Ga-68 Prostate-Specific Membrane Antigen PET/CT is a new tool for the assessment of prostate cancer. Standard imaging time is 60 minutes post injection of radiotracer. At 60 minutes, there is physiologic accumulation of radiotracer in the urinary bladder which may cause some lesions in its vicinity to be obscured. Our aim is to determine if early imaging at 3 minutes in addition to standard imaging at 60 minutes can improve the detection of PSMA-avid lesions. A retrospective review of 167 consecutive patients was conducted. Overall, 115 patients (68.9%) were ruled to have prostate cancer based on imaging as seen on early or standard PET/CT images. In 106/115 (64%), the lesions were detected on both early and standard imaging; in 8/115 (6.9%), the lesions were only detected on early imaging; in 1/115 (0.6%) the lesion was detected only on standard imaging. The addition of early imaging significantly improved the overall detection rate of PSMA-avid lesions (p = 0.039). The ratio of patients with lesions detected on early imaging but not on standard imaging in restaging group was 7/88 and was higher than that in staging group 1/79 (p = 0.043). We recommend early imaging in addition to the standard imaging in Ga-68 PSMA PET/CT, particularly in patients presenting for restaging of prostate cancer.
This study describes the application of dynamic gadolinium-enhanced magnetic resonance (MR) imaging and MR angiography in the diagnosis and evaluation of the physiology of renal artery stenosis (RAS) before and after angioplasty. The MR imaging findings are discussed and compared to those of renal arteriography. MR time intensity curves of the renal cortex and medulla are obtained. Dynamic gadolinium-enhanced and angiographic MR data were abnormal in the setting of RAS and improved after angioplasty. The diagnosis of RAS could be made by visual inspection of MR dynamic images or MR angiographic images alone. Dynamic MR provides cross-sectional physiologic imaging data that compliments MR angiographic data. The role of dynamic gadolinium-enhanced MR in the evaluation of renovascular hypertension requires further investigation.
To develop recommendations regarding imaging studies for the diagnosis and follow-up of patients with axial forms of ankylosing spondylitis (AS) seen in everyday practice. Evidence from the literature and expert opinion were used to develop the recommendations. Using the Delphi consensus procedure, a scientific committee selected five areas of interest, about which scientific evidence was sought by searching Medline and the databases maintained by the French Society for Rheumatology, European League against Rheumatism, and American College of Rheumatology. Based on this evidence, a panel of experienced rheumatologists drafted recommendations, using expert opinion if needed to supplement gaps in evidence. For each recommendation, the level of evidence and the extent of agreement among the experts were specified. The five areas of interest dealt with the usefulness of imaging studies for the diagnosis, follow-up, prognostic evaluation, and assessment of treatment responses in patients with AS. The literature search retrieved 144 articles based on titles and abstracts. After elimination of articles that did not include an analysis of the radiological evaluation of AS, 73 articles were left for review. Eight recommendations were drafted then validated by having all panel participants vote during a final meeting. Eight recommendations about the use of imaging studies in patients with AS were developed. They can be expected to improve clinical practice uniformity and, in the longer term, to optimize the management of patients with AS.
