The Subjective Hip Value is a Valid, Reliable, and Responsive Instrument for Assessing Hip Function in Primary Total Hip Arthroplasty.

BACKGROUND: Patient-reported outcome measures are essential tools in clinical decision-making and research. Multi-item scores like the modified Harris Hip Score (mHHS) are time-consuming to collect and evaluate. The subjective hip value (SHV), as a single-item value, assesses hip function with one question: "What is the overall percent value of your hip if a completely normal hip represents 100%?". The aims of our study were to assess the psychometric properties, and thus validity, reliability, and responsiveness; and to define the minimal clinically important difference (MCID) of the SHV in patients undergoing total hip arthroplasty. METHODS: A total of 137 consecutive patients who underwent primary total hip arthroplasty between June 2020 and August 2021 were prospectively enrolled. A SHV and mHHS were collected preoperatively and at follow-ups (6 weeks, 3 months, 6 months, and 1 year). Validity, reliability, responsiveness, MCID, and floor/ceiling effects were evaluated. RESULTS: There was a significant correlation between SHV and mHHS (P = .001) preoperatively (rs = 0.532), 6 weeks (rs = 0.649), 3 months (rs = 0.765), 6 months (rs = 0.854), and after 1 year (rs = 0.879). Test-retest reliability (rs = 0.74; P = .001) and responsiveness (rs = 0.24; P = .007) showed significant correlations. The MCID for SHV was 10.06%. Floor- and ceiling-effects were comparable to the mHHS. CONCLUSIONS: The SHV is a valid, reliable, and responsive single-item score for the assessment of hip joint function in arthroplasty patients. It can detect clinically relevant changes in joint function and is easy to collect and interpret, which justifies its implementation in clinical practice.

Insights into the Versatility of Using Atomic Absorption Spectrometry in Antibacterial Research.

The ongoing development of bacterial resistance to antibiotics is a global challenge. Research in that field is thus necessary. Analytical techniques are required for such a purpose. From this perspective, the focus was on atomic absorption spectrometry (AAS). Although it is old, AAS often offers unexpected potential. Of course, this should be exploited. The aim was therefore to demonstrate the versatility of the technique in antibacterial research. This is illustrated by various examples of its practical application. AAS can be used, for example, to confirm the identity of antibacterial compounds, for purity controls, or to quantify the antibiotics in pharmaceutical preparations. The latter allowed analysis without laborious sample preparation and without interference from other excipients. In addition, AAS can help elucidate the mode of action or resistance mechanisms. In this context, quantifying the accumulation of the antibiotic drug in the cell of (resistant) bacteria appears to play an important role. The general application of AAS is not limited to metal-containing drugs, but also enables the determination of some organic chemical antibiotics. Altogether, this perspective presents a range of applications for AAS in antibacterial research, intending to raise awareness of the method and may thus contribute to the fight against resistance.

Development and Application of an Atomic Absorption Spectrometry-Based Method to Quantify Magnesium in Leaves of Dioscorea polystachya.

The Chinese yam (Dioscorea polystachya, DP) is known for the nutritional value of its tuber. Nevertheless, DP also has promising pharmacological properties. Compared with the tuber, the leaves of DP are still very little studied. However, it may be possible to draw conclusions about the plant quality based on the coloration of the leaves. Magnesium, as a component of chlorophyll, seems to play a role. Therefore, the aim of this research work was to develop an atomic absorption spectrometry-based method for the analysis of magnesium (285.2125 nm) in leaf extracts of DP following the graphite furnace sub-technique. The optimization of the pyrolysis and atomization temperatures resulted in 1500 °C and 1800 °C, respectively. The general presence of flavonoids in the extracts was detected and could explain the high pyrolysis temperature due to the potential complexation of magnesium. The elaborated method had linearity in a range of 1-10 µg L-1 (R2 = 0.9975). The limits of detection and quantification amounted to 0.23 µg L-1 and 2.00 µg L-1, respectively. The characteristic mass was 0.027 pg, and the recovery was 96.7-102.0%. Finally, the method was applied to extracts prepared from differently colored leaves of DP. Similar magnesium contents were obtained for extracts made of dried and fresh leaves. It is often assumed that the yellowing of the leaves is associated with reduced magnesium content. However, the results indicated that yellow leaves are not due to lower magnesium levels. This stimulates the future analysis of DP leaves considering other essential minerals such as molybdenum or manganese.

