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Vascular anomalies encompass a spectrum of tumors and malformations that can cause significant morbidity and mortality in children and adults. Use of the International Society for the Study of Vascular Anomalies (ISSVA) classification system is strongly recommended for consistency. Vascular anomalies can occur in isolation or in association with clinical syndromes that involve complex multifocal lesions affecting different organ systems. Thus, it is critical to be familiar with the differences and similarities among vascular anomalies to guide selection of the appropriate imaging studies and possible interventions. Syndromes associated with simple vascular malformations include hereditary hemorrhagic telangiectasia, blue rubber bleb nevus syndrome, Gorham-Stout disease, and primary lymphedema. Syndromes categorized as vascular malformations associated with other anomalies include Klippel-Trenaunay-Weber syndrome, Parkes Weber syndrome, Servelle-Martorell syndrome, Maffucci syndrome, macrocephaly-capillary malformation, CLOVES (

Hemorrhage is the main cause of preventable death in both military and civilian trauma, and many of these patients die from non-compressible torso injuries. Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a minimally invasive method used for hemodynamic control of the hemorrhaging patient and has been compared to resuscitative thoracotomy (RT) with cross clamping of the aorta. REBOA has received a great deal of attention in recent years for its applicability and promise in adult trauma and non-trauma settings, but its utility in children is mostly unknown. The purpose of this review article is to summarize and consolidate what is currently known about the use of REBOA in children. Some of the challenges in implementing REBOA in children include small vascular anatomy and lack of outcomes data. Although the evidence is limited, there are established instances in the literature of children and adolescents who have undergone endovascular occlusion of the aorta for hemorrhage control with positive outcomes and survival rates equivalent to their adult counterparts. There is a need for further formal evaluation of REBOA in pediatric patients with prospective studies to look at the safety, feasibility and efficacy of the technique. STUDY TYPE: Narrative Literature Review LEVEL OF EVIDENCE: IV.

Purpose To determine the diagnostic yield and safety of image-guided lung biopsies in immunocompromised pediatric patients. Materials and Methods This was a retrospective pediatric cohort study conducted from June 2000 to April 2017. Subjects were 0–17 years of age (median, 10 years of age). There were 46 males (48%). A total of 73 consecutive image-guided lung biopsies were performed in 68 patients (weight range, 4.9–97.3 kg [median, 25.3 kg]). The indication for biopsy was to isolate an organism to tailor medical therapy. All patients were immunocompromised with an underlying history of bone marrow transplantation (n = 50), primary immunodeficiency (n = 14), and solid organ transplantation (n = 4). Patient and technical factors were analyzed for rates of complication. Results Overall diagnostic yield was 43 of 73 patients (60%). There were 14 minor (19%) and 8 major (11%) complications. Major complications included pneumothorax or hemoptysis requiring intervention (n = 6), and death (n = 2). The histological diagnosis was an infectious cause in 5 of 8 major complications (63%). There were statistically significant differences between the rates of complications with the imaging modality used (P = .02) and the use of fine needle aspiration (P = .02). Conclusions Image-guided percutaneous lung biopsy can be helpful in isolating an organism to tailor therapy. Biopsies performed in immunosuppressed patients result in an elevated complication risk of up to 30% and demonstrate lower diagnostic yield and increased mortality, which should warrant detailed discussion with the primary team and family.

BACKGROUND Post-operative atrial fibrillation (POAF) is a common yet understudied clinical issue after coronary artery bypass graft (CABG) leading to higher mortality rates and stroke. This systematic review and meta-analysis evaluated the rates of adverse outcomes between patients with and without POAF in patients treated with CABG or combined procedures. METHODS The search period was from the beginning of PubMed and Embase to May 18th, 2020 with no language restrictions. The inclusion criteria were: (1) studies comparing new onset atrial fibrillation before or after revascularization vs. no new onset AF before or after revascularization. The outcomes assessed included all-cause mortality, cardiac death, cerebral vascular accident (CVA), myocardial infarction (MI), repeated revascularization, major adverse cardiac event (MACE), and major adverse cardiac and cerebrovascular events (MACCEs). RESULTS Of the 7,279 entries screened, 11 studies comprising of 57,384 patients were included. Compared to non-POAF, POAF was significantly associated with higher risk of all-cause mortality (Risk Ratio (RR) = 1.58; 95% Confidence Interval (CI): 1.42−1.76, P < 0.00001) with accompanying high level of heterogeneity ( I2 = 62%). Conclusions Patients with POAF after CABG or combined procedures are at an increased risk of all-cause mortality or CVAs. Therefore, POAF after such procedures should be closely monitored and treated judiciously to minimize risk of further complications. While there are studies on POAF versus no POAF on outcomes, the heterogeneity suggests that further studies are needed.

