Optimum fuzzy filters for phase‐contrast magnetic resonance imaging segmentation

Purpose

To develop and validate a multidimensional segmentation and filtering methodology for accurate blood flow velocity field reconstruction from phase‐contrast magnetic resonance imaging (PC MRI).

Materials and Methods

The proposed technique consists of two steps: (1) the boundary of the vessel is automatically segmented using the active contour approach; and (2) the noise embedded within the segmented vector field is selectively removed using a novel fuzzy adaptive vector median filtering (FAVMF) technique. This two‐step segmentation process was tested and validated on 111 synthetically generated PC MRI slices and on 10 patients with congenital heart disease.

Results

The active contour technique was effective for segmenting blood vessels having a sensitivity and specificity of 93.1% and 92.1% using manual segmentation as a reference standard. FAVMF was the superior technique in filtering out noise vectors, when compared with other commonly used filters in PC MRI (P < 0.05). The peak wall shear rate calculated from the PC MRI data (248 ± 39 sec^?1), was significantly decreased to (146 ± 26 sec^?1) after the filtering process.

Conclusion

The proposed two‐step segmentation and filtering methodology is more accurate compared to a single‐step segmentation process for post‐processing of PC MRI data. J. Magn. Reson. Imaging 2009;29:155–165. © 2008 Wiley‐Liss, Inc.

     

Spontaneous splenic rupture: A rare presentation of dengue fever

Spontaneous rupture of the spleen with hemoperitoneum is a very rare, but serious manifestation of dengue fever (DF). We report a case of a young female who was presented with atraumatic abdominal pain, hypovolemic shock, anemia, ascites and hepatosplenomegaly with a recent history of a febrile illness. Subsequent investigations proved the presence of hemoperitoneum with spontaneous splenic rupture with seropositivity for DF. Early diagnosis and conservative management in this case resulted in a favorable outcome.     

COVID-19 vaccination and myocarditis: A review of current literature

Vaccination for coronavirus disease 2019 (COVID-19) is a critical strategy in controlling the current pandemic of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). After widespread COVID-19 vaccine imple-mentation, isolated case reports about myocarditis as a potential adverse reaction started coming. As of November 12, 2021, Centers for Disease Control and Prevention (CDC) has reported 1793 cases of myocarditis or pericarditis among young people with age 12-29 years, most cases have been reported in the male adolescent age group after the second dose of mRNA COVID-19 vaccines. It is very important to monitor the safety standards and adverse reactions of vaccines to effectively implement the vaccination policies. The CDC and the United States Food and Drug Administration actively monitor vaccine-associated adverse reactions a well-known platform such as Vaccine Adverse Event Reporting System. CDC continues to recommend COVID-19 vaccines and booster doses for eligible individuals (age limit according to the type of vaccine) after careful consideration from risk-benefit assessment and favorable outcomes from vaccination. Mechanisms behind COVID-19 vaccine-induced myocarditis are not clear yet but several possibilities such as molecular mimicry between the spike protein of SARS-CoV-2 and self-antigens, immune response to mRNA, and activation of host immunological system, trigger of the pre-existing dysregulated immunological system have been documented in the literature. Overall, data suggests a good prognosis, especially in young patients. In this review article, we cover currently available data on COVID-19 vaccine-related myocarditis incidence, concerns, possible mechanisms of myocarditis, current treatment, and outcome trends, risk vs benefit assessment of COVID-19 vaccination in this current pandemic.     

The role of near-infrared angiography in the assessment of post-operative venous congestion in random pattern, pedicled island and free flaps.

Indocyanine green near-infrared-video angiography (ICG-NIR-VA) was recently introduced for measuring perfusion of skin flaps. The prognostic value of this method with regards to post-transfer manipulations of the flap, and subsequently, flap survival is not adequately documented in the literature. In this paper, we report our experience with the ICG-NIR-VA in the intraoperative evaluation and post-operative follow-up of nine flaps (2 large random pattern, 4 pedicled island and 3 free flaps) used in various reconstructive procedures. Two flaps (1 random pattern and 1 free flap) showed delayed intraoperative uptake in ICG-NIR-VA. In the post-operative phase, (days 1-3) six flaps (1 random pattern, 2 axial pattern and 3 free flaps) showed a delay both in the ICG-NIR-VA uptake, as well as clearance. However, a clinical correlate was observed only in 2 of the 6 flaps demonstrating this delay: general and partial venous congestion was seen in a distally based interosseous posterior flap and a free lateral arm flap respectively. Leeches were implemented only based on the clinical signs. In one distally based perforator flap, the decision on perfusion augmentation via microanastomosis was based on the intraoperative ICG-NIR-VA finding. All flaps showed uneventful healing. Based on our observations, the question arises, not whether the ICG-NIR-VA is sensitive for the prognosis of venous congestion, upon which the flap manipulation strategy might rest-but whether it is too sensitive. Further, prospective studies are necessary.     

