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Background: Persisting post-concussion symptoms (PPCS) is a complex, multifaceted condition in which individuals continue to experience the symptoms of mild traumatic brain injury (mTBI, concussion) beyond the timeframe that it typically takes to recover. Currently, there is no way of knowing which individuals may develop this condition. Method: Patients presenting to a hospital emergency department (ED) within 48 h of sustaining a mTBI underwent neuropsychological assessment and demographic, injury-related information and blood samples were collected. Concentrations of blood-based biomarkers neuron specific enolase, neurofilament protein-light, and glial fibrillary acidic protein were assessed, and a subset of patients also underwent diffusion tensor&ndash, magnetic resonance imaging, both relative to healthy controls. Individuals were classified as having PPCS if they reported a score of 25 or higher on the Rivermead Postconcussion Symptoms Questionnaire at ~28 days post-injury. Univariate exact logistic regression was performed to identify measures that may be predictive of PPCS. Neuroimaging data were examined for differences in fractional anisotropy (FA) and mean diffusivity in regions of interest. Results: Of n = 36 individuals, three (8.33%) were classified as having PPCS. Increased performance on the Repeatable Battery for the Assessment of Neuropsychological Status Update Total Score (OR = 0.81, 95% CI: 0.61&ndash, 0.95, p = 0.004), Immediate Memory (OR = 0.79, 95% CI: 0.56&ndash, 0.94, p = 0.001), and Attention (OR = 0.86, 95% CI: 0.71&ndash, 0.97, p = 0.007) indices, as well as faster completion of the Trails Making Test B (OR = 1.06, 95% CI: 1.00&ndash, 1.12, p = 0.032) at ED presentation were associated with a statistically significant decreased odds of an individual being classified as having PPCS. There was no significant association between blood-based biomarkers and PPCS in this small sample, although glial fibrillary acidic protein (GFAP) was significantly increased in individuals with mTBI relative to healthy controls. Furthermore, relative to healthy age and sex-matched controls (n = 8), individuals with mTBI (n = 14) had higher levels of FA within the left inferior frontal occipital fasciculus (t (18.06) = &minus, 3.01, p = 0.008). Conclusion: Performance on neuropsychological measures may be useful for predicting PPCS, but further investigation is required to elucidate the utility of this and other potential predictors.

Background Anterior hip pain after total hip replacement (THR) can be caused by iliopsoas impingement (IPI). Validation of CT measured cup version is well published; however quantification of the anterior cup prominence has not been validated. Therefore, we did an in vitro study aiming to: 1) assess the accuracy of the current method of measuring the prominence of the acetabular component using a dry bone model, 2) develop a CT protocol based on bony anatomical landmarks that improves the accuracy of these measurements. Hypothesis We hypothesise that utilising reproducible anatomical landmarks on the acetabulum will improve the accuracy of measurement of anterior prominence at the psoas valley. Methods A dry bone pelvic model was implanted with bilateral acetabular cups. The cup was manipulated into ten different combinations of inclination and version, and anterior prominence directly measured in relation to the acetabular rim. A CT scan was performed for each position. Anterior prominence was then measured by two radiologists, first using standard methods (axial slice at level of center of femoral head) and then again using a novel protocol (based on the position of the psoas valley in relation to the inferior medial acetabular notch). Results Mean errors between direct measurement of anterior prominence and radiologist reported measurements using standard protocol were 6.94 mm ± 5.24 (SD) (95%Confidence Interval: 3.25–4.27) and 5.14 mm ± 3.07 (95%CI: 1.9-2.5) with a tendency towards overestimation of prominence. Using an anatomical landmark based protocol, mean error was reduced to 3.0 mm ± 1.9 (95%CI: 1.16–1.53) and 4.3 mm ± 4.3 (95%CI: 2.67–351) on the first attempt, and to 1.7 mm ± 1.9 (95%CI: 1.15–1.52) and 2.1 mm ± 1.4 (95%CI: 0.87–1.15) on the second attempt. Concordance correlation improved from 0.43 (95% CI: 0.19–0.68) and 0.59 (95% CI: 0.44–0.79) using the standard protocol, to 0.88 (95%CI: 0.61–0.91) and 0.9 (95%CI: 0.56 - 0.92) using the novel protocol. Conclusions There is a difference in mean error and reliability between radiologically measured values for anterior prominence and values measured directly with present methods. The use of our novel protocol based on bony acetabular landmarks, significantly improves the accuracy of measurement. This protocol may improve reproducibility and the accuracy of this measurement and aid in the decision between tenotomy or revision of the acetabular component. Level of evidence III, in vitro study comparing diagnostic tools.

