Ultrasound accuracy for brachial plexus pathology.

AIM: To determine (a) the accuracy of ultrasound in detecting brachial plexus pathology and (b) outline the advantages and limitations of ultrasound compared to MRI for imaging the brachial plexus. MATERIAL AND METHODS: cases with clinically suspected brachial plexus pathology were evaluated first by ultrasound, followed by MRI. Patients with prior brachial plexus imaging were excluded. The final diagnosis was based on a combination of ultrasound, MRI, clinical follow-up, and surgical findings. The accuracy of the ultrasound was assessed by comparing the ultrasound and the final diagnoses. The mean clinical follow-up time following ultrasound was 1.8 ± 1.4 years. RESULTS: Ninety-two (64%) of the 143 cases had normal brachial plexus ultrasound and MRI examinations. Fifty-one (36%) of 143 cases had brachial plexus pathology on MRI, comprising post-radiation fibrosis (n=25, 49%), nerve sheath tumor (n=11, 21%), traumatic injury (n=7, 14%), inflammatory polyneuropathy (n=4, 8%), malignant infiltration (n=2, 4%), desmoid fibromatosis (n=1,2%), and neuralgic amyotrophy (n=1, 2%). Overall diagnostic accuracy of ultrasound for brachial plexus pathology was 98% (140/143), with three discordant cases (neuralgic amyotrophy n=1, inflammatory neuropathy n=1, postradiation fibrosis n=1) regarded as normal on ultrasound assessment. Sensitivity, specificity, and positive and negative predictive value of ultrasound for identifying brachial plexus pathology were 94%, 100%, 100%, and 97%, respectively. CONCLUSION: Ultrasound identifies brachial plexus pathology with high accuracy and specificity, showing comparable diagnostic efficacy to MRI. Ultrasound can serve as an effective first-line imaging investigation for suspected brachial plexus pathology.

Ultrasound-guided lymph node sampling: accuracy of FNAC, end-cutting (Franseen), and side-cutting (Temno) needle biopsy techniques.

AIM: To compare technical success, diagnostic accuracy, and histological yield of fine-needle aspiration cytology (FNAC), side-cutting (Temno) needle biopsy, and end-cutting (Franseen) needle biopsy for ultrasound-guided sampling of groin and axillary lymph nodes. MATERIALS AND METHODS: A total of 270 abnormal groin and axillary nodes were sampled using one of the three techniques. Nodes with a maximum length of <2.5 cm underwent FNAC or Franseen biopsy, while nodes >2.5 cm underwent Temno biopsy. Mean size of nodes sampled by FNAC (21.2 mm) and Franseen (19.7 mm) were similar while nodes sampled by Temno were larger (34.4 mm, p<0.0001). RESULTS: Technical success rates of FNAC (82/93, 88%), Franseen (105/111, 95%), and Temno (59/66, 89%) biopsies were similar (p>0.05 for all). Lymphoid tissue yield by FNAC (mean total area 1.51 mm2) was less than that by Franseen (7.14 mm2, p=0.002) or Temno biopsy (19.44 mm2, p<0.0001). Diagnostic accuracy for malignancy was lower for FNAC (22/30, 73%) than Franseen (25/26, 96%, p=0.02) or Temno biopsy (32/32, 100%, p=0.002). For malignant nodes, determining the likely organ of origin was also lower for FNAC (7/30, 23%) than Franseen (19/26, 73%, p=0.0002) or Temno biopsy (29/32, 91%, p<0.0001), with a similar pattern observed in the identification of lymphoma. CONCLUSION: For similarly sized nodes, Franseen biopsy provided more lymphoid material, a higher diagnostic accuracy for malignancy including lymphoma, and better identification of the likely organ of origin than FNAC. Routine use of Franseen biopsy is advocated rather than FNAC for percutaneous sampling of lymph nodes not suitable for side-cutting needle biopsy.

MRI of carpal tunnel syndrome: before and after carpal tunnel release.

Carpal tunnel syndrome (CTS) is the most common peripheral nerve entrapment syndrome. Magnetic resonance imaging (MRI) is increasingly used to diagnose CTS, exclude secondary causes of CTS, and investigate patients with persistent symptoms after carpal tunnel release. Median nerve compression may also be either subclinical in the early stages or present with atypical symptoms. Radiologists are therefore not infrequently the first to alert clinicians as to the possibly of subclinical or atypical CTS. This review shows the normal and abnormal appearances of the carpal tunnel before and after CTR.