Background: There is a bidirectional relationship between blood pressure variability (BPV) and anxiety, but few studies have examined the gender- and age-specific effects of visit-to-visit BPV on incident anxiety. We examined the predictive value of BPV for the incidence of anxiety in a family clinic cohort.Methods: Consecutive patients with a first attendance to family medicine clinics in Hong Kong between January 1, 2000, and December 31, 2002, with at least three blood pressure measurements available thereafter were included. The primary endpoint was incident anxiety as identified by ICD-9 coding.Results: This study included 48,023 (50% males) patients with a median follow-up of 224 [interquartile range (IQR): 217–229] months. Females were more likely to develop incident anxiety compared to males (incidence rate: 7 vs. 2%), as were patients of older age. Significant univariate predictors were female gender, older age, preexisting cardiovascular diseases, respiratory diseases, diabetes mellitus, hypertension, and gastrointestinal diseases, various laboratory examinations, and the number of blood pressure measurements. Higher baseline, maximum, minimum, standard deviation (SD), coefficient of variation (CV), and variability score of diastolic blood pressure significantly predicted incident anxiety, as did all systolic blood pressure measures [baseline, latest, maximum, minimum, mean, median, variance, SD, root mean square (RMS), CV, and variability score].Conclusions: The relationships between longer-term visit-to-visit BPV and incident anxiety were identified. Female and older patients with higher blood pressure and higher BPV were at the highest risks of incident anxiety.

Purpose To evaluate technical and clinical success and report long-term outcomes of portal vein (PV) recanalization in pediatric orthotopic liver transplant (OLT) patients with chronic PV occlusion. Materials and Methods This is a retrospective review of 15 OLT patients (5 males) with chronic PV occlusion who underwent PV recanalization (33 procedures) between October 2011 and February 2018. Median age was 4.5 years (range, 1–16 years); median weight was 16.6 kg (range, 11.5–57.3 kg). Median time interval from OLT to first intervention was 3.25 years (range, 0.6–15.7 years). Clinical presentations included hypersplenism (n = 12), gastrointestinal bleeding (n = 9), and ascites (n = 3). One patient had incidental diagnosis of PV occlusion. Primary, primary-assisted, and secondary patency at 3, 6, 12, and 24 months were evaluated. Results Technically successful PV recanalization and reduction of PV pressure gradient to ≤ 5 mm Hg was performed in 13/15 patients (87%). Ten of 15 (67%) patients had successful recanalization with the first attempt. Clinical success, defined as improvement in signs and symptoms of portal hypertension, was achieved in 12/13 (92%) patients. Five of 33 (15%) major complications (Society of Interventional Radiology class C), including perisplenic hematoma (n = 2), hemoperitoneum (n = 2), and hepatic artery pseudo aneurysm (n = 1), were managed with pain medication and blood product replacement. Median follow-up was 22 months (range, 1–77 months). Median primary patency was 5 months. Primary patency at 3, 6, 12, and 24 months was 53.8%, 46.2%, 38.5%, and 30.8%, respectively. Primary-assisted patency was 84.6%, 76.9%, 53.8%, and 46.2%, respectively. Secondary patency was 92.3%, 84.6%, 53.8%, and 46.2%, respectively. Conclusions PV recanalization is a safe and effective minimally invasive option in the management of chronic PV occlusion after pediatric OLT.