Background Anterior hip pain after total hip replacement (THR) can be caused by iliopsoas impingement (IPI). Validation of CT measured cup version is well published; however quantification of the anterior cup prominence has not been validated. Therefore, we did an in vitro study aiming to: (1) assess the accuracy of the current method of measuring the prominence of the acetabular component using a dry bone model; (2) develop a CT protocol based on bony anatomical landmarks that improves the accuracy of these measurements. Hypothesis We hypothesise that utilising reproducible anatomical landmarks on the acetabulum will improve the accuracy of measurement of anterior prominence at the psoas valley. Methods A dry bone pelvic model was implanted with bilateral acetabular cups. The cup was manipulated into ten different combinations of inclination and version, and anterior prominence directly measured in relation to the acetabular rim. A CT scan was performed for each position. Anterior prominence was then measured by two radiologists, first using standard methods (axial slice at level of centre of femoral head) and then again using a novel protocol (based on the position of the psoas valley in relation to the inferior medial acetabular notch). Results Mean errors between direct measurement of anterior prominence and radiologist reported measurements using standard protocol were 6.94 mm ± 5.24 (SD) (95%Confidence Interval: 3.25–4.27) and 5.14 mm ± 3.07 (95%CI: 1.9–2.5) with a tendency towards overestimation of prominence. Using an anatomical landmark based protocol; mean error was reduced to 3.0 mm ± 1.9 (95%CI: 1.16–1.53) and 4.3 mm ± 4.3 (95%CI: 2.67–351) on the first attempt, and to 1.7 mm ± 1.9 (95%CI: 1.15-1.52) and 2.1 mm ± 1.4 (95%CI: 0.87–1.15) on the second attempt. Concordance correlation improved from 0.43 (95% CI: 0.19–0.68) and 0.59 (95% CI: 0.44–0.79) using the standard protocol, to 0.88 (95%CI: 0.61–0.91) and 0.9 (95%CI: 0.56–0.92) using the novel protocol. Conclusions There is a difference in mean error and reliability between radiologically measured values for anterior prominence and values measured directly with present methods. The use of our novel protocol based on bony acetabular landmarks, significantly improves the accuracy of measurement. This protocol may improve reproducibility and the accuracy of this measurement and aid in the decision between tenotomy or revision of the acetabular component. Level of evidence III, in vitro study comparing diagnostic tools.

Descending necrotising mediastinitis (DNM) is an uncommon clinical entity which may arise secondary to primary odontogenic or neck infection in susceptible patients. Infection may spread contiguously via the alar or ’danger' space, a potential anatomical space posterior to the true retropharyngeal space.(1) Spread of infection to the mediastinum almost always necessitates urgent cardiothoracic surgical intervention.(2–4) This case report describes a male patient whose clinical deterioration following the diagnosis of submandibular abscess was investigated with CT imaging of the chest, where a diagnosis of DNM was made. Diagnosis was confirmed following surgical intervention and aspiration of pus from the mediastinum.

Context:Familial hypobetalipoproteinemia (FHBL) is a codominant disorder of lipoprotein metabolism characterized by decreased plasma concentrations of low-density lipoprotein (LDL)-cholesterol and apolipoprotein B (apoB).Objective:The objective was to examine the effect of heterozygous APOB L343V FHBL on postprandial triglyceride-rich lipoprotein (TRL) and fasting lipoprotein metabolism.Methods:Plasma incremental area under the curve apoB-48 and apoB-48 kinetics were determined after ingestion of a standardized oral fat load using compartmental modeling. Very low-density lipoprotein (VLDL)-, intermediate-density lipoprotein (IDL)-, and LDL-apoB kinetics were determined in the fasting state using stable isotope methods and compartmental modeling.Results:The postprandial incremental area under the curve (0–10 h) in FHBL subjects (n = 3) was lower for large TRL-triglyceride (−77%; P < .0001), small TRL-cholesterol (−83%; P < .001), small TRL-triglyceride (−88%; P < .001), and for plasma triglyceride (−70%; P < .01) and apoB (−63%; P < .0001) compared with controls. Compartmental analysis showed that apoB-48 production was lower (−91%; P < .05) compared with controls. VLDL-apoB concentrations in FHBL subjects (n = 2) were lower by more than 75% compared with healthy, normolipidemic control subjects (P < .01). The VLDL-apoB fractional catabolic rate (FCR) was more than 5-fold higher in the FHBL subjects (P = .07). ApoB production rates and IDL- and LDL-apoB FCRs were not different between FHBL subjects and controls.Conclusions:We conclude that when compared to controls, APOB L343V FHBL heterozygotes show lower TRL production with normal postprandial TRL particle clearance. In contrast, VLDL-apoB production was normal, whereas the FCR was higher in heterozygotes compared with lean control subjects. These mechanisms account for the marked hypolipidemic state observed in these FHBL subjects.

