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Journal articles on the topic '4D-CT'

Author: Grafiati

Published: 4 June 2021

Last updated: 20 February 2023

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1

Hoang, Jenny K., Katherine Williams, Frank Gaillard, Andrew Dixon, and Julie A. Sosa. "Parathyroid 4D-CT." Otolaryngology–Head and Neck Surgery 155, no. 6 (July 22, 2016): 956–60. http://dx.doi.org/10.1177/0194599816655311.

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2

Pretet, Valentin, Marianela Rotania, Mehdi Helali, Mihaela Ignat, Michel Vix, and Alessio Imperiale. "18F-Fluorocholine PET and Multiphase CT Integrated in Dual Modality PET/4D-CT for Preoperative Evaluation of Primary Hyperparathyroidism." Journal of Clinical Medicine 9, no. 6 (June 26, 2020): 2005. http://dx.doi.org/10.3390/jcm9062005.

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The present retrospective study evaluates the diagnostic value of integrated 18F-Fluorocholine positron emission tomography/four-dimensional contrast-enhanced computed tomography (18F-FCH PET/4D-CT) as second-line imaging in preoperative work-up of primary hyperparathyroidism (pHPT), and compares 18F-FCH PET with 4D-CT. Patients with pHPT and negative/discordant first-line imaging addressed for integrated 18F-FCH PET/4D-CT were retrospectively selected. Sensitivity and detection rate (DR%) of 18F-FCH PET/CT, 4D-CT, and PET/4D-CT were calculated according to the per patient and per lesion analyses, and afterwards compared. Histology associated with a decrease more than 50% of perioperative parathyroid hormone (PTH) blood level was used as a gold standard. Persistent high serum PTH and calcium levels during a 6-month follow-up was considered as presence of pHPT in both operated and non-operated patients. 50 patients (55 glands) were included. 44/50 patients (88%) were surgically treated. On a per patient analysis, sensitivity was 93%, 80%, and 95%, and DR% was 82%, 68%, and 84%, respectively for PET/CT, 4D-CT, and PET/4D-CT. PET/CT was more sensitive than 4D-CT (p = 0.046). PET/4D-CT performed better than 4D-CT (p = 0.013) but was equivalent to PET/CT alone. On a per gland analysis, sensitivity PET/CT, 4D-CT, and PET/4D-CT was 88%, 66%, and 92%, and DR% was 79%, 57%, and 83%, respectively. PET/CT and PET/4D-CT were more sensitive than 4D-CT alone (p = 0.01, p < 0.001, respectively). However, PET/CT and PET/4D-CT performed similarly. In conclusion, 18F-FCH PET provides better identification of hyperfunctioning parathyroids than 4D-CT and the combination of both did not significantly improve diagnostic sensitivity. Further investigations involving larger populations are necessary to define the role of 18F-FCH PET/4D-CT as a “one-stop shop” second-line imaging in preoperative work-up of pHPT, especially considering the additional patient radiation exposure due to multi-phase CT.

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3

Latge, Adrien, Sophie Riehm, Michel Vix, Jacob Bani, Mihaela Ignat, Valentin Pretet, Mehdi Helali, Giorgio Treglia, and Alessio Imperiale. "18F-Fluorocholine PET and 4D-CT in Patients with Persistent and Recurrent Primary Hyperparathyroidism." Diagnostics 11, no. 12 (December 17, 2021): 2384. http://dx.doi.org/10.3390/diagnostics11122384.

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Patients with primary hyperparathyroidism (pHPT) can develop persistent (P-pHPT) or recurrent (R-pHPT) disease after parathyroidectomy. Before recommending reoperation, recurrence must be accurately identified because of the high risk of complications. Our study evaluates 18F-fluorocholine (18F-FCH) PET/CT and 4D-CT integrated in PET/4D-CT in patients with P-pHPT/R-pHPT. Patients with P-pHPT/R-pHPT investigated by 18F-FCH PET/4D-CT between May 2018 and March 2021 were retrospectively included. Forty-two patients were included, 37 of whom underwent 4D-CT. The sensitivity and detection rate (DR%) were 95% and 88% for 18F-FCH PET/CT and 70% and 63% for 4D-CT, respectively. PET/CT and 4D-CT were concordant in 18/24 glands and concordant and positive in 15/24 (63%) glands. Discordant results were obtained for 6/24 glands. The surgical success rate was 65%. PET/CT showed significantly higher sensitivity than 4D-CT. Dynamic CT allowed the identification of no additional glands missed by PET/CT, and the combination of the 2 techniques did not improve the sensitivity or DR%. 18F-FCH PET/CT appears to be a valuable technique to accurately detect hyperfunctioning parathyroid tissue in patients with P-pHPT/R-pHPT and is better than 4D-CT. Except for cases with doubtful locations of PET targets that may require 4D-CT for surgical guidance, standard nonenhanced 18F-FCH PET/CT can be effectively recommended in patients with P-pHPT/R-pHPT before reoperation.

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Yamamoto, Tokihiro, Sven Kabus, Cristian Lorenz, Eric Johnston, Peter G. Maxim, Maximilian Diehn, Neville Eclov, Cristian Barquero, Billy W. Loo, and Paul J. Keall. "4D CT lung ventilation images are affected by the 4D CT sorting method." Medical Physics 40, no. 10 (September 11, 2013): 101907. http://dx.doi.org/10.1118/1.4820538.

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5

Maric, Slavica, Petar Janjic, Borut Bosancic, Milan Mijailovic, and Snezana Lukic. "Importance of four-dimensional computed tomography simulation in locally advanced lung cancer radiotherapy: Impact on reducing planning target volume." Vojnosanitetski pregled, no. 00 (2021): 96. http://dx.doi.org/10.2298/vsp210520096m.

