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1.
BMC Gastroenterol ; 24(1): 203, 2024 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-38886646

RESUMEN

Transanal total mesorectal excision (taTME) has improved the laparoscopic dissection for rectal cancer in the narrow pelvis. Although taTME has more clinical benefits than laparoscopic surgery, such as a better view of the distal rectum and direct determination of distal resection margin, an intraoperative urethral injury could occur in excision ta-TME. This study aimed to determine the feasibility and efficacy of the ta-TME with IRIS U kit surgery. This retrospective study enrolled 10 rectal cancer patients who underwent a taTME with an IRIS U kit. The study endpoints were the safety of access (intra- or postoperative morbidity). The detectability of the IRIS U kit catheter was investigated by using a laparoscope-ICG fluorescence camera system. Their mean age was 71.4±6.4 (58-78) years; 80 were men, and 2 were women. The mean operative time was 534.6 ± 94.5 min. The coloanal anastomosis was performed in 80%, and 20% underwent abdominal peritoneal resection. Two patients encountered postoperative complications graded as Clavien-Dindo grade 2. The transanal approach with IRIS U kit assistance is feasible, safe for patients with lower rectal cancer, and may prevent intraoperative urethral injury.


Asunto(s)
Estudios de Factibilidad , Complicaciones Posoperatorias , Neoplasias del Recto , Cirugía Endoscópica Transanal , Uretra , Humanos , Neoplasias del Recto/cirugía , Masculino , Femenino , Anciano , Persona de Mediana Edad , Estudios Retrospectivos , Uretra/lesiones , Uretra/cirugía , Cirugía Endoscópica Transanal/métodos , Cirugía Endoscópica Transanal/efectos adversos , Complicaciones Posoperatorias/prevención & control , Complicaciones Posoperatorias/etiología , Tempo Operativo , Proctectomía/métodos , Proctectomía/efectos adversos , Complicaciones Intraoperatorias/prevención & control , Complicaciones Intraoperatorias/etiología , Recto/cirugía , Anastomosis Quirúrgica/efectos adversos , Anastomosis Quirúrgica/métodos , Laparoscopía/métodos , Laparoscopía/efectos adversos
2.
Crit Care Med ; 51(12): 1685-1696, 2023 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-37971720

RESUMEN

OBJECTIVES: This study aimed to examine the association between ABCDEF bundles and long-term postintensive care syndrome (PICS)-related outcomes. DESIGN: Secondary analysis of the J-PICS study. SETTING: This study was simultaneously conducted in 14 centers and 16 ICUs in Japan between April 1, 2019, and September 30, 2019. PATIENTS: Adult ICU patients who were expected to be on a ventilator for at least 48 hours. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Bundle compliance for the last 24 hours was recorded using a checklist at 8:00 am The bundle compliance rate was defined as the 3-day average of the number of bundles performed each day divided by the total number of bundles. The relationship between the bundle compliance rate and PICS prevalence (defined by the 36-item Short Form Physical Component Scale, Mental Component Scale, and Short Memory Questionnaire) was examined. A total of 191 patients were included in this study. Of these, 33 patients (17.3%) died in-hospital and 48 (25.1%) died within 6 months. Of the 96 patients with 6-month outcome data, 61 patients (63.5%) had PICS and 35 (36.5%) were non-PICS. The total bundle compliance rate was 69.8%; the rate was significantly lower in the 6-month mortality group (66.6% vs 71.6%, p = 0.031). Bundle compliance rates in patients with and without PICS were 71.3% and 69.9%, respectively ( p = 0.61). After adjusting for confounding variables, bundle compliance rates were not significantly different in the context of PICS prevalence ( p = 0.56). A strong negative correlation between the bundle compliance rate and PICS prevalence ( r = -0.84, R 2 = 0.71, p = 0.035) was observed in high-volume centers. CONCLUSIONS: The bundle compliance rate was not associated with PICS prevalence. However, 6-month mortality was lower with a higher bundle compliance rate. A trend toward a lower PICS prevalence was associated with higher bundle compliance in high-volume centers.


