The detection of loose bodies in the elbow: the value of MRI and CT arthrography.

Our aim was to determine the clinical value of MRI and CT arthrography in predicting the presence of loose bodies in the elbow. A series of 26 patients with mechanical symptoms in the elbow had plain radiography, MRI and CT arthrography, followed by routine arthroscopy of the elbow. The location and number of loose bodies determined by MRI and CT arthrography were recorded. Pre-operative plain radiography, MRI and CT arthrography were compared with arthroscopy. Both MRI and CT arthrography had excellent sensitivity (92% to 100%) but low to moderate specificity (15% to 77%) in identifying posteriorly-based loose bodies. Neither MRI nor CT arthrography was consistently sensitive (46% to 91%) or specific (13% to 73%) in predicting the presence or absence of loose bodies anteriorly. The overall sensitivity for the detection of loose bodies in either compartment was 88% to 100% and the specificity 20% to 70%. Pre-operative radiography had a similar sensitivity and specificity of 84% and 71%, respectively. Our results suggest that neither CT arthrography nor MRI is reliable or accurate enough to be any more effective than plain radiography alone in patients presenting with mechanical symptoms in the elbow.

Evaluation of the IITC tail cuff blood pressure recorder in the rat against intraarterial pressure according to criteria for human devices.

National standards govern the manufacture and marketing of medical devices in the United States, including those for indirect blood pressure measurement in man. There are no comparable standards for devices for recording in laboratory animals. Noninvasive tail cuff blood pressure (BP) recording in the rat is widely accepted, but beset by methodologic difficulties. Intraarterial recording is regarded as the "gold standard" but is invasive and also susceptible to methodologic error. We compared the IITC Mark 12 photoelectric/oscillometric tail cuff system (IITC Life Sciences, Woodland Hills, CA) versus simultaneous femoral intraarterial recordings in spontaneously hypertensive rats, during anesthesia and 1 to 2 days after recover (150 recordings under each condition), according to the guidelines for human data collection and analysis suggested the American National Standard for automated sphygmomanometers. Within- and between-observer disagreements in estimates made by two observers from 40 anesthetized recordings were less for intraarterial measurements than for the tail cuff method. Within-observer differences (mean +/- SD of differences [SDD]) for systolic, diastolic, and mean pressure were 0 +/- 1, 0 +/- 1, and 0 +/- 1 mm Hg for intraarterial versus -1 +/- 3, 0 +/- 8, and 0 +/- 5 mm Hg for tail cuff. Between-observer differences were 0 +/- 2, 0 +/- 1, and 6 +/- 2 mm Hg versus 5 +/- 4, 13 +/- 7, and 0 +/- 5 mm Hg, respectively. Differences between tail cuff and intraarterial methods were 16 +/- 13, -5 +/- 11, and 2 +/- 8 mm Hg in anesthetized animals and 8 +/- 14, -5 +/- 9, and 0 +/- 9 mm Hg in conscious animals (39% to 82% of differences exceeded 5 mm Hg). The upper limits of clinically acceptable disagreement in the American National Standard are: mean of 5 mm Hg, SDD of 8 mm Hg. The disagreement between tail cuff and intraarterial recordings cannot be ascribed to either method with certainty. These findings do not support the manufacturer's guarantee of tail-cuff readings within "5 mm Hg of intraarterial." Inaccuracy and unreliability of devices intended for laboratory animal use have considerable scientific, fiscal, and ethical implications. Marketing of these devices should also be governed by rigorous standards.

Nonimmune hydrops fetalis, pulmonary sequestration, and favorable neonatal outcome.

BACKGROUND: The association of pulmonary sequestration and nonimmune fetal hydrops reportedly carries a very poor prognosis for survival. We describe three newborns with good outcomes despite the diagnosis of pulmonary sequestration; two cases were associated with hydrops fetalis and one with isolated fetal ascites. CASES: Two neonates with severe hydrops fetalis had pulmonary sequestration diagnosed postnatally. A third infant presented early in gestation with marked fetal ascites that regressed spontaneously before delivery; this infant also had pulmonary sequestration. Despite severe respiratory insufficiency requiring aggressive management, all three infants survived after surgical resection of the sequestered lung mass. CONCLUSION: These cases demonstrate the difficulties associated with antenatal counseling regarding long-term prognosis for infants with nonimmune hydrops and pulmonary sequestration. With optimal care in a tertiary perinatal center, a less pessimistic outlook than previously described in the literature may be appropriate.

