Imaging and PET - PET/CT imaging

International Nuclear Information System (INIS)

Von Schulthess, G.K.; Hany, Th.F.

2008-01-01

PET/CT has grown because the lack of anatomic landmarks in PET makes 'hardware-fusion' to anatomic cross-sectional data extremely useful. Addition of CT to PET improves specificity, but also sensitivity, and adding PET to CT adds sensitivity and specificity in tumor imaging. The synergistic advantage of adding CT is that the attenuation correction needed for PET data can also be derived from the CT data. This makes PET-CT 25-30% faster than PET alone, leading to higher patient throughput and a more comfortable examination for patients typically lasting 20 minutes or less. FDG-PET-CT appears to provide relevant information in the staging and therapy monitoring of many tumors, such as lung carcinoma, colorectal cancer, lymphoma, gynaecological cancers, melanoma and many others, with the notable exception of prostatic cancer. for this cancer, choline derivatives may possibly become useful radiopharmaceuticals. The published literature on the applications of FDG-PET-CT in oncology is still limited but several designed studies have demonstrated the benefits of PET-CT. (authors)

Automated assessment of bone changes in cross-sectional micro-CT studies of murine experimental osteoarthritis.

Science.gov (United States)

Das Neves Borges, Patricia; Vincent, Tonia L; Marenzana, Massimo

2017-01-01

The degradation of articular cartilage, which characterises osteoarthritis (OA), is usually paired with excessive bone remodelling, including subchondral bone sclerosis, cysts, and osteophyte formation. Experimental models of OA are widely used to investigate pathogenesis, yet few validated methodologies for assessing periarticular bone morphology exist and quantitative measurements are limited by manual segmentation of micro-CT scans. The aim of this work was to chart the temporal changes in periarticular bone in murine OA by novel, automated micro-CT methods. OA was induced by destabilisation of the medial meniscus (DMM) in 10-week old male mice and disease assessed cross-sectionally from 1- to 20-weeks post-surgery. A novel approach was developed to automatically segment subchondral bone compartments into plate and trabecular bone in micro-CT scans of tibial epiphyses. Osteophyte volume, as assessed by shape differences using 3D image registration, and by measuring total epiphyseal volume was performed. Significant linear and volumetric structural modifications in subchondral bone compartments and osteophytes were measured from 4-weeks post-surgery and showed progressive changes at all time points; by 20 weeks, medial subchondral bone plate thickness increased by 160±19.5 μm and the medial osteophyte grew by 0.124±0.028 μm3. Excellent agreement was found when automated measurements were compared with manual assessments. Our automated methods for assessing bone changes in murine periarticular bone are rapid, quantitative, and highly accurate, and promise to be a useful tool in future preclinical studies of OA progression and treatment. The current approaches were developed specifically for cross-sectional micro-CT studies but could be applied to longitudinal studies.

Automated assessment of bone changes in cross-sectional micro-CT studies of murine experimental osteoarthritis.

Directory of Open Access Journals (Sweden)

Patricia Das Neves Borges

Full Text Available The degradation of articular cartilage, which characterises osteoarthritis (OA, is usually paired with excessive bone remodelling, including subchondral bone sclerosis, cysts, and osteophyte formation. Experimental models of OA are widely used to investigate pathogenesis, yet few validated methodologies for assessing periarticular bone morphology exist and quantitative measurements are limited by manual segmentation of micro-CT scans. The aim of this work was to chart the temporal changes in periarticular bone in murine OA by novel, automated micro-CT methods.OA was induced by destabilisation of the medial meniscus (DMM in 10-week old male mice and disease assessed cross-sectionally from 1- to 20-weeks post-surgery. A novel approach was developed to automatically segment subchondral bone compartments into plate and trabecular bone in micro-CT scans of tibial epiphyses. Osteophyte volume, as assessed by shape differences using 3D image registration, and by measuring total epiphyseal volume was performed.Significant linear and volumetric structural modifications in subchondral bone compartments and osteophytes were measured from 4-weeks post-surgery and showed progressive changes at all time points; by 20 weeks, medial subchondral bone plate thickness increased by 160±19.5 μm and the medial osteophyte grew by 0.124±0.028 μm3. Excellent agreement was found when automated measurements were compared with manual assessments.Our automated methods for assessing bone changes in murine periarticular bone are rapid, quantitative, and highly accurate, and promise to be a useful tool in future preclinical studies of OA progression and treatment. The current approaches were developed specifically for cross-sectional micro-CT studies but could be applied to longitudinal studies.

Cross-Sectional Transport Imaging in a Multijunction Solar Cell

Energy Technology Data Exchange (ETDEWEB)

Haegel, Nancy M.; Ke, Chi-Wen; Taha, Hesham; Guthrey, Harvey; Fetzer, C. M.; King, Richard

2015-06-14

Combining highly localized electron-beam excitation at a point with the spatial resolution capability of optical near-field imaging, we have imaged carrier transport in a cross-sectioned multijunction (GaInP/GaInAs/Ge) solar cell. We image energy transport associated with carrier diffusion throughout the full width of the middle (GaInAs) cell and luminescent coupling from point excitation in the top cell GaInP to the middle cell. Supporting cathodoluminescence and near-field photoluminescence measurements demonstrate excitation-dependent Fermi level splitting effects that influence cross-sectioned spectroscopy results as well as transport limitations on the spatial resolution of cross-sectional measurements.

Visibility of the mandibular canal on cross-sectional CBCT images at impacted mandibular third molar sites

International Nuclear Information System (INIS)

Alkhader, Mustafa; Jarab, Fadi

2016-01-01

The aim of the present study was to assess visibility of the mandibular canal (MC) on cross-sectional cone beam CT (CBCT) images at impacted mandibular third molar (IMTM) sites. CBCT images for 150 IMTMs were selected for the study. The type of tooth impaction (horizontal, vertical, mesial and distal) and location of the MC (inferior in contact and superimposed) were evaluated on pseudo panoramic images. Cross-sectional images were generated and two observers evaluated the location of the MC (buccal, lingual, inter-radicular and inferior) and its visibility using 3-point scoring scale: (1-3, good-excellent). Kruskal-Wallis test was used to examine the differences in the visibility of the MC according to its location and the type of tooth impaction. The visibility scores of the MC were good, very good and excellent at 3, 25 and 122 IMTM sites, respectively. There were no statistically significant differences in the visibility scores of the MC according to its location or the type of tooth impaction (P < 0.05). Therefore, despite the different locations of the MC and different types of tooth impaction at IMTM sites, the visibility of the MC was excellent on most of the cross-sectional CBCT images. CBCT is considered a valuable diagnostic tool for achieving these results

Computed Tomography (CT) -- Head

Medline Plus

Full Text Available ... images or pictures of the inside of the body. The cross-sectional images generated during a CT scan can be reformatted ... of data to create two-dimensional cross-sectional images of your body, which are then displayed on a monitor. CT ...

Computed Tomography (CT) -- Sinuses

Medline Plus

Full Text Available ... images or pictures of the inside of the body. The cross-sectional images generated during a CT scan can be reformatted ... of data to create two-dimensional cross-sectional images of your body, which are then displayed on a monitor. CT ...

Abdominal and Pelvic CT

Medline Plus

Full Text Available ... images or pictures of the inside of the body. The cross-sectional images generated during a CT scan can be reformatted ... of data to create two-dimensional cross-sectional images of your body, which are then displayed on a monitor. CT ...

Leiomyosarcomas of the inferior vena cava: diagnostic features on cross-sectional imaging

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Ganeshalingam, S., E-mail: skandadas.ganeshalingam@nhs.ne [Department of Clinical Radiology, The Royal Marsden NHS Foundation Trust, London (United Kingdom); Rajeswaran, G. [Department of Clinical Radiology, The Royal Marsden NHS Foundation Trust, London (United Kingdom); Jones, R.L. [Department of Clinical Oncology, University of Washington and Hutchinson Cancer Research Center, Seattle, WA (United States); Thway, K. [Department of Histopathology, The Royal Marsden NHS Foundation Trust, London (United Kingdom); Moskovic, E. [Department of Clinical Radiology, The Royal Marsden NHS Foundation Trust, London (United Kingdom)

2011-01-15

Aim: To evaluate the cross-sectional radiological appearances and to review the clinical presentation and outcome of patients with leiomyosarcomas of the inferior vena cava (IVC LMS). These are rare aggressive tumours that present late with non-specific symptoms and have a poor prognosis. Materials and Methods: From January 2002 to December 2008, the radiological images of 23 sequential patients with pathologically proven IVC LMS were independently reviewed by two experienced radiologists. The clinical presentation, treatment including surgical details, and outcome were recorded. Results: There were 19 females and four males with a mean age of 53 years. CT typically demonstrated a large, lobulate, non-calcified heterogeneous mass with peripheral enhancement. T1-weighted magnetic resonance imaging (MRI) images demonstrated a mass with a low signal intensity and T2-weighted MRI images demonstrated a mass with a high signal intensity. Clinical presentation included leg oedema, back and abdominal pain with almost 50% of patients presenting with metastases. Eleven patients underwent ablative surgery. The mean survival time of all patients in the study was 34 months and that of the 11 post-surgical patients was 56 months. Conclusion: There are a variety of diagnostic features on both computed tomography (CT) and MRI which aid the diagnosis of this unusual vascular neoplasm. CT is vital in determining the location of the tumour within the IVC and MRI accurately depicts its extent and the potential for surgical resectability, which offers the only chance of survival.

Leiomyosarcomas of the inferior vena cava: diagnostic features on cross-sectional imaging

International Nuclear Information System (INIS)

Ganeshalingam, S.; Rajeswaran, G.; Jones, R.L.; Thway, K.; Moskovic, E.

2011-01-01

Aim: To evaluate the cross-sectional radiological appearances and to review the clinical presentation and outcome of patients with leiomyosarcomas of the inferior vena cava (IVC LMS). These are rare aggressive tumours that present late with non-specific symptoms and have a poor prognosis. Materials and Methods: From January 2002 to December 2008, the radiological images of 23 sequential patients with pathologically proven IVC LMS were independently reviewed by two experienced radiologists. The clinical presentation, treatment including surgical details, and outcome were recorded. Results: There were 19 females and four males with a mean age of 53 years. CT typically demonstrated a large, lobulate, non-calcified heterogeneous mass with peripheral enhancement. T1-weighted magnetic resonance imaging (MRI) images demonstrated a mass with a low signal intensity and T2-weighted MRI images demonstrated a mass with a high signal intensity. Clinical presentation included leg oedema, back and abdominal pain with almost 50% of patients presenting with metastases. Eleven patients underwent ablative surgery. The mean survival time of all patients in the study was 34 months and that of the 11 post-surgical patients was 56 months. Conclusion: There are a variety of diagnostic features on both computed tomography (CT) and MRI which aid the diagnosis of this unusual vascular neoplasm. CT is vital in determining the location of the tumour within the IVC and MRI accurately depicts its extent and the potential for surgical resectability, which offers the only chance of survival.

3D Interpolation Method for CT Images of the Lung

Directory of Open Access Journals (Sweden)

Noriaki Asada

2003-06-01

Full Text Available A 3-D image can be reconstructed from numerous CT images of the lung. The procedure reconstructs a solid from multiple cross section images, which are collected during pulsation of the heart. Thus the motion of the heart is a special factor that must be taken into consideration during reconstruction. The lung exhibits a repeating transformation synchronized to the beating of the heart as an elastic body. There are discontinuities among neighboring CT images due to the beating of the heart, if no special techniques are used in taking CT images. The 3-D heart image is reconstructed from numerous CT images in which both the heart and the lung are taken. Although the outline shape of the reconstructed 3-D heart is quite unnatural, the envelope of the 3-D unnatural heart is fit to the shape of the standard heart. The envelopes of the lung in the CT images are calculated after the section images of the best fitting standard heart are located at the same positions of the CT images. Thus the CT images are geometrically transformed to the optimal CT images fitting best to the standard heart. Since correct transformation of images is required, an Area oriented interpolation method proposed by us is used for interpolation of transformed images. An attempt to reconstruct a 3-D lung image by a series of such operations without discontinuity is shown. Additionally, the same geometrical transformation method to the original projection images is proposed as a more advanced method.

Analyses of the eustachian tube and its surrounding tissues with cross sectional images by high-resolution computed tomography (HR-CT)

International Nuclear Information System (INIS)

Yoshida, Haruo; Kobayashi, Toshimitsu; Takasaki, Kenji; Kanda, Yukihiko; Nakao, Yoshiaki; Morikawa, Minoru; Ishimaru, Hideki; Hayashi, Kuniaki

2000-01-01

We attempted to image the eustachian tube (ET) and its surrounding tissues by high-resolution computed tomography (HR-CT). Twenty-two normal subjects (44 ears) without middle ear problems were studied, and a patient with severe patulous ET was also studied as an abnormal case. In our device of multiplanar reconstruction technique, we were able to obtain the clear reconstructed images of the ET lumen as well as of its surrounding tissues (bone, ET cartilage, tensor veli palatini muscle, levator veli palatini muscle, Ostmann's fat tissue, tensor tympani muscle, internal carotid artery) at any desired portion, either parallel or perpendicular to the long axis of the ET. However, the exact borders between the ET cartilage and the muscles, Ostmann's fat tissue and the tubal gland were not clearly identified. In the severe case of patulous ET, the ET lumen was widely opened at each cross-sectional image from the pharyngeal orifice to the tympanic orifice, in contrast with its being closed at the cartilaginous portion in the normal cases. In addition, the fat tissue and glands around the ET lumen were not clearly identified in this case. We suggest that this method will lead to better understanding of the ET-related diseases such as patulous ET. (author)

Analyses of the eustachian tube and its surrounding tissues with cross sectional images by high-resolution computed tomography (HR-CT)

Energy Technology Data Exchange (ETDEWEB)

Yoshida, Haruo; Kobayashi, Toshimitsu; Takasaki, Kenji; Kanda, Yukihiko; Nakao, Yoshiaki; Morikawa, Minoru; Ishimaru, Hideki; Hayashi, Kuniaki [Nagasaki Univ. (Japan). School of Medicine

2000-07-01

We attempted to image the eustachian tube (ET) and its surrounding tissues by high-resolution computed tomography (HR-CT). Twenty-two normal subjects (44 ears) without middle ear problems were studied, and a patient with severe patulous ET was also studied as an abnormal case. In our device of multiplanar reconstruction technique, we were able to obtain the clear reconstructed images of the ET lumen as well as of its surrounding tissues (bone, ET cartilage, tensor veli palatini muscle, levator veli palatini muscle, Ostmann's fat tissue, tensor tympani muscle, internal carotid artery) at any desired portion, either parallel or perpendicular to the long axis of the ET. However, the exact borders between the ET cartilage and the muscles, Ostmann's fat tissue and the tubal gland were not clearly identified. In the severe case of patulous ET, the ET lumen was widely opened at each cross-sectional image from the pharyngeal orifice to the tympanic orifice, in contrast with its being closed at the cartilaginous portion in the normal cases. In addition, the fat tissue and glands around the ET lumen were not clearly identified in this case. We suggest that this method will lead to better understanding of the ET-related diseases such as patulous ET. (author)

Imaging of female pelvic malignancies regarding MRI, CT, and PET/CT. Pt. 2

International Nuclear Information System (INIS)

Alt, Celine D.; Kauczor, Hans-Ulrich; Hallscheidt, Peter; Brocker, Kerstin A.; Eichbaum, Michael; Sohn, Christof; Arnegger, Florian U.

2011-01-01

To compose diagnostic standard operating procedures for both clinical and imaging assessment for vulvar and vaginal cancer, for vaginal sarcoma, and for ovarian cancer. The literature was reviewed for diagnosing the above mentioned malignancies in the female pelvis. Special focus herein lies in tumor representation in MRI, followed by the evaluation of CT and PET/CT for this topic. MRI is a useful additional diagnostic complement but by no means replaces established methods of gynecologic diagnostics and ultrasound. In fact, MRI is only implemented in the guidelines for vulvar cancer. According to the current literature, CT is still the cross-sectional imaging modality of choice for evaluating ovarian cancer. PET/CT appears to have advantages for staging and follow-up in sarcomas and cancers of the ovaries. (orig.)

CT and MRI techniques for imaging around orthopedic hardware

Energy Technology Data Exchange (ETDEWEB)

Do, Thuy Duong; Skornitzke, Stephan; Weber, Marc-Andre [Heidelberg Univ. (Germany). Dept. of Clinical Radiology; Sutter, Reto [Uniklinik Balgrist, Zurich (Switzerland). Radiology

2018-01-15

Orthopedic hardware impairs image quality in cross-sectional imaging. With an increasing number of orthopedic implants in an aging population, the need to mitigate metal artifacts in computed tomography and magnetic resonance imaging is becoming increasingly relevant. This review provides an overview of the major artifacts in CT and MRI and state-of-the-art solutions to improve image quality. All steps of image acquisition from device selection, scan preparations and parameters to image post-processing influence the magnitude of metal artifacts. Technological advances like dual-energy CT with the possibility of virtual monochromatic imaging (VMI) and new materials offer opportunities to further reduce artifacts in CT and MRI. Dedicated metal artifact reduction sequences contain algorithms to reduce artifacts and improve imaging of surrounding tissue and are essential tools in orthopedic imaging to detect postoperative complications in early stages.

Computed tomographic and cross-sectional anatomy of the normal pacu (Colossoma macroponum).

Science.gov (United States)

Carr, Alaina; Weber, E P Scott; Murphy, Chris J; Zwingenberger, Alison

2014-03-01

The purpose of this study was to compare and define the normal cross-sectional gross and computed tomographic (CT) anatomy for a species of boney fish to better gain insight into the use of advanced diagnostic imaging for future clinical cases. The pacu (Colossoma macropomum) was used because of its widespread presence in the aquarium trade, its relatively large body size, and its importance in the research and aquaculture settings. Transverse 0.6-mm CT images of three cadaver fish were obtained and compared to corresponding frozen cross sections of the fish. Relevant anatomic structures were identified and labeled at each level; the Hounsfield unit density of major organs was established. The images presented good anatomic detail and provide a reference for future research and clinical investigation.

CT-based postimplant dosimetry of prostate brachytherapy. Comparison of 1-mm and 5-mm section CT

International Nuclear Information System (INIS)

Tanaka, Osamu; Hayashi, Shinya; Kanematsu, Masayuki; Matsuo, Masayuki; Hoshi, Hiroaki; Nakano, Masahiro; Maeda, Sanaho; Deguchi, Takashi; Hoshi, Hiroaki

2007-01-01

The aim of this study was to compare the outcomes between 1-mm and 5-mm section computed tomography (CT)-based postimplant dosimetry. A series of 21 consecutive patients underwent permanent prostate brachytherapy. The postimplant prostate volume was calculated using 1-mm and 5-mm section CT. One radiation oncologist contoured the prostate on CT images to obtain the reconstructed prostate volume (pVol), prostate V 100 (percent of the prostate volume receiving at least the full prescribed dose), and prostate D 90 (mean dose delivered to 90% of the prostate gland). The same radiation oncologist performed the contouring three times to evaluate intraobserver variation and subjectively scored the quality of the CT images. The mean ±1 standard deviation (SD) postimplant pVol was 20.17±6.66 cc by 1-mm section CT and 22.24±8.48 cc by 5-mm section CT; the difference in the mean values was 2.06 cc (P 100 was 80.44%±7.06% by 1-mm section CT and 77.33%±10.22% by 5-mm section CT. The mean postimplant prostate D 90 was 83.28%±10.81% by 1-mm section CT and 78.60%±15.75% by 5-mm section CT. In the evaluation of image quality, 5-mm section CT was assigned significantly higher scores than 1-mm section CT. In regard to intraobserver variation, 5-mm section CT revealed less intraobserver variation than 1-mm section CT. Our current results suggested that the outcomes of postimplant dosimetry using 1-mm section CT did not improved the results over those obtained using 5-mm section CT in terms of the quality of the CT image or reproducibility. (author)

Automatic segmentation of liver structure in CT images

International Nuclear Information System (INIS)

Bae, K.T.; Giger, M.L.; Chen, C.; Kahn, C.E. Jr.

1993-01-01

The segmentation and three-dimensional representation of the liver from a computed tomography (CT) scan is an important step in many medical applications, such as in the surgical planning for a living-donor liver transplant and in the automatic detection and documentation of pathological states. A method is being developed to automatically extract liver structure from abdominal CT scans using a priori information about liver morphology and digital image-processing techniques. Segmentation is performed sequentially image-by-image (slice-by-slice), starting with a reference image in which the liver occupies almost the entire right half of the abdomen cross section. Image processing techniques include gray-level thresholding, Gaussian smoothing, and eight-point connectivity tracking. For each case, the shape, size, and pixel density distribution of the liver are recorded for each CT image and used in the processing of other CT images. Extracted boundaries of the liver are smoothed using mathematical morphology techniques and B-splines. Computer-determined boundaries were compared with those drawn by a radiologist. The boundary descriptions from the two methods were in agreement, and the calculated areas were within 10%

Reversing the established order: Should adrenal venous sampling precede cross-sectional imaging in the evaluation of primary aldosteronism?

Science.gov (United States)

Asmar, Melissa; Wachtel, Heather; Yan, Yan; Fraker, Douglas L; Cohen, Debbie; Trerotola, Scott O

2015-08-01

Adrenal venous sampling (AVS) is the definitive evaluation for primary aldosteronism (PA). Pre-AVS cross-sectional imaging does not reduce the need for AVS. The goal of this study was to examine whether performing AVS prior to imaging could decrease the use of imaging in the evaluation of PA at a high volume, experienced center. We performed a retrospective analysis of all AVS procedures (n = 337) done for PA from 2001-2013. Patients whose cross-sectional imaging reports were unavailable (n = 90) or AVS was non-diagnostic (n = 12) were excluded. AVS was performed using modified Mayo technique. Univariate analysis utilized the χ² test and fisher's exact test. Of the 235 patients analyzed, 63% (n = 148) were male. The mean age was 55 ± 11 years. AVS was non-lateralizing in 43% (n = 101); these patients might have avoided imaging with an AVS-first approach. Imaging and AVS were concordant in 52% (n = 123). In patients ≤40yo (n = 23), 35% (n = 8) had no lateralization on AVS, and might have avoided imaging in an AVS-first approach. Imaging and AVS were concordant in 52% (n = 12) of patients ≤ 40yo, versus 52% (n = 111) of patients > 40 yo (P = 0.987). An AVS-first, imaging-second approach could have avoided CT/MRI in 43% of patients. At a high volume, experienced center, performing AVS first on patients with PA may reduce unnecessary cross-sectional imaging studies. © 2015 Wiley Periodicals, Inc.

Three-section expiratory CT

DEFF Research Database (Denmark)

Loeve, Martine; de Bruijne, Marleen; Hartmann, Ieneke C. J.

2012-01-01

. Longitudinal follow-up was performed with three sections. All images were deidentified and randomized, and TA was scored with the Brody II system and a new quantitative system. Statistical analysis included the Wilcoxon signed rank test, calculation of Spearman and intraclass correlation coefficients, and use......Purpose: To estimate the effect of the number of computed tomography (CT) sections on trapped air (TA) assessment in patients with cystic fibrosis (CF) by using an established scoring system and a new quantitative scoring system and to compare CT and pulmonary function test (PFT) estimates of TA...

Integrated image presentation of transmission and fluorescent X-ray CT using synchrotron radiation

Energy Technology Data Exchange (ETDEWEB)

Zeniya, T.; Takeda, T. E-mail: ttakeda@md.tsukuba.ac.jp; Yu, Q.; Hasegawa, Y.; Hyodo, K.; Yuasa, T.; Hiranaka, Y.; Itai, Y.; Akatsuka, T

2001-07-21

We have developed a computed tomography (CT) system with synchrotron radiation (SR) to detect fluorescent X-rays and transmitted X-rays simultaneously. Both SR transmission X-ray CT (SR-TXCT) and SR fluorescent X-ray CT (SR-FXCT) can describe cross-sectional images with high spatial and contrast resolutions as compared to conventional CT. TXCT gives morphological information and FXCT gives functional information of organs. So, superposed display system for SR-FXCT and SR-TXCT images has been developed for clinical diagnosis with higher reliability. Preliminary experiment with brain phantom was carried out and the superposition of both images was performed. The superposed SR-CT image gave us both functional and morphological information easily with high reliability, thus demonstrating the usefulness of this system.

Integrated image presentation of transmission and fluorescent X-ray CT using synchrotron radiation

Science.gov (United States)

Zeniya, T.; Takeda, T.; Yu, Q.; Hasegawa, Y.; Hyodo, K.; Yuasa, T.; Hiranaka, Y.; Itai, Y.; Akatsuka, T.

2001-07-01

We have developed a computed tomography (CT) system with synchrotron radiation (SR) to detect fluorescent X-rays and transmitted X-rays simultaneously. Both SR transmission X-ray CT (SR-TXCT) and SR fluorescent X-ray CT (SR-FXCT) can describe cross-sectional images with high spatial and contrast resolutions as compared to conventional CT. TXCT gives morphological information and FXCT gives functional information of organs. So, superposed display system for SR-FXCT and SR-TXCT images has been developed for clinical diagnosis with higher reliability. Preliminary experiment with brain phantom was carried out and the superposition of both images was performed. The superposed SR-CT image gave us both functional and morphological information easily with high reliability, thus demonstrating the usefulness of this system.

Sectional depiction of the pelvic floor by CT, MR imaging and sheet plastination: computer-aided correlation and 3D model

Energy Technology Data Exchange (ETDEWEB)

Beyersdorff, D.; Taupitz, M.; Hamm, B. [Dept. of Radiology, Humboldt Univ., Berlin (Germany); Schiemann, T. [Inst. for Mathematics and Computer Science in Medicine, University of Hamburg (Germany); Kooijman, H. [Philips Medical Systems, Hamburg (Germany); Nicolas, V. [Dept. of Radiology and Nuclear Medicine, BG Kliniken Bergmannsheil, Bochum (Germany)

2001-04-01

The structures of the pelvic floor are clinically important but difficult to assess. To facilitate the understanding of the complicated pelvic floor anatomy on sectional images obtained by CT and MR imaging, and to make the representation more vivid, a computer-aided 3D model was created from a male and a female torso to develop a teaching tool. A male and a female cadaver torso were investigated by means of CT, MR imaging, and serial-section sheet plastination. A 3D reconstruction of the pelvic floor and adjacent structures was performed by fusion of CT and MR imaging data sets with sheet plastination sections. Corresponding sections from all three methods could be compared and visualized in their 3D context. Sheet plastination allows distinction of connective tissue, muscles, and pelvic organs down to a microscopic level. In combination with CT, MR imaging, and sheet plastination a 3D model of the pelvic floor offers a better understanding of the complex pelvic anatomy. This knowledge may be applied in the diagnostic imaging of urinary incontinence or prolapse and prior to prostate surgery. (orig.)

A Rare Presentation of Lymphoma of the Cervix with Cross-Sectional Imaging Correlation

Directory of Open Access Journals (Sweden)

Brinda Rao Korivi

2014-01-01

Full Text Available Non-Hodgkin’s lymphoma of the cervix is an extremely uncommon entity, with no standard established treatment protocol. A 43-year-old asymptomatic female with a history of dual hit blastic B-cell lymphoma/leukemia in complete remission presented with an incidental cervical mass, which was initially felt to represent a cervical fibroid on computed tomography (CT. It was further evaluated with ultrasound, biopsy, and positron emission tomography-computed tomography (PET-CT, which demonstrated a growing biopsy-proven lymphomatous mass and new humeral head lesion. The patient was started on chemotherapy to control the newly diagnosed humeral head lesion, which then regressed. She then underwent radiation to the cervix with significant improvement in the cervical lymphoma. A review of cross-sectional imaging findings of lymphoma of the cervix is provided, including how to differentiate it from other more common diseases of the cervix. Clinical awareness of rare cervical masses such as lymphoma is very important in order to achieve timely diagnosis and appropriate treatment.

Coronary Stent Artifact Reduction with an Edge-Enhancing Reconstruction Kernel - A Prospective Cross-Sectional Study with 256-Slice CT.

Science.gov (United States)

Tan, Stéphanie; Soulez, Gilles; Diez Martinez, Patricia; Larrivée, Sandra; Stevens, Louis-Mathieu; Goussard, Yves; Mansour, Samer; Chartrand-Lefebvre, Carl

2016-01-01

Metallic artifacts can result in an artificial thickening of the coronary stent wall which can significantly impair computed tomography (CT) imaging in patients with coronary stents. The objective of this study is to assess in vivo visualization of coronary stent wall and lumen with an edge-enhancing CT reconstruction kernel, as compared to a standard kernel. This is a prospective cross-sectional study involving the assessment of 71 coronary stents (24 patients), with blinded observers. After 256-slice CT angiography, image reconstruction was done with medium-smooth and edge-enhancing kernels. Stent wall thickness was measured with both orthogonal and circumference methods, averaging thickness from diameter and circumference measurements, respectively. Image quality was assessed quantitatively using objective parameters (noise, signal to noise (SNR) and contrast to noise (CNR) ratios), as well as visually using a 5-point Likert scale. Stent wall thickness was decreased with the edge-enhancing kernel in comparison to the standard kernel, either with the orthogonal (0.97 ± 0.02 versus 1.09 ± 0.03 mm, respectively; pkernel generated less overestimation from nominal thickness compared to the standard kernel, both with the orthogonal (0.89 ± 0.19 versus 1.00 ± 0.26 mm, respectively; pkernel was associated with lower SNR and CNR, as well as higher background noise (all p kernel. Stent visual scores were higher with the edge-enhancing kernel (pkernel generates thinner stent walls, less overestimation from nominal thickness, and better image quality scores than the standard kernel.

Cross-sectional imaging to evaluate the extent of regional nodal disease in breast cancer patients undergoing neoadjuvant systemic therapy

Energy Technology Data Exchange (ETDEWEB)

Anderson, Tara L., E-mail: anderson.tara@mayo.edu [Mayo Clinic, Department of Radiology, 200 First Street SW, Rochester, MN, 55905 (United States); Glazebrook, Katrina N., E-mail: glazebrook.katrina@mayo.edu [Mayo Clinic, Department of Radiology, 200 First Street SW, Rochester, MN, 55905 (United States); Murphy, Brittany L., E-mail: murphy.brittany@mayo.edu [Mayo Clinic, Department of Surgery, 200 First Street SW, Rochester, MN, 55905 (United States); Viers, Lyndsay D., E-mail: viers.lyndsay@mayo.edu [Mayo Clinic, Department of Radiology, 200 First Street SW, Rochester, MN, 55905 (United States); Hieken, Tina J, E-mail: hieken.tina@mayo.edu [Mayo Clinic, Department of Surgery, 200 First Street SW, Rochester, MN, 55905 (United States)

2017-04-15

Purpose: Cross-sectional imaging often is performed in breast cancer patients undergoing neoadjuvant systemic therapy (NST) and may identify level III axillary and extra-axillary nodal disease. Our aim was to investigate associations of radiologic nodal staging with pathological N (pN) stage at operation and to explore how this might aid surgical and radiotherapy treatment planning. Materials and methods: With IRB approval, we reviewed pre-treatment breast MRI, PET/CT, and CT imaging and clinicopathologic data on 348 breast cancer patients with imaging available for review undergoing NST followed by operation at our institution 1/2008-9/2013. We defined abnormal lymph node findings on MRI, CT, and PET/CT to include cortical thickening, FDG-avidity and loss of fatty hilum. Patients were assigned a radiologic nodal (rN) stage based on imaging findings. Statistical analysis was performed using JMP 10.1 software Results: Pre-NST imaging included axillary ultrasound in 338 patients (97%), breast MRI in 305 (88%) and PET/CT or CT in 215 (62%). 213 patients (61%) were biopsy-proven axillary lymph node-positive (LN+) pre-treatment. cT stage was T1 in 9%, T2 in 49%, T3 in 29%, T4 in 12%; median tumor size was 4 cm. Pre-treatment rN stage across all the patients was rN0 in 86 (25%), rN1 in 173 (50%), and rN3 in 89 (26%). rN3 disease included level III axillary, supraclavicular and suspicious internal mammary lymph nodes in 47 (53%), 32 (37%) and 45 (52%), respectively. Of patients LN+ at diagnosis, 78 (37%) were rN3. After NST, 162 patients (47%) were node-positive at operation with a median (mean) of 3 (5.9 ± 0.4) positive lymph nodes including 128 of 213 (60%) LN+ at diagnosis. Pre-NST rN stage correlated with the likelihood and extent of axillary disease at operation, p = 0.002. Fifty four of 89 rN3 patients (61%) were node-positive at operation with a median (mean) of 5 (8 ± 1) positive nodes. rN3 patients had larger nodal metastases (median 9 vs 6 mm) and more

Cross-sectional imaging to evaluate the extent of regional nodal disease in breast cancer patients undergoing neoadjuvant systemic therapy

International Nuclear Information System (INIS)

Anderson, Tara L.; Glazebrook, Katrina N.; Murphy, Brittany L.; Viers, Lyndsay D.; Hieken, Tina J

2017-01-01

Purpose: Cross-sectional imaging often is performed in breast cancer patients undergoing neoadjuvant systemic therapy (NST) and may identify level III axillary and extra-axillary nodal disease. Our aim was to investigate associations of radiologic nodal staging with pathological N (pN) stage at operation and to explore how this might aid surgical and radiotherapy treatment planning. Materials and methods: With IRB approval, we reviewed pre-treatment breast MRI, PET/CT, and CT imaging and clinicopathologic data on 348 breast cancer patients with imaging available for review undergoing NST followed by operation at our institution 1/2008-9/2013. We defined abnormal lymph node findings on MRI, CT, and PET/CT to include cortical thickening, FDG-avidity and loss of fatty hilum. Patients were assigned a radiologic nodal (rN) stage based on imaging findings. Statistical analysis was performed using JMP 10.1 software Results: Pre-NST imaging included axillary ultrasound in 338 patients (97%), breast MRI in 305 (88%) and PET/CT or CT in 215 (62%). 213 patients (61%) were biopsy-proven axillary lymph node-positive (LN+) pre-treatment. cT stage was T1 in 9%, T2 in 49%, T3 in 29%, T4 in 12%; median tumor size was 4 cm. Pre-treatment rN stage across all the patients was rN0 in 86 (25%), rN1 in 173 (50%), and rN3 in 89 (26%). rN3 disease included level III axillary, supraclavicular and suspicious internal mammary lymph nodes in 47 (53%), 32 (37%) and 45 (52%), respectively. Of patients LN+ at diagnosis, 78 (37%) were rN3. After NST, 162 patients (47%) were node-positive at operation with a median (mean) of 3 (5.9 ± 0.4) positive lymph nodes including 128 of 213 (60%) LN+ at diagnosis. Pre-NST rN stage correlated with the likelihood and extent of axillary disease at operation, p = 0.002. Fifty four of 89 rN3 patients (61%) were node-positive at operation with a median (mean) of 5 (8 ± 1) positive nodes. rN3 patients had larger nodal metastases (median 9 vs 6 mm) and more

Pulmonary function-morphologic relationships assessed by SPECT-CT fusion images

International Nuclear Information System (INIS)

Suga, Kazuyoshi

2012-01-01

Pulmonary single photon emission computed tomography-computed tomography (SPECT-CT) fusion images provide objective and comprehensive assessment of pulmonary function and morphology relationships at cross-sectional lungs. This article reviewed the noteworthy findings of lung pathophysiology in wide-spectral lung disorders, which have been revealed on SPECT-CT fusion images in 8 years of experience. The fusion images confirmed the fundamental pathophysiologic appearance of lung low CT attenuation caused by airway obstruction-induced hypoxic vasoconstriction and that caused by direct pulmonary arterial obstruction as in acute pulmonary thromboembolism (PTE). The fusion images showed better correlation of lung perfusion distribution with lung CT attenuation changes at lung mosaic CT attenuation (MCA) compared with regional ventilation in the wide-spectral lung disorders, indicating that lung heterogeneous perfusion distribution may be a dominant mechanism of MCA on CT. SPECT-CT angiography fusion images revealed occasional dissociation between lung perfusion defects and intravascular clots in acute PTE, indicating the importance of assessment of actual effect of intravascular colts on peripheral lung perfusion. Perfusion SPECT-CT fusion images revealed the characteristic and preferential location of pulmonary infarction in acute PTE. The fusion images showed occasional unexpected perfusion defects in normal lung areas on CT in chronic obstructive pulmonary diseases and interstitial lung diseases, indicating the ability of perfusion SPECT superior to CT for detection of mild lesions in these disorders. The fusion images showed frequent ''steal phenomenon''-induced perfusion defects extending to the surrounding normal lung of arteriovenous fistulas and those at normal lungs on CT in hepatopulmonary syndrome. Comprehensive assessment of lung function-CT morphology on fusion images will lead to more profound understanding of lung pathophysiology in wide-spectral lung

Display of cross sectional anatomy by nuclear magnetic resonance imaging

International Nuclear Information System (INIS)

Hinshaw, W.S.; Andrew, E.R.; Bottomley, P.A.; Holland, G.N.; Moore, W.S.; Worthington, B.S.

1978-01-01

High definition cross-sectional images produced by a new nuclear magnetic resonace (NMR) technique are shown. The images are a series of thin section scans in the coronal plane of the head of a rabbit. The NMR images are derived from the distribution of the density of mobile hydrogen atoms. Various tissue types can be distinguished and a clear registration of gross anatomy is demonstrated. No known hazards are associated with the technique. (author)

Display of cross sectional anatomy by nuclear magnetic resonance imaging.

Science.gov (United States)

Hinshaw, W S; Andrew, E R; Bottomley, P A; Holland, G N; Moore, W S

1978-04-01

High definition cross-sectional images produced by a new nuclear magnetic resonance (NMR) technique are shown. The images are a series of thin section scans in the coronal plane of the head of a rabbit. The NMR images are derived from the distribution of the density of mobile hydrogen atoms. Various tissue types can be distinguished and a clear registration of gross anatomy is demonstrated. No known hazards are associated with the technique.

Health IT and inappropriate utilization of outpatient imaging: A cross-sectional study of U.S. hospitals.

Science.gov (United States)

Appari, Ajit; Johnson, M Eric; Anthony, Denise L

2018-01-01

To determine whether the use of information technology (IT), measured by Meaningful Use capability, is associated with lower rates of inappropriate utilization of imaging services in hospital outpatient settings. A retrospective cross-sectional analysis of 3332 nonfederal U.S. hospitals using data from: Hospital Compare (2011 outpatient imaging efficiency measures), HIMSS Analytics (2009 health IT), and Health Indicator Warehouse (market characteristics). Hospitals were categorized for their health IT infrastructure including EHR Stage-1 capability, and three advanced imaging functionalities/systems including integrated picture archiving and communication system, Web-based image distribution, and clinical decision support (CDS) with physician pathways. Three imaging efficiency measures suggesting inappropriate utilization during 2011 included: percentage of "combined" (with and without contrast) computed tomography (CT) studies out of all CT studies for abdomen and chest respectively, and percentage of magnetic resonance imaging (MRI) studies of lumbar spine without antecedent conservative therapy within 60days. For each measure, three separate regression models (GLM with gamma-log link function, and denominator of imaging measure as exposure) were estimated adjusting for hospital characteristics, market characteristics, and state fixed effects. Additionally, Heckman's Inverse Mills Ratio and propensity for Stage-1 EHR capability were used to account for selection bias. We find support for association of each of the four health IT capabilities with inappropriate utilization rates of one or more imaging modality. Stage-1 EHR capability is associated with lower inappropriate utilization rates for chest CT (incidence rate ratio IRR=0.72, p-value value value value value value value use of Stage-1 Meaningful Use capable EHR systems along with advanced imaging related functionalities could have a beneficial impact on reducing some of the inappropriate utilization of

Medical Therapies for Stricturing Crohn's Disease: Efficacy and Cross-Sectional Imaging Predictors of Therapeutic Failure.

Science.gov (United States)

Campos, Cécile; Perrey, Antoine; Lambert, Céline; Pereira, Bruno; Goutte, Marion; Dubois, Anne; Goutorbe, Felix; Dapoigny, Michel; Bommelaer, Gilles; Hordonneau, Constance; Buisson, Anthony

2017-06-01

Medical therapy efficacy remains controversial in stricturing Crohn's disease. Cross-sectional imaging, especially magnetic resonance imaging, has been suggested as very helpful to guide therapeutic decision making. To assess efficacy and predictors of therapeutic failure in patients receiving medical treatments for stricturing Crohn's disease. In this retrospective study, therapeutic failure was defined as symptomatic stricture leading to surgical or endoscopic therapeutics, hospitalization, treatment discontinuation or additional therapy and short-term clinical response as clinical improvement assessed by two physicians. The 55 cross-sectional imaging examinations (33 magnetic resonance imaging and 22 CT scan) before starting medical therapy were analyzed independently by two radiologists. Results were expressed as hazard ratio (HR) or odds ratio (OR) with 95% confidence intervals (95% CI). Among 84 patients, therapeutic failure rate within 60 months was 66.6%. In multivariate analysis, Crohn's disease diagnosis after 40 years old (HR 3.9, 95% CI [1.37-11.2], p = 0.011), small stricture luminal diameter (HR 1.34, 95% CI [1.01-1.80], p = 0.046), increased stricture wall thickness (HR 1.23, 95% CI [1.04-1.46], p = 0.013) and fistula with abscess (HR 5.63, 95% CI [1.64-19.35], p = 0.006) were associated with therapeutic failure, while anti-TNF combotherapy (HR 0.17, 95% CI [0.40-0.71], p = 0.015) prevented it. Considering 108 therapeutic sequences, the short-term clinical response rate was 65.7%. In multivariate analysis, male gender (OR 0.15, 95% CI [0.03-0.64], p = 0.011), fistula with abscess (OR 0.09, 95% CI [0.01-0.77], p = 0.028) and comb sign (OR 0.23, 95% CI [0.005-0.97], p = 0.047) were associated with short-term clinical failure. Anti-TNF combotherapy seemed to prevent therapeutic failure, and cross-sectional imaging should be systematically performed to help medical management in stricturing Crohn's disease.

Determination of tire cross-sectional geometric characteristics from a digitally scanned image

Science.gov (United States)

Danielson, Kent T.

1995-08-01

A semi-automated procedure is described for the accurate determination of geometrical characteristics using a scanned image of the tire cross-section. The procedure can be useful for cases when CAD drawings are not available or when a description of the actual cured tire is desired. Curves representing the perimeter of the tire cross-section are determined by an edge tracing scheme, and the plyline and cord-end positions are determined by locations of color intensities. The procedure provides an accurate description of the perimeter of the tire cross-section and the locations of plylines and cord-ends. The position, normals, and curvatures of the cross-sectional surface are included in this description. The locations of the plylines provide the necessary information for determining the ply thicknesses and relative position to a reference surface. Finally, the locations of the cord-ends provide a means to calculate the cord-ends per inch (epi). Menu driven software has been developed to facilitate the procedure using the commercial code, PV-Wave by Visual Numerics, Inc., to display the images. From a single user interface, separate modules are executed for image enhancement, curve fitting the edge trace of the cross-sectional perimeter, and determining the plyline and cord-end locations. The code can run on SUN or SGI workstations and requires the use of a mouse to specify options or identify items on the scanned image.

Evaluation of aortocoronary bypass graft patency by reconstructed CT image

International Nuclear Information System (INIS)

Kawakita, Seizaburo; Koide, Takashi; Saito, Yoshio; Yamamoto, Tadao; Iwasaki, Tadaaki

1982-01-01

Ten patients were examined in the period of three months from January to March 1981. The patients were operated from 1 month to 7 years before CT. A bypass to the left anterior descending artery (LAD) was grafted in 10 cases, 2 to the right coronary artery (RCA), 4 to an obtuse marginal artery (OM), and 1 to a diagonal artery. Image reconstruction was performed in 10 cases by using an image analytical computer Evaluskop. Appropriate planes for reconstruction were selected by trial and error methods upon observation of CT images. When gained picture of a graft course coincided with surgical records or angiography, the work of building images was concluded. On cross section, grafts to LAD were visualized in all 10 cases: 9 in the entire course and 1 in a proximal part of the graft. Two to RCA, 4 to OM and 1 to a diagonal were also successfully visualized. Reconstruction of graft images succeeded in 9 grafts of 6 cases. The course of a graft could be pursued from the proximal to the distal end adjacent to the cardiac chamber. The picture of a bypass to LAD was visualized in 6 of 10 grafts. Two bypass to RCA could be depicted, and 1 to OM was also found. However 3 to OM and 1 to a diagonal failed to be visualized throughout their courses in reconstructed images. I think that the causes of faillure mainly depended upon the course of the graft. When a graft was running arc-like surrounding the heart chamber, it was very difficult to depict its entire length in reconstructed images, though the graft could be detected in cross sections. These preliminary studies indicated that reconstruction of CT images had some benefits for the pursuit of graft courses. (J.P.N.)

Deep learning of the sectional appearances of 3D CT images for anatomical structure segmentation based on an FCN voting method.

Science.gov (United States)

Zhou, Xiangrong; Takayama, Ryosuke; Wang, Song; Hara, Takeshi; Fujita, Hiroshi

2017-10-01

issue of anatomical structure segmentation in 3D CT cases. The novelty of this work is the policy of deep learning of the different 2D sectional appearances of 3D anatomical structures for CT cases and the majority voting of the 3D segmentation results from multiple crossed 2D sections to achieve availability and reliability with better efficiency, generality, and flexibility than conventional segmentation methods, which must be guided by human expertise. © 2017 The Authors. Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

Children's (Pediatric) CT (Computed Tomography)

Medline Plus

Full Text Available ... images or pictures of the inside of the body. The cross-sectional images generated during a CT ... be performed to evaluate blood vessels throughout the body. With CT, it is possible to obtain very ...

Spinal trauma: first aid from cross-sectional imaging; Trauma der Wirbelsaeule: erste Hilfe durch Schnittbildverfahren

Energy Technology Data Exchange (ETDEWEB)

Schueller, G.; Schueller-Weidekamm, C. [Emergency Radiology Schueller, Neerach (Switzerland)

2014-09-15

The diagnosis of the traumatized spine is one of the key issues for trauma radiologists. The cross-sectional imaging procedures, computed tomography (CT) and magnetic resonance imaging (MRI) are the essential methods in spinal trauma radiology. These modalities are of great help in accurately assessing injury patterns and extent and in providing indications of patient outcome. In contrast to cross-sectional imaging, radiography has a role in the evaluation of minor spinal trauma only. It is generally accepted that trauma radiologists do not use typical classifications to evaluate the spine partly because such an ideal classification system does not yet exist. Not least because of this classification difficulty, eponyms and synonyms are widely used to describe traumatology of the spine as a high level of specific information is included in these various terms. The members of the trauma team should be aware of the strengths and limitations of the methods used in the assessment of the spine. This article provides a brief outline of fundamental knowledge about the diagnosis of spinal trauma. (orig.) [German] Die Beurteilung der verletzten Wirbelsaeule nimmt fuer Traumaradiologen eine zentrale Stellung ein. Die Schnittbildverfahren CT und MRT sind ihre wesentlichen Arbeitsmethoden. Sie helfen dabei, schnell und mit hoher Zuverlaessigkeit Aussagen ueber Art und Ausmass von Verletzungen zu treffen sowie Hinweise auf die Prognose der Patienten zu geben. Die Projektionsradiographie hat ihre Bedeutung lediglich in der Diagnostik des Bagatelltraumas und ist in ihrer Aussagekraft auch dort nicht unumstritten. Traumaradiologen bedienen sich nicht ausschliesslich typischer Klassifikationen des Wirbelsaeulentraumas, z. T. auch deshalb, da es die ideale Klassifikation aus heutiger Sicht nicht gibt. Vielmehr ist es wichtig, auch ueber Eponyme und Synonyme Bescheid zu wissen, da sie ein hohes Mass an spezifischen Informationen der spinalen Verletzungen verinnerlichen. Alle

Scalar properties of transversely isotropic tuff from images of orthogonal cross sections

International Nuclear Information System (INIS)

Berge, P.A.; Berryman, J.G.; Blair, S.C.; Pena, C.

1997-01-01

Image processing methods have been used very effectively to estimate physical properties of isotropic porous earth materials such as sandstones. Anisotropic materials can also be analyzed in order to estimate their physical properties, but additional care and a larger number of well-chosen images of cross sections are required to obtain correct results. Although low-symmetry anisotropic media present difficulties for two-dimensional image processing methods, geologic materials are often transversely isotropic. Scalar properties of porous materials such as porosity and specific surface area can be determined with only minor changes in the analysis when the medium is transversely isotropic rather than isotropic. For example, in a rock that is transitively isotropic due to thin layers or beds, the overall porosity may be obtained by analyzing images of cross sections taken orthogonal to the bedding planes, whereas cross sections lying within the bedding planes will determine only the local porosity of the bed itself. It is known for translationally invariant anisotropic media that the overall specific surface area can be obtained from radial averages of the two-point correlation function in the full three-dimensional volume. Layered materials are not translationally invariant in the direction of the layering, but we show nevertheless how averages of cross sections may be used to obtain the specific surface area for a transversely isotropic rock. We report values of specific surface area obtained for thin sections of Topopah Spring Tuff from Yucca Mountain, Nevada. This formation is being evaluated as a potential host rock for geologic disposal of nuclear waste. Although the present work has made use of thin sections of tuff for the images, the same methods of analysis could also be used to simplify quantitative analysis of three-dimensional volumes of pore structure data obtained by means of x-ray microtomography or other methods, using only a few representative cross

Display of cross sectional anatomy by nuclear magnetic resonance imaging. 1978.