Comparison of bone structure and microstructure in the metacarpal heads between patients with psoriatic arthritis and healthy controls: an HR-pQCT study.

Human cadaveric study has indicated that the metacarpal head (MCH) is intracapsular in location. We hypothesized that exposure to the intra-articular inflammatory milieu in psoriatic arthritis (PsA) will lead to bone loss in the MCH. INTRODUCTION: To compare the bone structure and microstructure in the MCH between patients with PsA and healthy controls by high-resolution peripheral quantitative CT (HR-pQCT), and to ascertain factors associated with bone loss in PsA patients. METHODS: Sixty-two PsA patients without joint destruction and 62 age-, gender-, and body mass index-matched healthy subjects underwent HR-pQCT imaging of the second and third MCH (MCH 2&3). The number and volume of bone erosion and enthesiophytes, as well as volumetric bone mineral density (vBMD) and microstructure at the MCH 2&3, were recorded. Correlation analysis and multivariable linear regression models were used to determine the association of demographic and disease-specific variables with compromised bone structure and microstructure in PsA. RESULTS: At the MCH 2&3, bone erosion (p = 0.003) and enthesiophyte (p = 0.000) volumes in PsA patients were significantly larger than healthy controls. In PsA patients, older age was associated with a larger erosion and enthesiophyte volume. Concerning the mean vBMD and microstructure at the MCH 2&3, PsA patients had significantly lower mean vBMD (average vBMD - 6.9%, trabecular vBMD - 8.8%, peri-trabecular vBMD - 7.7%, meta-trabecular vBMD - 9.8%), trabecular bone volume fraction (- 8.8%), and trabecular thickness (- 8.1%) compared with control subjects. Multivariable regression analysis revealed that older age and a higher C-reactive protein level were associated with trabecular bone loss. CONCLUSIONS: PsA patients had a higher burden of bone damages (erosions and enthesiophytes) and trabecular bone loss compared with healthy control at the MCH. Inflammation contributed to the deterioration in trabecular microstructure in these patients.

Elderly males with or without existing osteoporotic vertebral fracture have much lower future vertebral fracture risk than elderly females: the MrOS (Hong Kong) year-4 follow-up spine radiograph study.

MrOS (Hong Kong)'s year-4 follow-up shows, for subjects at baseline without vertebral deformity (VD) and endplate or/and cortex fracture (ECF), the VD progression/new VD rate during follow-up in males was half of our paired MsOS (Hong Kong) study's results. For those with VD or ECF, the VD progression/new VD was less than one sixth of females' rate. INTRODUCTION: This study documents MrOS (Hong Kong)'s year-4 follow-up, and the results are compared with the MsOS (Hong Kong) study. Of elderly females with Genant's grade-0, -1, -2, and -3 VD, at year-4 follow-up, 4.6%, 8%, 10.6%, and 28.9% had at least one VD progression or incident VD, respectively. METHODS: Spine radiographs of 1500 Chinese males with baseline (mean age 71.7 years, range 65-91 years) and year-4 follow-up were evaluated according to Genant's VD criteria and ECF (non-existent, ECF0; or existent, ECF1). Grade-2 VDs were divided into mild (VD2m, 25-34% height loss) and severe (VD2s, 34-40% height loss) subgroups. Study subjects were graded into eight categories: VD0/ECF0, VD1/ECF0, VD2m/ECF0, VD0/ECF1, VD1/ECF1, VD2m/ECF1, VD2s/ECF1, and VD3/ECF1. With an existing VD, a further height loss of ≥ 15% was a VD progression. A new VD incident was a change from grade-0 to grade-2/3, or to grade-1 with ≥ 10% height loss. RESULTS: Of subjects with Genant's grade-0, 2.05% (25/1219) developed at least one VD progression or/and new VD, while of subjects with Genant's grade-1, -2, and -3 VD, only 2% (3/149), 3.1% (3/96), and 2.8% (1/36) developed at least one VD progression/new VD, respectively. Among the three ECF0 groups, there was a significant difference in new ECF incidence, with VD0/ECF0 being the lowest and VD2m/ECF0 being the highest. CONCLUSION: VD progression/new VD is much less common in elderly men than in elderly women. Vertebrae with VD had a higher risk of developing ECF.

