Regulation of Synovial γδ T Cell Ligand Expression by Mitochondrial Reactive Oxygen Species and Gasdermin-D.

γδ T cells reside at mucosal and epithelial barriers, and they often accumulate at sites of inflammation, both infectious and autoimmune, as well as in certain tumors. However, progress in understanding their function is considerably hampered by a lack of full understanding of the ligands recognized by TCR-γδ and how expression of these ligands is regulated. We recently developed a soluble human TCR-γδ (Vγ9Vδ1) tetramer from a synovial γδ T cell clone of a Lyme arthritis patient and observed that it stains monocytes activated by Borrelia burgdorferi. Those findings are extended in the current study to further examine the physiological regulation of ligand expression on monocytes. The TCR-γδ ligand is induced by a variety of TLR agonists and requires NF-κB activation. Of particular interest is that ligand expression also requires caspase activation of the inflammasome and is dependent on active metabolism, mitochondrial reactive oxygen species, and activation of gasdermin-D. Consistent with these observations, the TCR-γδ ligand is expressed by a subset of metabolically active CD14+CD16+ monocytes and colocalizes intracellularly with mitochondria. The findings suggest a model in which synovial γδ T cell ligand is a self-antigen whose surface expression is increased by inflammatory conditions and mitochondrial stress.

Intra-patient variability of iodine quantification across different dual-energy CT platforms: assessment of normalization techniques.

OBJECTIVES: To investigate intra-patient variability of iodine concentration (IC) between three different dual-energy CT (DECT) platforms and to test different normalization approaches. METHODS: Forty-four patients who underwent portal venous phase abdominal DECT on a dual-source (dsDECT), a rapid kVp switching (rsDECT), and a dual-layer detector platform (dlDECT) during cancer follow-up were retrospectively included. IC in the liver, pancreas, and kidneys and different normalized ICs (NICPV:portal vein; NICAA:abdominal aorta; NICALL:overall iodine load) were compared between the three DECT scanners for each patient. A longitudinal mixed effects analysis was conducted to elucidate the effect of the scanner type, scan order, inter-scan time, and contrast media amount on normalized iodine concentration. RESULTS: Variability of IC was highest in the liver (dsDECT vs. dlDECT 28.96 (14.28-46.87) %, dsDECT vs. rsDECT 29.08 (16.59-62.55) %, rsDECT vs. dlDECT 22.85 (7.52-33.49) %), and lowest in the kidneys (dsDECT vs. dlDECT 15.76 (7.03-26.1) %, dsDECT vs. rsDECT 15.67 (8.86-25.56) %, rsDECT vs. dlDECT 10.92 (4.92-22.79) %). NICALL yielded the best reduction of IC variability throughout all tissues and inter-scanner comparisons, yet did not reduce the variability between dsDECT vs. dlDECT and rsDECT, respectively, in the liver. The scanner type remained a significant determinant for NICALL in the pancreas and the liver (F-values, 12.26 and 23.78; both, p < 0.0001). CONCLUSIONS: We found tissue-specific intra-patient variability of IC across different DECT scanner types. Normalization mitigated variability by reducing physiological fluctuations in iodine distribution. After normalization, the scanner type still had a significant effect on iodine variability in the pancreas and liver. CLINICAL RELEVANCE STATEMENT: Differences in iodine quantification between dual-energy CT scanners can partly be mitigated by normalization, yet remain relevant for specific tissues and inter-scanner comparisons, which should be taken into account at clinical routine imaging. KEY POINTS: • Iodine concentration showed the least variability between scanner types in the kidneys (range 10.92-15.76%) and highest variability in the liver (range 22.85-29.08%). • Normalizing tissue-specific iodine concentrations against the overall iodine load yielded the greatest reduction of variability between scanner types for 2/3 inter-scanner comparisons in the liver and for all (3/3) inter-scanner comparisons in the kidneys and pancreas, respectively. • However, even after normalization, the dual-energy CT scanner type was found to be the factor significantly influencing variability of iodine concentration in the liver and pancreas.

The association between use of ambient voice technology documentation during primary care patient encounters, documentation burden, and provider burnout.