BACKGROUND: Implementation science (IS) and quality improvement (QI) inhabit distinct areas of scholarly literature, but are often blended in practice. Because practice-based research networks (PBRNs) draw from both traditions, their experience could inform opportunities for strategic IS-QI alignment. OBJECTIVE: To systematically examine IS, QI, and IS/QI projects conducted within a PBRN over time to identify similarities, differences, and synergies. DESIGN: Longitudinal, comparative case study of projects conducted in the Oregon Rural Practice-based Research Network (ORPRN) from January 2007 to January 2019. APPROACH: We reviewed documents and conducted staff interviews. We classified projects as IS, QI, IS/QI, or other using established criteria. We abstracted project details (e.g., objective, setting, theoretical framework) and used qualitative synthesis to compare projects by classification and to identify the contributions of IS and QI within the same project. KEY RESULTS: Almost 30% (26/99) of ORPRN’s projects included IS or QI elements; 54% (14/26) were classified as IS/QI. All 26 projects used an evidence-based intervention and shared many similarities in relation to objective and setting. Over half of the IS and IS/QI projects used randomized designs and theoretical frameworks, while no QI projects did. Projects displayed an upward trend in complexity over time. Project used a similar number of practice change strategies; however, projects classified as IS predominantly employed education/training while all IS/QI and most QI projects used practice facilitation. Projects including IS/QI elements demonstrated the following contributions: QI provides the mechanism by which the principles of IS are operationalized in order to support local practice change and IS in turn provides theories to inform implementation and evaluation to produce generalizable knowledge. CONCLUSIONS: Our review of projects conducted over a 12-year period in one PBRN demonstrates key synergies for IS and QI. Strategic alignment of IS/QI within projects may help improve care quality and bridge the research-practice gap. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11606-021-06610-1.

Spinal muscular atrophy (SMA) is an autosomal-recessive disease affecting motor neurons and is the most common genetic cause of death in infants. Intrathecal nusinersen is the only therapy approved by the U.S. Food and Drug Administration for SMA. Deformities and spinal instrumentation from orthopedic surgeries are common in children with SMA, complicating traditional intrathecal access for nusinersen delivery. Cervical punctures are routinely performed in adults for cervical myelograms and should be considered for children with SMA as a viable form of intrathecal access. This retrospective study assessed technical feasibility and complications of ultrasound-guided cervical puncture for nusinersen administration. We reviewed 14 consecutive ultrasound-guided cervical punctures for nusinersen administration with local anesthesia. We reviewed technical success and complications. All procedures were technically successful. There were no major complications. Two minor complications included headaches that resolved by observation within 24 h after the procedure. Our series describes a successful novel method of ultrasound-guided cervical spine access for intrathecal administration of nusinersen, adding to the armamentarium of procedures for delivering nusinersen to adolescents with challenging lumbar spine access caused by scoliosis and spinal instrumentation. This technique has the advantages of real-time ultrasound guidance and potential avoidance of general anesthesia in children.

Phosphatase and tensin homolog (PTEN) hamartoma tumor syndrome (PHTS) is characterized by formation of recurrent benign tumors described as PTEN hamartoma of soft tissue that may contain fast flow vascular anomalies (FFVA). The purpose of this study is to review the temporal evolution and management of FFVA in PHTS. A retrospective review of 22 patients (9 males), age 1 to 18 (median 9) years diagnosed with PHTS at a tertiary care pediatric hospital between October 2002 and August 2017 revealed 4 patients with FFVA. Imaging, management, and treatment complications were reviewed. During median follow-up of 8 (range: 4–13) years, ultrasound and magnetic resonance imaging performed for recurrent pain, showed progressive increase in the size of hamartomas and development of new FFVA in three-fourth patients. Medical management included pain medications, oral sirolimus, and physical and psychiatric therapy. Surgical excision of hamartoma (n = 1) resulted in recurrence within 3 months. Between 4 and 24 (average 1.5/year) embolizations were performed per patient. Pain related to FFVA responded well to embolization. Pain secondary to PTEN hamartoma responded poorly to percutaneous sclerosant injection, but demonstrated improvement with sirolimus. There was no correlation between serum sirolimus levels and frequency/timing of recurrence of FFVA/hamartoma. Complications included sclerosant migration into digital arteries (n = 1), subclavian vein stenosis due to glue migration (n = 1), oral mucositis (n = 4), and elevated triglycerides (n = 4). Patients with PHTS present with recurrent pain requiring life-long management with a multi-disciplinary team. Pain due to FFVA responds to embolization, and pain due to hamartoma responds to sirolimus. This improves quality of life, but does not prevent disease progression.

