on bone scan (0.714). The TMJ-to-skull uptake ratio on PET/CT showed the highest sensitivity (89%) and accuracy (81%) of all uptake ratios.

Conclusions:

¹⁸F-PET/CT can help diagnose TMD with osteoarthritis with superior diagnostic ability and is a suitable alternative modality to a conventional ^99mTc-MDP bone scan.