Interacting Chern Insulator in Infinite Spatial Dimensions.

We study a generic model of a Chern insulator supplemented by a Hubbard interaction in arbitrary even dimension D and demonstrate that the model remains well defined and nontrivial in the D→∞ limit. Dynamical mean-field theory is applicable and predicts a phase diagram with a continuum of topologically different phases separating a correlated Mott insulator from the trivial band insulator. We discuss various features, such as the elusive distinction between insulating and semimetal states, which are unconventional already in the noninteracting case. Topological phases are characterized by a nonquantized Chern density replacing the Chern number as D→∞.

Leveraging Interactive Patient Care Technology to Improve Pain Management Engagement.

BACKGROUND: Most children experience pain in hospitals; and their parents report dissatisfaction with how well pain was managed. Engaging patients and families in the development and evaluation of pain treatment plans may improve perceptions of pain management and hospital experiences. OBJECTIVES: The aim of this performance improvement project was to engage patients and families to address hospitalized pediatric patients' pain using interactive patient care technology. The goal was to stimulate conversations about pain management expectations and perceptions of treatment plan effectiveness among patients, parents, and health care teams. METHODS: Plan-Do-Study-Act was used to design, develop, test, and pilot new workflows to integrate the interactive patient care technology system with the automated medication dispensing system and document actions from both systems into the electronic health record. SETTING: The pediatric surgical unit and hematology/oncology unit of a free-standing, university-affiliated, urban children's hospital were selected to pilot this performance improvement project because of the high prevalence of pain from surgeries and hematologic and oncologic diseases, treatments, and invasive procedures. RESULTS: Documentation of pain assessments, nonpharmacologic interventions, and evaluation of treatment effectiveness increased. The proportion of positive family satisfaction responses for pain management significantly increased from fiscal year 2014 to fiscal year 2016 (p = .006). CONCLUSION: By leveraging interactive patient care technologies, patients and families were engaged to take an active role in pain treatment plans and evaluation of treatment outcomes. Improved active communication and partnership with patients and families can effectively change organizational culture to be more sensitive to patients' pain and patients' and families' hospital experiences.

Arthroscopic treatment of femoroacetabular impingement shows persistent clinical improvement in the mid-term.

INTRODUCTION: The concept of femoroacetabular impingement (FAI) and the indication for surgical intervention have been established in the last decade. Despite promising short-term results and emerging arthroscopic techniques, it remains unclear whether patients benefit from surgical correction in the mid- to long-term and whether progressive joint degeneration can be prevented. MATERIALS AND METHODS: A retrospective study of our first 50 consecutive patients who underwent arthroscopic correction for FAI was conducted. The modified Harris hip score (mHHS) was assessed preoperatively and at final follow-up. In addition, the Western Ontario and McMaster Universities osteoarthritis index (WOMAC) and a subjective hip value (SHV) were added at final follow-up. Degenerative changes according to Kellgren and Lawrence scale and the α angle were analyzed preoperatively and on the most recent radiograph. RESULTS: Of a total of 50 patients, 44 (24 male, 20 female) with a mean age of 34.3 years (17-65) were available with complete follow-up. Of these 44 patients, 39 were treated with correction of the femoral offset for isolated cam deformity, 5 with additional focal pincer correction and partial labral resection. After a mean follow-up of 66.3 ± 14.5 months the mHHS had improved significantly from 67.2 ± 6.4 preoperatively to 86.4 ± 13.5 (p < 0.001). The WOMAC score (converted to 0 = best/100 = worst) resulted in mean indices for the subcategories pain, stiffness and function of 11.8 ± 16.5, 12.2 ± 17.8 and 9.1 ± 16.1. The SHV was reported with a mean of 77.7 ± 21.8 % at final follow-up. The α angle was reduced significantly from 57.2° ± 10.1° to 46.3° ± 7.4° (p < 0.001). The Kellgren and Lawrence score showed a non-significant trend from 2.0 ± 0.8 preoperatively to 2.2 ± 0.9 in the most recent radiograph (p = 0.46). 5 patients had been converted to a total hip arthroplasty a mean of 28 ± 7.1 months postoperatively. These patients were significantly (p < 0.01) older with a mean age of 49.8 ± 7.8 years and showed significantly higher present osteoarthritic changes with an average Kellgren and Lawrence score of 2.6 ± 2.5 before FAI correction (p < 0.01). CONCLUSIONS: Arthroscopic correction of femoroacetabular impingement results in a persistent clinical improvement without significant progression of degenerative changes in the majority of patients. The indication for surgery should be established cautiously when degenerative changes are present. LEVEL OF EVIDENCE: Level IV, Case series with no comparison group.

