visitor # 1 since May 2003
JN : AJR Am J Roentgenol. 2008 Jun;190(6):1453-61.
TI : Patient doses in radiographic examinations in 12 countries in Asia, Africa, and Eastern Europe: initial results from IAEA projects.
AU : Muhogora WE, Ahmed NA, Almosabihi A, Alsuwaidi JS, Beganovic A, Ciraj-Bjelac O, Kabuya FK, Krisanachinda A, Milakovic M, Mukwada G, Ramanandraibe MJ, Rehani MM, Rouzitalab J, Shandorf C.
EN-AB: OBJECTIVE: The purpose of this study was to survey image quality and the entrance surface air kerma for patients in radiographic examinations and to perform comparisons with diagnostic reference levels. SUBJECTS AND METHODS: In this multinational prospective study, image quality and patient radiation doses were surveyed in 12 countries in Africa, Asia, and Eastern Europe, covering 45 hospitals. The rate of unsatisfactory images and image quality grade were noted, and causes for poor image quality were investigated. The entrance surface doses for adult patients were determined in terms of the entrance surface air kerma on the basis of X-ray tube output measurements and X-ray exposure parameters. Comparison of dose levels with diagnostic reference levels was performed. RESULTS: The fraction of images rated as poor was as high as 53%. The image quality improved up to 16 percentage points in Africa, 13 in Asia, and 22 in Eastern Europe after implementation of a quality control (QC) program. Patient doses varied by a factor of up to 88, although the majority of doses were below diagnostic reference levels. The mean entrance surface air kerma values in mGy were 0.33 (chest, posteroanterior), 4.07 (lumbar spine, anteroposterior), 8.53 (lumbar spine, lateral), 3.64 (abdomen, anteroposterior), 3.68 (pelvis, anteroposterior), and 2.41 (skull, anteroposterior). Patient doses were found to be similar to doses in developed countries and patient dose reductions ranging from 1.4% to 85% were achieved. CONCLUSION: Poor image quality constitutes a major source of unnecessary radiation to patients in developing countries. Comparison with other surveys indicates that patient dose levels in these countries are not higher than those in developed countries. (NO 18492891)
JN : J Med Assoc Thai. 2007 Apr;90(4):823-8.
TI : Radiation dose to medical staff in interventional radiology.
AU : Oonsiri S, Jumpangern C, Sanghangthum T, Krisanachinda A, Suriyapee S.
EN-AB: OBJECTIVE: The purposes of the present study were to determine the dose to medical staff in interventional radiology at different locations on the body measured by thermoluminescent dosimeter (TLD) and to relate the medical staff dose to patient dose measured by the dose-area product (DAP) meter. MATERIAL AND METHOD: The present study covered 42 patients in three interventional radiology procedures with three x-ray machines. Thermoluminescent dosimeters were stuck at eight positions on the radiologist's skin during the procedure. In addition, direct reading from the DAP meter placed in front of the collimator of the x-ray tube, was recorded to estimate the patient radiation dose. RESULTS: The surface dose to the primary radiologist showed maximum value at the left forearm of 407 microGy. The ratios between the maximum interventional radiologist surface dose and patient dose are 12.88 microGy per 10 Gycm2 for transarterial oily chemoembolization TOCE (Siemens Polystar), 22.58 microGy per 10 Gycm2 for transarterial oily chemoembolization TOCE (Siemens Neurostar), 148.29 microGy per 10 Gycm2 for percutaneous transhepatic biliary drainage PTBD (Siemens Polystar) and 100.46 microGy per 10 Gycm2for endoscopic retrograde cholangiopancreatography ERCP (GE Advantx). CONCLUSION: The interventional radiologist surface dose can be estimated from the mentioned ratio if the patient dose is measured. This will help the radiologists to avoid receiving an excess dose during their work. (NO 17487142)
JN : J Infect Dis. 2006 Sep 1;194(5):642-50. Epub 2006 Jul 18.
TI : Changes in body composition and mitochondrial nucleic acid content in patients switched from failed nucleoside analogue therapy to ritonavir-boosted indinavir and efavirenz.
