Actual measurement verification of dose calculation accuracy based on cone-beam CT images / 中华放射肿瘤学杂志

Objective:To evaluate the dose calculation accuracy of cone-beam CT (CBCT) image by actual measurement method.Methods:CBCT images of 60 patients in the Second Affiliated Hospital of Soochow University from September, 2021 to May, 2022 were retrospectively analyzed. CBCT images of full-fan and half-fan scanning of the head, half-fan scanning of the chest and pelvis were obtained by the Varian OBI system. Hounsfield unit - electron density (HU-ED) curves corresponding to the scanning conditions were established with CIRS electron density phantom. The radiotherapy plans were designed on the CBCT images, and the dose calculation results of the detection point were compared with the ionization chamber measurement results to analyze the dose error. Then, three-dimensional dose verification system was adopted to detect the accuracy of the CBCT image radiotherapy plans implementation process in 60 patients, and the accuracy of dose calculation was verified according to the D 99%, D mean, D 1% of target volume, D mean and D 1% of organs at risk (OAR), and the γ pass rate. Results:In point dose detection in phantom, the dose calculation errors of CBCT images in the above four scanning patterns were -1.06%±0.87%、-1.67%±0.86%, 0.91%±0.73%, -1.54%±0.90%, respectively. In dosimetric verification based on patients' CBCT image treatment plan, the mean difference of D mean, D 99%, and D 1% of planning target volume (PTV) in all scanning modes were not higher than 2%, and the D mean and D 1% differences of other OAR were not higher than 3%, except for the lens of patients in the head. The average γ values of target volume and OAR were less than 0.5 under the criteria of 3%/2 mm. Conclusions:Under the condition of correctly establishing HU-ED curves, intensity-modulated radiation therapy (IMRT) / volumetric-modulated arc therapy (VMAT) planning based on CBCT images can be employed to estimate and monitor the actual dose to target volume and OAR in adaptive radiotherapy. Full-fan scanning patterns can further improve the accuracy of dose calculation for the head of patients.

Estudio de la morfología de los conductos radiculares de los primeros premolares superiores en tomografía computarizada de haz cónico / Study of the morphology of root canals of the first upper premolars in cone beam computed tomography

Objetivo: analizar, mediante tomografía computarizada de haz cónico (TC o CBCT [Cone Beam Computed Tomograph]) la frecuencia del tipo de morfología interna de los conductos radi- culares según la clasificación de Vertucci y el número de raíces de los primeros premolares superiores. Material y métodos: en una población argentina de 50 pacientes, 30 de sexo femenino y 20 masculino, que concurrieron a la Cátedra de Diagnóstico por Imá- genes de la Facultad de Odontología de la Universidad de Buenos Aires, se evaluaron 100 primeros premolares superiores con CBCT. Se estudiaron las variables: número de raíces, tipo de morfología interna, edad, sexo y lado. Fueron seleccionadas las tomografías de maxilar superior que incluyeron ambos primeros premolares en salud dental, periodontal y con ápice cerrado. Se realizó una adquisición volumétrica 100 × 90 mm y tamaño de vóxel de 150 µm. Se realizó la exploración de las imágenes en el plano axial de los tercios apical, medio y cervical de las piezas 1.4 y 2.4. Se utilizó un corte axial, observando en él, el tercio apical, medio y cervical de las piezas 1.4 y 2.4. Cada premolar fue analizado con 30 cortes transversales. Se utilizó la clasificación de Vertucci para agrupar las distintas variables anatómicas de los conductos radiculares de los primeros premolares superiores, la cual consta de VIII tipolo- gías. Resultados: el tipo más representativo entre los 100 primeros premolares superiores, dentro de la clasificación de Vertucci, fue el tipo IV (dos conductos separados desde la cámara al ápice). La coincidencia de tipos entre los lados derecho (78%; IC 95%: 65 a 87%) e izquierdo (70%; IC 95%: 56 a 81%) fue significativa. La distribución según el número de raíces en el lado derecho (χ 2 = 2.88) e izquierdo (χ2 = 0.72) no presentó una heterogeneidad significativa. La coincidencia del número de raíces entre los lados derecho e izquierdo fue significativa. Conclusión: se comprobó el tipo de morfología interna más frecuente, el número de raíces y su variabilidad de acuerdo al lado, sexo, y edad; lo cual es de una relevante importancia para realizar una correcta instrumentación y obturación del sistema de conductos radiculares (AU)

