The paediatric thymus: recognising normal and ectopic thymic tissue.

The appearance of the paediatric thymus changes as the normal process of thymic involution occurs. Thymic tissue may be orthotopic within the anterior mediastinum or ectopically located along the course of its embryological development. The variable appearance of orthotopic and ectopic thymic tissue in children on imaging studies may lead to misinterpretation of the normal thymus as pathology. Recognition of normal thymic tissue can mitigate unnecessary further diagnostic testing and patient anxiety. In this review, we discuss the embryological development and anatomical variants of normal thymus, and demonstrate the multimodality imaging features of the normal thymus in children, including positron-emission tomography, and diffusion-weighted imaging and in- and opposed-phase imaging on magnetic resonance imaging. We demonstrate the normal thymus mimicking pathological processes and discuss features that distinguish normal thymus, including thymic rebound hyperplasia, from pathology.

Rapid Development and Implementation of an ECMO Program.

Extracorporeal membrane oxygenation (ECMO) is an established therapy in the management of patients with refractory cardiogenic shock or acute respiratory failure. In this report, we describe the rapid development and implementation of an organized ECMO program at a facility that previously provided ad hoc support. The program provides care for patients within the Emory Healthcare system and throughout the Southeastern United States. From September 2014 to February 2015, 16 patients were treated with either venovenous or venoarterial ECMO with a survival to decannulation of 53.3% and survival to intensive care unit discharge of 40%. Of the 16 patients, 10 were transfers from outside facilities of which 2 were remotely cannulated and initiated on ECMO support by our ECMO transport team. Complications included intracerebral hemorrhage, bleeding from other sites, and limb ischemia. The results suggest that a rapidly developed ECMO program can provide safe transport services and provide outcomes similar to those in the existing literature. Key components appear to be an institutional commitment, a physician champion, multidisciplinary leadership, and organized training. Further study is required to determine whether outcomes will continue to improve.

Disrupted working body schema of the trunk in people with back pain.

BACKGROUND: To test whether working body schema of the trunk is disrupted in people with back pain using a motor imagery task in which one decides whether a pictured model has their trunk rotated to the left or to the right. The authors hypothesised that chronic back pain is associated with reduced accuracy of left/right trunk rotation judgements. METHODS: 21 Patients with back pain and 14 controls completed two tasks, each involving two trials of 40 images: a left/right hand judgement task, which was used as a control task, and the left/right trunk rotation judgement task. Two (task) × three (group: bilateral back pain, unilateral back pain and control) analyses of variance were undertaken on mean response time and accuracy. RESULTS: Response time was similar across participants and tasks (NS). Accuracy was not. The patients with bilateral back pain made more mistakes on the left/right trunk rotation task than patients with unilateral back pain, who in turn made more mistakes on that task than the controls (body part × group interaction; p<0.001). The mean (95% CI) accuracy for left/right trunk rotation judgements was 53.4% (44.5% to 62.3%) for the patients with bilateral back pain, 67.2% (60.2% to 74.1%) for the patients with unilateral back pain and 87% (75% to 98%) for the control participants. This pattern was not observed on the left/right-hand judgement task, on which all three groups made correct judgements about 83% of the time (NS). DISCUSSION: Chronic back pain is associated with disruption of the working body schema of the trunk. This might be an important contributor to motor control abnormalities seen in this population.

Local staging of Wilms' tumor--computerized tomography correlation with histological findings.

PURPOSE: The aim of this study was to assess the accuracy of computed tomography (CT) in the local staging of Wilms' tumor. METHODS: Twenty-six patients with unilateral, nonmetastatic Wilms' tumors were accrued over the period of 1990 through 1997. Preoperative CT staging was performed before surgical biopsy or excision. The abdominal CT images were reviewed and staged for local disease according to National Wilms' Tumour Study (NWTS) Group Staging V as either intrarenal disease (Stage I), local extrarenal extension amenable to complete local excision (Stage II), or advanced local disease (Stage III). Patients with metastatic (Stage IV) and bilateral disease (Stage V) were excluded from our study. Results were compared to histological findings. RESULTS: CT scan correctly staged 10 of 26 cases (38%) of Wilms' tumor. CT scan overstaged 12 of 16 (75%) localized renal disease (Stage I) and local extension (Stage II) tumors, and understaged 4 of 10 (40%) localized spread (Stage III) tumors. CONCLUSIONS: CT scan appears to have poor correlation to histological staging. Therefore, basing therapy solely on radiological imaging may lead to some patients receiving more intense therapy than necessary, whereas others do not receive sufficient therapeutic regimens. Histological assessment of the excised mass should remain the standard for staging Wilms' tumors.