Histopathologic evaluation of passive stabilizers in shoulder instability.

BACKGROUND: The macroscopic pathomorphology in recurrent shoulder instability has been described. However, less is known regarding the histopathologic details of the affected structures. This study evaluates different histopathologic stages of shoulder instability by assessing biopsy specimens of static stabilizers for possible correlations with clinical parameters. Our hypothesis was that clinical parameters of shoulder instability correlate with histopathologic findings. MATERIALS AND METHODS: Passive shoulder stabilizers (labrum, anterior bundle of the inferior glenohumeral ligament) were biopsied during arthroscopic shoulder stabilization. Samples were submitted to immunohistochemistry, in situ hybridization, and blinded evaluation. Clinical data, comprising age (<30 years or ≥30 years), total number of dislocations (1, 2-3, or >3), and period since initial dislocation (<6 months, 6 months to 6 years, or >6 years), were tested for statistical correlation with the following histopathologic parameters: inflammation, lipomatous changes, vascular proliferation, tissue fragmentation, and cellularity. RESULTS: Standardized biopsies were performed in 30 consecutive patients (4 women and 26 men; mean age, 32.6 years) with anterior shoulder instability. Microscopic evaluation showed only small variations in histologic changes among all samples. Only limited variations in cell density, matrix swelling, and collagen fiber disruptions were found. Immunohistochemical analysis showed a similar expression of decorin in all samples. Clinical parameters (age, total number of dislocations, and period since initial dislocation) were statistically independent from histopathologic parameters (inflammation, lipomatous changes, vascular proliferation, tissue fragmentation, and cellularity). No correlation was found in patients with 1 dislocation versus those with more than 1 dislocation. CONCLUSIONS: In contrast to macroscopic findings among different grades of shoulder instability, this study detected no correlation between clinical items (age, total number of dislocations, and period since initial dislocation) and histopathologic parameters. These clinical items seem to be independent from the tissue status of static stabilizers of the shoulder.

Hip Abductor Deficiency after Total Hip Arthroplasty: Diagnostic and Therapeutic Methods. / Glutealinsuffizienz nach Hüfttotalendoprothese: Diagnostik und Therapieverfahren.

Abductor deficiency after total hip arthroplasty is a severe complication with functional limitations and a significant reduction in the patient's quality of life. Common causes are degenerative ruptures or approach-related iatrogenic damage to the gluteus medius and minimus muscle and the inferior gluteal nerve, fractures of the greater trochanter and incorrect reconstruction of leg length and femoroacetabular offset. With a standardised diagnosis consisting of a clinical examination, conventional X-ray and MRI, the causes of the functional problems can often be reliably determined. Therapy of abductor deficiency is challenging for both patients and physicians and is often tedious. However, with a clear diagnostic and therapeutic algorithm and straightforward patient education, good treatment results can be achieved even in this challenging condition. Conservative therapy with eccentric stretching and muscle strengthening are the basis of the treatment. In cases of progression of complaints despite intensive conservative treatment, various anatomical and extra-anatomical surgical reconstruction methods are available to relieve pain and improve function. Anatomical reconstruction of the gluteal tendon insertion is an option in cases of low-grade fatty infiltration and moderate retraction of the gluteal muscles. In situations with advanced degenerative changes in the gluteus medius and minimus muscles and an intact gluteus maximus muscle, transfer of the anterior portion of the gluteus maximus according to Whiteside is an option. For high-grade defects of the soft tissue, there is also the option of an isolated or combined transfer of the vastus lateralis muscle.