Science.gov (United States)

Hinshaw, W S; Andrew, E R; Bottomley, P A; Holland, G N; Moore, W S

1995-12-01

High definition cross-sectional images produced by a new nuclear magnetic resonance (NMR) technique are shown. The images are a series of thin section scans in the coronal plane of the head of a rabbit. The NMR images are derived from the distribution of the density of mobile hydrogen atoms. Various tissue types can be distinguished and a clear registration of gross anatomy is demonstrated. No known hazards are associated with the technique.

CT images of gossypiboma

International Nuclear Information System (INIS)

Jeon, Hae Jeong; Lim, Jong Nam; Choi, Young Chil; Park, Jeong Hee

1994-01-01

Surgical sponges retained after laparotomy can cause serious problem if they were not be identified in early state. In these circumstances abdominal CT yields the accurate diagnostic images. The purpose of this report is to present highly indicative findings permitting correct preoperative diagnosis of the gossypiboma. We experienced three cases in which CT showed the images sufficiently characteristic to suggest the correct preoperative diagnosis. We evaluated retrospectively the radiological images of gossypiboma confirmed by operation. Three patients were admitted due to palpable masses. Two female patients had medical histories of cesarean sections and a male patient had been operated due to malignant fibrous histiocytoma, previously. Abdominal CT scan of one case revealed huge ovoid hypodense mass with enhanced peripheral rim. Calcific spots and whirl-like stripes were noted within the lesion. Towel was found in pathologic specimen. CT images of two patients showed well-encapsulated, mixed fluid and soft tissue density mass with several gas bubbles. Surgical sponges were found within abscesses. The authors conclude that these characteristic CT findings and careful histories of surgery are very useful for correct pre-operative diagnosis and permit the guideline for the optimal plan of the surgical treatment

CT images of gossypiboma

Energy Technology Data Exchange (ETDEWEB)

Jeon, Hae Jeong; Lim, Jong Nam; Choi, Young Chil; Park, Jeong Hee [College of Medicine, Kon-Kuk University, Seoul (Korea, Republic of)

1994-04-15

Surgical sponges retained after laparotomy can cause serious problem if they were not be identified in early state. In these circumstances abdominal CT yields the accurate diagnostic images. The purpose of this report is to present highly indicative findings permitting correct preoperative diagnosis of the gossypiboma. We experienced three cases in which CT showed the images sufficiently characteristic to suggest the correct preoperative diagnosis. We evaluated retrospectively the radiological images of gossypiboma confirmed by operation. Three patients were admitted due to palpable masses. Two female patients had medical histories of cesarean sections and a male patient had been operated due to malignant fibrous histiocytoma, previously. Abdominal CT scan of one case revealed huge ovoid hypodense mass with enhanced peripheral rim. Calcific spots and whirl-like stripes were noted within the lesion. Towel was found in pathologic specimen. CT images of two patients showed well-encapsulated, mixed fluid and soft tissue density mass with several gas bubbles. Surgical sponges were found within abscesses. The authors conclude that these characteristic CT findings and careful histories of surgery are very useful for correct pre-operative diagnosis and permit the guideline for the optimal plan of the surgical treatment.

Dynamic multidetector CT and non-contrast-enhanced MR for right adrenal vein imaging: comparison with catheter venography in adrenal venous sampling

Energy Technology Data Exchange (ETDEWEB)

Ota, Hideki; Seiji, Kazumasa; Kawabata, Masahiro; Satani, Nozomi; Matsuura, Tomonori; Tominaga, Junya; Takase, Kei [Tohoku University Hospital, Department of Diagnostic Radiology, Sendai (Japan); Omata, Kei; Ono, Yoshikiyo; Iwakura, Yoshitsugu; Morimoto, Ryo; Kudo, Masataka; Satoh, Fumitoshi; Ito, Sadayoshi [Tohoku University Hospital, Division of Nephrology, Endocrinology and Vascular Medicine, Sendai (Japan)

2016-03-15

To evaluate visualization of the right adrenal vein (RAV) with multidetector CT and non-contrast-enhanced MR imaging in patients with primary aldosteronism. A total of 125 patients (67 men) scheduled for adrenal venous sampling (AVS) were included. Dynamic 64-detector-row CT and balanced steady-state free precession-based non-contrast-enhanced 3-T MR imaging were performed. RAV visualization based on a four-point score was documented. Both anatomical location and variation on cross-sectional imaging were evaluated, and the findings were compared with catheter venography as the gold standard. The RAV was visualized in 93.2 % by CT and 84.8 % by MR imaging (p = 0.02). Positive predictive values of RAV visualization were 100 % for CT and 95.2 % for MR imaging. Imaging score was significantly higher in CT than MR imaging (p < 0.01). The RAV formed a common trunk with an accessory hepatic vein in 16 % of patients. The RAV orifice level on cross-sectional imaging was concordant with catheter venography within the range of 1/3 vertebral height in >70 % of subjects. Success rate of AVS was 99.2 %. Dynamic CT is a reliable way to map the RAV prior to AVS. Non-contrast-enhanced MR imaging is an alternative when there is a risk of complication from contrast media or radiation exposure. (orig.)

Laser radar cross-section estimation from high-resolution image data.

Science.gov (United States)

Osche, G R; Seeber, K N; Lok, Y F; Young, D S

1992-05-10

A methodology for the estimation of ladar cross sections from high-resolution image data of geometrically complex targets is presented. Coherent CO(2) laser radar was used to generate high-resolution amplitude imagery of a UC-8 Buffalo test aircraft at a range of 1.3 km at nine different aspect angles. The average target ladar cross section was synthesized from these data and calculated to be sigma(T) = 15.4 dBsm, which is similar to the expected microwave radar cross sections. The aspect angle dependence of the cross section shows pronounced peaks at nose on and broadside, which are also in agreement with radar results. Strong variations in both the mean amplitude and the statistical distributions of amplitude with the aspect angle have also been observed. The relative mix of diffuse and specular returns causes significant deviations from a simple Lambertian or Swerling II target, especially at broadside where large normal surfaces are present.

Material Science Image Analysis using Quant-CT in ImageJ

Energy Technology Data Exchange (ETDEWEB)

Ushizima, Daniela M.; Bianchi, Andrea G. C.; DeBianchi, Christina; Bethel, E. Wes

2015-01-05

We introduce a computational analysis workflow to access properties of solid objects using nondestructive imaging techniques that rely on X-ray imaging. The goal is to process and quantify structures from material science sample cross sections. The algorithms can differentiate the porous media (high density material) from the void (background, low density media) using a Boolean classifier, so that we can extract features, such as volume, surface area, granularity spectrum, porosity, among others. Our workflow, Quant-CT, leverages several algorithms from ImageJ, such as statistical region merging and 3D object counter. It also includes schemes for bilateral filtering that use a 3D kernel, for parallel processing of sub-stacks, and for handling over-segmentation using histogram similarities. The Quant-CT supports fast user interaction, providing the ability for the user to train the algorithm via subsamples to feed its core algorithms with automated parameterization. Quant-CT plugin is currently available for testing by personnel at the Advanced Light Source and Earth Sciences Divisions and Energy Frontier Research Center (EFRC), LBNL, as part of their research on porous materials. The goal is to understand the processes in fluid-rock systems for the geologic sequestration of CO2, and to develop technology for the safe storage of CO2 in deep subsurface rock formations. We describe our implementation, and demonstrate our plugin on porous material images. This paper targets end-users, with relevant information for developers to extend its current capabilities.

Computed tomography and cross-sectional anatomy of the metatarsus and digits of the one-humped camel (Camelus dromedarius) and buffalo ( Bos bubalis).

Science.gov (United States)

El-Shafey, A; Kassab, A

2013-04-01

The purpose of the present study was to provide a detailed computed tomography (CT) and cross-sectional anatomic reference of the normal metatarsus and digits for the camel and buffalo, as well as to compare between metatarsus and digits in these animals to outstand a basis for diagnosis of their diseases. Advantages, including depiction of detailed cross-sectional anatomy, improved contrast resolution and computer reformatting, make it a potentially valuable diagnostic technique. The hind limbs of 12 healthy adult camel and buffalo were used. Clinically relevant anatomic structures were identified and labelled at each level in the corresponding images (CT and anatomic slices). CT images were used to identify the bony and soft tissue structures of the metatarsus and digits. The knowledge of normal anatomy of the camel and buffalo metatarsus and digits would serve as initial reference to the evaluation of CT images in these species. © 2012 Blackwell Verlag GmbH.

[Landmark-based automatic registration of serial cross-sectional images of Chinese digital human using Photoshop and Matlab software].

Science.gov (United States)

Su, Xiu-yun; Pei, Guo-xian; Yu, Bin; Hu, Yan-ling; Li, Jin; Huang, Qian; Li, Xu; Zhang, Yuan-zhi

2007-12-01

This paper describes automatic registration of the serial cross-sectional images of Chinese digital human by projective registration method based on the landmarks using the commercially available software Photoshop and Matlab. During cadaver embedment for acquisition of the Chinese digital human images, 4 rods were placed parallel to the vertical axis of the frozen cadaver to allow orientation. Projective distortion of the rod positions on the cross-sectional images was inevitable due to even slight changes of the relative position of the camera. The original cross-sectional images were first processed using Photoshop software firstly to obtain the images of the orientation rods, and the centroid coordinate of every rod image was acquired with Matlab software. With the average coordinate value of the rods as the fiducial point, two-dimensional projective transformation coefficient of each image was determined. Projective transformation was then carried out and projective distortion from each original serial image was eliminated. The rectified cross-sectional images were again processed using Photoshop to obtain the image of the first orientation rod, the coordinate value of first rod image was calculated using Matlab software, and the cross-sectional images were cut into images of the same size according to the first rod spatial coordinate, to achieve automatic registration of the serial cross-sectional images. sing Photoshop and Matlab softwares, projective transformation can accurately accomplish the image registration for the serial images with simpler calculation processes and easier computer processing.

Changes in measured size of atherosclerotic plaque calcifications in dual-energy CT of ex vivo carotid endarterectomy specimens: effect of monochromatic keV image reconstructions

International Nuclear Information System (INIS)

Mannelli, Lorenzo; Mitsumori, Lee M.; Ferguson, Marina; Xu, Dongxiang; Chu, Baocheng; Branch, Kelley R.; Shuman, William P.; Yuan, Chun

2013-01-01

The aim of this study was to compare the size of the calcifications measured on the different keV images to a histological standard. Five ex vivo carotid endarterectomy (CEA) specimens were imaged with a dual-energy CT. CT images were reconstructed at different monochromatic spectral energies (40, 60, 77, 80, 100, 120, 140 keV). Cross-sectional area of the plaque calcifications present on each CT image was measured. The histological calcium areas on each corresponding CEA specimen were traced manually on digitised images of Toluidine Blue/Basic Fuchsin stained plastic sections. The CT images and corresponding histology sections were matched. The CT-derived calcium areas on each keV image were compared to the calcified area measurements by histology. A total of 107 histology sections were matched to corresponding CT images. The average calcified area per section by histology was 7.6 ± 7 mm 2 (range 0-26.4 mm 2 ). There was no significant difference between the calcified areas measured by histology and those measured on CT-virtual monochromatic spectral (VMS) reconstructed images at 77 keV (P = 0.08), 80 keV (P = 0.20) and 100 keV (P = 0.14). Calcium area measured on the 80 keV image set was most comparable to the amount of calcium measured by histology. (orig.)

Image Registration for PET/CT and CT Images with Particle Swarm Optimization

International Nuclear Information System (INIS)

Lee, Hak Jae; Kim, Yong Kwon; Lee, Ki Sung; Choi, Jong Hak; Kim, Chang Kyun; Moon, Guk Hyun; Joo, Sung Kwan; Kim, Kyeong Min; Cheon, Gi Jeong

2009-01-01

Image registration is a fundamental task in image processing used to match two or more images. It gives new information to the radiologists by matching images from different modalities. The objective of this study is to develop 2D image registration algorithm for PET/CT and CT images acquired by different systems at different times. We matched two CT images first (one from standalone CT and the other from PET/CT) that contain affluent anatomical information. Then, we geometrically transformed PET image according to the results of transformation parameters calculated by the previous step. We have used Affine transform to match the target and reference images. For the similarity measure, mutual information was explored. Use of particle swarm algorithm optimized the performance by finding the best matched parameter set within a reasonable amount of time. The results show good agreements of the images between PET/CT and CT. We expect the proposed algorithm can be used not only for PET/CT and CT image registration but also for different multi-modality imaging systems such as SPECT/CT, MRI/PET and so on.

Cross Sectional Imaging of Solitary Lesions of the Neurocranium.

Science.gov (United States)

Schäfer, Max-Ludwig; Koch, Arend; Streitparth, Florian; Wiener, Edzard

2017-12-01

Background  Although a wide range of processes along the neurocranium are of a benign nature, there are often difficulties in the differential diagnosis. Method  In the review CT/MRI scans of the head were evaluated retrospectively regarding solitary lesions along the neurocranium. The majority of the lesions were histologically proven. Results  The purpose of the review is to present typical pathologies of the neurocranium and provide a systematic overview based on 12 entities, their locations, prevalence and radiological characteristics. Conclusion  Processes, which primarily originate from the neurocranium have to be differentiated from secondary processes infiltrating the neurocranium. For this important diagnostic feature, MRI is typically essential, while the definitive diagnosis is often made on the basis of the medical history and the typical appearance on computer tomography. Key Points   · There are often difficulties in the precise differential diagnosis of solitary lesions along the neurocranium. Typical solitary pathologies of the neurocranium based on 12 entities were presented. Both magnetic resonance imaging and computed tomography are often essential for an exact differential diagnosis.. Citation Format · Schäfer M, Koch A, Streitparth F et al. Cross Sectional Diagnosis of Solitary Lesions of the Neurocranium. Fortschr Röntgenstr 2017; 189: 1135 - 1144. © Georg Thieme Verlag KG Stuttgart · New York.

Imaging of jaw with dental CT software program: Normal Anatomy

International Nuclear Information System (INIS)

Kim, Myong Gon; Seo, Kwang Hee; Jung, Hak Young; Sung, Nak Kwan; Chung, Duk Soo; Kim, Ok Dong; Lee, Young Hwan

1994-01-01

Dental CT software program can provide reformatted cross-sectional and panoramic images that cannot be obtained with conventional axial and direct coronal CT scan. The purpose of this study is to describe the method of the technique and to identify the precise anatomy of jaw. We evaluated 13 mandibles and 7 maxillae of 15 subjects without bony disease who were being considered for endosseous dental implants. Reformatted images obtained by the use of bone algorithm performed on GE HiSpeed Advantage CT scanner were retrospectively reviewed for detailed anatomy of jaw. Anatomy related to neurovascular bundle(mandibular foramen, inferior alveolar canal, mental foramen, canal for incisive artery, nutrient canal, lingual foramen and mylohyoid groove), muscular insertion(mylohyoid line, superior and inferior genial tubercle and digastric fossa) and other anatomy(submandibular fossa, sublingual fossa, contour of alveolar process, oblique line, retromolar fossa, temporal crest and retromolar triangle) were well delineated in mandible. In maxilla, anatomy related to neurovascular bundle(greater palatine foramen and groove, nasopalatine canal and incisive foramen) and other anatomy(alveolar process, maxillary sinus and nasal fossa) were also well delineated. Reformatted images using dental CT software program provided excellent delineation of the jaw anatomy. Therefore, dental CT software program can play an important role in the preoperative assessment of mandible and maxilla for dental implants and other surgical conditions

Assessing apical transportation in curved canals: comparison between cross-sections and micro-computed tomography

Directory of Open Access Journals (Sweden)

Laila Gonzales Freire

2012-06-01

Full Text Available The aim of this study was to compare two methods of assessing apical transportation in curved canals after rotary instrumentation, namely, cross-sections and micro-computed tomography (µCT. Thirty mandibular molars were divided into two groups and prepared according to the requirements of each method. In G1 (cross-sections, teeth were embedded in resin blocks and sectioned at 2.0, 3.5, and 5.0 mm from the anatomic apex. Pre- and postoperative sections were photographed and analyzed. In G2 (µCT, teeth were embedded in a rubber-base impression material and scanned before and after instrumentation. Mesiobuccal canals were instrumented with the Twisted File (TF system (SybronEndo, Orange, USA, and mesiolingual canals, with the EndoSequence (ES system (Brasseler, Savannah, USA. Images were reconstructed, and sections corresponding to distances 2.0, 3.5, and 5.0 mm from the anatomic apex were selected for comparison. Data were analyzed using Mann-Whitney's test at a 5% significance level. The TF and ES instruments produced little deviation from the root canal center, with no statistical difference between them (P > 0.05. The canal transportation results were significantly lower (0.056 mm in G2 than in G1 (0.089 mm (p = 0.0012. The µCT method was superior to the cross-section method, especially in view of its ability to preserve specimens and provide results that are more closely related to clinical situations.

Imaging of head and neck tumors -- methods: CT, spiral-CT, multislice-spiral-CT

International Nuclear Information System (INIS)

Baum, Ulrich; Greess, Holger; Lell, Michael; Noemayr, Anton; Lenz, Martin

2000-01-01

Spiral-CT is standard for imaging neck tumors. In correspondence with other groups we routinely use spiral-CT with thin slices (3 mm), a pitch of 1.3-1.5 and an overlapping reconstruction increment (2-3 mm). In patients with dental fillings a short additional spiral parallel to the corpus of the mandible reduces artifacts behind the dental arches and improves the diagnostic value of CT. For the assessment of the base of the skull, the orbital floor, the palate and paranasal sinuses an additional examination in the coronal plane is helpful. Secondary coronal reconstructions of axial scans are helpful in the evaluation of the crossing of the midline by small tumors of the tongue base or palate. For an optimal vascular or tissue contrast a sufficient volume of contrast medium and a start delay greater than 70-80 s are necessary. In our opinion the best results can be achieved with a volume of 150 ml, a flow of 2.5 ml/s and a start delay of 80 s. Dynamic enhanced CT is only necessary in some special cases. There is clear indication for dynamic enhanced CT where a glomus tumor is suspected. Additional functional CT imaging during i-phonation and/or Valsalva's maneuver are of great importance to prove vocal cords mobility. Therefore, imaging during i-phonation is an elemental part of every thorough examination of the hypopharynx and larynx region. Multislice-spiral-CT allows almost isotropic imaging of the head and neck region and improves the assessment of tumor spread and lymph node metastases in arbitrary oblique planes. Thin structures (the base of the skull, the orbital floor, the hard palate) as well as the floor of the mouth can be evaluated sufficiently with multiplanar reformations. Usually, additional coronal scanning is not necessary with multislice-spiral-CT. Multislice-spiral-CT is especially advantageous in defining the critical relationships of tumor and lymph node metastases and for functional imaging of the hypopharynx and larynx not only in the

The construction of trunk voxel phantom by using CT images and application to 3 dimensional radiotherapy treatment planning

Energy Technology Data Exchange (ETDEWEB)

Lee, C. S.; Lee, J. K. [Hanyang Univ., Seoul (Korea, Republic of)

2001-10-01

Trunk voxel phantom was constructed by using whole body CT images and tumor doses were calculated by using Monte Carlo method after simulating situation of radiotheraphy treatment planning. The whole body CT images of VHP (Visual Human Project) man were acquired from National Library of Medicine of USA. 153 slices of trunk part were extracted from whole body CT images and MCNP4B, a general purpose Monte Carlo code, was used for dose calculation. Gray scale of CT images were converted into density of medium and processed into trunk voxel phantom ported to MCNP4B input deck. The conversion method was verified by comparing cross sectional images of voxel phantom with original CT images. Tumor volumes with diameter of 3 cm were defined in liver, stomach and right lung and irradiated with 5, 10 and 15 MeV gamma beam with diameter of 6 cm. The technical basis for 3D dose calculation was established through this study for localization of 3D RTP system.

The first joint ESGAR/ ESPR consensus statement on the technical performance of cross-sectional small bowel and colonic imaging

International Nuclear Information System (INIS)

Taylor, S.A.; Torkzad, M.R.; Bhatnagar, G.; Avni, F.; Cronin, C.G.; Hoeffel, C.; Kim, S.H.; Laghi, A.; Napolitano, M.; Petit, P.; Rimola, J.; Tolan, D.J.; Zappa, M.; Puylaert, C.A.J.; Stoker, J.

2017-01-01

To develop guidelines describing a standardised approach to patient preparation and acquisition protocols for magnetic resonance imaging (MRI), computed tomography (CT) and ultrasound (US) of the small bowel and colon, with an emphasis on imaging inflammatory bowel disease. An expert consensus committee of 13 members from the European Society of Gastrointestinal and Abdominal Radiology (ESGAR) and European Society of Paediatric Radiology (ESPR) undertook a six-stage modified Delphi process, including a detailed literature review, to create a series of consensus statements concerning patient preparation, imaging hardware and image acquisition protocols. One hundred and fifty-seven statements were scored for agreement by the panel of which 129 statements (82 %) achieved immediate consensus with a further 19 (12 %) achieving consensus after appropriate modification. Nine (6 %) statements were rejected as consensus could not be reached. These expert consensus recommendations can be used to help guide cross-sectional radiological practice for imaging the small bowel and colon. (orig.)

The first joint ESGAR/ ESPR consensus statement on the technical performance of cross-sectional small bowel and colonic imaging

Energy Technology Data Exchange (ETDEWEB)

Taylor, S.A.; Torkzad, M.R.; Bhatnagar, G. [University College London, Centre for Medical Imaging, London (United Kingdom); Avni, F. [Lille University Hospitals, Department of Paediatric Imaging, Jeanne de Flandre Hospital, Lille (France); Cronin, C.G. [Mater Misericordiae University Hospital, Department of Radiology, Dublin (Ireland); Hoeffel, C. [Hopital Robert Debre, Department of Radiology, Reims (France); Kim, S.H. [Inje University College of Medicine, Haeundae Paik Hospital, Department of Radiology, Busan (Korea, Republic of); Laghi, A. [Sapienza University of Rome, I.C.O.T. Hospital, Department of Radiological Sciences, Oncology and Pathology, Latina (Italy); Napolitano, M. [V. Buzzi Children' s Hospital, Department of Radiology and Neuroradiology, Milan (Italy); Petit, P. [Timone Enfant Hospital, Department of Paediatric Radiology, Marseille (France); Rimola, J. [University of Barcelona, Radiology Department, Hospital Clinic Barcelona, Catalonia (Spain); Tolan, D.J. [St James' s University Hospital, Leeds Teaching Hospitals NHS Trust (United Kingdom); Zappa, M. [Hopital Beaujon, AP-HP, Universite Paris 7, INSERM CRI U1149, Department of Radiology, Clichy (France); Puylaert, C.A.J.; Stoker, J. [University of Amsterdam, Department of Radiology, Academic Medical Centre, Amsterdam (Netherlands)

2017-06-15

To develop guidelines describing a standardised approach to patient preparation and acquisition protocols for magnetic resonance imaging (MRI), computed tomography (CT) and ultrasound (US) of the small bowel and colon, with an emphasis on imaging inflammatory bowel disease. An expert consensus committee of 13 members from the European Society of Gastrointestinal and Abdominal Radiology (ESGAR) and European Society of Paediatric Radiology (ESPR) undertook a six-stage modified Delphi process, including a detailed literature review, to create a series of consensus statements concerning patient preparation, imaging hardware and image acquisition protocols. One hundred and fifty-seven statements were scored for agreement by the panel of which 129 statements (82 %) achieved immediate consensus with a further 19 (12 %) achieving consensus after appropriate modification. Nine (6 %) statements were rejected as consensus could not be reached. These expert consensus recommendations can be used to help guide cross-sectional radiological practice for imaging the small bowel and colon. (orig.)

Brain neuroimaging of domestic cats: correlation between computed tomography and cross-sectional anatomy

International Nuclear Information System (INIS)

Nepomuceno, A.C.; Zanatta, R.; Chung, D.G.; Costa, P.F.; Feliciano, M.A.R.; Avante, M.L.; Canola, J.C.; Lopes, L.S.

2016-01-01

Computed tomography of the brain is necessary as part of the diagnosis of lesions of the central nervous system. In this study we used six domestic cats, male or female, aged between one and five years, evaluated by Computed Tomography (CT) examination without clinical signs of central nervous system disorders. Two euthanized animals stating a condition unrelated to the nervous system were incorporated into this study. The proposal consisted in establishing detailed anatomical description of tomographic images of normal brain of cats, using as reference anatomical images of cross sections of the stained brain and cranial part, with thicknesses similar to the planes of the CT images. CT examinations were performed with and without intravenous iodinated contrast media for live animals. With one euthanized animal, the brain was removed and immediately preserved in 10% formalin for later achievement in cross-sectional thickness of approximately 4mm and staining technique of Barnard, and Robert Brown. The head of another animal was disarticulated in the Atlanto-occipital region and frozen at -20 deg C then sliced to a thickness of about 5mm. The description of visualized anatomical structures using tomography is useful as a guide and allows transcribing with relative accuracy the brain region affected by an injury, and thus correlating it with the clinical symptoms of the patient, providing additional information and consequent improvement to veterinarians during the course of surgical clinic in this species. (author)

Brain neuroimaging of domestic cats: correlation between computed tomography and cross-sectional anatomy

Energy Technology Data Exchange (ETDEWEB)

Nepomuceno, A.C. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil); Zanatta, R. [Universidade de Cuiaba, MT (Brazil); Chung, D.G.; Costa, P.F.; Feliciano, M.A.R.; Avante, M.L.; Canola, J.C., E-mail: marcusfeliciano@yahoo.com.br [Faculdade de Ciencias Agrarias e Veterinarias, Jaboticabal, SP (Brazil); Lopes, L.S. [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil)

2016-09-15

Computed tomography of the brain is necessary as part of the diagnosis of lesions of the central nervous system. In this study we used six domestic cats, male or female, aged between one and five years, evaluated by Computed Tomography (CT) examination without clinical signs of central nervous system disorders. Two euthanized animals stating a condition unrelated to the nervous system were incorporated into this study. The proposal consisted in establishing detailed anatomical description of tomographic images of normal brain of cats, using as reference anatomical images of cross sections of the stained brain and cranial part, with thicknesses similar to the planes of the CT images. CT examinations were performed with and without intravenous iodinated contrast media for live animals. With one euthanized animal, the brain was removed and immediately preserved in 10% formalin for later achievement in cross-sectional thickness of approximately 4mm and staining technique of Barnard, and Robert Brown. The head of another animal was disarticulated in the Atlanto-occipital region and frozen at -20 deg C then sliced to a thickness of about 5mm. The description of visualized anatomical structures using tomography is useful as a guide and allows transcribing with relative accuracy the brain region affected by an injury, and thus correlating it with the clinical symptoms of the patient, providing additional information and consequent improvement to veterinarians during the course of surgical clinic in this species. (author)

Ultrasound and PET-CT image fusion for prostate brachytherapy image guidance

International Nuclear Information System (INIS)

Hasford, F.

2015-01-01

Fusion of medical images between different cross-sectional modalities is widely used, mostly where functional images are fused with anatomical data. Ultrasound has for some time now been the standard imaging technique used for treatment planning of prostate cancer cases. While this approach is laudable and has yielded some positive results, latest developments have been the integration of images from ultrasound and other modalities such as PET-CT to compliment missing properties of ultrasound images. This study has sought to enhance diagnosis and treatment of prostate cancers by developing MATLAB algorithms to fuse ultrasound and PET-CT images. The fused ultrasound-PET-CT image has shown to contain improved quality of information than the individual input images. The fused image has the property of reduced uncertainty, increased reliability, robust system performance, and compact representation of information. The objective of co-registering the ultrasound and PET-CT images was achieved by conducting performance evaluation of the ultrasound and PET-CT imaging systems, developing image contrast enhancement algorithm, developing MATLAB image fusion algorithm, and assessing accuracy of the fusion algorithm. Performance evaluation of the ultrasound brachytherapy system produced satisfactory results in accordance with set tolerances as recommended by AAPM TG 128. Using an ultrasound brachytherapy quality assurance phantom, average axial distance measurement of 10.11 ± 0.11 mm was estimated. Average lateral distance measurements of 10.08 ± 0.07 mm, 20.01 ± 0.06 mm, 29.89 ± 0.03 mm and 39.84 ± 0.37 mm were estimated for the inter-target distances corresponding to 10 mm, 20 mm, 30 mm and 40 mm respectively. Volume accuracy assessment produced measurements of 3.97 cm 3 , 8.86 cm 3 and 20.11 cm 3 for known standard volumes of 4 cm 3 , 9 cm 3 and 20 cm 3 respectively. Depth of penetration assessment of the ultrasound system produced an estimate of 5.37 ± 0.02 cm

Cross-sectional Imaging Review of Tuberous Sclerosis.

Science.gov (United States)

Krishnan, Anant; Kaza, Ravi K; Vummidi, Dharshan R

2016-05-01

Tuberous sclerosis complex (TSC) is a multisystem, genetic disorder characterized by development of hamartomas in the brain, abdomen, and thorax. It results from a mutation in one of 2 tumor suppressor genes that activates the mammalian target of rapamycin pathway. This article discusses the origins of the disorder, the recently updated criteria for the diagnosis of TSC, and the cross-sectional imaging findings and recommendations for surveillance. Familiarity with the diverse radiological features facilitates diagnosis and helps in treatment planning and monitoring response to treatment of this multisystem disorder. Copyright © 2016 Elsevier Inc. All rights reserved.

Short linear shadows connecting pulmonary segmental arteries to oblique fissures in volumetric thin-section CT images: comparing CT, micro-CT and histopathology

International Nuclear Information System (INIS)

Guan, Chun-Shuang; Ma, Da-Qing; Chen, Jiang-Hong; Chen, Bu-Dong; Cui, Dun; Zhang, Yan-Song; Liu, Wei-Hua

2016-01-01

To retrospectively evaluate short linear shadows connecting pulmonary segmental arteries to oblique fissures in thin-section CT images and determine their anatomical basis. CT scanning was performed on 108 patients and 11 lung specimens with no lung diseases around the oblique fissures or hilar. Two radiologists evaluated the imaging. The parameters included length, thickness of short linear shadows, pulmonary segmental artery variations, and traction interlobar fissures, etc. The short linear shadows were not related to sex, age, or smoking history. The lengths of the short linear shadows were generally within 10 mm. The thicknesses of the short linear shadows ranged from 1 to 2 mm. Of the patients, 26.9 % showed pulmonary segmental artery variations; 66.7 % of short linear shadows pulled oblique fissures. In three-dimensional images, the short linear shadows appeared as arc planes, with one side edge connected to the oblique fissure, one side edge connected to a pulmonary segmental artery. On the tissue slices, the short linear shadow exhibited a band structure composed of connective tissues, small blood vessels, and small lymphatic vessels. Short linear shadows are a type of normal intrapulmonary membranes and can maintain the integrity of the oblique fissures and hilar structure. (orig.)

Comparison of the image quality between volumetric and conventional high-resolution CT with 64-slice row CT

International Nuclear Information System (INIS)

Gao Yanli; Zhang Lei; Zhao Xia; Ma Min; Zhai Renyou

2008-01-01

Objective: To compare the image quality between volumetric high-resolution CT (VHRCT) and conventional high-resolution CT (CHRCT), and investigate the feasibility of VHRCT. Methods: Catphan 412 phantom was scanned with protocols of CHRCT and VHRCT on a set of GE Lightspeed VCT. The spatial-resolution (LP/cm), noise (standard deviation in an ROI) and radiation close (CTDI) were recorded for each CT scan. Difference of noise between CHRCT and VHRCT were evaluated by paired t test. In clinical study, 32 patients were scanned with VHRCT and CHRCT protocols. The image quality of CHRCT and VHRCT was rated and compared. The quality difference between CHRCT and VHRCT was assessed by Wilcoxon paired signed rank sum test. Results: In phantom study, the in-plane spatial-resolution of both VHRCT and CHRCT was 11 LP/cm for axial images and 12 LP/cm for coronal reformatted images. The noise of VHRCT and CHRCT was (69.18±2.77)HU and (54.62±2.12) HU respectively (t=-15.929, P 0.05). The quality assessment scores of VHRCT coronal reformatted images and CHRCT coronal reformatted images were 3.05 and 1.88 respectively with significant difference (Z= -5.088, P<0.01). Conclusion: The image quality of VHRCT cross-sectional image is similar to that of CHRCT. Multiplanar images with high resolution of VHRCT are recommended. The radiation dose of VHRCT remains to be optimized. (authors)

Correlative 3D-imaging of Pipistrellus penis micromorphology: Validating quantitative microCT images with undecalcified serial ground section histomorphology.

Science.gov (United States)

Herdina, Anna Nele; Plenk, Hanns; Benda, Petr; Lina, Peter H C; Herzig-Straschil, Barbara; Hilgers, Helge; Metscher, Brian D

2015-06-01

Detailed knowledge of histomorphology is a prerequisite for the understanding of function, variation, and development. In bats, as in other mammals, penis and baculum morphology are important in species discrimination and phylogenetic studies. In this study, nondestructive 3D-microtomographic (microCT, µCT) images of bacula and iodine-stained penes of Pipistrellus pipistrellus were correlated with light microscopic images from undecalcified surface-stained ground sections of three of these penes of P. pipistrellus (1 juvenile). The results were then compared with µCT-images of bacula of P. pygmaeus, P. hanaki, and P. nathusii. The Y-shaped baculum in all studied Pipistrellus species has a proximal base with two club-shaped branches, a long slender shaft, and a forked distal tip. The branches contain a medullary cavity of variable size, which tapers into a central canal of variable length in the proximal baculum shaft. Both are surrounded by a lamellar and a woven bone layer and contain fatty marrow and blood vessels. The distal shaft consists of woven bone only, without a vascular canal. The proximal ends of the branches are connected with the tunica albuginea of the corpora cavernosa via entheses. In the penis shaft, the corpus spongiosum-surrounded urethra lies in a ventral grove of the corpora cavernosa, and continues in the glans under the baculum. The glans penis predominantly comprises an enlarged corpus spongiosum, which surrounds urethra and baculum. In the 12 studied juvenile and subadult P. pipistrellus specimens the proximal branches of the baculum were shorter and without marrow cavity, while shaft and distal tip appeared already fully developed. The present combination with light microscopic images from one species enabled a more reliable interpretation of histomorphological structures in the µCT-images from all four Pipistrellus species. © 2015 Wiley Periodicals, Inc.

Abdominal and Pelvic CT

Medline Plus

Full Text Available ... special computer program processes this large volume of data to create two-dimensional cross-sectional images of your body, which are then displayed on a monitor. CT imaging is sometimes compared to looking into ...

Computed Tomography (CT) -- Head

Medline Plus

Full Text Available ... special computer program processes this large volume of data to create two-dimensional cross-sectional images of your body, which are then displayed on a monitor. CT imaging is sometimes compared to looking into ...

Computed Tomography (CT) -- Sinuses

Medline Plus

Full Text Available ... special computer program processes this large volume of data to create two-dimensional cross-sectional images of your body, which are then displayed on a monitor. CT imaging is sometimes compared to looking into ...

Abdominal and Pelvic CT

Medline Plus

Full Text Available ... images or pictures of the inside of the body. The cross-sectional images generated during a CT ... very much like other x-ray examinations. Different body parts absorb the x-rays in varying degrees. ...

Computed Tomography (CT) -- Head

Medline Plus

Full Text Available ... images or pictures of the inside of the body. The cross-sectional images generated during a CT ... very much like other x-ray examinations. Different body parts absorb the x-rays in varying degrees. ...

Computed Tomography (CT) -- Sinuses

Medline Plus

Full Text Available ... images or pictures of the inside of the body. The cross-sectional images generated during a CT ... very much like other x-ray examinations. Different body parts absorb the x-rays in varying degrees. ...

Impact of CT perfusion imaging on the assessment of peripheral chronic pulmonary thromboembolism: clinical experience in 62 patients

Energy Technology Data Exchange (ETDEWEB)

Le Faivre, Julien; Khung, Suonita; Faivre, Jean-Baptiste; Remy, Jacques; Remy-Jardin, Martine [University of Lille, Department of Thoracic Imaging, Hospital Calmette, Lille (France); Duhamel, Alain [University of Lille, Department of Biostatistics, Lille (France); Lamblin, Nicolas [University of Lille, Department of Cardiology, Cardiology Hospital, Lille (France)

2016-11-15

To evaluate the impact of CT perfusion imaging on the detection of peripheral chronic pulmonary embolisms (CPE). 62 patients underwent a dual-energy chest CT angiographic examination with (a) reconstruction of diagnostic and perfusion images; (b) enabling depiction of vascular features of peripheral CPE on diagnostic images and perfusion defects (20 segments/patient; total: 1240 segments examined). The interpretation of diagnostic images was of two types: (a) standard (i.e., based on cross-sectional images alone) or (b) detailed (i.e., based on cross-sectional images and MIPs). The segment-based analysis showed (a) 1179 segments analyzable on both imaging modalities and 61 segments rated as nonanalyzable on perfusion images; (b) the percentage of diseased segments was increased by 7.2 % when perfusion imaging was compared to the detailed reading of diagnostic images, and by 26.6 % when compared to the standard reading of images. At a patient level, the extent of peripheral CPE was higher on perfusion imaging, with a greater impact when compared to the standard reading of diagnostic images (number of patients with a greater number of diseased segments: n = 45; 72.6 % of the study population). Perfusion imaging allows recognition of a greater extent of peripheral CPE compared to diagnostic imaging. (orig.)

Cross-sectional imaging of large and dense materials by high energy X-ray CT using linear accelerator

International Nuclear Information System (INIS)

Kanamori, Takahiro; Kamata, Shouji; Ito, Shinichi.

1989-01-01

A prototype high energy X-ray CT (computed tomography) system has been developed which employs a linear accelerator as the X-ray source (max. photon energy: 12 MeV). One problem encountered in development of this CT system was to reduce the scattered photons from adjacent detectors, i.e. crosstalk, due to high energy X-rays. This crosstalk was reduced to 2% by means of detector shields using tungsten spacers. Spatial resolution was not affected by such small crosstalk as confirmed by numerical simulations. A second problem was to reduce the scattered photons from the test object. This was done using collimators. A third concern was to realize a wide dynamic range data processing which would allow applications to large and dense objects. This problem was solved by using a sample and hold data acquisition method to reduce the dark current of the photo detectors. The dynamic range of this system was experimentally confirmed over 60 dB. It was demonstrated that slits (width: 2 mm) in an iron object (diameter: 25 cm) could be imaged by this prototype CT system. (author)

Development of a 3-dimensional CT using an image intensifier

International Nuclear Information System (INIS)

Toyofuku, Fukai

1992-01-01

A prototype of three-dimensional CT (Fluoroscopic CT) has been developed using an image intensifier as a two-dimensional X-ray detector. A patient on a rotating table is projected onto an image intensifier by a cone beam of X-ray from the X-ray tube. A total of 390 projection images covering 180 degrees are acquired in a single scan (13 sec) and stored on a digital frame recorder (512 x 256 x 8-bit x 480). The transverse axial images are reconstructed by using the usual CT reconstruction algorithm, while longitudinal section images such as sagittal, coronal, oblique, and panoramic images are obtained by directly back-projecting the filtered projection image onto the sections. The radiation exposure was measured with an ionization chamber, and the exposure of the present fluoroscopic CT is about 10 to 20 times less than that of conventional X-ray CT. A similar monochromatic X-ray CT system has also been developed using synchrotron radiation. Large area parallel X-rays are obtained from a wiggler beam using a silicon crystal with [311] asymmetric reflection. By taking two images above and below iodine K-absorption edge (33.17 keV), iodine image is obtained. (author)

Atlas of axial, sagittal and coronal anatomy with CT and MRI

International Nuclear Information System (INIS)

Christoforidis, A.J.

1988-01-01

This book correlates CT scans and nuclear magnetic resonance images with cross sections of all parts of the body-head and neck, thorax, abdomen, male and female pelvis and extremities. Cross sections are fixed, and images are made from the sections to provide exact section-to-scan correlation. Shows all three cross-sectional axes. Includes selected pathologic cases to demonstrate technique

Piriformis muscle syndrome. A cross-sectional imaging study in 116 patients and evaluation of therapeutic outcome

Energy Technology Data Exchange (ETDEWEB)

Vassalou, Evangelia E. [Heraklion University Hospital, Department of Medical Imaging, Voutes, Crete (Greece); Katonis, Pavlos [University Hospital of Heraklion, Department of Orthopaedics, Voutes, Crete (Greece); Karantanas, Apostolos H. [Heraklion University Hospital, Department of Medical Imaging, Voutes, Crete (Greece); University of Crete, Department of Radiology, Voutes, Crete (Greece)

2018-02-15

To increase the clinical awareness of piriformis muscle syndrome (PMs) by reporting cross-sectional imaging findings, the clinical impact of imaging studies and treatment outcome. Within a 10-year-period, 116 patients referred for radiological evaluation of clinically suspected PMs, with excluded lumbar pathology related to symptomatology, were prospectively studied with MRI and/or computed tomography (CT). Piriformis muscle (PM), sciatic nerve (SN), piriformis region and sacroiliac joints were evaluated. PMs was categorised into primary/secondary, according to a reported classification system. Treatment decisions were recorded. Outcome was categorised using a 3-point-scale. Seventy-four patients (63.8%) exhibited pathologies related to PMs. Primary causes were detected in 12 and secondary in 62 patients. PM enlargement was found in 45.9% of patients, abnormal PM signal intensity/density in 40.5% and sciatic neuritis in 25.7%. Space-occupying lesions represented the most common related pathology. Treatment proved effective in 5/8 patients with primary and 34/51 patients with secondary PMs. In 34 patients, imaging revealed an unknown underlying medical condition and altered treatment planning. Secondary PMs aetiologies appear to prevail. In suspected PMs, PM enlargement represented the most common imaging finding and space-occupying lesions the leading cause. Imaging had the potential to alter treatment decisions. (orig.)

Piriformis muscle syndrome. A cross-sectional imaging study in 116 patients and evaluation of therapeutic outcome

International Nuclear Information System (INIS)

Vassalou, Evangelia E.; Katonis, Pavlos; Karantanas, Apostolos H.

2018-01-01

To increase the clinical awareness of piriformis muscle syndrome (PMs) by reporting cross-sectional imaging findings, the clinical impact of imaging studies and treatment outcome. Within a 10-year-period, 116 patients referred for radiological evaluation of clinically suspected PMs, with excluded lumbar pathology related to symptomatology, were prospectively studied with MRI and/or computed tomography (CT). Piriformis muscle (PM), sciatic nerve (SN), piriformis region and sacroiliac joints were evaluated. PMs was categorised into primary/secondary, according to a reported classification system. Treatment decisions were recorded. Outcome was categorised using a 3-point-scale. Seventy-four patients (63.8%) exhibited pathologies related to PMs. Primary causes were detected in 12 and secondary in 62 patients. PM enlargement was found in 45.9% of patients, abnormal PM signal intensity/density in 40.5% and sciatic neuritis in 25.7%. Space-occupying lesions represented the most common related pathology. Treatment proved effective in 5/8 patients with primary and 34/51 patients with secondary PMs. In 34 patients, imaging revealed an unknown underlying medical condition and altered treatment planning. Secondary PMs aetiologies appear to prevail. In suspected PMs, PM enlargement represented the most common imaging finding and space-occupying lesions the leading cause. Imaging had the potential to alter treatment decisions. (orig.)

The reliability of AO classification for distal radius fracture, using CT findings

International Nuclear Information System (INIS)

Nakanishi, Yasuaki; Ono, Hiroshi; Furuta, Kazuhiko; Fujitani, Ryoutarou; Ota, Hiroyoshi

2006-01-01

The purpose of this study was to assess the reliability of the AO (Association for the Study of Internal Fixation) classification of distal radius fracture, using plain radiographs and 2 cross-sectional computed tomographic (CT) surface images. Five observers independently classified 32 distal radius fractures into 9 groups under AO classification. We established 4 methods for observation. First, using only two-directional radiographs; second, four-directional radiographs; third, CT (axial view) with four-directional radiographs; and fourth, CT (axial and sagittal views) with four-directional radiographs. Kappa statistics were used to establish the relative level of agreement between the observers. Interobserver reliability was poor in both first and second methods in which only plain radiographs were used (κ=0.30 and 0.23, respectively). Furthermore, reliability did not increase in the third method with the addition of 1 CT surface image (κ=0.29). In the fourth method, with the addition of 2 cross-sectional CT surface images, the reliability increased to a moderate level (κ=0.44). Interobserver reliability of the AO system of the classification of distal radius fractures was observed on using 2 cross-sectional CT surface images with four-directional radiographs. (author)

Breast multidetector-row CT with histopathologic correlation

International Nuclear Information System (INIS)

Takeuchi, Makiko; Yamashita, Akiyoshi; Ohgi, Kazuyuki; Kobori, Kenichi; Furukawa, Takashi

2004-01-01

The purpose of this study was to evaluate the correlation between multidetector-row CT (MDCT) and histopathologic findings using the same MDCT image as the histopathologic cross-section. MDCT with contrast enhancement was performed in 10 patients with breast cancers (8 invasive ductal carcinomas, one invasive lobular carcinoma, and one non-invasive ductal carcinoma). We tried to reconstruct multiplanar reconstructions (MPR) in the same plane as the histopathologic cross-section, and we evaluated the histopathologic findings of the false-positive lesions. In all cases, we obtained the same MDCT image as the histopathologic cross-section. There were 10 main lesions and 18 other lesions. In the other lesions, we found no false-negative lesions and 11 false-positive lesions. False-positive lesions included periductal fibrosis, cystic change, duct papillomatosis, sclerosing adenosis, fibroadenoma, and others. Using MDCT of the breast, it is possible to obtain good correlation between CT images and histopathologic findings. MDCT is thought to be useful in the evaluation CT findings on the basis of histopathologic evidence. (author)

Three-rooted premolar analyzed by high-resolution and cone beam CT.

Science.gov (United States)

Marca, Caroline; Dummer, Paul M H; Bryant, Susan; Vier-Pelisser, Fabiana Vieira; Só, Marcus Vinicius Reis; Fontanella, Vania; Dutra, Vinicius D'avila; de Figueiredo, José Antonio Poli

2013-07-01

The aim of this study was to analyze the variations in canal and root cross-sectional area in three-rooted maxillary premolars between high-resolution computed tomography (μCT) and cone beam computed tomography (CBCT). Sixteen extracted maxillary premolars with three distinct roots and fully formed apices were scanned using μCT and CBCT. Photoshop CS software was used to measure root and canal cross-sectional areas at the most cervical and the most apical points of each root third in images obtained using the two tomographic computed (CT) techniques, and at 30 root sections equidistant from both root ends using μCT images. Canal and root areas were compared between each method using the Student t test for paired samples and 95 % confidence intervals. Images using μCT were sharper than those obtained using CBCT. There were statistically significant differences in mean area measurements of roots and canals between the μCT and CBCT techniques (P < 0.05). Root and canal areas had similar variations in cross-sectional μCT images and became proportionally smaller in a cervical to apical direction as the cementodentinal junction was approached, from where the area then increased apically. Although variation was similar in the roots and canals under study, CBCT produced poorer image details than μCT. Although CBCT is a strong diagnosis tool, it still needs improvement to provide accuracy in details of the root canal system, especially in cases with anatomical variations, such as the three-rooted maxillary premolars.

Review of Extraskeletal Activity on Tc-99m Methylene Diphosphonate Bone Scintigraphy and Value of Cross-Sectional and SPECT-CT Imaging Correlation.

Science.gov (United States)

Bermo, Mohammed; Behnia, Sanaz; Fair, Joanna; Miyaoka, Robert S; Elojeimy, Saeed

2017-07-31

Recognizing the different mechanisms and imaging appearance of extraskeletal Tc-99m methylene diphosphonate uptake enhances the diagnostic value of bone scan interpretation. In this article, we present a pictorial review of the different mechanisms of extraskeletal Tc-99m methylene diphosphonate uptake on bone scintigraphy including neoplastic, inflammatory, ischemic, traumatic, excretory, and iatrogenic. We also illustrate through case examples the added value of correlation with cross-sectional and single photon emission computed tomography and computed tomography imaging in localizing and characterizing challenging cases of extraskeletal uptake. Copyright © 2017 Elsevier Inc. All rights reserved.

