Interobserver Agreement for the Diagnosis of Venous Thromboembolism on Computed Tomography Chest Angiography and Indirect Venography of the Lower Extremities in Emergency Department Patients

Objectives: To determine interobserver agreement between radiologists for computed tomography (CT) angiography and venography. CT venography of the lower extremities combined with standard CT angiography of the chest may result in an increased overall diagnosis rate of venous thromboembolism (pulmonary embolism or deep venous thrombosis).
Methods: The study had a retrospective cohort design. The population consisted of emergency department patients who were evaluated for suspected pulmonary embolism. A random sample of 50 patients diagnosed and treated for venous thromboembolism and 50 age- and gender-matched patients whose CT angiograms and venograms were read as negative were enrolled. The original reading (R1) was compared with readings of two study radiologists: R2, a general radiologist, and R3, a radiologist with fellowship training in cross-sectional imaging. All readers were blinded to each other.
Results: Both R2 and R3 found both CT angiogram and venogram components technically adequate in 95% (95% CI = 89% to 98%) and 86% (95% CI = 78% to 92%) of studies, respectively. The agreement was very good for CT angiography (lowest agreement = 92%; lowest κ = 0.83) and was good for CT venography (85%, κ = 0.65). In nine cases, R1 read the CT angiogram as negative but the venogram as positive for DVT, whereas both R2 and R3 read both components as negative in four of these nine, suggesting a false-positive isolated DVT rate of 44% (95% CI = 19% to 73%). In no case did R1 read both scan components as negative when R2 and R3 agreed on presence of pulmonary embolism or DVT.
Conclusions: Diagnosis of pulmonary embolism on CT angiography is more reliable than diagnosis of isolated DVT on CT venography.     

Fat and water separation in balanced steady-state free precession using the Dixon method.

In this work the feasibility of separating fat and water signals using the balanced steady-state free precession (SSFP) technique is demonstrated. The technique is based on the observation (Scheffler and Hennig, Magnetic Resonance in Medicine 2003;49:395-397) that at the nominal values of TE = TR/2 in SSFP imaging, phase coherence can be achieved at essentially only two orientations (0 degrees and 180 degrees ) relative to the RF pulses in the rotating frame, under the assumption of TR < T2, and independently of the SSFP angle. This property allows in-phase and out-of-phase SSFP images to be obtained by proper choices of the center frequency offset, and thus allows the Dixon subtraction method to be utilized for effective fat-water separation. The TR and frequency offset for optimal fat-water separation are derived from theories. Experimental results from healthy subjects, using a 3.0 Tesla system, show that nearly complete fat suppression can be accomplished.     

Validity and reliability of the Bengali version of the Hepatitis Quality of Life Questionnaire

Purpose  

Hepatitis B virus (HBV) is endemic in Bangladesh, and the quality of life (QoL) of these patients remains unknown as there is no instrument available in the native language. In this study, we translated the 56-item Hepatitis Quality of Life Questionnaire (HQLQ) into Bengali and evaluated its validity and reliability.     

Biphasic Dose Response in Low Level Light Therapy

The use of low levels of visible or near infrared light for reducing pain, inflammation and edema, promoting healing of wounds, deeper tissues and nerves, and preventing cell death and tissue damage has been known for over forty years since the invention of lasers. Despite many reports of positive findings from experiments conducted in vitro, in animal models and in randomized controlled clinical trials, LLLT remains controversial in mainstream medicine. The biochemical mechanisms underlying the positive effects are incompletely understood, and the complexity of rationally choosing amongst a large number of illumination parameters such as wavelength, fluence, power density, pulse structure and treatment timing has led to the publication of a number of negative studies as well as many positive ones. A biphasic dose response has been frequently observed where low levels of light have a much better effect on stimulating and repairing tissues than higher levels of light. The so-called Arndt-Schulz curve is frequently used to describe this biphasic dose response. This review will cover the molecular and cellular mechanisms in LLLT, and describe some of our recent results in vitro and in vivo that provide scientific explanations for this biphasic dose response.     

PR01“A PICTURE SPEAKS A THOUSAND WORDS”– THE USE OF DIGITAL PHOTOGRAPHY AND THE INTERNET IN MONITORING FREE TISSUE TRANSFER

Purpose Post operative monitoring is crucial for the success of microsurgical free tissue transfer. Sophisticated and expensive methods are available for monitoring. We propose a novel technique using digital photography and the internet as a reliable and cost effective method to monitor free tissue transfers. Methods 163 micro‐vascular procedures were monitored using this technique over 8 months. Serial photographs taken to show flap color. Capillary refill time, pin prick‐ bleed time and color and hand held Doppler signal was recorded in the movie mode of a standard 5 mega pixel camera with duration of 15 seconds. Data was sent to the surgeon at regular intervals and or as deemed necessary. Results Analysis of the 67 cases is presented. 5 re‐explorations were done. The early diagnosis of venous congestion was possible using this technique. Timely intervention contributed to the success of the re‐explorations and these flaps could be salvaged. The file size of images was in the range of 1 MB–6 MB. The file size of an entire set of images ranged about 7 MB–9 MB. These were sent across the ADSL internet lines. Conclusion The use of the digital images and the internet allow reconstructive surgeons to have a reliable picture of the state of their free tissue transfers. This permits decrease in observer error and saves valuable time which otherwise needs to be spent to verify situations of doubt and offers an ideal solution to the logistic problem of having to visit the patient in case of doubt.