SU-FF-J-27: Novel 4D CT Scanning Protocol Using a Helical Single-Slice CT Scanner

2005 ◽  
Vol 32 (6Part4) ◽  
pp. 1925-1925
Author(s):  
G Stroian ◽  
E Heath ◽  
L Collins ◽  
J Seuntjens
Keyword(s):  
Ct Scanning ◽  
Ct Scanner ◽  
4D Ct ◽  
Scanning Protocol ◽  
Single Slice

scholarly journals Optimization of Dose Parameters to Patients Undergoing CT Scan Using Four Different CT Scanners with International Guidelines

2017 ◽  
pp. 197-203
Author(s):  
Issahaku Shirazu ◽  
Y. B Mensah ◽  
Cyril Schandorf ◽  
S. Y. Mensah ◽  
Alfred Owusu
Keyword(s):  
Ct Scan ◽  
Medical Diagnosis ◽  
Image Data ◽  
Ct Scanning ◽  
Radiation Doses ◽  
Ct Scanner ◽  
Additional Source ◽  
Scanning Protocol ◽  
Ct Scanners ◽  
Radiological Procedures

Although the use of CT in medical diagnosis delivers radiation doses to patients that are higher than those from other radiological procedures, lack of proper optimized protocols could be an additional source of increased dose in developing countries. The aims of this study is to determine the variations of doses to patients undergoing CT scan using four different CT scanners with different CT scanning protocols for the purposes of optimizations and to compare with other available international standard and guidelines. The method involve the use of patients scanning protocol and image data to estimate patient body regional doses with four common CT examinations. These were obtained from four CT units/hospitals in Ghana. A large variation of mean body regional doses among different CT scanners were observed for similar CT examinations. These variations largely originated from different CT scanning protocols used, with different CT scanner type. The measured CTDIVOL with GE Lightspeed VCT 64 scanner for head, hest, abdomen and pelvis were 7.7mGy, 12.5 mGy, 14.4 mGy, and 12.9 mGy, respectively. Similarly, Philip 16 scanner recorded 6.6mGy, 13.1mGy, 14.8mGy, and 14.5mGy respectively. Furthermore, Siemen Emotion 16 scanner recorded 5.9mGy, 14.2mGy, 16.8mGy and 12.0mGy respectively. While, Toshiba Aquilion one scanner had CTDIVOL value which varies as 7.2mGy, 13.4mGy, 15.2mGy and 13.5mGy respectively. In conclusion the values were mostly lower than the values of CTDI and DLP as reported in literature for EC, IAEA, ICRP, ACR and AAPM Guidelines.

Development and performance evaluation of the first model of 4D CT-scanner

2002 ◽  
pp. 372-376 ◽  
Author(s):  
Masahiro Endo ◽  
Takanori Tsunoo ◽  
Susumu Kandatsu ◽  
Shuzi Tanada ◽  
Hiroshi Aradate ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Ct Scanner ◽  
4D Ct ◽  
And Performance

scholarly journals Time-Enhancement Curve of Four-Dimensional Computed Tomography Predicts Aneurysm Enlargement with Type-II Endoleak after Endovascular Aneurysm Repair

Aorta ◽  
2020 ◽  
Vol 08 (02) ◽  
pp. 029-034
Author(s):  
Yunosuke Nishihara ◽  
Kota Mitsui ◽  
Shinya Azama ◽  
Daisuke Okamoto ◽  
Manabu Sato ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Equilibrium Phase ◽  
Endovascular Aneurysm Repair ◽  
Three Dimensional ◽  
Type Ii ◽  
Ct Scanner ◽  
Stable Group ◽  
Ct Number ◽  
4D Ct ◽  
Aneurysm Repair

Abstract Objective We investigated the hemodynamic features of Type-II endoleaks after endovascular aneurysm repair (EVAR) using four-dimensional (4D) computed tomography (CT) to identify patients with aneurysm enlargement. Methods During a 13-month period (January 2017–January 2018) at our institution, we performed 4D-CT examinations in 13 patients after EVAR because of suspected Type-II endoleaks. Three patients were excluded from the study because of other endoleaks or absence of detectable endoleaks. The ramaining 10 patients were divided into two groups: enlargement group (n = 4), in which the aneurysm volume increased, and stable group (n = 6), in which the aneurysm remained stable or shrank. A CT scanner and three-dimensional workstation were used. All images were obtained using a consistent protocol (22 phase scans using the test bolus tracking method). We analyzed the hemodynamics of the endoleak cavity (EC) relative to those of the aorta and evaluated the time-enhancement curves (TECs) using measurement protocols. The strengths of correlations between these factors in the two groups were analyzed statistically. Results TECs in the enlargement group showed a more gradual curve, and the upslope, the gradient of TEC in the ascending phase and the upslope index were significantly more gradual than those in the stable group (p = 0.0247, 0.0243). The EC washout and the EC washout index were also more gradual than in the stable group's (p = 0.019, 0.019). The enhancement duration was longer in the former than in the latter (80%, p = 0.0195; 70%, p = 0.0159; 60%, p = 0.0159). The CT number in the equilibrium phase was larger in the enlargement group than in the stable group (p = 0.019). Conclusion The 4D-CT is useful for predicting aneurysm enlargement with Type-II endoleaks after EVAR.