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Background/Aim. Four dimensional (4DCT) simulation is a useful tool for motion assessment in lung cancer radiotherapy. Conventional Three dimensional (3D) - Free Breathing simulation is static, with limited motion information. The aim of this study was to compare clinically significant differences between the target volumes defined on 3D CT vs. 4D CT simulation and potential impact on the planning target volume (PTV). In addition, to quantify movements of primary tumour (GTV) during 4D CT simulation on three axis -Z-supero inferior (SI), X-mediolateral (ML), and Y-anteroposterior (AP). Methods. This retrospective study evaluated 20 lung cancer patients who underwent CT simulation for radical radiotherapy treatment. Free Breathing 3D CT and 4D CT simulation were acquired for each patient in accordance with our institutional protocol. Volumetric comparison radiation volumes defined on 3D CT vs. 4D CT simulation was done-Gross tumour volume GTV 3D vs. internal GTV- (iGTV 4D) and PTV 3D vs. iPTV 4D. Volumetric values expressed in cm3 and equivalent spherical diameter (ESD) expressed in cm were assessed. Comparison of GTV movement in the phase FB-GTV FB, phase 0-GTV0, phase 50-GTV 50, and phase Maximum intensity projection (MIP) -GTV MIP was made with GTV FB as the basic value. The evaluation was made in three axis. Results. Comparison volumetric values between GTV 3D vs. iGTV 4D was 63.15 vs.85.51 (p<0.001) respectively. iGTV 4D was significantly larger than GTV 3D (p<0.001). The mean value (ESD) PTV 3D vs.iPTV 4D was 8.44 vs. 7.82 (p<0.001) respectively, and mean value volume PTV 3D vs. iPTV 4D was 352.70 vs. 272.78 (p<0.001) respectively. PTV 3D was significantly larger than iPTV 4D (p<0.001). Statistically significant difference (p<0.05) was identified in the deviation related to Z axis between the upper and lower lobe. Conclusion. 4D CT simulation based delineation can reduce planning target volume compared to 3D simulation based radiation therapy and therefore, it is a prerequisite for high-quality and precise radiation therapy treatment.

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6

Galvin, Leo, Jorge D. Oldan, Manisha Bahl, James D. Eastwood, Julie A. Sosa, and Jenny K. Hoang. "Parathyroid 4D CT and Scintigraphy." Otolaryngology–Head and Neck Surgery 154, no. 5 (March 2016): 847–53. http://dx.doi.org/10.1177/0194599816630711.

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7

Reinartz, Gabriele, Uwe Haverkamp, Ramona Wullenkord, Philipp Lehrich, Jan Kriz, Florian Büther, Klaus Schäfers, Michael Schäfers, and Hans Theodor Eich. "4D-Listmode-PET-CT and 4D-CT for optimizing PTV margins in gastric lymphoma." Strahlentherapie und Onkologie 192, no. 5 (February 22, 2016): 322–32. http://dx.doi.org/10.1007/s00066-016-0949-0.

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8

Gill, Gurman, and Reinhard R. Beichel. "Lung Segmentation in 4D CT Volumes Based on Robust Active Shape Model Matching." International Journal of Biomedical Imaging 2015 (2015): 1–9. http://dx.doi.org/10.1155/2015/125648.

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Dynamic and longitudinal lung CT imaging produce 4D lung image data sets, enabling applications like radiation treatment planning or assessment of response to treatment of lung diseases. In this paper, we present a 4D lung segmentation method that mutually utilizes all individual CT volumes to derive segmentations for each CT data set. Our approach is based on a 3D robust active shape model and extends it to fully utilize 4D lung image data sets. This yields an initial segmentation for the 4D volume, which is then refined by using a 4D optimal surface finding algorithm. The approach was evaluated on a diverse set of 152 CT scans of normal and diseased lungs, consisting of total lung capacity and functional residual capacity scan pairs. In addition, a comparison to a 3D segmentation method and a registration based 4D lung segmentation approach was performed. The proposed 4D method obtained an average Dice coefficient of0.9773±0.0254, which was statistically significantly better (pvalue≪0.001) than the 3D method (0.9659±0.0517). Compared to the registration based 4D method, our method obtained better or similar performance, but was 58.6% faster. Also, the method can be easily expanded to process 4D CT data sets consisting of several volumes.

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Ehrhardt, J., T. Frenzel, D. Säring, W. Lu, D. Low, H. Handels, and R. Werner. "Motion Artifact Reducing Reconstruction of 4D CT Image Data for the Analysis of Respiratory Dynamics." Methods of Information in Medicine 46, no. 03 (2007): 254–60. http://dx.doi.org/10.1160/me9040.

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Summary Objectives: Respiratory motion represents a major problem in radiotherapy of thoracic and abdominal tumors. Methods for compensation require comprehensive knowledge of underlying dynamics. Therefore, 4D (= 3D + t) CT data can be helpful. But modern CT scanners cannot scan a large region of interest simultaneously. So patients have to be scanned in segments. Commonly used approaches for reconstructing the data segments into 4D CT images cause motion artifacts. In orderto reduce the artifacts, a new method for 4D CT reconstruction is presented. The resulting data sets are used to analyze respiratory motion. Methods: Spatiotemporal CT image sequences of lung cancer patients were acquired using a multi-slice CT in cine mode during free breathing. 4D CT reconstruction was done by optical flow based temporal interpolation. The resulting 4D image data were compared with data generated bythe commonly used nearest neighbor reconstruction. Subsequent motion analysis is mainly concerned with tumor mobility. Results: The presented optical flow-based method enables the reconstruction of 3D CT images at arbitrarily chosen points of the patient’s breathing cycle. A considerable reduction of motion artifacts has been proven in eight patient data sets. Motion analysis showed that tumor mobility differs strongly between the patients. Conclusions: Due to the proved reduction of motion artifacts, the optical flow-based 4D CT reconstruction offers the possibility of high-quality motion analysis. Because the method is based on an interpolation scheme, it additionally has the potential to enable the reconstruction of 4D CT data from a lesser number of scans.

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10

Lantz, Jonas, Vikas Gupta, Lilian Henriksson, Matts Karlsson, Anders Persson, Carl-Johan Carlhäll, and Tino Ebbers. "Intracardiac Flow at 4D CT: Comparison with 4D Flow MRI." Radiology 289, no. 1 (October 2018): 51–58. http://dx.doi.org/10.1148/radiol.2018173017.

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11

Yamamoto, T., S. Kabus, C. Lorenz, E. Johnston, P. Maxim, B. Loo, and P. Keall. "SU-D-BRB-01: 4D-CT Lung Ventilation Images Vary with 4D-CT Sorting Techniques." Medical Physics 39, no. 6Part3 (June 2012): 3614. http://dx.doi.org/10.1118/1.4734673.

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12

Zhang, Zeyu, Mi Huang, Zhuoran Jiang, Yushi Chang, Ke Lu, Fang-Fang Yin, Phuoc Tran, Dapeng Wu, Chris Beltran, and Lei Ren. "Patient-specific deep learning model to enhance 4D-CBCT image for radiomics analysis." Physics in Medicine & Biology 67, no. 8 (April 1, 2022): 085003. http://dx.doi.org/10.1088/1361-6560/ac5f6e.

