Ultrasound imaging artifacts: How to recognize them and how to avoid them

Echocardiography has become a critical tool in clinical cardiology in evaluating cardiac physiology and diagnosing cardiac disease states. However, imaging artifacts are commonly encountered and often lead to misdiagnoses of life‐threatening diseases, such as aortic dissection and ventricular thrombus. It is, thus, critical for clinicians to understand these artifacts to avoid these misdiagnoses and protect patients from undue intervention. Artifacts can be broken down into two categories: those from violation of ultrasound system assumptions and those from interference by external equipment and devices. This review article discusses the most commonly encountered artifacts by category, explains their physical mechanisms, elaborates on their most common presentations, and instructs clinicians on how to avoid their misinterpretation.     

Formation of adhesion after intraperitoneal application of TiMesh: experimental study on a rodent model

Background: After laparoscopic repair of an incisive hernia, intraperitoneal prosthetic mesh, as a foreign material, is a strong stimulus for the development of adhesion, which may be the cause of serious complications. This experimental study compared three different meshes and their ability to prevent the formation of adhesion and shrinkage.

Methods: Ninety rats were divided randomly into three groups: in Group 1 Proceed mesh was implanted, in Group 2 Ultrapro mesh was implanted, and in Group 3 TiMesh was implanted. Mesh samples were fixed as an intraabdominal mesh in the upper part of the abdomen. Ten animals from each group were sacrificed on days 7, 28 and 60 post-surgery. After opening the abdomen, the formation of adhesion was assessed according to the Surgical Membrane Study Group (SMSG) score, the percentage of shrinkage of the mesh was established and inflammatory reaction scored.

Results: The SMSG score for adhesion was statistically significantly higher on all the postoperative days in the Proceed and Ultrapro mesh groups than in the TiMesh group which caused milder inflammatory reaction on 60th day than others meshes. The size of the mesh after 7 days was statistically significantly smaller in the Proceed and Ultrapro groups than in the TiMesh group, but after 60 days it was statistically significantly larger than in the TiMesh group.

Conclusion: The least formation of adhesion was noted in the TiMesh group, in which the highest level of shrinkage was noticed after 28 and 60 days. TiMesh has advantages over the other meshes studied, but a larger size mesh may be recommended for intraperitoneal application.     

Take Charge,Get Cured: The development and user testing of a culturally targeted mHealth decision tool on HCV treatment initiation for methadone patients

Objective

This paper describes the development of a mobile health tool to facilitate Hepatitis C (HCV) treatment decision making in methadone patients.

Massive arm edema following arteriovenous dialysis shunt creation in a patient with ipsilateral permanent pacemaker

Asymptomatic subclavian vein occlusion following insertion of a permanent pacemaker (PPM) or implantable cardioverter-defibrillator (ICD) is not uncommon. We report a case of a dual-chamber PPM in a patient with an unrecognized left subclavian vein occlusion who developed massive left arm edema following ipsilateral implantation of an arteriovenous (AV) hemodialysis graft. We recommend that patients with pre-existing PPM or ICD leads who are in need of vascular access for hemodialysis should have the AV shunts placed in the contralateral arm. If this is unavoidable, then preoperative subclavian vein screening for patency should be mandatory, even in asymptomatic patients. Sonography is an appropriate initial test in such a situation.     

CD133 expression is not restricted to stem cells, and both CD133+ and CD133- metastatic colon cancer cells initiate tumors

Colon cancer stem cells are believed to originate from a rare population of putative CD133+ intestinal stem cells. Recent publications suggest that a small subset of colon cancer cells expresses CD133, and that only these CD133+ cancer cells are capable of tumor initiation. However, the precise contribution of CD133+ tumor-initiating cells in mediating colon cancer metastasis remains unknown. Therefore, to temporally and spatially track the expression of CD133 in adult mice and during tumorigenesis, we generated a knockin lacZ reporter mouse (CD133lacZ/+), in which the expression of lacZ is driven by the endogenous CD133 promoters. Using this model and immunostaining, we discovered that CD133 expression in colon is not restricted to stem cells; on the contrary, CD133 is ubiquitously expressed on differentiated colonic epithelium in both adult mice and humans. Using Il10-/-CD133lacZ mice, in which chronic inflammation in colon leads to adenocarcinomas, we demonstrated that CD133 is expressed on a full gamut of colonic tumor cells, which express epithelial cell adhesion molecule (EpCAM). Similarly, CD133 is widely expressed by human primary colon cancer epithelial cells, whereas the CD133- population is composed mostly of stromal and inflammatory cells. Conversely, CD133 expression does not identify the entire population of epithelial and tumor-initiating cells in human metastatic colon cancer. Indeed, both CD133+ and CD133- metastatic tumor subpopulations formed colonospheres in in vitro cultures and were capable of long-term tumorigenesis in a NOD/SCID serial xenotransplantation model. Moreover, metastatic CD133- cells form more aggressive tumors and express typical phenotypic markers of cancer-initiating cells, including CD44 (CD44+CD24-), whereas the CD133+ fraction is composed of CD44lowCD24+ cells. Collectively, our data suggest that CD133 expression is not restricted to intestinal stem or cancer-initiating cells, and during the metastatic transition, CD133+ tumor cells might give rise to the more aggressive CD133(- )subset, which is also capable of tumor initiation in NOD/SCID mice.     

Optimizing primary PCI beyond “door to intervention time”—are we there yet?

AimTo assess the effects of shortened door-to-intervention (DTI) time on appropriate clinical decisions regarding the four most critical and costly decisions during primary percutaneous coronary intervention (PCI): cath-lab activation (CLA), use of glycoprotein IIb/IIIa inhibitors (GPI), use of PCI, and deployment of drug-eluting stent (DES).BackgroundSTEMI PCI patients are frequently subject to decision making based on abbreviated medical encounter and limited medical information.MethodsClinical data were prospectively collected in a STEMI registry over 19 months. Retrospective chart reviews were conducted to determine the level of appropriateness of the above-mentioned decisions.ResultsBetween June 2006 and December 2007, 200 EKGs with suspected STEMI were transmitted; 88 (44%) resulted in CLA. Compared to prior year, DTI times decreased from 145.7 to 69.9 min (P=.00001). DTI was longer during nights and weekends (87.5 vs. 51.8 min, P=.001) and the initial 6 months of the registry (86.8 vs. 66.8 min, P=.07). Nineteen (21.6%) of the patients undergoing angiography did not require revascularization, 56 (63.6%) received GPIs, and 65 patients (73.8%) underwent at least one vessel PCI, and at least one DES was used in 39 patients (60% of PCI cohort).When assessed for appropriateness, CLA was appropriate in 81.8% of the time and rendered borderline or inappropriate in 5.7% and 12.5%, respectively. GPI use was appropriate in 66% of the patients but seemed borderline or inappropriate in 28.5% and 5.4%, respectively. PCI was appropriate in 90% of the lesions treated, and borderline or inappropriate in 7.1% and 2.9%, respectively. DES use was viewed appropriate in 38.4%, and borderline or inappropriate in 51% and 10.2% of the DES deployments, respectively.Conclusions(1) In view of expedited care, certain information required for decision-making process is either not available or ignored during primary PCI. (2) Appropriate use of resources in primary PCI needs to be better defined. (3) Measures of extracting patients' previous medical records and imaging studies along with in-lab immediate blood work and echocardiography and establishing new “time-out” protocols for STEMI patients may improve resource utilization and patient care and outcome.