Usefulness of Respiratory-Gated ¹⁸F-FDG PET/CT in Detecting Upper Abdominal Fever Focus / 대한핵의학회잡지

Respiratory-gated ¹⁸F-fluorodeoxygluocse (¹⁸F-FDG) PET/CT has been successfully used to better localize malignancies in the lung or upper abdominal organs. However, clinical usefulness of respiratory-gated ¹⁸F-FDG PET/CT in detection of fever focus has not been reported yet. A 68-year-old male patient with a history of living donor liver transplantation and biliary stenting was referred for ¹⁸F-FDG PET/CT due to fever of unknown origin (FUO). To find the accurate fever focus, respiratory-gated and non-gated ¹⁸F-FDG PET/CT was performed. Respiratory-gated PET/CT readily revealed prominent hypermetabolic lesion in the distal common bile duct (CBD) area where previous surgical graft was in situ. Maximum standardized uptake value (SUVmax) and SUVratio (SUR) were greater in the gated PET/CT (SUVmax 5.4 and SUR 3.5) than in the non-gated PET/CT (SUVmax 4.6 and SUR 3.0). Fever dramatically subsided after removal of the graft in the CBD. This case report implies that respiratory-gated ¹⁸F-FDG PET/CT can visualize upper abdominal fever focus with better contrast than the conventional non-gated method.

Influence of active breathing control on the dose distribution in the target of forward whole-breast intensity-modulated radiotherapy after breast conserving surgery / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To explore the influence of intrafraction and interfraction target displacement on the dose distribution in the target of forward whole-breast intensity-modulated radiotherapy (IMRT) assisted by active breathing control (ABC).</p><p><b>METHODS</b>Each of the selected patient who had received breast conserving surgery was immobilized and received the primary CT simulation assisted by ABC device to get five sets of CT images in three different breathing status, including free breathing (FB) (one set), moderate deep inspiration breathing hold (mDIBH)(two sets) and deep expiration breathing hold (DEBH) (2 sets). After 10 to 15 fractions of radiation, the repeated CT simulation was completed and the same five sets of CT images were obtained at FB, mDIBH, and DEBH, respectively. In the Pinnacle3 treatment planning system, the forward IMRT planning was completed on the first set of mDIBH CT images from the primary CT simulation, and the planning was separately copied by the special system order to the second set of CT images from the primary CT simulation and to the first set of CT images from the repeated CT simulation, keeping the primary angle, direction, size and shape of the MLC field and prescribed dose un-changed. the volumes covered by selected high dose area in the selected segment were compared.</p><p><b>RESULTS</b>In the planning based on the first set of mDIBH CT images from the primary CT simulation, the volume irradiated by equal and more than 103% of prescribed dose in the segment was (1.16 +/- 0.39) cm3, and the volumes were (3.88 +/- 1.07) cm3 and (51.66 +/- 8.68) cm3 in the plannings copied from the first set of mDIBH CT images from the primary CT simulation respectively to the second set of CT images from the primary CT simulation and first set of CT images from the repeat CT simulation, the difference of the volume in the two plannings based on the two set mDIBH CT image from the primary CT simulation was not statistically significant (t = -1.672, P = 0.103). The difference of the volume in the two plannings based on the two sets of mDIBH CT images respectively from the primary and repeat CT simulations had a significant difference (t = -5.728, P < 0.01).</p><p><b>CONCLUSION</b>If the same threshold of mDIBH is maintained during IMRT after breast conserving surgery, the influence of the intrafraction target displacement on the dose distribution is not significant. However, if set-up error is not adjusted, the interfraction change of position of the segment given to cover the high dose area in the IMRT planning will be significant, resulting in a significant change of dose distribution in the breast.</p>

Application of electrocardiac-gating in echocardiogram analysis / 生物医学工程学杂志

To study the application of the gating technic in 2D imaging of echocardiogram, thirty normal men and twenty-five patients suspected of having heart diseases were recruited. The electrocardiac R-gating was adopted for collecting phasic images combing with interactive mode of man to computer, recognizing and calculating by computer while delineating the form and structure of heart with the use of mouse to detect the quantitative parameters of cardiac function and left ventricular volume curve. Its application can provide the information of some quantitative parameters for diagnosing the localization of early coronary heart disease and myocardial ischemia.