An experimental study for qualitatively diagnosing stapes lesions by helical 3-dimensional CT

International Nuclear Information System (INIS)

Kawaue, Akifumi; Kuki, Kiyonori; Yamanaka, Noboru; Nishimura, Michihiko

2001-01-01

To evaluate qualitative diagnosis of stapes lesions by 3-dimensional computed tomography (3D-CT) combined with superselective image processing (3D-SS) of stapes, we studied helical 3D-CT on a phantom model of the temporal bone. Two stapes models were used-1 made from the bone filler, Celatite, consistent in bone density but changing in cross sectional area, and the other made from an apacerum rod used in quantitative computed tomography (QCT), consistent in cross sectional area but changing in bone density. These stapes models were put into a skull phantom and analyzed by helical 3D-CT. The influence of the tympanic cavity conditions on CT images of stapes was evaluated by filling the phantom model with Vaseline following 3D selective reconstruction. In all stapes models, lowering the lower CT window width threshold resulted in an enlarged cross-sectional area of the model. The higher the bone density, the lower the increase in cross-sectional area in the image. The stapes model with lower density had greater influence on the imaging by tympanic cavity conditions and was likely to be misdiagnosed as showing higher bone density. Based on the experimental study, 3D-SS by helical 3D-CT appears to be a useful measure for qualitatively diagnosing stapes lesions. (author)

Phase-contrast X-ray CT

Energy Technology Data Exchange (ETDEWEB)

Momose, Atsushi [Hitachi Ltd., Saitama (Japan). Advanced Research Laboratory; Takeda, Tohoru; Itai, Yuji

1995-12-01

Phase-contrast X-ray computed tomography (CT) enabling the observation of biological soft tissues without contrast enhancement has been developed. The X-ray phase shift caused by an object is measured and input to a standard CT reconstruction algorithm. A thousand times increase in the image sensitivity to soft tissues is achieved compared with the conventional CT using absorption contrast. This is because the X-ray phase shift cross section of light elements is about a thousand times larger than the absorption cross section. The phase shift is detected using an X-ray interferometer and computer analyses of interference patterns. Experiments were performed using a synchrotron X-ray source. Excellent image sensitivity is demonstrated in the observation of cancerous rabbit liver. The CT images distinguish cancer lesion from normal liver tissue and, moreover, visualize the pathological condition in the lesion. Although the X-ray energy employed and the present observation area size are not suitable for medical applications as they are, phase-contrast X-ray CT is promising for investigating the internal structure of soft tissue which is almost transparent for X-rays. The high sensitivity also provides the advantage of reducing X-ray doses. (author).

Extranodal lymphoma in the thorax: cross-sectional imaging findings

International Nuclear Information System (INIS)

Lee, W.-K.; Duddalwar, V.A.; Rouse, H.C.; Lau, E.W.F.; Bekhit, E.; Hennessy, O.F.

2009-01-01

The purpose of this review is to discuss and illustrate the spectrum of appearances of extranodal lymphoma in the thorax, including the lungs, pleura, heart, thymus, chest wall, thoracic spine, and breast, using current cross-sectional imaging techniques, such as multidetector computed tomography, positron-emission tomography/computed tomography, magnetic resonance imaging, and sonography. Extranodal lymphoma can affect any organ or tissue in the thorax, and can be mistaken for other inflammatory or neoplastic conditions. This review should alert the radiologist to consider extranodal lymphoma in the appropriate clinical setting to ensure timely diagnosis, correct staging, and accurate post-treatment evaluation to optimize treatment regimens.

A simple method to approximate liver size on cross-sectional images using living liver models

International Nuclear Information System (INIS)

Muggli, D.; Mueller, M.A.; Karlo, C.; Fornaro, J.; Marincek, B.; Frauenfelder, T.

2009-01-01

Aim: To assess whether a simple. diameter-based formula applicable to cross-sectional images can be used to calculate the total liver volume. Materials and methods: On 119 cross-sectional examinations (62 computed tomography and 57 magnetic resonance imaging) a simple, formula-based method to approximate the liver volume was evaluated. The total liver volume was approximated measuring the largest craniocaudal (cc), ventrodorsal (vd), and coronal (cor) diameters by two readers and implementing the equation: Vol estimated =ccxvdxcorx0.31. Inter-rater reliability, agreement, and correlation between liver volume calculation and virtual liver volumetry were analysed. Results: No significant disagreement between the two readers was found. The formula correlated significantly with the volumetric data (r > 0.85, p < 0.0001). In 81% of cases the error of the approximated volume was <10% and in 92% of cases <15% compared to the volumetric data. Conclusion: Total liver volume can be accurately estimated on cross-sectional images using a simple, diameter-based equation.

X-ray CT core imaging of Oman Drilling Project on D/V CHIKYU

Science.gov (United States)

Michibayashi, K.; Okazaki, K.; Leong, J. A. M.; Kelemen, P. B.; Johnson, K. T. M.; Greenberger, R. N.; Manning, C. E.; Harris, M.; de Obeso, J. C.; Abe, N.; Hatakeyama, K.; Ildefonse, B.; Takazawa, E.; Teagle, D. A. H.; Coggon, J. A.

2017-12-01

We obtained X-ray computed tomography (X-ray CT) images for all cores (GT1A, GT2A, GT3A and BT1A) in Oman Drilling Project Phase 1 (OmanDP cores), since X-ray CT scanning is a routine measurement of the IODP measurement plan onboard Chikyu, which enables the non-destructive observation of the internal structure of core samples. X-ray CT images provide information about chemical compositions and densities of the cores and is useful for assessing sample locations and the quality of the whole-round samples. The X-ray CT scanner (Discovery CT 750HD, GE Medical Systems) on Chikyu scans and reconstructs the image of a 1.4 m section in 10 minutes and produces a series of scan images, each 0.625 mm thick. The X-ray tube (as an X-ray source) and the X-ray detector are installed inside of the gantry at an opposing position to each other. The core sample is scanned in the gantry with the scanning rate of 20 mm/sec. The distribution of attenuation values mapped to an individual slice comprises the raw data that are used for subsequent image processing. Successive two-dimensional (2-D) slices of 512 x 512 pixels yield a representation of attenuation values in three-dimensional (3-D) voxels of 512 x 512 by 1600 in length. Data generated for each core consist of core-axis-normal planes (XY planes) of X-ray attenuation values with dimensions of 512 × 512 pixels in 9 cm × 9 cm cross-section, meaning at the dimensions of a core section, the resolution is 0.176 mm/pixel. X-ray intensity varies as a function of X-ray path length and the linear attenuation coefficient (LAC) of the target material is a function of the chemical composition and density of the target material. The basic measure of attenuation, or radiodensity, is the CT number given in Hounsfield units (HU). CT numbers of air and water are -1000 and 0, respectively. Our preliminary results show that CT numbers of OmanDP cores are well correlated to gamma ray attenuation density (GRA density) as a function of chemical

Micron-CT using quasi-monochromatic x-rays produced in micro-PIXE

International Nuclear Information System (INIS)

Ishii, K.

2009-01-01

In ion-atom collision, characteristic X-rays are intensively produced and can be considered as a monochromatic X-ray source. We apply this feature to X-ray CT. By using micro-beams, cross sectional images can be provided with a spatial resolution of about 1 μm. On the basis of this idea, we developed a micron-CT consisting of a micro-beam system and an X-ray CCD camera. A tube holding samples was rotated by a stepping motor and the transmission images of the sample were taken with characteristic K-X-rays of Ti (4.558 keV) produced by 3 MeV proton micro-beams. After image reconstruction, images of cross sections of small objects were obtained with a spatial resolution of 3 μm. Using an absorption edge, we can identify an element in a sample. It is expected that our micron-CT can provide cross sectional images of in-vivo cellular samples and can be applied to a wide range of researches in biology and medicine. (author)

Advanced imaging of the musculoskeletal system: Standard, three-dimensional, and contrast-enhanced CT and MR imaging, and quantitative bone densitometry

International Nuclear Information System (INIS)

Resnick, D.; Sartoris, D.J.

1987-01-01

This course reviews the application of advanced imaging techniques to a broad spectrum of musculoskeletal disorders. The indications for and utility of standard CT in both the axial and the appendicular skeleton is explored. The combined use of CT with air and contrast arthrography at sites including the hip, knee, and shoulder is discussed. A summary of the proved and potential applications of MR imaging in osseous, articular, bone marrow, and soft-tissue disorders is provided. The utility of intraarticular contrast agents in enhancing the diagnostic capabilities of MR imaging for disorders of hyaline cartilage and and fibrocartilage is demonstrated. The advantages of multiplanar reformation and three-dimensional image reconstruction of cross-sectional imaging data are described in conjunction with the fundamental technological principles of these strategies. Accepted methods as well as investigative techniques for the diagnosis and follow-up of metabolic bone disease are contrasted with regard to relative indications, advantages, and limitations

Impact of CT perfusion imaging on the assessment of peripheral chronic pulmonary thromboembolism: clinical experience in 62 patients.

Science.gov (United States)

Le Faivre, Julien; Duhamel, Alain; Khung, Suonita; Faivre, Jean-Baptiste; Lamblin, Nicolas; Remy, Jacques; Remy-Jardin, Martine

2016-11-01

To evaluate the impact of CT perfusion imaging on the detection of peripheral chronic pulmonary embolisms (CPE). 62 patients underwent a dual-energy chest CT angiographic examination with (a) reconstruction of diagnostic and perfusion images; (b) enabling depiction of vascular features of peripheral CPE on diagnostic images and perfusion defects (20 segments/patient; total: 1240 segments examined). The interpretation of diagnostic images was of two types: (a) standard (i.e., based on cross-sectional images alone) or (b) detailed (i.e., based on cross-sectional images and MIPs). The segment-based analysis showed (a) 1179 segments analyzable on both imaging modalities and 61 segments rated as nonanalyzable on perfusion images; (b) the percentage of diseased segments was increased by 7.2 % when perfusion imaging was compared to the detailed reading of diagnostic images, and by 26.6 % when compared to the standard reading of images. At a patient level, the extent of peripheral CPE was higher on perfusion imaging, with a greater impact when compared to the standard reading of diagnostic images (number of patients with a greater number of diseased segments: n = 45; 72.6 % of the study population). Perfusion imaging allows recognition of a greater extent of peripheral CPE compared to diagnostic imaging. • Dual-energy computed tomography generates standard diagnostic imaging and lung perfusion analysis. • Depiction of CPE on central arteries relies on standard diagnostic imaging. • Detection of peripheral CPE is improved by perfusion imaging.

Thin-section CT imaging that correlates with pulmonary function tests in obstructive airway disease

Energy Technology Data Exchange (ETDEWEB)

Arakawa, Hiroaki, E-mail: arakawa@dokkyomed.ac.jp [Department of Radiology, Dokkyo Medical University, 880 Kita-Kobayashi, Mibu, Tochigi 321-0293 (Japan); Fujimoto, Kiminori [Department of Radiology, Kurume University School of Medicine (Japan); Fukushima, Yasutugu [Department of Pulmonary Medicine and Clinical Immunology, Dokkyo Medical University (Japan); Kaji, Yasushi [Department of Radiology, Dokkyo Medical University, 880 Kita-Kobayashi, Mibu, Tochigi 321-0293 (Japan)

2011-11-15

Purpose: The purpose of this study was to identify independent CT findings that correlated with pulmonary function tests (PFTs) in patients with obstructive airway diseases. Materials and methods: Sixty-eight patients with obstructive airway disease and 29 normal subjects (mean age, 52 years; 36 men and 61 women) underwent inspiratory and expiratory thin-section CT and PFTs. Patient with obvious emphysema was excluded. Two radiologists independently reviewed the images and semi-quantitatively evaluated lung attenuation (mosaic perfusion, air trapping) and airway abnormalities (extent and severity of bronchial wall thickening and bronchiectasis, bronchiolectasis or centrilobular nodules, mucous plugging). Univariate, multivariate and receiver operating characteristic (ROC) analyses were performed with CT findings and PFTs. Results: Forty-two patients showed obstructive PFTs, 26 symptomatic patients showed near-normal PFTs. On univariate analysis, air trapping and bronchial wall thickening showed highest correlation with obstructive PFTs such as FEV1.0/FVC, MMEF and FEF75 (r ranged from -0.712 to -0.782; p < 0.001), while mosaic perfusion and mucous plugging showed moderate correlation, and bronchiectasis, bronchiolectasis and nodules showed the least, but significant, correlation. Multiple logistic analyses revealed air trapping and bronchial wall thickening as the only significant independent determinants of obstructive PFTs. ROC analysis revealed the cut-off value of air trapping for obstructive PFTs to be one-third of whole lung (area under curve, 0.847). Conclusions: Our study confirmed air trapping and bronchial wall thickening are the most important observations when imaging obstructive PFTs. The cut-off value of air trapping for identifying obstructive PFTs was one-third of lung irrespective of inspiratory CT findings.

A Novel Procedure for Rapid Imaging of Adult Mouse Brains with MicroCT Using Iodine-Based Contrast.

Directory of Open Access Journals (Sweden)

Ryan Anderson

Full Text Available High-resolution Magnetic Resonance Imaging (MRI has been the primary modality for obtaining 3D cross-sectional anatomical information in animals for soft tissue, particularly brain. However, costs associated with MRI can be considerably high for large phenotypic screens for gross differences in the structure of the brain due to pathology and/or experimental manipulations. MicroCT (mCT, especially benchtop mCT, is becoming a common laboratory equipment with throughput rates equal or faster than any form of high-resolution MRI at lower costs. Here we explore adapting previously developed contrast based mCT to image adult mouse brains in-situ. We show that 2% weight per volume (w/v iodine-potassium iodide solution can be successfully used to image adult mouse brains within 48 hours post-mortem when a structural support matrix is used. We demonstrate that hydrogel can be effectively used as a perfusant which limits the tissue shrinkage due to iodine.

Patterns of Hepatosplenic Brucella Abscesses on Cross-Sectional Imaging: A Review of Clinical and Imaging Features

NARCIS (Netherlands)

Heller, Tom; Bélard, Sabine; Wallrauch, Claudia; Carretto, Edoardo; Lissandrin, Raffaella; Filice, Carlo; Brunetti, Enrico

2015-01-01

While diffuse involvement of liver and spleen is frequently seen in brucellosis, suppurative abscesses caused by Brucella are less common but well described. With the increased availability of cross-sectional imaging techniques, reports have become more frequent. Four patients with hepatosplenic

Intrathoracic kidney. Diagnostic value of CT scan imaging

International Nuclear Information System (INIS)

Baillet, A.M.; Escure, M.N.

1988-01-01

Two cases are reported of an ectopic right kidney that was partially intrathoracic in position. Diagnosis was simple from CT scan imaging appearances, the examination being performed to investigate an intrathoracic mass. Images showed a tissular mass within a fatty zone in sections without contrast and the typical appearance of the kidney on sections with contrast [fr

Development of planar CT system for multi-layer PCB inspection

Energy Technology Data Exchange (ETDEWEB)

Kim, Seung Ho; Youn, Hanbean; Kam, Soohwa; Park, Eunpyeong; Kim, Ho Kyung [Pusan National University, Busan (Korea, Republic of)

2015-05-15

X-ray defect inspection apparatus can be used in the production line to inspect the PCB. However, a simple X-ray radiography cannot discriminate defects from the multi-layer PCBs because the layers of them overlays the defects. To complement this issue, computed tomography (CT) technology is applied to the NDT system which can offer 3-dimensional information of object. However, CT requires hundreds of projection images to examine a single PCB, hence real-time inspection is nearly impossible. In this study, we develop a planar computed tomography (pCT) system appropriate for the multi-layer PCB inspection. For the image reconstruction of planar cross-section images, we use the digital tomosynthesis (DTS) concept in association with the limited angle scanning. and performance characterization of the pCT system for the PCB inspection. The 3-d Fourier characteristics and more quantitative performance, such as contrast, uniformity, depth resolution will be presented. The cross-sectional images of multi-layer PCBs will also be demonstrated.

Computed Tomography (CT) -- Head

Medline Plus

Full Text Available ... therapy for brain cancer. In emergency cases, it can reveal internal injuries and bleeding quickly enough to ... cross-sectional images generated during a CT scan can be reformatted in multiple planes, and can even ...

Abdominal and Pelvic CT

Medline Plus

Full Text Available ... painless, noninvasive and accurate. In emergency cases, it can reveal internal injuries and bleeding quickly enough to ... cross-sectional images generated during a CT scan can be reformatted in multiple planes, and can even ...

Thin-section multiplanar reformats from multidetector-row CT data: Utility for assessment of regional tumor extent in non-small cell lung cancer

International Nuclear Information System (INIS)

Higashino, Takanori; Ohno, Yoshiharu; Takenaka, Daisuke; Watanabe, Hirokazu; Nogami, Munenobu; Ohbayashi, Chiho; Yoshimura, Masahiro; Satouchi, Miyako; Nishimura, Yoshihiro; Fujii, Masahiko; Sugimura, Kazuro

2005-01-01

Purpose: To determine the clinical utility of thin-section multiplanar reformats (MPRs) from multidetector-row CT (MDCT) data sets for assessing the extent of regional tumors in non-small cell lung cancer (NSCLC) patients. Materials and methods: Sixty consecutive NSCLC patients, who were considered candidates for surgical treatment, underwent contrast-enhanced MDCT examinations, surgical resection and pathological examinations. All MDCT examinations were performed with a 4-detector row computed tomography (CT). From each raw CT data set, 5 mm section thickness CT images (routine CT), 1.25 mm section thickness CT images (thin-section CT) and 1.25 mm section thickness sagittal (thin-section sagittal MPR) and coronal images (thin-section coronal MPR) were reconstructed. A 4-point visual score was used to assess mediastinal, interlobar and chest wall invasions on each image set. For assessment of utility in routine clinical practice, mean reading times for each image set were compared by means of Fisher's protected least significant difference (PLSD) test. A receiver operator characteristic (ROC) analysis was performed to determine the diagnostic capability of each of the image data sets. Finally, sensitivity, specificity and accuracy of the reconstructed images were compared by McNemar test. Results: Mean reading times for thin-section sagittal and coronal MPRs were significantly shorter than those for routine CT and thin-section CT (p < 0.05). Areas under the curve (Azs) showing interlobar invasion on thin-section sagittal and coronal MPRs were significantly larger than that on routine CT (p = 0.03), and the Az on thin-section sagittal MPR was also significantly larger than that on routine CT (p = 0.02). Accuracy of chest wall invasion by thin-section sagittal MPR was significantly higher than that by routine CT (p = 0.04). Conclusion: Thin-section multiplanar reformats from multidetector-row CT data sets are useful for assessing the extent of regional tumors in non

Cardiodiagnostic imaging. MRT, CT, echocardiography and other methods

International Nuclear Information System (INIS)

Erbel, R.; Kreitner, K.F.; Barkhausen, J.; Thelen, M.

2007-01-01

The book presents a differentiated approach to cardiac imaging. The focus is n cardio-MR/-CT and echocardiography. These are highly complex methods involving new equipment, new protocols and indications. The techniques are new and difficult to learn for everybody concerned. MR, CT and echocardiography must always be viewed in the context of other diagnostic methods. The interdisciplinary approach of the book addresses both radiologists and cardiologists and relies on the vast experience of the authors. The book offers more than 500 large high-quality reference images reflecting the latest state of the art. It has amethodological section in which the current methods are described (X-ray, echocardiography, nuclear medicine, angiography, CT, MRT etc.) along with their advantages and shortcomings, and a clinical section in which the main indications are described in the common standardized way (anatomy, clinical picture, interpretation, differential diagnosis). (orig.)

Combined SPECT/CT and PET/CT for breast imaging

Energy Technology Data Exchange (ETDEWEB)

Russo, Paolo [Università di Napoli Federico II, Dipartimento di Fisica, Via Cintia, Naples I-80126 (Italy); INFN Sezione di Napoli, Via Cintia, Naples I-80126 (Italy); Larobina, Michele [Istituto di Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche, Via Tommaso De Amicis, 95, Naples I-80145 (Italy); Di Lillo, Francesca [Università di Napoli Federico II, Dipartimento di Fisica, Via Cintia, Naples I-80126 (Italy); INFN Sezione di Napoli, Via Cintia, Naples I-80126 (Italy); Del Vecchio, Silvana [Università di Napoli Federico II, Dipartimento di Scienze Biomediche Avanzate, Via Pansini, 5, Naples I-80131 (Italy); Mettivier, Giovanni, E-mail: mettivier@na.infn.it [Università di Napoli Federico II, Dipartimento di Fisica, Via Cintia, Naples I-80126 (Italy); INFN Sezione di Napoli, Via Cintia, Naples I-80126 (Italy)

2016-02-11

In the field of nuclear medicine imaging, breast imaging for cancer diagnosis is still mainly based on 2D imaging techniques. Three-dimensional tomographic imaging with whole-body PET or SPECT scanners, when used for imaging the breast, has performance limits in terms of spatial resolution and sensitivity, which can be overcome only with a dedicated instrumentation. However, only few hybrid imaging systems for PET/CT or SPECT/CT dedicated to the breast have been developed in the last decade, providing complementary functional and anatomical information on normal breast tissue and lesions. These systems are still under development and clinical trials on just few patients have been reported; no commercial dedicated breast PET/CT or SPECT/CT is available. This paper reviews combined dedicated breast PET/CT and SPECT/CT scanners described in the recent literature, with focus on their technological aspects.

Clinical and CT imaging features of abdominal fat necrosis

International Nuclear Information System (INIS)

Zhao Jinkun; Bai Renju

2013-01-01

Fat necrosis is a common pathological change at abdominal cross-sectional imaging, and it may cause abdominal pain, mimic pathological change of acute abdomen, or be asymptomatic and accompany other pathophysiologic processes. Fat necrosis is actually the result of steatosis by metabolism or mechanical injury. Common processes that are present in fat necrosis include epiploic appendagitis, infarction of the greater omentum, pancreatitis, and fat necrosis related to trauma or ischemia. As a common fat disease, fat necrosis should be known by clinicians and radiologists. Main content of this text is the clinical symptoms and CT findings of belly fat necrosis and related diseases. (authors)

Dynamic CT Perfusion Imaging for the Detection of Crossed Cerebellar Diaschisis in Acute Ischemic Stroke

International Nuclear Information System (INIS)

Jeon, Young Wook; Kim, Seo Hyun; Lee, Ji Young; Whang, Kum; Kim, Myung Soon; Kim, Young Ju; Lee, Myeong Sub; Brain Reserch Group

2012-01-01

Although the detection of crossed cerebellar diaschisis (CCD) by means of different imaging modalities is well described, little is known about its diagnosis by computed tomography perfusion (CTP) imaging. We investigated the detection rate of CCD by CTP imaging and the factors related to CCD on CTP images in patients with acute ischemic stroke. CT perfusion maps of cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), and time-to-peak (TTP) obtained from 81 consecutive patients affected by an acute ischemic stroke were retrospectively reviewed. Whole-brain perfusion maps were obtained with a multichannel CT scanner using the toggling-table technique. The criteria for CCD was a unilateral supratentorial ischemic lesion and an accompanying decrease in perfusion of the contralateral cerebellar hemisphere on the basis of CTP maps by visual inspection without a set threshold. Maps were quantitatively analyzed in CCD positive cases. The criteria for CCD were fulfilled in 25 of the 81 cases (31%). Detection rates per CTP map were as follows: MTT (31%) > TTP (21%) > CBF (9%) > CBV (6%). Supratentorial ischemic volume, degree of perfusion reduction, and infratentorial asymmetry index correlated strongly (R, 0.555-0.870) and significantly (p < 0.05) with each other in CCD-positive cases. It is possible to detect CCD on all four of the CTP-based maps. Of these maps, MTT is most sensitive in detecting CCD. Our data indicate that CTP imaging is a valid tool for the diagnosis of CCD in patients affected by an acute hemispheric stroke.

Cross-sectional imaging of complicated urinary infections affecting the lower tract and male genital organs

Directory of Open Access Journals (Sweden)

Massimo Tonolini

2016-06-01

Full Text Available Abstract Complicated urinary tract infections (C-UTIs are those associated with structural or functional genitourinary abnormalities or with conditions that impair the host defence mechanisms, leading to an increased risk of acquiring infection or failing therapy. C-UTIs occur in patients with risk factors such as neurogenic dysfunction, bladder outlet obstruction, obstructive uropathy, bladder catheterisation, urologic instrumentation or indwelling stent, urinary tract post-surgical modifications, chemotherapy- or radiation-induced damage, renal impairment, diabetes and immunodeficiency. Multidetector CT and MRI allow comprehensive investigation of C-UTIs and systemic infection from an unknown source. Based upon personal experience at a tertiary care hospital focused on the treatment of infectious illnesses, this pictorial essay reviews with examples the clinical features and cross-sectional imaging findings of C-UTIs affecting the lower urinary tract and male genital organs. The disorders presented include acute infectious cystitis, bladder mural abscesses, infections of the prostate and seminal vesicles, acute urethritis and related perineal abscesses, funiculitis, epididymo-orchitis and scrotal abscesses. Emphasis is placed on the possible differential diagnoses of lower C-UTIs. The aim is to provide radiologists greater familiarity with these potentially severe disorders which frequently require intensive in-hospital antibiotic therapy, percutaneous drainage or surgery. Teaching Points • Complicated urinary tract infections occur in patients with structural or functional risk factors. • CT and MRI comprehensively investigate complicated urinary infections and sepsis from unknown sources. • Infections of the urinary bladder, prostate, seminal vesicles, urethra and scrotum are presented. • Emphasis is placed on differential diagnoses of complicated lower urogenital infections. • Unsuspected urinary infections may be detected on CT

The relationship between image quality and CT dose index of multi-slice low-dose chest CT

International Nuclear Information System (INIS)

Zhu Xiaohua; Shao Jiang; Shi Jingyun; You Zhengqian; Li Shijun; Xue Yongming

2003-01-01

Objective: To explore the rationality and possibility of multi-slice low-dose CT scan in the examination of the chest. Methods: (1) X-ray dose index measurement: 120 kV tube voltage, 0.75 s rotation, 8 mm and 3 mm slice thickness, and the tube current setting of 115.0, 40.0, 25.0, and 7.5 mAs were employed in every section. The X-ray radiation dose was measured and compared statistically. (2) phantom measurement of homogeneity and noise: The technical parameters were 120 kV, 0.75 s, 8 mm and 3 mm sections, and every slice was scanned using tube current of 115.0, 40.0, 25.0, and 7.5 mAs. Five same regions of interest were measured on every image. The homogeneity and noise level of CT were appraised. (3) The multi-slice low-dose CT in patients: 30 patients with mass and 30 with patch shadow in the lung were selected randomly. The technical parameters were 120 kV, 0.75 s, 8 mm and 3 mm slice thickness. 115.0, 40.0, 25.0, 15.0, and 7.5 mAs tube current were employed in each same slice. Otherwise, 15 cases with helical scan were examined using 190, 150, 40, 25, and 15 mAs tube current. The reconstruction images of MIP, MPR, CVR, HRCT, 3D, CT virtual endoscopy, and variety of interval reconstruction were compared. (4) Evaluation of image quality: CT images were evaluated by four doctors using single-blind method, and 3 degrees including normal image, image with few artifact, and image with excessive artifact, were employed and analyzed statistically. Results: (1) The CT dose index with 115.0 mAs tube current exceeded those of 40.0, 25.0, and 7.5 mAs by about 60%, 70%, and 85%, respectively. (2) The phantom measurement showed that the lower of CT dose the lower of homogeneity, the lower of CT dose the higher of noise level. (3) Result of image quality evaluation: The percentage of the normal image had no significant difference between 8 and 3 mm in 115, 40, and 25 mAs (P>0.05). Conclusion: Multi-slice low-dose chest CT technology may protect the patients and guarantee the

Cross-sectional imaging of the Fontan circuit in adult congenital heart disease

International Nuclear Information System (INIS)

Lewis, G.; Thorne, S.; Clift, P.; Holloway, B.

2015-01-01

The Fontan circuit is the result of a palliative surgical procedure that is performed in patients with a functionally single ventricle cardiac anomaly. The success of this operation has resulted in an increasing population of adults with this anatomy and physiology. The purpose of this article is to familiarize the general radiologist with the expected anatomy and cross-sectional imaging findings, highlight special imaging considerations, and examine the common complications that are encountered in this group of patients

Transconvolution and the virtual positron emission tomograph—A new method for cross calibration in quantitative PET/CT imaging

International Nuclear Information System (INIS)

Prenosil, George A.; Weitzel, Thilo; Hentschel, Michael; Klaeser, Bernd; Krause, Thomas

2013-01-01

Gaussian distribution were introduced. Furthermore, simulation of a virtual PET system provided a standard imaging system with clearly defined properties to which the real PET systems were to be matched. A Hann window served as the modulation transfer function for the virtual PET. The Hann's apodization properties suppressed high spatial frequencies above a certain critical frequency, thereby fulfilling the above-mentioned boundary conditions. The determined point spread functions were subsequently used by the novel Transconvolution algorithm to match different PET/CT systems onto the virtual PET system. Finally, the theoretically elaborated Transconvolution method was validated transforming phantom images acquired on two different PET systems to nearly identical data sets, as they would be imaged by the virtual PET system. Results: The proposed Transconvolution method matched different PET/CT-systems for an improved and reproducible determination of a normalized activity concentration. The highest difference in measured activity concentration between the two different PET systems of 18.2% was found in spheres of 2 ml volume. Transconvolution reduced this difference down to 1.6%. In addition to reestablishing comparability the new method with its parameterization of point spread functions allowed a full characterization of imaging properties of the examined tomographs. Conclusions: By matching different tomographs to a virtual standardized imaging system, Transconvolution opens a new comprehensive method for cross calibration in quantitative PET imaging. The use of a virtual PET system restores comparability between data sets from different PET systems by exerting a common, reproducible, and defined partial volume effect.

Panoramic three-dimensional CT imaging

International Nuclear Information System (INIS)

Kawamata, Akitoshi; Fujishita, Masami

1998-01-01

Panoramic radiography is a unique projection technique for producing a single image of both maxillary and mandibular arches and many other anatomical structures. To obtain a similar panoramic image without panoramic radiography system, a modified three-dimensional (3D) CT imaging technique was designed. A set of CT slice image data extending from the chin to the orbit was used for 3D reconstruction. The CT machine used in this study was the X-Vision (TOSHIBA, Japan). The helical scan technique was used. The slice thickness of reconstructed image was one or 1.5 mm. The occlusal plane or Frankfort horizontal (FH) plane was used as the reference line. The resultant slice image data was stored on a magnetic optical disk and then used to create panoramic 3D-CT images on a Macintosh computer systems (Power Macintosh 8600/250, Apple Computer Inc., USA). To create the panoramic 3D-CT image, the following procedure was designed: Design a curved panoramic 3D-CT imaging layer using the imaging layer and the movement of the x-ray beam in panoramic radiography system as a template; Cut this imaging layer from each slice image, then the trimmed image was transformed to a rectangular layer using the ''still image warping'' special effect in the Elastic Reality special effects system (Elastic Reality Inc., USA); Create panoramic 3D-CT image using the Voxel View (Vital Images Inc., USA) rendering system and volume rendering technique. Although the image quality was primitive, a panoramic view of maxillofacial region was obtained by this technique. (author)

Lung cancer mimicking lung abscess formation on CT images.

Science.gov (United States)

Taira, Naohiro; Kawabata, Tsutomu; Gabe, Atsushi; Ichi, Takaharu; Kushi, Kazuaki; Yohena, Tomofumi; Kawasaki, Hidenori; Yamashiro, Toshimitsu; Ishikawa, Kiyoshi

2014-01-01

Male, 64 FINAL DIAGNOSIS: Lung pleomorphic carcinoma Symptoms: Cough • fever - Clinical Procedure: - Specialty: Oncology. Unusual clinical course. The diagnosis of lung cancer is often made based on computed tomography (CT) image findings if it cannot be confirmed on pathological examinations, such as bronchoscopy. However, the CT image findings of cancerous lesions are similar to those of abscesses.We herein report a case of lung cancer that resembled a lung abscess on CT. We herein describe the case of 64-year-old male who was diagnosed with lung cancer using surgery. In this case, it was quite difficult to distinguish between the lung cancer and a lung abscess on CT images, and a lung abscess was initially suspected due to symptoms, such as fever and coughing, contrast-enhanced CT image findings showing a ring-enhancing mass in the right upper lobe and the patient's laboratory test results. However, a pathological diagnosis of lung cancer was confirmed according to the results of a rapid frozen section biopsy of the lesion. This case suggests that physicians should not suspect both a lung abscesses and malignancy in cases involving masses presenting as ring-enhancing lesions on contrast-enhanced CT.

CT image reconstruction of steel pipe section from few projections using the method of rotating polar-coordinate

International Nuclear Information System (INIS)

Peng Shuaijun; Wu Zhifang

2008-01-01

Fast online inspection in steel pipe production is a big challenge. Radiographic CT imaging technology, a high performance non-destructive testing method, is quite appropriate for inspection and quality control of steel pipes. The method of rotating polar-coordinate is used to reconstruct the steel pipe section from few projections with the purpose of inspecting it online. It reduces the projection number needed and the data collection time, and accelerates the reconstruction algorithm and saves the inspection time evidently. The results of simulation experiment and actual experiment indicate that the image quality and reconstruction time of rotating polar-coordinate method meet the requirements of inspecting the steel tube section online basically. The study is of some theoretical significance and the method is expected to be widely used in practice. (authors)

Measurements of angles of the normal auditory ossicles relative to the reference plane and image reconstruction technique for obtaining optimal sections of the ossicles in high-resolution multiplanar reconstruction using a multislice CT scanner

International Nuclear Information System (INIS)

Fujii, Naoko; Katada, Kazuhiro; Yoshioka, Satoshi; Takeuchi, Kenji; Takasu, Akihiko; Naito, Kensei

2005-01-01

Using high-resolution isotropic volume data obtained by 0.5 mm, 4-row multislice CT, cross-sectional observation of the auditory ossicles is possible from any desired direction without difficulty in high-resolution multiplanar reconstruction (HR-MPR) images, also distortion-free three-dimensional images of the ossicles are generated in three-dimensional CT (3D-CT) images. We measured angles of fifty normal ossicles relative to the reference plane, which has been defined as a plane through the bilateral infraorbital margins to the middle portion of the external auditory canal. Based on the results of angle measurement, four optimal sections of the ossicles for efficient viewing to the ossicular chain were identified. To understand the position of the angle measurement and the four sections, the ossicles and the reference plane were reconstructed in the 3D-CT images. As the result of observation of the ossicles and the reference plane, the malleus was parallel to the incudal long process and perpendicular to the reference plane. As the results of angle measurement, the mean angle of the tympanic portion of the facial nerve relative to the reference plane in the sagittal plane was found to be 17 deg, and the mean angle of the stapedial crura relative to the reference plane in the sagittal plane was found to be 6 deg. The mean angle of the stapes relative to the reference plane in the coronal plane was 44 deg, and the mean angle of the incudal long process relative to the stapes in the coronal plane was 89 deg. In 80% of ears, the stapes extended straight from the incudal long process. Image reconstruction technique for viewing four sections of the ossicles was investigated. Firstly, the image of the malleal head and the incudal short process was identified in the axial plane. Secondly, an image of the malleus along the malleal manubrium was reconstructed in the coronal plane. Thirdly, the image of the incudal long process was seen immediately behind the malletis image

Mediastinal and hilar lymphadenopathy: cross-referenced anatomy on axial and coronal images displayed by using multi-detector row CT

International Nuclear Information System (INIS)

Lee, Ju Hyun; Lee, Kyung Soo; Kim, Tae Sung; Yi, Chin A; Cho, Jae Min; Lee, Min Hee

2003-01-01

The accurate evaluation of mediastinal and pulmonary hilar lymphadenopathy, especially in patients with lung cancer, is important for determining treatment options and evaluating the response to therapy. To indicate nodal location in detail, mediastinal and hilar lymph nodes have been assigned to one of 14 nodal stations. Mediastinal nodes of greater than 10 mm short-axis diameter are regarded as abnormal, irrespective of their nodal station, while hilar nodes are considered abnormal if their diameter is greater than 10 mm in any axis or they are convex compared to surrounding lung. By providing multiplanar images, multi-detector row CT allows detailed evaluation of thoracic anatomic structures more easily than in the past, when axial images only were available. At cross-referenced imaging, a lymph node depicted at axial imaging in one anatomical location can be visualized simultaneously and automatically at coronal imaging at the exactly corresponding anatomical location. Cross-referenced coincidental axial and coronal images help assess both the size and morphology of mediastinal and hilar lymph nodes

Localized thin-section CT with radiomics feature extraction and machine learning to classify early-detected pulmonary nodules from lung cancer screening

Science.gov (United States)

Tu, Shu-Ju; Wang, Chih-Wei; Pan, Kuang-Tse; Wu, Yi-Cheng; Wu, Chen-Te

2018-03-01

Lung cancer screening aims to detect small pulmonary nodules and decrease the mortality rate of those affected. However, studies from large-scale clinical trials of lung cancer screening have shown that the false-positive rate is high and positive predictive value is low. To address these problems, a technical approach is greatly needed for accurate malignancy differentiation among these early-detected nodules. We studied the clinical feasibility of an additional protocol of localized thin-section CT for further assessment on recalled patients from lung cancer screening tests. Our approach of localized thin-section CT was integrated with radiomics features extraction and machine learning classification which was supervised by pathological diagnosis. Localized thin-section CT images of 122 nodules were retrospectively reviewed and 374 radiomics features were extracted. In this study, 48 nodules were benign and 74 malignant. There were nine patients with multiple nodules and four with synchronous multiple malignant nodules. Different machine learning classifiers with a stratified ten-fold cross-validation were used and repeated 100 times to evaluate classification accuracy. Of the image features extracted from the thin-section CT images, 238 (64%) were useful in differentiating between benign and malignant nodules. These useful features include CT density (p  =  0.002 518), sigma (p  =  0.002 781), uniformity (p  =  0.032 41), and entropy (p  =  0.006 685). The highest classification accuracy was 79% by the logistic classifier. The performance metrics of this logistic classification model was 0.80 for the positive predictive value, 0.36 for the false-positive rate, and 0.80 for the area under the receiver operating characteristic curve. Our approach of direct risk classification supervised by the pathological diagnosis with localized thin-section CT and radiomics feature extraction may support clinical physicians in determining

RootAnalyzer: A Cross-Section Image Analysis Tool for Automated Characterization of Root Cells and Tissues.

Directory of Open Access Journals (Sweden)

Joshua Chopin

Full Text Available The morphology of plant root anatomical features is a key factor in effective water and nutrient uptake. Existing techniques for phenotyping root anatomical traits are often based on manual or semi-automatic segmentation and annotation of microscopic images of root cross sections. In this article, we propose a fully automated tool, hereinafter referred to as RootAnalyzer, for efficiently extracting and analyzing anatomical traits from root-cross section images. Using a range of image processing techniques such as local thresholding and nearest neighbor identification, RootAnalyzer segments the plant root from the image's background, classifies and characterizes the cortex, stele, endodermis and epidermis, and subsequently produces statistics about the morphological properties of the root cells and tissues. We use RootAnalyzer to analyze 15 images of wheat plants and one maize plant image and evaluate its performance against manually-obtained ground truth data. The comparison shows that RootAnalyzer can fully characterize most root tissue regions with over 90% accuracy.

PET/CT (and CT) instrumentation, image reconstruction and data transfer for radiotherapy planning

International Nuclear Information System (INIS)

Sattler, Bernhard; Lee, John A.; Lonsdale, Markus; Coche, Emmanuel

2010-01-01

The positron emission tomography in combination with CT in hybrid, cross-modality imaging systems (PET/CT) gains more and more importance as a part of the treatment-planning procedure in radiotherapy. Positron emission tomography (PET), as a integral part of nuclear medicine imaging and non-invasive imaging technique, offers the visualization and quantification of pre-selected tracer metabolism. In combination with the structural information from CT, this molecular imaging technique has great potential to support and improve the outcome of the treatment-planning procedure prior to radiotherapy. By the choice of the PET-Tracer, a variety of different metabolic processes can be visualized. First and foremost, this is the glucose metabolism of a tissue as well as for instance hypoxia or cell proliferation. This paper comprises the system characteristics of hybrid PET/CT systems. Acquisition and processing protocols are described in general and modifications to cope with the special needs in radiooncology. This starts with the different position of the patient on a special table top, continues with the use of the same fixation material as used for positioning of the patient in radiooncology while simulation and irradiation and leads to special processing protocols that include the delineation of the volumes that are subject to treatment planning and irradiation (PTV, GTV, CTV, etc.). General CT acquisition and processing parameters as well as the use of contrast enhancement of the CT are described. The possible risks and pitfalls the investigator could face during the hybrid-imaging procedure are explained and listed. The interdisciplinary use of different imaging modalities implies a increase of the volume of data created. These data need to be stored and communicated fast, safe and correct. Therefore, the DICOM-Standard provides objects and classes for this purpose (DICOM RT). Furthermore, the standard DICOM objects and classes for nuclear medicine (NM, PT) and

CT of the heart

International Nuclear Information System (INIS)

Lipton, M.J.

1986-01-01

Advances based upon the detector elements instead of X-ray film have greatly increased the power of X-ray imaging. Computed tomography (CT) creates cross sectional rather than projected images. Recently, high speed CT devices have been developed for cardiovascular studies. The Cine-CT scanner employs a scanning electron beam deflected on an extended tungsten target ring. Fast scans of 50 millisecond exposures at multiple levels can provide information concerning blood flow in vessels and tissues, myocardial wall motion, valve integrity, coronary bypass graft patency and proximal coronary artery anatomy. Cine-CT dynamic scanning can also provide volume imaging with small quantities (0.05 - 1.5 ml/kg) of contrast medium administered via peripheral vein injections. Cine-CT provides simultaneous measurements of cardiac dimensions and function and is rapidly becoming a new tool for quantitating myocardial blood flow, cardiac chamber volumes and wall mechanics. The future outlook is very promising for this three-dimensional cine-CT technique with high spatial resolution. High speed CT should provide unique diagnostic information and as the technology continues to improve at a rapid speed, this new imaging modality could be a challenge for angiography. (Auth.)

Simultaneous Reduction in Noise and Cross-Contamination Artifacts for Dual-Energy X-Ray CT

Directory of Open Access Journals (Sweden)

Baojun Li

2013-01-01

Full Text Available Purpose. Dual-energy CT imaging tends to suffer from much lower signal-to-noise ratio than single-energy CT. In this paper, we propose an improved anticorrelated noise reduction (ACNR method without causing cross-contamination artifacts. Methods. The proposed algorithm diffuses both basis material density images (e.g., water and iodine at the same time using a novel correlated diffusion algorithm. The algorithm has been compared to the original ACNR algorithm in a contrast-enhanced, IRB-approved patient study. Material density accuracy and noise reduction are quantitatively evaluated by the percent density error and the percent noise reduction. Results. Both algorithms have significantly reduced the noises of basis material density images in all cases. The average percent noise reduction is 69.3% and 66.5% with the ACNR algorithm and the proposed algorithm, respectively. However, the ACNR algorithm alters the original material density by an average of 13% (or 2.18 mg/cc with a maximum of 58.7% (or 8.97 mg/cc in this study. This is evident in the water density images as massive cross-contaminations are seen in all five clinical cases. On the contrary, the proposed algorithm only changes the mean density by 2.4% (or 0.69 mg/cc with a maximum of 7.6% (or 1.31 mg/cc. The cross-contamination artifacts are significantly minimized or absent with the proposed algorithm. Conclusion. The proposed algorithm can significantly reduce image noise present in basis material density images from dual-energy CT imaging, with minimized cross-contaminations compared to the ACNR algorithm.

Volumetric CT-images improve testing of radiological image interpretation skills

Energy Technology Data Exchange (ETDEWEB)

Ravesloot, Cécile J., E-mail: C.J.Ravesloot@umcutrecht.nl [Radiology Department at University Medical Center Utrecht, Heidelberglaan 100, 3508 GA Utrecht, Room E01.132 (Netherlands); Schaaf, Marieke F. van der, E-mail: M.F.vanderSchaaf@uu.nl [Department of Pedagogical and Educational Sciences at Utrecht University, Heidelberglaan 1, 3584 CS Utrecht (Netherlands); Schaik, Jan P.J. van, E-mail: J.P.J.vanSchaik@umcutrecht.nl [Radiology Department at University Medical Center Utrecht, Heidelberglaan 100, 3508 GA Utrecht, Room E01.132 (Netherlands); Cate, Olle Th.J. ten, E-mail: T.J.tenCate@umcutrecht.nl [Center for Research and Development of Education at University Medical Center Utrecht, Heidelberglaan 100, 3508 GA Utrecht (Netherlands); Gijp, Anouk van der, E-mail: A.vanderGijp-2@umcutrecht.nl [Radiology Department at University Medical Center Utrecht, Heidelberglaan 100, 3508 GA Utrecht, Room E01.132 (Netherlands); Mol, Christian P., E-mail: C.Mol@umcutrecht.nl [Image Sciences Institute at University Medical Center Utrecht, Heidelberglaan 100, 3508 GA Utrecht (Netherlands); Vincken, Koen L., E-mail: K.Vincken@umcutrecht.nl [Image Sciences Institute at University Medical Center Utrecht, Heidelberglaan 100, 3508 GA Utrecht (Netherlands)

2015-05-15

Rationale and objectives: Current radiology practice increasingly involves interpretation of volumetric data sets. In contrast, most radiology tests still contain only 2D images. We introduced a new testing tool that allows for stack viewing of volumetric images in our undergraduate radiology program. We hypothesized that tests with volumetric CT-images enhance test quality, in comparison with traditional completely 2D image-based tests, because they might better reflect required skills for clinical practice. Materials and methods: Two groups of medical students (n = 139; n = 143), trained with 2D and volumetric CT-images, took a digital radiology test in two versions (A and B), each containing both 2D and volumetric CT-image questions. In a questionnaire, they were asked to comment on the representativeness for clinical practice, difficulty and user-friendliness of the test questions and testing program. Students’ test scores and reliabilities, measured with Cronbach's alpha, of 2D and volumetric CT-image tests were compared. Results: Estimated reliabilities (Cronbach's alphas) were higher for volumetric CT-image scores (version A: .51 and version B: .54), than for 2D CT-image scores (version A: .24 and version B: .37). Participants found volumetric CT-image tests more representative of clinical practice, and considered them to be less difficult than volumetric CT-image questions. However, in one version (A), volumetric CT-image scores (M 80.9, SD 14.8) were significantly lower than 2D CT-image scores (M 88.4, SD 10.4) (p < .001). The volumetric CT-image testing program was considered user-friendly. Conclusion: This study shows that volumetric image questions can be successfully integrated in students’ radiology testing. Results suggests that the inclusion of volumetric CT-images might improve the quality of radiology tests by positively impacting perceived representativeness for clinical practice and increasing reliability of the test.

Multi-photon vertical cross-sectional imaging with a dynamically-balanced thin-film PZT z-axis microactuator.

Science.gov (United States)

Choi, Jongsoo; Duan, Xiyu; Li, Haijun; Wang, Thomas D; Oldham, Kenn R

2017-10-01

Use of a thin-film piezoelectric microactuator for axial scanning during multi-photon vertical cross-sectional imaging is described. The actuator uses thin-film lead-zirconate-titanate (PZT) to generate upward displacement of a central mirror platform, micro-machined from a silicon-on-insulator (SOI) wafer to dimensions compatible with endoscopic imaging instruments. Device modeling in this paper focuses on existence of frequencies near device resonance producing vertical motion with minimal off-axis tilt even in the presence of multiple vibration modes and non-uniformity in fabrication outcomes. Operation near rear resonance permits large stroke lengths at low voltages relative to other vertical microactuators. Highly uniform vertical motion of the mirror platform is a key requirement for vertical cross-sectional imaging in the remote scan architecture being used for multi-photon instrument prototyping. The stage is installed in a benchtop testbed in combination with an electrostatic mirror that performs in-plane scanning. Vertical sectional images are acquired from 15 μm diameter beads and excised mouse colon tissue.

Multislice CT imaging of pulmonary embolism

International Nuclear Information System (INIS)

Schoepf, J.U.; Kessler, M.A.; Rieger, C.T.; Herzog, P.; Wiesgigl, S.; Becker, C.R.; Exarhos, D.N.; Reiser, M.F.

2001-01-01

In recent years CT has been established as the method of choice for the diagnosis of central pulmonary embolism (PE) to the level of the segmental arteries. The key advantage of CT over competing modalities is the reliable detection of relevant alternative or additional disease causing the patient's symptoms. Although the clinical relevance of isolated peripheral emboli remains unclear, the alleged poor sensitivity of CT for the detection of such small clots has to date prevented the acceptance of CT as the gold standard for diagnosing PE. With the advent of multislice CT we can now cover the entire chest of a patient with 1-mm slices within one breath-hold. In comparison with thicker sections, the detection rate of subsegmental emboli can be significantly increased with 1-mm slices. In addition, the interobserver correlation which can be achieved with 1-mm sections by far exceeds the reproducibility of competing modalities. Meanwhile use of multislice CT for a combined diagnosis of PE and deep venous thrombosis with the same modality appears to be clinically accepted. In the vast majority of patients who receive a combined thoracic and venous multislice CT examination the scan either confirms the suspected diagnosis or reveals relevant alternative or additional disease. The therapeutic regimen is usually chosen based on the functional effect of embolic vascular occlusion. With the advent of fast CT scanning techniques, also functional parameters of lung perfusion can be non-invasively assessed by CT imaging. These advantages let multislice CT appear as an attractive modality for a non-invasive, fast, accurate, and comprehensive diagnosis of PE, its causes, effects, and differential diagnoses. (orig.)

