1.Currrent Source Analysis of Interictal Spikes in a Patient With Ictal Grimacing.
Jongsoo KANG ; Oh Young KWON ; Kwangsub LEE ; Heeyoung KANG ; Kyusik KANG ; Ki Jong PARK ; Nack Cheon CHOI ; Byeong Hoon LIM
Journal of the Korean Neurological Association 2009;27(2):183-186
Facial grimacing can be a manifestation of complex partial seizures from the temporal lobe. We observed a case of seizure with facial grimacing and partial loss of consciousness during an electroencephalography recording. The recording revealed interictal spikes on the left-sided inferior temporal electrodes and ictal discharges starting on the same electrodes. The current source appeared to be in the inferior and lateral temporal areas of the left cerebral hemisphere. These results show that it is possible to localize the current sources responsible for interictal spikes.
Cerebrum
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Electrodes
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Electroencephalography
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Humans
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Seizures
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Temporal Lobe
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Unconsciousness
2.Comparison of the Efficacy of 2D Dosimetry Systems in the Pre-treatment Verification of IMRT.
Chae Seon HONG ; Jongsoo LIM ; Sang Gyu JU ; Eunhyuk SHIN ; Youngyih HAN ; Yong Chan AHN
The Journal of the Korean Society for Therapeutic Radiology and Oncology 2009;27(2):91-102
PURPOSE: To compare the accuracy and efficacy of EDR2 film, a 2D ionization chamber array (MatriXX) and an amorphous silicon electronic portal imaging device (EPID) in the pre-treatment QA of IMRT. MATERIALS AND METHODS: Fluence patterns, shaped as a wedge with 10 steps (segments) by a multi-leaf collimator (MLC), of reference and test IMRT fields were measured using EDR2 film, the MatriXX, and EPID. Test fields were designed to simulate leaf positioning errors. The absolute dose at a point in each step of the reference fields was measured in a water phantom with an ionization chamber and was compared to the dose obtained with the use of EDR2 film, the MatriXX and EPID. For qualitative analysis, all measured fluence patterns of both reference and test fields were compared with calculated dose maps from a radiation treatment planning system (Pinnacle, Philips, USA) using profiles and gamma evaluation with 3%/3 mm and 2%/2 mm criteria. By measurement of the time to perform QA, we compared the workload of EDR2 film, the MatriXX and EPID. RESULTS: The percent absolute dose difference between the measured and ionization chamber dose was within 1% for the EPID, 2% for the MatriXX and 3% for EDR2 film. The percentage of pixels with gamma%>1 for the 3%/3 mm and 2%/2 mm criteria was within 2% for use of both EDR2 film and the EPID. However, differences for the use of the MatriXX were seen with a maximum difference as great as 5.94% with the 2%/2 mm criteria. For the test fields, EDR2 film and EPID could detect leaf-positioning errors on the order of -3 mm and -2 mm, respectively. However it was difficult to differentiate leaf-positioning errors with the MatriXX due to its poor resolution. The approximate time to perform QA was 110 minutes for the use of EDR2 film, 80 minutes for the use of the MatriXX and approximately 55 minutes for the use of the EPID. CONCLUSION: This study has evaluated the accuracy and efficacy of EDR2 film, the MatriXX and EPID in the pre-treatment verification of IMRT. EDR2 film and the EPID showed better performance for accuracy, while the use of the MatriXX significantly reduced measurement and analysis times. We propose practical and useful methods to establish an effective QA system in a clinical environment.
Electronics
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Electrons
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Silicon
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Water