scholarly journals CT lymphography for sentinel lymph node mapping of clinically N0 early oral cancer

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Satomi Sugiyama ◽  
Toshinori Iwai ◽  
Toshiharu Izumi ◽  
Keita Ishiguro ◽  
Junichi Baba ◽  
...  
Keyword(s):  
Lymph Node ◽  
Sentinel Lymph Node ◽  
Oral Cancer ◽  
Lymph Nodes ◽  
Contrast Medium ◽  
Sentinel Lymph Node Mapping ◽  
Ct Scanning ◽  
Optimal Timing ◽  
Ct Scanner ◽  
Lymph Node Mapping

Abstract Background The objectives of this retrospective study were to evaluate the usefulness of computed tomography lymphography (CTL) and to clarify the optimal timing of CTL in sentinel lymph node (SLN) mapping of clinically N0 early oral cancer. Methods Twenty patients with clinically N0 early oral cancer underwent CTL with a 128 multi-detector row CT scanner to detect SLN the day before resection of primary tumor and SLN biopsy with indocyanine green (ICG) fluorescence guidance. CT scanning was performed in the first 10 patients at 2, 5, and 10 min after submucosal injection of iopamidol and in the remaining 10 patients at 2, 3.5, 5, and 10 min after the injection of contrast medium. We evaluated the SLN detection rate at each scan timing and the number and location of SLNs. We evaluated whether CTL-enhanced SLNs could be identified intraoperatively as ICG fluorescent lymph nodes. Results SLNs were detected by CTL in 19 of the 20 patients (95.0%), and the mean number of SLNs was 2 (range, 1–4). All SLNs were located on the ipsilateral side; 35 of 37 SLNs were located at level I and II, and 2 SLNs were lingual lymph nodes. All SLNs could be detected 2 min and 3.5–5 min after contrast medium injection, and CTL-enhanced SLNs could be identified intraoperatively as fluorescent lymph nodes. Conclusions CTL could facilitate the detection of SLNs in early oral cancer, and the optimal timing of CT scanning was at 2 and 5 min after injection of contrast medium.

Urodynamic 4D-CT evaluation: 320-row area detector CT scanner combined with PhyZiodynamics software analysis provides an innovative system to evaluate urinary flow and outlet obstructions

2019 ◽  
Vol 61 (4) ◽  
pp. 558-567
Author(s):  
Shintaro Mori ◽  
Hideki Yashiro ◽  
Masanori Inoue ◽  
Kiyoshi Takahara ◽  
Mamoru Kusaka ◽  
...  
Keyword(s):  
Urinary Tract ◽  
Lower Urinary Tract ◽  
Urinary Tract Obstruction ◽  
Urinary Flow ◽  
Ct Scanner ◽  
4D Ct ◽  
Software Analysis ◽  
Area Detector ◽  
Lower Urinary Tract Obstruction ◽  
Lower Urinary

Background Evaluation of the morphology of the lower urinary tract as well as the movements associated with urination are required for the symptomatic diagnosis of lower urinary tract obstruction as well as the assessment of postoperative adaptation. However, no tool currently exists for direct and easy patient evaluation. Purpose To evaluate lower urinary tract obstruction and postoperative adaptation using a four-dimensional (4D) virtual reality urination image (urodynamic 4D-CT image). Material and Methods We used a 320-row area detector CT scanner and PhyZiodynamics image analysis software to perform 197 urodynamic 4D-CT examinations on 175 first-time patients between January 2014 and March 2017. Results A comparison of the obtained images before and after holmium laser enucleation of the prostate revealed the morphological changes due to prostate enucleation and enabled visualization of the ideal urination conditions, showing that the anatomical structural changes during urination and the opening of the urethra play a major role in improving voiding function. Conclusion Using low-dosage radiation, the sharply defined moving image obtained via urodynamic 4D-CT examination can be utilized as a physiological diagnostic tool to evaluate a series of urinary movements from any angle between the prostate, urethra, and bladder in a unitary manner with the time axis added. There was negligible patient impact. This technique could provide new opportunities for the diagnosis of lower urinary tract symptoms and post-surgical adaptation assessment.