Spatial variation of the section sensitivity profile in helical CT

International Nuclear Information System (INIS)

Katsuta, Shoichi; Hanai, Kouzou; Kunii, Takeo; Kimura, Haruki; Imabayashi, Wataru; Muramatsu, Yoshihisa

1999-01-01

The section sensitivity profile (SSP) is adequate to express the properties of helical CT images. Although SSP measurement has been performed only at the center of the imaging field, we applied it to off-center positions using a metal bead and controlled tracking technique. The experimental results indicated that SSP curves vary in the imaging field according to the relative position of the x-ray focus. The results were in agreement with computer simulations. (author)

Optimal reconstructed section thickness for the detection of liver lesions with multidetector CT

International Nuclear Information System (INIS)

Soo, G.; Lau, K.K.; Yik, T.; Kutschera, P.

2010-01-01

Aim: To evaluate the impact of different reconstructed section thicknesses on liver lesion detection using multidetector computed tomography (CT). Methods: Fifty-three patients were examined using a 16-section CT machine with axial reconstructions provided at 2.5, 5, 7.5, and 10 mm section thicknesses. Images of different reconstructed section thicknesses from different patients were presented in random order to three independent, blinded radiologists for review at multiple sessions. All images were then reviewed by three radiologists in a common session. Consensus was reached following review of the previous interpretation results and results of follow-up imaging regarding the number of true liver lesions (n = 101) for comparison. Results: Mean detection rates were as follows: 93/101 lesions detected with the 2.5 mm section thickness, 98/101 lesions detected at the 5 mm section thickness, 78/101 lesions detected at the 7.5 mm section thickness, and 54/101 lesions detected at the 10 mm section thickness. Lesions missed at the 2.5 mm section thickness were due to masking by image noise. There was particular difficulty detecting subcapsular lesions and lesions adjacent to fissures or the gall bladder at the 7.5 mm and 10 mm section thicknesses. Conclusion: The optimal reconstructed section thickness for lesion detection in the liver was 5 mm.

Prevalence of ligamentum arteriosum calcification on multi-section spiral CT and digital radiography.

Science.gov (United States)

Hong, Gil-Sun; Goo, Hyun Woo; Song, Jae-Woo

2012-06-01

To investigate the prevalence of ligamentum arteriosum calcification (LAC) on multi-section spiral CT and digital radiography. Five hundred and eight children and 232 adults who performed multi-section chest CT were included in this study and were divided into nine age groups: A (0-5 years), B (6-10 years), C (11-15 years), D (16-20 years), E (21-30 years), F (31-40 years), G (41-50 years), H (51-60 years), and I (61-70 years). Two radiologists assessed the presence of LAC on axial and coronal CT images, defined as focal calcific density on both or on one plane with attenuation >100 Hounsfield unit. The prevalence of LAC on CT was compared between children and adults, and between unenhanced and enhanced CT in children. The prevalence of LAC on digital radiography was evaluated in 476 children. The prevalence of definite LAC on unenhanced multi-section CT was significantly higher in children (37.8 %) than in adults (11.2 %) (P CT were 4.5, 12.8, 8.1, 19.0, 0.0, 0.0, 0.0, 2.0, and 1.9 %. In children, the prevalence of LAC was significantly higher on unenhanced than on enhanced CT (37.8 vs. 16.4 %, P children. LAC is frequently observed in children and adults on multi-section spiral CT, more frequently than previously reported. Compared with that on multi-section spiral CT, the prevalence of LAC on digital radiography is substantially low.

Integrating imaging FTIR and secondary ion mass spectrometry for the analysis of embedded paint cross-sections

DEFF Research Database (Denmark)

Heeren, Ron M.A.; Boon, Jaap J.; Noble, Petria

1999-01-01

Novel chemical imaging techniques provide new insight in the organic chemistry of embedded paint cross-sections. FTIR imaging microscopy delivers a two-dimensional image of the functional group distribution, revealing chemical aspects of the binding medium in each individual paint layer. Secondar...... and identity of various lead soaps and lead hydroxychloride in these inclusions....

Appropriate use of medical imaging in two Spanish public hospitals: a cross-sectional analysis

Science.gov (United States)

Vilar-Palop, Jorge; Hernandez-Aguado, Ildefonso; Pastor-Valero, María; Vilar, José; González-Alvarez, Isabel; Lumbreras, Blanca

2018-01-01

Objectives To determine the appropriateness of medical imaging examinations involving radiation and to estimate the effective radiation dose and costs associated. Design Cross-sectional retrospective study. Setting Two Spanish public tertiary hospitals. Participants 2022 medical imaging tests were extracted from the radiology information system in February and March of 2014. MRI and ultrasound examinations were excluded. Primary and secondary outcome measures Five outcomes were set independently by at least two researchers according to four guidelines: (1) appropriate; (2) inappropriate; (3) inappropriate due to repetition, if the timing to carry out next diagnostic tests was incorrect according to guidelines; (4) not adequately justified, if the referral form did not include enough clinical information to allow us to understand the patient’s clinical condition; and (5) not included in the guidelines, if the referral could not be matched to a clinical scenario described in the guidelines. We estimated the prevalence of the five categories according to relevant clinical and sociodemographic variables and the effective radiation dose and costs for each category. Results Approximately half of the imaging tests were deemed as appropriate (967, 47.8%) while one-third (634, 31.4%) were considered inappropriate. 19.6% of the effective dose and 25.2% of the cost were associated with inappropriate tests. Women were less likely than men to have an imaging test classified as appropriate (adjusted OR 0.70,95% CI 0.57 to 0.86). Imaging tests requested by general practitioners were less likely to be considered appropriate than those requested by central services (adjusted OR 0.60, 95% CI 0.38 to 0.93). Mammography and CT were more likely to be appropriate than conventional X-rays. Conclusion There was a significant frequency of inappropriateness, which resulted in a high percentage of associated effective radiation dose. Percentage of inappropriateness depends on

Appropriate use of medical imaging in two Spanish public hospitals: a cross-sectional analysis.

Science.gov (United States)

Vilar-Palop, Jorge; Hernandez-Aguado, Ildefonso; Pastor-Valero, María; Vilar, José; González-Alvarez, Isabel; Lumbreras, Blanca

2018-03-16

To determine the appropriateness of medical imaging examinations involving radiation and to estimate the effective radiation dose and costs associated. Cross-sectional retrospective study. Two Spanish public tertiary hospitals. 2022 medical imaging tests were extracted from the radiology information system in February and March of 2014. MRI and ultrasound examinations were excluded. Five outcomes were set independently by at least two researchers according to four guidelines: (1) appropriate; (2) inappropriate; (3) inappropriate due to repetition, if the timing to carry out next diagnostic tests was incorrect according to guidelines; (4) not adequately justified, if the referral form did not include enough clinical information to allow us to understand the patient's clinical condition; and (5) not included in the guidelines, if the referral could not be matched to a clinical scenario described in the guidelines. We estimated the prevalence of the five categories according to relevant clinical and sociodemographic variables and the effective radiation dose and costs for each category. Approximately half of the imaging tests were deemed as appropriate (967, 47.8%) while one-third (634, 31.4%) were considered inappropriate. 19.6% of the effective dose and 25.2% of the cost were associated with inappropriate tests. Women were less likely than men to have an imaging test classified as appropriate (adjusted OR 0.70,95% CI 0.57 to 0.86). Imaging tests requested by general practitioners were less likely to be considered appropriate than those requested by central services (adjusted OR 0.60, 95% CI 0.38 to 0.93). Mammography and CT were more likely to be appropriate than conventional X-rays. There was a significant frequency of inappropriateness, which resulted in a high percentage of associated effective radiation dose. Percentage of inappropriateness depends on sociodemographic and clinical characteristics such as sex, age, referral physician and medical imaging test

Highly sensitive detection of the soft tissues based on refraction contrast by in-plane diffraction-enhanced imaging CT

International Nuclear Information System (INIS)

Yuasa, Tetsuya; Hashimoto, Eiko; Maksimenko, Anton; Sugiyama, Hiroshi; Arai, Yoshinori; Shimao, Daisuke; Ichihara, Shu; Ando, Masami

2008-01-01

We discuss the recently proposed computed tomography (CT) technique based on refractive effects for biomedical use, which reconstructs the in-plane refractive-index gradient vector field in a cross-sectional plane of interest by detecting the angular deviation of the beam, refracted by a sample, from the incident beam, using the diffraction-enhanced imaging (DEI) method. The CT has advantages for delineating biological weakly absorbing soft tissues over the conventional absorption-contrast CT because of the use of phase sensitive detection. The paper aims to define the imaging scheme rigidly and to demonstrate its efficacy for non-destructive measurement of biomedical soft-tissue samples without imaging agent. We first describe the imaging principle of in-plane DEI-CT from the physico-mathematical viewpoints in detail, and investigate what physical quantities are extracted from the reconstructed images. Then, we introduce the imaging system using the synchrotron radiation as a light source, constructed at beamline BL-14B in KEK, Japan. Finally, we demonstrate the advantage of the refraction-based image for non-destructive analysis of biological sample by investigating the image of human breast cancer tumors obtained using the imaging system. Here, the refraction- and the apparent absorption-based images obtained simultaneously by the in-plane DEI-CT are compared. Also, the conventional absorption-based image obtained using micro-computed tomography (μCT) imaging system is compared with them. Thereby, it is shown that the refraction contrast much more sensitively delineates the soft tissues than the absorption contrast. In addition, the radiologic-histologic correlation study not only validates the efficacy for imaging soft tissues, but also produces the potential that the pathological inspection for the breast cancer tumors may be feasible non-destructively

New developments in imaging: Sonography, cine-CT, MRI

International Nuclear Information System (INIS)

Otto, R.J.; Higgins, C.B.

1987-01-01

The book can be conveniently subdivided into three sections: the first on magnetic resonance imaging the second on cine-computed tomography and the third on advances in ultrasound (US). The MR imaging section includes two chapters: the first on indications for MR in abdominal disease (a cookbook layout of indications for MR imaging versus CT) and the second on MR imaging of the heart. There are also chapters on MR imaging and US in the pelvis, contrast agent principles, and a chapter on imaging renal tumors. The third section, on US, contains chapters on the liver and gastrointenstinal disease, interventional US sonography during neurosurgery, state-of-the-art echocardiography. Doppler flow imaging, contrast media for sonography, endometrial sonography, and high-resolution US in the first trimester. The final chapter is presented as a scientific paper rather than as a chapter in a book and has no illustrations

CT and MR imaging of craniopharyngioma

Energy Technology Data Exchange (ETDEWEB)

Tsuda, M. [Tohoku Univ. School of Medicine, Sendai (Japan). Dept. of Radiology; Takahashi, S. [Tohoku Univ. School of Medicine, Sendai (Japan). Dept. of Radiology; Higano, S. [Tohoku Univ. School of Medicine, Sendai (Japan). Dept. of Radiology; Kurihara, N. [Tohoku Univ. School of Medicine, Sendai (Japan). Dept. of Radiology; Ikeda, H. [Tohoku Univ. School of Medicine, Sendai (Japan). Dept. of Neurosurgery; Sakamoto, K. [Tohoku Univ. School of Medicine, Sendai (Japan). Dept. of Radiology

1997-05-01

We reviewed imaging findings of CT and MR imaging in 20 cases of surgically confirmed craniopharyngioma in an attempt to determine their relation to patterns of tumor extent. The relationship between these patterns and the frequency of preoperative CT diagnosis and MR imaging diagnosis according to the surgical diagnosis were determined. The CT technique was superior to MR imaging in the detection of calcification. The MR imaging technique was superior to CT for determining tumor extent and provided valuable information about the relationships of the tumor to surrounding structures. Thus, CT and MR imaging have complementary roles in the diagnosis of craniopharyngiomas. In cases of possible craniopharyngioma, noncontrast sagittal T1-weighted images may enable the identification of the normal pituitary, possibly leading to the correct diagnosis. (orig.)

CT and MR imaging of craniopharyngioma

International Nuclear Information System (INIS)

Tsuda, M.; Takahashi, S.; Higano, S.; Kurihara, N.; Ikeda, H.; Sakamoto, K.

1997-01-01

We reviewed imaging findings of CT and MR imaging in 20 cases of surgically confirmed craniopharyngioma in an attempt to determine their relation to patterns of tumor extent. The relationship between these patterns and the frequency of preoperative CT diagnosis and MR imaging diagnosis according to the surgical diagnosis were determined. The CT technique was superior to MR imaging in the detection of calcification. The MR imaging technique was superior to CT for determining tumor extent and provided valuable information about the relationships of the tumor to surrounding structures. Thus, CT and MR imaging have complementary roles in the diagnosis of craniopharyngiomas. In cases of possible craniopharyngioma, noncontrast sagittal T1-weighted images may enable the identification of the normal pituitary, possibly leading to the correct diagnosis. (orig.)

Active voltage contrast imaging of cross-sectional surface of multilayer ceramic capacitor using helium ion microscopy

Energy Technology Data Exchange (ETDEWEB)

Sakai, C., E-mail: SAKAI.Chikako@nims.go.jp; Ishida, N.; Masuda, H.; Nagano, S.; Kitahara, M.; Fujita, D. [National Institute for Materials Science, Tsukuba, Ibaraki 305-0047 (Japan); Ogata, Y. [TAIYO YUDEN CO., LTD., Takasaki-shi, Gunma 370-3347 (Japan)

2016-08-01

We studied active voltage contrast (AVC) imaging using helium ion microscopy (HIM). We observed secondary electron (SE) images of the cross-sectional surface of multilayer ceramic capacitors (MLCCs) with and without a voltage applied to the internal electrodes. When no voltage was applied, we obtained an image reflecting the material contrast between the Ni internal electrode region and the BaTiO{sub 3} dielectric region of the cross-sectional surface of the MLCC. When a voltage was applied, the electrical potential difference between the grounded and the positively biased internal electrodes affected the contrast (voltage contrast). Moreover, attenuation of the SE intensity from the grounded to the positively biased internal electrodes was observed in the dielectric region. Kelvin probe force microscopy (KPFM) measurements of the contact potential difference (CPD) were performed on the same sample. By using the AVC image from the HIM observation and the CPD image from the KPFM measurement, we could quantitatively evaluate the electrical potential. We think that the results of this study will lead to an expansion in the number of applications of HIM.

Quantitative imaging of excised osteoarthritic cartilage using spectral CT

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Rajendran, Kishore; Bateman, Christopher J.; Younis, Raja Aamir; De Ruiter, Niels J.A.; Ramyar, Mohsen; Anderson, Nigel G. [University of Otago - Christchurch, Department of Radiology, Christchurch (New Zealand); Loebker, Caroline [University of Otago, Christchurch Regenerative Medicine and Tissue Engineering Group, Department of Orthopaedic Surgery and Musculoskeletal Medicine, Christchurch (New Zealand); University of Twente, Department of Developmental BioEngineering, Enschede (Netherlands); Schon, Benjamin S.; Hooper, Gary J.; Woodfield, Tim B.F. [University of Otago, Christchurch Regenerative Medicine and Tissue Engineering Group, Department of Orthopaedic Surgery and Musculoskeletal Medicine, Christchurch (New Zealand); Chernoglazov, Alex I. [University of Canterbury, Human Interface Technology Laboratory New Zealand, Christchurch (New Zealand); Butler, Anthony P.H. [University of Otago - Christchurch, Department of Radiology, Christchurch (New Zealand); European Organisation for Nuclear Research (CERN), Geneva (Switzerland); MARS Bioimaging, Christchurch (New Zealand)

2017-01-15

To quantify iodine uptake in articular cartilage as a marker of glycosaminoglycan (GAG) content using multi-energy spectral CT. We incubated a 25-mm strip of excised osteoarthritic human tibial plateau in 50 % ionic iodine contrast and imaged it using a small-animal spectral scanner with a cadmium telluride photon-processing detector to quantify the iodine through the thickness of the articular cartilage. We imaged both spectroscopic phantoms and osteoarthritic tibial plateau samples. The iodine distribution as an inverse marker of GAG content was presented in the form of 2D and 3D images after applying a basis material decomposition technique to separate iodine in cartilage from bone. We compared this result with a histological section stained for GAG. The iodine in cartilage could be distinguished from subchondral bone and quantified using multi-energy CT. The articular cartilage showed variation in iodine concentration throughout its thickness which appeared to be inversely related to GAG distribution observed in histological sections. Multi-energy CT can quantify ionic iodine contrast (as a marker of GAG content) within articular cartilage and distinguish it from bone by exploiting the energy-specific attenuation profiles of the associated materials. (orig.)

Diagnostic performance of 64-section CT using CT gastrography in preoperative T staging of gastric cancer according to 7th edition of AJCC cancer staging manual

International Nuclear Information System (INIS)

Kim, Jin Woong; Shin, Sang Soo; Heo, Suk Hee; Lim, Hyo Soon; Jeong, Yong Yeon; Kang, Heoung Keun; Choi, Yoo Duk; Park, Young Kyu; Park, Chang Hwan

2012-01-01

To evaluate the accuracy of 64-section multidetector CT with CT gastrography for determining the depth of mural invasion in patients with gastric cancer according to the 7th edition of the AJCC cancer staging manual. A total of 127 patients with gastric cancer and who had undergone both esophago-gastro-duodenoscopy and 64-section CT were included in this study. Two radiologists independently reviewed the preoperative CT images with respect to the detectability and T-staging of the gastric cancers. The sensitivity, specificity, accuracy and overall accuracy of each reviewer for the T staging of gastric cancer were calculated. Overall, gastric cancer was detected in 123 (96.9%) of the 127 cancers on the CT images. Reviewer 1 correctly staged 98 gastric cancers, and reviewer 2 correctly classified 105 gastric cancers. The overall diagnostic accuracy of the T staging was 77.2% (98/127) for reviewer 1 and 82.7% (105/127) for reviewer 2. 64-section CT using CT gastrography showed a reasonable diagnostic performance for determining the T staging in patients with gastric cancer according to the 7th edition of the AJCC cancer staging manual. (orig.)

CT false-profile view of the hip: a reproducible method of measuring anterior acetabular coverage using volume CT data

International Nuclear Information System (INIS)

Needell, Steven D.; Borzykowski, Ross M.; Carreira, Dominic S.; Kozy, John

2014-01-01

To devise a simple, reproducible method of using CT data to measure anterior acetabular coverage that results in values analogous to metrics derived from false-profile radiographs. Volume CT images were used to generate simulated false-profile radiographs and cross-sectional false-profile views by angling a multiplanar reformat 115 through the affected acetabulum relative to a line tangential to the posterior margin of the ischial tuberosities. The anterolateral margin of the acetabulum was localized on the CT false-profile view corresponding with the cranial opening of the acetabular roof. Anterior center edge angle (CEA) was measured between a vertical line passing through the center of the femoral head and a line connecting the center of the femoral head with the anterior edge of the condensed line of the acetabulum (sourcil). Anterior CEA values measured on CT false-profile views of 38 symptomatic hips were compared with values obtained on simulated and projection false-profile radiographs. The CT false-profile view produces a cross-sectional image in the same obliquity as false-profile radiographs. Anterior CEA measured on CT false-profile views were statistically similar to values obtained with false-profile radiographs. CT technologists quickly mastered the technique of generating this view. Inter-rater reliability indicated this method to be highly reproducible. The CT false-profile view is simple to generate and anterior CEA measurements derived from it are similar to those obtained using well-positioned false-profile radiographs. Utilization of CT to assess hip geometry enables precise control of pelvic inclination, eliminates projectional errors, and minimizes limitations of image quality inherent to radiography. (orig.)

CT false-profile view of the hip: a reproducible method of measuring anterior acetabular coverage using volume CT data

Energy Technology Data Exchange (ETDEWEB)

Needell, Steven D.; Borzykowski, Ross M. [Boca Radiology Group, Boca Raton, FL (United States); Carreira, Dominic S.; Kozy, John [Broward Health Orthopedics and Sports Medicine, Fort Lauderdale, FL (United States)

2014-11-15

To devise a simple, reproducible method of using CT data to measure anterior acetabular coverage that results in values analogous to metrics derived from false-profile radiographs. Volume CT images were used to generate simulated false-profile radiographs and cross-sectional false-profile views by angling a multiplanar reformat 115 through the affected acetabulum relative to a line tangential to the posterior margin of the ischial tuberosities. The anterolateral margin of the acetabulum was localized on the CT false-profile view corresponding with the cranial opening of the acetabular roof. Anterior center edge angle (CEA) was measured between a vertical line passing through the center of the femoral head and a line connecting the center of the femoral head with the anterior edge of the condensed line of the acetabulum (sourcil). Anterior CEA values measured on CT false-profile views of 38 symptomatic hips were compared with values obtained on simulated and projection false-profile radiographs. The CT false-profile view produces a cross-sectional image in the same obliquity as false-profile radiographs. Anterior CEA measured on CT false-profile views were statistically similar to values obtained with false-profile radiographs. CT technologists quickly mastered the technique of generating this view. Inter-rater reliability indicated this method to be highly reproducible. The CT false-profile view is simple to generate and anterior CEA measurements derived from it are similar to those obtained using well-positioned false-profile radiographs. Utilization of CT to assess hip geometry enables precise control of pelvic inclination, eliminates projectional errors, and minimizes limitations of image quality inherent to radiography. (orig.)

Automated Cross-Sectional Measurement Method of Intracranial Dural Venous Sinuses.

Science.gov (United States)

Lublinsky, S; Friedman, A; Kesler, A; Zur, D; Anconina, R; Shelef, I

2016-03-01

MRV is an important blood vessel imaging and diagnostic tool for the evaluation of stenosis, occlusions, or aneurysms. However, an accurate image-processing tool for vessel comparison is unavailable. The purpose of this study was to develop and test an automated technique for vessel cross-sectional analysis. An algorithm for vessel cross-sectional analysis was developed that included 7 main steps: 1) image registration, 2) masking, 3) segmentation, 4) skeletonization, 5) cross-sectional planes, 6) clustering, and 7) cross-sectional analysis. Phantom models were used to validate the technique. The method was also tested on a control subject and a patient with idiopathic intracranial hypertension (4 large sinuses tested: right and left transverse sinuses, superior sagittal sinus, and straight sinus). The cross-sectional area and shape measurements were evaluated before and after lumbar puncture in patients with idiopathic intracranial hypertension. The vessel-analysis algorithm had a high degree of stability with <3% of cross-sections manually corrected. All investigated principal cranial blood sinuses had a significant cross-sectional area increase after lumbar puncture (P ≤ .05). The average triangularity of the transverse sinuses was increased, and the mean circularity of the sinuses was decreased by 6% ± 12% after lumbar puncture. Comparison of phantom and real data showed that all computed errors were <1 voxel unit, which confirmed that the method provided a very accurate solution. In this article, we present a novel automated imaging method for cross-sectional vessels analysis. The method can provide an efficient quantitative detection of abnormalities in the dural sinuses. © 2016 by American Journal of Neuroradiology.

US-CT 3D dual imaging by mutual display of the same sections for depicting minor changes in hepatocellular carcinoma

Energy Technology Data Exchange (ETDEWEB)

Fukuda, Hiroyuki, E-mail: fukuhiro1962@hotmail.com [International HIFU Center, Sanmu Medical Center Hospital, Naruto 167, Sanbu-shi, Chiba 289-1326 (Japan); Ito, Ryu; Ohto, Masao; Sakamoto, Akio [International HIFU Center, Sanmu Medical Center Hospital, Naruto 167, Sanbu-shi, Chiba 289-1326 (Japan); Otsuka, Masayuki; Togawa, Akira; Miyazaki, Masaru [Department of General Surgery, Graduate School of Medicine, Chiba University, Inohana 1-8-1, Chuo-ku, Chiba-shi, Chiba 260-0856 (Japan); Yamagata, Hitoshi [Toshiba Medical Systems Corporation, Otawara 324-0036 (Japan)

2012-09-15

The purpose of this study was to evaluate the usefulness of ultrasound-computed tomography (US-CT) 3D dual imaging for the detection of small extranodular growths of hepatocellular carcinoma (HCC). The clinical and pathological profiles of 10 patients with single nodular type HCC with extranodular growth (extranodular growth) who underwent a hepatectomy were evaluated using two-dimensional (2D) ultrasonography (US), three-dimensional (3D) US, 3D computed tomography (CT) and 3D US-CT dual images. Raw 3D data was converted to DICOM (Digital Imaging and Communication in Medicine) data using Echo to CT (Toshiba Medical Systems Corp., Tokyo, Japan), and the 3D DICOM data was directly transferred to the image analysis system (ZioM900, ZIOSOFT Inc., Tokyo, Japan). By inputting the angle number (x, y, z) of the 3D CT volume data into the ZioM900, multiplanar reconstruction (MPR) images of the 3D CT data were displayed in a manner such that they resembled the conventional US images. Eleven extranodular growths were detected pathologically in 10 cases. 2D US was capable of depicting only 2 of the 11 extranodular growths. 3D CT was capable of depicting 4 of the 11 extranodular growths. On the other hand, 3D US was capable of depicting 10 of the 11 extranodular growths, and 3D US-CT dual images, which enable the dual analysis of the CT and US planes, revealed all 11 extranodular growths. In conclusion, US-CT 3D dual imaging may be useful for the detection of small extranodular growths.

US-CT 3D dual imaging by mutual display of the same sections for depicting minor changes in hepatocellular carcinoma

International Nuclear Information System (INIS)

Fukuda, Hiroyuki; Ito, Ryu; Ohto, Masao; Sakamoto, Akio; Otsuka, Masayuki; Togawa, Akira; Miyazaki, Masaru; Yamagata, Hitoshi

2012-01-01

The purpose of this study was to evaluate the usefulness of ultrasound-computed tomography (US-CT) 3D dual imaging for the detection of small extranodular growths of hepatocellular carcinoma (HCC). The clinical and pathological profiles of 10 patients with single nodular type HCC with extranodular growth (extranodular growth) who underwent a hepatectomy were evaluated using two-dimensional (2D) ultrasonography (US), three-dimensional (3D) US, 3D computed tomography (CT) and 3D US-CT dual images. Raw 3D data was converted to DICOM (Digital Imaging and Communication in Medicine) data using Echo to CT (Toshiba Medical Systems Corp., Tokyo, Japan), and the 3D DICOM data was directly transferred to the image analysis system (ZioM900, ZIOSOFT Inc., Tokyo, Japan). By inputting the angle number (x, y, z) of the 3D CT volume data into the ZioM900, multiplanar reconstruction (MPR) images of the 3D CT data were displayed in a manner such that they resembled the conventional US images. Eleven extranodular growths were detected pathologically in 10 cases. 2D US was capable of depicting only 2 of the 11 extranodular growths. 3D CT was capable of depicting 4 of the 11 extranodular growths. On the other hand, 3D US was capable of depicting 10 of the 11 extranodular growths, and 3D US-CT dual images, which enable the dual analysis of the CT and US planes, revealed all 11 extranodular growths. In conclusion, US-CT 3D dual imaging may be useful for the detection of small extranodular growths

Reconstruction of MRI/CT compatible ring and tandem applicators in CT or MRI images used for treatment planning in brachytherapy

International Nuclear Information System (INIS)

Surendran, N.; Kim, Hayeon; Beriwal, Sushil; Saiful Huq, M.

2008-01-01

Brachytherapy (BT) plays a crucial role in the management of invasive cervix cancer from stage I to IV. Intracavitary techniques are based on afterloading devices, with different types of applicators. CT and/or MRI compatible applicators allow a sectional image based approach with a better assessment of gross tumour volume (GTV) and definition and delineation of target volume (CTV) compared to traditional approaches. To evaluate reconstruction of MRI/CT compatible ring and tandem applicators in 3D CT or MRI images used for treatment planning in Brachytherapy

Detecting airway remodeling in COPD and emphysema using low-dose CT imaging

Science.gov (United States)

Rudyanto, R.; Ceresa, M.; Muñoz-Barrutia, A.; Ortiz-de-Solorzano, C.

2012-03-01

In this study, we quantitatively characterize lung airway remodeling caused by smoking-related emphysema and Chronic Obstructive Pulmonary Disease (COPD), in low-dose CT scans. To that end, we established three groups of individuals: subjects with COPD (n=35), subjects with emphysema (n=38) and healthy smokers (n=28). All individuals underwent a low-dose CT scan, and the images were analyzed as described next. First the lung airways were segmented using a fast marching method and labeled according to its generation. Along each airway segment, cross-section images were resampled orthogonal to the airway axis. Next 128 rays were cast from the center of the airway lumen in each crosssection slice. Finally, we used an integral-based method, to measure lumen radius, wall thickness, mean wall percentage and mean peak wall attenuation on every cast ray. Our analysis shows that both the mean global wall thickness and the lumen radius of the airways of both COPD and emphysema groups were significantly different from those of the healthy group. In addition, the wall thickness change starts at the 3rd airway generation in the COPD patients compared with emphysema patients, who display the first significant changes starting in the 2nd generation. In conclusion, it is shown that airway remodeling happens in individuals suffering from either COPD or emphysema, with some local difference between both groups, and that we are able to detect and accurately quantify this process using images of low-dose CT scans.

Radiation therapy treatment planning: CT, MR imaging and three-dimensional planning

International Nuclear Information System (INIS)

Lichter, A.S.

1987-01-01

The accuracy and sophistication of radiation therapy treatment planning have increased rapidly in the last decade. Currently, CT-based treatment planning is standard throughout the country. Care must be taken when CT is used for treatment planning because of clear differences between diagnostic scans and scans intended for therapeutic management. The use of CT in radiation therapy planning is discussed and illustrated. MR imaging adds another dimension to treatment planning. The ability to use MR imaging directly in treatment planning involves an additional complex set of capabilities from a treatment planning system. The ability to unwarp the geometrically distorted MR image is a first step. Three-dimensional dose calculations are important to display the dose on sagittal and acoronal sections. The ability to integrate the MR and CT images into a unified radiographic image is critical. CT and MR images are two-dimensional representations of a three-dimensional problem. Through sophisticated computer graphics techniques, radiation therapists are now able to integrate a three-dimensional image of the patient into the treatment planning process. This allows the use of noncoplanar treatment plans and a detailed analysis of tumor and normal tissue anatomy; it is the first step toward a fully conformational treatment planning system. These concepts are illustrated and future research goals outlined

Development and practice for a PACS-based interactive teaching model for CT image

International Nuclear Information System (INIS)

Tian Junzhang; Jiang Guihua; Zheng Liyin; Wang Ling; Wenhua; Liang Lianbao

2002-01-01

Objective: To explore the interactive teaching model for CT imaging based on PACS, and provide the clinician and young radiologist with continued medical education. Methods: 100 M trunk net was adopted in PACS and 10 M was exchanged on desktop. Teaching model was installed in browse and diagnosis workstation. Teaching contents were classified according to region and managed according to branch model. Text data derived from authoritative textbooks, monograph, and periodicals. Imaging data derived from cases proved by pathology and clinic. The data were obtained through digital camera and scanner or from PACS. After edited and transformed into standard digital image through DICOM server, they were saved in HD of PACS image server with file form. Results: Teaching model for CT imaging provided kinds of cases of CT sign, clinic characteristics, pathology and distinguishing diagnosis. Normal section anatomy, typical image, and its notation could be browsed real time. Teaching model for CT imaging could provide reference to teaching, diagnosis and report. Conclusion: PACS-based teaching model for CT imaging could provide interactive teaching and scientific research tool and improve work quality and efficiency

Assessment of tumor heterogeneity by CT texture analysis: Can the largest cross-sectional area be used as an alternative to whole tumor analysis?

International Nuclear Information System (INIS)

Ng, Francesca; Kozarski, Robert; Ganeshan, Balaji; Goh, Vicky

2013-01-01

Objective: To determine if there is a difference between contrast enhanced CT texture features from the largest cross-sectional area versus the whole tumor, and its effect on clinical outcome prediction. Methods: Entropy (E) and uniformity (U) were derived for different filter values (1.0–2.5: fine to coarse textures) for the largest primary tumor cross-sectional area and the whole tumor of the staging contrast enhanced CT in 55 patients with primary colorectal cancer. Parameters were compared using non-parametric Wilcoxon test. Kaplan–Meier analysis was performed to determine the relationship between CT texture and 5-year overall survival. Results: E was higher and U lower for the whole tumor indicating greater heterogeneity at all filter levels (1.0–2.5): median (range) for E and U for whole tumor versus largest cross-sectional area of 7.89 (7.43–8.31) versus 7.62 (6.94–8.08) and 0.005 (0.004–0.01) versus 0.006 (0.005–0.01) for filter 1.0; 7.88 (7.22–8.48) versus 7.54 (6.86–8.1) and 0.005 (0.003–0.01) versus 0.007 (0.004–0.01) for filter 1.5; 7.88 (7.17–8.54) versus 7.48 (5.84–8.25) and 0.005 (0.003–0.01) versus 0.007 (0.004–0.02) for filter 2.0; and 7.83 (7.03–8.57) versus 7.42 (5.19–8.26) and 0.005 (0.003–0.01) versus 0.006 (0.004–0.03) for filter 2.5 respectively (p ≤ 0.001). Kaplan–Meier analysis demonstrated better separation of E and U for whole tumor analysis for 5-year overall survival. Conclusion: Whole tumor analysis appears more representative of tumor heterogeneity

Optimization of SPECT-CT Hybrid Imaging Using Iterative Image Reconstruction for Low-Dose CT: A Phantom Study.

Directory of Open Access Journals (Sweden)

Oliver S Grosser

Full Text Available Hybrid imaging combines nuclear medicine imaging such as single photon emission computed tomography (SPECT or positron emission tomography (PET with computed tomography (CT. Through this hybrid design, scanned patients accumulate radiation exposure from both applications. Imaging modalities have been the subject of long-term optimization efforts, focusing on diagnostic applications. It was the aim of this study to investigate the influence of an iterative CT image reconstruction algorithm (ASIR on the image quality of the low-dose CT images.Examinations were performed with a SPECT-CT scanner with standardized CT and SPECT-phantom geometries and CT protocols with systematically reduced X-ray tube currents. Analyses included image quality with respect to photon flux. Results were compared to the standard FBP reconstructed images. The general impact of the CT-based attenuation maps used during SPECT reconstruction was examined for two SPECT phantoms. Using ASIR for image reconstructions, image noise was reduced compared to FBP reconstructions for the same X-ray tube current. The Hounsfield unit (HU values reconstructed by ASIR were correlated to the FBP HU values(R2 ≥ 0.88 and the contrast-to-noise ratio (CNR was improved by ASIR. However, for a phantom with increased attenuation, the HU values shifted for low X-ray tube currents I ≤ 60 mA (p ≤ 0.04. In addition, the shift of the HU values was observed within the attenuation corrected SPECT images for very low X-ray tube currents (I ≤ 20 mA, p ≤ 0.001.In general, the decrease in X-ray tube current up to 30 mA in combination with ASIR led to a reduction of CT-related radiation exposure without a significant decrease in image quality.

Associations of Age, BMI, and Years of Menstruation with Proximal Femur Strength in Chinese Postmenopausal Women: A Cross-Sectional Study.

Science.gov (United States)

Kang, Huili; Chen, Yu-Ming; Han, Guiyuan; Huang, Hua; Chen, Wei-Qing; Wang, Xidan; Zhu, Ying-Ying; Xiao, Su-Mei

2016-01-23

This study aimed to elucidate the associations of age, BMI, and years of menstruation with proximal femur strength in Chinese postmenopausal women, which may improve the prediction of hip fracture risk. A cross-sectional study was conducted in 1322 Chinese postmenopausal women recruited from communities. DXA images were used to generate bone mineral density (BMD) and geometric parameters, including cross-sectional area (CSA), outer diameter (OD), cortical thickness (CT), section modulus (SM), buckling ratio (BR) at the narrow neck (NN), intertrochanter (IT), and femoral shaft (FS). Relationships of age, BMI, and years of menstruation with bone phenotypes were analyzed with the adjustment of height, age at menarche, total daily physical activity, education, smoking status, calcium tablet intake, etc. Age was associated with lower BMD, CSA, CT, SM, and higher BR (p menstruation had the positive relationships with proximal femur strength (p menstruation were 0.14%-1.34%, 0.20%-2.70%, and 0.16%-0.98%, respectively. These results supported that bone strength deteriorated with aging and enhanced with higher BMI and longer time of years of menstruation in Chinese postmenopausal women.

Cross-sectional imaging with rotational panoramic X-ray machine for preoperative assessment of dental implant site. Comparisons of imaging properties with conventional film tomography and computed tomography

International Nuclear Information System (INIS)

Makihara, Masahiro; Nishikawa, Keiichi; Kuroyanagi, Kinya

2001-01-01

To clarify the validity of cross-sectional imaging with rotational panoramic x-ray machine for preoperative assessment of the dental implant site, the imaging properties were compared with those of spiral tomography and multi-planer reconstruction (MPR) manipulation of x-ray computed tomography. Cross-sectional imaging of the maxilla and mandible of an edentulous dry skull was performed by each technique at an image layer thickness of 1 mm. Steel spheres were used to identify cross-sectional planes and measure distance. Six oral radiologists scored the image clarity of structures with 5-grade rating scales and measured the distance between images of 2 steel spheres. Each measured distance was divided by the magnification factor. The actual distance was also measured on the skull. The score and the distance were statistically compared. The Spearman's rank correlation coefficients for the score and the absolute values of the difference in distances measured by different observers were calculated as test units to compare inter-observer agreements statistically. The same observation and measurement were repeated to compare intra-observer agreement. Image clarity of the linear tomography available with a panoramic machine was comparable to spiral tomography and superior to MPR, except for the cortical bone on the lingual side. The inter- and intra-observer agreements were comparable. The accuracy for measurement of distance, the inter- and intra-observer agreements were also comparable to the spiral tomography and superior to those of MPR. Therefore, it is concluded that cross-sectional imaging with a rotational panoramic x-ray machine is useful for preoperative assessment of the dental implant site. (author)

NMR-CT image and symbol phantoms

International Nuclear Information System (INIS)

Hongo, Syozo; Yamaguchi, Hiroshi; Takeshita, Hiroshi

1990-01-01

We have developed Japanese phantoms in two procedures. One is described as a mathematical expression. Another is 'symbol phantoms' in 3 dimensional picture-elements, each of which symbolize an organ name. The concept and the algorithm of the symbol phantom enables us to make a phantom for a individual in terms of all his transversal section images. We got 85 transversal section images of head and trunk parts, and those of 40 legs parts by using NMR-CT. We have made the individual phantom for computation of organ doses. The transversal section images were not so clear to identify all organs needed to dose estimation that we had to do hand-editing the shapes of organs with viewing a typical section images: we could not yet make symbol phantom in a automatic editing. Symbols were coded to be visual cords as ASCII characters. After we got the symbol phantom of the first stage, we can edit it easily using a word-processor. Symbol phantom could describe more freely the shape of organs than mathematical phantom. Symbol phantom has several advantages to be an individual phantom, but the only difficult point is how to determine its end-point as a reference man when we apply the method to build the reference man. (author)

Evaluation of living renal donors: accuracy of three-dimensional 16-section CT

Energy Technology Data Exchange (ETDEWEB)

Rastogi, N; Sahani, D.V.; Blake, M.A.; Ko, D.C.; Mueller, P.R. [Massachusetts General Hospital, Boston, MA (United States). Dept. of Radiology

2006-07-15

Purpose: To retrospectively assess the sensitivity and specificity of three-dimensional (3D) 16-section computed tomography (CT) in the evaluation of vessels, pelvicalyceal system, and ureters in living renal donors, with surgical findings as the reference standard. Materials and methods: This was a HIPAA-compliant study. Institutional review board approval was obtained for the review of subjects' medical records and data analysis, with waiver of informed consent. Forty-six renal donors (18 men, 28 women; mean age, 42 years) were examined with 16-section CT. Two blinded reviewers independently studied renal vascular and urographic anatomy of each donor CT scans by fist using 3D images alone, then transverse images alone, and finally transverse and 3D data set. Image quality, degree of diagnostic confidence, and time used for review were recorded. Sensitivity and specificity were calculated. Results: For 3D images, transverse images, and transverse in conjunction with 3D data sets, the respective sensitivity and specificity of CT in evaluation of accessory arteries by reviewer 1 were 100% and 100%, 89% and 100%, and 100% and 100%, and those by reviewer 2 were 89% and 97%, 89% and 100%, and 89% and 100%; the respective sensitivity and specificity in evaluation of venous anomalies by reviewer 1 were 100% and 98%, 100% and 98%, and 100% and 98%, and those by reviewer 2 were 100% and 98%, 100% and 95%, and 100% and 98%. For focused comprehensive assessment of renal donors with 3D scans alone, a reviewer on average (average of reviewers 1 and 2) used 2.4 minutes per scan, demonstrated full confidence in 93%, and rated the quality as excellent in 76%. Conclusion: For focused assessment of renal vascular and urographic anatomy, review of 3D data set alone provides high sensitivity and specificity with regard to findings seen at surgery. (author)

Evaluation of living renal donors: accuracy of three-dimensional 16-section CT

International Nuclear Information System (INIS)

Rastogi, N; Sahani, D.V.; Blake, M.A.; Ko, D.C.; Mueller, P.R.

2006-01-01

Purpose: To retrospectively assess the sensitivity and specificity of three-dimensional (3D) 16-section computed tomography (CT) in the evaluation of vessels, pelvicalyceal system, and ureters in living renal donors, with surgical findings as the reference standard. Materials and methods: This was a HIPAA-compliant study. Institutional review board approval was obtained for the review of subjects' medical records and data analysis, with waiver of informed consent. Forty-six renal donors (18 men, 28 women; mean age, 42 years) were examined with 16-section CT. Two blinded reviewers independently studied renal vascular and urographic anatomy of each donor CT scans by fist using 3D images alone, then transverse images alone, and finally transverse and 3D data set. Image quality, degree of diagnostic confidence, and time used for review were recorded. Sensitivity and specificity were calculated. Results: For 3D images, transverse images, and transverse in conjunction with 3D data sets, the respective sensitivity and specificity of CT in evaluation of accessory arteries by reviewer 1 were 100% and 100%, 89% and 100%, and 100% and 100%, and those by reviewer 2 were 89% and 97%, 89% and 100%, and 89% and 100%; the respective sensitivity and specificity in evaluation of venous anomalies by reviewer 1 were 100% and 98%, 100% and 98%, and 100% and 98%, and those by reviewer 2 were 100% and 98%, 100% and 95%, and 100% and 98%. For focused comprehensive assessment of renal donors with 3D scans alone, a reviewer on average (average of reviewers 1 and 2) used 2.4 minutes per scan, demonstrated full confidence in 93%, and rated the quality as excellent in 76%. Conclusion: For focused assessment of renal vascular and urographic anatomy, review of 3D data set alone provides high sensitivity and specificity with regard to findings seen at surgery. (author)

Implications of CT noise and artifacts for quantitative 99mTc SPECT/CT imaging

International Nuclear Information System (INIS)

Hulme, K. W.; Kappadath, S. C.

2014-01-01

Purpose: This paper evaluates the effects of computed tomography (CT) image noise and artifacts on quantitative single-photon emission computed-tomography (SPECT) imaging, with the aim of establishing an appropriate range of CT acquisition parameters for low-dose protocols with respect to accurate SPECT attenuation correction (AC). Methods: SPECT images of two geometric and one anthropomorphic phantom were reconstructed iteratively using CT scans acquired at a range of dose levels (CTDI vol = 0.4 to 46 mGy). Resultant SPECT image quality was evaluated by comparing mean signal, background noise, and artifacts to SPECT images reconstructed using the highest dose CT for AC. Noise injection was performed on linear-attenuation (μ) maps to determine the CT noise threshold for accurate AC. Results: High levels of CT noise (σ ∼ 200–400 HU) resulted in low μ-maps noise (σ ∼ 1%–3%). Noise levels greater than ∼10% in 140 keV μ-maps were required to produce visibly perceptible increases of ∼15% in 99m Tc SPECT images. These noise levels would be achieved at low CT dose levels (CTDI vol = 4 μGy) that are over 2 orders of magnitude lower than the minimum dose for diagnostic CT scanners. CT noise could also lower (bias) the expected μ values. The relative error in reconstructed SPECT signal trended linearly with the relative shift in μ. SPECT signal was, on average, underestimated in regions corresponding with beam-hardening artifacts in CT images. Any process that has the potential to change the CT number of a region by ∼100 HU (e.g., misregistration between CT images and SPECT images due to motion, the presence of contrast in CT images) could introduce errors in μ 140 keV on the order of 10%, that in turn, could introduce errors on the order of ∼10% into the reconstructed 99m Tc SPECT image. Conclusions: The impact of CT noise on SPECT noise was demonstrated to be negligible for clinically achievable CT parameters. Because CT dose levels that affect

Obscure gastrointestinal bleeding: preliminary comparison of 64-section CT enteroclysis with video capsule endoscopy

International Nuclear Information System (INIS)

Khalife, Samer; Vahedi, Kouroche; Dray, Xavier; Marteau, Philippe; Soyer, Philippe; Hamzi, Lounis; Place, Vinciane; Boudiaf, Mourad; Alatawi, Abdullah

2011-01-01

To retrospectively compare the diagnostic capabilities of 64-section CT enteroclysis with those of video capsule endoscopy (VCE) to elucidate the cause of obscure gastrointestinal bleeding. Thirty-two patients who had 64-section CT enteroclysis and VCE because of obscure gastrointestinal bleeding were included. Imaging findings were compared with those obtained at double balloon endoscopy, surgery and histopathological analysis, which were used as a standard of reference. Concordant findings were found in 22 patients (22/32; 69%), including normal findings (n = 13), tumours (n = 7), lymphangiectasia (n = 1) and inflammation (n = 1), and discrepancies in 10 patients (10/32; 31%), including ulcers (n = 3), angioectasias (n = 2), tumours (n = 2) and normal findings (n = 3). No statistical difference in the proportions of abnormal findings between 64-section CT enteroclysis (11/32; 34%) and VCE (17/32, 53%) (P = 0.207) was found. However, 64-section CT enteroclysis helped identify tumours not detected at VCE (n = 2) and definitely excluded suspected tumours (n = 3) because of bulges at VCE. Conversely, VCE showed ulcers (n = 3) and angioectasias (n = 2) which were not visible at 64-section CT enteroclysis. Our results suggest that 64-section CT enteroclysis and VCE have similar overall diagnostic yields in patients with obscure gastrointestinal bleeding. However, the two techniques are complementary in this specific population. (orig.)

Radiation exposure in whole body CT screening.

Science.gov (United States)

Suresh, Pamidighantam; Ratnam, S V; Rao, K V J

2011-04-01

Using a technology that "takes a look" at people's insides and promises early warnings of cancer, cardiac disease, and other abnormalities, clinics and medical imaging facilities nationwide are touting a new service for health conscious people: "Whole body CT screening" this typically involves scanning the body from the chin to below the hips with a form of x-ray imaging that produces cross-sectional images. In USA direct-to-consumer marketing of whole body CT is occurring today in many metropolitan areas. Free standing CT screening centres are being sited in shopping malls and other high density public areas, and these centres are being advertised in the electronic and print media. In this context the present article discussed the pros and cons of having such centres in India with the advent of multislice CT leading to fast scan times.

SPECT/CT workflow and imaging protocols

Energy Technology Data Exchange (ETDEWEB)

Beckers, Catherine [University Hospital of Liege, Division of Nuclear Medicine and Oncological Imaging, Department of Medical Physics, Liege (Belgium); Hustinx, Roland [University Hospital of Liege, Division of Nuclear Medicine and Oncological Imaging, Department of Medical Physics, Liege (Belgium); Domaine Universitaire du Sart Tilman, Service de Medecine Nucleaire et Imagerie Oncologique, CHU de Liege, Liege (Belgium)

2014-05-15

Introducing a hybrid imaging method such as single photon emission computed tomography (SPECT)/CT greatly alters the routine in the nuclear medicine department. It requires designing new workflow processes and the revision of original scheduling process and imaging protocols. In addition, the imaging protocol should be adapted for each individual patient, so that performing CT is fully justified and the CT procedure is fully tailored to address the clinical issue. Such refinements often occur before the procedure is started but may be required at some intermediate stage of the procedure. Furthermore, SPECT/CT leads in many instances to a new partnership with the radiology department. This article presents practical advice and highlights the key clinical elements which need to be considered to help understand the workflow process of SPECT/CT and optimise imaging protocols. The workflow process using SPECT/CT is complex in particular because of its bimodal character, the large spectrum of stakeholders, the multiplicity of their activities at various time points and the need for real-time decision-making. With help from analytical tools developed for quality assessment, the workflow process using SPECT/CT may be separated into related, but independent steps, each with its specific human and material resources to use as inputs or outputs. This helps identify factors that could contribute to failure in routine clinical practice. At each step of the process, practical aspects to optimise imaging procedure and protocols are developed. A decision-making algorithm for justifying each CT indication as well as the appropriateness of each CT protocol is the cornerstone of routine clinical practice using SPECT/CT. In conclusion, implementing hybrid SPECT/CT imaging requires new ways of working. It is highly rewarding from a clinical perspective, but it also proves to be a daily challenge in terms of management. (orig.)