Osteoporotic vertebral deformity with endplate/cortex fracture is associated with higher further vertebral fracture risk: the Ms. OS (Hong Kong) study results.

Compared with vertebrae without deformity, vertebrae with mild/moderate deformity have a higher risk of endplate or/and cortex fracture (ecf). Compared with subjects without ecf, subjects with ecf are at a higher risk of short-term (4-year period) deformity progression and new incident deformity. INTRODUCTION: The progression and incidence of osteoporotic vertebral deformity/fracture (VD/VF) in elderly Chinese females remain not well documented. METHODS: Spine radiographs of 1533 Chinese females with baseline and year-4 follow-up (mean age 75.7 years) were evaluated according to Genant's VD criteria and endplate/cortex fracture (non-existent: ecf0 or existent: ecf1). Grade-2 VDs were divided into mild (vd2m, 25-34% height loss) and severe (vd2s, 34-40% height loss) subgroups. According to their VD/VF, subjects were graded into seven categories: vd0/ecf0, vd1/ecf0, vd2m/ecf0, vd1/ecf1, vd2m/ecf1, vd2s/ecf1, and vd3/ecf1. With an existing VD, a further height loss of ≥ 15% was a VD progression. A new incident VD was a change from grade-0 to grade-2/3 or to grade-1 with ≥ 10% height loss. RESULTS: Of subjects with Genant's grades 0, - 1, - 2, and - 3 VD, at follow-up, 4.6%, 8%, 10.6%, and 28.9% had at least one VD progression or new incident VD respectively. Among the three ecf0 groups, there was no difference in VD progression or new VD; while there was a significant difference in new ecf incidence, with vd0/ecf0 being lowest and vd2m/ecf0 being highest. Vd1/ecf0 and vd2m/ecf0 vertebrae had a higher risk of turning to ecf1 than vd0/ecf0 vertebrae. If vd1/ecf0 and vd2m/ecf0 subjects were combined together (range 20-34% height loss) to compare with vd1/ecf1 and vd2m/ecf1 subjects, the latter had significantly higher VD progression and new VD rates. CONCLUSION: Vertebrae with grade-1/2 VDs had a higher risk of developing ECF. Subjects with pre-existing ECFs had a higher risk of worsening or new vertebral deformities.

Ultrasound carpal tunnel syndrome: additional criteria for diagnosis.

AIM: To define the usefulness of the cross-sectional area (CSA) of the median nerve distal to the carpal tunnel in addition to other established common parameters in the diagnosis of carpal tunnel syndrome (CTS). MATERIALS AND METHODS: Forty-four wrists from 24 symptomatic CTS patients and 32 wrists from 17 asymptomatic volunteers were evaluated by ultrasound. The CSA of the median nerve was measured at four pre-selected levels, i.e., proximal, inlet, outlet, and distal to the carpal tunnel. The flattening ratio, intraneural vascularity, neural fasciculation, and retinacular palmar bowing were also assessed. RESULTS: Significant differences were found between the CTS and control groups for median nerve CSA proximal and distal (p<0.001) to the tunnel as well as retinacular bowing (p<0.001). Using the receiver operating characteristic (ROC) curve, the sensitivity, specificity, and accuracy of using a cut-off of >14 mm2 of CSA proximal and distal to the tunnel were 75%, 87.5%, 86.8% and 63.6%, 100%, 78.9%, respectively. Using either CSA proximal or distal to the tunnel or bowing retinaculum at the outlet >1 mm yielded a sensitivity, specificity, and accuracy of 100%, 84.3% and 93.4%, respectively. CONCLUSION: The median nerve CSA proximal and distal to the carpal tunnel and bowing of the retinaculum at the outlet are helpful in diagnosis of CTS.

Cortical thinning and progressive cortical porosity in female patients with systemic lupus erythematosus on long-term glucocorticoids: a 2-year case-control study.