Asunto(s)
Enfermedad Crítica , Unidades de Cuidados Intensivos , Adulto , Humanos , Enfermedad Crítica/epidemiología , Enfermedad Crítica/terapia , Mortalidad Hospitalaria , Ventiladores Mecánicos
3.
Crit Care ; 25(1): 69, 2021 02 16.
Artículo en Inglés | MEDLINE | ID: mdl-33593406

RESUMEN

BACKGROUND: Many studies have compared quality of life of post-intensive care syndrome (PICS) patients with age-matched population-based controls. Many studies on PICS used the 36-item Short Form (SF-36) health survey questionnaire version 2, but lack the data for SF-36 values before and after intensive care unit (ICU) admission. Thus, clinically important changes in the parameters of SF-36 are unknown. Therefore, we determined the frequency of co-occurrence of PICS impairments at 6 months after ICU admission. We also evaluated the changes in SF-36 subscales and interpreted the patients' subjective significance of impairment. METHODS: A prospective, multicenter, observational cohort study was conducted in 16 ICUs across 14 hospitals in Japan. Adult ICU patients expected to receive mechanical ventilation for > 48 h were enrolled, and their 6-month outcome was assessed using the questionnaires. PICS definition was based on the physical status, indicated by the change in SF-36 physical component score (PCS) ≥ 10 points; mental status, indicated by the change in SF-36 mental component score (MCS) ≥ 10 points; and cognitive function, indicated by the worsening of Short-Memory Questionnaire (SMQ) score and SMQ score at 6 months < 40. Multivariate logistic regression model was used to identify the factors associated with PICS occurrence. The patients' subjective significance of physical and mental symptoms was assessed using the 7-scale Global Assessment Rating to evaluate minimal clinically important difference (MCID). RESULTS: Among 192 patients, 48 (25%) died at 6 months. Among the survivors at 6 months, 96 patients responded to the questionnaire; ≥ 1 PICS impairment occurred in 61 (63.5%) patients, and ≥ 2 occurred in 17 (17.8%) patients. Physical, mental, and cognitive impairments occurred in 32.3%, 14.6% and 37.5% patients, respectively. Population with only mandatory education was associated with PICS occurrence (odds ratio: 4.0, 95% CI 1.1-18.8, P = 0.029). The MCID of PCS and MCS scores was 6.5 and 8.0, respectively. CONCLUSIONS: Among the survivors who received mechanical ventilation, 64% had PICS at 6 months; co-occurrence of PICS impairments occurred in 20%. PICS was associated with population with only mandatory education. Future studies elucidating the MCID of SF-36 scores among ICU patients and standardizing the PICS definition are required. Trial registration UMIN000034072.


Asunto(s)
Enfermedad Crítica/psicología , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Enfermedad Crítica/epidemiología , Femenino , Humanos , Unidades de Cuidados Intensivos/organización & administración , Unidades de Cuidados Intensivos/estadística & datos numéricos , Japón/epidemiología , Masculino , Persona de Mediana Edad , Prevalencia , Estudios Prospectivos , Calidad de Vida/psicología , Encuestas y Cuestionarios , Sobrevivientes/psicología
4.
Biol Blood Marrow Transplant ; 25(5): 981-988, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30639818

RESUMEN

Markers of inflammatory and nutritional status, such as the Controlling Nutritional Status (CONUT) score, Prognostic Nutritional Index, Glasgow Prognostic Score, and C-reactive protein-albumin ratio (CAR) has been demonstrated to be associated with poor prognosis in patients with various cancers. Although the relatively low cell dose of a single cord blood unit restricts the indication for cord blood transplantation (CBT) to pediatric and relatively smaller and lighter adult patients, the impact of malnutrition on outcomes after CBT is unclear. We retrospectively analyzed 165 adult patients who underwent myeloablative single-unit CBT in our institute. In multivariate analysis, a higher CONUT score, which is indicative of poor inflammatory and nutritional status, was significantly associated with poor outcomes, including low neutrophil engraftment and development of extensive chronic graft-versus-host disease. A higher CAR, which is also suggestive of poor inflammatory and nutritional status, was significantly associated with poor neutrophil engraftment and higher overall mortality. Body mass index (BMI) was not associated with transplantation outcomes. These data suggest that poor pretransplantation inflammatory and nutritional status might be a more practical parameter than lower BMI, for predicting transplantation outcomes after single CBT for adults.