BACKGROUND: The burden of documentation in the electronic medical record has been cited as a major factor in provider burnout. The aim of this study was to evaluate the association between ambient voice technology, coupled with natural language processing and artificial intelligence (DAX™), on primary care provider documentation burden and burnout. METHODS: An observational study of 110 primary care providers within a community teaching health system. The primary objectives were to determine the association between DAX™ usage and provider burnout scores on the Oldenburg Burnout Inventory (OLBI) as well as the effect on documentation time per patient encounter (minutes). RESULTS: The completion rate for the survey was 75% (83/110) and high DAX™ use (>60% of encounters) was seen in 28% of providers (23/83). High DAX™ use was associated with significantly less burnout on the OLBI disengagement sub-score (MD [Mean Difference] -2.1; 95% confidence interval [CI] -3.8 to -0.4) but not the OLBI disengagement sub-score (-1.0; 95% CI -2.9 to 1.0) or total score (MD -3.0; 95% CI -6.4 to 0.3). Nineteen providers with high implementation of DAX™ had pre and postimplementation data on documentation time per encounter. After DAX™ implementation average documentation time in notes per encounter was significantly reduced by 28.8% (1.8 min; 95% CI 1.4-2.2). CONCLUSIONS: The use of ambient voice technology during patient encounters was associated with significantly reduced documentation burden and primary care provider disengagement but not total provider burnout scores.

Positron Emission Tomography/Magnetic Resonance Imaging (PET/MRI) Versus the Standard of Care Imaging in the Diagnosis of Peritoneal Carcinomatosis.

OBJECTIVE: To compare positron emission tomography (PET)/magnetic resonance imaging (MRI) to the standard of care imaging (SCI) for the diagnosis of peritoneal carcinomatosis (PC) in primary abdominopelvic malignancies. SUMMARY BACKGROUND DATA: Identifying PC impacts prognosis and management of multiple cancer types. METHODS: Adult subjects were prospectively and consecutively enrolled from April 2019 to January 2021. Inclusion criteria were: 1) acquisition of whole-body contrast-enhanced (CE) 18F-fluorodeoxyglucose PET/MRI, 2) pathologically confirmed primary abdominopelvic malignancies. Exclusion criteria were: 1) greater than 4 weeks interval between SCI and PET/MRI, 2) unavailable follow-up. SCI consisted of whole-body CE PET/computed tomography (CT) with diagnostic quality CT, and/or CE-CT of the abdomen and pelvis, and/or CE-MRI of the abdomen±pelvis. If available, pathology or surgical findings served as the reference standard, otherwise, imaging followup was used. When SCI and PET/MRI results disagreed, medical records were checked for management changes. Follow-up data were collected until August 2021. RESULTS: One hundred sixty-four subjects were included, 85 (52%) were female, and the median age was 60 years (interquartile range 50-69). At a subject level, PET/MRI had higher sensitivity (0.97, 95% CI 0.86-1.00) than SCI (0.54, 95% CI 0.37-0.71), P < 0.001, without a difference in specificity, of 0.95 (95% CI 0.90-0.98) for PET/MRI and 0.98 (95% CI 0.93-1.00) for SCI, P » 0.250. PET/MRI and SCI results disagreed in 19 cases. In 5/19 (26%) of the discordant cases, PET/MRI findings consistent with PC missed on SCI led to management changes. CONCLUSION: PET/MRI improves detection of PC compared with SCI which frequently changes management.

Renal lesion characterization: clinical utility of single-phase dual-energy CT compared to MRI and dual-phase single-energy CT.