Emerging evidence suggests that skeletal muscle cells (SKMC) play critical roles in the defective angiogenic response in diabetic critical limb ischemia. However, the molecular mechanisms linking skeletal muscle to impaired angiogenic properties of endothelial cells (EC) remain unidentified. The current study investigates how muscle-specific miR-499-5p may impair EC function in diabetic ischemic limbs. Eight-week-old, male C57BL/6 J, db/ + and db/db mice were employed. Hind limb ischemia was established by unilateral ligation of the left femoral artery, and blood flow recovery was monitored using Laser Doppler perfusion imaging (LDPI). ECs and SKMCs were isolated from sham or ischemic hind limbs (IHL). SKMC-derived small extracellular vesicles (SKMC-sEVs) were isolated from the culture medium of SKMCs by ultra-centrifugation. miR-499-5p level was markedly increased in SKMCs and unexpectedly in ECs from hindlimb of db/db mice. Ischemic injury further enhanced miR-499-5p levels in ECs from IHL of db/db mice. Angiogenic activity was reduced in ECs from IHL of db/db mice and in miR-499-5p-overexpressing ECs. Intramuscular injection of lentiviral-anti-miR-499-5p improved blood perfusion and angiogenesis in IHL of db/db mice. Mechanistically, we found that diabetic SKMC sEVs carried high levels of miR-499-5p and transferred miR-499-5p to ECs. Intramuscular injection of diabetic SKMC-sEVs repressed IHL recovery in wildtype mice. Blocking sEV biosynthesis/release by GW4869 markedly improved neovascularization and blood perfusion in IHL of db/db mice. We identified that SRY (Sex-Determining Region Y)-Box 6 (SOX6) is a direct downstream target of miR-499-5p. Silencing of SOX6 suppressed release of proangiogenic factors from ECs. Targeted reduction of miR-499-5p significantly enhanced SOX6 levels in ECs from IHL of db/db mice. Finally, overexpression of SOX6 improved the angiogenic property of ECs from IHL of db/db mice. SKMC-sEV-mediated transfer of myo-miR-499-5p and subsequent suppression of SOX6 plays a critical role in diabetes-impaired neovascularization in IHL of db/db mice. Targeting miR-499-5p-mediated pathogenic communication between SKMCs and ECs may be a novel therapeutic avenue for critical limb ischemia in diabetic patients.
Echocardiography is the key tool for the diagnosis and evaluation of aortic stenosis. Because clinical decision-making is based on the echocardiographic assessment of its severity, it is essential that standards are adopted to maintain accuracy and consistency across echocardiographic laboratories. Detailed recommendations for the echocardiographic assessment of valve stenosis were published by the European Association of Echocardiography and the American Society of Echocardiography in 2009. In the meantime, numerous new studies on aortic stenosis have been published with particular new insights into the difficult subgroup of low gradient aortic stenosis making an update of recommendations necessary. The document focuses in particular on the optimization of left ventricular outflow tract assessment, low flow, low gradient aortic stenosis with preserved ejection fraction, a new classification of aortic stenosis by gradient, flow and ejection fraction, and a grading algorithm for an integrated and stepwise approach of artic stenosis assessment in clinical practice.
Cardiac point-of-care ultrasound has the potential to improve patient care, but its application to children requires consideration of anatomic and physiologic differences from adult populations, and corresponding technical aspects of performance. This document is the product of an American Society of Echocardiography task force composed of representatives from pediatric cardiology, pediatric critical care medicine, pediatric emergency medicine, pediatric anesthesiology, and others, assembled to provide expert guidance. This diverse group aimed to identify common considerations across disciplines to guide evolution of indications, and to identify common requirements and infrastructure necessary for optimal performance, training, and quality assurance in the practice of cardiac point-of-care ultrasound in children. The recommendations presented are intended to facilitate collaboration among subspecialties and with pediatric echocardiography laboratories by identifying key considerations regarding (1) indications, (2) imaging recommendations, (3) training and competency assessment, and (4) quality assurance.