Femoral tunneled central line placement in the pediatric population offers an alternative means for intravenous (IV) access, but there is concern for higher complication and infection rates when placed at bedside. To describe the complications and infection outcomes of primary femoral tunneled central venous catheter placement in the interventional radiology suite compared to the portable bedside location at a single tertiary pediatric institution. We conducted a retrospective review comparing interventional radiology suites vs. bedside primary tunneled common femoral vein central line placement (January 2014 to December 2015). We identified 244 primary femoral placements in pediatric patients, ages 1 day to 18 years, using our electronic medical record and collected into a Research Electronic Data Capture. We compared categorical variables using the Fisher exact test. We compared continuous variables using the Wilcoxon rank test. In total, 2,375 pediatric patients received peripherally inserted and central lines; 244 of these were primary femoral tunneled central venous catheters (in 140 boys and 104 girls). In 140 children (mean age: 206 days), lines were inserted in the interventional radiology (IR) suite (technical success of 100%), with 14 (10.0%) complications including infection (n=7), malposition (n=2), bleeding (n=0), thrombosis (n=1) and line occlusion (n=4). The infection rate was 2.1 per 1,000 line days. In 104 children (mean age: 231 days), lines were placed at bedside (technical success 100%) with 14 (13.3%) complications including infection (n=3), malposition (n=5), bleeding (n=0), thrombosis (n=2) and line occlusion (n=4). The infection rate was 0.78 per 1,000 line days. The total line days were 7,109, of which 3,258 were in the IR suite and 3,851 in the bedside group. There was no statistical significance for complication rate (P=0.55) or infection rate (P=0.57) between bedside and interventional suite placements. In a cohort of children receiving primary femoral tunneled central venous catheters, the complication and infection rates in a bedside setting are not significantly increased compared to the lines placed in an IR suite. The perception of increased infection and complications from bedside-placed tunneled central venous catheters appears to be hyperbolized.

We present a case of a 77-year-old woman who sustained blunt ocular trauma leading to a scleral rupture, superonasal subconjunctival crystalline lens dislocation, iris loss, and hyphema. Computed tomography aided in the diagnosis of traumatic phacocele. Surgical exploration revealed an 11.0 mm anterior scleral rupture that was then repaired. Secondary implantation of the uniquely designed tripodal anterior chamber intraocular lens (AC IOL) was the choice because of the presence of extensive iris loss, scleral rupture, cornea edema, and hyphema at the primary setting. This case demonstrates successful restoration of globe integrity and a good visual outcome from an appropriate AC IOL selection and timing of IOL implantation.

Objective Compare the cost of placing tunneled femoral central lines in the interventional radiology suite to portable bedside placement using time-driven activity-based costing. Methods Detailed process maps were created using information generated from interviews with frontline staff, direct shadowing of patient procedures (19 patients—8 in-suite, 11 portable; patient age 4 days to 37 months; 6 males, 13 females), and electronic medical record review (80 patients—44 in-suite, 36 portable; patient age 1 day to 20 months; 42 males, 38 females) who underwent a tunneled femoral central line placement at a tertiary care pediatric hospital from January 1, 2018, to June 30, 2018. Procedures were conducted in-suite using fluoroscopy guidance or portably at the patient’s bedside using ultrasound. Capacity cost rates for each resource in the process maps were calculated for personnel, equipment, facilities, and supply costs. Costs for each process step were then calculated by multiplying the capacity cost rate by the mean duration of each step. Stepwise costs were summed for the entire process to generate a cost for each tunneled femoral central line placement pathway. Results Total pathway time for tunneled femoral central lines placement in-suite was 123 to 134 min (nonsedated) and 120 to 131 min (sedated) for a cost of $923 to $990 and $1,262 to $1,386, respectively. Total pathway time for tunneled femoral central lines placed portably were 117 to 119 min (nonsedated) and 115 to 147 min (sedated) for a cost of $1,060 to $1,066 and $1,379 to $1,393, respectively. Conclusion Total costs of tunneled femoral central lines placed in-suite were similar to total costs for lines placed portably. Cost should not be a primary consideration when deciding upon tunneled femoral central line approach in these patients.

