Self-Reported Health of Severely Obese US Adults With Osteoarthritis.

BACKGROUND: Severe obesity is associated with complications following arthroplasty, leading surgeons to increasingly counsel patients regarding weight loss. For patients seeking arthroplasty, learning that severe obesity may be a relative contraindication to surgery can create a challenging clinical interaction. We sought to describe the self-reported health of United States (US) adults who had severe obesity and osteoarthritis (OA) to better understand patient perspectives. METHODS: The National Health and Nutrition Examination Survey, a nationally representative sample of the US population, was used to identify adult participants who had a body mass index (BMI) over 35 and an OA diagnosis. In total, 889 participants representing a US population of 9,604,722 were included. Self-reported health was dichotomized as poor to fair versus good to excellent. Analyses were weighted to produce national estimates. Associations between obesity severity and patient characteristics with self-reported health were assessed. RESULTS: Of US adults with a BMI over 35 and OA diagnosis, 64% rated their health as good or better. For adults who had a BMI over 45, 55% still reported their health as good or better. The strongest predictors of self-reported health were measures of physical functioning. Only 37% of participants who had much difficulty walking a quarter mile rated their health as good or better compared to 86% without difficulty (P < .001). CONCLUSION: Approximately two-thirds of patients who have severe obesity and OA do not perceive their health as compromised and consider decreased physical function as the primary driver of decreased health. This suggests that counseling about the association between obesity and overall health may improve shared decision making and that patient satisfaction metrics may be difficult to interpret in these clinical situations.

An interactive videogame designed to improve respiratory navigator efficiency in children undergoing cardiovascular magnetic resonance.

BACKGROUND: Advanced cardiovascular magnetic resonance (CMR) acquisitions often require long scan durations that necessitate respiratory navigator gating. The tradeoff of navigator gating is reduced scan efficiency, particularly when the patient's breathing patterns are inconsistent, as is commonly seen in children. We hypothesized that engaging pediatric participants with a navigator-controlled videogame to help control breathing patterns would improve navigator efficiency and maintain image quality. METHODS: We developed custom software that processed the Siemens respiratory navigator image in real-time during CMR and represented diaphragm position using a cartoon avatar, which was projected to the participant in the scanner as visual feedback. The game incentivized children to breathe such that the avatar was positioned within the navigator acceptance window (±3 mm) throughout image acquisition. Using a 3T Siemens Tim Trio, 50 children (Age: 14 ± 3 years, 48 % female) with no significant past medical history underwent a respiratory navigator-gated 2D spiral cine displacement encoding with stimulated echoes (DENSE) CMR acquisition first with no feedback (NF) and then with the feedback game (FG). Thirty of the 50 children were randomized to undergo extensive off-scanner training with the FG using a MRI simulator, or no off-scanner training. Navigator efficiency, signal-to-noise ratio (SNR), and global left-ventricular strains were determined for each participant and compared. RESULTS: Using the FG improved average navigator efficiency from 33 ± 15 to 58 ± 13 % (p < 0.001) and improved SNR by 5 % (p = 0.01) compared to acquisitions with NF. There was no difference in navigator efficiency (p = 0.90) or SNR (p = 0.77) between untrained and trained participants for FG acquisitions. Circumferential and radial strains derived from FG acquisitions were slightly reduced compared to NF acquisitions (-16 ± 2 % vs -17 ± 2 %, p < 0.001; 40 ± 10 % vs 44 ± 11 %, p = 0.005, respectively). There were no differences in longitudinal strain (p = 0.38). CONCLUSIONS: Use of a respiratory navigator feedback game during navigator-gated CMR improved navigator efficiency in children from 33 to 58 %. This improved efficiency was associated with a 5 % increase in SNR for spiral cine DENSE. Extensive off-scanner training was not required to achieve the improvement in navigator efficiency.

2D cine DENSE with low encoding frequencies accurately quantifies cardiac mechanics with improved image characteristics.

