1.Successful treatment of ischemic stroke associated with brachiocephalic artery stenosis using alteplase
Yuta MITANI ; Zen KOBAYASHI ; Eijiro HATTORI ; Yoshiyuki NUMASAWA ; Shoichiro ISHIHARA ; Hiroyuki TOMIMITSU ; Shuzo SHINTANI
Journal of Rural Medicine 2021;16(2):123-125
Introduction: Brachiocephalic artery stenosis rarely causes right hemispheric infarction with associated left hemiparesis. To date, there have been no reported cases of stroke associated with brachiocephalic artery stenosis that were successfully treated with recombinant tissue-type plasminogen activator (rt-PA), alteplase.Case Report: An 80-year-old woman presented with left hemiparesis. Brain computed tomography showed no hemorrhage, and computed tomography angiography demonstrated brachiocephalic artery stenosis. Alteplase was administered based on a diagnosis of ischemic stroke. Brain magnetic resonance imaging showed multiple acute infarctions. Thereafter, the blood pressure of the right arm was found to be lower than that of the left arm. The patient’s neurological deficits gradually improved; she was eventually able to walk again and was thus discharged home.Conclusion: While the combination of left hemiparesis and a decrease in blood pressure in the right arm are well known in patients with stroke associated with Stanford type A aortic dissections, it may also occur in patients with stroke due to brachiocephalic artery stenosis. Unlike stroke associated with Stanford type A aortic dissections, stroke due to brachiocephalic artery stenosis may be treated with alteplase.
2.A novel method for determining dose distribution on panoramic reconstruction computed tomography images from radiotherapy computed tomography
Hiroyuki OKAMOTO ; Madoka SAKURAMACHI ; Wakako YATSUOKA ; Takao UENO ; Kouji KATSURA ; Naoya MURAKAMI ; Satoshi NAKAMURA ; Kotaro IIJIMA ; Takahito CHIBA ; Hiroki NAKAYAMA ; Yasunori SHUTO ; Yuki TAKANO ; Yuta KOBAYASHI ; Hironori KISHIDA ; Yuka URAGO ; Masato NISHITANI ; Shuka NISHINA ; Koushin ARAI ; Hiroshi IGAKI
Imaging Science in Dentistry 2024;54(2):129-137
Purpose:
Patients with head and neck cancer (HNC) who undergo dental procedures during radiotherapy (RT) face an increased risk of developing osteoradionecrosis (ORN). Accordingly, new tools must be developed to extract critical information regarding the dose delivered to the teeth and mandible. This article proposes a novel approach for visualizing 3-dimensional planned dose distributions on panoramic reconstruction computed tomography (pCT) images.
Materials and Methods:
Four patients with HNC who underwent volumetric modulated arc therapy were included. One patient experienced ORN and required the extraction of teeth after RT. In the study approach, the dental arch curve (DAC) was defined using an open-source platform. Subsequently, pCT images and dose distributions were generated based on the new coordinate system. All teeth and mandibles were delineated on both the original CT and pCT images. To evaluate the consistency of dose metrics, the Mann-Whitney U test and Student t-test were employed.
Results:
A total of 61 teeth and 4 mandibles were evaluated. The correlation coefficient between the 2 methods was 0.999, and no statistically significant difference was observed (P>0.05). This method facilitated a straightforward and intuitive understanding of the delivered dose. In 1 patient, ORN corresponded to the region of the root and the gum receiving a high dosage (approximately 70 Gy).
Conclusion
The proposed method particularly benefits dentists involved in the management of patients with HNC. It enables the visualization of a 3-dimensional dose distribution in the teeth and mandible on pCT, enhancing the understanding of the dose delivered during RT.