UNLABELLED: In this study, we characterized longitudinal changes of volumetric bone mineral density and cortical and trabecular microstructure at the distal radius using HR-pQCT in female systemic lupus erythematosus (SLE) patients on long-term glucocorticoids. Cortical thinning and increased cortical porosity are the major features of longitudinal microstructural deterioration in SLE patients. INTRODUCTION: The study aims to characterize longitudinal changes of volumetric bone mineral density (vBMD) and bone microstructure at distal radius in female systemic lupus erythematosus (SLE) patients on long-term glucocorticoids. METHODS: This 2-year case-control study consisted of 166 premenopausal subjects (75 SLE patients and 91 controls) and 79 postmenopausal subjects (44 SLE patients and 35 controls). We obtained areal BMD (aBMD) by dual-energy X-ray absorptiometry at multiple skeletal sites and indices of vBMD and microstructure at distal radius by high-resolution peripheral quantitative computed tomography (HR-pQCT) at baseline, 12 and 24 months. RESULTS: In either premenopausal or postmenopausal subjects, changes in aBMD did not differ between patients and controls except that decrease in aBMD at total hip at 24 months in premenopausal patients was significantly higher. In premenopausal subjects, decrease in cortical area (-0.51 vs. -0.06 %, p = 0.039) and thickness (-0.63 vs. 0.02 %, p = 0.031) and increase in cortical porosity (21.7 vs. 7.16 %, p = 0.030) over study period were significantly larger in patients after adjustment of age and body mass index. Decreased in trabecular vBMD was significantly less (-0.63 vs. -2.32 %, p = 0.001) with trabecular microstructure better maintained in patients. In postmenopausal subjects, decrease in cortical vBMD (-2.66 vs. -1.56 %, p = 0.039) and increase in cortical porosity (41.6 vs. 16.3 %, p = 0.021) were significantly higher in patients, and there was no group-wise difference in change of trabecular microstructure. CONCLUSION: Longitudinal microstructural deterioration in SLE is characterized by cortical thinning and increased cortical porosity. Cortical bone is an important source of bone loss in SLE patients on glucocorticoids.

Density, structure, and strength of the distal radius in patients with psoriatic arthritis: the role of inflammation and cardiovascular risk factors.

UNLABELLED: We investigated the densitometric and microstructural features of the distal radius in psoriatic arthritis (PsA) patients using high-resolution peripheral quantitative computed tomography. PsA patients have unique bone microstructural deficits, manifested as lower cortical bone density and higher cortical porosity, which are associated with a propensity to bone fragility. INTRODUCTION: The aim of this study was to investigate the densitometric, geometric, microstructural, and biomechanical features of the distal radius in psoriatic arthritis (PsA) patients. METHODS: This study cohort consisted of 53 PsA patients (24 males and 29 females), with an average age of 53.1 years and 53 gender- and age-matched controls. Areal bone mineral density (aBMD) of the hip, lumbar spine, and ultradistal radius was measured by dual-energy X-ray absorptiometry. High-resolution peripheral quantitative computed tomography (HR-pQCT) was performed at the distal radius to obtain measures of volumetric BMD (vBMD), microstructure, and derived biomechanical indices. RESULTS: There were no significant between-group differences in aBMD at the femoral neck, total hip, and ultradistal radius, while aBMD at the lumbar spine was significantly higher in patients. The only indices indicating compromised bone quality in PsA patients were related to cortical bone quality. Cortical vBMD were -3.8% significantly lower, while cortical pore volume, porosity index, and pore diameter were 108, 79.5, and 8.6%, respectively, significantly higher in patients. Cortical stress was marginally lower (-1.3%, p = 0.077) in patients with stress significantly more unevenly distributed (4.9%, p = 0.035). Endocortical perimeter and cortical pore volume were significantly higher in patients with vertebral fracture. Deficits in cortical bone quality were associated with indices of disease activity/severity and were more prominent in patients with type 2 diabetes mellitus or hypertension. CONCLUSIONS: There is an intertwined relationship between chronic inflammation, cardiovascular risk factors, and bone loss in PsA. PsA patients seem to have unique bone microstructural deficits which are associated with a propensity to bone fragility.

Incidence of and risk factors for non-vertebral and vertebral fracture in female Chinese patients with systemic lupus erythematosus: a five-year cohort study.