SPECT/CT workflow and imaging protocols

International Nuclear Information System (INIS)

Beckers, Catherine; Hustinx, Roland

2014-01-01

Introducing a hybrid imaging method such as single photon emission computed tomography (SPECT)/CT greatly alters the routine in the nuclear medicine department. It requires designing new workflow processes and the revision of original scheduling process and imaging protocols. In addition, the imaging protocol should be adapted for each individual patient, so that performing CT is fully justified and the CT procedure is fully tailored to address the clinical issue. Such refinements often occur before the procedure is started but may be required at some intermediate stage of the procedure. Furthermore, SPECT/CT leads in many instances to a new partnership with the radiology department. This article presents practical advice and highlights the key clinical elements which need to be considered to help understand the workflow process of SPECT/CT and optimise imaging protocols. The workflow process using SPECT/CT is complex in particular because of its bimodal character, the large spectrum of stakeholders, the multiplicity of their activities at various time points and the need for real-time decision-making. With help from analytical tools developed for quality assessment, the workflow process using SPECT/CT may be separated into related, but independent steps, each with its specific human and material resources to use as inputs or outputs. This helps identify factors that could contribute to failure in routine clinical practice. At each step of the process, practical aspects to optimise imaging procedure and protocols are developed. A decision-making algorithm for justifying each CT indication as well as the appropriateness of each CT protocol is the cornerstone of routine clinical practice using SPECT/CT. In conclusion, implementing hybrid SPECT/CT imaging requires new ways of working. It is highly rewarding from a clinical perspective, but it also proves to be a daily challenge in terms of management. (orig.)

CT and MR imaging of the liver. Clinical importance of nutritional status

International Nuclear Information System (INIS)

Leander, P.; Sjoeberg, S.; Hoeglund, P.

2000-01-01

Purpose: In an experimental study in rats a correlation between nutritional status and hepatic attenuation in CT and signal intensities in MR imaging was shown. Is physiological nutritional status of importance in clinical CT and MR imaging? Material and methods: In a cross-over study including 12 healthy volunteers (6 women and 6 men, mean age 34 years), CT and MR imaging of the liver were performed with nutritional status at three different levels, i.e., normal, fasting and after glycogen-rich meals. CT and MR were performed on clinical imaging systems and hepatic attenuation and signal intensity, respectively, were assessed. In MR, T1-weighted, proton density-weighted and T2-weighted pulse-sequences were used. Results: In CT there were significantly (p<0.01) higher liver attenuations in normal nutritional status and after glycogen rich-meals compared to the fasting condition. The difference between fasting and glycogen-rich meals were 10.5 HU for men, 7.4 for women and mean 8.8 HU for all 12 volunteers. In MR imaging the differences were small and non-significant. The results of this study are in accordance with an earlier experimental study in rats. Conclusion: In CT it may be of importance not to have patients in a fasting condition as it lowers the attenuation in normal liver tissue. The findings are important for planning of clinical studies where hepatic attenuation will be assessed and may be of some importance in clinical CT. In MR imaging the results indicate that the nutritional status is of less importance

How to interpret an unenhanced CT Brain scan. Part 1: Basic principles of Computed Tomography and relevant neuroanatomy

Directory of Open Access Journals (Sweden)

Thomas Osborne

2016-08-01

Full Text Available The aim of this article is to: Cover the basics of Computed Tomography (CT Brain imaging. Review relevant CT neuroanatomy. A CT image is produced by firing x-rays at a moving object which is then detected by an array of rotating detectors (Figure 1. The detected x-rays are then converted into a computerised signal which is used to produce a series of cross sectional images.

Imaging of patent foramen ovale with 64-section multidetector CT.

Science.gov (United States)

Saremi, Farhood; Channual, Stephanie; Raney, Aidan; Gurudevan, Swaminatha V; Narula, Jagat; Fowler, Steven; Abolhoda, Amir; Milliken, Jeffrey C

2008-11-01

To investigate the feasibility of 64-section multidetector computed tomography (CT) by using CT angiography (a) to demonstrate anatomic detail of the interatrial septum pertinent to the patent foramen ovale (PFO), and (b) to visually detect left-to-right PFO shunts and compare these findings in patients who also underwent transesophageal echocardiography (TEE). In this institutional review board-approved HIPAA-compliant study, electrocardiographically gated coronary CT angiograms in 264 patients (159 men, 105 women; mean age, 60 years) were reviewed for PFO morphologic features. The length and diameter of the opening of the PFO tunnel, presence of atrial septal aneurysm (ASA), and PFO shunts were evaluated. A left-to-right shunt was assigned a grade according to length of contrast agent jet (grade 1, 1 cm to 2 cm; grade 3, >2 cm). In addition, 23 patients who underwent both modalities were compared (Student t test and linear regression analysis). A difference with P patent at the entry into the right atrium (PFO) in 62 patients (61.4% of patients with flap valve, 23.5% of total patients). A left-to-right shunt was detected in 44 (16.7% of total) patients (grade 1, 61.4%; grade 2, 34.1%; grade 3, 4.5%). No shunt was seen in patients without a flap valve. Mean length of PFO tunnel was 7.1 mm in 44 patients with a shunt and 12.1 mm in 57 patients with a flap valve without a shunt (P < .0001). In patients with a tunnel length of 6 mm or shorter, 92.6% of the shunts were seen. ASA was seen in 11 (4.2%) patients; of these patients, a shunt was seen in seven (63.6%). In 23 patients who underwent CT angiography and TEE, both modalities showed a PFO shunt in seven. Multidetector CT provides detailed anatomic information about size, morphologic features, and shunt grade of the PFO. Shorter tunnel length and septal aneurysms are frequently associated with left-to-right shunts in patients with PFO. (c) RSNA, 2008.

C-arm CT for planning and guidance of extrahepatic embolizations

International Nuclear Information System (INIS)

Wacker, F.K.; Meissner, O.A.; Meyer, B.C.

2009-01-01

Interventional radiological vascular embolizations are complex procedures that require exact imaging of the target region to facilitate safe and effective treatment. The purpose of this paper is to present the technique and feasibility of flat detector C-arm computed tomography (C-arm CT) for control and guidance of extrahepatic abdominal embolization procedures. C-arm CT images can provide important information on both vascular and cross-sectional anatomy of the target region, help in determining therapy endpoints and provide follow-up during and immediately after the abdominal interventions.The cases presented demonstrate that C-arm CT images are beneficial for abdominal embolization procedures and facilitate precise treatment. (orig.) [de

Clinical PET/CT imaging. Promises and misconceptions

International Nuclear Information System (INIS)

Czernin, J.; Auerbach, M.A.

2005-01-01

PET/CT is now established as the most important imaging tool in oncology. PET/CT stages and restages cancer with a higher accuracy than PET or CT alone. The sometimes irrational approach to combine state of the art PET with the highest end CT devices should give way to a more reasonable equipment design tailored towards the specific clinical indications in well-defined patient populations. The continuing success of molecular PET/CT now depends more upon advances in molecular imaging with the introduction of targeted imaging probes for individualized therapy approaches in cancer patients and less upon technological advances of imaging equipment. (orig.)

Manchester medical society (imaging section) presidential address 2008

Energy Technology Data Exchange (ETDEWEB)

Blakeley, C. [University of Salford (United Kingdom); Manchester Royal Infirmary (CMFT) (United Kingdom)], E-mail: c.blakeley@salford.ac.uk; Hogg, P. [University of Salford (United Kingdom)

2009-12-15

This article is based partly upon the Presidential Address of the Manchester Medical Society (Imaging Section) in 2008. It reviews the development of radiology services in the Manchester (UK) area from their inception in 1896 to the installation of the first EMI body CT scanner in Europe. It considers some of the innovative people in the Manchester area and some milestone events that occurred in that area to help establish the role and value of X-ray in diagnostic imaging. In this article the first recorded case of when X-ray imaging was used in a forensic domiciliary case is also outlined; this occurred approximately 35 miles north of Manchester on 23rd April 1896. The article also explains some interesting background information on the development of the first EMI CT scanner, drawing particularly on the revenue stream generated by the music section of EMI through the success of The Beatles - a band which emanated 35 miles from Manchester in Liverpool.

Manchester medical society (imaging section) presidential address 2008

International Nuclear Information System (INIS)

Blakeley, C.; Hogg, P.

2009-01-01

This article is based partly upon the Presidential Address of the Manchester Medical Society (Imaging Section) in 2008. It reviews the development of radiology services in the Manchester (UK) area from their inception in 1896 to the installation of the first EMI body CT scanner in Europe. It considers some of the innovative people in the Manchester area and some milestone events that occurred in that area to help establish the role and value of X-ray in diagnostic imaging. In this article the first recorded case of when X-ray imaging was used in a forensic domiciliary case is also outlined; this occurred approximately 35 miles north of Manchester on 23rd April 1896. The article also explains some interesting background information on the development of the first EMI CT scanner, drawing particularly on the revenue stream generated by the music section of EMI through the success of The Beatles - a band which emanated 35 miles from Manchester in Liverpool.

Cone Beam CT vs. Fan Beam CT: A Comparison of Image Quality and Dose Delivered Between Two Differing CT Imaging Modalities.

Science.gov (United States)

Lechuga, Lawrence; Weidlich, Georg A

2016-09-12

A comparison of image quality and dose delivered between two differing computed tomography (CT) imaging modalities-fan beam and cone beam-was performed. A literature review of quantitative analyses for various image quality aspects such as uniformity, signal-to-noise ratio, artifact presence, spatial resolution, modulation transfer function (MTF), and low contrast resolution was generated. With these aspects quantified, cone beam computed tomography (CBCT) shows a superior spatial resolution to that of fan beam, while fan beam shows a greater ability to produce clear and anatomically correct images with better soft tissue differentiation. The results indicate that fan beam CT produces superior images to that of on-board imaging (OBI) cone beam CT systems, while providing a considerably less dose to the patient.

Pericardial sinuses and recesses effusion of 16-slice helical CT imaging and anatomic correlation

International Nuclear Information System (INIS)

Lu Chunyan; Yang Zhigang; Zhou Xiangping; Yu Jianqun; Zhu Jie; Yang Kaiqing

2007-01-01

Objective: To evaluate the CT features and implications of the pericardial sinuses and recesses effusion by combining the sectional cadavers and 16 multi-slice CT (MSCT) reformation. Methods: The anatomy and communication of the pericardial sinuses and recesses on the axial, coronal and saggital sectional cadavers (respectively 1 case), and the morphologic features on MSCT reformatted images in 104 patients were observed. The detection rate of effusion was analyzed. Results: The sectional cadavers and CT images showed that the pericardial sinuses and recesses were formed by the reflections of the pericardium on the root of the great vessels. The detection rate of the sinuses and recesses was lower in small effusion than in moderate and large effusion (P<0.05). The superior aortic recess was the most common recess for pericardial effusion. Conclusion: The MSCT reformatted images can show the morphologic features of pericardial sinuses and recesses effusion and communications with the pericardial cavity, help differentiate pericardial effusion from other mediastinal or pericardial lesions. (authors)

Three-dimensional reconstruction of CT images

Energy Technology Data Exchange (ETDEWEB)

Watanabe, Toshiaki; Kattoh, Keiichi; Kawakami, Genichiroh; Igami, Isao; Mariya, Yasushi; Nakamura, Yasuhiko; Saitoh, Yohko; Tamura, Koreroku; Shinozaki, Tatsuyo

1986-09-01

Computed tomography (CT) has the ability to provide sensitive visualization of organs and lesions. Owing to the nature of CT to be transaxial images, a structure which is greater than a certain size appears as several serial CT images. Consequently each observer must reconstruct those images into a three-dimensional (3-D) form mentally. It has been supposed to be of great use if such a 3-D form can be described as a definite figure. A new computer program has been developed which can produce 3-D figures from the profiles of organs and lesions on CT images using spline curves. The figures obtained through this method are regarded to have practical applications.

CT guided stereotaxy based on scout view imaging

Energy Technology Data Exchange (ETDEWEB)

Wester, K; Kjartansson, O; Bakke, S J

1987-05-01

A simple and inexpensive method for CT guided sterotaxy is described. The method requires no extra equipment in the interface between the computer tomograph and the stereotaxic frame, and could therefore easily be adopted in most neurosurgical units. With this method, information from the transaxial CT sections is transferred manually via the scout view image to the operation theater skull X-rays, and thereby to the stereotaxic frame. The method has proved to be sufficiently accurate for all current non-functional stereotaxic procedures in our department during 30 months of testing.

CT guided stereotaxy based on scout view imaging

International Nuclear Information System (INIS)

Wester, K.; Kjartansson, O.; Bakke, S.J.; Rikshospitalet, Oslo

1987-01-01

A simple and inexpensive method for CT guided sterotaxy is described. The method requires no extra equipment in the interface between the computer tomograph and the stereotaxic frame, and could therefore easily be adopted in most neurosurgical units. With this method, information from the transaxial CT sections is transferred manually via the scout view image to the operation theater skull X-rays, and thereby to the stereotaxic frame. The method has proved to be sufficiently accurate for all current non-functional stereotaxic procedures in our department during 30 months of testing. (orig.)

Predicting the fidelity of JPEG2000 compressed CT images using DICOM header information

International Nuclear Information System (INIS)

Kim, Kil Joong; Kim, Bohyoung; Lee, Hyunna; Choi, Hosik; Jeon, Jong-June; Ahn, Jeong-Hwan; Lee, Kyoung Ho

2011-01-01

Purpose: To propose multiple logistic regression (MLR) and artificial neural network (ANN) models constructed using digital imaging and communications in medicine (DICOM) header information in predicting the fidelity of Joint Photographic Experts Group (JPEG) 2000 compressed abdomen computed tomography (CT) images. Methods: Our institutional review board approved this study and waived informed patient consent. Using a JPEG2000 algorithm, 360 abdomen CT images were compressed reversibly (n = 48, as negative control) or irreversibly (n = 312) to one of different compression ratios (CRs) ranging from 4:1 to 10:1. Five radiologists independently determined whether the original and compressed images were distinguishable or indistinguishable. The 312 irreversibly compressed images were divided randomly into training (n = 156) and testing (n = 156) sets. The MLR and ANN models were constructed regarding the DICOM header information as independent variables and the pooled radiologists' responses as dependent variable. As independent variables, we selected the CR (DICOM tag number: 0028, 2112), effective tube current-time product (0018, 9332), section thickness (0018, 0050), and field of view (0018, 0090) among the DICOM tags. Using the training set, an optimal subset of independent variables was determined by backward stepwise selection in a four-fold cross-validation scheme. The MLR and ANN models were constructed with the determined independent variables using the training set. The models were then evaluated on the testing set by using receiver-operating-characteristic (ROC) analysis regarding the radiologists' pooled responses as the reference standard and by measuring Spearman rank correlation between the model prediction and the number of radiologists who rated the two images as distinguishable. Results: The CR and section thickness were determined as the optimal independent variables. The areas under the ROC curve for the MLR and ANN predictions were 0.91 (95% CI; 0

The findings and the role of axial CT imaging and 3D imaging of gastric lesion by spiral CT

International Nuclear Information System (INIS)

Lee, Dong Ho; Ko, Young Tae

1996-01-01

The purpose of this study is to assess the efficacy of axial CT imaging and 3D imaging by spiral CT in the detection and evaluation of gastric lesion. Seventy-seven patients with pathologically-proven gastric lesions underwent axial CT and 3D imaging by spiral CT. There were 49 cases of advanced gastric carcinoma(AGC), 21 of early gastric carcinoma (EGC), three of benign ulcers, three of leiomyomas, and one case of lymphoma. Spiral CT was performed with 3-mm collimation, 4.5mm/sec table feed, and 1-1.5-mm reconstruction interval after the ingestion of gas. 3D imaging was obtained using the SSD technique, and on analysis a grade was given(excellent, good, poor). Axial CT scan was performed with 5-mm collimation, 7mm/sec table feed, and 5-mm reconstruction interval after the ingestion of water. Among 49 cases of AGC, excellent 3D images were obtained in seven patients (14.3%), good 3D images in 30(61.2%), and poor 3D images in 12(24.5%). Among the 12 patients with poor images, the cancers were located at the pyloric antrum in eight cases, were AGC Borrmann type 4 in three cases, and EGC-mimicking lesion in one case. Using axial CT scan alone, Borrmann's classification based tumor morphology were accurately identified in 67.3% of cases, but using 3D imaging, the corresponding figure was 85.7%. In 33 cases receiving surgery, good correlation between axial CT scan and pathology occurred in 72.7% of T class, and 69.7% of N class. Among 21 cases of EGC, excellent 3D images were obtained in three patients (14.3%), good 3D images in 14 (66.7%), and poor 3D images in two (9.5%). The other two cases of EGC were not detected. By axial CT scan, no tumor was detected in four cases, and there were two doubtful cases. 3D images of three benign ulcers were excellent in one case and good in two. 3D images of three leiomyomas and one lymphoma were excellent. Combined axial CT imaging and 3D imaging by spiral CT has the potential to accurately diagnose gastric lesions other than AGC

Algorithms of CT value correction for reconstructing a radiotherapy simulation image through axial CT images

International Nuclear Information System (INIS)

Ogino, Takashi; Egawa, Sunao

1991-01-01

New algorithms of CT value correction for reconstructing a radiotherapy simulation image through axial CT images were developed. One, designated plane weighting method, is to correct CT value in proportion to the position of the beam element passing through the voxel. The other, designated solid weighting method, is to correct CT value in proportion to the length of the beam element passing through the voxel and the volume of voxel. Phantom experiments showed fair spatial resolution in the transverse direction. In the longitudinal direction, however, spatial resolution of under slice thickness could not be obtained. Contrast resolution was equivalent for both methods. In patient studies, the reconstructed radiotherapy simulation image was almost similar in visual perception of the density resolution to a simulation film taken by X-ray simulator. (author)

Differential diagnosis of primary nasopharyngeal lymphoma and nasopharyngeal carcinoma focusing on CT, MRI, and PET/CT.

Science.gov (United States)

Cho, Kyu-Sup; Kang, Dae-Woon; Kim, Hak-Jin; Lee, Jong-Kil; Roh, Hwan-Jung

2012-04-01

No study has done a comparative analysis of radiologic imaging findings between primary nasopharyngeal lymphoma (PNL) and nasopharyngeal carcinoma (NPC). The purpose of this study was to analyze computed tomography (CT) and magnetic resonance (MR) images and to evaluate the maximum standardized uptake value (SUV max) of positron emission tomography (PET)/CT between PNL and NPC, knowing the imaging features that distinguish PNL from NPC. Cross-sectional study. University tertiary care facility. The authors analyzed the features on CT, MR imaging, and PET/CT of 16 patients diagnosed with PNL and 32 patients diagnosed with NPC histopathologically. Patients with PNL had a larger tumor volume and showed symmetry of tumor shape than did patients with NPC. Patients with PNL also had higher tumor homogeneity than NPC patients on CT, T2-weighted, and postcontrast MR images. All PNL patients showed a high degree of enhancement without invasion to the adjacent deep structure. The involvement of the Waldeyer ring was significantly higher in PNL patients. Cervical and retropharyngeal lymphadenopathy and PET/CT SUV max showed no significant difference between PNL and NPC. If the images present a bulky, symmetric nasopharyngeal mass with marked homogeneity, a high degree of enhancement, and a higher Waldeyer ring involvement combined with no invasion into the deep structure, PNL should be considered over NPC.

Targeted Molecular Imaging in Adrenal Disease—An Emerging Role for Metomidate PET-CT

Directory of Open Access Journals (Sweden)

Iosif A. Mendichovszky

2016-11-01

Full Text Available Adrenal lesions present a significant diagnostic burden for both radiologists and endocrinologists, especially with the increasing number of adrenal ‘incidentalomas’ detected on modern computed tomography (CT or magnetic resonance imaging (MRI. A key objective is the reliable distinction of benign disease from either primary adrenal malignancy (e.g., adrenocortical carcinoma or malignant forms of pheochromocytoma/paraganglioma (PPGL or metastases (e.g., bronchial, renal. Benign lesions may still be associated with adverse sequelae through autonomous hormone hypersecretion (e.g., primary aldosteronism, Cushing’s syndrome, phaeochromocytoma. Here, identifying a causative lesion, or lateralising the disease to a single adrenal gland, is key to effective management, as unilateral adrenalectomy may offer the potential for curing conditions that are typically associated with significant excess morbidity and mortality. This review considers the evolving role of positron emission tomography (PET imaging in addressing the limitations of traditional cross-sectional imaging and adjunctive techniques, such as venous sampling, in the management of adrenal disorders. We review the development of targeted molecular imaging to the adrenocortical enzymes CYP11B1 and CYP11B2 with different radiolabeled metomidate compounds. Particular consideration is given to iodo-metomidate PET tracers for the diagnosis and management of adrenocortical carcinoma, and the increasingly recognized utility of 11C-metomidate PET-CT in primary aldosteronism.

Do Foley Catheters Adequately Drain the Bladder? Evidence from CT Imaging Studies

Directory of Open Access Journals (Sweden)

Svetlana Avulova

2015-06-01

Full Text Available ABSTRACTIntroduction:The Foley catheter has been widely assumed to be an effective means of draining the bladder. However, recent studies have brought into question its efficacy. The objective of our study is to further assess the adequacy of Foley catheter for complete drainage of the bladder.Materials and Methods:Consecutive catheterized patients were identified from a retrospective review of contrast enhanced and non-contrast enhanced computed tomo-graphic (CT abdomen and pelvis studies completed from 7/1/2011-6/30/2012. Residual urine volume (RUV was measured using 5mm axial CT sections as follows: The length (L and width (W of the bladder in the section with the greatest cross sectional area was combined with bladder height (H as determined by multiplanar reformatted images in order to calculate RUV by applying the formula for the volume (V of a sphere in a cube: V=(ϖ/6*(L*W*H.Results:RUVs of 167 (mean age 67 consecutively catheterized men (n=72 and women (n=95 identified by CT abdomen and pelvis studies were calculated. The mean RUV was 13.2 mL (range: 0.0 mL-859.1 mL, standard deviation: 75.9 mL, margin of error at 95% confidence:11.6 mL. Four (2.4% catheterized patients had RUVs of >50 mL, two of whom had an improperly placed catheter tip noted on their CT-reports.Conclusions:Previous studies have shown that up to 43% of catheterized patients had a RUV greater than 50 mL, suggesting inadequacy of bladder drainage via the Foley catheter. Our study indicated that the vast majority of patients with Foley catheters (97.6%, had adequately drained bladders with volumes of

Do Foley catheters adequately drain the bladder? Evidence from CT imaging studies

Energy Technology Data Exchange (ETDEWEB)

Avulova, Svetlana; Li, Valery J.; Khusid, Johnathan A. [Department of Urology, SUNY Downstate College of Medicine, Brooklyn, NY (United States); Choi, Woo S. [Radiology, SUNY Downstate College of Medicine, Brooklyn, NY (United States); Weiss, Jeffrey P., E-mail: johnathan.khusid@downstate.edu [Department of Urology, Weill Cornell Medical College, New York, NY (United States)

2015-05-15

Introduction: The Foley catheter has been widely assumed to be an effective means of draining the bladder. However, recent studies have brought into question its efficacy. The objective of our study is to further assess the adequacy of Foley catheter for complete drainage of the bladder. Materials and Methods: Consecutive catheterized patients were identified from a retrospective review of contrast enhanced and non-contrast enhanced computed tomographic (CT) abdomen and pelvis studies completed from 7/1/2011-6/30/2012. Residual urine volume (RUV) was measured using 5mm axial CT sections as follows: The length (L) and width (W) of the bladder in the section with the greatest cross sectional area was combined with bladder height (H) as determined by multiplanar reformatted images in order to calculate RUV by applying the formula for the volume (V) of a sphere in a cube:V=(π/6)⁎L⁎W⁎H). Results: RUVs of 167 (mean age 67) consecutively catheterized men (n=72) and women (n=95) identified by CT abdomen and pelvis studies were calculated. The mean RUV was 13.2 mL (range: 0.0 mL-859.1 mL, standard deviation: 75.9 mL, margin of error at 95% confidence:11.6 mL). Four (2.4%) catheterized patients had RUVs of >50 mL, two of whom had an improperly placed catheter tip noted on their CT-reports. Conclusions: Previous studies have shown that up to 43% of catheterized patients had a RUV greater than 50 mL, suggesting inadequacy of bladder drainage via the Foley catheter. Our study indicated that the vast majority of patients with Foley catheters (97.6%), had adequately drained bladders with volumes of <50 mL. (author)

CT of the pelvis after cesarean section

International Nuclear Information System (INIS)

Twickler, D.; Setiawan, H.; Harrell, R.; Brown, C.E.L.

1989-01-01

Febrile morbidity following cesarean section is often evaluated with CT, although the CT appearance of the normal uterus has not been evaluated. This study was undertaken to learn the normal uterine appearance after cesarean section. To date, 15 women who also underwent bilateral tubal ligation have been studied. Six had a vertical uterine incision; nine had a low transverse incision. Contrast-enhanced pelvic CT was performed 1--5 days after surgery. All women were asymptomatic, with a normal postpartum course

CT in dental osseointegration

International Nuclear Information System (INIS)

Witte, D.

1992-01-01

Computerised tomography (CT) plays a key role in the pre-surgical evaluation of the alveolar process for titanium dental implants. The successful replacement of lost teeth by tissue integrated tooth root implants is a major advance in clinical dentistry. The paper will discuss briefly the history of osseointegration and how CT is now involved in helping the edentulous patient. CT is considered as a quick and convenient method of obtaining excellent anatomical information about the maxilla. Conventional tomography is difficult to obtain and does not provide valuable cross-sectional images. Exact height and width calculations can be made as well as screening out patients with advanced bone resorption. 3 refs. 6 figs

Applying microCT and 3D visualization to Jurassic silicified conifer seed cones: A virtual advantage over thin-sectioning.

Science.gov (United States)

Gee, Carole T

2013-11-01

As an alternative to conventional thin-sectioning, which destroys fossil material, high-resolution X-ray computed tomography (also called microtomography or microCT) integrated with scientific visualization, three-dimensional (3D) image segmentation, size analysis, and computer animation is explored as a nondestructive method of imaging the internal anatomy of 150-million-year-old conifer seed cones from the Late Jurassic Morrison Formation, USA, and of recent and other fossil cones. • MicroCT was carried out on cones using a General Electric phoenix v|tome|x s 240D, and resulting projections were processed with visualization software to produce image stacks of serial single sections for two-dimensional (2D) visualization, 3D segmented reconstructions with targeted structures in color, and computer animations. • If preserved in differing densities, microCT produced images of internal fossil tissues that showed important characters such as seed phyllotaxy or number of seeds per cone scale. Color segmentation of deeply embedded seeds highlighted the arrangement of seeds in spirals. MicroCT of recent cones was even more effective. • This is the first paper on microCT integrated with 3D segmentation and computer animation applied to silicified seed cones, which resulted in excellent 2D serial sections and segmented 3D reconstructions, revealing features requisite to cone identification and understanding of strobilus construction.

Integration of PET-CT and cone-beam CT for image-guided radiotherapy with high image quality and registration accuracy

Science.gov (United States)

Wu, T.-H.; Liang, C.-H.; Wu, J.-K.; Lien, C.-Y.; Yang, B.-H.; Huang, Y.-H.; Lee, J. J. S.

2009-07-01

Hybrid positron emission tomography-computed tomography (PET-CT) system enhances better differentiation of tissue uptake of 18F-fluorodeoxyglucose (18F-FDG) and provides much more diagnostic value in the non-small-cell lung cancer and nasopharyngeal carcinoma (NPC). In PET-CT, high quality CT images not only offer diagnostic value on anatomic delineation of the tissues but also shorten the acquisition time for attenuation correction (AC) compared with PET-alone imaging. The linear accelerators equipped with the X-ray cone-beam computed tomography (CBCT) imaging system for image-guided radiotherapy (IGRT) provides excellent verification on position setup error. The purposes of our study were to optimize the CT acquisition protocols of PET-CT and to integrate the PET-CT and CBCT for IGRT. The CT imaging parameters were modified in PET-CT for increasing the image quality in order to enhance the diagnostic value on tumour delineation. Reproducibility and registration accuracy via bone co-registration algorithm between the PET-CT and CBCT were evaluated by using a head phantom to simulate a head and neck treatment condition. Dose measurement in computed tomography dose index (CTDI) was also estimated. Optimization of the CT acquisition protocols of PET-CT was feasible in this study. Co-registration accuracy between CBCT and PET-CT on axial and helical modes was in the range of 1.06 to 2.08 and 0.99 to 2.05 mm, respectively. In our result, it revealed that the accuracy of the co-registration with CBCT on helical mode was more accurate than that on axial mode. Radiation doses in CTDI were 4.76 to 18.5 mGy and 4.83 to 18.79 mGy on axial and helical modes, respectively. Registration between PET-CT and CBCT is a state-of-the-art registration technology which could provide much information on diagnosis and accurate tumour contouring on radiotherapy while implementing radiotherapy procedures. This novelty technology of PET-CT and cone-beam CT integration for IGRT may have a

Integration of PET-CT and cone-beam CT for image-guided radiotherapy with high image quality and registration accuracy

International Nuclear Information System (INIS)

Wu, T-H; Liang, C-H; Wu, J-K; Lien, C-Y; Yang, B-H; Lee, J J S; Huang, Y-H

2009-01-01

Hybrid positron emission tomography-computed tomography (PET-CT) system enhances better differentiation of tissue uptake of 18 F-fluorodeoxyglucose ( 18 F-FDG) and provides much more diagnostic value in the non-small-cell lung cancer and nasopharyngeal carcinoma (NPC). In PET-CT, high quality CT images not only offer diagnostic value on anatomic delineation of the tissues but also shorten the acquisition time for attenuation correction (AC) compared with PET-alone imaging. The linear accelerators equipped with the X-ray cone-beam computed tomography (CBCT) imaging system for image-guided radiotherapy (IGRT) provides excellent verification on position setup error. The purposes of our study were to optimize the CT acquisition protocols of PET-CT and to integrate the PET-CT and CBCT for IGRT. The CT imaging parameters were modified in PET-CT for increasing the image quality in order to enhance the diagnostic value on tumour delineation. Reproducibility and registration accuracy via bone co-registration algorithm between the PET-CT and CBCT were evaluated by using a head phantom to simulate a head and neck treatment condition. Dose measurement in computed tomography dose index (CTDI) was also estimated. Optimization of the CT acquisition protocols of PET-CT was feasible in this study. Co-registration accuracy between CBCT and PET-CT on axial and helical modes was in the range of 1.06 to 2.08 and 0.99 to 2.05 mm, respectively. In our result, it revealed that the accuracy of the co-registration with CBCT on helical mode was more accurate than that on axial mode. Radiation doses in CTDI were 4.76 to 18.5 mGy and 4.83 to 18.79 mGy on axial and helical modes, respectively. Registration between PET-CT and CBCT is a state-of-the-art registration technology which could provide much information on diagnosis and accurate tumour contouring on radiotherapy while implementing radiotherapy procedures. This novelty technology of PET-CT and cone-beam CT integration for IGRT may have a

Clinical assessment of SPECT/CT co-registration image fusion

International Nuclear Information System (INIS)

Zhou Wen; Luan Zhaosheng; Peng Yong

2004-01-01

Objective: Study the methodology of the SPECT/CT co-registration image fusion, and Assessment the Clinical application value. Method: 172 patients who underwent SPECT/CT image fusion during 2001-2003 were studied, 119 men, 53 women. 51 patients underwent 18FDG image +CT, 26 patients underwent 99m Tc-RBC Liver pool image +CT, 43 patients underwent 99mTc-MDP Bone image +CT, 18 patients underwent 99m Tc-MAA Lung perfusion image +CT. The machine is Millium VG SPECT of GE Company. All patients have been taken three steps image: X-ray survey, X-ray transmission and nuclear emission image (Including planer imaging, SPECT or 18 F-FDG of dual head camera) without changing the position of the patients. We reconstruct the emission image with X-ray map and do reconstruction, 18FDG with COSEM and 99mTc with OSEM. Then combine the transmission image and the reconstructed emission image. We use different process parameters in deferent image methods. The accurate rate of SPECT/CT image fusion were statistics, and compare their accurate with that of single nuclear emission image. Results: The nuclear image which have been reconstructed by X-ray attenuation and OSEM are apparent better than pre-reconstructed. The post-reconstructed emission images have no scatter lines around the organs. The outline between different issues is more clear than before. The validity of All post-reconstructed images is better than pre-reconstructed. SPECT/CT image fusion make localization have worthy bases. 138 patients, the accuracy of SPECT/CT image fusion is 91.3% (126/138), whereas 60(88.2%) were found through SPECT/CT image fusion, There are significant difference between them(P 99m Tc- RBC-SPECT +CT image fusion, but 21 of them were inspected by emission image. In BONE 99m Tc -MDP-SPECT +CT image fusion, 4 patients' removed bone(1-6 months after surgery) and their relay with normal bone had activity, their morphologic and density in CT were different from normal bones. 11 of 20 patients who could

Improving image quality in portal venography with spectral CT imaging

International Nuclear Information System (INIS)

Zhao, Li-qin; He, Wen; Li, Jian-ying; Chen, Jiang-hong; Wang, Ke-yang; Tan, Li

2012-01-01

Objective: To investigate the effect of energy spectral CT on the image quality of CT portal venography in cirrhosis patients. Materials and methods: 30 portal hypertension patients underwent spectral CT examination using a single-tube, fast dual tube voltage switching technique. 101 sets of monochromatic images were generated from 40 keV to 140 keV. Image noise and contrast-to-noise ratio (CNR) for portal veins from the monochromatic images were measured. An optimal monochromatic image set was selected for obtaining the best CNR for portal veins. The image noise and CNR of the intra-hepatic portal vein and extra-hepatic main stem at the selected monochromatic level were compared with those from the conventional polychromatic images. Image quality was also assessed and compared. Results: The monochromatic images at 51 keV were found to provide the best CNR for both the intra-hepatic and extra-hepatic portal veins. At this energy level, the monochromatic images had about 100% higher CNR than the polychromatic images with a moderate 30% noise increase. The qualitative image quality assessment was also statistically higher with monochromatic images at 51 keV. Conclusion: Monochromatic images at 51 keV for CT portal venography could improve CNR for displaying hepatic portal veins and improve the overall image quality.

Improving image quality in portal venography with spectral CT imaging

Energy Technology Data Exchange (ETDEWEB)

Zhao, Li-qin, E-mail: zhaolqzr@sohu.com [Department of Radiology, Beijing Friendship Hospital Affiliated to Capital Medical University, Beijing,100050 (China); He, Wen, E-mail: hewen1724@sina.com [Department of Radiology, Beijing Friendship Hospital Affiliated to Capital Medical University, Beijing,100050 (China); Li, Jian-ying, E-mail: jianying.li@med.ge.com [CT Advanced Application and Research, GE Healthcare, 100176 China (China); Chen, Jiang-hong, E-mail: chenjianghong1973@hotmail.com [Department of Radiology, Beijing Friendship Hospital Affiliated to Capital Medical University, Beijing,100050 (China); Wang, Ke-yang, E-mail: ke7ke@sina.com [Department of Radiology, Beijing Friendship Hospital Affiliated to Capital Medical University, Beijing,100050 (China); Tan, Li, E-mail: Litan@ge.com [CT product, GE Healthcare, 100176 China (China)

2012-08-15

Objective: To investigate the effect of energy spectral CT on the image quality of CT portal venography in cirrhosis patients. Materials and methods: 30 portal hypertension patients underwent spectral CT examination using a single-tube, fast dual tube voltage switching technique. 101 sets of monochromatic images were generated from 40 keV to 140 keV. Image noise and contrast-to-noise ratio (CNR) for portal veins from the monochromatic images were measured. An optimal monochromatic image set was selected for obtaining the best CNR for portal veins. The image noise and CNR of the intra-hepatic portal vein and extra-hepatic main stem at the selected monochromatic level were compared with those from the conventional polychromatic images. Image quality was also assessed and compared. Results: The monochromatic images at 51 keV were found to provide the best CNR for both the intra-hepatic and extra-hepatic portal veins. At this energy level, the monochromatic images had about 100% higher CNR than the polychromatic images with a moderate 30% noise increase. The qualitative image quality assessment was also statistically higher with monochromatic images at 51 keV. Conclusion: Monochromatic images at 51 keV for CT portal venography could improve CNR for displaying hepatic portal veins and improve the overall image quality.

Quantitative analysis of length-diameter distribution and cross-sectional properties of fibers from three-dimensional tomographic images

DEFF Research Database (Denmark)

Miettinen, Arttu; Joffe, Roberts; Madsen, Bo

2013-01-01

obtained from optical microscopy of polished cross-sections of a composite. This approach gives accurate yet local results, but a rather large number of optical images have to be processed to achieve a representative description of the morphology of the material. In this work a fully automatic algorithm......A number of rule-of-mixture micromechanical models have been successfully used to predict the mechanical properties of short fiber composites. However, in order to obtain accurate predictions, a detailed description of the internal structure of the material is required. This information is often...... for estimating the length-diameter distribution of solid or hollow fibers, utilizing three-dimensional X-ray tomographic images, is presented. The method is based on a granulometric approach for fiber length distribution measurement, combined with a novel algorithm that relates cross-sectional fiber properties...

90Y microsphere therapy: does 90Y PET/CT imaging obviate the need for 90Y Bremsstrahlung SPECT/CT imaging?

Science.gov (United States)

Zade, Anand A; Rangarajan, Venkatesh; Purandare, Nilendu C; Shah, Sneha A; Agrawal, Archi R; Kulkarni, Suyash S; Shetty, Nitin

2013-11-01

Transarterial radioembolization using Y microspheres is a novel therapeutic option for inoperable hepatic malignancies. As these spheres are radiolucent, real-time assessment of their distribution during the infusion process under fluoroscopic guidance is not possible. Bremsstrahlung radiations arising from 90Y have conventionally been used for imaging its biodistribution. Recent studies have proved that sources of 90Y also emit positrons, which can further be used for PET/computed tomography (CT) imaging. This study aimed to assess the feasibility of 90Y PET/CT imaging in evaluating microsphere distributions and to compare its findings with those of Bremsstrahlung imaging. Thirty-five sessions of 90Y microsphere transarterial radioembolization were performed on 30 patients with hepatic malignancies. 90Y PET/CT imaging was performed within 3 h of therapy. Bremsstrahlung imaging was also performed for each patient. The imaging findings were compared for concordance in the distribution of microspheres. Exact one-to-one correspondence between 90Y PET/CT imaging and 90Y Bremsstrahlung imaging was observed in 97.14% of cases (i.e. in 34/35 cases). Discordance was observed only in one case in which 90Y PET/CT imaging resolved the microsphere uptake in the inferior vena cava tumor thrombus, which was, however, not visualized on Bremsstrahlung imaging. There is good concordance in the imaging findings of 90Y PET/CT and 90Y Bremsstrahlung imaging. 90Y PET/CT imaging scores over the conventionally used Bremsstrahlung imaging in terms of better resolution, ease of technique, and comparable image acquisition time. This makes it a preferred imaging modality for assessment of the distribution of 90Y microspheres.

Cortical region of interest definition on SPECT brain images using X-ray CT registration

Energy Technology Data Exchange (ETDEWEB)

Tzourio, N.; Sutton, D. (Commissariat a l' Energie Atomique, Orsay (France). Service Hospitalier Frederic Joliot); Joliot, M. (Commissariat a l' Energie Atomique, Orsay (France). Service Hospitalier Frederic Joliot INSERM, Orsay (France)); Mazoyer, B.M. (Commissariat a l' Energie Atomique, Orsay (France). Service Hospitalier Frederic Joliot Antenne d' Information Medicale, C.H.U. Bichat, Paris (France)); Charlot, V. (Hopital Louis Mourier, Colombes (France). Service de Psychiatrie); Salamon, G. (CHU La Timone, Marseille (France). Service de Neuroradiologie)

1992-11-01

We present a method for brain single photon emission computed tomography (SPECT) analysis based on individual registration of anatomical (CT) and functional ([sup 133]Xe regional cerebral blood flow) images and on the definition of three-dimensional functional regions of interest. Registration of CT and SPECT is performed through adjustment of CT-defined cortex limits to the SPECT image. Regions are defined by sectioning a cortical ribbon on the CT images, copied over the SPECT images and pooled through slices to give 3D cortical regions of interest. The proposed method shows good intra- and interobserver reproducibility (regional intraclass correlation coefficient [approx equal]0.98), and good accuracy in terms of repositioning ([approx equal]3.5 mm) as compared to the SPECT image resolution (14 mm). The method should be particularly useful for analysing SPECT studies when variations in brain anatomy (normal or abnormal) must be accounted for. (orig.).

Registration of 2D C-Arm and 3D CT Images for a C-Arm Image-Assisted Navigation System for Spinal Surgery

Directory of Open Access Journals (Sweden)

Chih-Ju Chang

2015-01-01

Full Text Available C-Arm image-assisted surgical navigation system has been broadly applied to spinal surgery. However, accurate path planning on the C-Arm AP-view image is difficult. This research studies 2D-3D image registration methods to obtain the optimum transformation matrix between C-Arm and CT image frames. Through the transformation matrix, the surgical path planned on preoperative CT images can be transformed and displayed on the C-Arm images for surgical guidance. The positions of surgical instruments will also be displayed on both CT and C-Arm in the real time. Five similarity measure methods of 2D-3D image registration including Normalized Cross-Correlation, Gradient Correlation, Pattern Intensity, Gradient Difference Correlation, and Mutual Information combined with three optimization methods including Powell’s method, Downhill simplex algorithm, and genetic algorithm are applied to evaluate their performance in converge range, efficiency, and accuracy. Experimental results show that the combination of Normalized Cross-Correlation measure method with Downhill simplex algorithm obtains maximum correlation and similarity in C-Arm and Digital Reconstructed Radiograph (DRR images. Spine saw bones are used in the experiment to evaluate 2D-3D image registration accuracy. The average error in displacement is 0.22 mm. The success rate is approximately 90% and average registration time takes 16 seconds.

PET/CT imaging in head and neck tumors

International Nuclear Information System (INIS)

Roedel, R.; Palmedo, H.; Reichmann, K.; Reinhardt, M.J.; Biersack, H.J.; Straehler-Pohl, H.J.; Jaeger, U.

2004-01-01

To evaluate the usefulness of combined PET/CT examinations for detection of malignant tumors and their metastases in head and neck oncology. 51 patients received whole body scans on a dual modality PET/CT system. CT was performed without i.v. contrast. The results were compared concerning the diagnostic impact of native CT scan on FDG-PET images and the additional value of fused imaging. From 153 lesions were 97 classified as malignant on CT and 136 on FDG/PET images, as suspicious for malignancy in 33 on CT and 7 on FDG-PET and as benign in 23 on CT and 10 on FDG-PET. With combined PET/CT all primary and recurrent tumors could be found, the detection rate in patients with unknown primary tumors was 45%. Compared to PET or CT alone the sensitivity, specifity and accuracy could be significantly improved by means of combined PET/CT. Fused PET/CT imaging with [F18]-FDG and native CT-scanning enables accurate diagnosis in 93% of lesions and 90% of patients with head and neck oncology. (orig.) [de

An attenuation correction method for PET/CT images

International Nuclear Information System (INIS)

Ue, Hidenori; Yamazaki, Tomohiro; Haneishi, Hideaki

2006-01-01

In PET/CT systems, accurate attenuation correction can be achieved by creating an attenuation map from an X-ray CT image. On the other hand, respiratory-gated PET acquisition is an effective method for avoiding motion blurring of the thoracic and abdominal organs caused by respiratory motion. In PET/CT systems employing respiratory-gated PET, using an X-ray CT image acquired during breath-holding for attenuation correction may have a large effect on the voxel values, especially in regions with substantial respiratory motion. In this report, we propose an attenuation correction method in which, as the first step, a set of respiratory-gated PET images is reconstructed without attenuation correction, as the second step, the motion of each phase PET image from the PET image in the same phase as the CT acquisition timing is estimated by the previously proposed method, as the third step, the CT image corresponding to each respiratory phase is generated from the original CT image by deformation according to the motion vector maps, and as the final step, attenuation correction using these CT images and reconstruction are performed. The effectiveness of the proposed method was evaluated using 4D-NCAT phantoms, and good stability of the voxel values near the diaphragm was observed. (author)

Cross sectional imaging of cardiac tumors

International Nuclear Information System (INIS)

Maksimovic, R.

2012-01-01

Full text: Primary cardiac tumors are a rare entity whose incidence, according to surgery and autopsy reports, is 0.3% to 0.7% of all cardiac tumors. Metastasis to the heart from other primary cancers is 30 times more common. Only 25% of primary cardiac tumors are malignant, and, of these, 75% are sarcomas. Malignant primary cardiac sarcomas are usually located in the right atrium and are most commonly angiosarcoma. In the left atrium, the most common malignant tumors are pleomorphic sarcoma and leiomyosarcoma. Symptom presentation for cardiac tumors is quite varied, but it is dependent upon tumor location and size, rather than upon histologic characteristics. Presentation includes congestive heart failure from intracardiac obstruction, systemic embolization, constitutional symptoms, and arrhythmias. Left atrial sarcomas tend to be more solid and less infiltrative than right-sided sarcomas; consequently, they tend to metastasize later. They usually present with symptoms of blood-flow obstruction and substantial, life-threatening congestive heart failure. Right-sided cardiac tumors are usually malignant and appear as bulky, infiltrative masses that grow in an outward pattern. These are usually fast-growing tumors that metastasize early and do not present with congestive heart failure until late in the disease. The diagnosis of cardiac tumors relies heavily on the use of multiple imaging techniques, including cardiac computed tomography (CT), cardiovascular magnetic resonance (CMR), and echocardiography. Important imaging data to collect include information on the size of the intracardiac mass, the mobility of the mass (an important predictor of prognosis and embolic potential), myocardial invasion, and cardiac chamber location. These factors will provide the means to diagnosis and prognosis. Other important data to collect include the mechanism of tumor implantation, the relationship of the tumor with adjacent structures, the surgeon route of access to the heart

Dual source CT imaging

International Nuclear Information System (INIS)

Seidensticker, Peter R.; Hofmann, Lars K.

2008-01-01

The introduction of Dual Source Computed Tomography (DSCT) in 2005 was an evolutionary leap in the field of CT imaging. Two x-ray sources operated simultaneously enable heart-rate independent temporal resolution and routine spiral dual energy imaging. The precise delivery of contrast media is a critical part of the contrast-enhanced CT procedure. This book provides an introduction to DSCT technology and to the basics of contrast media administration followed by 25 in-depth clinical scan and contrast media injection protocols. All were developed in consensus by selected physicians on the Dual Source CT Expert Panel. Each protocol is complemented by individual considerations, tricks and pitfalls, and by clinical examples from several of the world's best radiologists and cardiologists. This extensive CME-accredited manual is intended to help readers to achieve consistently high image quality, optimal patient care, and a solid starting point for the development of their own unique protocols. (orig.)

Photon CT scanning of advanced ceramic materials

International Nuclear Information System (INIS)

Sawicka, B.D.; Ellingson, W.A.

1987-02-01

Advanced ceramic materials are being developed for high temperature applications in advanced heat engines and high temperature heat recovery systems. Small size flaws (10 - 200 μm) and small nonuniformities in density distributions (0.1 -2%) present as long-range density gradients, are critical in most ceramics and their detection is of crucial importance. Computed tomographic (CT) imaging provides a means of obtaining a precise two-dimensional density map of a cross section through an object from which accurate information about small flaws and small density gradients can be obtained. With the use of high energy photon sources high contrast CT images can be obtained for both low and high density ceramics. In the present paper we illustrate the applicability of the photon CT technique to the examination of advanced ceramics. CT images of sintered alumina tiles are presented from which data on high-density inclusions, cracks and density gradients have been extracted

PET/CT. Dose-escalated image fusion?

International Nuclear Information System (INIS)

Brix, G.; Beyer, T.

2005-01-01

Clinical studies demonstrate a gain in diagnostic accuracy by employing combined PET/CT instead of separate CT and PET imaging. However, whole-body PET/CT examinations result in a comparatively high radiation burden to patients and thus require a proper justification and optimization to avoid repeated exposure or over-exposure of patients. This review article summarizes relevant data concerning radiation exposure of patients resulting from the different components of a combined PET/CT examination and presents different imaging strategies that can help to balance the diagnostic needs and the radiation protection requirements. In addition various dose reduction measures are discussed, some of which can be adopted from CT practice, while others mandate modifications to the existing hard- and software of PET/CT systems. (orig.)

Quality assurance of CT-PET alignment and image registration for radiation treatment planning

International Nuclear Information System (INIS)

Gong, S.J.; O'Keefe, G.J.; Gunawardana, D.H.

2005-01-01

A multi-layer point source phantom was first used to calibrate and verify the CT-PET system alignment. A partial whole-body Aldcrson RANDO Man Phantom (head through mid-femur) was externally and internally marked with small metal cannulas filled with 18F-FDG and then scanned with both modalities. Six series of phantom studies with different acquisition settings and scan positions were performed to reveal possible system bias and evaluate the accuracy and reliabilities of Philips Syntegra program in image alignment, coregistration and fusion. The registration error was assessed quantitatively by measuring the root-mean-square distance between the iso-centers of corresponding fiducial marker geometries in reference CT volumes and transformed CT or PET volumes. Results: Experimental data confirms the accuracy of manual, parameter, point and image-based registration using Syntegra is better than 2 mm. Comparisons between blind and cross definition of iso-centers of fiducial marks indicate that the fused CT and PET is superior to visual correlation of CT and PET side-by-side. Conclusion: In this work we demonstrate the QA procedures of Gemini image alignment and registration. Syntegra produces intrinsic and robust multi-modality image registration and fusion with careful user interaction. The registration accuracy is generally better than the spatial resolution of the PET scanner used and this appears to be sufficient for most RTP CT-PET registration procedures

Deep 3D convolution neural network for CT brain hemorrhage classification

Science.gov (United States)

Jnawali, Kamal; Arbabshirani, Mohammad R.; Rao, Navalgund; Patel, Alpen A.