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Abstract Objective. 4D-CBCT provides phase-resolved images valuable for radiomics analysis for outcome prediction throughout treatment courses. However, 4D-CBCT suffers from streak artifacts caused by under-sampling, which severely degrades the accuracy of radiomic features. Previously we developed group-patient-trained deep learning methods to enhance the 4D-CBCT quality for radiomics analysis, which was not optimized for individual patients. In this study, a patient-specific model was developed to further improve the accuracy of 4D-CBCT based radiomics analysis for individual patients. Approach. This patient-specific model was trained with intra-patient data. Specifically, patient planning 4D-CT was augmented through image translation, rotation, and deformation to generate 305 CT volumes from 10 volumes to simulate possible patient positions during the onboard image acquisition. 72 projections were simulated from 4D-CT for each phase and were used to reconstruct 4D-CBCT using FDK back-projection algorithm. The patient-specific model was trained using these 305 paired sets of patient-specific 4D-CT and 4D-CBCT data to enhance the 4D-CBCT image to match with 4D-CT images as ground truth. For model testing, 4D-CBCT were simulated from a separate set of 4D-CT scan images acquired from the same patient and were then enhanced by this patient-specific model. Radiomics features were then extracted from the testing 4D-CT, 4D-CBCT, and enhanced 4D-CBCT image sets for comparison. The patient-specific model was tested using 4 lung-SBRT patients’ data and compared with the performance of the group-based model. The impact of model dimensionality, region of interest (ROI) selection, and loss function on the model accuracy was also investigated. Main results. Compared with a group-based model, the patient-specific training model further improved the accuracy of radiomic features, especially for features with large errors in the group-based model. For example, the 3D whole-body and ROI loss-based patient-specific model reduces the errors of the first-order median feature by 83.67%, the wavelet LLL feature maximum by 91.98%, and the wavelet HLL skewness feature by 15.0% on average for the four patients tested. In addition, the patient-specific models with different dimensionality (2D versus 3D) or loss functions (L1 versus L1 + VGG + GAN) achieved comparable results for improving the radiomics accuracy. Using whole-body or whole-body+ROI L1 loss for the model achieved better results than using the ROI L1 loss alone as the loss function. Significance. This study demonstrated that the patient-specific model is more effective than the group-based model on improving the accuracy of the 4D-CBCT radiomic features analysis, which could potentially improve the precision for outcome prediction in radiotherapy.

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13

Zhang, Shu-xu, Ling-hong Zhou, Sheng-qu Lin, Hui Yu, Guo-quan Zhang, Rui-hao Wang, and Bing Qi. "4D-CT reconstruction based on pulmonary average CT values." Bio-Medical Materials and Engineering 24, no. 1 (2014): 85–94. http://dx.doi.org/10.3233/bme-130787.

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14

Pan, Tinsu, Xiaojun Sun, and Dershan Luo. "Improvement of the cine-CT based 4D-CT imaging." Medical Physics 34, no. 11 (October 29, 2007): 4499–503. http://dx.doi.org/10.1118/1.2794225.

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15

Buzzatti, Luca, Benyameen Keelson, Johan Vanlauwe, Nico Buls, Johan De Mey, Jef Vandemeulebroucke, Erik Cattrysse, and Thierry Scheerlinck. "Evaluating lower limb kinematics and pathology with dynamic CT." Bone & Joint Journal 103-B, no. 5 (May 1, 2021): 822–27. http://dx.doi.org/10.1302/0301-620x.103b5.bjj-2020-1064.r2.

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Evaluating musculoskeletal conditions of the lower limb and understanding the pathophysiology of complex bone kinematics is challenging. Static images do not take into account the dynamic component of relative bone motion and muscle activation. Fluoroscopy and dynamic MRI have important limitations. Dynamic CT (4D-CT) is an emerging alternative that combines high spatial and temporal resolution, with an increased availability in clinical practice. 4D-CT allows simultaneous visualization of bone morphology and joint kinematics. This unique combination makes it an ideal tool to evaluate functional disorders of the musculoskeletal system. In the lower limb, 4D-CT has been used to diagnose femoroacetabular impingement, patellofemoral, ankle and subtalar joint instability, or reduced range of motion. 4D-CT has also been used to demonstrate the effect of surgery, mainly on patellar instability. 4D-CT will need further research and validation before it can be widely used in clinical practice. We believe, however, it is here to stay, and will become a reference in the diagnosis of lower limb conditions and the evaluation of treatment options. Cite this article: Bone Joint J 2021;103-B(5):822–827.

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Smaxwil, Constantin, Philip Aschoff, Gerald Reischl, Mirjam Busch, Joachim Wagner, Julia Altmeier, Oswald Ploner, and Andreas Zielke. "[18F]fluoro-ethylcholine-PET Plus 4D-CT (FEC-PET-CT): A Break-Through Tool to Localize the “Negative” Parathyroid Adenoma. One Year Follow Up Results Involving 170 Patients." Journal of Clinical Medicine 10, no. 8 (April 13, 2021): 1648. http://dx.doi.org/10.3390/jcm10081648.

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Background: The diagnostic performance of [18F]fluoro-ethylcholine-PET-CT&4D-CT (FEC-PET&4D-CT) to identify parathyroid adenomas (PA) was analyzed when ultrasound (US) or MIBI-Scan (MS) failed to localize. Postsurgical one year follow-up data are presented. Methods: Patients in whom US and MS delivered either incongruent or entirely negative findings were subjected to FEC-PET&4D-CT and cases from July 2017 to June 2020 were analyzed, retrospectively. Cervical exploration with intraoperative PTH-monitoring (IO-PTH) was performed. Imaging results were correlated to intraoperative findings, and short term and one year postoperative follow-up data. Results: From July 2017 to June 2020 in 171 FEC-PET&4D-CTs 159 (92.9%) PAs were suggested. 147 patients already had surgery, FEC-PET&4D-CT accurately localized in 141; false neg. 4, false pos. 2, global sensitivity 0.97; accuracy 0.96, PPV 0.99. All of the 117 patients that already have completed their 12-month postoperative follow up had normal biochemical parameter, i.e., no signs of persisting disease. However, two cases may have a potential for recurrent disease, for a cure rate of at least 98.3%. Conclusion: FEC-PET&4D-CT shows unprecedented results regarding the accuracy localizing PAs. The one-year-follow-up data demonstrate a high cure rate. We, therefore, suggest FEC-PET-CT as the relevant diagnostic tool for the localization of PAs when US fails to localize PA, especially after previous surgery to the neck.

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Geets, X. "4D PET-CT guided radiation therapy." Journal of the Belgian Society of Radiology 96, no. 3 (May 1, 2013): 155. http://dx.doi.org/10.5334/jbr-btr.236.

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18

Werner, R., T. Sentker, F. Madesta, T. Gauer, and C. Hofmann. "Intelligent 4D CT Sequence Scanning (i4DCT)." International Journal of Radiation Oncology*Biology*Physics 102, no. 3 (November 2018): S5. http://dx.doi.org/10.1016/j.ijrobp.2018.06.108.

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19

Schoepf, U. Joseph, and Akos Varga-Szemes. "4D Flow Meets CT: Can It Compete with 4D Flow MRI?" Radiology 289, no. 1 (October 2018): 59–60. http://dx.doi.org/10.1148/radiol.2018181210.