OBJECTIVE: The objective of this paper is to investigate the incidence of both non-vertebral and vertebral fracture in female patients with systemic lupus erythematosus (SLE) and to identify risk factors for incident fracture. METHODS: In a five-year prospective study of 127 female Chinese SLE patients with an average age of 46.9 years (SD: 10.1 years), information on potential risk factors, including demographics, clinical data and bone mineral density (BMD) at lumbar spine and hip by dual-energy X-ray absorptiometry was collected at baseline. At follow-up, participants reported incident non-vertebral fracture during the study period. Semi-quantitative analysis was used to determine incident vertebral fracture on lateral thoracic and lumbar radiographs, defined as any vertebral body graded normal at baseline and at least mildly deformed (20%-25% reduction or more in any vertebral height) at follow-up. RESULTS: Nine incident non-vertebral fractures occurred in eight patients during the study period. Six patients had one or more incident vertebral fractures. The incidence of non-vertebral and vertebral fracture was 1.26 and 0.94 per 100 patient-years, respectively. In multivariate logistic analyses, independent variables associated with incident non-vertebral fracture were duration of glucocorticoid use and prevalent lumbar spine osteoporosis, while risk factors associated with incident vertebral fracture were higher organ damage and prevalent lumbar spine osteoporosis. CONCLUSIONS: The incidence of fracture in SLE patients is lower than the prevalence reported in cross-sectional studies. Lumbar spine BMD appears to have a stronger relationship with incident fracture than hip BMD. This warrants further investigation regarding the optimal site of BMD measurement when predicting fracture risk in SLE patients.

Factors affecting the relationship between quantitative polymerase chain reaction (qPCR) and culture-based enumeration of Enterococcus in environmental waters.

AIMS: To determine the extent to which discrepancies between qPCR and culture-based results in beach water quality monitoring can be attributed to: (i) within-method variability, (ii) between-method difference within each method class (qPCR or culture) and (iii) between-class difference. METHODS AND RESULTS: We analysed 306 samples using two culture-based (EPA1600 and Enterolert) and two qPCR (Taqman and Scorpion) methods, each in duplicate. Both qPCR methods correlated with EPA1600, but regression analyses indicated approximately 0·8 log10 unit overestimation by qPCR compared to culture methods. Differences between methods within a class were less than half of this and were minimal for between-replicate within a method. Using the 104 Enterococcus per 100 ml management decision threshold, Taqman qPCR indicated the same decisions as EPA1600 for 87% of the samples, but indicated beach posting for unhealthful water when EPA1600 did not for 12% of the samples. After accounting for within-method and within-class variability, 8% of the samples exhibited true between-class discrepancy where both qPCR methods indicated beach posting while both culture methods did not. CONCLUSION: Measurement target difference (DNA vs growth) accounted for the majority of the qPCR-vs-culture discrepancy, but its influence on monitoring application is outweighed by frequent incorrect posting with culture methods due to incubation time delay. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first study to quantify the frequency with which culture-vs-qPCR discrepancies can be attributed to target difference - vs - method variability.

The functional muscle-bone unit in subjects of varying BMD.

SUMMARY: This study used the "functional muscle-bone unit" concept to investigate muscle-bone interaction of the lumbar spine in subjects of varying bone mineral density. It was found that unit bone mass corresponded to a relatively more muscle mass in subjects with reduced bone mineral density, indicating a relatively higher mechanical load from muscles exerted on trabecular bone. INTRODUCTION: Bone is an architecturally adaptive tissue which responds to mechanical loading. This study is proposed to use "functional muscle-bone unit" to reflect this muscle-bone interaction at spine in subjects with different bone mineral density. METHODS: The study was carried out in young normal subjects (21 females; age, 29 ± 3) and elderly subjects (155 females; age, 73 ± 3.9) with varying bone mineral density. Cross-sectional area of paravertebral muscle groups was measured in MR images to indicate the muscle mass, while the bone mineral content by dual X-ray absorptiometry was used to represent the bone mass. The functional muscle-bone unit was calculated as the ratio between the bone mass to muscle mass. RESULTS: It showed that with aging, the muscle mass decreased with the bone mass losing. However, more pronounced reduction was found in bone mass than in muscle mass in the subjects with lower bone mineral density. CONCLUSIONS: Muscle-bone interaction was changed in elderly, especially in those with osteoporosis. Unit bone mass corresponded to a higher muscle mass in subjects with reduced bone mineral density than those normal subjects. This may be contributory to the occurrence of nontraumatic vertebral fractures in elderly subjects with reduced bone mineral density.

SLE disease per se contributes to deterioration in bone mineral density, microstructure and bone strength.