Sarcoidosis staging primarily has relied on the Scadding chest radiographic system, although chest CT imaging is finding increased clinical use. Whether standardized chest CT scan assessment provides additional understanding of lung function beyond Scadding stage and demographics is unknown and the focus of this study. We used National Heart, Lung, and Blood Institute study Genomics Research in Alpha-1 Antitrypsin Deficiency and Sarcoidosis (GRADS) cases of sarcoidosis (n = 351) with Scadding stage and chest CT scans obtained in a standardized manner. One chest radiologist scored all CT scans with a visual scoring system, with a subset read by another chest radiologist. We compared demographic features, Scadding stage and CT scan findings, and the correlation between these measures. Associations between spirometry and diffusing capacity of the lungs for carbon monoxide (Dlco) results and CT scan findings and Scadding stage were determined using regression analysis (n = 318). Agreement between readers was evaluated using Cohen's κ value. CT scan features were inconsistent with Scadding stage in approximately 40% of cases. Most CT scan features assessed on visual scoring were associated negatively with lung function. Associations persisted for FEV1 and Dlco when adjusting for Scadding stage, although some CT scan feature associations with FVC became insignificant. Scadding stage was associated primarily with FEV1, and inclusion of CT scan features reduced significance in association between Scadding stage and lung function. Multivariable regression modeling to identify radiologic measures explaining lung function included Scadding stage for FEV1 and FEV1 to FVC ratio (P < .05) and marginally for Dlco (P < .15). Combinations of CT scan measures accounted for Scadding stage for FVC. Correlations among Scadding stage and CT scan features were noted. Agreement between readers was poor to moderate for presence or absence of CT scan features and poor for degree and location of abnormality. In this study, CT scan features explained additional variability in lung function beyond Scadding stage, with some CT scan features obviating the associations between lung function and Scadding stage. Whether CT scan features, phenotypes, or endotypes could be useful for treating patients with sarcoidosis needs more study.
The change of brain lesion load, measured on T2-weighted magnetic resonance imaging (MRI) using computer-assisted techniques, is a widely used secondary endpoint for phase III clinical trials in multiple sclerosis (MS). Collection, transfer, and analysis of the electronic data across multiple centers have all proved challenging and give rise to potential errors. However, many new acquisition schemes and postprocessing techniques have been developed; these may reduce scan times and result in better lesion conspicuity or lessen the human interaction needed for data analysis. This review considers many aspects of the use of MRI in clinical trials for MS and provides international consensus guidelines, derived from a task force of the European Magnetic Resonance Networks in Multiple Sclerosis (MAGNIMS) together with a group of North American experts. The main points considered are the organization of correctly powered trials and selection of participating sites; the appropriate choice of pulse sequences and image acquisition protocol given the current state of technology; quality assurance for data acquisition and analysis; accuracy and reproducibility of lesion load assessments; and the potential for the application of quantitative methods to other MRI-derived measures of disease burden.
Allostatic load (AL) is a measurement of physiological burden of chronic stress, operationalized using a composite score derived from biomarkers from multiple physiologic systems. The relationship between AL and anthracycline cardiotoxicity is unclear. We included consecutive adult patients who underwent anthracycline-based chemotherapy from 2016 to 2019 for any type of cancer. Patients with preexisting heart failure and lack of AL score measures were excluded from the analysis. A composite AL score was calculated using 9 biomarkers tested before initiating chemotherapy. The end point was the development of cardiotoxicity (defined as clinical heart failure or drop in left ventricular ejection fraction≥10% to <50%). A total of 718 patients were included in the analysis (29% Non-Hispanic White, 31% Non-Hispanic Black, 40% Hispanic). The mean AL score was 2.4±1.4 and it was significantly higher in Non-Hispanic Black and Hispanic patients compared with Non-Hispanic White patients (2.5±1.3 in Non-Hispanic Black versus 2.4±1.3 in Hispanic versus 2.1±1.5 in Non-Hispanic White, P=0.031). In patients who developed cardiotoxicity, AL score was significantly higher than patients without cardiotoxicity (2.7±1.4 versus 2.3±1.3, P=0.006). AL score was independently associated with incident anthracycline cardiotoxicity after adjusting for race and ethnicity, age, sex, cardiovascular risk factors, anthracycline dose, baseline left ventricular ejection fraction, cancer type, and cancer metastasis (hazard ratio 1.20 per 1 AL score increase [95% CI, 1.02-1.43], P=0.033). AL score remained significantly associated with anthracycline cardiotoxicity after additional adjustment of social determinants of health. AL score can be a potential important prognostic marker in the prediction of cardiotoxicity in patients with cancer undergoing cardiotoxic treatment independent of social determinants of health.
