scholarly journals Determination of Gallstone Composition using Dual-Energy Computed Tomography: An Ex-vivo Study

2021 ◽  
Vol 5 (1) ◽  
pp. 42-52
Author(s):  
Seonghyun Wee ◽  
Young Hwan Lee ◽  
Youe Ree Kim ◽  
Kwon Ha Yoon ◽  
Dong-Eun Park
Keyword(s):  
Computed Tomography ◽  
Ftir Spectroscopy ◽  
Ex Vivo ◽  
Cholesterol Gallstones ◽  
High Attenuation ◽  
Pigment Gallstones ◽  
Quantitative Analyses ◽  
Image Set ◽  
Calculous Cholecystitis ◽  
Attenuation Values

Purpose: This study aimed to investigate whether ex-vivo gallstones are distinguishable by type using dualenergy computed tomography (DECT).Materials and Methods: A total of 124 gallstones from 65 patients with acute or chronic calculous cholecystitis were evaluated using DECT. The extracted gallstones were submerged in distilled water in an acrylic container and scanned at tube voltages of 80/140 kVp and 100/140 kVp. The images were grouped into three sets: 80, 100, and 140 kVp. Qualitative analyses of DECT sensitivity and attenuation patterns in each image set were performed, and quantitative analyses included calculation of mean attenuation values and measurement of the gallstone size. Semi-quantitative Fourier transform infrared (FTIR) spectroscopy was used as the reference standard to confirm the chemical composition of the gallstones.Results: FTIR spectroscopy identified 66 gallstones from 33 patients as cholesterol gallstones and 58 gallstones from 32 patients as pigment gallstones. Qualitative analysis indicated that DECT sensitivity for cholesterol gallstones was greatest at 80 kVp. Most cholesterol gallstones (79%) showed low attenuation at 80 kVp and high attenuation (65%) at 140 kVp. Pigment gallstones demonstrated high attenuation at all image sets. On quantitative analysis, the mean calculated attenuation values of cholesterol gallstones were -17 ± 50 Hounsfield Units (HU), -5.1 ± 43 HU, and 19.2 ± 39 HU at 80, 100, and 140 kVp, respectively, and 342 ± 173 HU, 286 ± 116 HU, and 195 ± 91 HU, respectively, for pigment stones.Conclusions: Ex-vivo gallstones were distinguishable as cholesterol or pigment gallstones by using DECT.

scholarly journals Porcine Ex Vivo Liver Phantom for Dynamic Contrast-Enhanced Computed Tomography

2011 ◽  
Vol 46 (9) ◽  
pp. 586-593 ◽  
Author(s):  
Scott M. Thompson ◽  
Juan C. Ramirez-Giraldo ◽  
Bruce Knudsen ◽  
Joseph P. Grande ◽  
Jodie A. Christner ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Ex Vivo ◽  
Dynamic Contrast Enhanced ◽  
Contrast Enhanced ◽  
Enhanced Computed Tomography ◽  
Liver Phantom ◽  
Contrast Enhanced Computed Tomography

scholarly journals Comparison of the different voxel sizes in the estimation of peri-implant fenestration defects using cone beam computed tomography: an ex vivo study

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Mehmet Hakan Kurt ◽  
Nilsun Bağış ◽  
Cengiz Evli ◽  
Cemal Atakan ◽  
Kaan Orhan
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Ex Vivo ◽  
Statistical Significance ◽  
Area Under The Curve ◽  
Titanium Implant ◽  
Bone Defects ◽  
Titanium Implants ◽  
Cone Beam ◽  
Voxel Size

Abstract Background To examine the influence of voxel sizes to detect of peri-implant fenestration defects on cone beam computed tomography (CBCT) images. Materials and methods This study performed with three sheep heads both maxilla and mandible and two types of dental implant type 1 zirconium implant (Zr40) (n = 6) and type 2 titanium implant (Ti22) (n = 10). A total of 14 peri-implant fenestrations (8 buccal surfaces, 6 palatal/lingual surface) were created while 18 surfaces (8 buccal, 10 palatal/lingual) were free of fenestrations. Three observers have evaluated the images of fenestration at each site. Images obtained with 0.75 mm3, 0.100 mm3, 0.150 mm3, 0.200 mm3, and 0.400 mm3 voxel sizes. For intra- and inter-observer agreements for each voxel size, Kappa coefficients were calculated. Results Intra- and inter-observer kappa values were the highest for 0.150 mm3, and the lowest in 0.75 mm3 and 0.400 mm3 voxel sizes for all types of implants. The highest area under the curve (AUC) values were found higher for the scan mode of 0.150 mm3, whereas lower AUC values were found for the voxel size for 0.400 mm3. Titanium implants had higher AUC values than zirconium with the statistical significance for all voxel sizes (p ≤ 0.05). Conclusion A voxel size of 0.150 mm3 can be used to detect peri-implant fenestration bone defects. CBCT is the most reliable diagnostic tool for peri-implant fenestration bone defects.