OBJECTIVE: The objective of this report is to assess the effect of systemic lupus erythematosus (SLE) disease itself on deterioration of bone mineral density (BMD), microstructure and bone strength. METHOD: Thirty age-matched SLE patients on long-term glucocorticoids (GC) (SLE/GC), 30 SLE patients without GC (SLE/non-GC) and 60 healthy controls were examined. Areal BMD (aBMD) was measured by dual-energy X-ray absorptiometry. Bone geometry, volumetric BMD (vBMD), and architectural parameters at the nondominant distal radius were assessed by high-resolution peripheral quantitative computed tomography (HR-pQCT). Bone strength was estimated by HR-pQCT-based micro-finite element analysis. RESULTS: Adjusted for menopausal status and adjusted calcium level, when compared with controls, SLE/non-GC patients had significantly lower aBMD at femoral neck and total hip, and diminished radial total vBMD, cortical area, vBMD and thickness, respectively, by 8.3%, 8%, 2.7% and 9.2%, as well as significant compromised bone strength (stiffness, failure load and apparent modulus) by 8.3%, 9.1% and 9.5%, respectively. Similar alterations were also found in SLE/GC patients when compared to controls. In the premenopausal subgroup analysis, when compared with controls, total hip aBMD and radial cortical area were significantly lower in SLE/non-GC patients, and cortical area and thickness were significantly deficit in SLE/GC patients. However, no significant difference in any bone variables was present between SLE/GC and SLE/non-GC patients in the entire cohort or in the premenopausal subgroup. CONCLUSION: SLE disease per se contributes to the deterioration in bone density, cortical microstructure and bone strength. This might help to explain the considerably higher fracture risk seen in SLE patients.

Prevalence and risk factors of radiographic vertebral fractures in elderly Chinese men and women: results of Mr. OS (Hong Kong) and Ms. OS (Hong Kong) studies.

UNLABELLED: This study investigated the prevalence of radiographic vertebral fractures using Genant's semiquantitative (SQ) scoring system in elderly Chinese men (n = 2,000; mean age, 72.4 years) and women (n = 2,000; mean age, 72.6 years). Vertebral deformities had similar prevalence in elderly men (14.9 %) and women (16.5 %). Majority of the deformities in men were mild (9.9 %, grade = 1). The prevalence of vertebral fractures (grade ≥ 2) was 5.0 % among men and 12.1 % among women. INTRODUCTION: Vertebral fracture is a serious consequence of osteoporosis and is often under-diagnosed. Researches on different ethnicities and territories to estimate the prevalence of vertebral fractures and to identify the risk factors are necessary. METHODS: Mr. OS (Hong Kong) and Ms. OS (Hong Kong) represent the first large-scale cohort studies ever conducted on bone health in elderly Chinese men (n = 2,000) and women (n = 2,000). The current study investigated the prevalence of radiographic vertebral fractures in these subjects using Genant's SQ scoring system and identified risk factors for vertebral fractures. RESULTS: The radiographs of all men (mean age, 72.4 years) and women (mean age, 72.6 years) were obtained. Six hundred twenty-seven subjects (15.7 %) had at least one vertebral deformity (SQ grade ≥ 1), including 297 men (14.9 %) and 330 women (16.5 %, p = 0.151). Three hundred forty-two participants (8.6 %) were defined as having at least one vertebra fracture (SQ grade ≥ 2), consisted of 100 men (5.0 %) and 242 women (12.1 %, p < 0.001). Older age, lower bone mineral density, lower physical activity, lower grip strength, fracture history, and low back pain were significantly associated with higher vertebral fracture rate for both men and women. CONCLUSION: Vertebral deformity had similar prevalence in older men and women, while vertebral fracture was more common in women. Majority of deformities in men was mild. The vertebral deformity prevalence of women from this study is similar to previous reports of other East Asian women and Latin American women.

Alterations of bone geometry, density, microarchitecture, and biomechanical properties in systemic lupus erythematosus on long-term glucocorticoid: a case-control study using HR-pQCT.