Objective: Familial hypobetalipoproteinemia (FHBL) is characterized by mutations in APOB, the majority of these causing protein truncations, and low plasma levels of apolipoprotein (apo) B. The hypobetalipoproteinemia may be due to enhanced clearance and possibly reduced production of apoB-containing lipoproteins;the mechanism may depend on the length of the apoB truncation. We studied fasting lipoprotein metabolism in an FHBL subject heterozygous for a mutation causing a truncated apoB, apoB-80. Design and Methods: Very low density lipoprotein (VLDL)-, intermediate density lipoprotein (IDL)-, and low density lipoprotein (LDL)-apoB kinetics were determined in the fasting state using stable isotope methods and compartmental modeling. Results: Compared with lean normolipidemic controls the apoB-80 FHBL subject had an elevated VLDL-apoB fractional catabolic rate and lower LDL production. ApoB production rates and IDL- and LDL-apoB fractional catabolic rates were not different. Conclusion: FHBL subjects heterozygous for a mutation truncating apoB to 80% of full-length are able to produce VLDL-apoB normally, but have rapid clearance of these particles, resulting in low levels of circulating apoB. (C) 2016 The Canadian Society of Clinical Chemists. Published by ELSEVIER. All rights reserved.

Background and Purpose— Elevated concentrations of homocysteine are associated with cerebral small vessel disease (CSVD). b-vitamin supplementation with folate and vitamins b 12 and b 6 reduces homocysteine concentrations. In a substudy of the VITAmins TO Prevent Stroke (VITATOPS) trial, we assessed the hypothesis that the addition of once-daily supplements of b vitamins would reduce the progression of CSVD-related brain lesions. Methods— A total of 359 patients with recent stroke or transient ischemic attack, who were randomly allocated to double-blind treatment with placebo or b vitamins, underwent brain MRI at randomization and after 2 years of b-vitamin supplementation. MR images were analyzed blinded to treatment allocation. Outcomes related to the prespecified hypothesis were progression of white matter hyperintensities and incident lacunes. We also explored the effect of b-vitamin supplementation on the incidence of other ischemic abnormalities. Results— After 2 years of treatment with b vitamins or placebo, there was no significant difference in white matter hyperintensities volume change (0.08 vs 0.13cm 3 ; P =0.419) and incidence of lacunes (8.0% vs 5.9%, P =0.434; odds ratio=1.38). In a subanalysis of patients with MRI evidence of severe CSVD at baseline, b-vitamin supplementation was associated with a significant reduction in white matter hyperintensities volume change (0.3 vs 1.7cm 3 ; P =0.039). Conclusions— Daily b-vitamin supplementation for 2 years did not significantly reduce the progression of brain lesions resulting from presumed CSVD in all patients with recent stroke or transient ischemic attack but may do so in the subgroup of patients with recent stroke or transient ischemic attack and severe CSVD. Clinical Trial Registration— http://vitatops.highway1.com.au/ . Unique identifier: NCT00097669 and ISRCTN74743444.

We examined the association between cauda equina nerve root volume and sensory block height in 15 patients undergoing spinal anaesthesia with 0.5% glucose-free bupivacaine. Magnetic resonance imaging and a separate image segmentation program were used to calculate the volume of the nerve roots. Nerve root volume was also correlated with lumbosacral cerebrospinal fluid volume and with patients' physical characteristics. Nerve root volume correlated negatively with sensory block height (Spearman rho -0.61 (95% CI -0.85 to -0.14)) and body mass index (Spearman rho -0.66 (95% CI -0.87 to -0.24)) but positively with cerebrospinal fluid volume (Spearman rho 0.76 (95% CI 0.43-0.91)). Factors that are thought to influence cerebrospinal fluid volume, such as body mass index, might similarly affect the volume of the nerve roots. The size of the nerve roots may influence the spread of spinal anaesthesia.

Objectives This randomised controlled crossover trial examined the efficacy of botulinum toxin type A (BoNT-A) injection, plus an exercise programme, to remediate chronic anterior knee pain (AKP) associated with quadriceps muscle imbalance. Methods 24 individuals with refractory AKP received either BoNT-A (500 U Dysport) or the same volume saline injection to the vastus lateralis (VL) muscle and performed home exercises focusing on re-training the vastus medialis (VM) muscle. All subjects were offered open-label injection at 12 weeks. Knee-related disability (anterior knee pain scale; AKPS) and activity-induced pain (10 cm visual analogue scale) at 12 weeks were the primary outcomes. Peak isometric extensor force was recorded and normalised VL:VM ratios were derived from simultaneous surface electromyography. Selfreported pain and disability measures were collected at six time points to a mean of 20±8 months. Results 14 subjects received BoNT-A and 10 placebo injection. Improvement at 12 weeks was significantly greater for BoNT-A compared with placebo-injected subjects for the AKPS (p

