Association of body mass index with knee cartilage damage in an asymptomatic population-based study.

BACKGROUND: Cartilage changes are an important early finding of osteoarthritis (OA), which can exist even before symptoms. Our objective was to determine the prevalence of knee cartilage damage on magnetic resonance imaging (MRI) in an asymptomatic population-based cross-sectional study and to evaluate the association of body mass index (BMI) with cartilage damage. METHODS: Subjects, aged 40-79 years, without knee pain (n = 73) were recruited as a random population sample and assessed for BMI (kg/m2), including current BMI (measured), past BMI at age 25 (self-reported) and change in BMI. Knee cartilage was scored semi-quantitatively (grades 0-4) on MRI. In primary analysis, cartilage damage was defined as ≥2 (at least moderate) and in a secondary analysis as ≥3 (severe). We also conducted a sensitivity analysis by dichotomizing current BMI as <25 vs. ≥25. Logistic regression was used to evaluate the association of each BMI variable with prevalent MRI-detected cartilage damage, adjusted for age and sex. RESULTS: Of 73 subjects, knee cartilage damage ≥2 and ≥3 was present in 65.4% and 28.7%, respectively. The median current BMI was 26.1, median past BMI 21.6, and median change in BMI was a gain of 2.8. For cartilage damage ≥2, current BMI had a non-statistically significant OR of 1.65 per 5 units (95% CI 0.93-2.92). For cartilage damage ≥3, current BMI showed a trend towards statistical significance with an OR of 1.70 per 5 units (95% CI 0.99-2.92). Past BMI and change in BMI were not significantly associated with cartilage damage. Current BMI ≥ 25 was statistically significantly associated with cartilage damage ≥2 (OR 3.04 (95% CI 1.10-8.42)), but not for ≥3 (OR 2.63 (95% CI 0.86-8.03)). CONCLUSIONS: MRI-detected knee cartilage damage was highly prevalent in this asymptomatic population-based cohort. We report a trend towards significance of BMI with cartilage damage severity. Subjects with abnormal current BMI (≥25) had a 3-fold increased odds of cartilage damage ≥2, compared to those with normal BMI. This study lends support towards the role of obesity in the pathogenesis of knee cartilage damage at an asymptomatic stage of disease.

Deep venous thrombosis identification from analysis of ultrasound data.

PURPOSE: The purpose of this research was to determine whether combined ultrasound- and sensor-based compressibility and augmented blood flow measures yielded better results for DVT detection than for the individual measures alone. METHODS: Twenty-six limbs from 19 patients were scanned using a sensorized ultrasound DVT screening system, and compressibility and flow measures were obtained at 125 locations. Results from conventional compression ultrasound examination were used as gold standard, with seven vessels (four patients) positive for DVT. A classification approach was used to combine the individual DVT measures per vessel and generate an optimal feature for every possible combination of individual measures. Sensitivity and specificity were calculated for the individual measures and for all combined measures, as was a usefulness criteria [Formula: see text] for measuring class separability. RESULTS: Seven optimal combined features were found with 100% sensitivity and 100% specificity, with the best combined feature having a [Formula: see text] value over two orders of magnitude greater than the best individual DVT measure. CONCLUSIONS: The proposed approach for DVT detection combines different aspects of thrombus detection in a novel way generating a quantifiable measure and outperforms any of the individual measures when used independently. All of the combined measures included the flow measure as well as the slope compressibility measure, which uses the magnitude of the force applied by the ultrasound probe, suggesting that these measurements provide important information when characterizing DVT.

Half-dose non-contrast CT in the investigation of urolithiasis: image quality improvement with third-generation integrated circuit CT detectors.