Mesh placement during repair of acutely incarcerated ventral and groin hernias is associated with high rates of surgical site infection (SSI). The utility of preoperative computed tomography (CT) in this setting is unclear. We hypothesized that CT evidence of bowel wall compromise would predict SSI while accounting for physiologic parameters. We performed a 4-year retrospective cohort analysis of 50 consecutive patients who underwent mesh repair of acutely incarcerated ventral or groin hernias. We analyzed chronic disease burden, acute illness severity, CT findings, operative management, and herniorrhaphy-specific outcomes within 180 days. The primary outcome was SSI by the Centers for Disease Control and Prevention criteria. Multiple logistic regression was performed to identify independent predictors of SSI. Eighty-four percent of all patients were American Society of Anesthesiologists class III or IV, 28% were active smokers, and mean body mass index (BMI) was 35 kg/m. Fifty-four percent had ventral hernias, 40% had inguinal hernias, and 6% had femoral or combined inguinal/ femoral hernias. Seventy percent of preoperative CT scans had features suggesting bowel compromise, abdominal free fluid, or fluid in the hernia sac. Surgical site infection occurred in 32% of all patients (8% superficial, 24% deep or organ/space). The strongest predictors of SSI were CT evidence of fluid in the hernia sac (odds ratio [OR], 8.3; 95% confidence interval [CI], 1.7-41), initial heart rate 90 beats/min or greater (OR, 6.3; 95% CI, 1.1-34), and BMI 35 kg/m or greater (OR, 5.8; 95% CI, 1.2-28). Surgical site infection rates were significantly higher among patients who had CT evidence of fluid in the hernia sac (56% vs. 19%, p = 0.012). More than half of all patients with CT scan evidence of fluid in the hernia sac developed an SSI. Computed tomography evidence of fluid in the hernia sac was the strongest predictor of SSI, followed by heart rate and BMI. Together, these parameters identify high-risk patients for whom better strategies are needed to avoid SSI without sacrificing durability. Prognostic study, level III; Therapeutic, level IV.
Background: Ventilator associated pneumonia (VAP) is defined by the American College of Surgeons Trauma Quality Improvement Program (ACS TQIP) using laboratory findings, pathophysiologic signs/symptoms, and imaging criteria. However, many critically ill trauma patients meet the non-specific laboratory and sign/symptom thresholds for VAP, so the TQIP designation of VAP depends heavily upon imaging evidence. We hypothesized that physician opinions widely vary regarding chest radiograph findings significant for VAP. Patients and Methods: The TQIP Spring 2021 Benchmark Report (BR) was used to identify 14 patients with VAP at an academic Level 1 Trauma Center. Critically ill trauma patients (n = 7) who spent at least four days intubated and met TQIP's laboratory and sign/symptom thresholds for VAP but did not appear as VAPs on the BR comprised the control group. For each deidentified patient, four successive chest radiographic images were compiled and arranged chronologically. Cases and controls were randomly arranged in digital format. Blinded physicians (n = 27) were asked to identify patients with VAP based solely on imaging evidence. Results: Radiographic evidence of VAP was highly subjective (Krippendorff α = 0.134). Among physicians of the same job description, inter-rater reliability remained low (α = 0.137 for trauma attending physicians; α = 0.141 for trauma fellows; α = 0.271 for radiologists). When majority judgment was compared to the TQIP BR, there was disagreement between the two tests (Cohen κ = -0.071; sensitivity, 64.3%; specificity, 28.6%). Conclusions: Current definitions of VAP rely on subjective imaging interpretation and ignore the reality that there are numerous explanations for opacities on CXR. The inconsistency of physicians' imaging interpretation and protean physiologic findings for VAP in trauma patients should preclude the current definition of VAP from being used as a quality improvement metric in TQIP.