Background: Scientific evidence is mounting for an association between traumatic brain injury and enhanced osteogenesis. The aim of this study was to correlate the in vitro osteoinductive potential of serum with the features of fracture-healing and the extent of brain damage in patients with severe traumatic brain injury and bone fracture. Methods: Patients with a long-bone fracture and a traumatic brain injury (seventeen patients) or without a brain injury (twenty-four patients) were recruited. The Glasgow Coma Scale score was determined on admission. Radiographs of the fracture were made before surgery, at six weeks, and at three, six, and twelve months after surgery. The time to union was estimated clinically and radiographically, and the callus ratio to shaft diameter was calculated. Serum samples were collected at six, twenty-four, seventy-two, and 168 hours after injury, and their osteogenic potential was determined by measurement of the in vitro proliferation rate of the human fetal osteoblastic cell line hFOB1.19. Results: Patients with a traumatic brain injury had a twofold shorter time to union (p = 0.01), a 37% to 50% increased callus ratio (p < 0.01), and their sera induced a higher proliferation rate in hFOB cells (p < 0.05). A linear relationship was revealed between hFOB cell proliferation rates and the amount of callus formed (p < 0.05). The Glasgow Coma Scale score was correlated with the callus ratio on both radiographic projections (p < 0.05), time to union (p = 0.04), and the proliferation rate of hFOB cells at six hours after injury (p = 0.03). Conclusions: Patients with a severe brain injury release unknown humoral factors into the blood circulation that enhance and accelerate fracture-healing.

To examine the effect of intramuscular injection of botulinum toxin type A [Dysport] to reduce relative overactivity of the vastus lateralis [VL] muscle, in conjunction with re-training of vastus medialis [VM] muscle as an adjunct to rehabilitation for chronic anterior knee pain.Eight females with chronic (6 months) history of anterior knee pain, who had failed conservative management, were studied in this open label pilot study. Intramuscular Dysport injection [300 - 500 units] to the distal third of VL muscle was followed by a 12-week customized home exercise programme to improve recruitment of VM muscle and functional knee control. VL and VM muscle cross sectional area from a standardized spiral CT sequence, isometric quadriceps strength (dynamometry), timed stair task, self-reported pain and disability were assessed.Subjects reported reduced knee pain and brace dependency and increased participation in sporting and daily living activities. Isometric quadriceps muscle strength was maintained or improved despite significant atrophy, evident on CT, of the distal component of VL in the treated limb. Time taken to ascend and descend a flight of stairs improved in all subjects. Subjective and objective improvements were maintained at 24-week follow-up.These pilot data provide preliminary support for the role of Dysport as an adjunct to non-surgical management of individuals with chronic anterior knee pain. Larger double blind, randomized, placebo-injection controlled studies of this novel approach to improving patellofemoral mechanics are needed to establish the efficacy of this intervention.

Objective: To examine the association between the kinetics of very-low-density-lipoprotein (VLDL)-apolipoprotein B-100 (apoB) and intraperitoneal, retroperitoneal, subcutaneous abdominal, and total adipose tissue masses (IPATM, RPATM, SAATM, and TATM, respectively) in overweight/obese men. Research Methods and Procedures: Hepatic secretion of VLDL was measured using an intravenous infusion of 1-[13C]-leucine in 51 men with a wide range of body mass index (25.1 to 42.2 kg/m2). Isotopic enrichment of VLDL-apoB was measured using gas chromatography-mass spectrometry and a multicompartmental model used to estimate VLDL-apoB metabolic parameters. IPATM, RPATM, and SAATM (kilograms) were quantified between T11 and S1 using magnetic resonance imaging; TATM (kilograms) was determined using bioelectrical impedance. Insulin resistance was estimated by homeostasis model assessment (HOMA) score. Results: In stepwise regression, IPATM was the best predictor of hepatic secretion of VLDL-apoB (r = 0.390, p < 0.005) and TATM was the best predictor of VLDL-apoB fractional catabolic rate (r = 0.282, p < 0.05). IPATM remained significantly associated with VLDL-apoB secretion after adjusting for TATM or HOMA score (r = 0.360, p < 0.01 and r = 0.310, p < 0.05, respectively). This association was also independent of age, dietary intake, and body mass index. None of the fat compartments were significantly associated with the fractional catabolic rate of VLDL-apoB after adjusting for HOMA score. Discussion: In overweight/obese men, the quantity of both IPATM and TATM determine the kinetics of VLDL-apoB. The effect of IPATM on VLDL-apoB secretion is independent of both total fat mass and the degree of insulin resistance.

Some previously immunodeficient HIV patients responding to antiretroviral therapy display poor recovery of CD4+ T cells. Evaluation of the contribution of thymic function requires sensitive detection and quantitation of metabolically active thymic tissue. We describe patients with low but detectable

The present retrospective study reviewed and examined the prevalence of thoracic disc degeneration, end-plate lesions and osteophytes in the thoracic spine using T2-weighted sagittal magnetic resonance images (MRI). The sample comprised 216 thoracic spine cases (101 males and 115 females), aged from 1 to 85 years (mean age = 42±19.7 years). Nuclear and anular degeneration, end-plate lesions and osteophytes were graded using a 3-point scale. The prevalence of degeneration was highest in the nucleus (86%) and lowest in the end-plates (63%). Males had a higher prevalence of degeneration in the nucleus, anulus and end-plates, and a lower prevalence of osteophytes compared to females. Increasing cranio-caudal trends in the prevalence of degeneration in the nucleus, anulus and end-plates were observed, and these trends were statistically significant (p

