Research Spotlight

Posted May 15th 2019

State of the art: utility of multi-energy CT in the evaluation of pulmonary vasculature.

Alastair Moore, M.D.

Alastair Moore, M.D.

Rajiah, P., Y. Tanabe, S. Partovi and A. Moore (2019). “State of the art: utility of multi-energy CT in the evaluation of pulmonary vasculature.” Int J Cardiovasc Imaging May 2. [Epub ahead of print].

Full text of this article.

Multi-energy computed tomography (MECT) refers to acquisition of CT data at multiple energy levels (typically two levels) using different technologies such as dual-source, dual-layer and rapid tube voltage switching. In addition to conventional/routine diagnostic images, MECT provides additional image sets including iodine maps, virtual non-contrast images, and virtual monoenergetic images. These image sets provide tissue/material characterization beyond what is possible with conventional CT. MECT provides invaluable additional information in the evaluation of pulmonary vasculature, primarily by the assessment of pulmonary perfusion. This functional information provided by the MECT is complementary to the morphological information from a conventional CT angiography. In this article, we review the technique and applications of MECT in the evaluation of pulmonary vasculature.


Posted May 15th 2019

Management of asymptomatic, well-differentiated PNETs: results of the Delphi consensus process of the Americas Hepato-Pancreato-Biliary Association.

Scott A. Celinski, M.D.

Scott A. Celinski, M.D.

Mansour, J. C., K. Chavin, G. Morris-Stiff, S. G. Warner, K. Cardona, Z. V. Fong, A. Maker, S. K. Libutti, R. Warren, C. St Hill, S. Celinski, P. Newell, Q. P. Ly, J. Howe and N. Coburn (2019). “Management of asymptomatic, well-differentiated PNETs: results of the Delphi consensus process of the Americas Hepato-Pancreato-Biliary Association.” HPB (Oxford) 21(5): 515-523.

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BACKGROUND: Variation in the management of PNETs exist due to the limited high-level evidence to guide clinical practice. The aim of this work is to generate consensus guidelines with a Delphi process for managing PNETs. METHODS: A panel of experts reviewed the surgical literature and scored a set of clinical case statements using a web-based survey to identify areas of agreement and disagreement. Results of the survey were discussed after each round of review. This cycle was repeated until no further likelihood of reaching consensus existed. RESULTS: Twenty-two case statements related to surgical indications, preoperative biopsy, extent of resection, type of surgery, and tumor location were scored. Using a pre-defined definition of consensus, the panel achieved consensus on the following: i) resection is not recommended for <1 cm lesions; ii) resection is recommended for lesions greater than 2 cm; iii) lymph node dissection is recommended for radiographically-suspicious nodes with splenectomy for distal lesions; iv) tumor enucleation and central pancreatectomy are acceptable when technically feasible. No consensus was reached regarding issues of preoperative biopsy or 1-2 cm tumors. CONCLUSIONS: Using a structured, validated system for identifying consensus, an expert panel identified areas of agreement regarding critical management decisions for patients with PNET. Issues without consensus warrant additional clinical investigation.


Posted May 15th 2019

Anomalous left anterior descending artery diagnosed on pulmonary artery computed tomography.

Andrew L. Juergens, M.D.

Andrew L. Juergens, M.D.

Kim, J., T. Bergman and A. L. Juergens (2019). “Anomalous left anterior descending artery diagnosed on pulmonary artery computed tomography.” Am J Emerg Med. Apr 12. [Epub ahead of print].

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Typically, the left anterior descending artery (LAD) and left circumflex artery (LCX) arise from the left main coronary artery. However, uncommon coronary anomalies may be found in clinical practice. This case presents with a rare finding where the LAD originates from the right coronary artery (RCA) separately from the LCX and takes an interarterial pathway to reach its perfusion territory. A 49-year-old Hispanic female with hypertension and diabetes mellitus presented to the emergency department with a 7-day history of chest pain. She denied nausea, diaphoresis, syncope, or other symptoms. A grade 3 out of 6 systolic murmur was noted on physical examination. Computed tomography of the pulmonary arteries (CTPA) revealed that the patient had no left main coronary artery. The patient’s LAD arose from the proximal RCA and took an inter-arterial course. Subsequent coronary catheterization showed no stenosis of the coronary arterial system. The patient’s chest pain subsided during the course of her admission and she was deemed stable for discharge with close cardiology follow up. In general, coronary artery anomalies are an uncommon finding in clinical practice. However, it is important to realize the different pathways of coronary artery anomalies because those with the inter-arterial subtype, such as our patient, may result in sudden cardiac death. All cases of clinically suspected inter-arterial coronary artery anomalies are recommended to undergo imaging studies to help visualize anatomic features as a guide for further management. This case represents the first reported diagnosis of this type of anomalous coronary artery on CTPA.


Posted May 15th 2019

A Model for Basic Emotions Using Observations of Behavior in Drosophila

James A. Bourgeois, M.D.

James A. Bourgeois, M.D.

Gu, S., F. Wang, N. P. Patel, J. A. Bourgeois and J. H. Huang (2019). “A Model for Basic Emotions Using Observations of Behavior in Drosophila.” Front Psychol Apr 24;10:781:eCollection 2019.

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Emotion plays a crucial role, both in general human experience and in psychiatric illnesses. Despite the importance of emotion, the relative lack of objective methodologies to scientifically studying emotional phenomena limits our current understanding and thereby calls for the development of novel methodologies, such us the study of illustrative animal models. Analysis of Drosophila and other insects has unlocked new opportunities to elucidate the behavioral phenotypes of fundamentally emotional phenomena. Here we propose an integrative model of basic emotions based on observations of this animal model. The basic emotions are internal states that are modulated by neuromodulators, and these internal states are externally expressed as certain stereotypical behaviors, such as instinct, which is proposed as ancient mechanisms of survival. There are four kinds of basic emotions: happiness, sadness, fear, and anger, which are differentially associated with three core affects: reward (happiness), punishment (sadness), and stress (fear and anger). These core affects are analogous to the three primary colors (red, yellow, and blue) in that they are combined in various proportions to result in more complex “higher order” emotions, such as love and aesthetic emotion. We refer to our proposed model of emotions as called the “Three Primary Color Model of Basic Emotions.”


Posted May 15th 2019

Updates on the pathophysiology and therapeutic targets for hepatic encephalopathy.

Jamil S. Alsahhar, M.D.

Jamil S. Alsahhar, M.D.

Alsahhar, J. S. and R. S. Rahimi (2019). “Updates on the pathophysiology and therapeutic targets for hepatic encephalopathy.” Curr Opin Gastroenterol 35(3): 145-154.

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PURPOSE OF REVIEW: Hepatic encephalopathy is one of the most debilitating clinical manifestations of cirrhosis and associated with increased morbidity and mortality. Treatment modalities available include the nonabsorbable disaccharides (lactulose) and the nonabsorbable antibiotics (rifaximin). RECENT FINDINGS: Newer therapeutic targets under evaluation include ammonia scavengers (ornithine phenylacetate) and modulation of gut microbiota (fecal microbiota transplantation). SUMMARY: This review will focus on the pathophysiology of hepatic encephalopathy along with an update on therapeutic targets under investigation.