Pediatric lymphatic malformations (LMs) represent a rare, benign subtype of vascular malformations that can commonly occur in the head or neck region, specifically in or around the orbit. Orbital LMs typically require a multidisciplinary team of specialists and diagnostic imaging. Historically, treatment options for these periorbital LMs include imaging-guided drainage with sclerotherapy in addition to surgery, at times in conjunction with medical management. There exists debate in terms of an approach for management timing of these lesions across various treatment centers, and interventional radiologists should be informed regarding treatment timing considerations in evaluating patients for potential intervention. The aim of this case series is to review the current standards regarding therapeutic interventions for LMs in the literature and discuss an organized approach to guide the optimal treatment timing for the management of these lesions. In this case series, two pediatric patients – one 2 years old and one 12 years old – presented with a unilateral periorbital LM and received treatment at an academic tertiary care children’s hospital. The first patient was diagnosed with macrocystic periorbital LM after presenting with eye pain and eyelid swelling. After initial ultrasound-guided drainage to relieve eye pressure, the patient rebled into the LM and underwent sclerotherapy intervention. The second case involved a periorbital LM with intralesional hemorrhage presenting as a violaceous eyelid mass diagnosed after bumping into a swing. The patient was treated medically with interval growth of the LM and underwent subsequent sclerotherapy. Both patients responded well to ultrasound-guided sclerotherapy. The management timing and decision to intervene were based on consults from multidisciplinary services, age, risk factors, and clinical stability on presentation. We present two cases of pediatric periorbital LM and review an organized institutional approach for treatment timing based on paradigms in the literature.

Objective To review the technical aspects and categorize the imaging findings of dynamic contrast enhanced magnetic resonance lymphangiography (DCMRL) and correlate the findings with patient management options. Materials and methods A retrospective review of patients who underwent DCMRL between June 2012 and August 2017 at a tertiary care paediatric hospital was performed. Twenty-five DCMRL studies were performed in 23 patients (9 males, 13 females, 1 ambiguous gender) with a median age of 4 years (range: 1 month–29 years). DCMRL imaging findings were reviewed, categorized and the impact on patient management was studied. Results DCMRL was technically successful in 23/25 (92%) studies. DCMRL findings were categorized based on the status of central conducting lymphatics (CCL) and alternate lymphatic pathways as follows: Type 1 – normal CCL with no alternate lymphatic pathways, Type 2 – partial (2a) or complete (2b) non-visualization of CCL with reflux of contrast into alternate pathways and Type 3 – normal CCL with additional filling of alternate pathways. Type 1 DCMRL patients (n = 5) were reassured and conservative management was continued, Type 2 patients (n = 10) had evidence of CCL obstruction hence thoracic duct ligation or embolization was avoided and other options such as lymphatic fluid diversion using Denver® shunt or lympho-venous anastomosis were used, and Type 3 patients (n = 8) were evaluated for elevated central venous pressure as a cause of lymphatic backflow in addition to Denver® shunt, lympho-venous anastomosis, thoracic duct ligation or embolization. Conclusion DCMRL is an evolving imaging technique for understanding abnormalities of the central conducting lymphatics. Categorization of imaging findings may be helpful in guiding selection of management options.

Pentraxin-3 (PTX-3) is a multi-functional pattern recognition molecule produced by various cell types of peripheral tissues in different infections. It is raised in sepsis, but its values in predicting disease severity or mortality outcomes have been controversial. Therefore, we conducted a systematic review and meta-analysis of these associations.PubMed and Embase were searched until July 18, 2017 for studies that evaluated the relationship between PTX-3 levels and disease severity or mortality in sepsis.A total of 23 and 10 entries were retrieved from both databases, respectively, of which 16 studies were included in the final meta-analysis. A total of 3001 patients (56% male, mean age 63 ± 15 years; mean follow-up duration of 207 days) were analysed. PTX-3 was significantly higher in patients with more severe sepsis compared to those with less severe sepsis (standard mean difference = 18.5 ng/mL, standard error: 4.5 ng/mL, P 0.0001) and higher in non-survivors compared to survivors (standard mean difference = 40.3 ng/mL, standard error: 6.8 ng/mL, P 0.0001). Elevated PTX-3 levels significantly increased the risk of all-cause mortality (hazard ratio: 1.91, 95% CI: 1.53 to 2.46, P 0.0001).PTX-3 significantly predicts disease severity and mortality in sepsis.

