Basic Physics and Imaging Characteristics of Ultrasound

The imaging characteristics of diagnostic ultrasound (US) are determined by the ultrasonic properties of tissue. The velocity of propagation of US and the attenuation are the 2 most important parameters. These determine the frequency with which the tissues may be imaged, which in turn sets a fundamental limit on the axial and the lateral resolution. Ultrasonic imaging equipment is designed on the premise that the ultrasonic energy propagates through tissue in a straight line and that the ultrasonic beam is very narrow. In fact, the ultrasonic energy propagates through tissue as a beam of finite dimensions set by the physical dimensions of the transducer, the way it is constructed, and the way it is energized. Also, the velocity of propagation in different tissues varies and this can lead to deviation of the ultrasonic beam from the assumed direction of propagation. This breakdown in assumptions leads to the creation of artifacts that must be appreciated in the interpretation of ultrasonic images. For this reason skilled interpreters of ultrasonic images follow 3 golden rules: never make an interpretation on a single image; just because a feature is displayed do not consider that it is necessarily real; and just because a feature is not displayed do not consider that it is necessarily not there.     

The Surgeon as a Scientist

Hellenic Journal of Surgery -     

Surgeon reimbursement for trauma care

BACKGROUND: Trauma care is a well-known financial burden for hospitals, yet reimbursement for the surgeon has not been reported. METHODS: For 1999, the percent of the surgeons' bills reimbursed for general surgery services (gPR) was compared with that for trauma services (tPR). Mean tPR for various groups were compared. Factors predictive of tPR lower than gPR were identified. RESULTS: The gPR was 49%, and, for 371 trauma patients, tPR was 45% (P = 0.03). The mean tPR for injury severity score (ISS) < or =10 was 48%, and for ISS > or =11, 57% (P = 0.03). Patients transferred from outside facilities did not have a significantly lower mean tPR. Penetrating trauma (odds ratio 3.7, P = 0.008) was predictive of tPR lower than gPR. CONCLUSIONS: Surgeon reimbursements for trauma care was significantly, yet only slightly less than for all general surgery care. Surgeons should not be reluctant to take trauma call based on perceptions of low reimbursement.     

Pathology for the HPB Surgeon

Optimal care of a patient implies a good professional understanding between all the medical personnel involved in that patient’s care. Similarly a basic understanding of the areas where surgery and pathology interact would go a long way, in clarifying the disease process in the patient. This review aims to cover a few topics in liver lesions, FNAC Vs core biopsy, IHC, Margin examination, and frozen sections, in order to improve the communication between these two specialities.     

Decision Analysis for the Surgeon

Surgical practice, by nature, is full of important decision making scenarios. Surgeons have begun to utilize the decision sciences as a methodology of approaching clinically relevant surgical problems. This article provides a brief overview of some of the important concepts of the decision sciences as they apply to practicing surgeons. Concepts discussed include the basic principles behind decision trees, valuing outcomes, and Markov modeling as well as the pros and cons of the decision analytic approach. Decision analysis is a valuable aid in determining answers to clinical scenarios, and understanding the principles behind this methodology is an important addition to the armamentarium of all practicing surgeons.