The 2015 Magnetic Resonance Imaging in Multiple Sclerosis and 2016 Consortium of Multiple Sclerosis Centres guidelines on the use of MRI in diagnosis and monitoring of multiple sclerosis made an important step towards appropriate use of MRI in routine clinical practice. Since their promulgation, there have been substantial relevant advances in knowledge, including the 2017 revisions of the McDonald diagnostic criteria, renewed safety concerns regarding intravenous gadolinium-based contrast agents, and the value of spinal cord MRI for diagnostic, prognostic, and monitoring purposes. These developments suggest a changing role of MRI for the management of patients with multiple sclerosis. This 2021 revision of the previous guidelines on MRI use for patients with multiple sclerosis merges recommendations from the Magnetic Resonance Imaging in Multiple Sclerosis study group, Consortium of Multiple Sclerosis Centres, and North American Imaging in Multiple Sclerosis Cooperative, and translates research findings into clinical practice to improve the use of MRI for diagnosis, prognosis, and monitoring of individuals with multiple sclerosis. We recommend changes in MRI acquisition protocols, such as emphasising the value of three dimensional-fluid-attenuated inversion recovery as the core brain pulse sequence to improve diagnostic accuracy and ability to identify new lesions to monitor treatment effectiveness, and we provide recommendations for the judicious use of gadolinium-based contrast agents for specific clinical purposes. Additionally, we extend the recommendations to the use of MRI in patients with multiple sclerosis in childhood, during pregnancy, and in the post-partum period. Finally, we discuss promising MRI approaches that might deserve introduction into clinical practice in the near future.
Traumatic brain injury (TBI) often precedes the onset of epileptic (ES) or psychogenic nonepileptic seizures (PNES) with depression being a common comorbidity. The relationship between depression severity and quality of life (QOL) may be related to resting-state network complexity. We investigated these relationships in adults with TBI-only, TBI + ES, or TBI + PNES using Sample Entropy (SampEn), a measure of physiologic signals complexity. Adults with TBI-only (n = 60), TBI + ES (n = 21), or TBI + PNES (n = 56) completed the Beck Depression Inventory-II (BDI-II; depression symptom severity) and QOL in Epilepsy (QOLIE-31) assessments and underwent resting-state functional magnetic resonance imaging (rs-fMRI). SampEn values derived from six resting state functional networks were calculated per participant. Effects of group, network, and group-by-network-interactions for SampEn were investigated with a mixed-effects model. We examined relationships between BDI-II, QOL, and SampEn of each of the networks. Groups did not differ in age, but there was a higher proportion of women with TBI + PNES (p = 0.040). TBI + ES and TBI-only groups did not differ in BDI-II or QOLIE-31 scores, while the TBI + PNES group scored worse on both measures. The fixed effects of the model revealed significant differences in SampEn values across networks (lower SampEn for the frontoparietal network compared to other networks). The likelihood ratio test for group-by-network-interactions was significant (p = 0.033). BDI-II was significantly negatively associated with Overall QOL scale scores in all groups, and significantly negatively associated with network SampEn values only in the TBI + PNES group. Only TBI + PNES had significant relationships between depression symptom severity and network SampEn values indicating that the resting state network complexity is related to depression severity in this group but not in TBI + ES or TBI-only. The brain has a complex network of internal connections. How well these connections work may be affected by TBI and seizures and may underlie mental health symptoms including depression; the worse the depression, the worse the quality of life. Our study compared brain organization in people with TBI, people with epilepsy after TBI, and people with nonepileptic seizures after TBI. Only people with nonepileptic seizures after TBI showed a relationship between how organized their brain connections were and how bad was their depression. We need to better understand these relationships to develop more impactful, effective treatments.