Effect of total hip arthroplasty on brake reaction time and braking force.

INTRODUCTION: The correct moment for return to driving after total hip arthroplasty (THA) remains unclear. Until today no uniform recommendation exists on the ability to perform an emergency brake.The aim of this prospective study was to investigate the braking ability of patients before and after THA implantation based on brake reaction time in milliseconds (BRT) and braking force in N (BF). METHODS: In total, 25 patients (15 men, 10 women, mean age 51.3 ± 10.1 years) were treated with THA on the right side. Inclusion criteria consisted of a valid driving licence, frequent road participation and at least 2 years of driving experience. Exclusion criteria were underlying neurological disorders as well as severe complaints in the lumbar spine and the right knee joint. The brake ability was evaluated for emergency braking with a car simulator and a measuring sole. Measurements were performed preoperatively, 6 days, 2, 4 and 6 weeks after surgery. RESULTS: Preoperatively, the mean BRT was 671.3 ± 123.5 ms and the BF 455.4 ± 185.0 N. Significant differences were observed at 6 days and 2 weeks after surgery, (BRT 836.4 ± 219.7 ms, respectively, BRT 735.0 ± 186.7 ms, and BF 302.6 ± 154.9 N, respectively, BF 375.5 ± 149.3 N, p < 0.05). Only 4 weeks after, no significant differences were seen compared to pre-operative with a BRT of 647.0 ± 91.9ms (p = 0.354) and BF of 435.9 ± 177.4 (p = 0.843). Furthermore, the BRT improved significantly after 6 weeks (607.4 ± 87.6; p = 0.005). CONCLUSIONS: The braking force is significantly reduced, and the brake reaction time is prolonged directly after surgery for at least 2 weeks. After 4 weeks, no statistically significant differences were measured, although special care should still be taken during return to activity.

Metal on Metal Bearing in Total Hip Arthroplasty and Its Impact on Synovial Cell Count.

INTRODUCTION: The effect of different bearings on synovial white blood cell (WBC) count and polymorphonuclear percentage (PMN%) in aspirations remains unclear. Therefore, this study investigates the impact of aseptic Metal-on-Metal (MoM) bearing on synovial fluid. METHODS: We searched our arthroplasty registry for aseptic painful THAs with MoM bearings between 2011 and 2018. Then, a case-matched control group was selected with septic and aseptic Total Hip Arthroplasty (THA) with ceramic on a polyethylene (PE) bearing. The matching criteria consisted of gender, age +/-10 years, and time of aspiration (+/-2years). Periprosthetic Joint Infection (PJI) was defined according to the Infectious Diseases Society of America (IDSA), and Musculoskeletal Infection Society (MSIS) using bacterial cultures, sonication and histology. RESULTS: In total, 19 patients who underwent hip aspiration with MoM bearing were identified. Five patients had to be excluded due to insufficient synovial fluid obtained (n = 2) or bacterial growth after sonication that was initially negative with the standard microbiological cultures (n = 3). As such, 14 were included. These patients were matched with 14 aseptic and 14 septic THAs with ceramic on a PE bearing, which constituted the control group. The mean serum chrome level was 20.0 ± 15.5 nmol/L and cobalt level 18.4 ± 22.1 nmol/L. The synovial WBC and PMN% varied significantly between MoM bearing group and the aseptic THA ceramic PE group (both p < 0.001), as well as the septic THA group (WBC p = 0.016, PMN% p < 0.001). Furthermore, the septic THA group had significantly higher CRP values than the aseptic MoM group (p = 0.016). CONCLUSION: MoM bearing shows significantly higher synovial WBC and PMN% when compared to aseptic THA with ceramic on PE bearing above the MSIS cut-off. This is an important consideration when diagnosing periprosthetic joint infection using the MSIS guidelines.