Anatomic Recanalization of Hepatic Vein and Inferior Vena Cava versus Direct Intrahepatic Portosystemic Shunt Creation in Budd-Chiari Syndrome: Overall Outcome and Midterm Transplant-Free Survival

Purpose

To assess overall outcome and midterm transplant-free survival of patients with Budd-Chiari syndrome (BCS) undergoing radiologic interventions including anatomic recanalization of the hepatic vein (HV) and inferior vena cava (IVC) and direct intrahepatic portosystemic shunt (DIPS) creation, both as combined and as independent groups.

Safety and Efficacy of PD-1 Inhibitors Among HIV-Positive Patients With Non–Small Cell Lung Cancer

Introduction

Despite widespread administration of programmed death receptor 1 (PD-1) pathway inhibitors among individuals with NSCLC, little is known about the safety and activity of these agents among human immunodeficiency virus (HIV) – infected patients since this population has largely been excluded from immunotherapy clinical trials.

Tendon Disorders After Total Hip Arthroplasty: Evaluation and Management

Background

Most patients who undergo total hip arthroplasty are very satisfied with their outcomes. However, there is a small subset of patients who have persistent pain after surgery. The etiology of pain after total hip arthroplasty varies widely; however, tendon disorders are a major cause of debilitating pain that often go unrecognized.

A Behavioral Intervention to Reduce Excessive Gestational Weight Gain

Objectives Excessive gestational weight gain (GWG) is a key modifiable risk factor for negative maternal and child health. We examined the efficacy of a behavioral intervention in preventing excessive GWG. Methods 230 pregnant women (87.4 % Caucasian, mean age = 29.2 years; second parity) participated in the longitudinal Glowing study (clinicaltrial.gov #NCT01131117), which included six intervention sessions focused on GWG. To determine the efficacy of the intervention in comparison to usual care, participants were compared to a matched contemporary cohort group from the Arkansas Pregnancy Risk Assessment Monitoring Survey (PRAMS). Results Participants attended 98 % of intervention sessions. Mean GWG for the Glowing participants was 12.7 ± 2.7 kg for normal weight women, 12.4 ± 4.9 kg for overweight women, and 9.0 ± 4.2 kg for class 1 obese women. Mean GWG was significantly lower for normal weight and class 1 obese Glowing participants compared to the PRAMS respondents. Similarly, among those who gained excessively, normal weight and class 1 obese Glowing participants had a significantly smaller mean weight gain above the guidelines in comparison to PRAMS participants. There was no significant difference in the overall proportion of the Glowing participants and the proportion of matched PRAMS respondents who gained in excess of the Institute of Medicine GWG guidelines. Conclusions for Practice This behavioral intervention was well-accepted and attenuated GWG among normal weight and class 1 obese women, compared to matched participants. Nevertheless, a more intensive intervention may be necessary to help women achieve GWG within the Institute of Medicine’s guidelines.     

Establishing IR in Emerging Countries—A Skill Development Initiative

Integrating interventional radiology (IR) into clinical practice faces challenges in emerging countries in Asia and Africa. Overcoming them requires innovative solutions customized to local needs. After an in-depth gap analysis of these challenges, we began an organized skill development initiative in late 2015 offering radiologists and their supporting staff fully paid scholarships for IR training. Its concept, structure, and progress are reported here. This initiative covered 8 countries, IR specialists (n = 51), senior residents (n = 24), and 15 educational events (training institute [n = 3]; participating countries [n = 12]). This initiative is intended to develop a global network of trained personnel who can support IR programs in challenging locations of emerging countries.