Knee in early juvenile rheumatoid arthritis: MR imaging findings.

Purpose: To determine the magnetic resonance (MR) imaging findings in the knee in early juvenile rheumatoid arthritis.

Materials And Methods: MR imaging (1.5 T) was performed in the more symptomatic knee in 30 children with juvenile rheumatoid arthritis with a symptom duration 1 year or less.

Minimizing radiation dose for pediatric body applications of single-detector helical CT: strategies at a large Children's Hospital.

Adjustments of the standard helical CT protocols for adults can result in reduced radiation dose when imaging children. It is the radiologist's responsibility to critically evaluate the CT techniques used at their institution. Adjustments to CT protocols should be made to choose the appropriate mA and pitch when imaging children.

Magnetic resonance imaging of the dysplastic renal moiety and ectopic ureter.

Purpose: We determined the role of magnetic resonance imaging (MRI) in symptomatic children with clinically suspected and radiologically occult dysplastic renal moieties and ectopic ureters.

Materials And Methods: We reviewed clinical, imaging, cystoscopic, surgical and histological findings in 6 symptomatic children 1 to 15 years old with dysplastic renal moieties.

Results: After multiple conventional imaging studies failed to delineate urinary tract anatomy MRI provided detailed multiplanar images of dysplastic renal moieties that were diagnostic and predictive of subsequent intraoperative findings.

Cyclic cystography: diagnostic yield in selected pediatric populations.

Purpose: To test the hypothesis that the diagnostic yield of cyclic cystography is related to the prevalence of vesicoureteral reflux (VUR) in the population being evaluated.

Materials And Methods: Two groups of children were examined prospectively: 124 with severe urinary tract infection, defined as patient hospitalization or a maximum temperature greater than 39.5 degrees C, and 135 with previously diagnosed VUR.

MR imaging of pediatric musculoskeletal inflammatory and infectious disorders.

Inflammatory and infectious disorders of the skeletally immature extraspinal musculoskeletal system affect the bones, contiguous soft tissues, muscles, and joints. MR imaging of osteomyelitis, soft tissue infection, inflammatory muscle disease, and acute and chronic joint disease are discussed in the context of underlying pathophysiology. Discussion includes imaging optimization, contribution of MR imaging to overall patient management, and differential diagnostic considerations for the pediatric patient.

Magnetic resonance imaging in juvenile rheumatoid arthritis.

Objectives: This study was undertaken to examine the role of magnetic resonance imaging (MRI) in the management of patients with juvenile rheumatoid arthritis (JRA).

Methods: A Medline search was performed to identify all publications pertaining to MRI in JRA. Further searches and identification of articles from bibliographies identified articles pertaining to plain radiograph imaging in JRA and MRI in adult rheumatoid arthritis.

Unilateral vesicoureteral reflux: association with protected renal function in patients with posterior urethral valves.

Objective: The prognosis in patients with posterior urethral valves (PUV) is related to the degree of renal insufficiency. Urinary ascites or urinoma, congenital bladder diverticula, or severe unilateral vesicoureteral reflux has been associated with protected renal function. We present clinical and imaging findings in eight patients with PUV and unilateral reflux who have preserved renal function.

Wilms tumor and nephroblastomatosis: imaging characteristics at gadolinium-enhanced MR imaging.

Twelve children with Wilms tumors were prospectively evaluated with 1.5-T magnetic resonance (MR) imaging. Spin-echo images were obtained before and after administration of gadopentetate dimeglumine.

The effect of intra-articular gadolinium-DTPA on synovial membrane and cartilage.

This investigation evaluated the potential effect of gadolinium (Gd)-DTPA-dimeglumine on synovial membrane and joint cartilage, using macroscopic, microscopic, and x-ray fluorescent spectroscopic techniques. Thirteen New Zealand white rabbits (26 knees) were used in this study, ten receiving 500 micromolar injections of Gd-DTPA-dimeglumine in their right knees; the remainder of the knees served as controls. One injected knee had minimal joint effusion and one had mild hyperemia.

Carpal tunnel syndrome: morphologic changes after release of the transverse carpal ligament.

We describe the morphologic changes that follow division of the transverse carpal ligament in patients with carpal tunnel syndrome. Fifteen hands in 12 patients with carpal tunnel syndrome were studied with magnetic resonance imaging before operation and for 6 weeks after operation. Eight hands were studied at 8 months after operation.

Detection of testicular torsion by magnetic resonance imaging in a rat model.

Testicular torsion is one of the most common pediatric urological emergencies. Incorrect or delayed diagnosis contributes significantly to morbidity. We previously have shown that magnetic resonance displays scrotal contents with great detail using hydrogen concentration weighted and T2 weighted images.

A wire-sheath system for MR-guided biopsy and drainage: laboratory studies and experience in 10 patients.

On the basis of laboratory experiments, we devised a wire-sheath system for MR-guided biopsy and drainage and then evaluated that system in 10 patients. The localizing system consisted of a 20-gauge plastic sheath into which a stainless-steel alloy wire had been inserted. In laboratory studies, we compared this wire-sheath assembly with other materials to determine its optimal visualization on MR images.

Inflatable surface coil for MR imaging of the prostate.

An inflatable surface coil for transrectal magnetic resonance imaging of the prostate was designed. The coil was tested during imaging of an insulated saline phantom and of the prostates of four patients. Phantom images were comparable to those obtained with commercial coils of similar size.

The high signal intensity meniscus of the knee. Magnetic resonance evaluation and in vivo correlation.

This study describes the different appearances of meniscal abnormalities on magnetic resonance (MR) images and correlates macroscopic and histologic findings. Twenty-three of 40 cadaveric menisci with MR signal abnormalities were examined macroscopically; five of the 23 were studied histologically. In addition, MR studies of seven patients (14 menisci) were examined and findings were correlated arthroscopically.

Carpal tunnel volume determination by magnetic resonance imaging three-dimensional reconstruction.

Three-dimensional computer reconstruction of magnetic resonance images (MRI) of ten cadaveric specimens was used to determine carpal tunnel volume and carpal arch width. Magnetic resonance images-acquired data were compared with direct measurement of cadaveric carpal canal volume by means of a silicone-injection technique. Mean MRI three-dimensional reconstruction volume was 5.

Localization grid for MR-guided biopsy.

A localization grid for use with magnetic resonance (MR)-guided biopsies was designed and evaluated. First, the signal intensities of various concentrations of Gd-DTPA in polyethylene tubes of different sizes and at various pulse sequences were evaluated. The optimal signal intensity on all pulse sequences was obtained with a concentration of 500 microM.

Perfluorochemicals as gastrointestinal contrast agents for MR imaging: preliminary studies in rats and humans.

The ability to distinguish bowel from other intraabdominal structures is essential for the accurate diagnosis of intraabdominal disease with MR. Because perfluorochemicals have no protons, they cause no MR signal. Since they are immiscible with water, they create a signal void in bowel independent of bowel contents and thus are suitable as oral contrast agents.

Articular cartilage defects: detectability in cadaver knees with MR.

The capability of 1.5-T MR imaging to detect focal defects in articular cartilage was investigated with cadaveric knees with and without intraarticular injection of saline and gadolinium-DTPA (Gd-DTPA). Full-thickness cartilage lesions ranging in diameter from 1 to 5 mm were surgically created in the femoral articular surfaces.

Magnetic resonance imaging of the cryptorchid testis.

Magnetic resonance imaging was used to evaluate seven patients with undescended testes. In six patients the presence or absence of testicular tissue was predicted correctly prior to surgery. Spermatic cord structures, if present, were accurately visualized in all patients.