2018-02-01

Intracranial hemorrhage is a critical conditional with the high mortality rate that is typically diagnosed based on head computer tomography (CT) images. Deep learning algorithms, in particular, convolution neural networks (CNN), are becoming the methodology of choice in medical image analysis for a variety of applications such as computer-aided diagnosis, and segmentation. In this study, we propose a fully automated deep learning framework which learns to detect brain hemorrhage based on cross sectional CT images. The dataset for this work consists of 40,367 3D head CT studies (over 1.5 million 2D images) acquired retrospectively over a decade from multiple radiology facilities at Geisinger Health System. The proposed algorithm first extracts features using 3D CNN and then detects brain hemorrhage using the logistic function as the last layer of the network. Finally, we created an ensemble of three different 3D CNN architectures to improve the classification accuracy. The area under the curve (AUC) of the receiver operator characteristic (ROC) curve of the ensemble of three architectures was 0.87. Their results are very promising considering the fact that the head CT studies were not controlled for slice thickness, scanner type, study protocol or any other settings. Moreover, the proposed algorithm reliably detected various types of hemorrhage within the skull. This work is one of the first applications of 3D CNN trained on a large dataset of cross sectional medical images for detection of a critical radiological condition

Image mottle in abdominal CT.

Science.gov (United States)

Ende, J F; Huda, W; Ros, P R; Litwiller, A L

1999-04-01

To investigate image mottle in conventional CT images of the abdomen as a function of radiographic technique factors and patient size. Water-filled phantoms simulating the abdomens of adult (32 cm in diameter) and pediatric (16 cm in diameter) patients were used to investigate image mottle in CT as a function of x-ray tube potential and mAs. CT images from 39 consecutive patients with noncontrast liver scans and 49 patients with iodine contrast scans were analyzed retrospectively. Measurements were made of the mean liver parenchyma Hounsfield unit value and the corresponding image mottle. For a given water phantom and x-ray tube potential, image mottle was proportional to the mAs-0.5. Increasing the phantom diameter from 16 cm (pediatric) to 32 cm increased the mottle by a factor of 2.4, and increasing the x-ray tube potential from 80 kVp to 140 kVp reduced the mottle by a factor of 2.5. All patients were scanned at 120 kVp, with no correlation between patient size and the x-ray tube mAs. The mean mottle level was 7.8 +/- 2.2 and 10.0 +/- 2.5 for the noncontrast and contrast studies, respectively. An increase in patient diameter of 3 cm would require approximately 65% more mAs to maintain the same level of image mottle. The mottle in abdominal CT images may be controlled by adjusting radiographic technique factors, which should be adjusted to take into account the size of the patient undergoing the examination.

Dual energy CT: New horizon in medical imaging

Energy Technology Data Exchange (ETDEWEB)

Goo, Hyun Woo [Dept. of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Goo, Jin Mo [Dept. of Radiology, Seoul National University College of Medicine, Seoul (Korea, Republic of)

2017-08-01

Dual-energy CT has remained underutilized over the past decade probably due to a cumbersome workflow issue and current technical limitations. Clinical radiologists should be made aware of the potential clinical benefits of dual-energy CT over single-energy CT. To accomplish this aim, the basic principle, current acquisition methods with advantages and disadvantages, and various material-specific imaging methods as clinical applications of dual-energy CT should be addressed in detail. Current dual-energy CT acquisition methods include dual tubes with or without beam filtration, rapid voltage switching, dual-layer detector, split filter technique, and sequential scanning. Dual-energy material-specific imaging methods include virtual monoenergetic or monochromatic imaging, effective atomic number map, virtual non-contrast or unenhanced imaging, virtual non-calcium imaging, iodine map, inhaled xenon map, uric acid imaging, automatic bone removal, and lung vessels analysis. In this review, we focus on dual-energy CT imaging including related issues of radiation exposure to patients, scanning and post-processing options, and potential clinical benefits mainly to improve the understanding of clinical radiologists and thus, expand the clinical use of dual-energy CT; in addition, we briefly describe the current technical limitations of dual-energy CT and the current developments of photon-counting detector.

Dual-Energy CT: New Horizon in Medical Imaging.

Science.gov (United States)

Goo, Hyun Woo; Goo, Jin Mo

2017-01-01

Dual-energy CT has remained underutilized over the past decade probably due to a cumbersome workflow issue and current technical limitations. Clinical radiologists should be made aware of the potential clinical benefits of dual-energy CT over single-energy CT. To accomplish this aim, the basic principle, current acquisition methods with advantages and disadvantages, and various material-specific imaging methods as clinical applications of dual-energy CT should be addressed in detail. Current dual-energy CT acquisition methods include dual tubes with or without beam filtration, rapid voltage switching, dual-layer detector, split filter technique, and sequential scanning. Dual-energy material-specific imaging methods include virtual monoenergetic or monochromatic imaging, effective atomic number map, virtual non-contrast or unenhanced imaging, virtual non-calcium imaging, iodine map, inhaled xenon map, uric acid imaging, automatic bone removal, and lung vessels analysis. In this review, we focus on dual-energy CT imaging including related issues of radiation exposure to patients, scanning and post-processing options, and potential clinical benefits mainly to improve the understanding of clinical radiologists and thus, expand the clinical use of dual-energy CT; in addition, we briefly describe the current technical limitations of dual-energy CT and the current developments of photon-counting detector.

An approach for quantitative image quality analysis for CT

Science.gov (United States)

Rahimi, Amir; Cochran, Joe; Mooney, Doug; Regensburger, Joe

2016-03-01

An objective and standardized approach to assess image quality of Compute Tomography (CT) systems is required in a wide variety of imaging processes to identify CT systems appropriate for a given application. We present an overview of the framework we have developed to help standardize and to objectively assess CT image quality for different models of CT scanners used for security applications. Within this framework, we have developed methods to quantitatively measure metrics that should correlate with feature identification, detection accuracy and precision, and image registration capabilities of CT machines and to identify strengths and weaknesses in different CT imaging technologies in transportation security. To that end we have designed, developed and constructed phantoms that allow for systematic and repeatable measurements of roughly 88 image quality metrics, representing modulation transfer function, noise equivalent quanta, noise power spectra, slice sensitivity profiles, streak artifacts, CT number uniformity, CT number consistency, object length accuracy, CT number path length consistency, and object registration. Furthermore, we have developed a sophisticated MATLAB based image analysis tool kit to analyze CT generated images of phantoms and report these metrics in a format that is standardized across the considered models of CT scanners, allowing for comparative image quality analysis within a CT model or between different CT models. In addition, we have developed a modified sparse principal component analysis (SPCA) method to generate a modified set of PCA components as compared to the standard principal component analysis (PCA) with sparse loadings in conjunction with Hotelling T2 statistical analysis method to compare, qualify, and detect faults in the tested systems.

KINKFOLD—an AutoLISP program for construction of geological cross-sections using borehole image data

Science.gov (United States)

Özkaya, Sait Ismail

2002-04-01

KINKFOLD is an AutoLISP program designed to construct geological cross-sections from borehole image or dip meter logs. The program uses the kink-fold method for cross-section construction. Beds are folded around hinge lines as angle bisectors so that bedding thickness remains unchanged. KINKFOLD may be used to model a wide variety of parallel fold structures, including overturned and faulted folds, and folds truncated by unconformities. The program accepts data from vertical or inclined boreholes. The KINKFOLD program cannot be used to model fault drag, growth folds, inversion structures or disharmonic folds where the bed thickness changes either because of deformation or deposition. Faulted structures and similar folds can be modelled by KINKFOLD by omitting dip measurements within fault drag zones and near axial planes of similar folds.

Pulmonary hypertension CT imaging

International Nuclear Information System (INIS)

Nedevska, A.

2013-01-01

Full text: The right heart catheterization is the gold standard in the diagnosis and determines the severity of pulmonary hypertension. The significant technical progress of noninvasive diagnostic imaging methods significantly improves the pixel density and spatial resolution in the study of cardiovascular structures, thus changes their role and place in the overall diagnostic plan. Learning points: What is the etiology, clinical manifestation and general pathophysiological disorders in pulmonary hypertension. What are the established diagnostic methods in the diagnosis and follow-up of patients with pulmonary hypertension. What is the recommended protocol for CT scanning for patients with clinically suspected or documented pulmonary hypertension. What are the important diagnostic findings in CT scan of a patient with pulmonary hypertension. Discussion: The prospect of instantaneous complex - anatomical and functional cardiopulmonary and vascular diagnostics seems extremely attractive. The contrast enhanced multislice computed (CT ) and magnetic resonance imaging are very suitable methods for imaging the structures of the right heart, with the possibility of obtaining multiple projections and three-dimensional imaging reconstructions . There are specific morphological features that, if carefully analyzed, provide diagnostic information. Thus, it is possible to avoid or at least reduce the frequency of use of invasive diagnostic cardiac catheterization in patients with pulmonary hypertension. Conclusion: This review focuses on the use of contrast-enhanced CT for comprehensive evaluation of patients with pulmonary hypertension and presents the observed characteristic changes in the chest, lung parenchyma , the structures of the right half of the heart and pulmonary vessels

SU-E-U-02: The Development of a Practical Ultrasonic System for Cross-Sectional Imaging of Small Animals

Energy Technology Data Exchange (ETDEWEB)

Kamp, J [Wayne State University, Detroit, MI (United States); Karmanos Cancer Institute - International Imaging Center, Detroit, MI (United States); Malyarenko, E [Karmanos Cancer Institute - International Imaging Center, Detroit, MI (United States); Tessonics Corp, Birmingham, MI (United Kingdom); Chen, D [Karmanos Cancer Institute - International Imaging Center, Detroit, MI (United States); Wydra, A [True Phantoms Solutions, Windsor, ON (Canada); University of Windsor - Institute for Diagnostic Imaging Research, Windsor, ON (Canada); Maev, R [Wayne State University, Detroit, MI (United States); Karmanos Cancer Institute - International Imaging Center, Detroit, MI (United States); Tessonics Corp, Birmingham, MI (United Kingdom); True Phantoms Solutions, Windsor, ON (Canada); University of Windsor - Institute for Diagnostic Imaging Research, Windsor, ON (Canada)

2015-06-15

Purpose: To test the feasibility of developing a practical medium frequency ultrasound tomography method for small animal imaging. The ability to produce cross-sectional or full body images of a live small animal using a low-cost tabletop ultrasound scanner without any special license would be very beneficial to long term biological studies, where repeated scanning is often required over an extended period of time. Methods: The cross sectional images were produced by compounding multiple B-scans of a laboratory phantom or an animal acquired at different projection angles. Two imaging systems were used to test the concept. The first system included a programmable 64-channel phased array controller driving a 128-channel, 5–10 MHz linear probe to produce 143 B-Mode projections of the spinning object. The second system designed and manufactured in house, produced 64 or 128 B-Mode projections with a single unfocused 8 MHz transducer scanning with a 0.116 mm step size. Results: The phased array system provided good penetration through the phantoms/mice (with the exception of the lungs) and allowed to acquire data in a very short time. The cross-sectional images have enough resolution and dynamic range to detect both high- and low-contrast organs. The single transducer system takes longer to scan, and the data require more sophisticated processing. To date, our images allow seeing details as small as 1–2 mm in the phantoms and in small animals, with the contrast mostly due to highly reflecting bones and air inclusions. Conclusion: The work indicates that very detailed and anatomically correct images can be created by relatively simple and inexpensive means. With more advanced algorithms and improved system design, scan time can be reduced considerably, enabling high-resolution full 3D imaging. This will allow for quick and easy scans that can help monitor tumor growth and/or regression without contributing any dose to the animal. The authors would like to acknowledge

Applying microCT and 3D visualization to Jurassic silicified conifer seed cones: A virtual advantage over thin-sectioning1

Science.gov (United States)

Gee, Carole T.

2013-01-01

• Premise of the study: As an alternative to conventional thin-sectioning, which destroys fossil material, high-resolution X-ray computed tomography (also called microtomography or microCT) integrated with scientific visualization, three-dimensional (3D) image segmentation, size analysis, and computer animation is explored as a nondestructive method of imaging the internal anatomy of 150-million-year-old conifer seed cones from the Late Jurassic Morrison Formation, USA, and of recent and other fossil cones. • Methods: MicroCT was carried out on cones using a General Electric phoenix v|tome|x s 240D, and resulting projections were processed with visualization software to produce image stacks of serial single sections for two-dimensional (2D) visualization, 3D segmented reconstructions with targeted structures in color, and computer animations. • Results: If preserved in differing densities, microCT produced images of internal fossil tissues that showed important characters such as seed phyllotaxy or number of seeds per cone scale. Color segmentation of deeply embedded seeds highlighted the arrangement of seeds in spirals. MicroCT of recent cones was even more effective. • Conclusions: This is the first paper on microCT integrated with 3D segmentation and computer animation applied to silicified seed cones, which resulted in excellent 2D serial sections and segmented 3D reconstructions, revealing features requisite to cone identification and understanding of strobilus construction. PMID:25202495

The role of CT and MR in diagnosis of aortic dissection

International Nuclear Information System (INIS)

Yoon, Kwon Ha; Lim, Tae Hwan; Song, Koun Sik; Min, Kyung Seok; Song, Meong Gun

1994-01-01

The purpose of this study was to determine the role of CT and MR imagings in the diagnosis of aortic dissection and differentiation between the true and false lumen. We retrospectively studied forty patients with aortic dissection(AD) diagnosed by imagings or surgery. Of the forty patients, 19 were examined with only CT, 14 with CT and MR, and 7 with MR. Our points of view were(1) the classification of AD according to configuration of intimal flap by cross-sectional imaging, (2) differentiation between the true and false lumens, (3) the course of the false lumen, and (4) detectability of the origin of major branch vessels of the abdominal aorta. The classification by cross-sectional imaging were crescentic(65%), circumferential(15%), flat(12%), and irregular(8%) type, in which false negative diagnosis was made in 1 case of crescentic and circumferential type, respectively. In 2 case of flat type and 1 case of irregular type, the differentiation between the true and false lumen was impossible with CT. The course of the false lumen in descending thoracic aorta revealed counterclock wise rotation(66%), clockwise rotation(5%) or fixed(29%) appearance. MR imaging was superior to CT in the detection of the origin of major branch vessels of the abdominal aorta. The determination of the origin of major branches of abdominal aorta arising from the true and false lumen were impossible in 2 cases in which only CT was done. Diagnosis of crescentic and circumferential types of AD with narrow and thrombosed false lumen was problematic in both CT and MR with no difference of diagnostic accuracy between the two modalities. The differentiation between the true and false lumen was difficult in flat and irregular types with only CT. Therefore, when surgical treatment is considered as in type B aortic dissection, MR imaging is recommended in order to determine the origin of major branch vessels

Tendon retraction with rotator cuff tear causes a decrease in cross-sectional area of the supraspinatus muscle on magnetic resonance imaging.

Science.gov (United States)

Fukuta, Shoji; Tsutsui, Takahiko; Amari, Rui; Wada, Keizo; Sairyo, Koichi

2016-07-01

Muscle atrophy and fatty degeneration of the rotator cuff muscles have been reported as negative prognostic indicators after rotator cuff repair. Although the Y-shaped view is widely used for measuring the cross-sectional area of the supraspinatus muscle, the contribution of retraction of the torn tendon as well as muscle atrophy must be considered. The purpose of this study was to clarify the relationship between cross-sectional area and tendon retraction or size of the tear. This study included 76 shoulders that were evaluated arthroscopically for the presence and size of tears. Cross-sectional areas of rotator cuff muscles were measured from the Y-shaped view to 3 more medial slices. The occupation ratio and tangent sign were evaluated on the Y-shaped view. The retraction of torn tendon was also measured on the oblique coronal images. On the Y-shaped view, the cross-sectional area of the supraspinatus and the occupation ratio decreased in conjunction with the increase in tear size. A significant decrease in cross-sectional area was noted only in large and massive tears on more medial slices from the Y-shaped view. Significant decreases in the cross-sectional area of the infraspinatus were observed in large and massive tears on all images. A negative correlation was found between tendon retraction and cross-sectional area, which was strongest on the Y-shaped view. To avoid the influence of retraction of the supraspinatus tendon, sufficient medial slices from the musculotendinous junction should be used for evaluation of muscle atrophy. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Ring artifacts removal from synchrotron CT image slices

International Nuclear Information System (INIS)

Wei Zhouping; Chapman, Dean; Wiebe, Sheldon

2013-01-01

Ring artifacts can occur in reconstructed images from x-ray Computerized Tomography (CT) as full or partial concentric rings superimposed on the scanned structures. Due to the data corruption by those ring artifacts in CT images, qualitative and quantitative analysis of these images are compromised. In this paper, we propose to correct the ring artifacts on the reconstructed synchrotron radiation (SR) CT image slices. The proposed correction procedure includes the following steps: (1). transform the reconstructed CT images into polar coordinates; (2) apply discrete two-dimensional (2D) wavelet transform to the polar image to decompose it into four image components: low pass band image component, as well as the components from horizontal, vertical and diagonal details bands; (3). apply 2D Fourier transform to the vertical details band image component only, since the ring artifacts become vertical lines in the polar coordinates; (4). apply Gaussian filtering in Fourier domain along the abscissa direction to suppress the vertical lines, since the information of the vertical lines in Fourier domain is completely condensed to that direction; (5). perform inverse Fourier transform to get the corrected vertical details band image component; (6). perform inverse wavelet transform to get the corrected polar image; (7). transform the corrected polar image back to Cartesian coordinates to get the CT image slice with reduced ring artifacts. This approach has been successfully used on CT data acquired from the Biomedical Imaging and Therapy (BMIT) beamline in Canadian Light Source (CLS), and the results show that the ring artifacts in original SR CT images have been effectively suppressed with all the structure information in the image preserved.

A morphological study of the mandibular molar region using reconstructed helical computed tomographic images

International Nuclear Information System (INIS)

Tsuno, Hiroaki; Noguchi, Makoto; Noguchi, Akira; Yoshida, Keiko; Tachinami, Yasuharu

2010-01-01

This study investigated the morphological variance in the mandibular molar region using reconstructed helical computed tomographic (CT) images. In addition, we discuss the necessity of CT scanning as part of the preoperative assessment process for dental implantation, by comparing the results with the findings of panoramic radiography. Sixty patients examined using CT as part of the preoperative assessment for dental implantation were analyzed. Reconstructed CT images were used to evaluate the bone quality and cross-sectional bone morphology of the mandibular molar region. The mandibular cortical index (MCI) and X-ray density ratio of this region were assessed using panoramic radiography in order to analyze the correlation between the findings of the CT images and panoramic radiography. CT images showed that there was a decrease in bone quality in cases with high MCI. Cross-sectional CT images revealed that the undercuts on the lingual side in the highly radiolucent areas in the basal portion were more frequent than those in the alveolar portion. This study showed that three-dimensional reconstructed CT images can help to detect variances in mandibular morphology that might be missed by panoramic radiography. In conclusion, it is suggested that CT should be included as an important examination tool before dental implantation. (author)

Combined X-ray CT and mass spectrometry for biomedical imaging applications

Science.gov (United States)

Schioppa, E., Jr.; Ellis, S.; Bruinen, A. L.; Visser, J.; Heeren, R. M. A.; Uher, J.; Koffeman, E.

2014-04-01

Imaging technologies play a key role in many branches of science, especially in biology and medicine. They provide an invaluable insight into both internal structure and processes within a broad range of samples. There are many techniques that allow one to obtain images of an object. Different techniques are based on the analysis of a particular sample property by means of a dedicated imaging system, and as such, each imaging modality provides the researcher with different information. The use of multimodal imaging (imaging with several different techniques) can provide additional and complementary information that is not possible when employing a single imaging technique alone. In this study, we present for the first time a multi-modal imaging technique where X-ray computerized tomography (CT) is combined with mass spectrometry imaging (MSI). While X-ray CT provides 3-dimensional information regarding the internal structure of the sample based on X-ray absorption coefficients, MSI of thin sections acquired from the same sample allows the spatial distribution of many elements/molecules, each distinguished by its unique mass-to-charge ratio (m/z), to be determined within a single measurement and with a spatial resolution as low as 1 μm or even less. The aim of the work is to demonstrate how molecular information from MSI can be spatially correlated with 3D structural information acquired from X-ray CT. In these experiments, frozen samples are imaged in an X-ray CT setup using Medipix based detectors equipped with a CO2 cooled sample holder. Single projections are pre-processed before tomographic reconstruction using a signal-to-thickness calibration. In the second step, the object is sliced into thin sections (circa 20 μm) that are then imaged using both matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) and secondary ion (SIMS) mass spectrometry, where the spatial distribution of specific molecules within the sample is determined. The

The value of the 3D CT imaging in diagnosis of lumbar spondylolysis

International Nuclear Information System (INIS)

Krupski, W.; Paslawski, M.; Zlomaniec, J.; Fatyga, M.; Majcher, P.

2003-01-01

The frequent cause of a low back pain is the lumbar spondylolysis and the spondylolisthesis. The purpose of the study was to assess of the value of three-dimensional CT imaging in diagnosis of the lumbar spondylolysis. Material comprises of 22 patients complaining from low back pain in which lateral radiograms, axial CT scans, MPR and 3D reconstructions were performed. The presence of spondylolysis, spondylolisthesis, stenosis of the spinal canal and intervertebral foramens were assessed. The differences in diagnostic value between analysed imaging modalities in revealing spondylolysis, spondylolisthesis and narrowing of intervertebral foramens, were statistically highly significant. The highest sensitivity in recognition of these pathologies was observed in 3D reconstruction. The 3D reconstructions were also useful in an assessment of the spinal canal stenosis, revealing degenerative changes, but the increased number of diagnosed pathologies was not statistically significant comparing with axial CT section. Spondylolysis was diagnosed in 22 patients based on 3D reconstructions, in 14 patients on MPR reconstructions, in 18 patients on axial sections and only in 8 cases on lateral radiograms. Spondylolisthesis was visible on lateral radiograms in 21 patients, on axial scans in 12 patients, and in 22 cases, on both MPR and 3D reconstruction. The stenosis of the spinal canal was found on lateral radiograms in 2 patients, on MPR reconstruction in 4 cases, and in 7 patients on 3D reconstruction. The intervertebral foramen stenosis was present in 5 patients, based on MPR reconstruction and in 17, on spatial images. Spatial 3D CT reconstructions are superior to lateral radiograms, axial CT sections and MPR reconstruction in revealing spondylolysis, spondylolisthesis and stenosis of intervertebral foramens. They are useful in assessment of spinal canal narrowing and evaluation of degenerative changes. In our opinion 3D CT reconstruction projected from the inside of the

CT anatomy of hilar lymphadenopathy

International Nuclear Information System (INIS)

Sone, S.; Higashihara, T.; Morimoto, S.; Ikezoe, J.; Arisawa, J.; Monden, Y.; Nahakara, K.

1983-01-01

The normal distributions of lymph nodes in the pulmonary hili is diagrammatically shown with a typical computed tomographic (CT) demonstration of hilar lymphadenopathy. On the basis of observations in anatomic cross sections of cadaver lungs, the lympth nodes in the right lung can be divided into four principal groups (right upper lobe, interlobar, middle lobe, and lower lobe) and in the left lung into three principal groups (left upper lobe, interlobar, and lower lobe). Most of the hilar lymph nodes are situated along the bronchi in close relation with the pulmonary vascular branches. Because of this close proximity, contrast-enhanced CT images are indispensable for precise CT interpretation of a hilar lymphadenopathy

CT urethrography. New imaging technique of the urethra

International Nuclear Information System (INIS)

Takeyama, Nobuyuki; Munechika, Hirotsugu

2005-01-01

The purpose of the study is to assess the usefulness of CT urethrography for evaluation of the posterior urethra and surrounding structures. The CT images were performed with 4 channel multidetector row CT unit. Twenty-six cases (12 cases of CT urethrography and 14 cases of conventional urethrography) were included in this study. 3D-volume rendering (VR) images and VR-multiplaner reconstruction (MPR) sagittal images were compared with conventional retrograde urethrography (RUG) images to evaluate the following anatomical structures; the inferior wall of bladder, the neck of bladder, the posterior urethra, and the prostate. Two radiologists undertook a task of evaluation of the images. There was no significant difference in image quality between RUG and 3D-VR. However, VR-MPR sagittal images were significantly better than RUG or 3D-VR images in any anatomical structures set up beforehand for evaluation. CT urerthrography was useful for evaluation of the posterior urethra and surrounding structures. (author)

Risk factors for morbidity and death in non-cystic fibrosis bronchiectasis: a retrospective cross-sectional analysis of CT diagnosed bronchiectatic patients

Directory of Open Access Journals (Sweden)

Goeminne Pieter

2012-03-01

Full Text Available Abstract Introduction There is a relative lack of information about the death rate and morbidity of non-cystic fibrosis bronchiectasis and most studies are limited due to referral bias. We wanted to assess death rate and morbidity in those patients at our hospital. Methods Adult patients seen at our department between June 2006 and November 2009 were recruited if the key string "bronchiect-" was mentioned in electronic clinical records and if chest CT imaging was available. Clinical records of all patients with confirmed radiologic diagnosis of bronchiectasis were reviewed and clinical characteristics were analyzed. Results 539 patients with a radiographic diagnosis of non-cystic fibrosis bronchiectasis were identified in a retrospective cross-sectional analysis giving a prevalence of 2.6% in our hospital population. A wide range of etiologies was found with idiopathic bronchiectasis in 26%. In the 41 months interval, 57 patients (10.6% died. We found a median exacerbation rate of 1.94 per year. Bacterial colonization status was associated with more deaths, exacerbation rate, symptoms and reduced pulmonary function. Pulmonary hypertension was found in 48% of our patients. Conclusions We evaluated a large non-cystic fibrosis bronchiectasis population, and provided new epidemiological data on associations between clinical characteristics and deaths and morbidity in these patients.

Applying an animal model to quantify the uncertainties of an image-based 4D-CT algorithm

International Nuclear Information System (INIS)

Pierce, Greg; Battista, Jerry; Wang, Kevin; Lee, Ting-Yim

2012-01-01

The purpose of this paper is to use an animal model to quantify the spatial displacement uncertainties and test the fundamental assumptions of an image-based 4D-CT algorithm in vivo. Six female Landrace cross pigs were ventilated and imaged using a 64-slice CT scanner (GE Healthcare) operating in axial cine mode. The breathing amplitude pattern of the pigs was varied by periodically crimping the ventilator gas return tube during the image acquisition. The image data were used to determine the displacement uncertainties that result from matching CT images at the same respiratory phase using normalized cross correlation (NCC) as the matching criteria. Additionally, the ability to match the respiratory phase of a 4.0 cm subvolume of the thorax to a reference subvolume using only a single overlapping 2D slice from the two subvolumes was tested by varying the location of the overlapping matching image within the subvolume and examining the effect this had on the displacement relative to the reference volume. The displacement uncertainty resulting from matching two respiratory images using NCC ranged from 0.54 ± 0.10 mm per match to 0.32 ± 0.16 mm per match in the lung of the animal. The uncertainty was found to propagate in quadrature, increasing with number of NCC matches performed. In comparison, the minimum displacement achievable if two respiratory images were matched perfectly in phase ranged from 0.77 ± 0.06 to 0.93 ± 0.06 mm in the lung. The assumption that subvolumes from separate cine scan could be matched by matching a single overlapping 2D image between to subvolumes was validated. An in vivo animal model was developed to test an image-based 4D-CT algorithm. The uncertainties associated with using NCC to match the respiratory phase of two images were quantified and the assumption that a 4.0 cm 3D subvolume can by matched in respiratory phase by matching a single 2D image from the 3D subvolume was validated. The work in this paper shows the image-based 4D-CT

Evaluation of Marfan syndrome: MR imaging versus CT

International Nuclear Information System (INIS)

Soulen, R.L.; Fishman, E.K.; Pyeritz, R.E.; Gott, V.L.; Zerhouni, E.A.

1986-01-01

Twenty-five patients with Marfan, syndrome underwent both CT and MR imaging. MR imaging were interpreted in blinded fashion and then compared with CT scans MR imaging was found to be equivalent to CT in the detection of aortic, dural, and hip abnormalities in patients not operated on. MR imaging was superior to CT in the evaluation of postoperative patients because the artifact produced by Bjork-Shirley or St. Jude valves precludes adequate evaluation of the aortic root on CT while producing only a small inferior field distortion (a ''pseudo-ventricular septal defect'') on MR imaging. The absence of radiation exposure is another major advantage of MR imaging in this relatively young population requiring serial studies. The authors conclude that MR imaging is the modality of choice for the evaluation and follow-up of patients with Marfan syndrome and offers an appropriate means of screening their kindred

Mass preserving image registration for lung CT

DEFF Research Database (Denmark)

Gorbunova, Vladlena; Sporring, Jon; Lo, Pechin Chien Pau

2012-01-01

This paper presents a mass preserving image registration algorithm for lung CT images. To account for the local change in lung tissue intensity during the breathing cycle, a tissue appearance model based on the principle of preservation of total lung mass is proposed. This model is incorporated...... on four groups of data: 44 pairs of longitudinal inspiratory chest CT scans with small difference in lung volume; 44 pairs of longitudinal inspiratory chest CT scans with large difference in lung volume; 16 pairs of expiratory and inspiratory CT scans; and 5 pairs of images extracted at end exhale and end...

Reliability of computed tomography measurements in assessment of thigh muscle cross-sectional area and attenuation

International Nuclear Information System (INIS)

Strandberg, Sören; Wretling, Marie-Louise; Wredmark, Torsten; Shalabi, Adel

2010-01-01

Advancement in technology of computer tomography (CT) and introduction of new medical imaging softwares enables easy and rapid assessment of muscle cross-sectional area (CSA) and attenuation. Before using these techniques in clinical studies there is a need for evaluation of the reliability of the measurements. The purpose of the study was to evaluate the inter- and intra-observer reliability of ImageJ in measuring thigh muscles CSA and attenuation in patients with anterior cruciate ligament (ACL) injury by computer tomography. 31 patients from an ongoing study of rehabilitation and muscle atrophy after ACL reconstruction were included in the study. Axial CT images with slice thickness of 10 mm at the level of 150 mm above the knee joint were analyzed by two investigators independently at two times with a minimum of 3 weeks between the two readings using NIH ImageJ. CSA and the mean attenuation of individual thigh muscles were analyzed for both legs. Mean CSA and mean attenuation values were in good agreement both when comparing the two observers and the two replicates. The inter- and intraclass correlation (ICC) was generally very high with values from 0.98 to 1.00 for all comparisons except for the area of semimembranosus. All the ICC values were significant (p < 0,001). Pearson correlation coefficients were also generally very high with values from 0.98 to 1.00 for all comparisons except for the area of semimembranosus (0.95 for intraobserver and 0.92 for interobserver). This study has presented ImageJ as a method to monitor and evaluate CSA and attenuation of different muscles in the thigh using CT-imaging. The method shows an overall excellent reliability with respect to both observer and replicate

Image quality in children with low-radiation chest CT using adaptive statistical iterative reconstruction and model-based iterative reconstruction.

Directory of Open Access Journals (Sweden)

Jihang Sun

Full Text Available OBJECTIVE: To evaluate noise reduction and image quality improvement in low-radiation dose chest CT images in children using adaptive statistical iterative reconstruction (ASIR and a full model-based iterative reconstruction (MBIR algorithm. METHODS: Forty-five children (age ranging from 28 days to 6 years, median of 1.8 years who received low-dose chest CT scans were included. Age-dependent noise index (NI was used for acquisition. Images were retrospectively reconstructed using three methods: MBIR, 60% of ASIR and 40% of conventional filtered back-projection (FBP, and FBP. The subjective quality of the images was independently evaluated by two radiologists. Objective noises in the left ventricle (LV, muscle, fat, descending aorta and lung field at the layer with the largest cross-section area of LV were measured, with the region of interest about one fourth to half of the area of descending aorta. Optimized signal-to-noise ratio (SNR was calculated. RESULT: In terms of subjective quality, MBIR images were significantly better than ASIR and FBP in image noise and visibility of tiny structures, but blurred edges were observed. In terms of objective noise, MBIR and ASIR reconstruction decreased the image noise by 55.2% and 31.8%, respectively, for LV compared with FBP. Similarly, MBIR and ASIR reconstruction increased the SNR by 124.0% and 46.2%, respectively, compared with FBP. CONCLUSION: Compared with FBP and ASIR, overall image quality and noise reduction were significantly improved by MBIR. MBIR image could reconstruct eligible chest CT images in children with lower radiation dose.

In vivo microCT imaging of rodent cerebral vasculature

International Nuclear Information System (INIS)

Seo, Youngho; Hasegawa, Bruce H; Hashimoto, Tomoki; Nuki, Yoshitsugu

2008-01-01

Computed tomography (CT) remains a critical diagnostic tool for evaluating patients with cerebrovascular disease, and the advent of specialized systems for imaging rodents has extended these techniques to small animal models of these diseases. We therefore have evaluated in vivo methods of imaging rat models of hemorrhagic stroke using a high resolution compact computed tomography ('microCT') system (FLEX(tm) X-O(tm), Gamma Medica-Ideas, Northridge, CA). For all in vivo studies, the head of the anesthetized rat was secured in a custom immobilization device for microCT imaging with 512 projections over 2 min at 60 kVp and 0.530 mA (I tube x t/rotation = 63.6 mAs). First, imaging without iodinated contrast was performed (a) to differentiate the effect of contrast agent in contrast-enhanced CT and (b) to examine the effectiveness of the immobilization device between two time points of CT acquisitions. Then, contrast-enhanced CT was performed with continuous administration of iopromide (300 mgI ml -1 at 1.2 ml min -1 ) to visualize aneurysms and other vascular formations in the carotid and cerebral arteries that may precede subarachnoid hemorrhage. The accuracy of registration between the noncontrast and contrast-enhanced CT images with the immobilization device was compared against the images aligned with normalized mutual information using FMRIB's linear image registration tool (FLIRT). Translations and rotations were examined between the FLIRT-aligned noncontrast CT image and the nonaligned noncontrast CT image. These two data sets demonstrated translational and rotational differences of less than 0.5 voxel (∼85 μm) and 0.5 deg., respectively. Noncontrast CT demonstrated a very small volume (0.1 ml) of femoral arterial blood introduced surgically into the rodent brain. Continuous administration of iopromide during the CT acquisition produced consistent vascular contrast in the reconstructed CT images. As a result, carotid arteries and major cerebral blood vessels

In vivo microCT imaging of rodent cerebral vasculature

Energy Technology Data Exchange (ETDEWEB)

Seo, Youngho; Hasegawa, Bruce H [Center for Molecular and Functional Imaging, Department of Radiology, University of California, San Francisco, CA 94143 (United States); Hashimoto, Tomoki; Nuki, Yoshitsugu [Center for Cerebrovascular Research, Department of Anesthesia and Perioperative Care, University of California, San Francisco, CA 94143 (United States)], E-mail: youngho.seo@radiology.ucsf.edu

2008-04-07

Computed tomography (CT) remains a critical diagnostic tool for evaluating patients with cerebrovascular disease, and the advent of specialized systems for imaging rodents has extended these techniques to small animal models of these diseases. We therefore have evaluated in vivo methods of imaging rat models of hemorrhagic stroke using a high resolution compact computed tomography ('microCT') system (FLEX(tm) X-O(tm), Gamma Medica-Ideas, Northridge, CA). For all in vivo studies, the head of the anesthetized rat was secured in a custom immobilization device for microCT imaging with 512 projections over 2 min at 60 kVp and 0.530 mA (I{sub tube} x t/rotation = 63.6 mAs). First, imaging without iodinated contrast was performed (a) to differentiate the effect of contrast agent in contrast-enhanced CT and (b) to examine the effectiveness of the immobilization device between two time points of CT acquisitions. Then, contrast-enhanced CT was performed with continuous administration of iopromide (300 mgI ml{sup -1} at 1.2 ml min{sup -1}) to visualize aneurysms and other vascular formations in the carotid and cerebral arteries that may precede subarachnoid hemorrhage. The accuracy of registration between the noncontrast and contrast-enhanced CT images with the immobilization device was compared against the images aligned with normalized mutual information using FMRIB's linear image registration tool (FLIRT). Translations and rotations were examined between the FLIRT-aligned noncontrast CT image and the nonaligned noncontrast CT image. These two data sets demonstrated translational and rotational differences of less than 0.5 voxel ({approx}85 {mu}m) and 0.5 deg., respectively. Noncontrast CT demonstrated a very small volume (0.1 ml) of femoral arterial blood introduced surgically into the rodent brain. Continuous administration of iopromide during the CT acquisition produced consistent vascular contrast in the reconstructed CT images. As a result, carotid

Maxillofacial imaging

Energy Technology Data Exchange (ETDEWEB)

Larheim, T.A. [Oslo Univ. (Norway). Dept. of Maxillofacial Radiology; Westesson, P.L. [Univ. of Rochester School of Medicine and Dentistry, NY (United States). Div. of Diagnostic and Interventional Radiology

2006-07-01

Maxillofacial imaging has evolved dramatically over the past two decades with development of new cross-sectional imaging techniques. Traditional maxillofacial imaging was based on plain films and dental imaging. However, today's advanced imaging techniques with CT and MRI have only been partially implemented for maxillofacial questions. This book bridges the gap between traditional maxillofacial imaging and advanced medical imaging. We have applied CT and MRI to a variety of maxillofacial cases and these are illustrated with high-quality images and multiple planes. A comprehensive chapter on imaging anatomy is also included. This book is useful for oral and maxillofacial radiologists, oral and maxillofacial surgeons, dentists, radiologists, plastic surgeons, head and neck surgeons, and others that work with severe maxillofacial disorders. (orig.)

High-picture quality industrial CT scanner

International Nuclear Information System (INIS)

Shoji, Takao; Nishide, Akihiko; Fujii, Masashi.

1989-01-01

Industrial X-ray-CT-scanners, which provide cross-sectional images of a tested sample without destroying it, are attracting attention as a new nondestructive inspection device. In 1982, Toshiba commenced the development of industrial CT scanners, and introduced the 'TOSCANER' -3000 and-4000 series. Now, the state of the art 'TOSCANER'-20000 series of CT systems has been developed incorporating the latest computer tomography and image processing technology, such as the T9506 image processor. One of the advantages of this system is its applicability to a wide range of X-ray energy . The 'TOSCANER'-20000 series can be utilized for inspecting castings and other materials with relatively low-transparency to X-rays, as well as ceramics, composite materials and other materials with high X-ray transparency. A further feature of the new system is its high-picture quality, with a high-spatial resolution resulting from a pixel size of 0.2x0.2(mm). (author)

Neural network and its application to CT imaging

Energy Technology Data Exchange (ETDEWEB)

Nikravesh, M.; Kovscek, A.R.; Patzek, T.W. [Lawrence Berkeley National Lab., CA (United States)] [and others

1997-02-01

We present an integrated approach to imaging the progress of air displacement by spontaneous imbibition of oil into sandstone. We combine Computerized Tomography (CT) scanning and neural network image processing. The main aspects of our approach are (I) visualization of the distribution of oil and air saturation by CT, (II) interpretation of CT scans using neural networks, and (III) reconstruction of 3-D images of oil saturation from the CT scans with a neural network model. Excellent agreement between the actual images and the neural network predictions is found.

Development of comprehensive image processing technique for differential diagnosis of liver disease by using multi-modality images. Pixel-based cross-correlation method using a profile

International Nuclear Information System (INIS)

Inoue, Akira; Okura, Yasuhiko; Akiyama, Mitoshi; Ishida, Takayuki; Kawashita, Ikuo; Ito, Katsuyoshi; Matsunaga, Naofumi; Sanada, Taizo

2009-01-01

Imaging techniques such as high magnetic field imaging and multidetector-row CT have been markedly improved recently. The final image-reading systems easily produce more than a thousand diagnostic images per patient. Therefore, we developed a comprehensive cross-correlation processing technique using multi-modality images, in order to decrease the considerable time and effort involved in the interpretation of a radiogram (multi-formatted display and/or stack display method, etc). In this scheme, the criteria of an attending radiologist for the differential diagnosis of liver cyst, hemangioma of liver, hepatocellular carcinoma, and metastatic liver cancer on magnetic resonance images with various sequences and CT images with and without contrast enhancement employ a cross-correlation coefficient. Using a one-dimensional cross-correlation method, comprehensive image processing could be also adapted for various artifacts (some depending on modality imaging, and some on patients), which may be encountered at the clinical scene. This comprehensive image-processing technique could assist radiologists in the differential diagnosis of liver diseases. (author)

Squalene aspiration pneumonia : thin-section CT and histopathologic findings

International Nuclear Information System (INIS)

Lee, Jin Seong; Gong, Gyung Yub; Lim, Tae Hwan

1998-01-01

The purpose of this study was to describe the thin-section computed tomography (CT) findings and histopathologic findings of squalene aspiration pneumonia. Thin-section CT scans were obtained from nine patients with proven exogenous lipoid pneumonia resulting from aspiration of squalene (derived from shark liver oil). The condition was diagnosed by biopsy (n=3), bronchoalveolar lavage(n=4), or sputum cytology and clinical history (n=2) of squalene use was confirmed in all patients. Specimens of transbronchial lung biopsy were also reviewed and compared with thin-section CT findings. On the basis of these results, we concluded that squalene aspiration pneumonia can be reliably diagnosed by thin-section CT findings particularly when the appropriate history is known. (author). 19 refs., 3 figs

Multi-institutional MicroCT image comparison of image-guided small animal irradiators

Science.gov (United States)

Johnstone, Chris D.; Lindsay, Patricia; E Graves, Edward; Wong, Eugene; Perez, Jessica R.; Poirier, Yannick; Ben-Bouchta, Youssef; Kanesalingam, Thilakshan; Chen, Haijian; E Rubinstein, Ashley; Sheng, Ke; Bazalova-Carter, Magdalena

2017-07-01

To recommend imaging protocols and establish tolerance levels for microCT image quality assurance (QA) performed on conformal image-guided small animal irradiators. A fully automated QA software SAPA (small animal phantom analyzer) for image analysis of the commercial Shelley micro-CT MCTP 610 phantom was developed, in which quantitative analyses of CT number linearity, signal-to-noise ratio (SNR), uniformity and noise, geometric accuracy, spatial resolution by means of modulation transfer function (MTF), and CT contrast were performed. Phantom microCT scans from eleven institutions acquired with four image-guided small animal irradiator units (including the commercial PXi X-RAD SmART and Xstrahl SARRP systems) with varying parameters used for routine small animal imaging were analyzed. Multi-institutional data sets were compared using SAPA, based on which tolerance levels for each QA test were established and imaging protocols for QA were recommended. By analyzing microCT data from 11 institutions, we established image QA tolerance levels for all image quality tests. CT number linearity set to R 2  >  0.990 was acceptable in microCT data acquired at all but three institutions. Acceptable SNR  >  36 and noise levels  1.5 lp mm-1 for MTF  =  0.2) was obtained at all but four institutions due to their large image voxel size used (>0.275 mm). Ten of the eleven institutions passed the set QA tolerance for geometric accuracy (2000 HU for 30 mgI ml-1). We recommend performing imaging QA with 70 kVp, 1.5 mA, 120 s imaging time, 0.20 mm voxel size, and a frame rate of 5 fps for the PXi X-RAD SmART. For the Xstrahl SARRP, we recommend using 60 kVp, 1.0 mA, 240 s imaging time, 0.20 mm voxel size, and 6 fps. These imaging protocols should result in high quality images that pass the set tolerance levels on all systems. Average SAPA computation time for complete QA analysis for a 0.20 mm voxel, 400 slice Shelley phantom microCT data set

Non-contrast thin-section helical CT of urinary tract calculi in children

International Nuclear Information System (INIS)

Strouse, Peter J.; Bates, Gregory D.; Bloom, David A.; Goodsitt, Mitchell M.

2002-01-01

Background: Non-contrast thin-section helical CT has gained acceptance for the diagnosis of urinary tract calculi in adults, but experience with the technique in children is limited. Purpose: To evaluate the utility of non-contrast thin section helical CT for the diagnosis of urinary tract calculi in children. Materials and methods: Radiology databases at three pediatric institutions were searched to identify all pediatric patients evaluated by ''renal stone'' protocol CT scans (no oral or intravenous contrast, scans covering the entire urinary tract obtained in helical mode with narrow collimation (< 5 mm)). CT scans were reviewed for the primary finding of urinary tract calculi, for secondary signs of acute urinary tract obstruction and for evidence of alternative diagnoses. Medical records were reviewed to determine clinical presentation and to confirm the eventual diagnosis. Results: One hundred thirty-seven scans of 113 children (mean age: 11.2 years) were studied. Thirty-eight of 94 examinations (40%) performed on 82 children for acute pain and/or hematuria showed ureteral calculi. Alternative diagnoses were suggested by CT on 16 scans (17%). Twenty-eight scans were performed on 10 asymptomatic children with known calculus disease confirming renal stone burden on 21 scans (75%) and persistent ureteral calculi on 6 scans (21%). Upper tract calculi were demonstrated on 10 of 15 scans (67%) performed to evaluate for calculi in patients with known non-calculus genitourinary tract abnormalities. Conclusions: Non-contrast thin section helical CT is a useful method to diagnose urinary tract calculi in children. Radiation dose in this retrospective study may exceed the lowest possible radiation dose for diagnostic accuracy. Further research is needed to optimize CT imaging parameters, while maintaining diagnostic accuracy and minimizing radiation dose. (orig.)

CT imaging of myocardial perfusion and viability. Beyond structure and function

Energy Technology Data Exchange (ETDEWEB)

Schoepf, U. Joseph [Medical University of South Carolina, Charleston, SC (United States). Dept. of Radiology and Radiological Sciences; Bamberg, Fabian [Muenchen Univ. (Germany); Bastarrika, Gorka [Sunnybrook Health Sciences Centre, Toronto, ON (Canada). Cardiothoracic Imaging Division; Ruzsics, Balazs [Royal Liverpool and Broadgreen Univ., Liverpool (United Kingdom). Dept. of Cardiology; Vliegenthart, Rozemarijn (ed.) [University Medical Center Groningen (Netherlands). Center for Medical Imaging

2014-06-01

First publication to be devoted to the subject. Reviews an advanced, promising application in healthcare. Spans multiple medical disciplines. The rapid evolution in cardiac computed tomography during the past decade has improved spatial and temporal resolution to the extent that cardiac CT is now an accepted alternative for the non-invasive interrogation of the heart. Beyond the assessment of cardiac structure and ventricular function, recent research has identified yet another promising CT application for the comprehensive diagnosis of coronary heart disease, namely the assessment of myocardial perfusion and viability. In this book, the first to be devoted to this novel application of CT, leading experts from across the world present up-to-date information and consider future directions. After short sections outlining the state of the art in the traditional applications of CT to image structure and function, the full range of CT techniques that may be employed to evaluate the myocardial blood supply are discussed in detail. Similarly, diverse CT approaches for the assessment of myocardial viability are described, with careful consideration of the available experimental and clinical evidence and the role of quantitative imaging.

Research on Radar Cross Section Measurement Based on Near-field Imaging of Cylindrical Scanning

Directory of Open Access Journals (Sweden)

Xing Shu-guang

2015-04-01

Full Text Available A new method of Radar Cross Section (RCS measurement based on near-field imaging of cylindrical scanning surface is proposed. The method is based on the core assumption that the target consists of ideal isotropic scattered centers. Three-dimensional radar scattered images are obtained by using the proposed method, and then to obtain the RCS of the target, the scattered far field is calculated by summing the fields generated by the equivalent scattered centers. Not only three dimensional radar reflectivity images but also the RCS of targets in certain three dimensional angle areas can be obtained. Compared with circular scanning that can only obtain twodimensional radar reflectivity images and RCS results in two-dimensional angle areas, cylindrical scanning can provide more information about the scattering properties of the targets. The method has strong practicability and its validity is verified by simulations.

An experimental approach to improve the Monte Carlo modelling of offline PET/CT-imaging of positron emitters induced by scanned proton beams

International Nuclear Information System (INIS)

Bauer, J; Unholtz, D; Kurz, C; Parodi, K

2013-01-01

We report on the experimental campaign carried out at the Heidelberg Ion-Beam Therapy Center (HIT) to optimize the Monte Carlo (MC) modelling of proton-induced positron-emitter production. The presented experimental strategy constitutes a pragmatic inverse approach to overcome the known uncertainties in the modelling of positron-emitter production due to the lack of reliable cross-section data for the relevant therapeutic energy range. This work is motivated by the clinical implementation of offline PET/CT-based treatment verification at our facility. Here, the irradiation induced tissue activation in the patient is monitored shortly after the treatment delivery by means of a commercial PET/CT scanner and compared to a MC simulated activity expectation, derived under the assumption of a correct treatment delivery. At HIT, the MC particle transport and interaction code FLUKA is used for the simulation of the expected positron-emitter yield. For this particular application, the code is coupled to externally provided cross-section data of several proton-induced reactions. Studying experimentally the positron-emitting radionuclide yield in homogeneous phantoms provides access to the fundamental production channels. Therefore, five different materials have been irradiated by monoenergetic proton pencil beams at various energies and the induced β + activity subsequently acquired with a commercial full-ring PET/CT scanner. With the analysis of dynamically reconstructed PET images, we are able to determine separately the spatial distribution of different radionuclide concentrations at the starting time of the PET scan. The laterally integrated radionuclide yields in depth are used to tune the input cross-section data such that the impact of both the physical production and the imaging process on the various positron-emitter yields is reproduced. The resulting cross-section data sets allow to model the absolute level of measured β + activity induced in the investigated

An experimental approach to improve the Monte Carlo modelling of offline PET/CT-imaging of positron emitters induced by scanned proton beams

Science.gov (United States)

Bauer, J.; Unholtz, D.; Kurz, C.; Parodi, K.