There are limited data detailing the pattern of age and gender-related changes to the thoracic vertebral bodies and intervertebral discs. A retrospective MR investigation, involving T1-weighted midsagittal images from 169 cases, was undertaken to examine age influences on the anterior wedge (anteroposterior height ratio or Ha/Hp), biconcavity (midposterior height ratio or Hm/Hp), and compression indices (posterior height/anteroposterior diameter or Hp/D) of the thoracic vertebral bodies. Disc degenerative changes in the annulus, nucleus, end-plate and disc margin were noted on T2-weighted sagittal images for the 169 cases, based on a 3-level grading system. A linear age-related decline in the Ha/Hp and Hm/Hp indices was noted. The Hp/D index increased during the first few decades of life, then decreased gradually thereafter. The prevalence of abnormal findings in the annuli, nuclei and disc margins increased with increasing age, particularly in the mid and lower thoracic discs. Greater disc degenerative changes were observed in males. These findings provide further insight into the nature of thoracic vertebral shape changes across the lifespan, and the typical patterns of degeneration of the thoracic intervertebral discs.

The study aimed to investigate the variability in interpreting magnetic resonance imaging (MRI) films for thoracic disc degeneration, using a 5-point MRI disc grading scale and a modified 3-point scale. Forty-six T2-weighted sagittal thoracic MRI films, comprising 18 males and 28 females, aged 7 to 73 years, (mean age =41±16.3 years), were randomly selected from 318 archived cases. Nuclear and anular degeneration, end-plate lesions and osteophytes were graded on the first 30 cases using a modified 3-point grading scale. The next 30 cases were evaluated using the 5-point grading scale. Repeat evaluations for both scales were conducted after a three- to six-month interval. The intra-rater kappa coefficient was higher using the 3-point scale (0.71 to 0.87, p < 0.001) compared to the 5-point scale (0.57 to 0.78, p < 0.001) for the end-plate–disc–end-plate components. The lowest intra-rater reliability was for osteophytes and the highest was for the nucleus. The intra-rater reliability was generally higher in the upper thoracic region compared to the mid and lower thoracic regions.

Objective. The aim of this study was to examine age, gender, and segmental trends in thoracic vertebral body shape, utilising thoracic spine magnetic resonance images involving an age range spanning the life span. Design. A quantitative, cross-sectional, retrospective study design involving a sample of convenience. Background. Thoracic vertebral shape data are commonly derived from radiographic resources. The non-ionising properties of magnetic resonance imaging and availability of digital data for image analysis suggest potential for MR-based morphometric studies. For the thoracic spine, there is limited vertebral shape data on males, while few studies have examined the pattern of age-related changes across the life span. Methods. Morphometry was performed on 220 mid sagittal T1-weighted MR images using image analysis software. Three indices of vertebral shape were utilised: the antero-posterior height ratio or anterior wedge index, mid-posterior height ratio or biconcavity index, and ratio of posterior vertebral height to mid antero-posterior diameter or compression index. Results. Different segmental patterns were noted for the vertebral shape indices. Significantly lower mean values were noted in males for the compression index. Age trends were significant, with a linear age-related decline demonstrated for the anterior wedge and biconcavity indices, and a quadratic trend noted for the compression index. Conclusions. Thoracic vertebral body shape may be uniquely described using specific shape indices, for examining various segmental, gender and age-associated changes. Relevance These results suggest the importance of defining specific reference criteria for thoracic vertebral body shape indices, particularly age-related data encompassing a wide age range. Magnetic resonance studies enable interpretation of vertebral shape data in relation to the wide spectrum of pathologies afflicting the thoracic spine, without the concerns of ionising radiation.

n Australia it is common for patients to move between public and private hospitals for their care. Patients are seen in the private practice environment for follow-up and ongoing treatment and management after discharge from public hospitals. The reverse is also true — patients who have diagnostic imaging studies in private clinics are referred to public hospitals for further management. The current system of transferring imaging studies from one location to another as hard copies or on compact disc leads to delays in management and occasionally adverse outcomes for the patient concerned. The need for a solution to this problem was precipitated by two cases. Patient A, who was taking warfarin therapy, presented with a large spontaneous subdural haemorrhage. The patient was referred to the neurosurgeons at a neurosurgical centre, but deteriorated while waiting for computed tomography (CT) images to accompany the transfer. Patient B presented with haematemesis. A contrast CT study revealed an aortoduodenal fistula. While waiting for CT images, the patient had another massive haematemesis and deteriorated and died while being transferred.