This study was performed to assess the usefulness of preoperative thin-section CT alone and in combination with physiologic measurements in emphysema patients being evaluated for lung volume reduction surgery. Six 1-mm collimation sections through the chest were obtained in 20 patients being evaluated for lung volume reduction surgery. Extent and severity of emphysema were assessed by visually scoring the images. CT scores ranged from 0 to 144. Inspiratory resistance was measured in 12 of 20 patients and was also used to discriminate between responders (change in forced expiratory volume in 1 sec, > or = 150 ml after surgery) and nonresponders (change in forced expiratory volume in 1 sec, < 150 ml after surgery). Four of 20 patients with mild emphysema as revealed by thin-section CT (scores of < 50) did not improve lung function after lung volume reduction surgery. Eight of the remaining 16 patients with moderate to severe emphysema as revealed by thin-section CT (scores of > 50) underwent inspiratory resistance measurement. Those seven patients whose inspiratory resistance measurement exceeded 8.5 cm H2O/l per second did not respond favorably to lung volume reduction surgery (change in forced expiratory volume in 1 sec, < 150 ml). The remaining five patients whose inspiratory resistance measurement was less than 8.5 cm H2O/l per second responded favorably to lung volume reduction surgery. Thus, only five of the 20 patients showed improvement in forced expiratory volume in 1 sec after surgery. Our data suggest that among patients with moderate to severe emphysema who are being examined for lung volume reduction surgery, the combination of radiologic and physiologic assessment is more accurate for predicting a favorable response to lung volume reduction surgery than radiologic assessment alone. However, in patients with chronic obstructive pulmonary disease by the American Thoracic Society criteria, mild emphysema as revealed on thin-section CT virtually precludes further workup because these patients are unlikely to respond favorably to lung volume reduction surgery.
Internal fixation is an accepted treatment for displaced fractures of the calcaneus. Operative intervention in older patients, however, is traditionally discouraged in the literature. The purpose of this study was to compare the outcomes of internal fixation of intra-articular fractures of the calcaneus on the basis of patient age. One hundred and seventy-five patients (191 fractures) who underwent internal fixation between 1992 and 2007 for a displaced, intra-articular calcaneal fracture were identified. The American Society of Anesthesiologists score, the fracture pattern, and the mechanism of injury were recorded. Each patient was contacted to complete a follow-up survey from which clinical outcome scores were calculated. One hundred and forty-six patients with 158 fractures were available for follow-up and were divided into two groups for comparison. Group I consisted of 108 fractures in patients who were less than fifty years old. Group II was composed of fractures in fifty patients who were fifty years of age or older. The mean duration of follow-up was 8.98 years. The average patient age was thirty-six years for Group I and fifty-eight years for Group II. The average adjusted American Orthopaedic Foot & Ankle Society score was 64 for Group I and 75 for Group II. The mean calcaneal fracture scoring system score was 66 for Group I, and 76 for Group II. Similarly, the average Foot Function Index was 24 and 15 for Groups I and II, respectively. Each clinical outcome measure suggests significantly better outcomes for Group II as compared with Group I (all p < 0.05). Overall, the complication rates were similar between groups. Conversion to subtalar fusion was 15% for Group I and 8% for Group II. In this series, outcomes of older patients are at least equivalent to those of younger patients undergoing internal fixation for an intra-articular calcaneal fracture. Operative intervention appears to be a reasonable option for displaced calcaneal fractures in older patients. Physiologic age should be considered when evaluating older patients, and individualized treatment plans remain critical because patients with low physical demands or who have medical complications may be better candidates for nonoperative treatment. Prospective studies are needed in this area.