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20

Kartika Sari, Ni Larasati, Merry Suzana, Muzilman Muslim, and Dewi Muliyati. "ANALYSIS OF THE EFFECT OF CARE DOSE 4D SOFTWARE USE ON IMAGE QUALITY AND RADIATION DOSE ON THE CT SCAN ABDOMEN." Spektra: Jurnal Fisika dan Aplikasinya 5, no. 1 (April 30, 2020): 31–40. http://dx.doi.org/10.21009/spektra.051.04.

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The CT Scan is the most significant contributor to radiation dose on radiological examination, although the frequency of the examination is far below other modalities. In order to control this radiation dose, manufactures of CT Scan have equipped their units with built-in software called Automatic Exposure Control (AEC). This study aims to analyze the effect of AEC software, CARE Dose 4D, on image quality, and CTDIvol. Objects used in this study were three water phantoms, each with a diameter of 165 mm, 230 mm, and 305 mm. The image quality-analyzed was CT Number and noise. Measurement of image quality was carried out following Bapeten's provisions. Noise Power Spectrum (NPS) graphics were also used to further observes noise texture. The CT Number accuracy, CT Number, and noise uniformity obtained with and without CARE Dose 4D, on the three phantoms were still within Bapeten's threshold. This indicates that the use of CARE Dose 4D can still image a homogeneous object accurately. The results of the NPS curve showed that the two modes, in three phantoms, were having the same noise texture. The NPS curves also showed that the use of CARE Dose 4D produces higher noise than the non-CARE Dose 4D mode. Meanwhile, there were significant differences from the CTDIvol obtained from the two modes. The use of CARE Dose 4D software reduced dose of up to 54.34%. From this, the use of CARE Dose 4D software can reduce the radiation dose while maintaining image quality.

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21

Kedarisetty, Suraj, Christopher Fundakowski, Karthika Ramakrishnan, and Simin Dadparvar. "Clinical Value of Tc99m-MIBI SPECT/CT Versus 4D-CT or US in Management of Patients With Hyperparathyroidism." Ear, Nose & Throat Journal 98, no. 3 (February 19, 2019): 149–57. http://dx.doi.org/10.1177/0145561319828668.

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Localization of parathyroid adenomas for treatment of primary hyperparathyroidism can be challenging. This retrospective study compared single-photon emission computed tomography/computed tomography (SPECT/CT), 4D-CT, and US studies in detection of adenomas prior to surgery. A retrospective chart review was performed on all consecutive patients with parathyroid adenoma presenting to an urban tertiary care medical center. A total of 58 patients (45 female, 13 male) underwent surgery for parathyroid adenoma. Patients aged 28 to 80 years (mean: 58.8) with parathyroid hormone levels ranging from 42 to 424 pg/mL (mean: 168). All patients underwent preoperative SPECT/CT with 20 mCi technetium-99m MIBI (99mTc-MIBI). Fifty-three patients had additional US imaging and 14 patients had 4D-CT scans. Additionally, 34 patients had injection of 20 mCi 99mTc-MIBI on the day of surgery. Pathological correlation was performed. Comparing SPECT/CT versus 4D-CT resulted in sensitivity (77% vs 80%), specificity (71% vs 75%), and accuracy (77% vs 79%). Ultrasound was less sensitive with similar specificity (44%, 86%, respectively). Combination of SPECT/CT and 4D-CT increased sensitivity to 88%, specificity to 100%, and accuracy to 89%. Combining SPECT/CT with US resulted in sensitivity of 85%, specificity of 83%, and accuracy of 85%. Intraoperative localization substantially improved in patients who received preoperative injections. The SPECT/CT remains the best imaging modality for preoperative localization of parathyroid adenomas with high sensitivity. Combining SPECT/CT with US resulted in increased sensitivity and accuracy. For suspicion of ectopic cases or suspicion of unidentifiable adenoma with negative scintigraphy, addition of 4D-CT is recommended. Intraoperative localization and adjunctive imaging may improve surgical management of patients with hyperparathyroidism.

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22

Ahmed, Naseer, Sankar Venkataraman, Kate Johnson, Keith Sutherland, and Shaun K. Loewen. "Does Motion Assessment With 4-Dimensional Computed Tomographic Imaging for Non–Small Cell Lung Cancer Radiotherapy Improve Target Volume Coverage?" Clinical Medicine Insights: Oncology 11 (January 1, 2017): 117955491769846. http://dx.doi.org/10.1177/1179554917698461.

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Introduction: Modern radiotherapy with 4-dimensional computed tomographic (4D-CT) image acquisition for non–small cell lung cancer (NSCLC) captures respiratory-mediated tumor motion to provide more accurate target delineation. This study compares conventional 3-dimensional (3D) conformal radiotherapy (3DCRT) plans generated with standard helical free-breathing CT (FBCT) with plans generated on 4D-CT contoured volumes to determine whether target volume coverage is affected. Materials and methods: Fifteen patients with stage I to IV NSCLC were enrolled in the study. Free-breathing CT and 4D-CT data sets were acquired at the same simulation session and with the same immobilization. Gross tumor volume (GTV) for primary and/or nodal disease was contoured on FBCT (GTV_3D). The 3DCRT plans were obtained, and the patients were treated according to our institution’s standard protocol using FBCT imaging. Gross tumor volume was contoured on 4D-CT for primary and/or nodal disease on all 10 respiratory phases and merged to create internal gross tumor volume (IGTV)_4D. Clinical target volume margin was 5 mm in both plans, whereas planning tumor volume (PTV) expansion was 1 cm axially and 1.5 cm superior/inferior for FBCT-based plans to incorporate setup errors and an estimate of respiratory-mediated tumor motion vs 8 mm isotropic margin for setup error only in all 4D-CT plans. The 3DCRT plans generated from the FBCT scan were copied on the 4D-CT data set with the same beam parameters. GTV_3D, IGTV_4D, PTV, and dose volume histogram from both data sets were analyzed and compared. Dice coefficient evaluated PTV similarity between FBCT and 4D-CT data sets. Results: In total, 14 of the 15 patients were analyzed. One patient was excluded as there was no measurable GTV. Mean GTV_3D was 115.3 cm3 and mean IGTV_4D was 152.5 cm3 ( P = .001). Mean PTV_3D was 530.0 cm3 and PTV_4D was 499.8 cm3 ( P = .40). Both gross primary and nodal disease analyzed separately were larger on 4D compared with FBCT. D95 (95% isodose line) covered 98% of PTV_3D and 88% of PTV_4D ( P = .003). Mean dice coefficient of PTV_3D and PTV_4D was 84%. Mean lung V20 was 24.0% for the 3D-based plans and 22.7% for the 4D-based plans ( P = .057). Mean heart V40 was 12.1% for the 3D-based plans and 12.7% for the 4D-based plans ( P = .53). Mean spinal cord Dmax was 2517 and 2435 cGy for 3D-based and 4D-based plans, respectively ( P = .019). Mean esophageal dose was 1580 and 1435 cGy for 3D and 4D plans, respectively ( P = .13). Conclusions: IGTV_4D was significantly larger than GTV_3D for both primary and nodal disease combined or separately. Mean PTV_3D was larger than PTV_4D, but the difference was not statistically significant. The PTV_4D coverage with 95% isodose line was inferior, indicating the importance of incorporating the true size and shape of the target volume. Relatively less dose was delivered to spinal cord and esophagus with plans based on 4D data set. Dice coefficient analysis for degree of similarity revealed that 16% of PTVs from both data sets did not overlap, indicating different anatomical positions of the PTV due to tumor/nodal motion during a respiratory cycle. All patients with lung cancer planned for radical radiotherapy should have 4D-CT simulation to ensure accurate coverage of the target volumes.