BACKGROUND: Displacement Encoding with Stimulated Echoes (DENSE) encodes displacement into the phase of the magnetic resonance signal. The encoding frequency (ke) maps the measured phase to tissue displacement while the strength of the encoding gradients affects image quality. 2D cine DENSE studies have used a ke of 0.10 cycles/mm, which is high enough to remove an artifact-generating echo from k-space, provide high sensitivity to tissue displacements, and dephase the blood pool. However, through-plane dephasing can remove the unwanted echo and dephase the blood pool without relying on high ke. Additionally, the high sensitivity comes with the costs of increased phase wrapping and intra-voxel dephasing. We hypothesized that ke below 0.10 cycles/mm can be used to improve image characteristics and provide accurate measures of cardiac mechanics. METHODS: Spiral cine DENSE images were obtained for 10 healthy subjects and 10 patients with a history of heart disease on a 3 T Siemens Trio. A mid-ventricular short-axis image was acquired with different ke: 0.02, 0.04, 0.06, 0.08, and 0.10 cycles/mm. Peak twist, circumferential strain, and radial strain were compared between acquisitions employing different ke using Bland-Altman analyses and coefficients of variation. The percentage of wrapped pixels in the phase images at end-systole was calculated for each ke. The dephasing of the blood signal and signal to noise ratio (SNR) were also calculated and compared. RESULTS: Negligible differences were seen in strains and twist for all ke between 0.04 and 0.10 cycles/mm. These differences were of the same magnitude as inter-test differences. Specifically, the acquisitions with 0.04 cycles/mm accurately quantified cardiac mechanics and had zero phase wrapping. Compared to 0.10 cycles/mm, the acquisitions with 0.04 cycles/mm had 9 % greater SNR and negligible differences in blood pool dephasing. CONCLUSIONS: For 2D cine DENSE with through-plane dephasing, the encoding frequency can be lowered to 0.04 cycles/mm without compromising the quantification of twist or strain. The amount of wrapping can be reduced with this lower value to greatly simplify the input to unwrapping algorithms. The strain and twist results from studies using different encoding frequencies can be directly compared.

Validation of in vivo 2D displacements from spiral cine DENSE at 3T.

BACKGROUND: Displacement Encoding with Stimulated Echoes (DENSE) encodes displacement into the phase of the magnetic resonance signal. Due to the stimulated echo, the signal is inherently low and fades through the cardiac cycle. To compensate, a spiral acquisition has been used at 1.5T. This spiral sequence has not been validated at 3T, where the increased signal would be valuable, but field inhomogeneities may result in measurement errors. We hypothesized that spiral cine DENSE is valid at 3T and tested this hypothesis by measuring displacement errors at both 1.5T and 3T in vivo. METHODS: Two-dimensional spiral cine DENSE and tagged imaging of the left ventricle were performed on ten healthy subjects at 3T and six healthy subjects at 1.5T. Intersection points were identified on tagged images near end-systole. Displacements from the DENSE images were used to project those points back to their origins. The deviation from a perfect grid was used as a measure of accuracy and quantified as root-mean-squared error. This measure was compared between 3T and 1.5T with the Wilcoxon rank sum test. Inter-observer variability of strains and torsion quantified by DENSE and agreement between DENSE and harmonic phase (HARP) were assessed by Bland-Altman analyses. The signal to noise ratio (SNR) at each cardiac phase was compared between 3T and 1.5T with the Wilcoxon rank sum test. RESULTS: The displacement accuracy of spiral cine DENSE was not different between 3T and 1.5T (1.2 ± 0.3 mm and 1.2 ± 0.4 mm, respectively). Both values were lower than the DENSE pixel spacing of 2.8 mm. There were no substantial differences in inter-observer variability of DENSE or agreement of DENSE and HARP between 3T and 1.5T. Relative to 1.5T, the SNR at 3T was greater by a factor of 1.4 ± 0.3. CONCLUSIONS: The spiral cine DENSE acquisition that has been used at 1.5T to measure cardiac displacements can be applied at 3T with equivalent accuracy. The inter-observer variability and agreement of DENSE-derived peak strains and torsion with HARP is also comparable at both field strengths. Future studies with spiral cine DENSE may take advantage of the additional SNR at 3T.

Spine patients demystified: what are the predictive factors of poor surgical outcome in patients after elective cervical and lumbar spine surgery?