OBJECTIVES: To assess the impact of dual-energy CT (DECT) utilization in practice by measuring the readers' confidence, the need for additional image requests, and diagnostic performance in renal lesion assessment, compared to single-energy CT (SECT) using contrast-enhanced MRI to establish the reference standard. MATERIALS AND METHODS: Sixty-nine patients (M/F = 47/22) who underwent a dual-phase renal SECT (n = 34) or DECT (n = 35) and had a contrast-enhanced MRI within 180 days were retrospectively collected. Three radiologists assessed images on different sessions (SECT, DECT, and MRI) for (1) likely diagnosis (enhancing/non-enhancing); (2) diagnostic confidence (5-point Likert scale); (3) need for additional imaging test (yes/no); and (4) need for follow-up imaging (yes/no). Diagnostic accuracy was compared using AUC; p value < 0.05 was considered significant. RESULTS: One hundred fifty-six lesions consisting of 18% enhancing (n = 28/156, mean size: 30.37 mm, range: 9.9-94 mm) and 82% non-enhancing (n = 128/156, mean size: 23.91 mm, range: 5.0-94.2 mm) were included. The confidence level was significantly lower for SECT than their MRI (4.50 vs. 4.80, p value < 0.05) but not significantly different for DECT and the corresponding MRI (4.78 vs. 4.78, p > 0.05). There were significantly more requests for additional imaging in the SECT session than the corresponding MRI (20% vs. 4%), which was not significantly different between DECT and their MRI counterpart session (5.7% vs. 4.9%). Inter-reader agreement was almost perfect for DECT and MRI (kappa: 0.8-1) and substantial in SECT sessions (kappa: 0.6-0.8) with comparable diagnostic accuracy between SECT, DECT, and MRI (p value > 0.05). CONCLUSION: Single-phase DECT allows confident and reproducible characterization of renal masses with fewer recommendation for additional and follow-up imaging tests than dual-phase SECT and a performance similar to MRI. KEY POINTS: • DECT utilization leads to similar additional image requests to MRI (5.7% vs. 4.9%, p value > 0.05), whereas single-energy CT utilization leads to significantly higher image requests (20% vs. 4%, p value < 0.05). • DECT and MRI utilization bring highly reproducible results with almost perfect inter-reader agreement (kappa: 0.8-1), better than the inter-reader agreement in SECT utilization (kappa: 0.6-0.8). • Readers' confidence was not significantly altered between DECT and their MRI readout session (p value > 0.05). In contrast, confidence in the diagnosis was significantly lower in the SECT session than their MRI readout (p value < 0.05).

Low keV portal venous phase as a surrogate for pancreatic phase in a pancreatic protocol dual-energy CT: feasibility, image quality, and lesion conspicuity.

OBJECTIVE: To assess the feasibility of a proposed pancreatic protocol CT generated from portal-venous phase (PVP) dual-energy CT (DECT) acquisition and its impact on image quality, lesion conspicuity, and arterial visualization/involvement. METHODS: We included 111 patients (mean age, 66.8 years) who underwent pancreatic protocol DECT (pancreatic phase, PP, and PVP). The original DECT acquisition was used to create two data sets-standard protocol (50 keV PP/65 keV PVP) and proposed protocol (40 keV/65 keV PVP). Three reviewers evaluated the two data sets for image quality, lesion conspicuity, and arterial visualization/involvement using a 5-point scale. The signal-to-noise ratio (SNR) of pancreas and lesion-to-pancreas contrast-to-noise ratio (CNR) was calculated. Qualitative scores, quantitative parameters, and dose-length product (DLP) were compared between standard and proposed protocols. RESULTS: The image quality, SNR of pancreas, and lesion-to-pancreas CNR of the standard and proposed protocol were comparable (p = 0.11-1.00). Lesion conspicuity was comparable between the standard and proposed protocols for pancreatic ductal adenocarcinoma (p = 0.55) and pancreatic cysts (p = 0.28). The visualization of larger arteries and arterial involvement were comparable between the two protocols (p = 0.056-1.00) while the scores were higher for smaller vessels in the standard protocol (p < 0.0001-0.0015). DLP of the proposed protocol (670.4 mGy·cm) showed a projected 42% reduction than the standard protocol (1145.9 mGy·cm) (p < 0.0001). CONCLUSION: Pancreatic protocol CT generated from a single PVP DECT acquisition is feasible and could potentially be an alternative to the standard pancreatic protocol with PP and PVP. KEY POINTS: • The lesion conspicuity for focal pancreatic lesions was comparable between the proposed protocol and standard dual-phase pancreatic protocol CT. • Qualitative and quantitative image assessments were almost comparable between two protocols. • The radiation dose of a proposed protocol showed a projected 42% reduction from the conventional protocol.

Targeted deep sequencing revealed variants in cell-free DNA of hormone receptor-positive metastatic breast cancer patients.

