SU-FF-I-89: Effects of EPI Slice Angle, Slice Thickness and Phase Encoding Direction On FMRI Sensitivity in Areas with Susceptibility Artifact

2007 ◽  
Vol 34 (6Part4) ◽  
pp. 2358-2358
Author(s):  
SY Cheng ◽  
WC Kuan ◽  
YL Wan ◽  
YY Wai ◽  
HL Liu
2020 ◽  
Vol 336 ◽  
pp. 108625 ◽  
Author(s):  
S.T.M. Duong ◽  
S.L. Phung ◽  
A. Bouzerdoum ◽  
H.G. Boyd Taylor ◽  
A.M. Puckett ◽  
...  

2004 ◽  
Vol 101 (Supplement3) ◽  
pp. 326-333 ◽  
Author(s):  
Klaus D. Hamm ◽  
Gunnar Surber ◽  
Michael Schmücking ◽  
Reinhard E. Wurm ◽  
Rene Aschenbach ◽  
...  

Object. Innovative new software solutions may enable image fusion to produce the desired data superposition for precise target definition and follow-up studies in radiosurgery/stereotactic radiotherapy in patients with intracranial lesions. The aim is to integrate the anatomical and functional information completely into the radiation treatment planning and to achieve an exact comparison for follow-up examinations. Special conditions and advantages of BrainLAB's fully automatic image fusion system are evaluated and described for this purpose. Methods. In 458 patients, the radiation treatment planning and some follow-up studies were performed using an automatic image fusion technique involving the use of different imaging modalities. Each fusion was visually checked and corrected as necessary. The computerized tomography (CT) scans for radiation treatment planning (slice thickness 1.25 mm), as well as stereotactic angiography for arteriovenous malformations, were acquired using head fixation with stereotactic arc or, in the case of stereotactic radiotherapy, with a relocatable stereotactic mask. Different magnetic resonance (MR) imaging sequences (T1, T2, and fluid-attenuated inversion-recovery images) and positron emission tomography (PET) scans were obtained without head fixation. Fusion results and the effects on radiation treatment planning and follow-up studies were analyzed. The precision level of the results of the automatic fusion depended primarily on the image quality, especially the slice thickness and the field homogeneity when using MR images, as well as on patient movement during data acquisition. Fully automated image fusion of different MR, CT, and PET studies was performed for each patient. Only in a few cases was it necessary to correct the fusion manually after visual evaluation. These corrections were minor and did not materially affect treatment planning. High-quality fusion of thin slices of a region of interest with a complete head data set could be performed easily. The target volume for radiation treatment planning could be accurately delineated using multimodal information provided by CT, MR, angiography, and PET studies. The fusion of follow-up image data sets yielded results that could be successfully compared and quantitatively evaluated. Conclusions. Depending on the quality of the originally acquired image, automated image fusion can be a very valuable tool, allowing for fast (∼ 1–2 minute) and precise fusion of all relevant data sets. Fused multimodality imaging improves the target volume definition for radiation treatment planning. High-quality follow-up image data sets should be acquired for image fusion to provide exactly comparable slices and volumetric results that will contribute to quality contol.


2014 ◽  
pp. 159-167
Author(s):  
Huu Thuan Ngo ◽  
Minh Loi Hoang ◽  
Van Dinh Nguyen ◽  
Dinh Duyen Nguyen