2013-08-01

We report on the experimental campaign carried out at the Heidelberg Ion-Beam Therapy Center (HIT) to optimize the Monte Carlo (MC) modelling of proton-induced positron-emitter production. The presented experimental strategy constitutes a pragmatic inverse approach to overcome the known uncertainties in the modelling of positron-emitter production due to the lack of reliable cross-section data for the relevant therapeutic energy range. This work is motivated by the clinical implementation of offline PET/CT-based treatment verification at our facility. Here, the irradiation induced tissue activation in the patient is monitored shortly after the treatment delivery by means of a commercial PET/CT scanner and compared to a MC simulated activity expectation, derived under the assumption of a correct treatment delivery. At HIT, the MC particle transport and interaction code FLUKA is used for the simulation of the expected positron-emitter yield. For this particular application, the code is coupled to externally provided cross-section data of several proton-induced reactions. Studying experimentally the positron-emitting radionuclide yield in homogeneous phantoms provides access to the fundamental production channels. Therefore, five different materials have been irradiated by monoenergetic proton pencil beams at various energies and the induced β+ activity subsequently acquired with a commercial full-ring PET/CT scanner. With the analysis of dynamically reconstructed PET images, we are able to determine separately the spatial distribution of different radionuclide concentrations at the starting time of the PET scan. The laterally integrated radionuclide yields in depth are used to tune the input cross-section data such that the impact of both the physical production and the imaging process on the various positron-emitter yields is reproduced. The resulting cross-section data sets allow to model the absolute level of measured β+ activity induced in the investigated

Plastination of whole-body slices: a new aid in cross-sectional anatomy, demonstrated for thoracic organs in dogs

International Nuclear Information System (INIS)

Polgar, M.; Probst, A.; Koenig, H.E.; Sora, M.-C.

2003-01-01

Plastic-embedded, transparent serially sectioned slices from the canine thorax were compared wit cross-sections, made with the commonly used technique and computed tomograms. Three Beagles, at the age of seven months, were cut into 4 mm thick slices and plastinated with the epoxy resin Biodur E12. The area of the thorax was examined macro-scopically and scrutinized closely. Survey and magnification photographs were taken. Compared with the commonly used prepared sections the E12-slices proved to be transparent, hard, dry, odourless, resistant and show unlimited durability. Good color maintenance of the specimens makes differentiation of the organs easy. The leading of the blood vessels, nerves and other conductions of the thoracal cavity can be followed from section to section. The colorful images help to interpret CT and MRI and provide good learning aids for clinicians and students. (author)

Image quality of conventional images of dual-layer SPECTRAL CT: a phantom study.

Science.gov (United States)

van Ommen, F; Bennink, E; Vlassenbroek, A; Dankbaar, J W; Schilham, A M R; Viergever, M A; de Jong, H W A M

2018-05-10

Spectral CT using a dual layer detector offers the possibility of retrospectively introducing spectral information to conventional CT images. In theory, the dual-layer technology should not come with a dose or image quality penalty for conventional images. In this study, we evaluate the influence of a dual-layer detector (IQon Spectral CT, Philips) on the image quality of conventional CT images, by comparing these images with those of a conventional but otherwise technically comparable single-layer CT scanner (Brilliance iCT, Philips), by means of phantom experiments. For both CT scanners conventional CT images were acquired using four adult scanning protocols: i) body helical, ii) body axial, iii) head helical and iv) head axial. A CATPHAN 600 phantom was scanned to conduct an assessment of image quality metrics at equivalent (CTDI) dose levels. Noise was characterized by means of noise power spectra (NPS) and standard deviation (SD) of a uniform region, and spatial resolution was evaluated with modulation transfer functions (MTF) of a tungsten wire. In addition, contrast-to-noise ratio (CNR), image uniformity, CT number linearity, slice thickness, slice spacing, and spatial linearity were measured and evaluated. Additional measurements of CNR, resolution and noise were performed in two larger phantoms. The resolution levels at 50%, 10% and 5% MTF of the iCT and IQon showed small but significant differences up to 0.25 lp/cm for body scans, and up to 0.2 lp/cm for head scans in favor of the IQon. The iCT and IQon showed perfect CT linearity for body scans, but for head scans both scanners showed an underestimation of the CT numbers of materials with a high opacity. Slice thickness was slightly overestimated for both scanners. Slice spacing was comparable and reconstructed correctly. In addition, spatial linearity was excellent for both scanners, with a maximum error of 0.11 mm. CNR was higher on the IQon compared to the iCT for both normal and larger phantoms with

Image reconstruction design of industrial CT instrument for teaching

International Nuclear Information System (INIS)

Zou Yongning; Cai Yufang

2009-01-01

Industrial CT instrument for teaching is applied to teaching and study in field of physics and radiology major, image reconstruction is an important part of software on CT instrument. The paper expatiate on CT physical theory and first generation CT reconstruction algorithm, describe scan process of industrial CT instrument for teaching; analyze image artifact as result of displacement of rotation center, implement method of center displacement correcting, design and complete image reconstruction software, application shows that reconstructed image is very clear and qualitatively high. (authors)

Pros and cons of organ shielding for CT imaging

International Nuclear Information System (INIS)

Samei, Ehsan

2014-01-01

With the increased importance of CT radiation dose to health care providers, patients and the general public, there is an increased responsibility to minimize patient dose effectively. Bismuth shields offer a simple strategy to reduce dose to certain anterior radiosensitive organs such as breasts and eyes. However, in order to reduce organ dose they must be used properly; improper use can lead to an actual increase in the patient dose. They also create a proportional increase in image noise in the section of the body adjacent to the shield and further reduce the quantitative precision of CT numbers. In addition, shielding can degrade the overall efficiency (by an order of approximately 10%) of the imaging process, reducing the theoretical image quality that can be expected from a certain level of patient dose. However, in spite of their significant disadvantages, there are certain clinical situations and practice considerations that provide qualified justification for their continued use. (orig.)

Improving the false-negative rate of CT in acute appendicitis-Reassessment of CT images by body imaging radiologists: A blinded prospective study

International Nuclear Information System (INIS)

Poortman, Pieter; Lohle, Paul N.M.; Schoemaker, Cees M.; Cuesta, Miguel A.; Oostvogel, Henk J.M.; Lange-de Klerk, Elly S.M. de; Hamming, Jaap F.

2010-01-01

Purpose: To compare the accuracy of computed tomography (CT) analyzed by individual radiology staff members and body imaging radiologists in a non-academic teaching hospital for the diagnosis of acute appendicitis. Patients and methods: In a prospective study 199 patients with suspected acute appendicitis were examined with unenhanced CT. CT images were pre-operatively analyzed by one of the 12 members of the radiology staff. In a later stage two body imaging radiologist reassessed all CT images without knowledge of the surgical findings and without knowledge of the primary CT diagnosis. The results, independently reported, were correlated with surgical and histopathologic findings. Results: In 132 patients (66%) acute appendicitis was found at surgery, in 67 patients (34%) a normal appendix was found. The sensitivity of the primary CT analysis and of the reassessment was 76% and 88%, respectively; the specificity was 84% and 87%; the positive predictive value was 90% and 93%; the negative predictive value was 64% and 78%; and the accuracy was 78% and 87%. Conclusion: Reassessment of CT images for acute appendicitis by body imaging radiologists results in a significant improvement of sensitivity, negative predictive value and accuracy. To prevent false-negative interpretation of CT images in acute appendicitis the expertise of the attending radiologist should be considered.

Improving the false-negative rate of CT in acute appendicitis-Reassessment of CT images by body imaging radiologists: A blinded prospective study

Energy Technology Data Exchange (ETDEWEB)

Poortman, Pieter [Department of Surgery, St Elisabeth Hospital, Tilburg (Netherlands)], E-mail: ppoortman@wlz.nl; Lohle, Paul N.M. [Department of Surgery, St Elisabeth Hospital, Tilburg (Netherlands)], E-mail: plohle@elisabeth.nl; Schoemaker, Cees M. [Department of Surgery, St Elisabeth Hospital, Tilburg (Netherlands)], E-mail: mcschoemaker@elisabeth.nl; Cuesta, Miguel A. [Department of Surgery, VU Medical Centre, Amsterdam (Netherlands)], E-mail: ma.cuesta@vumc.nl; Oostvogel, Henk J.M. [Department of Surgery, St Elisabeth Hospital, Tilburg (Netherlands)], E-mail: h.oostvogel@elisabeth.nl; Lange-de Klerk, Elly S.M. de [Department of Epidemiology and Biostatistics, VU Medical Centre, Amsterdam (Netherlands)], E-mail: esm.delange@vumc.nl; Hamming, Jaap F. [Department of Surgery, Leiden University Medical Centre (Netherlands)], E-mail: j.f.hamming@lumc.nl

2010-04-15

Purpose: To compare the accuracy of computed tomography (CT) analyzed by individual radiology staff members and body imaging radiologists in a non-academic teaching hospital for the diagnosis of acute appendicitis. Patients and methods: In a prospective study 199 patients with suspected acute appendicitis were examined with unenhanced CT. CT images were pre-operatively analyzed by one of the 12 members of the radiology staff. In a later stage two body imaging radiologist reassessed all CT images without knowledge of the surgical findings and without knowledge of the primary CT diagnosis. The results, independently reported, were correlated with surgical and histopathologic findings. Results: In 132 patients (66%) acute appendicitis was found at surgery, in 67 patients (34%) a normal appendix was found. The sensitivity of the primary CT analysis and of the reassessment was 76% and 88%, respectively; the specificity was 84% and 87%; the positive predictive value was 90% and 93%; the negative predictive value was 64% and 78%; and the accuracy was 78% and 87%. Conclusion: Reassessment of CT images for acute appendicitis by body imaging radiologists results in a significant improvement of sensitivity, negative predictive value and accuracy. To prevent false-negative interpretation of CT images in acute appendicitis the expertise of the attending radiologist should be considered.

Image-guided stereotactic surgery using ultrasonography and reconstructive three-dimensional CT-imaging system

International Nuclear Information System (INIS)

Kawamura, Hirotsune; Iseki, Hiroshi; Umezawa, Yoshihiro

1991-01-01

A new simulation and navigation system utilizing three-dimensional CT images has been developed for image-guided stereotactic surgery. Preoperative CT images are not always useful in predicting the intraoperative location of lesions, for cerebral lesions are easily displaced or distorted by gravity, brain retraction, and/or CSF aspiration during operative procedure. This new system, however, has the advantage that the intraoperative locations of intracranial lesions or the anatomical structures of the brain can be precisely confirmed during stereotactic surgery. Serial CT images were obtained from a patient whose head had been fixed to the ISEKI CT-guided stereotactic frame. The data of serial CT images were saved on a floppy disc and then transferred to the work station (IRIS) using the off line. In order to find the best approach angle for ultrasound-guided stereotactic surgery, three-dimenstional CT images were reconstructed using the work station. The site of the craniotomy or the angle of the trajectory of the ultrasound probe was measured preoperatively based on the three-dimensional CT images. Then, in the operating room, the patient's head was fixed to the ISEKI frame with the subframe at the same position as before according to the measurement of the CT images. In a case of cystic glioma, the predicable ultrasonograms from three-dimensional reconstructive CT images were ascertained to correspond well to the actual ultrasound images during ultrasound-guided stereotactic surgery. Therefore, the new simulation and navigation system can be judged to be a powerful operative supporting modality for correcting the locations of cerebral lesions; it allows one to perform stereotactic surgery more accurately and less invasively. (author)

WE-G-207-05: Relationship Between CT Image Quality, Segmentation Performance, and Quantitative Image Feature Analysis

Energy Technology Data Exchange (ETDEWEB)

Lee, J; Nishikawa, R [University of Pittsburgh, Pittsburgh, PA (United States); Reiser, I [The University of Chicago, Chicago, IL (United States); Boone, J [UC Davis Medical Center, Sacramento, CA (United States)

2015-06-15

Purpose: Segmentation quality can affect quantitative image feature analysis. The objective of this study is to examine the relationship between computed tomography (CT) image quality, segmentation performance, and quantitative image feature analysis. Methods: A total of 90 pathology proven breast lesions in 87 dedicated breast CT images were considered. An iterative image reconstruction (IIR) algorithm was used to obtain CT images with different quality. With different combinations of 4 variables in the algorithm, this study obtained a total of 28 different qualities of CT images. Two imaging tasks/objectives were considered: 1) segmentation and 2) classification of the lesion as benign or malignant. Twenty-three image features were extracted after segmentation using a semi-automated algorithm and 5 of them were selected via a feature selection technique. Logistic regression was trained and tested using leave-one-out-cross-validation and its area under the ROC curve (AUC) was recorded. The standard deviation of a homogeneous portion and the gradient of a parenchymal portion of an example breast were used as an estimate of image noise and sharpness. The DICE coefficient was computed using a radiologist’s drawing on the lesion. Mean DICE and AUC were used as performance metrics for each of the 28 reconstructions. The relationship between segmentation and classification performance under different reconstructions were compared. Distributions (median, 95% confidence interval) of DICE and AUC for each reconstruction were also compared. Results: Moderate correlation (Pearson’s rho = 0.43, p-value = 0.02) between DICE and AUC values was found. However, the variation between DICE and AUC values for each reconstruction increased as the image sharpness increased. There was a combination of IIR parameters that resulted in the best segmentation with the worst classification performance. Conclusion: There are certain images that yield better segmentation or classification

Research of ART method in CT image reconstruction

International Nuclear Information System (INIS)

Li Zhipeng; Cong Peng; Wu Haifeng

2005-01-01

This paper studied Algebraic Reconstruction Technique (ART) in CT image reconstruction. Discussed the ray number influence on image quality. And the adopting of smooth method got high quality CT image. (authors)

Automatic anatomy recognition in whole-body PET/CT images

Energy Technology Data Exchange (ETDEWEB)

Wang, Huiqian [College of Optoelectronic Engineering, Chongqing University, Chongqing 400044, China and Medical Image Processing Group Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States); Udupa, Jayaram K., E-mail: jay@mail.med.upenn.edu; Odhner, Dewey; Tong, Yubing; Torigian, Drew A. [Medical Image Processing Group Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States); Zhao, Liming [Medical Image Processing Group Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104 and Research Center of Intelligent System and Robotics, Chongqing University of Posts and Telecommunications, Chongqing 400065 (China)

2016-01-15

Purpose: Whole-body positron emission tomography/computed tomography (PET/CT) has become a standard method of imaging patients with various disease conditions, especially cancer. Body-wide accurate quantification of disease burden in PET/CT images is important for characterizing lesions, staging disease, prognosticating patient outcome, planning treatment, and evaluating disease response to therapeutic interventions. However, body-wide anatomy recognition in PET/CT is a critical first step for accurately and automatically quantifying disease body-wide, body-region-wise, and organwise. This latter process, however, has remained a challenge due to the lower quality of the anatomic information portrayed in the CT component of this imaging modality and the paucity of anatomic details in the PET component. In this paper, the authors demonstrate the adaptation of a recently developed automatic anatomy recognition (AAR) methodology [Udupa et al., “Body-wide hierarchical fuzzy modeling, recognition, and delineation of anatomy in medical images,” Med. Image Anal. 18, 752–771 (2014)] to PET/CT images. Their goal was to test what level of object localization accuracy can be achieved on PET/CT compared to that achieved on diagnostic CT images. Methods: The authors advance the AAR approach in this work in three fronts: (i) from body-region-wise treatment in the work of Udupa et al. to whole body; (ii) from the use of image intensity in optimal object recognition in the work of Udupa et al. to intensity plus object-specific texture properties, and (iii) from the intramodality model-building-recognition strategy to the intermodality approach. The whole-body approach allows consideration of relationships among objects in different body regions, which was previously not possible. Consideration of object texture allows generalizing the previous optimal threshold-based fuzzy model recognition method from intensity images to any derived fuzzy membership image, and in the process

Automatic anatomy recognition in whole-body PET/CT images

International Nuclear Information System (INIS)

Wang, Huiqian; Udupa, Jayaram K.; Odhner, Dewey; Tong, Yubing; Torigian, Drew A.; Zhao, Liming

2016-01-01

Purpose: Whole-body positron emission tomography/computed tomography (PET/CT) has become a standard method of imaging patients with various disease conditions, especially cancer. Body-wide accurate quantification of disease burden in PET/CT images is important for characterizing lesions, staging disease, prognosticating patient outcome, planning treatment, and evaluating disease response to therapeutic interventions. However, body-wide anatomy recognition in PET/CT is a critical first step for accurately and automatically quantifying disease body-wide, body-region-wise, and organwise. This latter process, however, has remained a challenge due to the lower quality of the anatomic information portrayed in the CT component of this imaging modality and the paucity of anatomic details in the PET component. In this paper, the authors demonstrate the adaptation of a recently developed automatic anatomy recognition (AAR) methodology [Udupa et al., “Body-wide hierarchical fuzzy modeling, recognition, and delineation of anatomy in medical images,” Med. Image Anal. 18, 752–771 (2014)] to PET/CT images. Their goal was to test what level of object localization accuracy can be achieved on PET/CT compared to that achieved on diagnostic CT images. Methods: The authors advance the AAR approach in this work in three fronts: (i) from body-region-wise treatment in the work of Udupa et al. to whole body; (ii) from the use of image intensity in optimal object recognition in the work of Udupa et al. to intensity plus object-specific texture properties, and (iii) from the intramodality model-building-recognition strategy to the intermodality approach. The whole-body approach allows consideration of relationships among objects in different body regions, which was previously not possible. Consideration of object texture allows generalizing the previous optimal threshold-based fuzzy model recognition method from intensity images to any derived fuzzy membership image, and in the process

Evaluation of pulmonary emphysema by the fused image of CT image and ventilation SPECT image

International Nuclear Information System (INIS)

Okuda, Ituko; Maruno, Hiromasa; Mori, Kazuaki; Kohno, Tadashi; Kokubo, Takashi

2007-01-01

We evaluated pulmonary emphysema using a diagnostic device that could obtain a CT image, a ventilation single photon emission computed tomography (SPECT) image and a lung perfusion SPECT image in one examination. The fused image made from the CT image and SPECT image had very little position gap between images, and the precision was high. From the fused image, we were able to detect the areas in which emphysematous change was the most marked in the CT image, while the accumulation decrease was most remarkable in the ventilation SPECT image. Thus it was possible to obtain an accurate status of pulmonary emphysema, and our method was regarded as a useful technique. (author)

Comparison of bone-implant contact and bone-implant volume between 2D-histological sections and 3D-SRµCT slices

Directory of Open Access Journals (Sweden)

R Bernhardt

2012-04-01

Full Text Available Histological imaging is still considered the gold standard for analysing bone formation around metallic implants. Generally, a limited number of histological sections per sample are used for the approximation of mean values of peri-implant bone formation. In this study we compared statistically the results of bone-implant contact (BIC and bone-implant volume (BIV obtained by histological sections, with those obtained by X-ray absorption images from synchrotron radiation micro-computed tomography (SRµCT using osseointegrated screw-shaped implants from a mini-pig study. Comparing the BIC results of 3-4 histological sections per implant sample with the appropriate 3-4 SRµCT slices showed a non-significant difference of 1.9 % (p = 0.703. The contact area assessed by the whole 3D information from the SRµCT measurement in comparison to the histomorphometric results showed a non-significant difference in BIC of 4.9 % (p = 0.171. The amount of the bone-implant volume in the histological sections and the appropriate SRµCT slices showed a non-significant difference by only 1.4 % (p = 0.736 and also remains non-significant with 2.6 % (p = 0.323 using the volumetric SRµCT information. We conclude that for a clinical evaluation of implant osseointegration with histological imaging at least 3-4 sections per sample are sufficient to represent the BIC or BIV for a sample. Due to the fact that in this study we have found a significant intra-sample variation in BIC of up to ± 35 % the selection of only one or two histological sections per sample may strongly influence the determined BIC.

Three-dimensional multislice CT imaging of otitis media

International Nuclear Information System (INIS)

Suzuki, Miyako; Yoshikawa, Hiroshi; Hosokawa, Akira; Furukawa, Tomoyasu; Ichikawa, Ginichiro; Wada, Akihiro; Ando, Ichiro

2002-01-01

In recent years, the multislice CT system has come into practical use that enables table movement of half mm, resulting in a significant improvement in resolution. The use of this CT system enables to depict the entire auditory ossicles, including the stapes. 3D reconstruction was performed using helical CT data in 5 patients with chronic otitis media and 5 patients with cholesteatoma. An Aquilion Multi (Toshiba) multislice helical CT scanner and a Xtension (Toshiba) image workstation were used in this study. We demonstrated the 3D display with axial, coronal and sagittal images. Compared with the normal ears, it was necessary to set a higher threshold for the affected ears. It is important to select suitable threshold for demonstration of 3D images optimally. Bone destruction of the stapes was confirmed at surgery in 2 ears. The stapes was observed at 3D-CT imaging in other 18 ears. It was found that the 3D images of the ossicular destruction in ears with cholesteatoma were consistent with surgical findings. It is therefore concluded that 3D imaging of the middle ear using a multislice CT scanner is clinically useful. (author)

Three-dimensional multislice CT imaging of otitis media

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Suzuki, Miyako [Yanagibasi Hospital, Tokyo (Japan); Yoshikawa, Hiroshi; Hosokawa, Akira; Furukawa, Tomoyasu; Ichikawa, Ginichiro [Juntendo Univ., Tokyo (Japan). School of Medicine; Wada, Akihiro; Ando, Ichiro [Juntendo Univ., Chiba (Japan). Urayasu Hospital

2002-07-01

In recent years, the multislice CT system has come into practical use that enables table movement of half mm, resulting in a significant improvement in resolution. The use of this CT system enables to depict the entire auditory ossicles, including the stapes. 3D reconstruction was performed using helical CT data in 5 patients with chronic otitis media and 5 patients with cholesteatoma. An Aquilion Multi (Toshiba) multislice helical CT scanner and a Xtension (Toshiba) image workstation were used in this study. We demonstrated the 3D display with axial, coronal and sagittal images. Compared with the normal ears, it was necessary to set a higher threshold for the affected ears. It is important to select suitable threshold for demonstration of 3D images optimally. Bone destruction of the stapes was confirmed at surgery in 2 ears. The stapes was observed at 3D-CT imaging in other 18 ears. It was found that the 3D images of the ossicular destruction in ears with cholesteatoma were consistent with surgical findings. It is therefore concluded that 3D imaging of the middle ear using a multislice CT scanner is clinically useful. (author)

SU-F-I-08: CT Image Ring Artifact Reduction Based On Prior Image

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Yuan, C; Qi, H; Chen, Z; Wu, S; Xu, Y; Zhou, L [Southern Medical University, Guangzhou, Guangdong (China)

2016-06-15

Purpose: In computed tomography (CT) system, CT images with ring artifacts will be reconstructed when some adjacent bins of detector don’t work. The ring artifacts severely degrade CT image quality. We present a useful CT ring artifacts reduction based on projection data correction, aiming at estimating the missing data of projection data accurately, thus removing the ring artifacts of CT images. Methods: The method consists of ten steps: 1) Identification of abnormal pixel line in projection sinogram; 2) Linear interpolation within the pixel line of projection sinogram; 3) FBP reconstruction using interpolated projection data; 4) Filtering FBP image using mean filter; 5) Forwarding projection of filtered FBP image; 6) Subtraction forwarded projection from original projection; 7) Linear interpolation of abnormal pixel line area in the subtraction projection; 8) Adding the interpolated subtraction projection on the forwarded projection; 9) FBP reconstruction using corrected projection data; 10) Return to step 4 until the pre-set iteration number is reached. The method is validated on simulated and real data to restore missing projection data and reconstruct ring artifact-free CT images. Results: We have studied impact of amount of dead bins of CT detector on the accuracy of missing data estimation in projection sinogram. For the simulated case with a resolution of 256 by 256 Shepp-Logan phantom, three iterations are sufficient to restore projection data and reconstruct ring artifact-free images when the dead bins rating is under 30%. The dead-bin-induced artifacts are substantially reduced. More iteration number is needed to reconstruct satisfactory images while the rating of dead bins increases. Similar results were found for a real head phantom case. Conclusion: A practical CT image ring artifact correction scheme based on projection data is developed. This method can produce ring artifact-free CT images feasibly and effectively.

SU-F-I-08: CT Image Ring Artifact Reduction Based On Prior Image

International Nuclear Information System (INIS)

Yuan, C; Qi, H; Chen, Z; Wu, S; Xu, Y; Zhou, L

2016-01-01

Purpose: In computed tomography (CT) system, CT images with ring artifacts will be reconstructed when some adjacent bins of detector don’t work. The ring artifacts severely degrade CT image quality. We present a useful CT ring artifacts reduction based on projection data correction, aiming at estimating the missing data of projection data accurately, thus removing the ring artifacts of CT images. Methods: The method consists of ten steps: 1) Identification of abnormal pixel line in projection sinogram; 2) Linear interpolation within the pixel line of projection sinogram; 3) FBP reconstruction using interpolated projection data; 4) Filtering FBP image using mean filter; 5) Forwarding projection of filtered FBP image; 6) Subtraction forwarded projection from original projection; 7) Linear interpolation of abnormal pixel line area in the subtraction projection; 8) Adding the interpolated subtraction projection on the forwarded projection; 9) FBP reconstruction using corrected projection data; 10) Return to step 4 until the pre-set iteration number is reached. The method is validated on simulated and real data to restore missing projection data and reconstruct ring artifact-free CT images. Results: We have studied impact of amount of dead bins of CT detector on the accuracy of missing data estimation in projection sinogram. For the simulated case with a resolution of 256 by 256 Shepp-Logan phantom, three iterations are sufficient to restore projection data and reconstruct ring artifact-free images when the dead bins rating is under 30%. The dead-bin-induced artifacts are substantially reduced. More iteration number is needed to reconstruct satisfactory images while the rating of dead bins increases. Similar results were found for a real head phantom case. Conclusion: A practical CT image ring artifact correction scheme based on projection data is developed. This method can produce ring artifact-free CT images feasibly and effectively.

Skeletal scintigraphy and SPECT/CT in orthopedic imaging

International Nuclear Information System (INIS)

Klaeser, B.; Walter, M.; Krause, T.

2011-01-01

Multi-modality imaging with SPECT-CT in orthopaedics combines the excellent sensitivity of scintigraphy with the morphological information of CT as a key for specific interpretation of findings in bone scans. The result is an imaging modality with the clear potential to prove of value even in a competitive setting dominated by MRI, and to significantly add to diagnostic imaging in orthopaedics. SPECT-CT is of great value in the diagnostic evaluation after fractures, and - in contrast to MRI - it is well suited for imaging in patients with osteosyntheses and metallic implants. In sports medicine, SPECT-CT allows for a sensitive and specific detection of osseous stress reactions before morphological changes become detectable by CT or MRI. In patients with osseous pain syndromes, actively evolving degenerative changes as a cause of pain can be identified and accurately localized. Further, particularly prospective diagnostic studies providing comparative data are needed to strengthen the position of nuclear imaging in orthopaedics and sports medicine and to help implementing SPECT/CT in diagnostic algorithms. (orig.)

Utilization of CT images for the quantification of FDG uptake

International Nuclear Information System (INIS)

Karidioula, I.; De Freitas, D.; Cachin, F.; Geissler, B.; Jullien, Ph.; Maublant, J.

2006-01-01

The aim of this study was to evaluate an automatic method based on a computed tomography (CT) derived region of interest (ROI) to quantify the mean standardized uptake value (SUVm) of 18 F-fluoro-deoxy-glucose (FDG) in pulmonary lesions detected by positron emission tomography (PET). A total of 164 pairs of slices were selected in a series of PET/CT studies performed in 26 patients presenting lung tumours of various forms and complexities. On each matched CT slice, a ROI was obtained by growth-region segmentation starting from a pixel contained in the tumour. The obtained ROI was then applied to the PET image to calculate SUVm. Results were compared with the conventional manual method using a geometric ROI positioned directly on the PET lesion. The automatic delineation of the tumour from the CT image was successful in 136 sections (83%). The SUVm calculated by the manual and automatic method were respectively (mean±standard deviation) 5.05±2.39 and 6.70±3.18 (p<0.05). The ROI size (in number of pixels) was respectively 28±23 and 21±17 (p<0.05). The variability of the automatic method was 0% versus 20% for the manual method. SUV of FDG in PET/CT can be calculated with an excellent reproducibility by using the CT-derived limits of the lesion

CT and MR image fusion using two different methods after prostate brachytherapy: impact on post-implant dosimetric assessment

International Nuclear Information System (INIS)

Servois, V.; El Khoury, C.; Lantoine, A.; Ollivier, L.; Neuenschwander, S.; Chauveinc, L.; Cosset, J.M.; Flam, T.; Rosenwald, J.C.

2003-01-01

To study different methods of CT and MR images fusion in patient treated by brachytherapy for localized prostate cancer. To compare the results of the dosimetric study realized on CT slices and images fusion. Fourteen cases of patients treated by 1125 were retrospectively studied. The CT examinations were realized with continuous section of 5 mm thickness, and MR images were obtained with a surface coil with contiguous section of 3 mm thickness. For the images fusion process, only the T2 weighted MR sequence was used. Two processes of images fusion were realized for each patient, using as reference marks the bones of the pelvis and the implanted seeds. A quantitative and qualitative appreciation was made by the operators, for each patient and both methods of images fusion. The dosimetric study obtained by a dedicated software was realized on CT images and all types of images fusion. The usual dosimetric indexes (D90, V 100 and V 150) were compared for each type of image. The quantitative results given by the software of images fusion showed a superior accuracy to the one obtained by the pelvic bony reference marks. Conversely, qualitative and quantitative results obtained by the operators showed a better accuracy of the images fusion based on iodine seeds. For two patients out of three presenting a D90 inferior to 145 Gy on CT examination, the D90 was superior to this norm when the dosimetry was based on images fusion, whatever the method used. The images fusion method based on implanted seed matching seems to be more precise than the one using bony reference marks. The dosimetric study realized on images fusion could allow to rectify possible errors, mainly due to difficulties in surrounding prostate contour delimitation on CT images. (authors)

Dose performance and image quality: Dual source CT versus single source CT in cardiac CT angiography

International Nuclear Information System (INIS)

Wang Min; Qi Hengtao; Wang Ximing; Wang Tao; Chen, Jiu-Hong; Liu Cheng

2009-01-01

Objective: To evaluate dose performance and image quality of 64-slice dual source CT (DSCT) in comparison to 64-slice single source CT (SSCT) in cardiac CT angiography (CTA). Methods: 100 patients examined by DSCT and 60 patients scanned by SSCT were included in this study. Objective indices such as image noise, contrast-to-noise ratio and signal-to-noise ratio were analyzed. Subjective image quality was assessed by two cardiovascular radiologists in consensus using a four-point scale (1 = excellent to 4 = not acceptable). Estimation of effective dose was performed on the basis of dose length product (DLP). Results: At low heart rates ( 0.05), but, at high heart rates (>70 bpm), DSCT provided robust image quality (P 70 bpm), DSCT is able to provide robust diagnostic image quality at doses far below that of SSCT.

Cone beam CT findings of retromolar canals: Report of cases and literature review

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Han, Sang Sun [Dept. of Dental Hygiene, Eulji University, Seongnam (Korea, Republic of); Park, Chang Seo [Dept. of Oral and Maxillofacial Radiology, College of Dentistry, Yonsei University, Seoul (Korea, Republic of)

2013-12-15

A retromolar canal is an anatomical variation in the mandible. As it includes the neurovascular bundle, local anesthetic insufficiency can occur, and an injury of the retromolar canal during dental surgery in the mandible may result in excessive bleeding, paresthesia, and traumatic neuroma. Using imaging analysis software, we evaluated the cone-beam computed tomography (CT) images of two Korean patients who presented with retromolar canals. Retromolar canals were detectable on the sagittal and cross-sectional images of cone-beam CT, but not on the panoramic radiographs of the patients. Therefore, the clinician should pay particular attention to the identification of retromolar canals by preoperative radiographic examination, and additional cone beam CT scanning would be recommended.

Cone beam CT findings of retromolar canals: Report of cases and literature review

International Nuclear Information System (INIS)

Han, Sang Sun; Park, Chang Seo

2013-01-01

A retromolar canal is an anatomical variation in the mandible. As it includes the neurovascular bundle, local anesthetic insufficiency can occur, and an injury of the retromolar canal during dental surgery in the mandible may result in excessive bleeding, paresthesia, and traumatic neuroma. Using imaging analysis software, we evaluated the cone-beam computed tomography (CT) images of two Korean patients who presented with retromolar canals. Retromolar canals were detectable on the sagittal and cross-sectional images of cone-beam CT, but not on the panoramic radiographs of the patients. Therefore, the clinician should pay particular attention to the identification of retromolar canals by preoperative radiographic examination, and additional cone beam CT scanning would be recommended.

Photoionization cross section by Stieltjes imaging applied to coupled cluster Lanczos pseudo-spectra

Science.gov (United States)

Cukras, Janusz; Coriani, Sonia; Decleva, Piero; Christiansen, Ove; Norman, Patrick

2013-09-01

A recently implemented asymmetric Lanczos algorithm for computing (complex) linear response functions within the coupled cluster singles (CCS), coupled cluster singles and iterative approximate doubles (CC2), and coupled cluster singles and doubles (CCSD) is coupled to a Stieltjes imaging technique in order to describe the photoionization cross section of atoms and molecules, in the spirit of a similar procedure recently proposed by Averbukh and co-workers within the Algebraic Diagrammatic Construction approach. Pilot results are reported for the atoms He, Ne, and Ar and for the molecules H2, H2O, NH3, HF, CO, and CO2.

Photoionization cross section by Stieltjes imaging applied to coupled cluster Lanczos pseudo-spectra

International Nuclear Information System (INIS)

Cukras, Janusz; Coriani, Sonia; Decleva, Piero; Christiansen, Ove; Norman, Patrick

2013-01-01

A recently implemented asymmetric Lanczos algorithm for computing (complex) linear response functions within the coupled cluster singles (CCS), coupled cluster singles and iterative approximate doubles (CC2), and coupled cluster singles and doubles (CCSD) is coupled to a Stieltjes imaging technique in order to describe the photoionization cross section of atoms and molecules, in the spirit of a similar procedure recently proposed by Averbukh and co-workers within the Algebraic Diagrammatic Construction approach. Pilot results are reported for the atoms He, Ne, and Ar and for the molecules H 2 , H 2 O, NH 3 , HF, CO, and CO 2

Skin Diseases: Cross-section of human skin

Science.gov (United States)

Skip Navigation Bar Home Current Issue Past Issues Skin Diseases Cross-section of human skin Past Issues / Fall 2008 Table of Contents For ... Logical Images, Inc. I n the areas of skin health and skin diseases, the NIH's National Institute ...

Quantitative Analysis of Micro-CT Imaging and Histopathological Signatures of Experimental Arthritis in Rats

Directory of Open Access Journals (Sweden)

Matthew D. Silva

2004-10-01

Full Text Available Micro-computed tomographic (micro-CT imaging provides a unique opportunity to capture 3-D architectural information in bone samples. In this study of pathological joint changes in a rat model of adjuvant-induced arthritis (AA, quantitative analysis of bone volume and roughness were performed by micro-CT imaging and compared with histopathology methods and paw swelling measurement. Micro-CT imaging of excised rat hind paws (n = 10 stored in formalin consisted of approximately 600 30-μm slices acquired on a 512 × 512 image matrix with isotropic resolution. Following imaging, the joints were scored from H&E stained sections for cartilage/bone erosion, pannus development, inflammation, and synovial hyperplasia. From micro-CT images, quantitative analysis of absolute bone volumes and bone roughness was performed. Bone erosion in the rat AA model is substantial, leading to a significant decline in tarsal volume (27%. The result of the custom bone roughness measurement indicated a 55% increase in surface roughness. Histological and paw volume analyses also demonstrated severe arthritic disease as compared to controls. Statistical analyses indicate correlations among bone volume, roughness, histology, and paw volume. These data demonstrate that the destructive progression of disease in a rat AA model can be quantified using 3-D micro-CT image analysis, which allows assessment of arthritic disease status and efficacy of experimental therapeutic agents.

Thin-section CT of Cushing's disease

International Nuclear Information System (INIS)

Takahashi, Tatsuo; Kuwayama, Akio; Katoh, Tetsuo; Ichihara, Kaoru; Kageyama, Naoki; Nakamura, Koji.

1983-01-01

Using 1.5 mm contiguous sections with a GE CT/T 8800 scanner, we investigated the sellar regions of 22 cases of Cushing's diseases which had been diagnosed endocrinologically. Each sellar turcica was normal in size, and in only 5 cases were there significant findings on 2 mm-thick sellar-floor polytomography. Nine tumors appeared as regions of a hypodense area, and three tumors were diagnosed by indirect signs, for example, stalk deviation and diaphragmatic plane asymmetry. The other 10 cases, especially those previously operated on or irradiated, were diagnosed as falsely positive or negative. Because it is best of the microadenomas appear hypodense within the strongly contrast-enhanced anterior pituitary glands, it is better for scans to be obtained immediately after rapid intravenous contrast infusion. Hypodense areas of microadenomas are best demonstrated on direct coronal scans or reversed scans of 1.5 mm-thickness thin-slice sections. By these methods, microadenomas, if they are over 5-6 mm in diameter, can appear as hypodense. Sellar floor findings by means of thin-section CT were more sensitive than those of polytomography and had more advantages in local diagnosis. If the tumor were over 4 mm in diameter, local changes in the sellar floor could be demonstrated by thin-section CT, but by polytomography no changes in the sellar floor could be demonstrated until the tumor size reached 6 mm. (author)

Fast GPU-based Monte Carlo code for SPECT/CT reconstructions generates improved 177Lu images.

Science.gov (United States)

Rydén, T; Heydorn Lagerlöf, J; Hemmingsson, J; Marin, I; Svensson, J; Båth, M; Gjertsson, P; Bernhardt, P

2018-01-04

Full Monte Carlo (MC)-based SPECT reconstructions have a strong potential for correcting for image degrading factors, but the reconstruction times are long. The objective of this study was to develop a highly parallel Monte Carlo code for fast, ordered subset expectation maximum (OSEM) reconstructions of SPECT/CT images. The MC code was written in the Compute Unified Device Architecture language for a computer with four graphics processing units (GPUs) (GeForce GTX Titan X, Nvidia, USA). This enabled simulations of parallel photon emissions from the voxels matrix (128 3 or 256 3 ). Each computed tomography (CT) number was converted to attenuation coefficients for photo absorption, coherent scattering, and incoherent scattering. For photon scattering, the deflection angle was determined by the differential scattering cross sections. An angular response function was developed and used to model the accepted angles for photon interaction with the crystal, and a detector scattering kernel was used for modeling the photon scattering in the detector. Predefined energy and spatial resolution kernels for the crystal were used. The MC code was implemented in the OSEM reconstruction of clinical and phantom 177 Lu SPECT/CT images. The Jaszczak image quality phantom was used to evaluate the performance of the MC reconstruction in comparison with attenuated corrected (AC) OSEM reconstructions and attenuated corrected OSEM reconstructions with resolution recovery corrections (RRC). The performance of the MC code was 3200 million photons/s. The required number of photons emitted per voxel to obtain a sufficiently low noise level in the simulated image was 200 for a 128 3 voxel matrix. With this number of emitted photons/voxel, the MC-based OSEM reconstruction with ten subsets was performed within 20 s/iteration. The images converged after around six iterations. Therefore, the reconstruction time was around 3 min. The activity recovery for the spheres in the Jaszczak phantom was

Three-dimensional modeling and simulation of asphalt concrete mixtures based on X-ray CT microstructure images

Directory of Open Access Journals (Sweden)

Hainian Wang

2014-02-01

Full Text Available X-ray CT (computed tomography was used to scan asphalt mixture specimen to obtain high resolution continuous cross-section images and the meso-structure. According to the theory of three-dimensional (3D reconstruction, the 3D reconstruction algorithm was investigated in this paper. The key to the reconstruction technique is the acquisition of the voxel positions and the relationship between the pixel element and node. Three-dimensional numerical model of asphalt mixture specimen was created by a self-developed program. A splitting test was conducted to predict the stress distributions of the asphalt mixture and verify the rationality of the 3D model.

Correlative Imaging in a Patient with Cystic Thymoma: CT, MR and PET/CT Comparison

International Nuclear Information System (INIS)

Romeo, Valeria; Esposito, Alfredo; Maurea, Simone; Camera, Luigi; Mainenti, Pier Paolo; Palmieri, Giovannella; Buonerba, Carlo; Salvatore, Marco

2015-01-01

Cystic thymoma is a rare variant of thymic neoplasm characterized by almost complete cystic degeneration with mixed internal structure. We describe a case of a 60 year-old woman with a cystic thymoma studied with advanced tomographic imaging stydies. CT, MRI and PET/CT with 18 F-FDG were performed; volumetric CT and MRI images provided better anatomic evaluation for pre-operative assessment, while PET/CT was helpful for lesion characterization based on 18 F-FDG uptake. Although imaging studies are mandatory for pre-operative evaluation of cystic thymoma, final diagnosis still remains surgical. A 60-year-old woman with recent chest pain and no history of previous disease was admitted to our departement to investigate the result of a previous chest X-ray that showed bilateral mediastinal enlargement; for this purpose, enhanced chest CT scan was performed using a 64-rows scanner (Toshiba, Aquilion 64, Japan) before and after intravenous bolus administration of iodinated non ionic contrast agent; CT images demonstrated the presence of a large mediastinal mass (11×8 cm) located in the anterior mediastinum who extended from the anonymous vein to the cardio-phrenic space, compressing the left atrium and causing medium lobe atelectasis; bilateral pleural effusion was also present. In conclusion, correlative imaging plays a foundamental role for the diagnostic evaluation of patient with cystic thymoma. In particular, volumetric CT and MRI studies can provide better anatomic informations regarding internal structure and local tumor spread for pre-operative assessment. Conversely, metabolic imaging using 18 F-FDG PET/CT is helpful for lesion characterization differentiating benign from malignant lesion on the basis of intense tracer uptake. The role of PET/MRI is still under investigation. However, final diagnosis still remains surgical even though imaging studies are mandatory for pre-operative patient management

Dynamic CT myocardial perfusion imaging

International Nuclear Information System (INIS)

Caruso, Damiano; Eid, Marwen; Schoepf, U. Joseph; Jin, Kwang Nam; Varga-Szemes, Akos; Tesche, Christian; Mangold, Stefanie

2016-01-01

Highlights: • CT myocardial perfusion provides functional assessment of the myocardium. • CCTA is limited in determining the hemodynamic significance of coronary stenosis. • CT-MPI can accurately detect hemodynamically significant coronary artery stenosis. - Abstract: Non-invasive cardiac imaging has rapidly evolved during the last decade due to advancements in CT based technologies. Coronary CT angiography has been shown to reliably assess coronary anatomy and detect high risk coronary artery disease. However, this technique is limited to anatomical assessment, thus non-invasive techniques for functional assessment of the heart are necessary. CT myocardial perfusion is a new CT based technique that provides functional assessment of the myocardium and allows for a comprehensive assessment of coronary artery disease with a single modality when combined with CTA. This review aims to discuss dynamic CT myocardial perfusion as a new technique in the assessment of CAD.

Dynamic CT myocardial perfusion imaging

Energy Technology Data Exchange (ETDEWEB)

Caruso, Damiano [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiological Sciences, Oncological and Pathological Sciences, University of Rome “Sapienza”, Latina (Italy); Eid, Marwen [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Schoepf, U. Joseph, E-mail: schoepf@musc.edu [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC (United States); Jin, Kwang Nam [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiology, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul (Korea, Republic of); Varga-Szemes, Akos [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Tesche, Christian [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Cardiology and Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich (Germany); Mangold, Stefanie [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Tuebingen (Germany); and others

2016-10-15

Highlights: • CT myocardial perfusion provides functional assessment of the myocardium. • CCTA is limited in determining the hemodynamic significance of coronary stenosis. • CT-MPI can accurately detect hemodynamically significant coronary artery stenosis. - Abstract: Non-invasive cardiac imaging has rapidly evolved during the last decade due to advancements in CT based technologies. Coronary CT angiography has been shown to reliably assess coronary anatomy and detect high risk coronary artery disease. However, this technique is limited to anatomical assessment, thus non-invasive techniques for functional assessment of the heart are necessary. CT myocardial perfusion is a new CT based technique that provides functional assessment of the myocardium and allows for a comprehensive assessment of coronary artery disease with a single modality when combined with CTA. This review aims to discuss dynamic CT myocardial perfusion as a new technique in the assessment of CAD.

Skeletal scintigraphy and SPECT/CT in orthopedic imaging; Knochenszintigrafie und SPECT/CT bei orthopaedischen Fragestellungen

Energy Technology Data Exchange (ETDEWEB)

Klaeser, B.; Walter, M.; Krause, T. [Inselspital Bern (Switzerland). Universitaetsklinik fuer Nuklearmedizin

2011-03-15

Multi-modality imaging with SPECT-CT in orthopaedics combines the excellent sensitivity of scintigraphy with the morphological information of CT as a key for specific interpretation of findings in bone scans. The result is an imaging modality with the clear potential to prove of value even in a competitive setting dominated by MRI, and to significantly add to diagnostic imaging in orthopaedics. SPECT-CT is of great value in the diagnostic evaluation after fractures, and - in contrast to MRI - it is well suited for imaging in patients with osteosyntheses and metallic implants. In sports medicine, SPECT-CT allows for a sensitive and specific detection of osseous stress reactions before morphological changes become detectable by CT or MRI. In patients with osseous pain syndromes, actively evolving degenerative changes as a cause of pain can be identified and accurately localized. Further, particularly prospective diagnostic studies providing comparative data are needed to strengthen the position of nuclear imaging in orthopaedics and sports medicine and to help implementing SPECT/CT in diagnostic algorithms. (orig.)

Geometric modelling of a make mandible utilising CT imaging

International Nuclear Information System (INIS)

Baker, N.; Basu, A.; McLean, A.G.; Jamieson, D.; Jonkman, M.

1996-01-01

Full text: The mandible is one of the most important and frequently used bones in the human body. It is responsible for basic actions such as mastication, communication and swallowing. It houses and provides protection for the tongue, teeth and salivary glands. The mandible is unique in that it has two anatomically identical articulations, each providing the same function. Both articulations, however, rarely have synchronous force and motion characteristics. The mandible is the only moveable bone in the skull and is capable of the following motions: depression - lowering the mandible, as in yawning, elevation - raising the mandible, protraction - thrusting the jaw forward, retraction - withdrawing the jaw posteriorly, and lateral deviation - sideways displacement in the transverse plane. The mandible is an irregular bone comprising a broad U shaped body with two ascending rami. The rami are quadrilateral plate like structures with lateral sides which are nearly flat. The mandible is subjected to repetitive loading and is susceptible to wear at its articulations, cyclic fatigue and dislocation. Despite the importance of the mandible little is understood about its mechanical properties and loading parameters. The purpose of this study was to create a three dimensional geometric model of a human mandible based on anatomical data. A 21 year old male with no history of mandible fracture or temporomandibular joint dysfunction was selected. The mandible was non-invasively imaged by Computed Tomography (CT). The subject was imaged lying on his back with the head supported and immobilised by a U shaped head rest. Seventeen parallel cross-sectional images oblique to the transverse plane were constructed. Cortical and cancellous bone boundaries were manually digitised for every image using a Science Accessories Corporation GP-9 digitiser linked to an IBM 286 SX personal computer. The data was transferred to a global coordinate system and entered into MSC/PATRAN finite element

Incorporating multislice imaging into x-ray CT polymer gel dosimetry

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Johnston, H., E-mail: holly.johnston@utsw.edu [Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia V8W 2Y2 (Canada); Hilts, M. [Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia V8W 2Y2, Canada and Medical Physics, BC Cancer Agency, Vancouver Island Centre, Victoria, British Columbia V8R 6V5 (Canada); Jirasek, A. [Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia V8W 2Y2, Canada and Department of Physics, University of British Columbia—Okanagan Campus, Kelowna, British Columbia V1V 1V7 (Canada)

2015-04-15

Purpose: To evaluate multislice computed tomography (CT) scanning for fast and reliable readout of radiation therapy (RT) dose distributions using CT polymer gel dosimetry (PGD) and to establish a baseline assessment of image noise and uniformity in an unirradiated gel dosimeter. Methods: A 16-slice CT scanner was used to acquire images through a 1 L cylinder filled with water. Additional images were collected using a single slice machine. The variability in CT number (N{sub CT}) associated with the anode heel effect was evaluated and used to define a new slice-by-slice background subtraction artifact removal technique for CT PGD. Image quality was assessed for the multislice system by evaluating image noise and uniformity. The agreement in N{sub CT} for slices acquired simultaneously using the multislice detector array was also examined. Further study was performed to assess the effects of increasing x-ray tube load on the constancy of measured N{sub CT} and overall scan time. In all cases, results were compared to the single slice machine. Finally, images were collected throughout the volume of an unirradiated gel dosimeter to quantify image noise and uniformity before radiation is delivered. Results: Slice-by-slice background subtraction effectively removes the variability in N{sub CT} observed across images acquired simultaneously using the multislice scanner and is the recommended background subtraction method when using a multislice CT system. Image noise was higher for the multislice system compared to the single slice scanner, but overall image quality was comparable between the two systems. Further study showed N{sub CT} was consistent across image slices acquired simultaneously using the multislice detector array for each detector configuration of the slice thicknesses examined. In addition, the multislice system was found to eliminate variations in N{sub CT} due to increasing x-ray tube load and reduce scanning time by a factor of 4 when compared to

MR imaging and CT findings after liver transplantation

International Nuclear Information System (INIS)

Langer, M.; Langer, R.; Scholz, A.; Zwicker, C.; Astinet, F.