Arthroscopic Reconstruction of Multifragmented Anteroinferior Glenoid Rim Fractures.

BACKGROUND: The optimal treatment of anteroinferior glenoid rim fractures remains a matter of debate. Surgical repair aims to prevent persistent instability and osteoarthritic changes of the glenohumeral joint1-3 and is recommended in patients with a subluxated humeral head and substantial displacement of the fracture fragment(s)3-5. Arthroscopic reconstruction with suture anchors was described by Sugaya et al. for large solitary glenoid rim fractures using an indirect reduction and fixation via labral repair6. We present the arthroscopic reconstruction of a multifragmented anteroinferior glenoid rim fracture using a modified knotless anchor technique and bioabsorbable pins. The additional fixation and compression may improve reduction and consolidation of the fracture. DESCRIPTION: The patient is placed in the lateral decubitus position with the affected arm fixed in a traction device. A standard posterior, an anterosuperior (suprabicipital), and a deep anteroinferior portal are required for this minimally invasive technique. A posterolateral portal may be required additionally. First, a diagnostic arthroscopy is performed to identify possible concomitant lesions. Labral repair enables an indirect reduction of the attached fracture fragments and is achieved by the aid of knotless suture anchors. Temporary reduction using Kirschner wires can be applied. Bioabsorbable pins can be used for additional ultimate fixation and compression of the fracture fragments. ALTERNATIVES: A variety of surgical techniques for the reconstruction of glenoid rim fractures have been described in the literature, including open or arthroscopic screw osteosynthesis using either metallic or bioabsorbable screws3,6-10. Screw osteosynthesis, however, is not a feasible option for fractures with multiple small fragments3. Isolated suture anchor reconstruction represents another alternative6. Good clinical results and a high subjective satisfaction rate, however, can also be achieved by nonoperative treatment, depending on the patient and fracture characteristics3,10-12. RATIONALE: This minimally invasive technique enables an almost anatomical reconstruction of the glenoid rim with a minor risk of hardware impingement compared with screw osteosynthesis.

Multi-Parameter Analysis of Biobanked Human Bone Marrow Stromal Cells Shows Little Influence for Donor Age and Mild Comorbidities on Phenotypic and Functional Properties.

Heterogeneous populations of human bone marrow-derived stromal cells (BMSC) are among the most frequently tested cellular therapeutics for treating degenerative and immune disorders, which occur predominantly in the aging population. Currently, it is unclear whether advanced donor age and commonly associated comorbidities affect the properties of ex vivo-expanded BMSCs. Thus, we stratified cells from adult and elderly donors from our biobank (n = 10 and n = 13, mean age 38 and 72 years, respectively) and compared their phenotypic and functional performance, using multiple assays typically employed as minimal criteria for defining multipotent mesenchymal stromal cells (MSCs). We found that BMSCs from both cohorts meet the standard criteria for MSC, exhibiting similar morphology, growth kinetics, gene expression profiles, and pro-angiogenic and immunosuppressive potential and the capacity to differentiate toward adipogenic, chondrogenic, and osteogenic lineages. We found no substantial differences between cells from the adult and elderly cohorts. As positive controls, we studied the impact of in vitro aging and inflammatory cytokine stimulation. Both conditions clearly affected the cellular properties, independent of donor age. We conclude that in vitro aging rather than in vivo donor aging influences BMSC characteristics.

[Radiologic Presentation in Subspine Impingement and Correlation with Intraarticular Impingement in the Hip]. / Konventionell-radiologische Darstellung des subspinalen Impingements und Koinzidenz mit intraartikulärem Impingement am Hüftgelenk.

