Evaluation of patient-specific motion management for radiotherapy planning computed tomography using a statistical method

2022 ◽  
Author(s):  
Yoshinori Tanabe ◽  
Hidetoshi Eto
Keyword(s):  
Computed Tomography ◽  
Statistical Method ◽  
Radiotherapy Planning ◽  
Patient Specific ◽  
Motion Management

Computed Tomography-Based Patient-Specific Instrumentation Loses Accuracy with Significant Varus Preoperative Misalignment

2020 ◽  
Author(s):  
Vicente Jesús León-Muñoz ◽  
Mirian López-López ◽  
Alonso José Lisón-Almagro ◽  
Francisco Martínez-Martínez ◽  
Fernando Santonja-Medina
Keyword(s):  
Computed Tomography ◽  
Deformity Correction ◽  
Patient Specific ◽  
Control Group ◽  
X Rays ◽  
Varus Alignment ◽  
Patient Specific Instrumentation ◽  
Conventional Instrumentation ◽  
The Mean ◽  
Valgus Alignment

AbstractPatient-specific instrumentation (PSI) has been introduced to simplify and make total knee arthroplasty (TKA) surgery more precise, effective, and efficient. We performed this study to determine whether the postoperative coronal alignment is related to preoperative deformity when computed tomography (CT)-based PSI is used for TKA surgery, and how the PSI approach compares with deformity correction obtained with conventional instrumentation. We analyzed pre-and post-operative full length standing hip-knee-ankle (HKA) X-rays of the lower limb in both groups using a convention > 180 degrees for valgus alignment and < 180 degrees for varus alignment. For the PSI group, the mean (± SD) pre-operative HKA angle was 172.09 degrees varus (± 6.69 degrees) with a maximum varus alignment of 21.5 degrees (HKA 158.5) and a maximum valgus alignment of 14.0 degrees. The mean post-operative HKA was 179.43 degrees varus (± 2.32 degrees) with a maximum varus alignment of seven degrees and a maximum valgus alignment of six degrees. There has been a weak correlation among the values of the pre- and postoperative HKA angle. The adjusted odds ratio (aOR) of postoperative alignment outside the range of 180 ± 3 degrees was significantly higher with a preoperative varus misalignment of 15 degrees or more (aOR: 4.18; 95% confidence interval: 1.35–12.96; p = 0.013). In the control group (conventional instrumentation), this loss of accuracy occurs with preoperative misalignment of 10 degrees. Preoperative misalignment below 15 degrees appears to present minimal influence on postoperative alignment when a CT-based PSI system is used. The CT-based PSI tends to lose accuracy with preoperative varus misalignment over 15 degrees.

scholarly journals Development of patient specific, realistic, and reusable video assisted thoracoscopic surgery simulator using 3D printing and pediatric computed tomography images

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dayeong Hong ◽  
HaeKang Kim ◽  
Taehun Kim ◽  
Yong-Hee Kim ◽  
Namkug Kim
Keyword(s):  
Computed Tomography ◽  
Mechanical Properties ◽  
Fused Deposition Modeling ◽  
Thoracoscopic Surgery ◽  
Clinical Situation ◽  
Patient Specific ◽  
Fused Deposition ◽  
Video Assisted ◽  
Computed Tomography Images ◽  
Video Assisted Thoracoscopic Surgery

AbstractHerein, realistic and reusable phantoms for simulation of pediatric lung video-assisted thoracoscopic surgery (VATS) were proposed and evaluated. 3D-printed phantoms for VATS were designed based on chest computed tomography (CT) data of a pediatric patient with esophageal atresia and tracheoesophageal fistula. Models reflecting the patient-specific structure were fabricated based on the CT images. Appropriate reusable design, realistic mechanical properties with various material types, and 3D printers (fused deposition modeling (FDM) and PolyJet printers) were used to represent the realistic anatomical structures. As a result, the phantom printed by PolyJet reflected closer mechanical properties than those of the FDM phantom. Accuracies (mean difference ± 95 confidence interval) of phantoms by FDM and PolyJet were 0.53 ± 0.46 and 0.98 ± 0.55 mm, respectively. Phantoms were used by surgeons for VATS training, which is considered more reflective of the clinical situation than the conventional simulation phantom. In conclusion, the patient-specific, realistic, and reusable VATS phantom provides a better understanding the complex anatomical structure of a patient and could be used as an educational phantom for esophageal structure replacement in VATS.