UNLABELLED: Compared to controls, HR-pQCT at distal radius of SLE patients on chronic glucocorticoid (SLE/GC) revealed reduced bone area, vBMD, deteriorated microarchitecture, and unevenly distributed stresses limited to cortical bone. Despite similar trabecular quality, whole bone strength decreased in patients. These alterations may partly explain high fracture rates in SLE/GC. INTRODUCTION: To assess bone geometric, densitometric, microarchitectural, and biomechanical properties in patients with systemic lupus erythematosus (SLE) on long-term glucocorticoid (GC) (SLE/GC) as compared with healthy controls. METHODS: A total of 180 female SLE patients and 180 healthy controls were in this cross-sectional study to assess areal bone mineral density (aBMD) by dual-energy X-ray absorptiometry. High-resolution peripheral quantitative computed tomography (HR-pQCT) and microfinite element analysis (µFEA) was performed at distal radius. RESULTS: In addition to significantly lower aBMD at femoral neck, total hip and lumbar spine, cortical area, average volumetric BMD (vBMD) and cortical vBMD also significantly reduced by 5.3, 5.7, to 1.9 % in SLE patients, respectively. Deteriorations of cortical microarchitecture were pronounced in patients, with 6.3 % reduction in cortical thickness and 13.6 % higher in cortical porosity. Local stresses were more unevenly distributed through cortical bone in patients. SLE/GC patients had decreased whole bone stiffness, estimated failure load, and apparent modulus. Parameters related to trabecular bone density and microarchitecture were comparable between patients and controls. CONCLUSION: In SLE/GC patients, despite a reduction in bone area, vBMD and deteriorated microarchitecture and unevenly distributed stresses limited to the cortical compartment, whole bone strength decreased. HR-pQCT and µFEA were promising in elucidating the potential underlying pathophysiology of bone loss and propensity to fracture in SLE/GC and provide us additional information about alterations of bone quality which might better predict fracture risk beyond aBMD in SLE/GC.

Vertebral body corner oedema vs gadolinium enhancement as biomarkers of active spinal inflammation in ankylosing spondylitis.

OBJECTIVE: To investigate the relative performance of T(2) weighted short tau inversion-recovery (STIR) and fat-suppressed T(1) weighted gadolinium contrast-enhanced sequences in depicting active inflammatory lesions in ankylosing spondylitis (AS). METHODS: Whole-spine MRI was performed on 32 patients with AS, who participated in a clinical trial of infliximab treatment, by STIR and contrast-enhanced sequences at baseline and after 30 weeks. The AS spine MRI-activity (ASspiMRI-a) scoring method was used. The images from these two imaging techniques were evaluated separately by two independent readers. RESULTS: For the pre-treatment lesion status, the intraclass correlation coefficients comparing STIR readings and contrast-enhanced readings were 0.69±0.23 for Reader 1 and 0.65±0.21 for Reader 2. At baseline, the mean ASspiMRI-a score was 15.4% and 17.7% higher for contrast-enhanced images than for STIR images for Reader 1 and Reader 2, respectively. After infliximab treatment, Reader 1 rated an ASspiMRI-a score reduction of 50.8±33.6% and 25.3±35.3% for STIR images and contrast-enhanced images, respectively, whereas Reader 2 rated an ASspiMRI-a score reduction of 42.4±50.4% and 32.9±35.6% for STIR images and contrast-enhanced images, respectively. CONCLUSION: While both contrast-enhanced and STIR sequences showed sensitivity to change over a short period of time after infliximab treatment, these two sequences may reflect different disease mechanisms.

Effectiveness of qPCR permutations, internal controls and dilution as means for minimizing the impact of inhibition while measuring Enterococcus in environmental waters.

AIMS: Draft criteria for the optional use of qPCR for recreational water quality monitoring have been published in the United States. One concern is that inhibition of the qPCR assay can lead to false-negative results and potentially inadequate public health protection. We evaluate the effectiveness of strategies for minimizing the impact of inhibition. METHODS AND RESULTS: Five qPCR method permutations for measuring Enterococcus were challenged with 133 potentially inhibitory fresh and marine water samples. Serial dilutions were conducted to assess Enterococcus target assay inhibition, to which inhibition identified using four internal controls (IC) was compared. The frequency and magnitude of inhibition varied considerably among qPCR methods, with the permutation using an environmental master mix performing substantially better. Fivefold dilution was also effective at reducing inhibition in most samples (>78%). ICs were variable and somewhat ineffective, with 54-85% agreement between ICs and serial dilution. CONCLUSIONS: The current IC methods appear to not accurately predict Enterococcus inhibition and should be used with caution; fivefold dilution and the use of reagents designed for environmental sample analysis (i.e. more robust qPCR chemistry) may be preferable. SIGNIFICANCE AND IMPACT OF THE STUDY: Suitable approaches for defining, detecting and reducing inhibition will improve implementation of qPCR for water monitoring.