Objective: to analyze, using cone beam computed tomography (CBCT), the frequency of the type of internal morphology of the root canals according to the Vertucci classification and the number of roots of the first upper premolars. Material and methods: 100 first upper premolars were evaluated with CBCT, which corresponded to 30 female and 20 male patients in the Chair of Diagnostic Imaging of the Faculty of Dentistry, University of Buenos Aires. Variables were studied: number of roots, type of internal morphology, age, sex and side. The tomography of the upper jaw with both first premolars in dental, periodontal and closed apex health, a 100 × 90 mm volumetric acquisition and a voxel size of 150 µm were selected. An axial cut was used, observing the apical, middle and cervical third of pieces 1.4 and 2.4. Each premolar was analyzed with 30 paraxial cuts. The Vertucci classification was used to group the different anatomical variables of the root canals of the first upper premolars which consists of VIII typologies. Results: the most representative type among the top 100 upper premolars within the Vertucci classification was type IV (two separate ducts from the chamber to the apex). The type coincidence between the right (78%; 95% CI: 65 to 87%) and left (70%; 95% CI: 56 to 81%) los primeros premolares superiores, la cual consta de VIII tipolo gías. Resultados: el tipo más representativo entre los 100 primeros premolares superiores, dentro de la clasificación de Vertucci, fue el tipo IV (dos conductos separados desde la cámara al ápice). La coincidencia de tipos entre los lados derecho (78%; IC 95%: 65 a 87%) e izquierdo (70%; IC 95%: 56 a 81%) fue significativa. La distribución según el número de raíces en el lado derecho (χ 2 = 2.88) e izquierdo (χ2 = 0.72) no presentó una heterogeneidad significativa. La coincidencia del número de raíces entre los lados derecho e izquierdo fue significativa. Conclusión: se comprobó el tipo de morfología interna más frecuente, el número de raíces y su variabilidad de acuerdo al lado, sexo, y edad; lo cual es de una relevante importancia para realizar una correcta instrumentación y obturación del sistema de conductos radiculares (AU))

Ewing's Sarcoma: imaging findings of a patient with primary tumor in the femur and mandibular metastasis / Sarcoma de Ewing: achados imaginológicos de um paciente com tumor primário no femur e metástase mandibular

ABSTRACT Ewing's Sarcoma, a common primary bone malignancy that usually occurs in childhood and young adults, has a predilection for males and occurs mostly in the diaphysis of long bones and pelvis. This tumor rarely affects the head and neck. Histologically, this neoplasm is a small round cell tumor and there is evidence of a neuroectodermal origin. Radiographic findings of ES show an osteolytic lesion, that is not a pathognomonic feature for this neoplasm. The association of conventional imaging methods such radiography, Computed Tomograph (CT), magnetic resonance imaging (MRI), combined with scintigraphy or Positron Emission Tomography/ Computed tomography PET /CT), is essential for a correct diagnosis and treatment. Therefore, the aim of this report was to present image findings of a patient who presented with ES in the femur, and a metastasis in the mandible after eighteen months, and discuss the importance of imaging methods for a correct diagnosis, treatment and consequently, prognosis.

RESUMO O Sarcoma de Ewing é uma malignidade óssea primária comum que usualmente afeta crianças e adultos jovens. O Sarcoma de Ewing tem predileção por homens e acomete na maioria das vezes a diáfise dos ossos longos e a pelve. Raramente esse tumor afeta a região de cabeça e pescoço. Histologicamente essa neoplasia é composta por células redondas e há evidências de uma origem neuroectodérmica. Os Achados radiográficos do SE mostram uma lesão osteolítica que não é característica patognomonica. A associação dos métodos convencionais, como radiografia, tomografia computadorizada, ressonância magnética combinadas com cintilografia ou tomografia por emissão de positron são essenciais para o correto diagnóstico e tratamento. Desta forma,o objetivo desse trabalho é apresentar os achados imaginológicos de um paciente que apresentou Sarcoma de Ewing primário no femur e uma metástase mandibular após dezoito meses e discutir a importância dos métodos de imagem adequados para um correto diagnóstico, tratamento e consequentemente o prognóstico.