scholarly journals Dual-Modality Imaging of Cancer with SPECT/CT

2002 ◽  
Vol 1 (6) ◽  
pp. 449-458 ◽  
Author(s):  
Bruce H. Hasegawa ◽  
Kenneth H. Wong ◽  
Koji Iwata ◽  
William C. Barber ◽  
Andrew B. Hwang ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Em Algorithm ◽  
Photon Emission ◽  
Imaging Systems ◽  
Patient Specific ◽  
Emission Computed Tomography ◽  
Functional Information ◽  
Dual Modality ◽  
Photon Attenuation ◽  
Dual Modality Imaging

Dual-modality imaging is an in vivo diagnostic technique that obtains structural and functional information directly from patient studies in a way that cannot be achieved with separate imaging systems alone. Dual-modality imaging systems are configured by combining computed tomography (CT) with radionuclide imaging (using positron emission tomography (PET) or single-photon emission computed tomography (SPECT)) on a single gantry which allows both functional and structural imaging to be performed during a single imaging session without having the patient leave the imaging system. A SPECT/CT system developed at UCSF is being used in a study to determine if dual-modality imaging offers advantages for assessment of patients with prostate cancer using111 In-ProstaScint®, a radiolabeled antibody for the prostate-specific membrane antigen.111 In-ProstaScint® images are reconstructed using an iterative maximum-likelihood expectation-maximization (ML-EM) algorithm with correction for photon attenuation using a patient-specific map of attenuation coefficients derived from CT. The ML-EM algorithm accounts for the dual-photon nature of the111 In-labeled radionuclide, and incorporates correction for the geometric response of the radionuclide collimator. The radionuclide image then can be coregistered and overlaid in color on a grayscale CT image for improved localization of the functional information from SPECT. Radionuclide images obtained with SPECT/CT and reconstructed using ML-EM with correction for photon attenuation and collimator response improve image quality in comparison to conventional radionuclide images obtained with filtered backprojection reconstruction. These results illustrate the potential advantages of dual-modality imaging for improving the quality and the localization of radionuclide uptake for staging disease, planning treatment, and monitoring therapeutic response in patients with cancer.

scholarly journals Age- and sex-related changes of the volume of maxillary sinuses quantified via cone beam computed tomography

2021 ◽  
Vol 10 (14) ◽  
pp. e312101422220
Author(s):  
Lucas Eigi Borges Tanaka ◽  
Ademir Franco ◽  
Rafael Ferreira Abib ◽  
Luiz Roberto Coutinho Manhães-Junior ◽  
Sergio Lucio Pereira de Castro Lopes
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Three Dimensional ◽  
Specific Treatment ◽  
Cone Beam ◽  
Patient Specific ◽  
Sample Collection ◽  
Left And Right ◽  
Age And Sex ◽  
Maxillary Sinuses

Anatomical studies found in cone beam computed tomography (CBCT) an optimal resource for the three-dimensional (3D) assessment of the head and neck. When it comes to the maxillary sinuses, CBCT enables a life-size reliable volumetric analysis. This study aimed to assess the age and sex-related changes of the maxillary sinuses using volumetric CBCT analysis. The sample consisted of CBCT scans of 112 male (n = 57) and female (n = 55) individuals (224 maxillary sinuses) distributed in 5 age categories: 20 |— 30, 31 |— 40, 41 |— 50, 51 |— 60 and > 60 years. Image acquisition was accomplished with the i-CAT Next Generation device set with voxel size of 0.25 mm and field of view that included the maxillary sinuses (retrospective sample collection from an existing database). Image segmentation was performed in itk-SNAP (www.itksnap.org) software. The volume (mm3) of the segmented sinuses was quantified and compared pairwise based on side (left and right), sex (male and female) and age (five groups). Differences between left and right sides volume were not statistically significant (p > 0.05). The mean volume of maxillary sinuses in males was 22% higher than females (p = 0.0001). Volumetric differences were not statistically significant between age categories for males and females (p > 0.05). The discriminant power of sinuses’ volume may support customized and patient-specific treatment planning based on sex.

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