We aimed to examine the effect of genetic poly- morphisms of apolipoprotein B-100 (apoB) signal peptide and apolipoprotein E (apoE) on the hepatic secretion of very low density lipoprotein (VLDL) apoB in 29 men with visceral obesity. We studied apoB secretion using a primed (1 mg/kg), constant (1 mg/kg/h) intravenous infusion of (1- 13 C)leucine. The isotopic enrichment of VLDL apoB was determined using gas chromatography-mass spectrometry (GCMS). A multi-compartmental model was used to esti- mate the fractional turnover rate of VLDL apoB. Genotypes for the apoB signal peptide length polymorphism, 27 amino acid (SP27) and 24 amino acid (SP24), and apoE genotypes were determined using polymerase chain reaction. In sub- jects who were not apoE2 carriers and were homozygous for the SP27 of the apoB signal peptide, the hepatic secretion of VLDL apoB was significantly higher than in subjects who were not apoE2 carriers and were either heterozygous or homozygous for the SP24 allele (31.3 6 11.8 mg/kg fat-free mass/day, n 5 8 vs. 16.9 6 12.2 mg/kg fat-free mass/day, n 5 13, P 5 0.01). In subjects who were not apoE4 carriers and were either heterozygous or homozygous for the apoB SP24 allele, the hepatic secretion of VLDL apoB was significantly lower than in subjects who were not apoE4 carriers and were homozygous for the SP27 allele (15.8 6 12.9 mg/kg fat-free mass/day, n 5 13 vs. 27.4 6 11.5 mg/kg fat-free mass/day, n 5 7, P 5 0.03). The data suggest that in men with visceral obesity, the apoB signal peptide and apoE gen- otypes appear to be involved in the hepatic secretion of apoB.— Riches, F. M., G. F. Watts, F. M. van Bockxmeer, J. Hua, S. Song, S. E. Humphries, and P. J. Talmud. Apolipo- protein B signal peptide and apolipoprotein E genotypes as determinants of the hepatic secretion of VLDL apoB in obese men. J. Lipid Res. 1998. 39: 1752-1758.

Background Spinal rotation couples with lateral flexion as a composite movement. Few data report the in vivo mechanical deformation of the nucleus pulposus following sustained rotation. MRI provides a non-invasive method of examining nucleus pulposus deformation by mapping the hydration signal distribution within the intervertebral disc. Methods T1 weighted coronal and sagittal lumbar images and T2 weighted axial images at L1–2 and L4–5 were obtained from 10 asymptomatic subjects (mean age 29, range: 24–34 years) in sustained flexed and extended positions plus combined positions of left rotation with flexion and extension. Nucleus pulposus deformation was tracked by mapping the change in hydration profiles from coronal and sagittal pixel measurements. Findings An average sagittal change in position of 44° (SD 14.5°) from flexion to extension was recorded between L1 and S1 (range: 18°– 60°) resulting in a mean anterior nucleus pulposus deformation of 16% of disc hydration profile (range: 3.5%–19%) in 19/20 discs. When rotation was combined with either flexion or extension, mean coronal deformation was 4.8% (SD—5.1%; range: 0.4%–15%). Lateral nucleus pulposus deformation direction varied in rotation (44% deformed left and 56% deformed right). Intersegmental lateral flexion direction more strongly predicted nucleus pulposus deformation direction with 75% deforming contralaterally. Interpretation Nucleus pulposus deformation direction in young subjects was more predictable following sagittal position change than in rotation combined with flexion or extension. Deformation magnitude was reduced in rotated positions. Intersegmental lateral flexion was a stronger predictor of nucleus pulposus deformation direction.

Some previously immunodeficient HIV patients responding to antiretroviral therapy display poor recovery of CD4⁺ T cells. Evaluation of the contribution of thymic function requires sensitive detection and quantitation of metabolically active thymic tissue. We describe patients with low but detectable thymopoiesis assessed as circulating CD4⁺ naive T cells expressing CD31. High-resolution computed tomography and PET scans found no residual thymic tissue even though metabolic activity was demonstrable by PET in lymph nodes.

OBJECTIVES: To determine the prevalence of occult brain abnormalities in magnetic resonance imaging of active amphetamine users. DESIGN, SETTING AND PARTICIPANTS: Prospective convenience study in a tertiary hospital emergency department (ED). Patients presenting to the ED for an amphetamine-related reason were eligible for inclusion. We collected demographic data, drug use data, and performed a mini-mental state examination (MMSE). MAIN OUTCOME MEASURES: The proportion of patients with an abnormality on their MRI scan. RESULTS: Of 38 patients enrolled, 30 had MRI scans. Nineteen were male and their mean age was 26.7 +/- 5.4 years (range 19-41 years). The mean age of first amphetamine use was 18 years (range 13-26 years). Sixteen patients used crystal methamphetamine (mean amount 2.5 g/week), nine used amphetamine ("speed") (mean amount 2.9 g/week), and 23 used ecstasy (mean amount 2.3 tablets/week). Marijuana was smoked by 26 (mean amount 5.9 g/week), and 28 drank alcohol (mean amount 207 g/week). The median MMSE score was 27/30 (interquartile range, 26-29). Abnormalities on brain MRI scans were identified in six patients, most commonly an unidentified bright object (n = 4). CONCLUSION: In this pilot study of brain MRI of young people attending the ED with an amphetamine-related presentation, one in five had an occult brain lesion. While the significance of this is uncertain, it is congruent with evidence that amphetamines cause brain injury. Language: en