Background Besides the known intraarticular femoroacetabular impingement (FAI), recently forms of extra-articular impingement of the hip have been increasingly recognized. Recent studies have described an extra-articular impingement between a distal extension of the anterior inferior iliac spine (AIIS) and the femoral neck (AIIS or subspine impingement). Evidently, an association between this subspine impingement and an intraarticular FAI seems to exist. Little is known about the incidence of this impingement type and the value of its radiological diagnostics. The aim of this study was therefore to evaluate the correlation of a subspine impingement with intraarticular femoroacetabular impingement and radiological criteria of subspine impingement. Material and Methods In 2013 arthroscopic correction of intra-articular femoroacetabular impingement was performed in 80 cases. This collective was evaluated for simultaneous intraoperative findings of subspine impingement. In addition, the patients were evaluated for radiological signs of subspine impingement in conventional X-ray. A projection of the AIIS either below the acetabular sourcil or the anterior acetabular rim in an AP pelvis X-ray was considered as a radiological sign of low AIIS formation. These radiological findings were compared with the presence of intraoperative signs for subspine impingement, which are defined as a combination of focal capsule synovitis, labral ecchymosis close to the AIIS and a decreased offset between the acetabular rim and the AIIS. The specificity and sensitivity of the pre-operative radiological signs were calculated. Results A subspine impingement was found in 17 cases (21 %, 3 female, 14 male, mean age 28 years). A projection of the AIIS caudal to the acetabular sourcil in the AP pelvis X-ray was represented in 15 of the 17 cases detected (sensitivity 0.90, specificity 0.88). A projection below the anterior glenoid rim was detectable in 2 cases with symptomatic AIIS impingement (sensitivity 0.12, specificity 1). Conclusion A relevant proportion of patients with intraarticular FAI showed intraoperative signs for an additive extraarticular AIIS impingement. Preoperative pelvic X-rays are helpful with a sensitivity of 90 % in detecting the presence of a distal extension of the AIIS in FAI patients. Evaluation of the preoperative AP pelvis x-ray should include the projection of the AIIS. We recommend evaluation for subspine impingement during routine arthroscopy.

Arthroscopic Treatment for Primary Septic Arthritis of the Hip in Adults.

Purpose. Primary septic arthritis is a rare differential diagnosis of acute hip pain in adults. Inspired by the success of all-arthroscopic treatment in pediatric patients, we developed a diagnostic and surgical pathway for our adult patients. Methods. Seven patients, average age 44 ± 13.7 years with acute hip pain since 4.4 ± 2.9 days in the average, were included. Septic arthritis was confirmed by joint aspiration and dissemination was excluded by MRI and standard radiographs. Surgical treatment consisted of immediate arthroscopic lavage using 4 portals for debridement, high-volume irrigation, partial synovectomy, and drainage. Results. Patients were treated in hospital for 12.4 ± 3.1 days (range 7-16 days). WBC and CRP returned to physiological levels. During the mean follow-up of 26.4 ± 19.4 months (range 13-66 months) no patient showed recurrence of infection. The 5 patients with an unimpaired hip joint prior to the infection had a mean modified Harris Hip Score of 94 ± 5.6 points (range 91-100) at final follow-up. Conclusions. Arthroscopic therapy using a minimally invasive approach with low perioperative morbidity for the treatment of primary septic arthritis of the adult hip is able to restore normal hip function in acute cases without dissemination of the infection. Level of Evidence. IV.

Progenitor cell therapy in a porcine acute myocardial infarction model induces cardiac hypertrophy, mediated by paracrine secretion of cardiotrophic factors including TGFbeta1.