Asunto(s)
Trasplante de Células Madre de Sangre del Cordón Umbilical/métodos , Inflamación/diagnóstico , Neoplasias/diagnóstico , Estado Nutricional , Adulto , Biomarcadores/análisis , Índice de Masa Corporal , Proteína C-Reactiva/análisis , Trasplante de Células Madre de Sangre del Cordón Umbilical/normas , Humanos , Agonistas Mieloablativos/uso terapéutico , Neoplasias/terapia , Pronóstico , Estudios Retrospectivos , Albúmina Sérica Humana/análisis , Adulto Joven
5.
Surg Innov ; 26(4): 432-435, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30734640

RESUMEN

The use of surgical treatment for refractory isolated gastric varices has decreased owing to the development of endoscopic and radiologic procedures, although surgeries are sometimes required as the final method. A 75-year-old Japanese woman was diagnosed with solitary gastric varices. Initially, intraoperative splenic artery embolization was performed using the balloon transcatheter technique under general anesthesia. Laparoscopic splenectomy was performed safely owing to preoperative splenic artery embolization. Intraoperative indocyanine green (ICG) fluorescence angiography was performed following the injection of 5 mL of ICG; the remnant stomach was observed using laparoscopic equipment with an ICG imaging system, and blood flow from the remnant gastric artery was confirmed. The blood did not pool or wash out immediately, which confirmed successful devascularization of the stomach. The total operative time was 269 minutes, and the intraoperative blood loss was 500 mL. The patient's postoperative course was good, and at 21 days after the last operation, she was discharged from our hospital in remission. Real-time fluorescence angiography with ICG is a reliable and objective technique of assessing blood flow of the stomach. Accurate, extensive devascularization in the lower esophagus and upper stomach was performed using Hassab's procedure in combination with ICG imaging.


Asunto(s)
Várices Esofágicas y Gástricas/cirugía , Laparoscopía/métodos , Esplenectomía/métodos , Estómago/cirugía , Anciano , Embolización Terapéutica , Endoscopía Gastrointestinal , Várices Esofágicas y Gástricas/diagnóstico por imagen , Femenino , Angiografía con Fluoresceína , Humanos , Verde de Indocianina , Estómago/irrigación sanguínea , Estómago/diagnóstico por imagen
6.
Nihon Shokakibyo Gakkai Zasshi ; 116(10): 826-832, 2019.
Artículo en Japonés | MEDLINE | ID: mdl-31597881

RESUMEN

A 75-year-old woman presented complaining of anorexia. A malignant gastrointestinal lymphoma was diagnosed, and chemotherapy was initiated. After 2 months, she developed vomiting. Computed tomography (CT) revealed thickening of the jejunal wall and dilatation of the intestine proximal to that area. Positron emission tomography-CT showed no uptake. Small bowel stenosis due to cicatricial stenosis after chemotherapy was suspected. Laparoscopic partial resection of the stenotic small bowel segment was performed. Histopathologically, only granulation tissue was seen with no evidence of tumor. Occasionally, cicatricial stenosis can develop after chemotherapy for malignant gastrointestinal lymphoma. Therefore, this condition must be considered an important complication of treatment for this disease.


Asunto(s)
Obstrucción Intestinal , Neoplasias del Yeyuno , Linfoma , Anciano , Constricción Patológica , Femenino , Humanos , Tomografía Computarizada por Tomografía de Emisión de Positrones
7.
J Gen Intern Med ; 33(3): 384-387, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29188542

RESUMEN

Wet beriberi, characterized by high cardiac output with predominantly right-sided heart failure and lactic acidosis, is a disease caused by thiamine deficiency, and is rarely seen in modern society. However, patients with social withdrawal syndrome, also known as hikikomori syndrome, may be a new population at risk of thiamine deficiency. Hikikomori syndrome, first recognized in Japan, is becoming a worldwide issue. A 39-year-old Japanese patient was brought to our hospital, with a 3-week history of progressive shortness of breath and generalized edema. The patient had right-sided high-output heart failure, lactic acidosis, and Wernicke-Korsakoff syndrome. Because of his history of social isolation, we diagnosed hikikomori syndrome according to the Japanese government's definition, which is as follows: lifestyle centered at home; no interest or willingness to attend school or work; persistence of symptoms beyond 6 months; and exclusion of other psychiatric and developmental disorders. Considering his diagnosis of hikikomori syndrome and social isolation, we suspected malnutrition, particularly thiamine deficiency, and successfully treated him. Clinicians should be aware of the potential risk of thiamine deficiency associated with hikikomori syndrome and initiate thiamine replacement in cases of high-output heart failure associated with lactic acidosis.