Background The nucleus pulposus deforms towards an area of least compression in response to offset loading, however, there is a lack of data reporting the deformation patterns of nuclear material in rotated positions of the lumbar spine. Our purpose was to assess a novel methodology using MRI to track nuclear deformation in response to flexion and extension positions, and the combined positions of flexion with left rotation and extension with left rotation, at L1–2 and L4–5. Methods Three asymptomatic female subjects, mean age 27 years, underwent T2 weighted MRI sequences in flexed, extended, and left rotated positions combined with flexion and extension. A pixel profile technique was employed to determine direction and magnitude of nuclear deformation. Results In 5 of 6 discs examined, deformation of the nucleus occurred anteriorly in extension and posteriorly in flexion. Left rotation resulted in migration of nuclear material to the right in 9 of 12 discs. Of the three discs that demonstrated a right nuclear migration, two occurred at L4–5 and one at L1–2. Interpretation This methodology demonstrated that nucleus pulposus deformation can be measured reliably in various positions achieved within the confines of the MRI. The consistent migration of nuclear material following sagittal plane movement and the less consistent response to rotation positions suggest other asymmetrical loading on the intervertebral disc may accompany rotation.

Summary In the lumbosacral spine, unilateral facet joint dislocation is an infrequent injury, which is often associated with fractures at the involved or other lumbar levels. The rare occurrence of unilateral lumbosacral facet joint dislocation without any associated fractures is presented with CT and MRI, and surgical correlation. To our knowledge, cross-sectional imaging of this injury has not previously been described in the published literature.

Summary Pancreatic malignancy can be staged by a number of different investigations, either alone or in combination. The purpose of the present study was to compare the use of endoscopic ultrasound, CT and mangafodipir trisodium-enhanced MRI for the staging of pancreatic malignancy, particularly with respect to determining resectability prior to surgery. Twenty-seven patients referred for the investigation of a suspected pancreatic malignancy were entered into the trial. All patients had contrast-enhanced CT, gadolinium and mangafodipir trisodium-enhanced MRI, and endoscopic ultrasound (EUS). Images were assessed for nodal staging, tumour staging and resectability for each investigation, and the results compared with findings at surgery. The results for the accuracy of MRI, CT and EUS, in detecting T4 disease versus T3 or lower was 78, 79 and 68%, respectively; nodal involvement was 56, 63 and 69%, respectively; and overall resectability (including the T stage, presence of involved nodes and metastases) was 83, 76 and 63%, respectively. There was no significant difference demonstrated between the three tests. The present study suggests that for patients referred for investigation and staging of pancreatic malignancy, EUS and MRI scanning convey little advantage over contrast-enhanced CT. Furthermore, although mangafodipir trisodium improved the conspicuity of pancreatic tumours, it has little influence on T staging.

We examined the association between insulin resistance and adipose tissue compartments in overweight/obese men. Total intra-abdominal, intraperitoneal, retroperitoneal, total subcutaneous, anterior subcutaneous and posterior subcutaneous abdominal adipose tissue (PSAAT) masses (total intra-abdominal fat TIAATM, IPATM, RPATM, TSAATM, ASAATM and PSAATM, respectively) were quantified in 51 overweight/obese men using magnetic resonance imaging (MRI). Total adipose tissue mass (TATM) was also determined using bioelectrical impedance. Insulin resistance was estimated by homeostasis model assessment (HOMA) score. In univariate regression analysis, all fat compartments, with the exception of RPATM, were significantly and positively correlated with the HOMA score. The positive correlation between HOMA score and both IPATM and anterior subcutaneous adipose tissue mass was independent of obesity status. After adjusting total for TATM, only IPATM was significantly correlated with HOMA score (partial r=0.38, P

Arterial embolization hyperthermia (AEH) consists of arterially embolizing liver tumours with ferromagnetic particles that generate hysteretic heating on exposure to an alternating magnetic field. A critical component of AEH is the concentration and distribution of ferromagnetic particles in the normal hepatic parenchyma (NHP), as well as in the tumour tissue. If the distribution of particles in NHP is heterogeneous, with areas of high concentration, then unwanted areas of necrosis may result during AEH. Using an in vivo rabbit liver tumour model, this study showed that hepatic arterial infusion of ferromagnetic particles does indeed result in a heterogeneous distribution of iron in NHP. The radiological technique of magnetic resonance imaging (MRI) was then evaluated as a potential tool for non-invasively and prospectively determining the concentration and distribution of particles within the hepatic tumour and NHP following hepatic arterial infusion. A preliminary in vitro experiment showed that although the concentration of iron within the tumour tissue (1.92-3.50 mg of iron per gram of tissue) was too great to measure, MRI was able to accurately determine the lower iron concentration (0.10-0.53 mg of iron per gram of tissue) in NHP. Further work is needed to evaluate MRI under in vivo conditions. If successful, MRI could become an important component of an emerging novel treatment for advanced hepatic malignancies.