PURPOSE: The objective of this study is to establish the effect of third-generation integrated circuit (IC) CT detector on objective image quality in full- and half-dose non-contrast CT of the urinary tract. METHODS: 51 consecutive patients with acute renal colic underwent non-contrast CT of the urinary tract using a 128-slice dual-source CT before (n = 24) and after (n = 27) the installation of third-generation IC detectors. Half-dose images were generated using projections from detector A using the dual-source RAW data. Objective image noise in the liver, spleen, right renal cortex, and right psoas muscle was compared between DC and IC cohorts for full-dose and half-dose images reconstructed with FBP and IR algorithms using 1 cm(2) regions of interest. Presence and size of obstructing ureteric calculi were also compared for full-dose and half-dose reconstructions using DC and IC detectors. RESULTS: No statistical difference in age and lateral body size was found between patients in the IC and DC cohorts. Radiation dose, as measured by size-specific dose estimates, did not differ significantly either between the two cohorts (10.02 ± 4.54 mGy IC vs. 12.28 ± 7.03 mGy DC). At full dose, objective image noise was not significantly lower in the IC cohort as compared to the DC cohort for the liver, spleen, and right psoas muscle. At half dose, objective image noise was lower in the IC cohort as compared to DC cohort at the liver (21.32 IC vs. 24.99 DC, 14.7% decrease, p < 0.001), spleen (19.33 IC vs. 20.83 DC, 7.20% decrease, p = 0.02), and right renal cortex (20.28 IC vs. 22.98 DC, 11.7% decrease, p = 0.005). Mean obstructing ureteric calculi size was not significantly different when comparison was made between full-dose and half-dose images, regardless of detector type (p > 0.05 for all comparisons). CONCLUSIONS: Third-generation IC detectors result in lower objective image noise at full- and half-radiation dose levels as compared with traditional DC detectors. The magnitude of noise reduction was greater at half-radiation dose indicating that the benefits of using novel IC detectors are greater in low and ultra-low-dose CT imaging.

Comparison of lifts versus tape measure in determining leg length discrepancy.

OBJECTIVE: To evaluate the validity (accuracy) and reliability of 2 commonly used clinical methods, 1 indirect (lifts) and 1 direct (tape measure), for assessment of leg length discrepancy (LLD) in comparison to radiograph. METHODS: Twenty subjects suspected of having LLD participated in this study. Two clinical methods, 1 direct using a tape measure and 1 indirect using lifts, were standardized and carried out by 4 examiners. Difference in height of the femoral heads on standing pelvic radiograph was measured and served as the gold standard. RESULTS: The intraclass correlation coefficient assessing interobserver reliability was 0.737 for lifts and 0.477 for tape measure. The remainder of the analysis is based on the average of the measurements by the 4 examiners. Pearson correlation coefficients were 0.93 for the lifts and 0.75 for the tape measure method. Paired sample t tests showed difference in means of 2 mm (p = 0.051) for lifts and -5 mm (p = 0.007) for tape measure compared with radiograph. Sensitivity and specificity were 55% and 89% for lifts and 45% and 56% for tape measure, respectively, using > 5 mm as the definition for LLD. The wrong leg was identified as being shorter in 1 out of 20 subjects using lifts versus 7 out of 20 using tape measure. CONCLUSION: The indirect standing method of LLD measurement using lifts had superior validity, interobserver reliability, and specificity in comparison with radiograph over the direct supine method using tape measure. Both clinical methods underestimated LLD compared with radiograph.

Imaging of blunt vascular neck injuries: a review of screening and imaging modalities.

OBJECTIVE: We will review the epidemiology of blunt cerebrovascular injuries (BCVIs) and the rationale for screening. Current imaging modalities used to screen for BCVIs will be discussed with an emphasis on CT angiography. CONCLUSION: Screening for BCVIs can decrease rates of postinjury complications, such as stroke. The use of standardized screening criteria and the appropriate imaging modalities can allow early detection of BCVIs and effective intervention.

Imaging of blunt vascular neck injuries: a clinical perspective.