Administration of endothelial progenitor cells (EPC) is a promising therapy for post-infarction cardiac repair. However, the mechanisms that underlie apparent beneficial effects on myocardial remodeling are unclear. In a porcine model of acute myocardial infarction, we investigated the therapeutic effects of a mixed population of culture modified peripheral blood mononuclear cells (termed hereafter porcine EPC). Porcine EPC were isolated using methods identical to those previously adopted for harvest of EPC in human cell therapy studies. In addition the therapeutic effects of paracrine factors secreted by these cells was evaluated in vitro and in vivo. Intracoronary injection of autologous porcine EPC was associated with increased infarct territory mass and improved regional ventricular systolic function at 2 months compared to control. Treatment with conditioned media derived from autologous EPC was associated with similar improved effects on infarct territory mass and function. Histologic analysis of the infarct territory revealed significantly increased cardiomyocyte size in EPC and conditioned media treated groups, when compared to controls. A paracrine EPC effect was also verified in a pure myocardial preparation in which cardiomyocytes devoid of fibroblast, neuronal and vascular elements directly responded by increasing cell mass when exposed to the same conditioned media. Analysis of conditioned media revealed elevated levels of TGFbeta1 (human 267.3+/-11.8 pg/ml, porcine 57.1+/-6.1 pg/ml), a recognized mediator of hypertrophic signaling in the heart. Neutralizing antibodies to TGFbeta1 attenuated the pro-hypertrophic effect of conditioned media, and use of recombinant TGFbeta1 added to fresh media replicated the pro-hypertrophic effects of conditioned media in vitro. These data demonstrate the potential of paracrine factors secreted from endothelial progenitor cells to induce cardiomyocyte hypertrophy contributing to increased infarct territory LV mass, with favorable medium term effects on regional function following myocardial infarction.

High-spatial-resolution contrast-enhanced MR angiography of the intracranial venous system with fourfold accelerated two-dimensional sensitivity encoding.

Informed consent was obtained; the study was HIPAA compliant and institutional review board approved. Fourfold accelerated (FFA) two-dimensional (2D) sensitivity encoding (SENSE) (65 seconds) was prospectively compared with its nonaccelerated counterpart (4 minutes 20 seconds) for diagnostic image quality and sharpness of visualization of blood vessels at 1.5 T with three-dimensional (3D) intracranial contrast-enhanced magnetic resonance venography in 18 consecutive volunteers (10 men, eight women; mean age, 48.4 years) and two patients (55-year-old man, 30-year-old woman). Two readers compared FFA 2D SENSE results with results from its nonaccelerated counterpart; they rated visualization of large and medium sinuses as equivalent (P>.1) and that of small deep cerebral veins (P<.01) and superficial cerebral veins (P<.001) as superior. Overall diagnostic image quality ratings were excellent for 62% and 80% of nonaccelerated and FFA 2D SENSE results, respectively (P<.05). FFA 2D SENSE may become the method of choice for fast visualization of intracranial venous vasculature in clinical practice.

Intrinsic signal amplification in the application of 2D SENSE parallel imaging to 3D contrast-enhanced elliptical centric MRA and MRV.

The relative signal-to-noise ratio (SNR) provided by 2D sensitivity encoding (SENSE) when applied to 3D contrast-enhanced MR angiography (CE-MRA) is studied. If an elliptical centric phase-encoding order is used to map the waning magnetization of the contrast bolus to k-space, the application of SENSE will reduce the degree of k-space signal modulation, providing a signal amplification A over corresponding nonaccelerated acquisitions. This offsets the SNR loss in R-accelerated SENSE due to suquare root R and the geometry (g) factor. The theoretical bound on A is R and is reduced from this depending on the properties of the bolus profile and the duration over which it is imaged. In this work a signal amplification of 1.14-1.23 times that of nonvascular background tissue is demonstrated in a study of 20 volunteers using R = 4 2D SENSE whole-brain MR venography (MRV). The effects of a nonuniform g-factor and inhomogeneity of background tissue are accounted for. The observed amplification compares favorably with the value of 1.31 predicted numerically from a measured bolus curve.

Cardiotropin-1 and myocardial strain change heterogeneously in cardiomyopathy.