BACKGROUND CONTEXT: Pre-existing comorbid psychiatric mood disorders are a known risk factor for impaired health-related quality of life and poor long-term outcomes after spine surgery. PURPOSE: The purpose of this study was to investigate the effect of preexisting mood disorders on (1) pre- and postoperative patient-reported outcomes, (2) complications, and (3) pre- and postoperative opioid consumption in patients undergoing elective cervical or lumbar spine surgery. STUDY DESIGN/SETTING: Retrospective review at a single academic institution from 2014 to 2017. PATIENT SAMPLE: Consecutive adult patients who underwent cervical or lumbar surgery. OUTCOME MEASURES: Quantitative measurements of pain (visual analog scale [VAS]) and spinal region-specific disability scores (Neck Disability Index [NDI] and Oswestry Disability Index [ODI]). METHODS: This is a retrospective review of 435 consecutive patients (179 cervical, 256 lumbar) who underwent elective spine surgery at a single academic institution from 2014 to 2017. Patient preoperative diagnosis of psychiatric mood disorder (eg, depression, anxiety, schizophrenia, bipolar, or dementia), baseline characteristics, medical (nonpsychiatric) comorbidities, operative variables, and surgical complications (eg, superficial and deep infection, wound complication, emergency department [ED] visits, readmissions, and repeat operations) were recorded. Additionally, preoperative ED visits, pre- and postoperative opioid requirements, total opioid prescription quantities and most recent dateof opioid prescription were collected. VAS, NDI, and ODI scores were recorded preoperatively and at 2, 6, and 12 weeks after surgery. Continuous variables were compared between those with and without diagnosed psychiatric comorbidity using two-tailed independent t test, and categorical variables were compared using chi-square or Fisher's exact tests. Analyses of variance and analysis of covariance were used to compare patient-reported outcomes between groups. A multivariate approach was taken to account for contribution of potential covariates in significant findings. Multiple linear regressions were used to determine variables associated with the number of postoperative opioid prescriptions. RESULTS: Of the cervical and lumbar cohorts, 78 (43.6%) and 113 (44.1%), respectively, had a preoperative diagnosis of comorbid psychiatric mood disorder. Cervical patients with mood disorders received a significantly higher total number of opioid prescriptions post-operatively (4.6±5.2 vs. 2.8±3.9; p=.002). Patients with mood disorders had worse NDI scores at all time points (p=.04), however there were no differences in VAS pain scores (p=.5). There were no statistical differences between patients with and without mood disorders regarding baseline characteristics, medical (nonpsychiatric) comorbidities, operative variables, surgical complications, preoperative ED visits or prior opioid use (p>.05). For lumbar patients, patients with mood disorders were more commonly females (p=.04), tobacco users (p=.003), alcohol dependent (p=.01) and illicit-drug abusers (p=.03). There were no differences regarding surgical complications or opioid consumption. Tobacco use (p<.001) was the sole contributor to postoperative VAS pain scores. Patients with mood disorders had significantly higher VAS values both before and 3 months following surgery (p=.01), but there was no difference in ODI scores. CONCLUSIONS: Patients with preoperative psychiatric mood disorders undergoing elective cervical surgery had worse NDI scores and received more opioid prescriptions, despite similar VAS scores as those without mood disorders. Lumbar surgery patients with mood disorders were demographically different than those without mood disorders and had worse pain before and after surgery, though ODI scores were not different. Tobacco use was the sole contributor to postoperative VAS pain scores. This information can be useful in counseling patients with mood disorders before elective spinal surgery.

Right Ventricular Strain, Torsion, and Dyssynchrony in Healthy Subjects Using 3D Spiral Cine DENSE Magnetic Resonance Imaging.

Mechanics of the left ventricle (LV) are important indicators of cardiac function. The role of right ventricular (RV) mechanics is largely unknown due to the technical limitations of imaging its thin wall and complex geometry and motion. By combining 3D Displacement Encoding with Stimulated Echoes (DENSE) with a post-processing pipeline that includes a local coordinate system, it is possible to quantify RV strain, torsion, and synchrony. In this study, we sought to characterize RV mechanics in 50 healthy individuals and compare these values to their LV counterparts. For each cardiac frame, 3D displacements were fit to continuous and differentiable radial basis functions, allowing for the computation of the 3D Cartesian Lagrangian strain tensor at any myocardial point. The geometry of the RV was extracted via a surface fit to manually delineated endocardial contours. Throughout the RV, a local coordinate system was used to transform from a Cartesian strain tensor to a polar strain tensor. It was then possible to compute peak RV torsion as well as peak longitudinal and circumferential strain. A comparable analysis was performed for the LV. Dyssynchrony was computed from the standard deviation of regional activation times. Global circumferential strain was comparable between the RV and LV (-18.0% for both) while longitudinal strain was greater in the RV (-18.1% vs. -15.7%). RV torsion was comparable to LV torsion (6.2 vs. 7.1 degrees, respectively). Regional activation times indicated that the RV contracted later but more synchronously than the LV. 3D spiral cine DENSE combined with a post-processing pipeline that includes a local coordinate system can resolve both the complex geometry and 3D motion of the RV.