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Hoinkis, C., S. Appold, W. Enghardt, N. Abolmaali, C. Reiffenstuhl, C. Richter, D. Zips, K. Zoephel, J. Kotzerke, and M. Baumann. "COMPARISON OF 4D-PET/4D-CT/4D-MRI TREATMENT PLANNING FOR RADIOTHERAPY OF LUNG CANCER." Radiotherapy and Oncology 92 (August 2009): S163. http://dx.doi.org/10.1016/s0167-8140(12)73015-3.

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24

Kumar, S. S., K. Mathew, M. S. Czaplicki, P. V. Manickam, W. Quinones, N. C. Purdy, T. T. Ly, A. Moreno De Luca, K. M. Sargar, and G. J. Mongelluzzo. "Breaking the Rules: Nonclassic Appearances of Parathyroid Adenomas." Neurographics 12, no. 3 (July 1, 2022): 162–68. http://dx.doi.org/10.3174/ng.2100052.

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At many institutions, 4D-CT has become the first-line technique for localizing candidate parathyroid adenomas before surgical resection. The appearance of the classic parathyroid adenoma on 4D-CT is well described in the literature, including enhancement pattern, morphology, and typical locations. However, readers of 4D-CT are quick to learn that many parathyroid adenomas do not conform to this conventional appearance. We will review both the classic appearance of parathyroid adenoma on 4D-CT as well as variations in appearance and location that are important to know for successful lesion localization. Familiarity with histologically proved adenomas that deviate from the classic appearance enables practicing neuroradiologists to more effectively identify potential candidate lesions, aiding the surgeon in rendering a cure.Learning Objective: To describe the nonclassic appearance of parathyroid adenomas to improve preoperative identification of candidate lesions

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Nishimura, Takamasa, Eijun Sueyoshi, Yuichi Tasaki, and Masataka Uetani. "Asymptomatic floating thrombus in the ascending aorta depicted on four-dimensional computed tomography." SAGE Open Medical Case Reports 8 (January 2020): 2050313X2097189. http://dx.doi.org/10.1177/2050313x20971894.

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Aortic mural thrombi of the ascending aorta are rare. If an aortic mural thrombus is dislodged, it can cause various embolic complications, which can sometimes be fatal. Although contrast-enhanced computed tomography (CT) and transesophageal echography are useful for diagnosing aortic mural thrombi, four-dimensional CT (4D-CT) is one of the most useful modalities for both diagnosis and treatment selection in such cases. 4D-CT can be used to evaluate the morphology and mobility of thrombi. Furthermore, it is minimally invasive. To the best of our knowledge, there have not been any reports about 4D-CT being used to depict an asymptomatic ascending aortic thrombus. We report a very unusual case, involving an aortic mural thrombus of the ascending aorta.

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Nagano, Stephanie Yuka Matwijszyn, Almir Galvão Vieira Bitencourt, Ivone do Carmo Gonçalves Torres, and Gislaine Cristina Lopes Machado Porto. "Four-dimensional computed tomography protocol for preoperative evaluation of the parathyroid glands and its correlations with other imaging methods: a pictorial essay." Radiologia Brasileira 54, no. 3 (June 2021): 193–97. http://dx.doi.org/10.1590/0100-3984.2020.0056.

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Abstract Parathyroid adenoma is the most common cause of primary hyperparathyroidism. Advances in surgical techniques have made it possible to excise only the affected parathyroid gland in most cases. Imaging examinations play a fundamental role in the preoperative planning of parathyroidectomy. To localize the parathyroid glands, imaging tests such as scintigraphy, ultrasound, and, more recently, four-dimensional computed tomography (4D CT). The aim of this pictorial review was to illustrate the use of the 4D CT protocol in cases of parathyroid adenoma and to determine how well it correlates with other imaging methods, in order to improve understanding of the 4D CT method.

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Park, S., J. Jung, J. Kim, I. Yeo, and B. Yi. "SU-F-J-118: On-Treatment 4D CT Reconstruction From Planning 4D CT Using Linear Amplitude Scaling." Medical Physics 43, no. 6Part10 (June 2016): 3434. http://dx.doi.org/10.1118/1.4956026.

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Trần, Đức Linh, Quang Huy Đặng, and Đức Công Nguyễn. "GIÁ TRỊ CỦA MÔ PHỎNG BẰNG CT 4D TRONG LẬP KẾ HOẠCH XẠ TRỊ UNG THƯ PHỔI KHÔNG TẾ BÀO NHỎ GIAI ĐOẠN III." VietNam Military Medical Unisversity 47, no. 9 (December 1, 2022): 26–35. http://dx.doi.org/10.56535/jmpm.v47i9.208.