Knee magnetic resonance imaging in childhood chronic monarthritis.

OBJECTIVE: To describe the usefulness of magnetic resonance imaging (MRI) of the knee in the evaluation of chronic monarthritis of uncertain cause in childhood. METHODS: We retrospectively reviewed 21 children referred to our clinic with a putative diagnosis of chronic inflammatory monarthritis of the knee who had MRI performed between May 1993 and June 1997. The median age was 13 years (range 2-17) and 11 were girls. RESULTS: The clinical diagnosis prior to MRI assessment was inflammatory arthritis in 16 patients, and a primary noninflammatory cause in 5. MRI was done in the patients with presumptive inflammatory arthritis when there were atypical symptoms, signs, or radiographs (n = 14), or when they failed to respond to therapy (n = 2). In the patients with a presumptive noninflammatory diagnosis, MRI was performed to clarify the diagnosis. Twelve children (57%) had MRI evidence of a noninflammatory diagnosis. In 4 children (19%) the MRI study indicated the presence of arthritis, and in 5 children (24%) the MRI studies were normal. The noninflammatory diagnoses included: lipoma arborescens (n = 1), vascular malformation [intraarticular (n = 1), extraarticular (n = 1)], synovial chondromatosis (n = 2), partial anterior cruciate ligament tear (n = 2), traumatic bone contusion (n = 2), possible meniscal tear (n = 1), osteochondritis dissecans (n = 1), and a soft tissue mass of uncertain significance in the suprapatellar pouch (n = 1). CONCLUSION: Inflammatory arthritis is usually diagnosed by clinical assessment alone. Uncommonly, when a single joint is involved, and atypical features are identified by a pediatric rheumatologist, other causes of chronic pain and swelling need to be excluded. In this selected patient population, MRI is a useful tool either to confirm the presence of inflammatory arthritis or to investigate a wide range of pathology that can mimic knee joint arthritis.

Wavelet variations on the Shannon sampling theorem.

The Shannon sampling theorem asserts that a continuous square-integrable function on the real line which has a compactly supported Fourier transform is uniquely determined by its restriction to a uniform lattice of points whose density is determined by the support of the Fourier transform. This result can be extended to the wavelet representation of functions in two ways. First, under the same type of conditions as for the Shannon theorem, the scaling coefficients of a wavelet expansion will determine uniquely the given square-integrable function. Secondly, for a more general function, there is a unique extension from a given set of scaling coefficients to a full wavelet expansion which minimizes the local obstructions to translation invariance in a variational sense.

Comparison of stimulable phosphor technology and conventional screen-film technology in pediatric scoliosis.

One hundred consecutive patients being investigated for scoliosis were studied using a double cassette containing a conventional film screen and a stimulable phosphor plate. The images were separated, randomised and scored thrice by three radiologists for anatomic structure visualisation. The exposure to the plate and film and repeat rate were measured. Scoliosis angles were comparable on both sets of images, however, visualisation of vertebrae, vertebral end plates, pedicles, spinous processes and other structures were significantly improved (p < 0.0001). Intra- and inter-observer reliability was high with good intraclass correlation. There was a 40% potential exposure reduction, and retakes were decreased from 3 to 0%. We conclude that stimulable phosphor images give better anatomic structure visualisation with potential radiation exposure reduction and lower repeat rate.

Quality of mucosal coating in double-contrast barium enema studies: comparison of two barium preparations.

To determine which of two types of barium preparation, a dry powder (AC-14, E-Z-EM, Montreal) or a premixed suspension (Liquid Polibar Plus, E-Z-EM), gives better mucosal coating for double-contrast enema studies, the authors compared the results of two series of 80 examinations each, one for each of the preparations. The films were retrospectively reviewed by two independent observers, who did not know which preparation had been used for a given examination. Mucosal coating was graded on a five-point scale and the amount of barium on a three-point scale. Each area of the colon--the cecum, the ascending, the transverse and the descending colon and the rectosigmoid--was rated separately. The premixed barium suspension yielded significantly better mucosal coating than the dry powder in all areas of the colon (p < 0.01). There was no significant difference between the two preparations in the amount of barium deposited in any region of the colon (p > 0.05) or in the proportion of unsatisfactory examinations (p > 0.05). The authors conclude that the premixed suspension yielded better-quality mucosal coating than a suspension made from the dry powder and resulted in a similar high proportion of technically satisfactory studies.