Traumatically Induced Brain Stem Hemorrhage and the Computerized Tomographic Scan

Neurosurgery ◽  
1979 ◽  
Vol 4 (2) ◽  
pp. 115-124 ◽  
Author(s):  
Paul R. Cooper ◽  
Kenneth Maravilla ◽  
Joel Kirkpatrick ◽  
Sarah F. Moody ◽  
Frederick H. Sklar ◽  
...  
Keyword(s):  
Ct Scan ◽  
Brain Stem ◽  
Thin Section ◽  
Ex Vivo ◽  
Ct Scanning ◽  
Volume Effect ◽  
Brain Parenchyma ◽  
Ct Scanner ◽  
Cross Sectional ◽  
The Brain

Abstract The computerized tomographic (CT) scan has revolutionized the management of cerebral trauma. Nevertheless, visualization of traumatically induced lesions of the brain stem by the CT scanner remains difficult. Seven patients with autopsy or CT evidence of brain stem hemorrhage were identified over a 1-year period. In six of these patients, brain stem hemorrhage could be defined by CT scan. As part of a prospective study of CT changes after head injury, we performed serial CT scans on six of the seven patients. Clinical experience shows that timing is important for identification of these lesions and that inability to visualize brain stem hematomas may occur because of the development of hematomas after CT scanning, evolution of hemorrhagic lesions that makes them isodense with the surrounding brain stem, patient movement, and technical factors such as the partial volume effect. Experimental injection of fresh blood into the pons and midbrain of cadavers shows that lesions as small as 0.1 ml in volume may be visualized by ex vivo thin section CT scanning techniques. However, the character and anatomical configuration of the hemorrhage may be as important in determining CT visualization as is the volume of the hemorrhage. For example, a hematoma displacing the brain parenchyma was visualized, but a similar-sized small hemorrhage that had diffused through the brain stem tissues was not. Although many of the experimentally placed lesions extended over a rostral-caudal length of 15 mm or more in the brain stem, no lesion was seen on more than three thin section scans. This is explained by the presence of lesions that, although extensive in a rostral-caudal direction, had relatively small cross sectional areas available for identification by the CT scanner. The small size of traumatic lesions of the brain stem and their proximity to bony structures at the base of the skull are not insurmountable obstacles to visualization of brain stem hemorrhages. Serial scanning and the application of thin section computed tomography will lead to identification of most of these lesions.

scholarly journals An Indirect Method to Measure Abutment Screw Preload: A Pilot Study Based on Micro-CT Scanning

2015 ◽  
Vol 26 (6) ◽  
pp. 596-601 ◽  
Author(s):  
Carlos Eduardo E. Rezende ◽  
Jason Alan Griggs ◽  
Yuanyuan Duan ◽  
Amanda M. Mushashe ◽  
Gisele Maria Correr Nolasco ◽  
...  
Keyword(s):  
Ct Scanning ◽  
Measuring Method ◽  
Micro Ct ◽  
Ct Scanner ◽  
Removal Torque ◽  
Ct Technique ◽  
Original Length ◽  
Implant Abutment ◽  
Torque Values ◽  
Abutment Screw

This study aimed to measure the preload in different implant platform geometries based on micro-CT images. External hexagon (EH) implants and Morse Tapered (MT) implants (n=5) were used for the preload measurement. The abutment screws were scanned in micro-CT to obtain their virtual models, which were used to record their initial length. The abutments were screwed on the implant with a 20 Ncm torque and the set composed by implant, abutment screw and abutment were taken to the micro-CT scanner to obtain virtual slices of the specimens. These slices allowed the measurement of screw lengths after torque application and based on the screw elongation. Preload values were calculated using the Hooke's Law. The preloads of both groups were compared by independent t-test. Removal torque of each specimen was recorded. To evaluate the accuracy of the micro-CT technique, three rods with known lengths were scanned and the length of their virtual model was measured and compared with the original length. One rod was scanned four times to evaluate the measuring method variation. There was no difference between groups for preload (EH = 461.6 N and MT = 477.4 N), but the EH group showed higher removal torque values (13.8±4.7 against 8.2±3.6 Ncm for MT group). The micro-CT technique showed a variability of 0.053% and repeatability showed an error of 0.23 to 0.28%. Within the limitations of this study, there was no difference between external hexagon and Morse taper for preload. The method using micro-CT may be considered for preload calculation.

scholarly journals A novel multiple-trauma CT-scanning protocol using patient repositioning

2006 ◽  
Vol 13 (3) ◽  
pp. 123-128 ◽  
Author(s):  
Hanno Hoppe ◽  
Peter Vock ◽  
Harald Marcel Bonel ◽  
Christoph Ozdoba ◽  
Jan Gralla
Keyword(s):  
Multiple Trauma ◽  
Ct Scanning ◽  
Scanning Protocol ◽  
Trauma Ct
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