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Mục tiêu: Đánh giá sự thay đổi của các thể tích xạ trị và liều trên các cơ quan nguy cấp giữa kế hoạch dựa trên mô phỏng CT 3D và 4D. Đối tượng và phương pháp: Nghiên cứu mô tả cắt ngang hồi cứu kết hợp tiến cứu trên 31 bệnh nhân (BN) ung thư phổi không tế bào nhỏ (UTPKTBN) được xạ trị tại Bệnh viện Quân y 175 từ tháng 7/2020 - 7/2022. Thể tích khối u thô được xác định trên hình ảnh CT thể tích khối u thô 3D (Gross target volume - GTV 3D) và trên 10 pha của hình ảnh CT 4D (Internal target volume - ITV hay GTV 4D) ở 31 BN UTP KTBN giai đoạn III. Kế hoạch xạ trị 3D được lập dựa trên thể tích lập kế hoạch 3D (Planning target volume - PTV), thể tích bia lâm sàng (Clinical target volume - CTV cộng biên theo hướng dẫn thường quy), kế hoạch 4D được lập dựa trên PTV 4D (CTV trên 10 pha cộng thêm sai số đặt bệnh). Các thể tích xạ trị và liều trên phổi, tim, thực quản, tủy sống được so sánh giữa kế hoạch 3D và 4D. Kết quả: Trung bình GTV 4D (111,4 ± 69,4 cm³) lớn hơn trung bình GTV 3D (77,7 ± 54,2 cm³) (p = 0,001), tuy vậy trung bình của PTV trên kế hoạch 4D (401,8 ± 167,3 cm³) lại nhỏ hơn trên kế hoạch 3D (460,2 ± 179,1 cm³) (p = 0,002). Kế hoạch 4D bảo vệ các cơ quan lành xung quanh tốt hơn 3D, đặc biệt là trên phổi. So với kế hoạch 3D, liều trung bình phổi, V5, V10, V20 của phổi giảm lần lượt từ 18,3Gy, 59,9%, 55,8%, 40,5% xuống 16,9Gy, 44,6%, 31,2%, 28,9%. Liều trung bình tim, thực quản và liều tối đa tủy sống trên kế hoạch 4D giảm so với 3D (13,1 Gy, 18,7 Gy và 37,9 Gy so với 15,8 Gy, 19,1 Gy và 40 Gy), tuy nhiên khác biệt không có ý nghĩa thống kê (p > 0,05). Kết luận: Lập kế hoạch cho BN UTPKTBN dựa trên mô phỏng bằng CT 4D giúp giảm thể tích xạ trị, bảo vệ các cơ quan lành tốt hơn mô phỏng bằng CT 3D.

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Gianoli, C., G. Fontana, M. Riboldi, C. Cavedon, and G. Baroni. "174 oral ENHANCED 4D PET OPTIMIZATION BASED ON 4D CT MOTION MODELING." Radiotherapy and Oncology 99 (May 2011): S67—S68. http://dx.doi.org/10.1016/s0167-8140(11)70296-1.

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Han, Min Cheol, Jihun Kim, Chae-Seon Hong, Kyung Hwan Chang, Su Chul Han, Kwangwoo Park, Dong Wook Kim, et al. "Performance Evaluation of Deformable Image Registration Algorithms Using Computed Tomography of Multiple Lung Metastases." Technology in Cancer Research & Treatment 21 (January 2022): 153303382210784. http://dx.doi.org/10.1177/15330338221078464.

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Purpose: Various deformable image registration (DIR) methods have been used to evaluate organ deformations in 4-dimensional computed tomography (4D CT) images scanned during the respiratory motions of a patient. This study assesses the performance of 10 DIR algorithms using 4D CT images of 5 patients with fiducial markers (FMs) implanted during the postoperative radiosurgery of multiple lung metastases. Methods: To evaluate DIR algorithms, 4D CT images of 5 patients were used, and ground-truths of FMs and tumors were generated by physicians based on their medical expertise. The positions of FMs and tumors in each 4D CT phase image were determined using 10 DIR algorithms, and the deformed results were compared with ground-truth data. Results: The target registration errors (TREs) between the FM positions estimated by optical flow algorithms and the ground-truth ranged from 1.82 ± 1.05 to 1.98 ± 1.17 mm, which is within the uncertainty of the ground-truth position. Two algorithm groups, namely, optical flow and demons, were used to estimate tumor positions with TREs ranging from 1.29 ± 1.21 to 1.78 ± 1.75 mm. With respect to the deformed position for tumors, for the 2 DIR algorithm groups, the maximum differences of the deformed positions for gross tumor volume tracking were approximately 4.55 to 7.55 times higher than the mean differences. Errors caused by the aforementioned difference in the Hounsfield unit values were also observed. Conclusions: We quantitatively evaluated 10 DIR algorithms using 4D CT images of 5 patients and compared the results with ground-truth data. The optical flow algorithms showed reasonable FM-tracking results in patient 4D CT images. The iterative optical flow method delivered the best performance in this study. With respect to the tumor volume, the optical flow and demons algorithms delivered the best performance.

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Fast, Martin F., Eric Wisotzky, Uwe Oelfke, and Simeon Nill. "Actively triggered 4d cone-beam CT acquisition." Medical Physics 40, no. 9 (August 12, 2013): 091909. http://dx.doi.org/10.1118/1.4817479.

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Brandner, Edward D., Andrew Wu, Hungcheng Chen, Dwight Heron, Shalom Kalnicki, Krishna Komanduri, Kristina Gerszten, Steve Burton, Irfan Ahmed, and Zhenyu Shou. "Abdominal organ motion measured using 4D CT." International Journal of Radiation Oncology*Biology*Physics 65, no. 2 (June 2006): 554–60. http://dx.doi.org/10.1016/j.ijrobp.2005.12.042.

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Guo, Xiaolian, Samuel M. Johnston, Yi Qi, G. Allan Johnson, and Cristian T. Badea. "4D micro-CT using fast prospective gating." Physics in Medicine and Biology 57, no. 1 (December 9, 2011): 257–71. http://dx.doi.org/10.1088/0031-9155/57/1/257.

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Beijer, Tim R., Ewoud J. van Dijk, Joost de Vries, Sarah E. Vermeer, Mathias Prokop, and Frederick J. A. Meijer. "4D-CT angiography differentiating arteriovenous fistula subtypes." Clinical Neurology and Neurosurgery 115, no. 8 (August 2013): 1313–16. http://dx.doi.org/10.1016/j.clineuro.2012.12.015.

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Chandran, Arun, Mark Radon, Shubhabrata Biswas, Kumar Das, Mani Puthuran, and Hans Nahser. "Republished: Novel use of 4D-CTA in imaging of intranidal aneurysms in an acutely ruptured arteriovenous malformation: is this the way forward?" Journal of NeuroInterventional Surgery 8, no. 9 (July 15, 2015): e36-e36. http://dx.doi.org/10.1136/neurintsurg-2015-011784.rep.

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Ruptured arteriovenous malformation (AVM) is a frequent cause of intracranial hemorrhage. The presence of associated aneurysms, especially intranidal aneurysms, is considered to increase the risk of re-hemorrhage. We present two cases where an intranidal aneurysm was demonstrated on four-dimensional CT angiography (time-resolved CT angiography) (4D-CTA). These features were confirmed by digital subtraction angiography (catheter arterial angiogram). This is the first report of an intranidal aneurysm demonstrated by 4D-CTA. 4D-CTA can offer a comprehensive evaluation of the angioarchitecture and flow dynamics of an AVM for appropriate classification and management.