Cell-free DNA (cfDNA) is described to mirror intratumoral heterogeneity and gives insight about clonal evolution for improved therapeutic decisions. We sequenced cfDNA of a hormone receptor-positive, HER2-negative metastatic breast cancer (MBC) cohort with a high coverage to examine the prevalence and relevance of any detected variant. cfDNA of 44 MBC patients was isolated, followed by library construction using a customized targeted DNA panel with integrated unique molecular indices analyzing AKT1, AR, BRCA1, BRCA2, EGFR, ERCC4, ERBB2, ERBB3, ESR1, FGFR1, KRAS, MUC16, PIK3CA, PIK3R1, PTEN, PTGFR, and TGFB1. CfDNA was sequenced on the NextSeq® 550 platform (Illumina) and variants were analyzed with Ingenuity Variant Analysis (QIAGEN). We evaluated cfDNA variants in 40 of the 44 hormone receptor-positive and HER2-negative patients with a high mean coverage of 22,000×, resulting in MUC16, BRCA2, ERBB3, and AR variant calling in > 90% of the patients. 47% of all AR variants were pathogenic and at least one pathogenic or likely pathogenic variant was detected in each patient. A specific BRCA1 variant and > 3.5 pathogenic variants significantly associated with a reduced survival after diagnosis of metastasis. Longitudinal monitoring revealed an increase of pathogenic and likely pathogenic PIK3CA and ESR1 variant allele frequency under everolimus and exemestane, 8 months before proof of therapy failure by visual staging in one exemplary case. The identification of new variants with high prevalence, prognostic value, and dynamics under treatment by deep sequencing of cfDNA might empower sensitive monitoring and personalized therapeutic decisions.

Abdominal Imaging Findings in COVID-19: Preliminary Observations.

Background Angiotensin-converting enzyme 2, a target of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), demonstrates its highest surface expression in the lung, small bowel, and vasculature, suggesting abdominal viscera may be susceptible to injury. Purpose To report abdominal imaging findings in patients with coronavirus disease 2019. Materials and Methods In this retrospective cross-sectional study, patients consecutively admitted to a single quaternary care center from March 27 to April 10, 2020, who tested positive for SARS-CoV-2 were included. Abdominal imaging studies performed in these patients were reviewed, and salient findings were recorded. Medical records were reviewed for clinical data. Univariable analysis and logistic regression were performed. Results A total of 412 patients (average age, 57 years; range, 18 to >90 years; 241 men, 171 women) were evaluated. A total of 224 abdominal imaging studies were performed (radiography, n = 137; US, n = 44; CT, n = 42; MRI, n = 1) in 134 patients (33%). Abdominal imaging was associated with age (odds ratio [OR], 1.03 per year of increase; P = .001) and intensive care unit (ICU) admission (OR, 17.3; P < .001). Bowel-wall abnormalities were seen on 31% of CT images (13 of 42) and were associated with ICU admission (OR, 15.5; P = .01). Bowel findings included pneumatosis or portal venous gas, seen on 20% of CT images obtained in patients in the ICU (four of 20). Surgical correlation (n = 4) revealed unusual yellow discoloration of the bowel (n = 3) and bowel infarction (n = 2). Pathologic findings revealed ischemic enteritis with patchy necrosis and fibrin thrombi in arterioles (n = 2). Right upper quadrant US examinations were mostly performed because of liver laboratory findings (87%, 32 of 37), and 54% (20 of 37) revealed a dilated sludge-filled gallbladder, suggestive of bile stasis. Patients with a cholecystostomy tube placed (n = 4) had negative bacterial cultures. Conclusion Bowel abnormalities and gallbladder bile stasis were common findings on abdominal images of patients with coronavirus disease 2019. Patients who underwent laparotomy often had ischemia, possibly due to small-vessel thrombosis. © RSNA, 2020.

Comparative Effectiveness of Interventions in Initial Management of Spontaneous Pneumothorax: A Systematic Review and a Bayesian Network Meta-analysis.