Maple tree knee: a unique foreign body--value of ultrasound and CT examination.

This report describes an intraosseous maple branch fragment which presented on initial radiographs as a benign appearing lytic bone lesion. Sonography and CT confirmed the presence of intraosseous and intra-articular foreign body and chronic foreign body reaction.

Nitrous oxide and cerebrospinal fluid markers of ischaemia following cardiopulmonary bypass.

Twenty patients with good ventricular function undergoing coronary artery bypass surgery were studied to determine whether the pre-bypass use of nitrous oxide resulted in any differences in cerebrospinal fluid markers indicative of cerebral ischaemia. All patients were anaesthetised with diazepam, fentanyl and pancuronium, after which ten patients received 50-60% nitrous oxide in oxygen until commencement of bypass, and the remaining patients 100% oxygen. Because of the known effect of nitrous oxide in expanding gaseous bubbles, any neurological dysfunction of gaseous microembolic origin may be worsened in the presence of nitrous oxide. Patients were lumbar punctured 24 hours after cardiopulmonary bypass and cerebrospinal fluid analysed for the following markers of central nervous system ischaemia: creatine kinase, lactate, total protein, noradrenaline, adrenaline and adenylate kinase. There was a statistically significant difference in cerebrospinal fluid lactate between the two groups. There were no statistically significant differences in the other cerebrospinal fluid markers of ischaemia.

Comprehensive behavioral management of complex tinnitus: a case illustration.

This paper describes a comprehensive program for behavioral management of complex tinnitus. The clinical characteristics and typical treatment of tinnitus are reviewed. Psychosocial sequelae are discussed in terms of their exacerbation of the symptom and their potential as foci of treatment. The management problems of tinnitus are considered analogous to those of chronic pain. A case illustration is provided with a description of the treatment process. The comprehensive behavioral program discussed in the present paper included biofeedback therapy, pain management training, social skills training, assertion training, in vivo exposure to being alone, cognitive treatment of depression, and marital therapy. Outcomes were monitored multidimensionally. Self-report of tinnitus severity decreased after the 6th treatment day and stabilized at a "mild" rating after the 9th day. Skin temperature readings at baseline increased and stabilized after the 8th day, and the patient was able to reliably increase skin temperature on request. Scores on the Beck Depression Inventory and the Willoughby Personality Schedule, and a self-rating of Fear of Being Alone dropped markedly by the end of treatment. Follow-up data at 3 months indicated maintenance of gains.

Calcivirus (SMSV-5) infection in experimentally inoculated Opaleye fish (Girella nigricans).

At 15 degrees C, San Miguel sea lion virus infected fish (Girella nigricans), producing 10(7).6 TCID50 per gram of spleen, replicated in Vero cells (10(8) TCID50/gm) and retained viability after 14 days exposure to salt water (10(5) TCID50/ml dropped to 10(2).

A new calicivirus isolated from a marine mammal.

A new serotype of calicivirus, designated as San Miguel sea lion virus type 6 (SMSV-6), was isolated from vesicular lesions on the flipper of a California sea lion pup. Serologic studies show that SMSV-6 neutralizing antibodies (SN) occur frequently among California sea lions and occasionally among northern fur seals. Feral swine, 1- to 6-week elephant seal pups and grey whales tested negative for SMSV-6 antibody.

Mercapturic acid formation in the developing rat.

1. Young female rats dosed with 1-bromo[1-14C]propane excrete the same metabolites as adult females but in different relative proportions. Propylcysteine was detected as one of the metabolites in rats of all ages studied but represented a higher proportion of the total metabolites excreted in rats aged 5 and 11 days. 2. Hepatic GSH-S-alkytransferase activity was low in females at birth increasing up to the age of about thirty days. No activity was detected in the livers of the males at birth and up to 6 days of age; thereafter the level of activity increased up to 35-40 days. 3. Propylcysteine was excreted as prophylmercapturic acid and propylmercapturic acid sulphoxide by female rats of all ages. The amount of sulphoxide excreted relative to mercapturic acid excreted was higher in rats up to the age of 16 days than in older animals.