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White, Jordy, Greg Couzens, and Chris Jeffery. "The use of 4D-CT in assessing wrist kinematics and pathology." Bone & Joint Journal 101-B, no. 11 (November 2019): 1325–30. http://dx.doi.org/10.1302/0301-620x.101b11.bjj-2019-0361.r1.

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The wrist is a complex joint involving many small bones and complicated kinematics. It has, therefore, been traditionally difficult to image and ascertain information about kinematics when making a diagnosis. Although MRI and fluoroscopy have been used, they both have limitations. Recently, there has been interest in the use of 4D-CT in imaging the wrist. This review examines the literature regarding the use of 4D-CT in imaging the wrist to assess kinematics and its ability to diagnose pathology. Some questions remain about the description of normal ranges, the most appropriate method of measuring intercarpal stability, the accuracy compared with established standards, and the place of 4D-CT in postoperative assessment. Cite this article: Bone Joint J 2019;101-B:1325–1330.

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Carr, Renee, Simon MacLean, John Slavotinek, and Gregory Bain. "Four-Dimensional Computed Tomography Scanning for Dynamic Wrist Disorders: Prospective Analysis and Recommendations for Clinical Utility." Journal of Wrist Surgery 08, no. 02 (November 14, 2018): 161–67. http://dx.doi.org/10.1055/s-0038-1675564.

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Background Four-dimensional computed tomography (4D CT) is a rapidly developing diagnostic tool in the assessment of dynamic upper limb disorders. Functional wrist anatomy is incompletely understood, and traditional imaging methods are often insufficient in the diagnosis of dynamic disorders. Technique This study has developed a protocol for 4D CT of the wrist, with the aim of reviewing the clinical utility of this technology in surgical assessment. A Toshiba Aquilion One Vision scanner was used in the protocol, in which two- and three-dimensional “static” images, as well as 4D “dynamic” images were produced and assessed in the clinical context of each patient. These consisted of a series of multiple 7-second movement clips exploring the nature and range of joint motion. Patients and Methods Nineteen patients with symptoms of dynamic instability were included in the study. Patients were assessed clinically by two orthopaedic surgeons, and qualitative data were obtained from radiological interpretation. Results The study demonstrated varied abnormalities of joint movement attributed to a range of wrist pathology, including degenerative arthritis, ligamentous injuries, Kienbock's disease, and pain following previous surgical reconstructive procedures. Interpretation of the 4D CT scan changed the clinical diagnosis in 13 cases (68.4%), including the primary (15.8%) or secondary diagnosis (52.6%). In all cases, the assessment of the dynamic wrist motion assisted in understanding the clinical problem and led to a change in management in 11 cases (57.9%). The mean effective radiation dose for the scan was calculated at 0.26 mSv. Conclusion We have found that the clinical utility of 4D CT lies in its ability to provide detailed information about dynamic joint pathology not seen in traditional imaging, targeting surgical treatment. Limitations to the use of 4D CT scan include lack of availability of the technology, potential radiation dose, and radiographer training requirements, as well as limited understanding of the nature of normal motion.

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Wang, Hui, Yong Yin, Hong Jun Wang, and Deng Wang Li. "A New Deformable Image Registration Method Based on B-Spline for Clinical 4D CT." Applied Mechanics and Materials 195-196 (August 2012): 566–71. http://dx.doi.org/10.4028/www.scientific.net/amm.195-196.566.

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Four-dimensional computed tomography (4D CT) which clearly includes the temporal changes in anatomy during the diagnosis, planning, and delivery of radiotherapy has great promise. Deformable image registration has the potential to reduce the geometrical uncertainty of the target, and makes it possible to signally improve the treatment accuracy by optimizing treatment in response to anatomical uncertainty. In this paper, we used Scale Invariant Feature Transform (SIFT) algorithm to extract landmark points, and we proposed a registration method based on B-Spline model, then used a limited memory quasi-Newton method to optimize the system, also calls the limited memory BFGS (L-BFGS) method. The deformable registration model B-Spline model can derive the images at all intermediate phases from sets of 3D images acquired at a few known phase points. Because 4D CT can track the location of region of interest (ROI) and tumors over several respiratory cycles, so 4D CT can make the apparent size of the tumor which is caused by breathing motion more accurate. The method is evaluated on 10 4D-CT data sets of patients in a breathing cycle.

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Wu, Lei, Tao Li, and Qifeng Wang. "Report of four cases of pulmonary malignant tumors treated with SBRT using BODYFIX plus 4D-CBCT image guidance technique." Journal of Clinical Oncology 37, no. 15_suppl (May 20, 2019): e20050-e20050. http://dx.doi.org/10.1200/jco.2019.37.15_suppl.e20050.

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e20050 Background: To monitor the range of motion in SBRT treatment of lung tumors by using BODYFIX combined with four-dimensional cone beam CT (4D-CBCT), and provide evidence for delineating the reasonable internal target area (ITV) of lung cancer, and observe the short-term outcom of treatment and treatment of complications. Methods: 4D-CT was used to locate CT scan, delineate the GTV of the tumor, make a simple radiation treatment planning, determine the treatment center point, and then use line accelerator 4D-CBCT to perform pre-SBRT treatment on 4 patients with lung malignant tumor. The system automatically reconstructs the image and matches the CT image of the treatment plan to obtain the placement error of the patient in the head and foot (SI), left and right (LR), and front and rear (AP) directions. The double registration technique is used to correct the correction first. Positioning error, the 4D-CBCT dynamic image is again registered with the target area, the range of motion within the tumor is observed, and the time-weighted 4D-CBCT image is transmitted back to the Monaco planning system to delineate the target area to accurately determine the range of the ITV. According to this target area, a radiation treatment planning was developed, GTV 20Gy/f, 1 to 3 fractions, and then 4D-CBCT scan was performed in each SBRT treatment to observe the range of tumor motion in real time. Results: 3 of the 4 patients the lung tumors were CR at 3 months after treatment, and 1 patient was SD. No serious complications occurred during the treatment or within 3 months after radiotherapy. Conclusions: The BODYFIX plus 4D-CBCT image can more accurately outline the ITV range of lung cancer. The patient is well tolerated and the short-term outcom is good.

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Helf, Eike, Oliver Waletzko, Christian Mehrens, Ralf Rohn, and Andreas Block. "Impact of 4D CT for treatment planning of moving targets: a computer-based biological evaluation." Current Directions in Biomedical Engineering 3, no. 2 (September 7, 2017): 665–68. http://dx.doi.org/10.1515/cdbme-2017-0140.