Asunto(s)
Beriberi/diagnóstico por imagen , Insuficiencia Cardíaca/diagnóstico por imagen , Síndrome de Korsakoff/diagnóstico por imagen , Aislamiento Social , Deficiencia de Tiamina/diagnóstico por imagen , Adulto , Beriberi/tratamiento farmacológico , Beriberi/psicología , Insuficiencia Cardíaca/tratamiento farmacológico , Insuficiencia Cardíaca/psicología , Humanos , Relaciones Interpersonales , Síndrome de Korsakoff/tratamiento farmacológico , Síndrome de Korsakoff/psicología , Masculino , Aislamiento Social/psicología , Síndrome , Deficiencia de Tiamina/tratamiento farmacológico , Deficiencia de Tiamina/psicología , Complejo Vitamínico B/administración & dosificación
8.
Nihon Shokakibyo Gakkai Zasshi ; 115(1): 101-107, 2018.
Artículo en Japonés | MEDLINE | ID: mdl-29353846

RESUMEN

Here, we report a case of adult gastric volvulus that was treated using an upper gastrointestinal series and provide a review of relevant reports. A 55-year-old woman presented with upper abdominal pain. Abdominal computed tomography revealed mesenteroaxial gastric volvulus. We performed an upper gastrointestinal series after the placement of a nasogastric tube. We successfully performed detorsion by repositioning. There was no recurrence of gastric volvulus after the detorsion. However, considering the risk of recurrence, we also performed laparoscopic gastropexy. The postoperative course was uneventful, and she was discharged from the hospital on postoperative day 3. No recurrence of symptoms has been observed to date.


Asunto(s)
Vólvulo Gástrico/diagnóstico , Dolor Abdominal , Adulto , Endoscopía , Femenino , Humanos , Intubación Gastrointestinal , Persona de Mediana Edad , Vólvulo Gástrico/terapia , Tomografía Computarizada por Rayos X
9.
Nihon Shokakibyo Gakkai Zasshi ; 112(1): 101-7, 2015 Jan.
Artículo en Japonés | MEDLINE | ID: mdl-25744926

RESUMEN

A 68-year-old woman presented with general malaise. Her vital signs were unstable, and abdominal computed tomography revealed giant (10 cm) splenic artery aneurysm with evidence of rupture. We first occluded the root of the splenic artery using a balloon catheter. Next, we resected the distal pancreas and spleen because of the aneurysm size and destruction of the related vasculature. After surgery, the patient's condition improved, and she was discharged from the hospital on postoperative day 18. Because ruptured giant splenic artery aneurysms are very rare, we report this case with a review of the literature.


Asunto(s)
Aneurisma Roto/cirugía , Arteria Esplénica/cirugía , Anciano , Femenino , Humanos , Imagenología Tridimensional , Tomografía Computarizada por Rayos X , Resultado del Tratamiento
10.
Appl Radiat Isot ; 204: 111084, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38016258

RESUMEN

High sensitivity and high resolution is desired in such technologies as neutron radiography. However, the contamination of gamma photons in neutron images decreases the accuracy of neutron radiography. To solve this problem, we developed an event-by-event based neutron imaging system that can selectively detect neutrons. The developed neutron imaging system consists of an Li-ZnS(Ag) scintillator plate optically coupled to a flat panel photomultiplier tube (FP-PMT) with a light guide. Scintillation light emitted from the Li-ZnS(Ag) by the interaction with neutron-induced particles is used to calculate the position based on the center of mass calculations. The spatial resolution of the neutron imaging detector is ∼2.3 mm FWHM, and the sensitivity for 252Cf at 2 cm from the source with 2-cm-thick polystyrene is 20 cps/MBq. Background count fraction from 60Co gamma photons was 0.2 %. For various types of neutron absorption phantoms, high-contrast and high-resolution neutron images are obtained with the developed neutron imaging detector using a252Cf neutron source.