STUDY OBJECTIVE: The best initial strategy for nontension symptomatic spontaneous pneumothorax is unclear. We performed a systematic review and meta-analysis to identify the most efficacious, safe, and efficient initial intervention in adults with nontension spontaneous pneumothorax. METHODS: MEDLINE, Scopus, Web of Science, and ClinicalTrials.gov were searched from January 1950 through December 2019 (print and electronic publications). Randomized controlled trials evaluating needle aspiration, narrow-bore chest tube (<14 F) with or without Heimlich valve insertion, and large-bore chest tube (≥14 F) insertion in spontaneous pneumothorax were included. Network meta-analyses were performed with a Bayesian random-effects model. RESULTS: Twelve studies were included in this review (n=781 patients). Analyses of efficacy (n=12 trials) revealed no significant differences between the interventions studied: narrow- versus large-bore chest tubes, odds ratio (OR) 1.05 (95% credible interval [CrI] 0.38 to 2.87); large-bore chest tube versus needle aspiration, OR 1.25 (95% CrI 0.65 to 2.62); and narrow-bore chest tube versus needle aspiration, OR 1.32 (95% CrI 0.54 to 3.42). Analyses of safety (n=10 trials) revealed a significant difference between needle aspiration and large-bore chest tube interventions: OR 0.10 (95% CrI 0.03 to 0.40). No differences were observed in needle aspiration versus narrow-bore chest tube (OR 0.29 [95% CrI 0.05 to 1.82]), and narrow- versus large-bore chest tube comparisons (OR 0.35 [95% CrI 0.07 to 1.67]). Analyses of efficiency were not pursued because of variation in reporting the length of stay (n=12 trials). Narrow-bore chest tube (<14 F) had the highest likelihood of top ranking in terms of immediate success (surface under the cumulative ranking curve=64%). Needle aspiration had the highest likelihood of top ranking in terms of safety (surface under the cumulative ranking curve=95.8%). CONCLUSION: In the initial management of nontension spontaneous pneumothorax, the optimal strategy between the choices of a narrow-bore chest tube (<14 F, top ranked in efficacy) and needle aspiration (top ranked in safety) is unclear. Complications were more common in large-bore chest tube (≥14 F, including 14-F tube) insertions compared with needle aspiration.

Coordination chemistry and photoswitching of dinuclear macrocyclic cadmium-, nickel-, and zinc complexes containing azobenzene carboxylato co-ligands.

The synthesis of mixed-ligand complexes of the type [M2L(µ-L')]+, where L represents a 24-membered macrocyclic hexaaza-dithiophenolate ligand, L' is an azobenzene carboxylate co-ligand, and M = Cd(II), Ni(II) or Zn(II), is reported. A series of new complexes were synthesized, namely [M2L(µ-L')]+ (L' = azo-H, M = Cd (1), Ni (2); L' = azo-OH, M = Zn (3), Ni (4); L' = azo-NMe2, M = Zn (5), Cd (6), Ni (7); L' = azo-CO2Me, M = Cd (8), Ni (9)), and characterized by elemental analysis, electrospray ionization mass spectrometry (ESIMS), IR, UV-vis and NMR spectroscopy (for diamagnetic Zn and Cd complexes) and X-ray single crystal structure analysis. The crystal structures of 3' and 5-8 display an isostructural series of compounds with bridging azobenzene carboxylates in the trans form. The paramagnetic Ni complexes 2, 4 and 7 reveal a weak ferromagnetic exchange interaction with magnetic exchange coupling constant values between 21 and 23 cm-1 (H = -2JS1S2). Irradiation of 1 with λ = 365 nm reveals a photoisomerization of the co-ligand from the trans to the cis form.

Experience With Iterative Reconstruction Techniques for Abdominopelvic Computed Tomography in Morbidly and Super Obese Patients.

OBJECTIVE: The aim of this study was to investigate the diagnostic performance of abdominopelvic computed tomography (CT) images reconstructed using filtered back projection (FBP) and iterative reconstruction (IR) algorithms in morbidly and super obese patients. MATERIALS AND METHODS: One hundred eighty-seven abdominopelvic CT examinations in portal venous phase were performed between February 2015 and February 2016 in 182 patients (mean age = 52 years, mean body mass index = 45.5). One hundred fourteen of 187 examinations were reconstructed using IR and 73 examinations were processed using FBP. Patients were further stratified based on body mass index. Sixty CT scans were reviewed by a single reader for image quality, image noise, and artifacts. Objective noise and attenuation were also determined. Size-specific dose estimate and CT dose index volume were compared and statistically analyzed. RESULTS: A diagnostic interpretation was rendered for all 187 examinations. A single-reader review of 60 cases showed greater diagnostic acceptability for IR when compared with FBP (image quality = 4.2 and 3.8 [P = 0.035], noise = 1.5 and 1.6 [P = 0.692], artifact = 1.4 and 1.5 [P = 0.759], respectively). For all examinations, the IR group had lower objective image noise (IR = 9.3 and FBP = 14.3; P < 0.001) and higher contrast-to-noise ratio (IR = 17.2 and FBP = 11.7; P < 0.001) without increase in radiation dose (size-specific dose estimate [IR = 15.1, FBP = 16.5 mGy; P = 0.045] and CT dose index volume [IR = 17.6, FBP = 18 mGy; P = 0.62]). CONCLUSIONS: In morbidly and super obese patients, diagnostic quality images could be reliably generated with minimal artifacts and noise using newer generation scanners integrated with IR without increasing radiation dose.