Ultrasound of the abdomen.

In summary, ultrasonography and its recent advances appear ideally suited to a number of conditions common in the critically ill patient and the ICU setting. Depending on the clinical situation, and, providing appropriate technical expertise is available, ultrasonography can both gather diagnostic information and, where indicated, guide therapeutic intervention.

Evaluation of Doppler ultrasonography and dynamic contrast-enhanced CT in acute and chronic renal obstruction.

The development of a reliable, minimally invasive method of distinguishing physiologically significant renal obstruction from dilation without obstruction would have important clinical implications. As it is well known that renal blood flow decreases over time in the presence of obstruction, we investigated the ability of color flow Doppler ultrasonography and dynamic contrast-enhanced CT scanning to detect changes in blood flow in unilaterally obstructed porcine kidneys. In the initial phase of this study, the effect of acute unilateral obstruction were studied in nine pigs. The resistive index (RI) was measured with Doppler ultrasonography, and renal blood flow was quantitated with dynamic CT using tracer kinetic principles and deconvolution. The RI measurements were unable to distinguish between the obstructed kidneys and their controls. Dynamic CT scanning demonstrated a greater fall in blood flow in the obstructed kidney, and this change was significantly different from baseline. The same findings were supported by radiolabelled microsphere blood-flow measurement. In the chronic portion of the study, after surgical creation of a partial ureteric obstruction, the kidneys were studied by both techniques at 1, 2, and 3 weeks. Again, RI was unable to demonstrate any difference between obstructed and unobstructed kidneys, while CT showed a progressive fall in blood flow in each successive week that was statistically significant. Dynamic contrast-enhanced CT scanning is a promising diagnostic tool that might be used to distinguish a functionally significant renal obstruction from nonobstructive dilation. Further clinical studies to validate this technique are warranted.

Malignant paraganglioma with skeletal metastases and spinal cord compression: response and palliation with chemotherapy.

Paragangliomas (carotid body tumours, chemodectomas) may arise in any area of the body where sympathetic ganglia are present, including chemoreceptors, the adrenal medulla and retroperitoneal ganglia. Increasing numbers of patients are being reported with vertebral metastases and spinal cord compression for which either decompression laminectomy or external beam radiotherapy, or both, are required. Patients with vertebral metastases may develop progression of disease after radiation therapy. There is little published information on the use of chemotherapy in this clinical situation. We report a case of metastatic paraganglioma complicated by spinal cord compression showing evidence of clinical benefit from chemotherapy after progressive disease and symptoms developed in a region previously treated by radiation therapy.

Temporary uterine artery occlusion for treatment of menorrhagia and uterine fibroids using an incisionless Doppler-guided transvaginal clamp: case report.

We report the successful treatment of a 43-year-old woman with menorrhagia and multiple uterine fibroids by temporary uterine artery occlusion. Using a Doppler-guided transvaginal clamp, her uterine arteries were non-invasively identified and occluded by mechanical compression against the cervix for 6 h. Following removal of the clamp, blood flow in the uterine arteries returned immediately. Menorrhagia symptoms were tracked with the Ruta Menorrhagia Severity Scale. Uterine and fibroid volumes were measured by analysis of magnetic resonance images. The patient's self-reported menorrhagia symptoms were significantly reduced at 6 months (70% reduction in Ruta score) and both uterine volume and fibroid volume had decreased by more than 44% at 6 months. This case report illustrates the potential applicability of a simple-to-use, non-surgical device for the treatment of menorrhagia and uterine fibroids by temporary uterine artery occlusion.

Recovery characteristics of a rigid, nonmetallic microdialysis probe for use in an electromagnetic field.