11.
Sci Rep ; 14(1): 13494, 2024 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-38866842

RESUMEN

In the realm of radiation therapy, a conspicuous obstacle lies in the dearth of external observation concerning radiation beams aimed at the patient. While real-time monitoring of such beams on the patient's surface during therapy holds promise, the imaging of particle beams has thus far proven to be a formidable task. Here, we show our discovery of polyester fabrics and cloths as auspicious scintillating materials, ideally suited for the visualization of radiation beams upon the patient's surface. The light output of polyester fabrics ranged from 10 to 20% of that observed in plastic scintillators. When exposed to spot scanning proton beams, clear beam spots emerged on the surface of the polyester cloths. The movement of these scanning beams was effectively captured using a CMOS camera in a light-shield-free with lights-off environment. The resulting images provided a means for evaluating spills of the proton beams. The inherent flexibility of polyester fabrics and clothing enhances their appeal for applications in the intricate landscape of radiation therapy, promising a bright future for surface beam imaging endeavors.

12.
Sci Rep ; 14(1): 14504, 2024 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-38914610

RESUMEN

This research aimed to identify materials capable of emitting visible light useful for dose management at ultra-high dose rate (uHDR). Various materials were irradiated with proton beams at a normal dose rate (NDR) and uHDR, and the resulting surface luminescence was captured using a high-sensitivity camera. The luminescence images were compared with the corresponding dose distributions. The luminescence of Tough Water Phantoms (Kyoto Kagaku Co. Ltd.) with various thicknesses was also observed to evaluate the depth distributions. Dose distributions were measured using two-dimensional ionization chamber detector arrays. The Tough Bone Phantom (Kyoto Kagaku Co. Ltd.) exhibited the strongest luminescence among the materials, followed by the Tough Water Phantom. The metals exhibited relatively weak luminescence. The luminescence profiles of the Tough Water Phantom, water, the Tough Lung Phantom (Kyoto Kagaku Co. Ltd.), and an acrylic were similar to the dose profiles. The luminescence distribution of the Tough Water Phantom in the depth direction was similar to that of the dose distributions. The luminescence at uHDR and NDR were approximately equivalent. The Tough Water Phantom was found to be a suitable material for dosimetry, even at uHDR. More detailed measurement data, such as wavelength data, must be collected to elucidate the luminescence mechanism.

13.
RSC Adv ; 14(14): 9509-9513, 2024 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-38516151

RESUMEN

We elucidate the decomposition mechanism of hydrogen peroxide, which is formed by water radiolysis, by gold nanoparticles (GNPs) under X-ray irradiation. The variations in yields of hydrogen peroxide generated in the presence of GNPs are evaluated using the Ghormley technique. The increase of yields of OH radicals has been quantified using Ampliflu® Red solutions. Almost all hydrogen peroxide generated by irradiation of <25 Gy is decomposed by GNPs, while the yield of OH radicals increases by 1.6 times. The amount of OH radicals thus obtained is almost equivalent to that of the decomposed hydrogen peroxide. The decomposition of hydrogen peroxide is an essential reaction to produce additional OH radicals efficiently in the vicinity of GNPs.

14.
Appl Radiat Isot ; 204: 111143, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38101006

RESUMEN

High-resolution and real-time imaging of particle ion trajectories is essential in nuclear medicine and nuclear engineering. One potential method to achieve high-resolution real-time trajectory imaging of particle ions involves utilizing an imaging system that integrates a scintillator plate with a magnifying unit and a cooled electron multiplying charge-coupled device (EM-CCD) camera. However, acquiring an EM-CCD camera might prove challenging due to the discontinuation of CCD sensor manufacturing by vendors. As an alternative imaging approach, a low-noise, high-sensitivity camera utilizing a cooled complementary metal-oxide-semiconductor (CMOS) sensor offers a promising solution for imaging particle ion trajectories. Yet, it remains uncertain whether CMOS-based cameras can perform as effectively as CCD-based cameras in capturing particle ion trajectories. To address these concerns, we conducted a comparative analysis of the imaging performance between a CMOS-based system and an EM-CCD-based system for capturing alpha particle trajectories. The results revealed that both systems could image the trajectories of alpha particle, but the spatial resolution with the CMOS-based camera exceeded that of the EM-CCD-based camera, primarily due to the smaller pixel size of the sensor. While the signal-to-noise ratio (SNR) of the trajectory image from the CMOS-based camera initially lagged behind that from the EM-CCD-based camera, this disparity was mitigated by implementing binning techniques on the CMOS-based camera images. In conclusion, our findings suggest that a cooled CMOS camera could serve as a viable alternative for imaging particle ion trajectories.