Compromised perfusion in femoral head in normal rats: distinctive perfusion MRI evidence of contrast washout delay.

OBJECTIVES: The femoral head is prone to osteonecrosis. This study investigated dynamic contrast-enhanced (DCE) MRI contrast washout features of the femoral head and compared the data with data from other bony compartments in normal rats. METHODS: 7-month-old Wistar rats were used. DCE MRI of the right hip (n=18), right knee (n=12) and lumbar spine (n=10) was performed after an intravenous bolus injection of Gd-DOTA (0.3 mmol kg(-1)). Temporal resolution was 0.6 s for hip and spine, and 0.3 s for knee. The total scan duration was 8 min for hip and spine, and 4.5 min for knee. The regions of interest for enhancement measurement included femoral head, proximal femoral diaphysis, distal femoral diaphysis and epiphysis, proximal tibial epiphysis and diaphysis, and lumbar vertebrae L1-5. RESULTS: Femoral head showed no enhancement signal decay during the DCE MRI period, while all other bony compartments showed a contrast washin phase followed by a contrast washout phase. In the knee joint, the contrast washout of the proximal tibia diaphysis was slower that of other bony compartments of the knee. CONCLUSION: Based on the evidence of delayed contrast washout, this study showed that blood perfusion in the femoral head could be compromised in normal rats.

Method repeatability for measuring Enterococcus in southern California beach sands.

AIMS: A recent study that evaluated 22 methods for enumerating faecal indicator bacteria in sand recommended standardization to a preferred method, but all researchers involved in that study had extensive experience in processing sand samples. The purpose of this study was to evaluate how well the recommended method can be transferred to laboratories without such experience. METHODS AND RESULTS: Eight southern California laboratories that rarely measure bacteria in sand processed six sand and three water samples in replicates to assess repeatability. Among-laboratory variability was found to be less than within-laboratory variability, with no significant differences in results among any of the laboratories. Moreover, within-laboratory variability was comparable between the sand and water samples, indicating that the elution procedure added little additional method error even when performed by laboratories without prior experience. CONCLUSIONS: The simple extraction method for enumerating Enterococcus in beach sands was easily transferable to and repeatable among laboratories with little or no prior experience. SIGNIFICANCE AND IMPACT OF THE STUDY: The demonstrated success of technology transfer will further demonstrate the success of method standardization and adoption, aiding in understanding of how sands affect surface water quality.

Relationship between gender, bone mineral density, and disc degeneration in the lumbar spine: a study in elderly subjects using an eight-level MRI-based disc degeneration grading system.

UNLABELLED: The study cohort comprised 196 females and 163 males. Lumbar spine bone mineral density (BMD) and magnetic resonance imaging (MRI) were acquired. Females had more severe disc degeneration than males. Lumbar spine lower BMD was associated with less severe disc degeneration. Lumbar disc spaces were more likely to be narrower when vertebral BMD was higher. INTRODUCTION: The purpose of this paper is to study the relationship between gender, BMD, and disc degeneration in the lumbar spine. METHODS: The study cohort comprised 196 females and 163 males (age range 67-89 years) with no age difference between the two groups. Lumbar spine BMD was measured with dual X-ray densitometry, and MRI was acquired at 1.5 T. A subgroup of 48 males had additional lumbar vertebral quantitative computerized tomography densitometry. Lumbar disc degeneration was assessed using a MRI-based eight-level grading system. RESULTS: Female subjects had more severe disc degeneration than male subjects. After removing age effect, a positive trend was observed between T-score and severity of lumbar disc degeneration. This was significant in female subjects while not significant in male subjects. Lumbar disc spaces were more likely to be narrowed when vertebral BMD was higher. These observations were more significant in the midlumbar region (L3/4 and L4/5) and less so at the thoracolumbar junction. CONCLUSION: Female subjects tended to have slightly more severe lumbar disc degeneration than male subjects. Lower lumbar spine BMD was associated with less severe disc degeneration.