AU : Boyd MA, Carr A, Ruxrungtham K, Srasuebkul P, Bien D, Law M, Wangsuphachart S, Krisanachinda A, Lerdlum S, Lange JM, Phanuphak P, Cooper DA, Reiss P.
EN-AB: BACKGROUND: Body composition changes complicate antiretroviral therapy. Improvements in lipoatrophy after a switch in nucleoside reverse-transcriptase inhibitors (NRTIs) have been demonstrated. We investigated 60 patients switching from failed NRTIs to ritonavir-boosted indinavir and efavirenz. METHODS: Body composition (assessed by dual-energy x-ray absorptiometry scan and by single-slice computed tomography of the abdomen through the level of the fourth lumbar vertebra [L4] and the mid-right thigh) and fasted metabolics were measured at the baseline time-point at switch and at weeks 48 and 96 thereafter. Mitochondrial DNA and RNA were extracted from right-thigh subcutaneous fat and peripheral-blood mononuclear cells (PBMCs) at weeks 0 and 48. The primary end point was the change in mean limb fat over 48 weeks. RESULTS: At week 96, we observed increases in mean (standard deviation [SD]) limb fat (+620  g; P=.003), L4 subcutaneous adipose tissue (+20  cm(2); P<.001), mid-thigh subcutaneous adipose tissue (+5  cm(2); P<.001), and L4 visceral adipose tissue (+11  cm(2); P=.01), but we also observed reduced lean limb mass (-831 [1,100] g; P=.3). Mean (SD) mtDNA content in subcutaneous fat and in PBMCs increased (+109  and +45  copies/cell, respectively). Improved virological control or immune recovery did not explain the results. Triglyceride, total cholesterol, estimated low-density lipoprotein cholesterol, ratio of total cholesterol to high-density lipoprotein cholesterol, and blood glucose levels deteriorated (i.e., had increased by 206%, 67%, 58%, 19%, and 6%, respectively, at week 96). CONCLUSIONS: This regimen was associated with statistically significant but clinically modest increases in peripheral fat, visceral fat, and mitochondrial nucleic acid content. A predominantly adverse metabolic profile developed. (NO 16897663)
JN : Radiology. 2006 Sep;240(3):828-34. Epub 2006 Jul 12.
TI : Dose reduction in CT while maintaining diagnostic confidence: diagnostic reference levels at routine head, chest, and abdominal CT--IAEA-coordinated research project.
AU : Tsapaki V, Aldrich JE, Sharma R, Staniszewska MA, Krisanachinda A, Rehani M, Hufton A, Triantopoulou C, Maniatis PN, Papailiou J, Prokop M.
EN-AB: PURPOSE: To measure radiation doses for computed tomography (CT) of the head, chest, and abdomen and compare them with the diagnostic reference levels, as part of the International Atomic Energy Agency Research coordination project. MATERIALS AND METHODS: The local ethics committees of all participating institutions approved the study protocol. Written informed consent was obtained from all patients. All scanners were helical single-section or multi-detector row CT systems. Six hundred thirty-three patients undergoing head (n = 97), chest (n = 243), or abdominal (n = 293) CT were included. Collected data included patient height, weight, sex, and age; tube voltage and tube current-time product settings; pitch; section thickness; number of sections; weighted or volumetric CT dose index; and dose-length product (DLP). The effective dose was also estimated and served as collective dose estimation data. RESULTS: Mean volumetric CT dose index and DLP values were below the European diagnostic reference levels: 39 mGy and 544 mGy . cm, respectively, at head CT; 9.3 mGy and 348 mGy . cm, respectively, at chest CT; and 10.4 mGy and 549 mGy . cm, respectively, at abdominal CT. Estimated effective doses were 1.2, 5.9, and 8.2 mSv, respectively. CONCLUSION: Comparison of CT results with diagnostic reference levels revealed the need for revisions, partly because the newer scanners have improved technology that facilitates lower patient doses. (c) RSNA, 2006. (NO 16837668)
JN : J Med Assoc Thai. 2005 Sep;88 Suppl 4:S235-41.
TI : The difference among stress and rest normal reference databases using non-corrected, scatter corrected, and scatter with attenuation corrected Bull's eye myocardial perfusion scintigraphy in both genders.
AU : Tepmongkol S, Pasawang P, Krisanachinda A, Srimahachota S.