Influence of Maximal or Submaximal Effort on the Load Distribution of the Hand Analyzed by Manugraphy.

PURPOSE: This study aims to investigate if the hands' load-distribution pattern differs during maximal and submaximal grip. METHODS: Fifty-four healthy subjects used the 200-mm Manugraphy cylinder to assess the load-distribution pattern of both hands. On 2 testing days, the subjects performed grip-force testing: 1 hand with maximal effort and the other with submaximal effort. Sides changed for the second testing day. The whole contact area of the hand was sectioned into 7 anatomical areas, and the percent contribution of each area, in relation to the total load applied, was calculated. Maximal and submaximal efforts were compared across the 7 areas in terms of load contributions. RESULTS: Comparing maximum effort of the left and right hand, the load distribution was very similar without statistically significant differences between the corresponding areas. Comparing the maximal and the submaximal effort for each hand, 4 (left) and 5 (right) of the 7 corresponding areas showed statistically significant differences. Comparing the right hand, performing with maximal effort, with the left hand, performing with submaximal effort, 5 areas varied significantly. With the right hand performing submaximal effort, all 7 anatomical areas were significantly different. CONCLUSIONS: The load distribution of a healthy hand is different when performing with submaximal effort compared with maximal effort. To analyze a hand's load-distribution pattern, the opposite hand can be used as a reference. CLINICAL RELEVANCE: The hand's load-distribution pattern may be a useful indication of submaximal effort during grip-force testing.

Material Separation Using Dual-Energy CT: Current and Emerging Applications.

Dual-energy (DE) computed tomography (CT) offers the opportunity to generate material-specific images on the basis of the atomic number Z and the unique mass attenuation coefficient of a particular material at different x-ray energies. Material-specific images provide qualitative and quantitative information about tissue composition and contrast media distribution. The most significant contribution of DE CT-based material characterization comes from the capability to assess iodine distribution through the creation of an image that exclusively shows iodine. These iodine-specific images increase tissue contrast and amplify subtle differences in attenuation between normal and abnormal tissues, improving lesion detection and characterization in the abdomen. In addition, DE CT enables computational removal of iodine influence from a CT image, generating virtual noncontrast images. Several additional materials, including calcium, fat, and uric acid, can be separated, permitting imaging assessment of metabolic imbalances, elemental deficiencies, and abnormal deposition of materials within tissues. The ability to obtain material-specific images from a single, contrast-enhanced CT acquisition can complement the anatomic knowledge with functional information, and may be used to reduce the radiation dose by decreasing the number of phases in a multiphasic CT examination. DE CT also enables generation of energy-specific and virtual monochromatic images. Clinical applications of DE CT leverage both material-specific images and virtual monochromatic images to expand the current role of CT and overcome several limitations of single-energy CT. (©)RSNA, 2016.

Role of percutaneous abscess drainage in the management of young patients with Crohn disease.

BACKGROUND: Intra-abdominal abscess is a common complication of Crohn disease in children. Prior studies, primarily in adults, have shown that percutaneous abscess drainage is a safe and effective treatment for this condition; however, the data regarding this procedure and indications in pediatric patients is limited. OBJECTIVE: Our aim was to determine the success rate of percutaneous abscess drainage for abscesses related to Crohn disease in pediatric patients with a focus on treatment endpoints that are relevant in the era of biological medical therapy. MATERIALS AND METHODS: We retrospectively reviewed 25 cases of patients ages ≤20 years with Crohn disease who underwent percutaneous abscess drainage. Technical success was defined as catheter placement within the abscess with reduction in abscess size on post-treatment imaging. Clinical success was defined as (1) no surgery within 1 year of drainage or (2) surgical resection following drainage with no residual abscess at surgery or on preoperative imaging. Multiple clinical parameters were analyzed for association with treatment success or failure. RESULTS: All cases were classified as technical successes. Nineteen cases were classified as clinical successes (76%), including 7 patients (28%) who required no surgery within 1 year of percutaneous drainage and 12 patients (48%) who had elective bowel resection within 1 year. There was a statistically significant association between resumption of immunosuppressive therapy within 8 weeks of drainage and both clinical success (P < 0.01) and avoidance of surgery after 1 year (P < 0.01). CONCLUSION: Percutaneous abscess drainage is an effective treatment for Crohn disease-related abscesses in pediatric patients. Early resumption of immunosuppressive therapy is statistically associated with both clinical success and avoidance of bowel resection, suggesting a role for percutaneous drainage in facilitating prompt initiation of medical therapy and preventing surgical bowel resection.