Estado perirradicular e radicular de dentes tratados endodonticamente: estudo piloto utilizando a tomografia computadorizada de feixe cônico / Periapical and root status of endodontically treated teeth: a pilot study using cone-beam computed tomograph

As imagens radiográficas periapicais, essenciais para a realização e para o acompanhamento do sucesso do tratamento endodôntico, em virtude de limitações técnicas, não são capazes de oferecer visualização anatômica de toda a estrutura dos elementos dentários. Técnicas contemporâneas de obtenção de imagens, como a tomografia computadorizada realizada pela técnica de feixe cônico (TCFC) parecem ter o potencial de avaliar de forma mais adequada a qualidade da obturação e do remanescente radicular, e o estado perirradicular. O objetivo deste trabalho foi realizar uma avaliação descritiva das imagens obtidas pela técnica de TCFC de 100 elementos dentários tratados endodonticamente, buscando os achados referentes ao estado perirradicular, as lesões de furca, à presença de núcleos intrarradiculares e as fraturas radiculares. Nos 100 dentes analisados, 83 (83%) apresentavam áreas compatíveis com a presença de alteração perirradicular. Dos dentes multirradiculares, 51% apresentavam presença de lesão de furca e 91% apresentavam rarefação perirradicular. Vinte dos 83 dentes com alterações perirradiculares (24%) apresentavam imagem sugestiva de fratura radicular. A TCFC revelou a existência de diversas alterações radiculares e perirradiculares nos dentes tratados endonticamente estudados nesta amostra, sugerindo sua utilidade no acompanhamento imaginológico após o tratamento endodôntico.

Periapical radiographs are essential for endodontic treatment and for following the tooth response after finishing the treatment. Unfortunately, due to their technical limitations, they are not capable of offering a complete anatomical view of the dental structure. More recent image techniques, such as cone-beam computed tomograph (CBCT), seem to offer a more complete picture of the pulp chamber obturation and the remaining dental structure, as well as the periradicular status. The aim of our study was to analyze CBCT images obtained from 100 endodontically treated teeth, focusing on the obturation of the pulp chamber, periapical status, interadicular alterations and root fractures. From the 100 teeth, 83 (83%) presented periradicular alterations. From multiradicular teeth, 51% presented with alterations in the interadicular area and 91% showed periradicular alterations. Twenty out 83 teeth presenting periradicular alterations (24%) showed also root fractures. CBCT images revealed the presence of several root and periradicular alterations in the endodontically treated teeth studied in this sample, suggesting its utility as an adjunctive auxiliary in the follow-up of teeth after endodontic treatment.

Comparison on application of five kinds of elastic registration methods in the CT image registration of radiotherapy / 中国医学装备

Objective: To compare the applications of five kinds of routine elastic registration methods included of Horn-Schunck optical flow method, Demons algorithm, accelerated Demons algorithm, level set algorithm and fast free deformation algorithm in radiotherapy. Methods: 10 patients who underwent radiotherapy on pelvic cavity were enrolled in the research. And their CT images at the time of location and during radiotherapy were collected, and the five kinds of routine elastic registration methods were applied in the research, and through autonomic programming to implement elastic registration, and then the registered results were further compared. Results: The average minimum mean square error (MSE) of five kinds of routine elastic registration methods have been decreased 6.7%-26.0%, and the average correlation coefficient(CC) has been increased 2.6%-3.7%, and the average registration time was 107.5s-220.8s. Conclusions: All of the five kinds of elastic registration methods get better results, and it is recommended to use Horn-Schunck optical flow method for elastic registration of radiotherapy CT. And through using elastic registration model can more accurate simulate the movement of organ, and it is a direction of further study that monitor individual dosage of organ at risk.