Although cardiovascular risk factor levels are substantially different in Caucasians, African-American, Hispanics, and Asians, the relative rates of coronary heart disease in these groups are not consistent with these differences. The objective of the study is to assess the differences in the prevalence and severity of coronary artery calcification, as a measure of atherosclerosis, in these different ethnic groups.Electron-beam tomography was performed in 16,560 asymptomatic men and women (Asians=1336, African-Americans=610, Hispanics=1256) agedor=35 years referred by their physician for cardiovascular risk evaluation. The study population encompassed 70% males, aged 52+/-8 years.Caucasians were more likely to present with dyslipidemia (p0.0001), while African-Americans and Hispanics had a higher prevalence of smoking, diabetes, and hypertension (all p0.001). After adjustment for age, gender, risk factors, and treatment for hypercholesterolemia, compared with Caucasians, the relative risks for men having coronary calcification were 0.64 (95% CI: 0.48-0.86) in African-Americans, 0.88 (95% CI: 0.67-1.15) in Hispanics, and 0.66 (95% CI: 0.55-0.80) in Asians. After similar adjustments, the relative risks for women having coronary calcification, were 1.58 (95% CI: 1.13-2.19) for African-Americans, 0.84 (95% CI: 0.66-1.06) in Hispanics, and 0.71 (95% CI: 0.56-0.89) in Asian women. After adjusting for age and risk factors using multivariable analysis, African-American men were least likely to have any coronary calcium while African-American women had significantly higher OR of any calcification. Asian men and women had significantly lower OR of any calcification. There was no significant difference in prevalence or severity of atherosclerosis between Hispanics and Caucasians, in men or women.Our study results demonstrate significant difference in the presence as well as severity of calcification according to ethnicity, independent of atherosclerotic risk factors. Results from this study (physician referred) closely parallel the results from MESA (population based, measured risk factors). Ethnic specific data on the predictive value of differing coronary calcium scores are needed.

UNLABELLED The detection of coronary artery calcification (CAC) using the electron beam tomography (EBT) scanner provides a noninvasive indicator for coronary artery disease (CAD). Physicians interested in preventative medicine also are using this modality to track atherosclerosis over time. Two new iterations of the EBT scanner have been introduced. We sought to evaluate the image quality of each machine to examine whether patients scanned on a previous model would have similar image quality and results to those scanned on the newest scanner. METHODS This study used the C-150 XP, C300, and the e-Speed EBT scanners in high-resolution volume mode. A cork chest phantom was constructed for use as a human chest. A mixture of calcium phosphate, cornstarch and glue was placed inside the wells to simulate coronary calcium. The foci masses were 3, 5, 7, 10, 15, 20, 40, 60, 80, 100, and 200 mg (calcium mass), which provided the 55 foci of different masses and densities to simulate coronary calcium in the chest phantom. Each phantom was scanned multiple times, using both 1.5- and 3-mm slice thickness and table collimation settings with each scanner. RESULTS There were no statistical differences found between the 1.5-mm and 3.0-mm slice thickness calcium foci scores (Agatston & volumetric) for all 3 EBT scanners. The C-150 XP scanner had a variability of 6.01% between 1.5-mm and 3.0-mm slice thickness. Analysis by t test revealed that the mean noise value of C-150 XP was significantly higher than the C300, e-Speed (50 milliseconds), and e-Speed (100 milliseconds) with P values of 0.001, 0.025, and 0.001, respectively. Comparison of 1.5-mm versus 3.0-mm slice thickness noise value showed a significant difference only for the C-150 XP scanner (P < 0.05). CONCLUSIONS The use of the 3 EBT scanners in longitudinal studies of patients coronary calcium score is feasible to obtain similar calcium score values. The C-150 XP has the greatest noise effect in comparison to the C300 and e-Speed scanners. Improved image noise should improve reproducibility of the calcium measurement with these newer devices.

Electron beam angiography is a minimally invasive imaging technique. Adequate vascular opacification throughout the study remains a critical issue for image quality. We hypothesized that vascular image opacification and uniformity of vascular enhancement between slices can be improved using multiphase contrast medium injection protocols.We enrolled 244 consecutive patients who were randomized to three different injection protocols: single-phase contrast medium injection (Group 1), dual-phase contrast medium injection with each phase at a different injection rate (Group 2), and a three-phase injection with two phases of contrast medium injection followed by a saline injection phase (Group 3). Parameters measured were aortic opacification based on Hounsfield units and uniformity of aortic enhancement at predetermined slices (locations from top [level 1] to base [level 60]).In Group 1, contrast opacification differed across seven predetermined locations (scan levels: 1st versus 60th, P.05), demonstrating significant nonuniformity. In Group 2, there was more uniform vascular enhancement, with no significant differences between the first 50 slices (P.05). In Group 3, there was greater uniformity of vascular enhancement and higher mean Hounsfield units value across all 60 images, from the aortic root to the base of the heart (P.05).The three-phase injection protocol improved vascular opacification at the base of the heart, as well as uniformity of arterial enhancement throughout the study.