Globally, intracranial pressure (ICP) monitoring use in severe traumatic brain injury (sTBI) is inconsistent and susceptible to resource limitations and clinical philosophies. For situations without monitoring, there is no published comprehensive management algorithm specific to identifying and treating suspected intracranial hypertension (SICH) outside of the one ad hoc Imaging and Clinical Examination (ICE) protocol in the Benchmark Evidence from South American Trials: Treatment of Intracranial Pressure (BEST:TRIP) trial. As part of an ongoing National Institutes of Health (NIH)-supported project, a consensus conference involving 43 experienced Latin American Intensivists and Neurosurgeons who routinely care for sTBI patients without ICP monitoring, refined, revised, and augmented the original BEST:TRIP algorithm. Based on BEST:TRIP trial data and pre-meeting polling, 11 issues were targeted for development. We used Delphi-based methodology to codify individual statements and the final algorithm, using a group agreement threshold of 80%. The resulting CREVICE (Consensus REVised ICE) algorithm defines SICH and addresses both general management and specific treatment. SICH treatment modalities are organized into tiers to guide treatment escalation and tapering. Treatment schedules were developed to facilitate targeted management of disease severity. A decision-support model, based on the group's combined practices, is provided to guide this process. This algorithm provides the first comprehensive management algorithm for treating sTBI patients when ICP monitoring is not available. It is intended to provide a framework to guide clinical care and direct future research toward sTBI management. Because of the dearth of relevant literature, it is explicitly consensus based, and is provided solely as a resource (a "consensus-based curbside consult") to assist in treating sTBI in general intensive care units in resource-limited environments.
We prospectively assessed the reproducibility of a novel low-dose single-volume dynamic computed tomography (CT) myocardial blood flow measurement technique. Thirty-four pairs of measurements were made under rest and stress conditions in 13 swine (54.3 ± 12.3 kg). One or two acquisition pairs were acquired in each animal with a 10-min delay between each pair. Contrast (370 mgI/mL; 0.5 mL/kg) and a diluted contrast/saline chaser (0.5 mL/kg; 30:70 contrast/saline) were injected peripherally at 5 mL/s, followed by bolus tracking and acquisition of a single volume scan (100 kVp; 200 mA) with a 320-slice CT scanner. Bolus tracking and single volume scan data were used to derive perfusion in mL/min/g using a first-pass analysis model; the coronary perfusion territories of the left anterior descending (LAD), left circumflex (LCx), and right coronary artery (RCA) were automatically assigned using a previously validated minimum-cost path technique. The reproducibility of CT myocardial perfusion measurement within the LAD, LCx, RCA, and the whole myocardium was assessed via regression analysis. The average CT dose index (CTDI) of perfusion measurement was recorded. The repeated first (Pmyo1) and second (Pmyo2) single-volume CT perfusion measurements were related by Pmyo2 = 1.01Pmyo1 - 0.03(ρ = 0.96; RMSE = 0.08 mL/min/g; RMSE = 0.07 mL/min/g) for the whole myocardium, and by Preg2 = 0.86Preg1 + 0.13(ρ = 0.87; RMSE = 0.31 mL/min/g; RMSE = 0.29 mL/min/g) for the LAD, LCx, and RCA perfusion territories. The average CTDI of the single-volume CT perfusion measurement was 10.5 mGy. The single-volume CT blood flow measurement technique provides reproducible low-dose myocardial perfusion measurement using only bolus tracking data and a single whole-heart volume scan. The single-volume CT blood flow measurement technique is a noninvasive tool that reproducibly measures myocardial perfusion and provides coronary CT angiograms, allowing for simultaneous anatomic-physiologic assessment of myocardial ischemia. A low-dose single-volume dynamic CT myocardial blood flow measurement technique is reproducible. Motion misregistration artifacts are eliminated using a single-volume CT perfusion technique. This technique enables combined anatomic-physiologic assessment of coronary artery disease.