15.
Phys Med Biol ; 69(5)2024 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-38385258

RESUMEN

Objective. Prompt gamma photon, prompt x-ray, and induced positron imaging are possible methods for observing a proton beam's shape from outside the subject. However, since these three types of images have not been measured simultaneously nor compared using the same subject, their advantages and disadvantages remain unknown for imaging beam shapes in therapy. To clarify these points, we developed a triple-imaging-modality system to simultaneously measure prompt gamma photons, prompt x-rays, and induced positrons during proton beam irradiation to a phantom.Approach. The developed triple-imaging-modality system consists of a gamma camera, an x-ray camera, and a dual-head positron emission tomography (PET) system. During 80 MeV proton beam irradiation to a polymethyl methacrylate (PMMA) phantom, imaging of prompt gamma photons was conducted by the developed gamma camera from one side of the phantom. Imaging of prompt x-rays was conducted by the developed x-ray camera from the other side. Induced positrons were measured by the developed dual-head PET system set on the upper and lower sides of the phantom.Main results. With the proposed triple-imaging-modality system, we could simultaneously image the prompt gamma photons and prompt x-rays during proton beam irradiation. Induced positron distributions could be measured after the irradiation by the PET system and the gamma camera. Among these imaging modalities, image quality was the best for the induced positrons measured by PET. The estimated ranges were actually similar to those imaged with prompt gamma photons, prompt x-rays and induced positrons measured by PET.Significance. The developed triple-imaging-modality system made possible to simultaneously measure the three different beam images. The system will contribute to increasing the data available for imaging in therapy and will contribute to better estimating the shapes or ranges of proton beam.


Asunto(s)
Terapia de Protones , Protones , Rayos X , Electrones , Terapia de Protones/métodos , Tomografía Computarizada por Rayos X , Fotones/uso terapéutico , Rayos gamma , Fantasmas de Imagen , Método de Montecarlo
16.
Front Med (Lausanne) ; 10: 1038348, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37521357

RESUMEN

Recently, in-beam positron emission tomography (PET) has been actively researched for reducing biological washout effects and dose monitoring during irradiation. However, the positron distribution does not precisely reflect the dose distribution since positron production and ionization are completely different physical processes. Thus, a novel in-beam system was proposed to determine proton dose range by measuring scattered protons with dozens of scintillation detectors surrounding the body surface. While previous studies conducted a preliminary experiment with a simple phantom, we simulated more complex situations in this paper. Especially, we conducted three stepwise simulation studies to demonstrate the feasibility of the proposed method. First, a simple rectangular phantom was reproduced on simulation and irradiated with protons for obtaining current values and Monte Carlo (MC) dose. Next, we trained a deep learning model to estimate 2-dimensional-dose range (2D-DL dose) from measured current values for simulation (A). We simulated plastic scintillators as detectors to measure the scattered protons. Second, a rectangular phantom with an air layer was used, and 3D-DL dose was estimated in simulation (B). Finally, a cylindrical phantom that mimics the human body was used for confirming the estimation quality of the simulation (C). Consequently, the position of the Bragg peak was estimated with an error of 1.0 mm in simulation (A). In addition, the position of the air layer, as well as the verifying peak position with an error of 2.1 mm, was successfully estimated in simulation (B). Although the estimation error of the peak position was 12.6 mm in simulation (C), the quality was successfully further improved to 9.3 mm by incorporating the mass density distribution obtained from the computed tomography (CT). These simulation results demonstrated the potential of the as-proposed verification system. Additionally, the effectiveness of CT utilization for estimating the DL dose was also indicated.

17.
Sci Rep ; 13(1): 4955, 2023 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-37100780

RESUMEN

High-resolution imaging of alpha particles is required in the detection of alpha radionuclides in cells or small organs for the development of radio-compounds for targeted alpha-particle therapy or other purposes. We developed an ultrahigh resolution, real time alpha-particle imaging system for observing the trajectories of alpha particles in a scintillator. The developed system is based on a magnifying unit and a cooled electron multiplying charge-coupled device (EM-CCD) camera, combined with a 100-µm-thick Ce-doped Gd3Al2Ga3O12 (GAGG) scintillator plate. Alpha particles from an Am-241 source were irradiated to the GAGG scintillator and imaged with the system. Using our system, we measured the trajectories of the alpha particles having different shapes in real time. In some of these measured trajectories, the line shapes of the alpha particles that flew in the GAGG scintillator were clearly observed. The lateral profiles of the alpha-particle trajectories were imaged with widths of ~ 2 µm. We conclude that the developed imaging system is promising for research on targeted alpha-particle therapy or other alpha particle detections that require high spatial resolution.