OBJECTIVE: We will review the common injuries and anatomic distributions of blunt cerebrovascular injuries (BCVIs) of the neck, explain the grading criteria, and discuss the corresponding management. Artifacts associated with BCVI on CT will also be examined. CONCLUSION: Identifying common injury patterns and anatomic distributions associated with BCVI can help decide the grade and management earlier and reduce the risk for potential complications. Recognizing the common artifacts associated with BCVI helps the reader successfully recognize a true BCVI.

Clinical utility of ultra high pitch dual source thoracic CT imaging of acute pulmonary embolism in the emergency department: are we one step closer towards a non-gated triple rule out?

OBJECTIVES/PURPOSE: Aim of this study was to retrospectively compare the image quality and the radiation dose of an ultra high pitch CT scan for the evaluation of pulmonary embolism and visualization of cardiac structures in comparison to our institution's standard pulmonary embolism protocol. METHOD AND MATERIALS: The study cohort consisted of 115 consecutive patients, 57 underwent CT pulmonary angiography on a dual source 128 slice scanner (Siemens Somatom Definition FLASH) via an ultra high pitch mode (Pitch 2.8) while 58 were scanned on a dual source 64 slice scanner (Siemens Somatom Definition Dual Source) with standard pitch (Pitch 0.9). Qualitative image assessment was determined by two blinded radiologists with 3 and 15 years' experience in chest and cardiac CT. Quantitative image assessment was determined by the signal to noise ratio (SNR) and contrast to noise ratio (CNR). Effective radiation dose was calculated via the product of the dose length product. RESULTS: For the ultra high pitch protocol, 14% (8/57) were positive for pulmonary embolus compared to 13.7% (8/58) for the standard pitch group. 98.2% of the ultra high pitch scans were diagnostic for pulmonary embolus vs. 94.8% of the standard protocol. Visualization of cardiac structures was significantly improved with the ultra high pitch protocol (p<0.0001). Significantly more lung parenchymal motion was observed on the standard protocol (p<0.0001). The mean pulmonary vessel attenuation, SNR, and CNR were not significantly different. The mean effective dose was lower for the ultra high pitch studies (4.09mSv±0.78 vs. 7.72mSv±2.60, p<0.0001). CONCLUSION: Ultra high pitch CT imaging for pulmonary embolus is a technique which has potential to assess motion free evaluation of most cardiac structures and proximal coronary arteries at lower radiation doses.

Dual-energy CT: a promising new technique for assessment of the musculoskeletal system.

OBJECTIVE: Dual-energy CT (DECT) characterizes the chemical composition of material according to its differential x-ray attenuation at two different energy levels. Applications of DECT in musculoskeletal imaging include imaging of bone marrow edema, tendons, and ligaments and the use of monoenergetic techniques to minimize metal prosthesis beam-attenuating artifacts. CONCLUSION: The most validated application of DECT is undoubtedly its noninvasive and highly specific ability for confirming the presence of monosodium urate deposits in the assessment of gout.

Frequency of bone marrow lesions and association with pain severity: results from a population-based symptomatic knee cohort.

OBJECTIVE: To evaluate the prevalence of bone marrow lesions (BML) and their association with pain severity in a population-based cohort of symptomatic early knee osteoarthritis (OA). METHODS: Subjects with knee pain (n = 255), age 40-79 years, were evaluated by radiograph and magnetic resonance imaging (MRI) and classified into OA stages: no OA (NOA), preradiographic OA (PROA), and radiographic OA (ROA). BML were graded 0-3 (none, mild, moderate, severe) in 6 regions and defined as (1) BMLsum = the sum of 6 scores; and (2) BMLmax = the worst score at any region. Pain was assessed by the Western Ontario and McMaster Universities OA Index (WOMAC). Linear regression analysis was completed to assess the association of Total WOMAC Pain (primary outcome) versus BMLsum or BMLmax. Secondary outcomes were WOMAC Pain on Walking and WOMAC Pain on Climbing Stairs. All analyses were adjusted for age, sex, body mass index, OA stage, joint effusion, and meniscal damage. RESULTS: BML were present in 11% of NOA, 38% of PROA, and 71% of ROA subjects (p < 0.001). No association was seen for BMLsum or BMLmax versus Total WOMAC Pain or Pain on Walking. However, BMLsum was associated with Pain on Climbing Stairs [regression coefficients (RC) = 0.09, 95% CI 0.00-0.18]. BMLmax was associated with Pain on Climbing Stairs, with the strongest association for severe BML (RC 0.60, 95% CI 0.04-1.17). CONCLUSION: BML were present in 38% of PROA and 71% of ROA subjects in this symptomatic knee cohort. BML were significantly associated with Pain on Climbing Stairs but not Total WOMAC or Pain on Walking.