Treatment of tibiofibular syndesmotic ankle injury remains controversial in regard to the best method, although surgeons agree that the goal of treatment is reduction and operative stabilization. Ideally, the implant should stabilize the syndesmosis and allow physiologic micromotion and early mobilization, and conventional screws are limited in this regard. We reviewed use of the Ankle TightRope(®) fixation device for repair of syndesmotic injuries. From April to September 2006, 16 patients with evidence of syndesmotic injury were treated by means of ankle fracture open reduction with internal fixation, combined with use of the Ankle TightRope(®) device for repair of the syndesmosis. The mean age of the 16 patients was 36.6 ± 16.71 (range 15 to 69) years; they were followed up for at least 2 years. Mean follow-up duration was 26 ± 3.94 (range 24 to 38) months. The mean American Orthopaedic Foot and Ankle Society score at 2-year follow-up was 86.88 ± 11.49 (range 48 to 100). The mean time to full weight-bearing was 4.5 ± 0.87 weeks. Two (12.5%) patients had postoperative superficial wound infections, each of which was treated with oral antibiotics. One (6.25%) patient had the TightRope(®) removed because of irritation from the knot. There was no failure of syndesmotic fixation, despite early weight-bearing in the postoperative phase. The results of this case series indicate that tibiofibular syndesmosis repair with the Ankle TightRope(®) yields satisfactory results.
With the recent advances in medical imaging, three-dimensional anatomical and metabolic images of the brain are now available through MR/CT and PET/SPECT imaging modalities. Computerized multi-modality three-dimensional brain image registration and analysis can provide important correlated information for improving diagnosis and studying the pathology of disease. Such analysis may also provide help in planning brain surgery. Further, an anatomical model based quantification and analysis of internal structure can be used to develop a computerized anatomical atlas. Conventional anatomical atlases provide rigid spatial distribution of internal structures extracted from a single subject. The proposed computerized anatomical atlas provides probabilistic spatial distributions which can be easily updated to incorporate the variability of brain structures of subjects selected from pre-defined groups. This paper first presents a review of the current trends in knowledge-based segmentation, labeling, and analysis of MR brain images and then describes the Principal Axes Transformation based registration of three-dimensional MR brain images to develop composite models of selected internal brain structures. The composite models can be used as a computerized anatomical atlas in model-based segmentation and labeling of MR brain images. Three-dimensional labeled MR images of the brain can also be registered and correlated with PET images for analyzing the metabolic activity in the anatomically selected volume of interest. On the other hand, a volume of interest can be selected using the metabolic information and then analyzed for correlated anatomical information using the registered MR-PET images.
Fibrous dysplasia of bone/McCune-Albright syndrome (Polyostotic FD/MAS; OMIM#174800) is a crippling skeletal disease caused by gain-of-function mutations of Gs α. Enhanced bone resorption is a recurrent histological feature of FD and a major cause of fragility of affected bones. Previous work suggests that increased bone resorption in FD is driven by RANKL and some studies have shown that the anti-RANKL monoclonal antibody, denosumab, reduces bone turnover and bone pain in FD patients. However, the effect of RANKL inhibition on the histopathology of FD and its impact on the natural history of the disease remain to be assessed. In this study, we treated the EF1α-Gs αR201C mice, which develop an FD-like phenotype, with an anti-mouse RANKL monoclonal antibody. We found that the treatment induced marked radiographic and microscopic changes at affected skeletal sites in 2-month-old mice. The involved skeletal segments became sclerotic due to the deposition of new, highly mineralized bone within developing FD lesions and showed a higher mechanical resistance compared to affected segments from untreated transgenic mice. Similar changes were also detected in older mice with a full-blown skeletal phenotype. The administration of anti-mouse RANKL antibody arrested the growth of established lesions and, in young mice, prevented the appearance of new ones. However, after drug withdrawal, the newly formed bone was remodelled into FD tissue and the disease progression resumed in young mice. Taken together, our results show that the anti-RANKL antibody significantly affected the bone pathology and natural history of FD in the mouse. Pending further work on the prevention and management of relapse after treatment discontinuation, our preclinical study suggests that RANKL inhibition may be an effective therapeutic option for FD patients. © 2019 American Society for Bone and Mineral Research.