It is well known that metal objects perturb electromagnetic fields. Therefore, a conventional metal microdialysis probe cannot be used to determine the bioeffects of electromagnetic radiation. Using fused-silica tubing, we developed an inexpensive nonmetallic, rigid microdialysis probe for use in electromagnetic radiation research or during magnetic resonance imaging. This probe has a concentric tube design, with the membrane length adjustable to the size of the area to be dialyzed. The probes tested had regenerated-cellulose membranes that were 3 mm in length. This report describes how to make this probe. Average relative recovery rates at flow rates of 2.0, 1.0, and 0.5 microliters/min were 21%, 27%, and 42%, respectively. These rates were slightly lower than the 30%, 42%, and 68% obtained with the commercially available metallic CMA10 microdialysis probe with a 3 mm membrane. This may be due to the fused-silica probe and CMA10 probe being made with different types of dialysis membranes.

Substrate utilization for estrogen synthesis by human fetal membranes and decidua.

We have investigated the ability of tissue explants of human amnion, chorion, and decidua to produce estrone when incubated alone or in the presence of estrone sulfate, dehydroepiandrosterone, dehydroepiandrosterone sulfate, androstenedione, or testosterone. Amnion produced very little estrone from any substrate. Chorion utilized all substrates and decidua utilized estrone sulfate and dehydroepiandrosterone sulfate for estrone production. For both chorion and decidua, estrone sulfate was quantitatively the most important substrate. Chorionic tissues obtained after spontaneous labor produced greater levels of estrone than tissues obtained before labor (p less than 0.05). We could demonstrate no effect of cortisol, estriol, progesterone, prostaglandins, oxytocin, or dibutyryl cyclic adenosine monophosphate on estrogen production. We also measured endogenous concentrations of estrone and estradiol in fetal membranes. We found no significant difference in tissue concentrations between the two methods of delivery. There was no significant correlation between estrone and estradiol concentrations and distance from the placenta. We conclude that human chorion and decidua can produce estrogen, which may have some role in determining the timing of parturition.

Adenocarcinoma of the pancreatic ducts: comparative evaluation with CT and MR imaging at 1.5 T.

A prospective comparison of computed tomography (CT) and magnetic resonance (MR) imaging at 1.5 T was performed in 50 patients with the suspected diagnosis of pancreatic carcinoma. CT scans were obtained before and after administration of contrast material in 41 of 50 patients (82%); 34 of 41 postcontrast scans (83%) were obtained with dynamic CT. MR images were interpreted without knowledge of the results of CT, ultrasound, cholangiography, or endoscopic retrograde cholangiopancreatography in 48 patients (96%). Surgical correlation of findings at CT and MR imaging was performed in 24 patients (48%) at laparotomy and in two patients (4%) at autopsy. On T1-weighted MR images, relatively diminished signal intensity of tumor compared with that of the adjacent pancreas was a consistent finding. MR imaging proved superior to CT in identification of pancreatic carcinoma (particularly in smaller intrapancreatic tumors), peripancreatic extension, vascular and portal vein invasion, and duodenal invasion. These results suggest that MR imaging of the pancreas is superior in many instances to CT in preoperative evaluation of pancreatic carcinoma.

Effect of indomethacin plus ranitidine in advanced melanoma patients on high-dose interleukin-2.

Preclinical models of advanced melanoma have shown that chronic indomethacin therapy combined with interleukin 2 (IL-2) can eradicate experimental metastases. A phase II trial was done in patients with advanced melanoma. Indomethacin and ranitidine were begun at least one week before IL-2. Of the objective responses in 3 patients, 2 were achieved on ranitidine and indomethacin alone, before start of IL-2. Indomethacin and ranitidine may be responsible for some responses in melanoma patients previously attributed to IL-2.

Implications of unsuspected pulmonary embolism detected by computed tomography.