BACKGROUND: The pacing model of heart failure produces heterogeneous changes in wall stress and myocyte diameter. The purpose of this study was to measure regional changes in cardiotrophin-1 (CT-1), a cytokine thought to play a role in LV remodeling, and regional changes in LV strain as measured with magnetic resonance imaging. MATERIALS AND METHODS: Dilated cardiomyopathy was induced in nine mongrel dogs over 4 wk by rapid pacing using a right ventricular epicardial lead. Baseline CT-1 was measured from an apical myocardial biopsy, and regional CT-1 was measured from anterior, lateral, inferior, and septal walls after the induction of heart failure and in six control dogs. Tissue tagged images were divided into similar regions and minimal principal strain (MPS), ejection fraction, and ventricular volumes were compared after induction of heart failure. RESULTS: After induction of heart failure, LV ejection fraction and end-diastolic volume differed significantly from baseline (P < 0.01 and P = 0.02, respectively). Additionally, regional CT-1 and MPS were significantly different (P < 0.01 for both). Cardiotrophin-1 increased significantly in the inferior and septal walls (both P < 0.01) but not in the anterior or lateral walls (both P = NS). Minimum principal strain decreased significantly in the inferior and septal walls (both P < 0.01) but not in the anterior or lateral walls (both P = NS). CONCLUSION: The pacing model of heart failure produces heterogeneous changes in regional CT-1 and wall motion as measured by MPS. The greatest regional changes are closest to the pacemaker site: the inferior and septal walls. These differences in regional CT-1 may account for previously noted myocyte hypertrophy and preserved ventricular function in these regions.

Combination of 2D sensitivity encoding and 2D partial fourier techniques for improved acceleration in 3D contrast-enhanced MR angiography.

Sensitivity encoding (SENSE) and partial Fourier (PF) techniques both reduce MRI acquisition time. Two-dimensional SENSE uses coil sensitivities to unfold aliasing in the phase/slice-encoding plane. One-dimensional PF and homodyne reconstruction are routinely applied in the frequency/phase-encoding plane to compensate for nonsampled k-space of the presumed real magnetization. Recently, a modified 3D elliptical centric acquisition was proposed to facilitate 2D-PF and homodyne reconstruction on an undersampled phase/slice-encoding plane. In this work we hypothesized that this 2D-PF technique can be combined with 2D-SENSE to achieve a greater acceleration factor than what each method can provide separately. Reconstruction of data whereby SENSE and PF are applied along the same axes is described. Contrast-enhanced MR angiography (CE-MRA) results from experiments using four receiver coils in phantom and volunteer studies are shown. In 11 volunteer studies, the SENSE-PF-homodyne technique using sevenfold acceleration (4x SENSE, 1.7x PF) consistently provided high-diagnostic-quality images with near 1-mm isotropic resolution in acquisition times of <20 s.

Contrast-enhanced MR angiography of the peripheral vasculature with a continuously moving table and modified elliptical centric acquisition.

This study was approved by the institutional review board and was HIPAA compliant. All subjects provided written informed consent, and subject confidentiality was protected. The purpose of this study was to prospectively evaluate the feasibility of integrating a modified elliptical centric (EC) acquisition with a continuously moving table technique to acquire high-spatial-resolution contrast material-enhanced magnetic resonance (MR) angiograms of the peripheral vasculature. Incorporation of two-dimensional homodyne reconstruction modified the EC view order, allowing improved spatial resolution per unit time while retaining the advantage of venous suppression intrinsic to the EC technique. Spatial resolution was dynamically improved when the table reached the distal-most station. The modified view order provided improved spatial resolution in phantom examinations compared with that in standard examinations. Peripheral MR angiograms were generated in a group of 13 volunteers (eight women; five men; age range, 51-72 years; mean age, 58.5 years +/- 7.9 [standard deviation]) at 1.5 T. Four arterial regions were evaluated on a five-point scale (scores ranged from 0 to 4; a score of 4 was considered excellent); venous suppression was also evaluated. The mean arterial scores exceeded 3.0 for all regions. There was no venous signal or only superficial venous signal in 10 of the 13 cases.