EN-AB: OBJECTIVES: To compare 3 types of Bull's eye normal reference maps; non-corrected, scatter corrected, and scatter with attenuation corrected Bull's eye in both genders. MATERIAL AND METHOD: Sixty-seven normal healthy males and females volunteered for the present study. After screening tests to identify low post-test (exercise EKG) likelihood of coronary artery disease, 41 subjects (20 males and 21 females) had stress and rest myocardial perfusion scintigraphy (99mTc-sestamibi). The data were reconstructed by filtered back projection reconstruction in three ways as follows; (1) non-correction (NoC), (2) scatter elimination only (SC), (3) scatter elimination and attenuation correction (SC+AC). Three sets of reconstructed data of both stress and resting studies were added into 6 sets of Bull's eye. The data of each Bull's eve were normalized to 100% of the maximum count. Percentage of uptake in each area was compared by t-test statistics. RESULTS: Stress and rest count distribution of NoC and SC sets were lowest at the inferior wall, followed by the septal wall, anterior wall, and lateral wall in both genders. In the SC+AC sets; septum and lateral walls showed more uptake than anterior and inferior walls. A significant difference of percentage uptake between stress and rest images at septum in NoC and SC images in male and in SC image in female was observed. No difference was seen in the SC+AC groups. CONCLUSION: There was similarity of count distribution between NoC and SC images. SC+AC caused more uniform image. However; some non-uniformity was observed. The use of sex-independent SC+AC bull's eye is possible. Stress study can be omitted for bull's eye collection of normal files. (NO 16623035)
AU : Chaiwatanarat T, Laorpatanaskul S, Poshyachinda M, Boonvisut S, Buachum V, Krisanachinda A, Suvanapha R.
TI : Deconvolution analysis of renal blood flow: evaluation of postrenal transplant complications.
JN : Journal of Nuclear Medicine 1994 Nov ; 35 (11) : 1792-6
EN-AB: Medical complications after renal transplantation cause problems in treatment decision making. To differentiate acute tubular necrosis from acute rejection when it occurs in the early posttransplant period is difficult. Renal scintigraphy offers a noninvasive means for renal blood flow (RBF) and renal function assessment. METHODS: This retrospective study of RBF and renal function evaluation after kidney transplantation is an attempt to calculate the "renal vascular transit time" from the 99mTc-diethylenetriaminepentaaacetic acid renal vascular flow with a deconvolution technique. The results of 102 studies on 38 graft recipients were evaluated. Of these, 19 were diagnosed as acute rejection, 12 as acute tubular necrosis, 4 as chronic rejection, 1 as vesicoureteric reflux, 1 as recurrent immunoglobulin A nephropathy, 1 as iliac vein thrombosis, 1 as cyclosporine nephrotoxicity and 63 as normal. All diagnoses were established by clinical and/or pathologic criteria. RESULTS: With renal vascular transit times more than 12.8 secm the sensitivity and specificity for the detection of acute rejection was 95 and 94, respectively. The sensitivity and specificity for the differential diagnosis of acute rejection against acute tubular necrosis was 95 and 92, respectively. CONCLUSION: The use of renal vascular transit time in addition to 131I-labeled hippuran renogram provides a promising diagnostic parameter to differentiate between acute rejection and acute tubular necrosis. (NO 02258)
AU : Krisanachinda A.
TI : Software phantom.
JN : Thai J Radiol 1990 Jan-Apr ; 27 (1) : 85-90
EN-AB: A set of clinical dynamic cardiac studies, software phantom, was implemented on different computer systems for the purpose of quality control of analysis software. The software phantoms of normal and abnormal gated cardiac blood pool studies were transferred between systems for the analysis of the left ventricle ejection fraction (LVEF). The results obtained for 10 software phantoms using commerical and user's development analysis softwares were similar in some phatoms but widely divergent in others. The other purpose of software phantom is used for the nuclear medicine personnels training aids, the periodical check of the upgrade and also the current analysis software. This soft ware phantom should be available at each computer center for nuclear medicine imaging. (NO 02439)
AU : Krisanachinda A, Soni PS, Kim JH, Herath KB, Khan UH.