Spleen volume on CT and the effect of abdominal trauma.

The aim of this study is to determine the magnitude of change in spleen volume on CT in subjects sustaining blunt abdominal trauma without hemorrhage relative to patients without disease and how the spleen volumes are distributed. Sixty-seven subjects with blunt abdominal trauma and 101 control subjects were included in this retrospective single-center, IRB-approved, and HIPAA-compliant study. Patients with an injured spleen were excluded. Using a semiautomatic segmentation program, two readers computed spleen volumes from CT. Spleen volume distribution in male and female trauma and control cohorts were compared nonparametrically. Spleen volume plotted against height, weight, and age were analyzed by linear regression. The number of females and males are, respectively, 35 and 32 in trauma subjects and 69 and 32 among controls. Female trauma patients (49.6 years) were older than males (39.8 years) (p = 0.02). Distributions of spleen volume were not normal, skewed above their means, requiring a nonparametric comparison. Spleen volumes in trauma patients were smaller than those in controls with medians of 230 vs 294 mL in males(p < 0.006) and 163 vs 191 mL in females(p < 0.04). Spleen volume correlated positively with weight in females and with height in male controls, and negatively with age in male controls (p < 0.01). Variation in reproducibility and repeatability was acceptable at 1.5 and 4.9 %, respectively. Reader variation was 1.7 and 4.6 % for readers 1 and 2, respectively. The mean spleen volume in controls was 245 mL, the largest ever reported. Spleen volume decreases in response to blunt abdominal trauma. Spleen volumes are not normally distributed. Our population has the largest spleen volume reported in the literature, perhaps a consequence of the obesity epidemic.

The efficacy of open partial aponeurectomy for recurrent Dupuytren's contracture.

INTRODUCTION: To evaluate the efficacy of open partial aponeurectomy for recurrent Dupuytren's contracture. METHODS: Eighteen patients with recurrent Dupuytren's contracture of 22 fingers were retrospectively assessed with a mean follow-up time of 94 months (range: 70-114 months). Examination parameters included the determination of range of motion (ROM), grip strength, pain and subjective outcome (disabilities of the arm, shoulder and hand (DASH) questionnaire). SURGICAL TECHNIQUE: Dissection with special regard to former skin incision and expected wound defect. Modified incisions after Bruner (Mini-Bruner incisions) were facilitated. Dissection started at the palm. Fibrous tissue was resected proximally within the palm including vertical fibrotic septae. Direct preparation of the neurovascular bundles (NVB) was facilitated from proximal to distal. If the anatomy of the neurovascular structures became unclear around the natatory ligament preparation of the NVB at the distal end of the fibrous cord was performed. After complete preparation of a NVB, dissection was continued from medial to lateral until the other bundle was completely released. Transposition flaps and skin transplants were often used for sufficient wound closure. RESULTS: Recurrence rate was 36 % applying the definition of van Rijssen et al. Fifteen patients had a grip strength of 90 % or higher in comparison to the contralateral side. Ten patients had a pinch strength of 90 % or higher in comparison to the contralateral side. All patients except for one had pain reduction or none postoperatively. Fifteen patients had a DASH score of 15 or lower (range: 0-47). An unrelated ray amputation was suffered due to wound healing complications. CONCLUSIONS: Open partial aponeurectomy performed by a board certified hand surgeon proved to be safe. The postoperative functional outcome seemed to be related to the individual course of the disease.

Iterative Reconstruction Techniques in Abdominopelvic CT: Technical Concepts and Clinical Implementation.