OBJECTIVE: To describe the computed tomography (CT) findings and clinical implications of pulmonary thromboembolism noted incidentally on CT. PATIENTS AND METHODS: The authors reviewed the CT studies and medical records for nine patients in whom CT had shown clinically unsuspected pulmonary thromboembolism. The study group consisted of seven men and two women ranging in age from 51 to 75 years, who were referred for CT over a 5-year period for a variety of indications. The location of the emboli and the presence and location of parenchymal and pleural abnormalities were determined. Subsequent changes in patient care were analysed. RESULTS: The locations of the thromboemboli were described according to pulmonary zone. One case involved zone 1 (main pulmonary artery to a lung), all involved zone 2 (first-order branches), and four involved extension into zone 3 (second-order branches). No emboli were distinguished in zone 4 (beyond the segmental arteries). Four patients had pleural-based opacities characteristic of infarcts, and three had pleural effusions. Eight patients underwent confirmatory testing. A vena cava filter was placed in three patients, one of whom also received anticoagulation therapy. The other six patients were treated by anticoagulation alone. All of the patients survived and were discharged. CONCLUSION: Radiologists should watch carefully for occult pulmonary thromboembolism when interpreting CT studies of the thorax. Establishing this diagnosis can result in immediate changes to treatment and possibly a reduction in the substantial morbidity and mortality associated with untreated pulmonary emboli.

Amino acid concentrations in hypothalamic and caudate nuclei during microwave-induced thermal stress: analysis by microdialysis.

Exposure to radiofrequency radiation (RFR) may produce thermal responses. Extracellular amino acid concentrations in the hypothalamus (Hyp) and caudate nucleus (CN) were measured by using in vivo microdialysis before and during exposure to RFR. Under urethane anesthetic, each rat was implanted stereotaxically with a nonmetallic microdialysis probe and temperature probe guides and then placed in the exposure chamber. The rat laid on its right side with its head and neck placed directly under the wave guide. Temperature probes were placed in the left brain, right brain, face (subcutaneously), left tympanum, and rectum. Each microdialysis sample was collected over a 20 min period. The microdialysis probe was perfused for 2 h before the rat was exposed to 5.02 GHz radiation (10 microseconds pulse width, 1000 pulses/s). The right and left sides of the brain were maintained at approximately 41.2 and 41.7 degrees C, respectively, throughout a 40 min exposure period. Initially when the brain was being heated to these temperatures, the time-averaged specific absorption rates (SARs) for the right and left sides of the brain were 29 and 40 W/kg, respectively. Concentrations of aspartic acid, glutamic acid, serine, glutamine, and glycine in dialysate were determined by using high-pressure liquid chromatography with electrochemical detection. In the Hyp and CN, the concentrations of aspartic acid, serine, and glycine increased significantly during RFR exposure (P < .05). These results indicate that RFR-induced thermal stress produces a general change in the amino acid concentrations that is not restricted to thermoregulatory centers. Changes in the concentrations of glutamic acid (Hyp, P = .16; CN, P = .34) and glutamine (Hyp, P = .13; CN, P = .10) were not statistically significant. Altered amino acid concentrations may reveal which brain regions are susceptible to damage in response to RFR-induced thermal stress.

Translabial ultrasonography and placenta previa: does measurement of the os-placenta distance predict outcome?

The aim of this study was to assess the value of the measurement of os-placenta distance by translabial ultrasonography in the evaluation of placenta previa. This method was used in 40 women with suspected placenta previa to measure the distance between the placenta and internal cervical os. Sonographic diagnoses were compared to placental location determined at delivery. Translabial ultrasonography proved superior to the transabdominal route in both diagnosis and exclusion of placenta previa. Measurement of the os-placenta distance can be used as an adjunct to clinical assessment to predict the likelihood of safe vaginal delivery in cases of suspected placenta previa.

Human orthotopic small intestine transplantation: radiologic assessment.

The authors describe the postoperative anatomy and review the radiologic examinations of five patients who underwent orthotopic small intestine or combined orthotopic liver and small intestine transplantation. Mucosal thickening of the transplanted intestine was demonstrated on the first postoperative contrast material-enhanced images and was due to submucosal edema. This resolved within 2 weeks in the long-term survivors. Bowel peristalsis appeared normal as early as 31 days after transplantation. Contrast-enhanced examinations of the intestine were useful to exclude surgical complications such as anastomotic leaks or strictures, but were insensitive for biopsy-proved cytomegalovirus enteritis or rejection.