Lumbar nerve root avulsion is a rarely seen clinical entity that may complicate major trauma. The majority of previously reported cases have associated pelvic or lumbar vertebral fractures. Two cases of traumatic pseudomeningoceles at the lumbar level with associated avulsions of the lumbar nerve roots are presented. Both patients were involved in high velocity motor vehicle accidents. Case 1 had associated pelvic fractures but no spinal fractures and, interestingly, case 2 had no fractures of the spine or pelvis. The value of MRI in making the diagnosis is demonstrated.

SUMMARY Proton MR spectroscopy has been used to characterize the spectroscopic profiles of a wide variety of neurological disease processes. In particular, the spectroscopic characteristics of a range of focal intracranial mass lesions have been described. The use of proton MR spectroscopy has until recently been restricted to major research centres with high-field MR scanners. The spectroscopic findings in a number of illustrative cases imaged at Royal Perth Hospital using a 1-T scanner are described here. The cases illustrated in the present paper confirm the clinical utility of proton MR spectroscopy as a supplement to conventional MR in routine radiological practice.

Flexion and extension movements or positions have been advocated in the treatment of various forms of low back dysfunction due to the potential pain relieving effects attributed to displacements of the intervertebral disc (IVD). Objective in vivo determination of the segmental behaviour of the disc to contrasting positions has until recently been difficult. Magnetic resonance imaging (MRI) was used in this study to evaluate the influence of sagittal plane positions on lumbar IVD height and nucleus displacement in a small asymptomatic population.T2-weighted sagittal plane images from L1 to S1 were obtained from 10 subjects (mean age: 30+/-5 years) positioned supine in lumbar flexion, followed by extension. Changes in disc height and localization of nucleus position (determined by peak MRI signal intensity) between the two positions were calculated. Discs were classified for degenerative changes using a semi-quantitative grading scale. The mean range of lumbar sagittal movement achieved in the MRI was 44 degrees (range: 22-77 degrees ). Between flexion and extension, a significant increase in measured anterior disc height of 1.1 mm (P

A 23-year-old male involved in a high-speed collision acquired, among other injuries, a wide fracture distraction at C2/C3. Reduction was delayed by an enlarging vertebral artery pseudo-aneurysm at the site of injury which was successfully treated by proximal endovascular occlusion with a detachable polymer-filled balloon. A traumatic arachnoid cyst or pseudomeningocele was also demonstrated at the injury site but intervention was not required. The treatment and outcome of these three uncommon injuries in the literature is reviewed and discussed. Given the severity of the injury, the absence of severe long-term neurological disability is notable.

SUMMARY A 60-year-old man presented with sudden onset of left shoulder pain followed 2 weeks later by the development of left shoulder girdle weakness. A clinical and electrophysiological diagnosis of subacute idiopathic brachial neuritis was made. The MRI features of subacute muscular denervation in this patient are discussed and the relevant literature reviewed.

The editorial by Wallin and Fladby highlights the clinical importance of white matter hyperintensities on magnetic resonance imaging as a marker of small vessel disease in elderly people.1 Prevalence ranges from 11-21% at age 64 …

The 3-D skeletal images obtained from reconstruction of CT scans and X-rays, and soft-tissue images produced by MRI, provide invaluable information of the internal and gross anatomy of the north-western marsupial mole (Notoryetes caurinus). The conical skull, which is quite thin-walled dorsally and anteriorly but strong in the basicranial region, has little evidence of the orbit or zygomatic arch, and the smoothly-curved posterior region has no sagittal or occipital crests. The vertebral column is remarkably strengthened, and in lateral view has an unusual flat-shape. The cervical vertebrae appear to be greatly compressed; 4 or 5 are completely fused (which is unique among marsupials). The thoracic vertebrae are fairly robust with large neural spines. The lumbar vertebrae are distinct, becoming large posteriorly towards the pelvis. The sacral vertebrae are greatly expanded in size and are fused with the pelvis. Particularly in the middle of the tail, the caudal vertebrae are greatly developed, with large transverse processes and chevron bones. The pectoral girdle is very anterior, with the shoulder articulation level with the anterior cervical vertebrae just behind the skull, and low on the side of the body. The humerus is robust, and the radius and ulna are very short. The bones of the pelvis are highly derived, and fused to sacral vertebrae. The epipubic bones are small and not ossified. An ossified patella is present and it has an unusual large triangular keel. The most apparent soft-tissue structure by MRI is a large amount of subcutaneous fat, particularly around the ventral surface of the pelvis but also dorsal to the pelvis and anteriorly around the shoulders. The major muscle groups are visible, but distinction between individual muscles is not possible except for the very large muscles of the thigh, upper arm and base of the tail. The muscles of the tail are strongly developed, more so ventrally than dorsally.