Association of clinical findings with pre-radiographic and radiographic knee osteoarthritis in a population-based study.

OBJECTIVE: To determine the prevalence of pre-radiographic osteoarthritis (ROA) and ROA of the knee in a symptomatic population-based cohort, and to evaluate the clinical correlates of pre-ROA and ROA. METHODS: Subjects ages 40-79 years with knee pain were recruited as a random population sample and classified using magnetic resonance cartilage (MRC) scores (range 0-4) and Kellgren/Lawrence (K/L) scale grades (range 0-4) as no OA (MRC score<2, K/L grade<2), pre-ROA (MRC score ≥2, K/L grade<2), and ROA (MRC score≥2, K/L grade≥2). Logistic regression was used to evaluate the association of clinical variables with cartilage defects, comparing subjects with any cartilage defects (pre-ROA/ROA) with those without, and to determine associations with individual OA subgroups. RESULTS: Of 255 symptomatic subjects, no OA, pre-ROA, and ROA were seen in 13%, 49%, and 38%, respectively. The prevalence of pre-ROA/ROA compared with no OA was associated with age (odds ratio [OR] 2.89, 95% confidence interval [95% CI] 1.59-5.26), sports activity (OR 1.35, 95% CI 1.07-1.70), abnormal gait (OR 10.86, 95% CI 1.46-1,388.4), effusion (OR 16.58, 95% CI 2.22-2,120.5), and flexion contracture (OR 2.37, 95% CI 1.50-3.73). The prevalence of ROA versus no OA was significantly associated with age, body mass index, pain frequency, pain duration, severe knee injury, sports activity, gait, effusion, bony swelling, crepitus, flexion contracture, and flexion. The prevalence of pre-ROA versus no OA was increased with age, sports activity, effusion, and flexion contracture, and reduced with valgus malalignment. CONCLUSION: Cartilage defects were highly prevalent in this symptomatic population-based cohort, with 49% of subjects having pre-ROA and 38% having ROA. Prevalent cartilage defects were significantly associated with age, sports activity, abnormal gait, effusion, and flexion contracture.

Dual-energy CT as a potential new diagnostic tool in the management of gout in the acute setting.

OBJECTIVE: Gout is the most common crystal deposition arthropathy currently diagnosed clinically and with arthrocentesis. Dual-energy CT is a promising new imaging technique offering potential new applications in a number of clinical areas. CONCLUSION: The ability of dual-energy CT to diagnose early gout and its use as a problem-solving tool is shown here. Diagnosis of subclinical gout could avert associated long-term complications, thereby reducing disease burden and improving overall quality of life.

Association of biomarkers with pre-radiographically defined and radiographically defined knee osteoarthritis in a population-based study.