To evaluate the effect of scanner collimation on the ability to detect small cardiac vessels using electron beam CT coronary angiography (EBA).EBA scans from 40 patients who underwent study on two separate occasions with 3 mm (initial scan) and 1.5 mm (follow-up scan) collimation protocols were analyzed. Vessels of2 mm in diameter were identified.The 1.5 mm collimation allowed 3-D visualization of 129 vessels2 mm in diameter, while 3 mm collimation only allowed visualization of 89 vessels (p0.001). The right coronary artery branches and distal LAD segments though were not displayed satisfactorily in almost half of the 3-D studies with either protocol.There was significant improvement in detection of small cardiac vessels with a 1.5 mm collimation EBA protocol compared to a 3 mm protocol. Both protocols though were insufficient for reliable visualization of the right coronary artery branches and distal LAD segments.

Rationale and objective The newest generation of electron beam tomographic scanner (e-Speed) has increased spatial and temporal resolution compared with the C-150 XP scanner. The aim of this study was to evaluate coronary artery calcium screening image quality between the e-Speed and C-150 scanners (GE Imatron, San Francisco, CA). Materials and methods Studies from 41 patients (14 women and 27 men) who underwent serial coronary artery calcium screening with the C-150 (first study) and the e-Speed (second study) were analyzed. Individual computed tomography (CT) slices were assessed for coronary artery motion artifacts, and CT Hounsfield units (HU) and noise values (CT HU standard deviation) at 16 discrete cardiac sites were measured and averaged. Results With the e-Speed scanner, there were significant decreases in right coronary artery motion artifacts compared with the C-150 scanner (0.3% versus 1.8%, P < .001) as well as decreased noise values (24.3 versus 32.0 HU, P < .001). Conclusion Image quality is significantly improved with use of the e-Speed scanner, due to its improved temporal and spatial resolution, compared with the C-150 scanner.

The synthesis, characterization and catalytic activity of zirconium complexes containing bulky pentaarylcyclopentadienyl ligands are reported. The monocyclopentadienyl 12-electron complex, trichloropentaphenylcyclopentadienylzirconium(IV), C5Ph5ZrCl3 (I), has an unusual monomeric structure in the solid state and has short Zr–ligand distances suggesting that the complex has significant Lewis acidity. The phenyl rings adopt a propeller arrangement in the solid state; VT 1H-NMR measurements of the analogous trichloro(tetraphenyl-m-tolylcyclopentadienyl)zirconium(IV) (II) indicate that there is rapid rotational motion of the phenyl rings. The Lewis acidity of this complex is manifested in its ability to catalyze the [4+2] cycloadditions of acrolein and methyl acrylate to cyclopentadiene. The sandwich complex, C5Ph5CpZrCl2 (III), has more typical Zr–ligand distances, but has a more parallel arrangement of the two cyclopentadienyl rings and does not display the reactivity shown by I and II.

Computed tomographic angiography can visualize detailsof left atrial structure relevant for atrial fibrillation (AF) abla-tion. In this example from a patient with a history of paroxys-mal AF referred for pre-ablation assessment of pulmonaryveins, three-dimensional images define pulmonary vein loca-tions and demonstrate an additional small pulmonary veinnear the right lower pulmonary vein (Fig. 1). Endocardial im-ages provide anatomic detail of the spatial relationships be-tween the ostia of the pulmonary veins (Fig. 2). These imagessupplement and enhance the understanding of two-dimension-al images, providing a more comprehensive analysis of atrialstructure for left atrial ablation procedures. Reference

The newest generation of electron beam tomographic scanner (e-Speed) has increased spatial and temporal resolution compared with the C-150 XP scanner. The aim of this study was to evaluate coronary artery calcium screening image quality between the e-Speed and C-150 scanners (GE Imatron, San Francisco, CA).Studies from 41 patients (14 women and 27 men) who underwent serial coronary artery calcium screening with the C-150 (first study) and the e-Speed (second study) were analyzed. Individual computed tomography (CT) slices were assessed for coronary artery motion artifacts, and CT Hounsfield units (HU) and noise values (CT HU standard deviation) at 16 discrete cardiac sites were measured and averaged.With the e-Speed scanner, there were significant decreases in right coronary artery motion artifacts compared with the C-150 scanner (0.3% versus 1.8%, P.001) as well as decreased noise values (24.3 versus 32.0 HU, P.001).Image quality is significantly improved with use of the e-Speed scanner, due to its improved temporal and spatial resolution, compared with the C-150 scanner.