TI : Aspects of establishing a national programme on instrument quality control : results of the coordinated research programme in Asia.
CONF : International Symposium on Dynamic Studies in Nuclear Medicine, 1988 Aug 15-19, IAEA Vienna, Austria
JN : Thai J Radiol 1989 Jan ; 26 (1) : 83-84
EN-AB: not available (NO 01614)
AU : Krisanachinda A, Chanachai R, Boonyaprapa S.
TI : Quality control of camera-computer system in Thailand.
JN : Thai J Radiol 1987 Apr ; 24 (2) : 123-128
EN-AB: not available (NO 01762)
AU : Krisanachinda A.
TI : Quality control of radionuclide imaging systems in Thailand.
CONF : Congress of Asean Association of Radiology. 3 rd, 1984 Dec 12-14, Manila, Philippines
JN : Thai J Radiol 1985 Apr ; 22 (1) : 65-67
TH-AB: ทบวงการพลังงานปรมาณูระหว่างประเทศ (IAEA) ได้ริเริ่มโครงการควบคุมคุณภาพของระบบถ่ายภาพราดิโอนิวไคลด์ขึ้นในประเทศไทย โดยมีวัตถุประสงค์ที่จะให้ผู้ใช้เครื่องเพิ่มความระมัดระวังในการใข้เครื่องโดยถูกวิธี ในขณะเดียวกันก็ได้กระตุ้นให้มีการทดสอบคุณภาพเป็นประจำและบันทึกผลการทดสอบไว้เพื่อเป็นข้อมูลอ้างอ ิงในการเปรียบเทียบกับข้อมูลในระยะต่อไป ทบวงการฯ ได้จัดทำหนังสือคู่มือเรื่อง การควบคุมคุณภาพของเครื่องมือเวชศาสตร์นิวเคลียร์ขึ้น เพื่อสนับสนุนโครงการดังกล่าว โดยได้แนะนำวิธการทดสอบอ้างอิง (referencen test)การทดสอบก่อนรับเครื่อง (acceptance test)และการทดสสอบประจำ (routine test) เป็นการทดสอบ 2 อย่าง คือ การปรับค่าพลังงาน (energy calibration) และการทดความสม่ำเสมอของภาพ (uniformity) ซึ่งจะต้องทดสอบทุกวันก่อนการใช้เครื่องประกอบการวินิจฉัยโรค เมื่อมีการเปลี่ยนแปลงเกิดขึ้นจากผลการทดสอบ ควรหาสาเหตุและรีบดำเนินการแก้ไข การทดสอบอ้างอิงประกอบด้วย การทดสอบความสม่ำเสมอของภาพ เมื่อปรับหน้าต่างให้อยู่ต่ำกว่าค่าโฟโตพีค และสูง กว่าค่าโฟโตพีค (offset window) การทดสอบดังกล่าว จะแสดงการทำงานของหลอดโฟโตมัลติพลายเออร์ นอกจากนั้นยังมีการทดสอบขีดความสามารถในการแสดงรายละเอียดของภาพ (resolution check) การทดสอบการตอบสนองของเครื่องมือใช้อัตราค่านับวัดสูงมาก สำหรับเครื่องแกมมาคาเมราที่ดีควรให้รายละเอียดของภาพและความสม่ำเสมอของภาพเท่ากันไม่ว่าจะใช้อัตรา ค่านับวัดสูงหรือต่ำ (NO 00023)
AU : Krisanachinda A, Poshyachinda M.
TI : Some aspects of quality control of nuclear medicine instruments at Chulalongkorn Hospital, Bangkok, Thailand.
CONF : Seminar on Quality Assurance in the Use of Nuclear Medicine Instruments, 1982 Jul 19-22, Bangkok, Thailand
JN : Thai J Radiol 1983 Apr ; 20 (1) : 53-59
EN-AB: Division of Nuclear Medicine, Chulalongkorn Hospital Medical School is one of a pilot laboratory for the RCA survey of nuclear instrumentations. The survey program involves the preventive maintenance records and evaluation of instrumentation including the environmental conditions. This communication represents part of the above studies in addition to the evaluation of the quality control tests of the counting and imaging systems of the nuclear medicine equipments in this hospital. (NO 00021)
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