OBJECTIVE: To evaluate 10 biomarkers in magnetic resonance imaging (MRI)-determined, pre-radiographically defined osteoarthritis (pre-ROA) and radiographically defined OA (ROA) in a population-based cohort of subjects with symptomatic knee pain. METHODS: Two hundred one white subjects with knee pain, ages 40-79 years, were classified into OA subgroups according to MRI-based cartilage (MRC) scores (range 0-4) and Kellgren/Lawrence (K/L) grades of radiographic severity (range 0-4): no OA (MRC score 0, K/L grade<2), pre-ROA (MRC score>or=1, K/L grade<2), or ROA (MRC score>or=1, K/L grade>or=2). Urine and serum samples were assessed for levels of the following biomarkers: urinary biomarkers C-telopeptide of type II collagen (uCTX-II), type II and types I and II collagen cleavage neoepitopes (uC2C and uC1,2C, respectively), and N-telopeptide of type I collagen, and serum biomarkers sC1,2C, sC2C, C-propeptide of type II procollagen (sCPII), chondroitin sulfate 846 epitope, cartilage oligomeric matrix protein, and hyaluronic acid. Multicategory logistic regression was performed to evaluate the association of OA subgroup with individual biomarker levels and biomarker ratios, adjusted for age, sex, and body mass index. RESULTS: The risk of ROA versus no OA increased with increasing levels of uCTX-II (odds ratio [OR] 3.12, 95% confidence interval [95% CI] 1.35-7.21), uC2C (OR 2.13, 95% CI 1.04-4.37), and uC1,2C (OR 2.07, 95% CI 1.06-4.04), and was reduced in association with high levels of sCPII (OR 0.53, 95% CI 0.30-0.94). The risk of pre-ROA versus no OA increased with increasing levels of uC2C (OR 2.06, 95% CI 1.05-4.01) and uC1,2C (OR 2.06, 95% CI 1.12-3.77). The ratios of type II collagen degradation markers to collagen synthesis markers were better than individual biomarkers at differentiating the OA subgroups, e.g., the ratio of [uCTX-II][uC1,2C] to sCPII was associated with a risk of ROA versus no OA of 3.47 (95% CI 1.34-9.03) and a risk of pre-ROA versus no OA of 2.56 (95% CI 1.03-6.40). CONCLUSION: Different cartilage degradation markers are associated with pre-ROA than are associated with ROA, indicating that their use as diagnostic markers depends on the stage of OA. Biomarker ratios contrasting cartilage degradation with cartilage synthesis are better able to differentiate OA stages compared with levels of the individual markers.

Real-time vessel segmentation and tracking for ultrasound imaging applications.

A method for vessel segmentation and tracking in ultrasound images using Kalman filters is presented. A modified Star-Kalman algorithm is used to determine vessel contours and ellipse parameters using an extended Kalman filter with an elliptical model. The parameters can be used to easily calculate the transverse vessel area which is of clinical use. A temporal Kalman filter is used for tracking the vessel center over several frames, using location measurements from a handheld sensorized ultrasound probe. The segmentation and tracking have been implemented in real-time and validated using simulated ultrasound data with known features and real data, for which expert segmentation was performed. Results indicate that mean errors between segmented contours and expert tracings are on the order of 1%-2% of the maximum feature dimension, and that the transverse cross-sectional vessel area as computed from estimated ellipse parameters a, b as determined by our algorithm is within 10% of that determined by experts. The location of the vessel center was tracked accurately for a range of speeds from 1.4 to 11.2 mm/s.

Utilization of ultrasound for the detection of pneumothorax in the neonatal special-care nursery.

Pneumothorax is a potentially life-threatening condition in the setting of the neonatal special-care nursery (SCN) that may result in rapid deterioration and death. The familiar appearances associated with pneumothorax on AP supine chest radiograph are highly specific, but limited in sensitivity. In this case report, we describe the theory and technique of thoracic ultrasound for detection of pneumothorax in the SCN, providing a viable alternative to the cross-table lateral radiograph without ionising radiation, with highly accurate results, and with minimal patient positioning.

Ollier's disease in association with adjacent fibromatosis.

Ollier's disease (enchondromatosis) is a nonhereditary disorder of mesodermal dysplasia. It is characterized by the presence of multiple enchondromas that typically affect the metaphyseal ends of bones. The association of Ollier's disease with adjacent fibromatosis has, to our knowledge, not been previously described. We report a case of Ollier's disease in association with soft tissue fibromatosis adjacent to the involved upper arm.