18.
Phys Med ; 109: 102592, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37084677

RESUMEN

Prompt secondary electron bremsstrahlung X-ray (prompt X-ray) imaging using a low-energy X-ray camera is a promising method for observing a beam shape from outside the subject. However, such imaging has so far been conducted only for pencil beams without a multi-leaf collimator (MLC). The use of spread-out Bragg peak (SOBP) with an MLC may increase the scattered prompt gamma photons and decrease the contrast of the images of prompt X-rays. Consequently, we performed prompt X-ray imaging of SOBP beams formed with an MLC. This imaging was carried out in list mode during irradiation of SOBP beams to a water phantom. An X-ray camera with a 1.5-mm diameter as well as 4-mm-diameter pinhole collimators was used for the imaging. List mode data were sorted to obtain the SOBP beam images as well as energy spectra and time count rate curves. Due to the high background counts from the scattered prompt gamma photons penetrating the tungsten shield of the X-ray camera, the SOBP beam shapes were difficult to observe with a 1.5-mm-diameter pinhole collimator. With the 4-mm-diameter pinhole collimators, images of SOBP beam shapes at clinical dose levels could be obtained with the X-ray camera. The use of a 4-mm-diameter pinhole collimator attached to the X-ray camera is effective for prompt X-ray imaging with high sensitivity and low background counts. This approach makes it possible to image SOBP beams with an MLC when the counts are low and the background levels are high.


Asunto(s)
Carbono , Rayos X , Radiografía , Fantasmas de Imagen , Iones
19.
Intern Med ; 2023 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-37866918

RESUMEN

Osmotic demyelination syndrome (ODS) occurs in patients with diabetes and hyponatremia. We herein report a case of ODS with chorea detected on serial magnetic resonance imaging (MRI), despite no prompt hyponatremia correction. A 74-year-old man with cirrhosis and uncontrolled type 2 diabetes developed an altered mental status and chorea during treatment for diabetic ketoacidosis (DKA). Despite no rapid sodium correction and normal initial brain MRI findings, serial MRI revealed ODS-related abnormalities. Clinicians should consider ODS in patients with DKA and a hyperosmolar hyperglycemic state displaying unconsciousness and neurological manifestations, including chorea, even without substantial changes in serum sodium levels. An MRI re-examination can help capture missing ODS complications.

20.
Biomed Phys Eng Express ; 10(1)2023 11 23.
Artículo en Inglés | MEDLINE | ID: mdl-37948761

RESUMEN

Objective. Precise monitoring of the position and dwell time of iridium-192 (Ir-192) during high-dose-rate (HDR) brachytherapy is crucial to avoid serious damage to normal tissues. Source imaging using a compact gamma camera is a potential approach for monitoring. However, images from the gamma camera are affected by blurring and statistical noise, which impact the accuracy of source position monitoring. This study aimed to develop a deep-learning approach for estimating ideal source images that reduce the effect of blurring and statistical noise from experimental images captured using a compact gamma camera.Approach. A double pix2pix model was trained using the simulated gamma camera images of an Ir-192 source. The first model was responsible for denoising the Ir-192 images, whereas the second model performed super resolution. Trained models were then applied to the experimental images to estimate the ideal images.Main results. At a distance of 100 mm between the compact gamma camera and the Ir-192 source, the difference in full width at half maximum (FWHM) between the estimated and actual source sizes was approximately 0.5 mm for a measurement time of 1.5 s. This difference has been improved from approximately 2.7 mm without the use of DL. Even with a measurement time of 0.1 s, the ideal images could be estimated as accurately as in the 1.5 s measurements. This method consistently achieved accurate estimations of the source images at any position within the field of view; however, the difference increased with the distance between the Ir-192 source and the compact gamma camera.Significance. The proposed method successfully provided estimated images from the experimental images within errors smaller than 0.5 mm at 100 mm. This method is promising for reducing blurring and statistical noise from the experimental images, enabling precise real-time monitoring of Ir-192 sources during HDR brachytherapy.


Asunto(s)
Braquiterapia , Aprendizaje Profundo , Radioisótopos de Iridio , Braquiterapia/métodos , Cámaras gamma
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