scholarly journals Detection of a peritumoral pseudocapsule in patients with renal cell carcinoma undergoing robot-assisted partial nephrectomy using enhanced MDCT

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Makoto Toguchi ◽  
Toshio Takagi ◽  
Yuko Ogawa ◽  
Satoru Morita ◽  
Kazuhiko Yoshida ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Renal Cell Carcinoma ◽  
Cell Carcinoma ◽  
Partial Nephrectomy ◽  
Renal Cell ◽  
Clear Cell ◽  
Robot Assisted ◽  
High Attenuation ◽  
Papillary Rcc ◽  
Clear Cell Rcc

AbstractTo investigate the detection of peritumoral pseudocapsule (PC) using multi-detector row computed tomography (MDCT) for tumors resected by robot-assisted laparoscopic partial nephrectomy (RAPN) for T1 renal cell carcinoma (RCC). Study participants included 206 patients with clinical T1 RCC who underwent RAPN between October 2017 and February 2018. Two radiologists who were blinded to the pathological findings evaluated the computed tomography (CT) images. Radiological diagnosis of a PC was defined by a combination of observations, including a low-attenuation rim between the tumor and renal cortex in the cortico-medullary phase and a high-attenuation rim at the edge of the tumor in the nephrogenic or excretory phase. A PC was detected on CT in 156/206 tumors (76%) and identified by pathology in 182/206 (88%) tumors including 153/166 (92%) clear cell RCC, 13/14 (93%) papillary RCC, and 7/16 (44%) chromophobe RCC. In the whole cohort, CT findings showed a sensitivity of 81.3% (148/182), specificity of 66.7% (16/24), and positive predictive value of 94.9% (148/156). When the data were stratified according to pathological subtypes, MDCT was observed to have a sensitivity of 86.9% (133/153) and specificity of 61.5% (8/13) in clear cell RCC, sensitivity of 38.5% (5/13) and specificity of 100% (1/1) in papillary RCC, and sensitivity of 44.4% (4/7) and specificity of 66.7% (6/9) in chromophobe RCC. A low or high-attenuation rim around the tumor in the cortico-medullary or nephrographic-to-excretory phase indicates a PC of RCC, though the accuracy is not satisfactory even with 64- or 320-detector MDCT.

Accuracy of High-resolution Small-volume Cone-beam Computed Tomography in Detecting Complex Anatomy of the Apical Isthmi: Ex Vivo Analysis

2018 ◽  
Vol 44 (12) ◽  
pp. 1862-1866 ◽  
Author(s):  
Elen de Souza Tolentino ◽  
Pablo Andrés Amoroso-Silva ◽  
Murilo Priori Alcalde ◽  
Heitor Marques Honório ◽  
Lilian Cristina Vessoni Iwaki ◽  
...  
Keyword(s):  
Computed Tomography ◽  
High Resolution ◽  
Cone Beam Computed Tomography ◽  
Small Volume ◽  
Ex Vivo ◽  
Cone Beam ◽  
Complex Anatomy

Use of computed tomography to compare two femoral head and neck excision ostectomy techniques as performed by two novice veterinarians

2015 ◽  
Vol 28 (05) ◽  
pp. 295-300 ◽  
Author(s):  
M. D. O’Donnell ◽  
G. Bobe ◽  
R. P. Scholz ◽  
J. E. Wiest ◽  
S. Nemanic ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Femoral Head ◽  
Femoral Neck ◽  
Head And Neck ◽  
Clinical Setting ◽  
Ex Vivo ◽  
Bone Volume ◽  
Bone Trauma ◽  
Before And After ◽  
Bone Fragments

Summary Objectives: To compare the results of femoral head and neck excision (FHNE) ostectomy performed by two novice veterinarians using an osteotome and mallet or microsagittal saw. Methods: In this ex vivo cadaveric study, hindlimbs of eight canine cadavers were randomized to FHNE with osteotome or micro sagittal saw as performed by two recently graduated veterinarians. The hindimbs were imaged by computed tomography (CT) before and after the osteotomy. Post FHNE CT images were evaluated by a board certified radiologist blinded to the ostectomy technique for assessment of the number of bone fragments, fissures, smoothness of osteotomy margination, and volume of residual fe-moral neck. Results: Femoral head and neck excision performed with the osteotome produced more peri-ostectomy bone fragments, cortical fissures, irregular margins, and residual femoral neck volume, compared with osteotomy using a saw. Clinical relevance: Compared to FHNE performed with a sagittal saw, osteotome FHNE resulted in a greater bone trauma and residual neck bone volume, which would require post-ostectomy modification in a clinical setting.

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