Angio-Computed Tomograph-Guided Immediate Lipiodol Computed Tomograph for Diagnosis of Small Hepatocellular Carcinoma Lesions during Transarterial Chemoembolization / 中华医学杂志(英文版)

<p><b>Background</b>The diagnosis and treatment of small hepatocellular carcinoma (HCC) play a vital role in the prognosis of patients with HCC. The purpose of our study was to evaluate angio-computed tomography (angio-CT)-guided immediate lipiodol CT (a CT scan performed immediately after transarterial chemoembolization [TACE]) in the diagnosis of potential HCCs ≤1 cm in diameter.</p><p><b>Methods</b>This study retrospectively analyzed 31 patients diagnosed with HCCs after routine imaging (contrast-enhanced CT or magnetic resonance imaging) or pathologic examinations with undefined or undetermined tumor lesions (diameter ≤1 cm) from February 2016 to September 2016. After TACE guided by digital subtraction angiography of the angio-CT system, potential HCC lesions with a diameter ≤1 cm were diagnosed by immediate lipiodol CT. The number of well-demarcated lesions was recorded to calculate the true positive rate. The correlation between the number of small HCCs detected by immediate lipiodol CT and the size of HCC lesions (diameter >1 cm) diagnosed preoperatively was analyzed 1 month after TACE. A paired t-test was used to analyze differences in liver function. Pearson analysis was used to analyze correlation. Chi-square test was used to compare the rates.</p><p><b>Results</b>Fifty-eight lesions were detected on preoperative routine imaging examinations in 31 patients including 15 lesions with a diameter ≤1 cm. Ninety-one lesions were detected on immediate lipiodol CT, of which 48 had a diameter ≤1 cm. After 1 month, CT showed that 45 lesions had lipiodol deposition and three lesions had lipiodol clearance. Correlation analysis showed that the number of small HCCs detected by lipiodol CT was positively correlated with the size of HCC lesions diagnosed by conventional imaging examination (R = 0.54, P < 0.05).</p><p><b>Conclusion</b>Immediate lipiodol CT may be a useful tool in the diagnosis of potential HCC lesions with a diameter of ≤1 cm.</p>

The study of cystic duct and cystic artery imaging of calculus cholecystitis with multi-slice CT / 实用放射学杂志

Objective To assess the displaying of the cystic artery and the cystic duct in calculus cholecystitis patients using MSCT.Methods One hundred and three patients with calculus cholecystitis (the experimental group)and 71 patients with non-gallbladder disease (the control group)performed the cystic artery and the cystic duct imaging using MSCT.The data in two groups were recorded and statistical analyzed.Results (1)The display rate of the cystic duct were 93.2% (96/103)in the experimental group and 100% (71/71)in the control group with the significant difference between the two groups (P 0.05).The variation rate of the cystic artery running were 13.5% (13/96)in the experimental group and 1 5.5% (1 1/71)in the control group.There was no significant difference between the groups (P >0.05).Conclusion The cystic duct and the cystic artery could be evaluted well in calculus cholecystitis using CT.The displaying of the cystic duct is relatively poor in acute cholecystitis.

Infecção orbitária: experiência no manejo de seis casos / Orbital infeccion: experience on the management of six cases

Infecções orbitárias são enfermidades, que requerem atenção e cuidados especiais. Os principais fatores etiológicos associados são sinusites paranasais e o trauma local. Essas infecções classificam-se em pré-septal e pós-septal e distinguem-se clinicamente, de acordo com a manutenção da acuidade visual e motilidade do globo ocular. O curso da infecção pode agravar com disfunção da motilidade ocular extrínseca, perda de visão e trombose do seio cavernoso. A tomografia computadorizada (TC) é o principal exame imaginológico para a classificação do abscesso, investigação etiológica, determinação da gravidade e a relação do processo com o sistema nervoso central. Este trabalho apresenta e discute o manejo de seis pacientes admitidos com infecção orbitária pelo serviço de Cirurgia e Traumatologia Bucomaxilofacial do Hospital Geral Roberto Santos e em Salvador, Bahia. A TC mostrou não haver disseminação do processo inflamatório para o sistema nervoso central em nenhum dos casos tendo esse achado sido fundamental para determinar que a conduta estivesse restrita à drenagem, sem necessidade de craniotomia. As intervenções cirúrgicas e a antibioticoterapia estavam indicadas devido à importante congestão tecidual e intensa sintomatologia dolorosa. Todos os pacientes apresentaram remissão da infecção e acuidade visual preservada... (AU)