OBJECTIVE: This article discusses the clinical challenge of low-radiation-dose examinations, the commonly used approaches for dose optimization, and their effect on image quality. We emphasize practical aspects of the different iterative reconstruction techniques, along with their benefits, pitfalls, and clinical implementation. CONCLUSION: The widespread use of CT has raised concerns about potential radiation risks, motivating diverse strategies to reduce the radiation dose associated with CT. CT manufacturers have developed alternative reconstruction algorithms intended to improve image quality on dose-optimized CT studies, mainly through noise and artifact reduction. Iterative reconstruction techniques take unique approaches to noise reduction and provide distinct strength levels or settings.

Body MR Imaging: Artifacts, k-Space, and Solutions.

Body magnetic resonance (MR) imaging is challenging because of the complex interaction of multiple factors, including motion arising from respiration and bowel peristalsis, susceptibility effects secondary to bowel gas, and the need to cover a large field of view. The combination of these factors makes body MR imaging more prone to artifacts, compared with imaging of other anatomic regions. Understanding the basic MR physics underlying artifacts is crucial to recognizing the trade-offs involved in mitigating artifacts and improving image quality. Artifacts can be classified into three main groups: (a) artifacts related to magnetic field imperfections, including the static magnetic field, the radiofrequency (RF) field, and gradient fields; (b) artifacts related to motion; and (c) artifacts arising from methods used to sample the MR signal. Static magnetic field homogeneity is essential for many MR techniques, such as fat saturation and balanced steady-state free precession. Susceptibility effects become more pronounced at higher field strengths and can be ameliorated by using spin-echo sequences when possible, increasing the receiver bandwidth, and aligning the phase-encoding gradient with the strongest susceptibility gradients, among other strategies. Nonuniformities in the RF transmit field, including dielectric effects, can be minimized by applying dielectric pads or imaging at lower field strength. Motion artifacts can be overcome through respiratory synchronization, alternative k-space sampling schemes, and parallel imaging. Aliasing and truncation artifacts derive from limitations in digital sampling of the MR signal and can be rectified by adjusting the sampling parameters. Understanding the causes of artifacts and their possible solutions will enable practitioners of body MR imaging to meet the challenges of novel pulse sequence design, parallel imaging, and increasing field strength.

Functionality after arthroscopic debridement of central triangular fibrocartilage tears with central perforations.

PURPOSE: To investigate functional and subjective outcome parameters after arthroscopic debridement of central articular disc lesions (Palmer type 2C) and to correlate these findings with ulna length. METHODS: Fifty patients (15 men; 35 women; mean age, 47 y) with Palmer type 2C lesions underwent arthroscopic debridement. Nine of these patients (3 men; 6 women; mean static ulnar variance, 2.4 mm; SD, 0.5 mm) later underwent ulnar shortening osteotomy because of persistent pain and had a mean follow-up of 36 months. Mean follow-up was 38 months for patients with debridement only (mean static ulnar variance, 0.5 mm; SD, 1.2 mm). Examination parameters included range of motion, grip and pinch strengths, pain (visual analog scale), and functional outcome scores (Modified Mayo Wrist score [MMWS] and Disabilities of the Arm, Shoulder, and Hand [DASH] questionnaire). RESULTS: Patients who had debridement only reached a DASH questionnaire score of 18 and an MMWS of 89 with significant pain reduction from 7.6 to 2.0 on the visual analog scale. Patients with additional ulnar shortening reached a DASH questionnaire score of 18 and an MMWS of 88, with significant pain reduction from 7.4 to 2.5. Neither surgical treatment compromised grip and pinch strength in comparison with the contralateral side. We identified 1.8 mm or more of positive ulnar variance as an indication for early ulnar shortening in the case of persistent ulnar-sided wrist pain after arthroscopic debridement. CONCLUSIONS: Arthroscopic debridement was a sufficient and reliable treatment option for the majority of patients with Palmer type 2C lesions. Because reliable predictors of the necessity for ulnar shortening are lacking, we recommend arthroscopic debridement as a first-line treatment for all triangular fibrocartilage 2C lesions, and, in the presence of persistent ulnar-sided wrist pain, ulnar shortening osteotomy after an interval of 6 months. Ulnar shortening proved to be sufficient and safe for these patients. Patients with persistent ulnar-sided wrist pain after debridement who had preoperative static positive ulnar variance of 1.8 mm or more may be treated by ulnar shortening earlier in order to spare them prolonged symptoms. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.