Objectives: Imaging characteristis of MDCT in nasopharyngeal carcinoma. Subject and methods: Cross- sectional study in 51patients with nasopharyngeal carcinoma by MDCT at Danang Cancer Hospital from January 2013 to July 2014. Results: The findings reveal that the tumor in lateral wall (66.7%), diameter > 2cm (64.7%), hypodensity (98%), contrast- enhanced CT (62.7%). Blunting of fossa of Rosenmuller (96.1%), invasion of parapharyngeal space (62.7%), destruction of pterygoid bone (19.6%), invasion of skull base (17.6%), destruction of sphenoid bone (9.8%). Lymph nodes metastasis (96.1%), diameter (> 1- 3cm) is 58.8%. T-staging by CT showed T1 (35.3%), T2 (37.3%), T3 (17.6%) and T4 (9.8%). N- staging by CT showed N2 (66.7%), N3a- N3b (19.6%). Staging of Nasopharyngeal carcinoma: stage II-III (60.8%), stage IVA-IVB (23.5%) and stage IVC (11.8%). Conclusions: MDCT with a thinner slice thickness and high quality images is able to detect lymph nodes metastasis with small size and those in deep neck area and assess comprehensively the invasion of the tumor. Key words: Nasopharyngeal carcinoma, MDCT


Author(s):  
Gozde Serindere ◽  
Ceren Aktuna Belgin ◽  
Kaan Orhan

Background: There are a few studies about the evaluation of maxillary first premolars internal structure with micro-computed tomography (micro-CT). The aim of this study was to assess morphological features of the pulp chamber in maxillary first premolar teeth using micro- CT. Methods: Extracted 15 maxillary first premolar teeth were selected from the patients who were in different age groups. The distance between the pulp orifices, the diameter of the pulp and the width of the pulp chamber floor were measured on the micro-CT images with the slice thickness of 13.6 µm. The number of root canal orifices and the presence of isthmus were evaluated. Results: The mean diameter of orifices was 0.73 mm on the buccal side while it was 0.61 mm on palatinal side. The mean distance between pulp orifices was 2.84 mm. The mean angle between pulp orifices was -21.53°. The mean height of pulp orifices on the buccal side was 4.32 mm while the mean height of pulp orifices on the palatinal side was 3.56 mm. The most observed shape of root canal orifices was flattened ribbon. No isthmus was found in specimens. Conclusion: Minor anatomical structures can be evaluated in more detail with micro-CT. The observation of the pulp cavity was analyzed using micro-CT.


2007 ◽  
Vol 42 (3) ◽  
pp. 235-236
Author(s):  
Paul Gluck
Keyword(s):  

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Ninlawan Thammasiri ◽  
Chutimon Thanaboonnipat ◽  
Nan Choisunirachon ◽  
Damri Darawiroj

Abstract Background It is difficult to examine mild to moderate feline intra-thoracic lymphadenopathy via and thoracic radiography. Despite previous information from computed tomographic (CT) images of intra-thoracic lymph nodes, some factors from animals and CT setting were less elucidated. Therefore, this study aimed to investigate the effect of internal factors from animals and external factors from the CT procedure on the feasibility to detect the intra-thoracic lymph nodes. Twenty-four, client-owned, clinically healthy cats were categorized into three groups according to age. They underwent pre- and post-contrast enhanced CT for whole thorax followed by inter-group evaluation and comparison of sternal, cranial mediastinal, and tracheobronchial lymph nodes. Results Post contrast-enhanced CT appearances revealed that intra-thoracic lymph nodes of kittens were invisible, whereas the sternal, cranial mediastinal, and tracheobronchial nodes of cats aged over 7 months old were detected (6/24, 9/24 and 7/24, respectively). Maximum width of these lymph nodes were 3.93 ± 0.74 mm, 4.02 ± 0.65 mm, and 3.51 ± 0.62 mm, respectively. By age, lymph node sizes of these cats were not significantly different. Transverse lymph node width of males was larger than that of females (P = 0.0425). Besides, the detection score of lymph nodes was affected by slice thickness (P < 0.01) and lymph node width (P = 0.0049). Furthermore, an irregular, soft tissue structure, possibly the thymus, was detected in all juvenile cats and three mature cats. Conclusions Despite additional information on intra-thoracic lymph nodes in CT images, which can be used to investigate lymphatic-related abnormalities, age, sex, and slice thickness of CT images must be also considered.


2021 ◽  
Author(s):  
Almir Galvão Vieira Bitencourt ◽  
Vinicius Cardona Felipe ◽  
Mauricio Doi ◽  
Luciana Graziano

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