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AbstractThis study deals with comparison of conventional and 4D CT (GE Lightspeed) planning on the tumour control probability (TCP), using the TCP model of the AAPM-Report Task Group 166. In the first step a VMAT treatment plan was calculated (Varian Eclipse 13.7) on basis of conventional CT data. This treatment plan was transferred to the complete 4D CT, which represents the tumour volume in motion. Due to the increased volume and the resulting decrease of tumour coverage the TCP went down from 97,6% to 91,2%. After adding an internal target volume (ITV, ICRU 62) to the conventional CT according to our clinical protocols (1,0 cm cc and 0,3 cm axial plane) the TCP increased to 98,0% when applying the conventional plan to the 4D CT. This finding demonstrates the need of 4D CT for moving tumours in chest and abdomen region.Average IPs with increasing width have been created to evaluate the impact on the TCP and the non-malignant tissue. Our observations had shown that heart, lung and spinal cord radiation exposure did not correlate to chosen respiration segment. This could be explained by the extremely slight ratio of the planning target volume and the irradiated normal tissue.This procedure enables us to evaluate the efficacy of treatment plans. Furthermore, optimizing trials like the influence of respiration-gated RT, setting individual margins and fitting planning objectives and parameters are still under investigation.

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Nyflot, M., S. R. Bowen, T. Lee, J. Meyer, G. A. Sandison, and P. E. Kinahan. "Accuracy of 4D Cone Beam CT and 4D Fan Beam CT for Thoracic Radiation Therapy Simulation and Verification Imaging." International Journal of Radiation Oncology*Biology*Physics 90, no. 1 (September 2014): S640. http://dx.doi.org/10.1016/j.ijrobp.2014.05.1897.

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Franken, E., and E. Lefeber. "EP-1727: Low-cost versatile 4D lung phantom for QA of 4D-CT, 4D-CBCT, planning and dosimetry." Radiotherapy and Oncology 127 (April 2018): S923—S924. http://dx.doi.org/10.1016/s0167-8140(18)32036-x.

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Sun, Lixin, Jian Yao, Pan Hao, Yuanyuan Yang, Zhimou Liu, and Ruchen Peng. "Diagnostic Role of Four-Dimensional Computed Tomography for Preoperative Parathyroid Localization in Patients with Primary Hyperparathyroidism: A Systematic Review and Meta-Analysis." Diagnostics 11, no. 4 (April 7, 2021): 664. http://dx.doi.org/10.3390/diagnostics11040664.

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We sought to systematically evaluate diagnostic performance of four-dimensional computed tomography (4D-CT) in the localization of hyperfunctioning parathyroid glands (HPGs) in patients with primary hyperparathyroidism (pHPT). We calculated the pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratios (DOR) of 4D-CT on a per-lesion level, as well as pooled sensitivity and positive predictive value (PPV) on a per-patient level with 95% confidence intervals (CIs). Additionally, we plotted summary receiver operating characteristic (SROC) curves and evaluated the areas under the curves (AUC). A total of 16 studies were included in the analysis. Their pooled sensitivity, specificity, PLR, NLR, and DOR of 4D-CT on per-lesion level were 75% (95%CI: 66–82%), 85% (95%CI: 50–97%), 4.9 (95%CI: 1.1–21.3), 0.30 (95%CI: 0.19–0.45), and 17 (95%CI: 3–100), respectively, with an AUC of 81% (95%CI: 77–84%). We also observed heterogeneity in sensitivity (I2 = 79%) and specificity (I2 = 94.7%), and obtained a pooled sensitivity of 81% (95%CI: 70–90%) with heterogeneity of 81.9% (p < 0.001) and PPV of 91% (95%CI: 82–98%) with heterogeneity of 80.8% (p < 0.001), based on a per-patient level. Overall, 4D-CT showed moderate sensitivity and specificity for preoperative localization of HPG(s) in patients with pHPT. The diagnostic performance may improve with 4D-CT’s promotion to first-line use on a lesion-based level, further research is needed to confirm the results.

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Ipsen, Svenja, Ralf Bruder, Verónica García-Vázquez, Achim Schweikard, and Floris Ernst. "Assessment of 4D Ultrasound Systems for Image-guided Radiation Therapy – Image Quality, Framerates and CT Artifacts." Current Directions in Biomedical Engineering 5, no. 1 (September 1, 2019): 245–48. http://dx.doi.org/10.1515/cdbme-2019-0062.

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Abstract4D ultrasound (4D US) is gaining relevance as a tracking method in radiation therapy (RT) with modern matrix array probes offering new possibilities for real-time target detection. However, for clinical implementation of USguided RT, image quality, volumetric framerate and artifacts caused by the probe’s presence during planning and / or setup computed tomography (CT) must be quantified. We compared three diagnostic 4D US systems with matrix array probes using a commercial wire phantom to measure spatial resolution as well as a calibration and a torso phantom to assess different image quality metrics. CT artifacts were quantified in the torso phantom by calculating the total variation and percentage of affected voxels between a reference CT scan and CT scans with probes in place. We found that state-of-the-art 4D US systems with small probes can fit inside the CT bore and cause fewer metal artifacts than larger probes. US image quality varies between systems and is task-dependent. Volume sizes and framerates are much higher than the commercial guidance solution for US-guided RT, warranting further investigation regarding clinical performance for image guidance.

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Langner, U. W., and P. J. Keall. "Prospective displacement and velocity-based cine 4D CT." Medical Physics 35, no. 10 (September 16, 2008): 4501–12. http://dx.doi.org/10.1118/1.2977539.

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Segars, W. P., M. Mahesh, T. J. Beck, E. C. Frey, and B. M. W. Tsui. "Realistic CT simulation using the 4D XCAT phantom." Medical Physics 35, no. 8 (July 24, 2008): 3800–3808. http://dx.doi.org/10.1118/1.2955743.

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Wink, Nicole, Christoph Panknin, and Timothy D. Solberg. "Phase versus amplitude sorting of 4D-CT data." Journal of Applied Clinical Medical Physics 7, no. 1 (February 15, 2006): 77–85. http://dx.doi.org/10.1120/jacmp.2027.25373.

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Wink, Nicole M., Christoph Panknin, and Timothy D. Solberg. "Phase versus amplitude sorting of 4D-CT data." Journal of Applied Clinical Medical Physics 7, no. 1 (February 21, 2006): 77–85. http://dx.doi.org/10.1120/jacmp.v7i1.2198.

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Boswell, Gilbert, and Kevin Bach. "Cardiac Gated 4D CT for Ectopic Parathyroid Adenoma." Otolaryngology–Head and Neck Surgery 143, no. 2_suppl (August 2010): P179—P180. http://dx.doi.org/10.1016/j.otohns.2010.06.323.

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Van Nieuwenhove, Vincent, Jan De Beenhouwer, Jelle Vlassenbroeck, Mark Brennan, and Jan Sijbers. "MoVIT: a tomographic reconstruction framework for 4D-CT." Optics Express 25, no. 16 (August 1, 2017): 19236. http://dx.doi.org/10.1364/oe.25.019236.

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