Orbital infections are diseases that require special attention and care. The main risk factors are associated with paranasal sinusitis and local trauma. These infections are classified into pre-septal and post-septal and distinguished clinically according to the maintenance of visual acuity and eye motility. The course of the infection may worsen with extrinsic ocular motility dysfunction, loss of vision and cavernous sinus thrombosis. Computed tomography (CT) is the primary imaging examination for the classification of the abscess, etiologic investigation, determining the severity of the process and the relationship with the central nervous system. This paper presents and discusses the management of six patients admitted with orbital infection by service Oral and Maxillofacial Surgery General Hospital Roberto Santos in Salvador, Bahia. A CT scan showed no spread of the inflammatory process in the central nervous system and in any case this finding was important to determine that the drainage duct was confined without requiring craniotomy. Surgical interventions and antibiotics were given because of the important tissue congestion and intense painful symptoms. All patients had remission of infection and preserved visual acuity... (AU)

Clinical application of renal vessel angiography with 256-slice spiral CT in laparoscopic surgery for renals / 中国综合临床

Objective To investigate the clinical application of renal vessel angiography with 256-slice spiral CT in laparoscopic surgery for renals.Methods One hundred and fifty-five cases underwent computed tomograph angiography(CTA) who were all confirmed by operations.According to preoperative renal artery CTA case shown,the initial plan intraoperative renal artery was compared with the situation with the actual surgery.AIl axial images were reconstructed using technique.Results All patients underwent preoperative renal artery CTA operative findings correspond with the actual rate of 100％.CTA stereoscopic images were good at reflecting renal vascular anatomy and ectopic blood vessels line.Conclusion CTA can accurately evaluate out of shape and variation of the renal arteriesvariation.It has important significance of processing of renal arteries intraoperative rapid,dealing with the renal artery accurately and reducing blood loss or damage and other complications.

Time-dependent Changes in CT of Radiation-induced Liver Injury: A Preliminary Study in Gastric Cancer Patients / 华中科技大学学报（医学）（英德文版）

In this study, the time-dependent changes on dynamic computed tomograph (CT) of radiation-induced liver injury in gastric cancer patients was examined. The CT images of 52 gastric cancer patients who had received chemoradiotherapies were reviewed on the PACS system. Dynamic CT scan was performed in all the subjects. Our results showed that 18 patients were found to have radiation-induced liver injury. The CT findings of radiation-induced liver injury in gastric cancer patients tend to show up one month after radiation treatment. The damaged area was of low density on all three phases, and then it was enhanced on portal vein phase or delay phase. The focal radiation reaction of liver without basic disease vanished 9-11 months later after treatment. We are led to conclude that dynamic CT is of help in the diagnosis of CRT-induced liver injury, and it may be the method of choice for following up the whole course of the CRT-induced liver injury, i.e., form hepatic damage to healing. The classification of CT findings we recommend can avoid the influence of technological factors, and thereby serve as a better guide for treatment of CRT-induced liver injury.

Positional Relationship of the Mandibular Canal and Impacted Third Molars by Using Dental Cone Beam Computed Tomography

Study of Correlation Between Liver Volume and Liver Reserve Function in Posthepatitic Cirrhosis Patients / 中国普外基础与临床杂志

Objective To explore the correlation between liver volume variation of posthepatitic cirrhosis patients and the severity of the disease. Methods One hundred and eleven patients with normal livers and 74 posthepatitic cirrhosis patients underwent volume CT scan. The relation between normal liver volume and body height, body weight and body surface area was studied by linear regression and correlation method, the standard liver volume equation was deduced. The change ratio of liver volume in cirrhotic patients was calculated and compared with Child classification. Results The mean normal liver volume of Chinese adults was (1 225.15?216.23) cm~3, there was a positive correlation between liver volume and body height, body weight 〔liver volume (cm~3)=12.712?body weight (kg)+450.44〕 and body surface area 〔liver volume (cm~3)=876.02?body surface area (m~2)-297.17〕. The mean liver volume of Child A, B and C patients were (1 077.77?347.01) cm~3, (1 016.35?348.60) cm~3 and (805.73?208.85) cm~3 respectively. The liver volume and liver volume index was significantly smaller in Child C patients than those in Child A and B patients (P