1990-01-01

The aim of the paper is to evaluate MR imaging and dynamic CT as noninvasive procedures to image signs of graft failure after an orthotopic liver transplantation (OLT). Thirty MR studies and 50 dynamic CT examinations were performed within 20 days after OLT. MR examinations were performed with a 0.5-T Siemens Magnetom. CT scans were obtained by using a Siemens Somatom Plus. In all patients, MR images demonstrated a perivascular rim of intermediate signal intensity on T1-weighted and increased signal intensity on T2-weighted images in the hilum of the liver; in 20/26, this was seen in peripheral areas also. In all patients, a perivascular area of low attenuation was diagnosed at angio-CT

Comparison of CT myelography performed in the prone and supine positions in the detection of cervical spinal stenosis

International Nuclear Information System (INIS)

Blease Graham, Cole III; Wippold, Franz J. II; Bae, Kyongtae T.; Pilgram, Thomas K.; Shaibani, Ali; Kido, Daniel K.

2001-01-01

AIM: To quantify the change in the cross-sectional area of the cervical spinal cord and subarachnoid space (SAS) in the supine neutral vs prone extension positions in patients with myelopathy undergoing cervical CT myelography. MATERIAL AND METHODS: Axial CT myelgrams of 21 myelopathic patients were performed in both the supine neutral and prone extension positions. The SAS and cord cross-sectional areas were then measured at the disk spaces and mid-pedicle levels from C2 to T1 in both the supine and prone positions using a public domain NIH Image program, version 156b18. Mean area measurements in both positions were then compared for each level examined. RESULTS: Mean SAS cross-sectional area in the prone position was notably reduced compared with the supine position at C4-C5 [128.8 mm 2 vs 168.1 mm 2 (P 2 vs 143.2 mm 2 (P< .05)] disk levels. The mean cord cross-sectional area failed to change signficantly with positioning. CONCLUSIONS: Prone myelography may demonstrate a greater degree of cervical spine stenosis compared with CT myelography performed in the supine position in myelopathic patients. Imaging with the patient prone with neck extended in both myelography and CTM may improve precision in the results of measurements of the stenotic spinal canal when comparing these two methods. Blease Graham III, C. (2001)

CT and MR imaging findings of sinonasal angiomatous polyps

Energy Technology Data Exchange (ETDEWEB)

Zou, Jing [Department of Radiology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong (China); Man, Fengyuan [Department of Radiology, Beijing Tongren Hospital, Capital Medical University, Beijing (China); Deng, Kai [Department of Radiology, Qingdao No. 4 People' s Hospital, Qingdao, Shandong (China); Zheng, Yuanyuan [Department of Radiology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong (China); Hao, Dapeng, E-mail: haodp_2009@163.com [Department of Radiology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong (China); Xu, Wenjian, E-mail: cjr.xuwenjian@vip.163.com [Department of Radiology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong (China)

2014-03-15

Objective: To characterize the CT and MR imaging findings of patients with sinonasal angiomatous polyps (SAPs) and evaluate their respective clinical value in the diagnosis of SAP. Methods: CT and MR imaging findings of 15 patients with pathologically proven SAP were examined. Assessed image features included location, size, margin, attenuation, and change of the bony walls of the sinonasal cavity on CT, and signal intensity and enhancement pattern on MR. Results: On CT, the SAP was mostly isoattenuated with patches of slight hyperattenuation. Most lesions caused changes in the adjacent bone, including expansile remodeling (n = 8), defect or destruction (n = 7), and hyperostosis (n = 6). All lesions examined by MR showed heterogeneous isointense signal intensity on T1-weighted images and mixed obvious hyperintense and hypointense signal intensity with linear hypointense septum internally (n = 10), and hypointense peripheral rim on T2-weighted images (n = 10). Postcontrast MR images demonstrated areas of heterogeneous and marked enhancement with an unenhanced hypointense rim and septa (n = 7). Conclusions: CT and MR imaging have respective advantages in the diagnosis of SAP. Combined application of CT and MR examinations is necessary for patients with suspected SAP.

CT and MR imaging findings of sinonasal angiomatous polyps

International Nuclear Information System (INIS)

Zou, Jing; Man, Fengyuan; Deng, Kai; Zheng, Yuanyuan; Hao, Dapeng; Xu, Wenjian

2014-01-01

Objective: To characterize the CT and MR imaging findings of patients with sinonasal angiomatous polyps (SAPs) and evaluate their respective clinical value in the diagnosis of SAP. Methods: CT and MR imaging findings of 15 patients with pathologically proven SAP were examined. Assessed image features included location, size, margin, attenuation, and change of the bony walls of the sinonasal cavity on CT, and signal intensity and enhancement pattern on MR. Results: On CT, the SAP was mostly isoattenuated with patches of slight hyperattenuation. Most lesions caused changes in the adjacent bone, including expansile remodeling (n = 8), defect or destruction (n = 7), and hyperostosis (n = 6). All lesions examined by MR showed heterogeneous isointense signal intensity on T1-weighted images and mixed obvious hyperintense and hypointense signal intensity with linear hypointense septum internally (n = 10), and hypointense peripheral rim on T2-weighted images (n = 10). Postcontrast MR images demonstrated areas of heterogeneous and marked enhancement with an unenhanced hypointense rim and septa (n = 7). Conclusions: CT and MR imaging have respective advantages in the diagnosis of SAP. Combined application of CT and MR examinations is necessary for patients with suspected SAP

The Appendix on CT

Energy Technology Data Exchange (ETDEWEB)

Whitley, S. [Sunnybrook Health Sciences Center, Toronto, Ontario (Canada); Barts and the Royal London, Royal London Hospital, Whitechapel, London (United Kingdom)], E-mail: siobhanwhitley@yahoo.co.uk; Sookur, P.; McLean, A.; Power, N. [Barts and the Royal London, Royal London Hospital, Whitechapel, London (United Kingdom)

2009-02-15

Appendicitis can be a difficult clinical diagnosis to make. A negative appendicectomy rate of 20% has traditionally been accepted as the consequences of appendiceal perforation can be grave. Cross-sectional imaging is increasingly being employed in the investigation of adults with suspected appendicitis. This review will demonstrate the appearance of the normal appendix on computed tomography (CT) and its appearance in a range of inflammatory and neoplastic processes including appendicitis, Crohn's disease, infections, and benign and malignant tumour000.

Associations of Age, BMI, and Years of Menstruation with Proximal Femur Strength in Chinese Postmenopausal Women: A Cross-Sectional Study

Directory of Open Access Journals (Sweden)

Huili Kang

2016-01-01

Full Text Available This study aimed to elucidate the associations of age, BMI, and years of menstruation with proximal femur strength in Chinese postmenopausal women, which may improve the prediction of hip fracture risk. A cross-sectional study was conducted in 1322 Chinese postmenopausal women recruited from communities. DXA images were used to generate bone mineral density (BMD and geometric parameters, including cross-sectional area (CSA, outer diameter (OD, cortical thickness (CT, section modulus (SM, buckling ratio (BR at the narrow neck (NN, intertrochanter (IT, and femoral shaft (FS. Relationships of age, BMI, and years of menstruation with bone phenotypes were analyzed with the adjustment of height, age at menarche, total daily physical activity, education, smoking status, calcium tablet intake, etc. Age was associated with lower BMD, CSA, CT, SM, and higher BR (p < 0.05, which indicated a weaker bone strength at the proximal femur. BMI and years of menstruation had the positive relationships with proximal femur strength (p < 0.05. Further analyses showed that the ranges of absolute value of change slope per year, per BMI or per year of menstruation were 0.14%–1.34%, 0.20%–2.70%, and 0.16%–0.98%, respectively. These results supported that bone strength deteriorated with aging and enhanced with higher BMI and longer time of years of menstruation in Chinese postmenopausal women.

Photoionization cross section by Stieltjes imaging applied to coupled cluster Lanczos pseudo-spectra

Energy Technology Data Exchange (ETDEWEB)

Cukras, Janusz; Coriani, Sonia; Decleva, Piero [Dipartimento di Scienze Chimiche e Farmaceutiche, Università degli Studi di Trieste, via L. Giorgieri 1, I-34127 Trieste (Italy); Christiansen, Ove [Department of Chemistry, Aarhus University, DK-8000 Aarhus C (Denmark); Norman, Patrick [Department of Physics, Chemistry and Biology, Linköping University, SE-581 83 Linköping (Sweden)

2013-09-07

A recently implemented asymmetric Lanczos algorithm for computing (complex) linear response functions within the coupled cluster singles (CCS), coupled cluster singles and iterative approximate doubles (CC2), and coupled cluster singles and doubles (CCSD) is coupled to a Stieltjes imaging technique in order to describe the photoionization cross section of atoms and molecules, in the spirit of a similar procedure recently proposed by Averbukh and co-workers within the Algebraic Diagrammatic Construction approach. Pilot results are reported for the atoms He, Ne, and Ar and for the molecules H{sub 2}, H{sub 2}O, NH{sub 3}, HF, CO, and CO{sub 2}.

Reconstructed coronal views of CT and isotopic images of the pancreas

International Nuclear Information System (INIS)

Kasuga, Toshio; Kobayashi, Toshio; Nakanishi, Fumiko

1980-01-01

To compare functional images of the pancreas by scintigraphy with morphological views of the pancreas by CT, CT coronal views of the pancreas were reconstructed. As CT coronal views were reconstructed from the routine scanning, there was a problem in longitudinal spatial resolution. However, almost satisfactory total images of the pancreas were obtained by improving images adequately. In 27 patients whose diseases had been confirmed, it was easy to compare pancreatic scintigrams with pancreatic CT images by using reconstructed CT coronal views, and information which had not been obtained by original CT images could be obtained by using reconstructed CT coronal views. Especially, defects on pancreatic images and the shape of pancreas which had not been visualized clearly by scintigraphy alone could be visualized by using reconstructed CT coronal views of the pancreas. (Tsunoda, M.)

Blind CT image quality assessment via deep learning strategy: initial study

Science.gov (United States)

Li, Sui; He, Ji; Wang, Yongbo; Liao, Yuting; Zeng, Dong; Bian, Zhaoying; Ma, Jianhua

2018-03-01

Computed Tomography (CT) is one of the most important medical imaging modality. CT images can be used to assist in the detection and diagnosis of lesions and to facilitate follow-up treatment. However, CT images are vulnerable to noise. Actually, there are two major source intrinsically causing the CT data noise, i.e., the X-ray photo statistics and the electronic noise background. Therefore, it is necessary to doing image quality assessment (IQA) in CT imaging before diagnosis and treatment. Most of existing CT images IQA methods are based on human observer study. However, these methods are impractical in clinical for their complex and time-consuming. In this paper, we presented a blind CT image quality assessment via deep learning strategy. A database of 1500 CT images is constructed, containing 300 high-quality images and 1200 corresponding noisy images. Specifically, the high-quality images were used to simulate the corresponding noisy images at four different doses. Then, the images are scored by the experienced radiologists by the following attributes: image noise, artifacts, edge and structure, overall image quality, and tumor size and boundary estimation with five-point scale. We trained a network for learning the non-liner map from CT images to subjective evaluation scores. Then, we load the pre-trained model to yield predicted score from the test image. To demonstrate the performance of the deep learning network in IQA, correlation coefficients: Pearson Linear Correlation Coefficient (PLCC) and Spearman Rank Order Correlation Coefficient (SROCC) are utilized. And the experimental result demonstrate that the presented deep learning based IQA strategy can be used in the CT image quality assessment.

The role of hybrid SPECT-CT in oncology: current and emerging clinical applications

International Nuclear Information System (INIS)

Chowdhury, F.U.; Scarsbrook, A.F.

2008-01-01

Single photon emission computed tomography - computed tomography (SPECT-CT) is an emerging dual-modality imaging technique with many established and potential clinical applications in the field of oncology. To date, there has been a considerable emphasis on the benefits of integrated positron emission tomography - computed tomography (PET-CT) in oncology, but relatively little focus on the clinical utility of SPECT-CT. As with PET-CT, accurate co-registration of anatomical and functional data from a combined SPECT-CT camera often provides complementary diagnostic information. Both sensitivity (superior disease localization) and specificity (exclusion of false-positives due to physiological tracer uptake) are improved, and the functional significance of indeterminate lesions detected on cross-sectional imaging can be defined. This article will review the scope of hybrid SPECT-CT in oncology and illustrate both current and emerging clinical applications

CT and MR imaging characteristics of infantile hepatic hemangioendothelioma

International Nuclear Information System (INIS)

Feng Shiting; Chan Tao; Ching, A.S.C.; Sun Canhui; Guo Huanyi; Fan Miao; Meng Quanfei; Li Ziping

2010-01-01

Aim: This study aims to analyze computed tomography (CT) and magnetic resonance (MR) imaging features of infantile hepatic hemangioendotheliomas before and after treatment. Materials and methods: CT and MR examinations of seven infants with biopsy proven hepatic hemangioendotheliomas were retrospectively analyzed. The distribution, number, size, imaging appearance, enhancement pattern and post-treatment changes of the tumors were evaluated. Results: A total of 153 hepatic hemangioendotheliomas were detected on CT (111) and MR (42) imaging. In six infants, 109/111 (98.2%) tumors were hypodense and 2/111 (1.8%) lesions contained calcification on unenhanced CT. On MR imaging, all 42 lesions in one infant were heterogeneously T1-hypointense and T2-hyperintense compared to the normal liver parenchyma. Contrast-enhanced CT and MRI showed peripheral rim (51.6%), uniform (48.4%), fibrillary (33.3%), and nodular (28.8%) contrast enhancement in the hepatic arterial phase. Homogeneous (100%), rim (98.2%) and mixed enhancement patterns were noted in tumors 2.0 cm and 1.0-2.0 cm in diameter respectively in the hepatic arterial phase. In three patients who underwent steroid therapy, follow-up CT examination demonstrated tumor size reduction and increased intra-tumoral calcification in two patients. Conclusion: Infantile hepatic hemangioendotheliomas show some typical imaging features and size-dependent pattern of contrast enhancement on CT and MR imaging, which allow accurate imaging diagnosis and post-treatment evaluation.

Paleoradiology: advanced CT in the evaluation of nine Egyptian mummies.

Science.gov (United States)

Hoffman, Heidi; Torres, William E; Ernst, Randy D

2002-01-01

Axial thin-collimation state-of-the-art spiral computed tomography (CT) was combined with sagittal and coronal reformatting, three-dimensional (3D) reconstruction, and virtual "fly-through" techniques to nondestructively study nine Egyptian mummies. These techniques provided important paleopathologic and historical information about mummification techniques, depicted anatomy in the most informative imaging plane, illustrated the soft-tissue preservation and physical appearance of mummies in superb detail, and generated an intriguing virtual tour through hollow mummified remains without harming the specimens themselves. Images generated with these methods can help archaeologists and Egyptologists understand these fascinating members of mankind and can serve as adjunct visual aids for laypersons who are interested in mummies. CT has emerged as the imaging modality of choice for the examination of Egyptian mummies due to its noninvasive cross-sectional nature and inherently superior contrast and spatial resolution. As multi-detector row CT and postprocessing tools evolve, the capabilities and applications of CT will continue to proliferate, attesting to the expanded versatility and utility of CT as a noninvasive research tool in the multidisciplinary study of Egyptian mummies. Copyright RSNA, 2002

CT image registration in sinogram space.

Science.gov (United States)

Mao, Weihua; Li, Tianfang; Wink, Nicole; Xing, Lei

2007-09-01

Object displacement in a CT scan is generally reflected in CT projection data or sinogram. In this work, the direct relationship between object motion and the change of CT projection data (sinogram) is investigated and this knowledge is applied to create a novel algorithm for sinogram registration. Calculated and experimental results demonstrate that the registration technique works well for registering rigid 2D or 3D motion in parallel and fan beam samplings. Problem and solution for 3D sinogram-based registration of metallic fiducials are also addressed. Since the motion is registered before image reconstruction, the presented algorithm is particularly useful when registering images with metal or truncation artifacts. In addition, this algorithm is valuable for dealing with situations where only limited projection data are available, making it appealing for various applications in image guided radiation therapy.

CT image registration in sinogram space

International Nuclear Information System (INIS)

Mao Weihua; Li Tianfang; Wink, Nicole; Xing Lei

2007-01-01

Object displacement in a CT scan is generally reflected in CT projection data or sinogram. In this work, the direct relationship between object motion and the change of CT projection data (sinogram) is investigated and this knowledge is applied to create a novel algorithm for sinogram registration. Calculated and experimental results demonstrate that the registration technique works well for registering rigid 2D or 3D motion in parallel and fan beam samplings. Problem and solution for 3D sinogram-based registration of metallic fiducials are also addressed. Since the motion is registered before image reconstruction, the presented algorithm is particularly useful when registering images with metal or truncation artifacts. In addition, this algorithm is valuable for dealing with situations where only limited projection data are available, making it appealing for various applications in image guided radiation therapy

In-room CT techniques for image-guided radiation therapy

International Nuclear Information System (INIS)

Ma, C.-M. Charlie; Paskalev, Kamen M.S.

2006-01-01

Accurate patient setup and target localization are essential to advanced radiation therapy treatment. Significant improvement has been made recently with the development of image-guided radiation therapy, in which image guidance facilitates short treatment course and high dose per fraction radiotherapy, aiming at improving tumor control and quality of life. Many imaging modalities are being investigated, including x-ray computed tomography (CT), ultrasound imaging, positron emission tomography, magnetic resonant imaging, magnetic resonant spectroscopic imaging, and kV/MV imaging with flat panel detectors. These developments provide unique imaging techniques and methods for patient setup and target localization. Some of them are different; some are complementary. This paper reviews the currently available kV x-ray CT systems used in the radiation treatment room, with a focus on the CT-on-rails systems, which are diagnostic CT scanners moving on rails installed in the treatment room. We will describe the system hardware including configurations, specifications, operation principles, and functionality. We will review software development for image fusion, structure recognition, deformation correction, target localization, and alignment. Issues related to the clinical implementation of in-room CT techniques in routine procedures are discussed, including acceptance testing and quality assurance. Clinical applications of the in-room CT systems for patient setup, target localization, and adaptive therapy are also reviewed for advanced radiotherapy treatments

Importance of PET/CT for imaging of colorectal cancer

International Nuclear Information System (INIS)

Meinel, F.G.; Schramm, N.; Graser, A.; Reiser, M.F.; Rist, C.; Haug, A.R.

2012-01-01

Fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) has emerged as a very useful imaging modality in the management of colorectal carcinoma. Data from the literature regarding the role of PET/CT in the initial diagnosis, staging, radiotherapy planning, response monitoring and surveillance of colorectal carcinoma is presented. Future directions and economic aspects are discussed. Computed tomography (CT), magnetic resonance imaging (MRI) and FDG-PET for colorectal cancer and endorectal ultrasound for rectal cancer. Combined FDG-PET/CT. While other imaging modalities allow superior visualization of the extent and invasion depth of the primary tumor, PET/CT is most sensitive for the detection of distant metastases of colorectal cancer. We recommend a targeted use of PET/CT in cases of unclear M staging, prior to metastasectomy and in suspected cases of residual or recurrent colorectal carcinoma with equivocal conventional imaging. The role of PET/CT in radiotherapy planning and response monitoring needs to be determined. Currently there is no evidence to support the routine use of PET/CT for colorectal screening, staging or surveillance. To optimally exploit the synergy between morphologic and functional information, FDG-PET should generally be performed as an integrated FDG-PET/CT with a contrast-enhanced CT component in colorectal carcinoma. (orig.) [de

Bubble-like appearances are characteristic thin-section CT findings of adenocarcinoma

International Nuclear Information System (INIS)

Kojima, Yoko; Saito, Haruhiro; Ito, Hiroyuki

2008-01-01

Adenocarcinomas are often diagnosed as old inflammatory lesions which are sometimes overlooked. Some of these adenocarcinomas display characteristic thin-section computed tomography (TS-CT) findings. We reported on these bubble-like appearances (BLA). We studied the BLA characteristics of adenocarcinomas. We reviewed the TS-CT findings of 17 (6 men, 11 women) cases of adenocarcinoma with bubble-like appearances. All 17 patients had undergone surgery between August 2003 and March 2007. We studied correlations between the TS-CT findings, the pathological findings and the clinical characteristics. The average tumor diameter was 35.4 mm. The definition of BLA is; having a irregular shape with straight margins, peripheral ground-glass opacity (GGO), dilated air bronchograms (more than 3), prominent pleural indentation. The pathological characteristics of tumors with BLA were; peripheral bronchioloalveolar cell carcinoma (BAC) patterns, almost total collapse (about 80% of the tumor area), and several ectatic small bronchi. Six cases were initially overlooked, because the TS-CT findings appeared as old inflammation. The average tumor doubling time was 1167 days. After resection, there have been no recurrences. On TS-CT images, BLA type adenocarcinomas appear as irregular in shape and they have a very slow doubling time. These types of lesions require careful attention because they are often diagnosed as old inflammatory scarring. (author)

High energy X-ray CT system using a linear accelerator for automobile parts inspection

International Nuclear Information System (INIS)

Kanamori, T.; Sukita, T.

1995-01-01

A high energy X-ray CT system (maximum photon energy: 0.95 MeV) has been developed for industrial use. This system employs a linear accelerator as an X-ray source. It is able to image the cross section of automobile parts and can be applied to a solidification analysis study of the cylinder head in an automobile. This paper describes the features of the system and application results which can be related to solidification analysis of the cylinder head when fabricated from an aluminum casting. Some cross-sectional images are also presented as evidence for nondestructive inspection of automobile parts. (orig.)

CT and MR imaging of the kidney and adrenal glands: CT of the kidney

International Nuclear Information System (INIS)

Levine, E.

1987-01-01

Because of its high diagnostic yield, safety, and cost-effectiveness, CT has become a major imaging technique for evaluating the kidney. CT is highly accurate for determining the nature and extent of renal masses, and this has become the main indication for renal CT. However, CT is also valuable in assessing patients with renal cystic disease, trauma, inflammatory disease, infarction, hemorrhage and hydronephrosis of unknown cause. This presentation reviews the normal CT anatomy of the kidneys and the usefulness of CT in the diagnosis of all these conditions. Examination techniques are discussed with particular emphasis on avoiding diagnostic pitfalls and tailoring the examination to the nature of the clinical problem. CT findings in various renal disorders are compared with those of other imaging techniques, particularly US and angiography, and the place of CT in the diagnostic approach to these disorders is considered

CT Image Reconstruction in a Low Dimensional Manifold

OpenAIRE

Cong, Wenxiang; Wang, Ge; Yang, Qingsong; Hsieh, Jiang; Li, Jia; Lai, Rongjie

2017-01-01

Regularization methods are commonly used in X-ray CT image reconstruction. Different regularization methods reflect the characterization of different prior knowledge of images. In a recent work, a new regularization method called a low-dimensional manifold model (LDMM) is investigated to characterize the low-dimensional patch manifold structure of natural images, where the manifold dimensionality characterizes structural information of an image. In this paper, we propose a CT image reconstruc...

Cardiac MR imaging: Comparison with echocardiography and dynamic CT

International Nuclear Information System (INIS)

Colletti, P.M.; Norris, S.; Raval, J.; Boswell, W.; Lee, K.; Ralls, P.; Haywood, J.; Halls, J.

1986-01-01

The authors compared gated cardiac MR imaging with two-dimensional and Doppler echocardiography and dynamic CT. Gated cardiac MR imaging (VISTA unit, 0.5 T) was performed in 55 patients with a variety of conditions. Accuracy of diagnosis was compared. CT showed arterial, valvular, and pericardial calcifications not seen on MR imaging. Many lesions were seen as well on CT as on MR imaging. Two-dimensional echocardiography was superior in demonstrating wall motion and valvular disease. MR imaging was superior in demonstrating myocardial structures

Bronchial morphometry in smokers: comparison with healthy subjects by using 3D CT

International Nuclear Information System (INIS)

Montaudon, Michel; Berger, Patrick; Marthan, Roger; Lederlin, Mathieu; Tunon-de-Lara, Jose Manuel; Laurent, Francois

2009-01-01

The assessment of airway dimensions in patients with airway disease by using computed tomography (CT) has been limited by the obliquity of bronchi, the ability to identify the bronchial generation, and the limited number of bronchial measurements. The aims of the present study were (i) to analyze cross-sectional bronchial dimensions after automatic orthogonal reconstruction of all visible bronchi on CT images, and (ii) to compare bronchial morphometry between smokers and nonsmokers. CT and pulmonary function tests were performed in 18 males separated into two groups: 9 nonsmokers and 9 smokers. Bronchial wall area (WA) and lumen area (LA) were assessed using dedicated 3D software able to provide accurate cross-sectional measurements of all visible bronchi on CT. WA/LA and WA/(WA+LA) ratios were computed and all parameters were compared between both groups. Smokers demonstrated greater WA, smaller LA, and consequently greater LA/WA and LA/(WA+LA) ratios than nonsmokers. These differences occurred downward starting at the fourth bronchial generation. 3D quantitative CT method is able to demonstrate significant changes in bronchial morphometry related to tobacco consumption. (orig.)

Automated curved planar reformation of 3D spine images

International Nuclear Information System (INIS)

Vrtovec, Tomaz; Likar, Bostjan; Pernus, Franjo

2005-01-01

Traditional techniques for visualizing anatomical structures are based on planar cross-sections from volume images, such as images obtained by computed tomography (CT) or magnetic resonance imaging (MRI). However, planar cross-sections taken in the coordinate system of the 3D image often do not provide sufficient or qualitative enough diagnostic information, because planar cross-sections cannot follow curved anatomical structures (e.g. arteries, colon, spine, etc). Therefore, not all of the important details can be shown simultaneously in any planar cross-section. To overcome this problem, reformatted images in the coordinate system of the inspected structure must be created. This operation is usually referred to as curved planar reformation (CPR). In this paper we propose an automated method for CPR of 3D spine images, which is based on the image transformation from the standard image-based to a novel spine-based coordinate system. The axes of the proposed spine-based coordinate system are determined on the curve that represents the vertebral column, and the rotation of the vertebrae around the spine curve, both of which are described by polynomial models. The optimal polynomial parameters are obtained in an image analysis based optimization framework. The proposed method was qualitatively and quantitatively evaluated on five CT spine images. The method performed well on both normal and pathological cases and was consistent with manually obtained ground truth data. The proposed spine-based CPR benefits from reduced structural complexity in favour of improved feature perception of the spine. The reformatted images are diagnostically valuable and enable easier navigation, manipulation and orientation in 3D space. Moreover, reformatted images may prove useful for segmentation and other image analysis tasks

Plant Identification Based on Leaf Midrib Cross-Section Images Using Fractal Descriptors.

Directory of Open Access Journals (Sweden)

Núbia Rosa da Silva

Full Text Available The correct identification of plants is a common necessity not only to researchers but also to the lay public. Recently, computational methods have been employed to facilitate this task, however, there are few studies front of the wide diversity of plants occurring in the world. This study proposes to analyse images obtained from cross-sections of leaf midrib using fractal descriptors. These descriptors are obtained from the fractal dimension of the object computed at a range of scales. In this way, they provide rich information regarding the spatial distribution of the analysed structure and, as a consequence, they measure the multiscale morphology of the object of interest. In Biology, such morphology is of great importance because it is related to evolutionary aspects and is successfully employed to characterize and discriminate among different biological structures. Here, the fractal descriptors are used to identify the species of plants based on the image of their leaves. A large number of samples are examined, being 606 leaf samples of 50 species from Brazilian flora. The results are compared to other imaging methods in the literature and demonstrate that fractal descriptors are precise and reliable in the taxonomic process of plant species identification.

Diagnostic CT imaging of the heart and aorta in health and disease

International Nuclear Information System (INIS)

Watanabe, Shigeru

1981-01-01

Despite recent remarkable developments in computed tomography (CT) for many organs in the human body, its clinical application concerning the cardiovascular system has been slow. In this study, we investigated clinical applications of CT for the cardiovascular system. We used conventional CT without ECG synchronization and ECG-synchronized CT. By the former, the size, the shape, and the arrangement of cardiovascular structures and the presence of pericardial effusion and calcifications were shown. For the latter, ECG gating method and data sorting method were used, and the cardiac border movement, the sequential changes of cross-sectional cardiac areas and the changing ratio were studied by both methods. The cardiac CT was found to be a useful noninvasive method for observation of anatomical features in various cardiovascular diseases and for the analysis of cardiac motion - especially, dyssynergia such as hypokinesis, akinesis and paradoxical movement in myocardial infarctions. (author)

Thin section helical CT findings of klastskin tumor and benign stricture: cholangiographic correlation

International Nuclear Information System (INIS)

Choi, Guk Myeong; Han, Joon Koo; Kim, Tae Kyoung; Choi, Byung Ihn; Kim, Sun Whe; Cho, Yun Ku; Han, Man Chung; Yeon, Kyung Mo

1997-01-01

The purpose of this study was 1) to describe the thin section helical CT findings of hilar cholangiocarcinoma and of benign strcture, and to discuss the differential points between the two disease entities and 2) using cholangiographic correlation, to evaluate the diagnostic accuracy of helical CT in determining the extent of hilar cholangiocarcinoma. Twenty-seven patients with hilar cholangiocarcinoma and eight with benign biliary dilatation were studied. All except four with hilar cholangiocarcinoma, who underwentCT using a conventional scanner, were studied with two-phase helical CT. In all patients, cholangiographs were obtained by digital fluoroscopy after the injection of contrast materials into PTBD catheters. The level of obstruction was classified according to Bismuth, and 35 CT scans were studied blindly and retrospectively by two radiologists. The findings were analyzed for the presence of tumor, and then divided into two groups(cholangiocarcinomas and benign strictures), and the positive predictive value was calculated. The CT images of klatskin tumor were analyzed with special emphasis on the level and shape of the hilar obstruction. The level of biliary obstruction and extent of the tumor were carefully correlated with the results of cholangiography. Thin-section spiral CT correctly identified all tumor mass as a focal wall thickening obliterating the lumen. On arterial/portal phase CT scanning, 81% of infilterative tumors showed high attenuation. In all patients, differentiation between benign stricture and klaskin tumor was possible;correct identification of the level of obstruction and extent of tumor, according to Bismuth's classification, was possible in 63% of cases. For correct diagnosis of hilar cholangiocarcinoma and differentiation of benign stricture, helical CT was highly accurate and effective. Because of limital Z-axis resolution, however, the exact intraductal extent of the tumor was less accorately diagnosed.=20

Patient-specific estimation of detailed cochlear shape from clinical CT images

DEFF Research Database (Denmark)

Kjer, H Martin; Fagertun, Jens; Wimmer, Wilhelm

2018-01-01

of the detailed patient-specific cochlear shape from CT images. From a collection of temporal bone [Formula: see text]CT images, we build a cochlear statistical deformation model (SDM), which is a description of how a human cochlea deforms to represent the observed anatomical variability. The model is used...... for regularization of a non-rigid image registration procedure between a patient CT scan and a [Formula: see text]CT image, allowing us to estimate the detailed patient-specific cochlear shape. We test the accuracy and precision of the predicted cochlear shape using both [Formula: see text]CT and CT images...

Experimental validation of heterogeneity-corrected dose-volume prescription on respiratory-averaged CT images in stereotactic body radiotherapy for moving tumors

International Nuclear Information System (INIS)

Nakamura, Mitsuhiro; Miyabe, Yuki; Matsuo, Yukinori; Kamomae, Takeshi; Nakata, Manabu; Yano, Shinsuke; Sawada, Akira; Mizowaki, Takashi; Hiraoka, Masahiro

2012-01-01

The purpose of this study was to experimentally assess the validity of heterogeneity-corrected dose-volume prescription on respiratory-averaged computed tomography (RACT) images in stereotactic body radiotherapy (SBRT) for moving tumors. Four-dimensional computed tomography (CT) data were acquired while a dynamic anthropomorphic thorax phantom with a solitary target moved. Motion pattern was based on cos (t) with a constant respiration period of 4.0 sec along the longitudinal axis of the CT couch. The extent of motion (A 1 ) was set in the range of 0.0–12.0 mm at 3.0-mm intervals. Treatment planning with the heterogeneity-corrected dose-volume prescription was designed on RACT images. A new commercially available Monte Carlo algorithm of well-commissioned 6-MV photon beam was used for dose calculation. Dosimetric effects of intrafractional tumor motion were then investigated experimentally under the same conditions as 4D CT simulation using the dynamic anthropomorphic thorax phantom, films, and an ionization chamber. The passing rate of γ index was 98.18%, with the criteria of 3 mm/3%. The dose error between the planned and the measured isocenter dose in moving condition was within ± 0.7%. From the dose area histograms on the film, the mean ± standard deviation of the dose covering 100% of the cross section of the target was 102.32 ± 1.20% (range, 100.59–103.49%). By contrast, the irradiated areas receiving more than 95% dose for A 1 = 12 mm were 1.46 and 1.33 times larger than those for A 1 = 0 mm in the coronal and sagittal planes, respectively. This phantom study demonstrated that the cross section of the target received 100% dose under moving conditions in both the coronal and sagittal planes, suggesting that the heterogeneity-corrected dose-volume prescription on RACT images is acceptable in SBRT for moving tumors.

Imaging lobular breast carcinoma: comparison of synchrotron radiation DEI-CT technique with clinical CT, mammography and histology

Science.gov (United States)

Fiedler, S.; Bravin, A.; Keyriläinen, J.; Fernández, M.; Suortti, P.; Thomlinson, W.; Tenhunen, M.; Virkkunen, P.; Karjalainen-Lindsberg, M.-L.

2004-01-01

Different modalities for imaging cancer-bearing breast tissue samples are described and compared. The images include clinical mammograms and computed tomography (CT) images, CT images with partly coherent synchrotron radiation (SR), and CT and radiography images taken with SR using the diffraction enhanced imaging (DEI) method. The images are evaluated by a radiologist and compared with histopathological examination of the samples. Two cases of lobular carcinoma are studied in detail. The indications of cancer are very weak or invisible in the conventional images, but the morphological changes due to invasion of cancer become pronounced in the images taken by the DEI method. The strands penetrating adipose tissue are seen clearly in the DEI-CT images, and the histopathology confirms that some strands contain the so-called 'Indian file' formations of cancer cells. The radiation dose is carefully measured for each of the imaging modalities. The mean glandular dose (MGD) for 50% glandular breast tissue is about 1 mGy in conventional mammography and less than 0.25 mGy in projection DEI, while in the clinical CT imaging the MGD is very high, about 45 mGy. The entrance dose of 95 mGy in DEI-CT imaging gives rise to an MGD of 40 mGy, but the dose may be reduced by an order of magnitude, because the contrast is very large in most images.

Advances in CT imaging for urolithiasis

Directory of Open Access Journals (Sweden)

Yasir Andrabi

2015-01-01

Full Text Available Urolithiasis is a common disease with increasing prevalence worldwide and a lifetime-estimated recurrence risk of over 50%. Imaging plays a critical role in the initial diagnosis, follow-up and urological management of urinary tract stone disease. Unenhanced helical computed tomography (CT is highly sensitive (>95% and specific (>96% in the diagnosis of urolithiasis and is the imaging investigation of choice for the initial assessment of patients with suspected urolithiasis. The emergence of multi-detector CT (MDCT and technological innovations in CT such as dual-energy CT (DECT has widened the scope of MDCT in the stone disease management from initial diagnosis to encompass treatment planning and monitoring of treatment success. DECT has been shown to enhance pre-treatment characterization of stone composition in comparison with conventional MDCT and is being increasingly used. Although CT-related radiation dose exposure remains a valid concern, the use of low-dose MDCT protocols and integration of newer iterative reconstruction algorithms into routine CT practice has resulted in a substantial decrease in ionizing radiation exposure. In this review article, our intent is to discuss the role of MDCT in the diagnosis and post-treatment evaluation of urolithiasis and review the impact of emerging CT technologies such as dual energy in clinical practice.

Improved CT imaging in diagnosis of ankylosing spondylitis

International Nuclear Information System (INIS)

Mai Yuanfeng; Sun Haixing; Ling Jian; Kuang Jianyi; Pan Ximin

2006-01-01

Objective: To evaluate the improved CT imaging of sacroiliac joint in diagnosis of ankylosing spondylitis (AS). Methods: 22 patients, diagnosed as AS by clinical and radiography, undertook both conventional and improved CT imaging. All images were comparatively studied. Results: With conventional CT imaging, in the 44 joints of 22 cases, unremarkable images were obtained in 3 cases; early stage AS was found in 15 joints of 9 cases; AS in progressive stage was revealed in 8 cases/16 joints, stabled AS was presented in 2 cases/4 joints. There were 23 joints in 12 cases diagnosed as early term by improved imaging, progressive staged AS was shown in 8 cases/16 joints as, stable AS was demonstrated in 2 cases/4 joints. Conclusion: The improved imaging is sensitive in the diagnosis of early staged AS, for the application of thin slice scan, which helps to reduce partial volume effect. Scanning along the longitudinal axis of the sacroiliac joint extends the observation of erosion of the joint surface. For progressive or stable staged AS, the alterations of bone and joint space are prominent, improved CT imaging is not superior to the conventional. (authors)

Reconstruction CT imaging of the hypopharynx and the larynx

International Nuclear Information System (INIS)

Okuno, Tetsuji; Fujimura, Akiko; Murakami, Yasushi; Shiga, Hayao

1986-01-01

The multiplanar reconstruction CT imaging of the hypopharynx and the larynx was performed on a total of 20 cases: 8 with laryngeal carcinomas, 6 with hypopharyngeal carcinomas, 4 with vocal cord paralyses due to various causes, 1 with laryngeal amyloidosis, 1 with inflammatory granuloma of the hypopharynx. Coronal, segittal, and parasagittal reconstruction images were obtained from either 1 or 2 mm overlapping axial scans with 4 or 5 mm slice thickness (3 cases) using 5 sec scan times during queit breathing. In 15 cases with coronal reconstruction imaging, the anatomical derangements of the laryngopharyngeal structures especially along the undersurface of the true vocal cord to the false cord level, the lateral wall of the pyriform sinus, and the paraglottic space were demonstrated more clearly than the axial CT imaging. In 5 cases with sagittal reconstruction imaging, the vertical extension of the lesions through the anterior commisure was more clearly depicted than the axial CT imaging. In 8 cases with parasagittal reconstruction imaging, which is along the vocal fold or across the aryepiglottic fold, pathological changes along the aryepiglottic fold, the arytenoid-corniculate cartilage complex, and the tip of the pyriform sinus were more clearly demonstrated than the axial CT imaging. In determining the feasibility of conservation surgery of the larynx and the hypopharynx, reconstruction CT imaging is recommended as the diagnostic procedure of a choice, which would supplement the findings of the routine axial CT imaging. (author)

Evaluation of unusual causes of pancreatitis: Role of cross-sectional imaging

International Nuclear Information System (INIS)

Kwak, Sang Wook; Kim, Suk; Lee, Jun Woo; Lee, Nam Kyung; Kim, Chang Won; Yi, Mi Seon; Kim, Gwang Ha; Kang, Dae Hwan

2009-01-01

There are widely diverse causes of pancreatitis. Gallstone and alcohol have been recognized as the most common causes of pancreatitis accounting for 90% of cases. However, acute and chronic pancreatitis may also result from a variety of uncommon causes. The determination of the etiology is important for patient management and prevention of recurrence. Sludge is the most common cause of idiopathic or recurrent acute pancreatitis. Endoscopic ultrasonography is considered as the most accurate diagnostic test for this abnormality. Computed tomography (CT) and magnetic resonance imaging (MRI) have only a limited role in the diagnosis of sludge. However, papillitis observed on the contrast-enhanced CT and MR may provide clues to the detection of pancreatitis secondary to sludge, a small stone or a recently passed stone. Radiological studies, clinical presentation and laboratory data can be helpful in determining the etiology of unusual causes of pancreatitis such as anatomic anomalies, autoimmune pancreatitis, groove pancreatitis, and traumatic pancreatitis.

Evaluation of unusual causes of pancreatitis: Role of cross-sectional imaging

Energy Technology Data Exchange (ETDEWEB)

Kwak, Sang Wook [Department of Diagnostic Radiology, Pusan National University Hospital, Pusan National College of Medicine and the Medical Research Institute, Pusan National University, Busan 602-739 (Korea, Republic of); Kim, Suk [Department of Diagnostic Radiology, Pusan National University Hospital, Pusan National College of Medicine and the Medical Research Institute, Pusan National University, Busan 602-739 (Korea, Republic of)], E-mail: kimsuk@medigate.net; Lee, Jun Woo; Lee, Nam Kyung; Kim, Chang Won; Yi, Mi Seon [Department of Diagnostic Radiology, Pusan National University Hospital, Pusan National College of Medicine and the Medical Research Institute, Pusan National University, Busan 602-739 (Korea, Republic of); Kim, Gwang Ha; Kang, Dae Hwan [Division of Gastroenterology and Hepatology, Pusan National University Hospital, Pusan National College of Medicine and the Medical Research Institute, Pusan National University, Busan 602-739 (Korea, Republic of)

2009-08-15

There are widely diverse causes of pancreatitis. Gallstone and alcohol have been recognized as the most common causes of pancreatitis accounting for 90% of cases. However, acute and chronic pancreatitis may also result from a variety of uncommon causes. The determination of the etiology is important for patient management and prevention of recurrence. Sludge is the most common cause of idiopathic or recurrent acute pancreatitis. Endoscopic ultrasonography is considered as the most accurate diagnostic test for this abnormality. Computed tomography (CT) and magnetic resonance imaging (MRI) have only a limited role in the diagnosis of sludge. However, papillitis observed on the contrast-enhanced CT and MR may provide clues to the detection of pancreatitis secondary to sludge, a small stone or a recently passed stone. Radiological studies, clinical presentation and laboratory data can be helpful in determining the etiology of unusual causes of pancreatitis such as anatomic anomalies, autoimmune pancreatitis, groove pancreatitis, and traumatic pancreatitis.

Molecular imaging agents for SPECT (and SPECT/CT)

International Nuclear Information System (INIS)

Gnanasegaran, Gopinath; Ballinger, James R.

2014-01-01

The development of hybrid single photon emission computed tomography/computed tomography (SPECT/CT) cameras has increased the diagnostic value of many existing single photon radiopharmaceuticals. Precise anatomical localization of lesions greatly increases diagnostic confidence in bone imaging of the extremities, infection imaging, sentinel lymph node localization, and imaging in other areas. Accurate anatomical localization is particularly important prior to surgery, especially involving the parathyroid glands and sentinel lymph node procedures. SPECT/CT plays a role in characterization of lesions, particularly in bone scintigraphy and radioiodine imaging of metastatic thyroid cancer. In the development of novel tracers, SPECT/CT is particularly important in monitoring response to therapies that do not result in an early change in lesion size. Preclinical SPECT/CT devices, which actually have spatial resolution superior to PET/CT devices, have become essential in characterization of the biodistribution and tissue kinetics of novel tracers, allowing coregistration of serial studies within the same animals, which serves both to reduce biological variability and reduce the number of animals required. In conclusion, SPECT/CT increases the utility of existing radiopharmaceuticals and plays a pivotal role in the evaluation of novel tracers. (orig.)

Molecular imaging agents for SPECT (and SPECT/CT)

Energy Technology Data Exchange (ETDEWEB)

Gnanasegaran, Gopinath [Guy' s and St Thomas' NHS Foundation Trust, Department of Nuclear Medicine, London (United Kingdom); Ballinger, James R. [Guy' s and St Thomas' NHS Foundation Trust, Department of Nuclear Medicine, London (United Kingdom); King' s College London, Division of Imaging Sciences and Biomedical Engineering, London (United Kingdom)

2014-05-15

The development of hybrid single photon emission computed tomography/computed tomography (SPECT/CT) cameras has increased the diagnostic value of many existing single photon radiopharmaceuticals. Precise anatomical localization of lesions greatly increases diagnostic confidence in bone imaging of the extremities, infection imaging, sentinel lymph node localization, and imaging in other areas. Accurate anatomical localization is particularly important prior to surgery, especially involving the parathyroid glands and sentinel lymph node procedures. SPECT/CT plays a role in characterization of lesions, particularly in bone scintigraphy and radioiodine imaging of metastatic thyroid cancer. In the development of novel tracers, SPECT/CT is particularly important in monitoring response to therapies that do not result in an early change in lesion size. Preclinical SPECT/CT devices, which actually have spatial resolution superior to PET/CT devices, have become essential in characterization of the biodistribution and tissue kinetics of novel tracers, allowing coregistration of serial studies within the same animals, which serves both to reduce biological variability and reduce the number of animals required. In conclusion, SPECT/CT increases the utility of existing radiopharmaceuticals and plays a pivotal role in the evaluation of novel tracers. (orig.)

Clinical PET/CT Atlas: A Casebook of Imaging in Oncology

International Nuclear Information System (INIS)

2015-01-01

Integrated positron emission tomography/computed tomography (PET/CT) has evolved since its introduction into the commercial market more than a decade ago. It is now a key procedure, particularly in oncological imaging. Over the last years in routine clinical service, PET/CT has had a significant impact on diagnosis, treatment planning, staging, therapy, and monitoring of treatment response and has therefore played an important role in the care of cancer patients. The high sensitivity from the PET component and the specificity of the CT component give this hybrid imaging modality the unique characteristics that make PET/CT, even after over 10 years of clinical use, one of the fastest growing imaging modalities worldwide. This publication combines over 90 comprehensive cases covering all major indications of fluorodeoxyglucose (18F-FDG)-PET/CT as well as some cases of clinically relevant special tracers. The cases provide an overview of what the specific disease can look like in PET/CT, the typical pattern of the disease’s spread as well as likely pitfalls and teaching points. This PET/CT Atlas will allow professionals interested in PET/CT imaging to embrace the variety of oncological imaging by providing clinically relevant teaching files on the effectiveness and diagnostic quality of FDG-PET/CT imaging in routine applications

Source position error influence on industry CT image quality

International Nuclear Information System (INIS)

Cong Peng; Li Zhipeng; Wu Haifeng

2004-01-01

Based on the emulational exercise, the influence of source position error on industry CT (ICT) image quality was studied and the valuable parameters were obtained for the design of ICT. The vivid container CT image was also acquired from the CT testing system. (authors)

Realistic simulation of reduced-dose CT with noise modeling and sinogram synthesis using DICOM CT images

International Nuclear Information System (INIS)

Won Kim, Chang; Kim, Jong Hyo

2014-01-01

Purpose: Reducing the patient dose while maintaining the diagnostic image quality during CT exams is the subject of a growing number of studies, in which simulations of reduced-dose CT with patient data have been used as an effective technique when exploring the potential of various dose reduction techniques. Difficulties in accessing raw sinogram data, however, have restricted the use of this technique to a limited number of institutions. Here, we present a novel reduced-dose CT simulation technique which provides realistic low-dose images without the requirement of raw sinogram data. Methods: Two key characteristics of CT systems, the noise equivalent quanta (NEQ) and the algorithmic modulation transfer function (MTF), were measured for various combinations of object attenuation and tube currents by analyzing the noise power spectrum (NPS) of CT images obtained with a set of phantoms. Those measurements were used to develop a comprehensive CT noise model covering the reduced x-ray photon flux, object attenuation, system noise, and bow-tie filter, which was then employed to generate a simulated noise sinogram for the reduced-dose condition with the use of a synthetic sinogram generated from a reference CT image. The simulated noise sinogram was filtered with the algorithmic MTF and back-projected to create a noise CT image, which was then added to the reference CT image, finally providing a simulated reduced-dose CT image. The simulation performance was evaluated in terms of the degree of NPS similarity, the noise magnitude, the bow-tie filter effect, and the streak noise pattern at photon starvation sites with the set of phantom images. Results: The simulation results showed good agreement with actual low-dose CT images in terms of their visual appearance and in a quantitative evaluation test. The magnitude and shape of the NPS curves of the simulated low-dose images agreed well with those of real low-dose images, showing discrepancies of less than +/−3.2% in

Dynamic changes in the dural space and spinal cord cross-sectional area during flexion and extension in patients with cervical spondylotic myelopathy

International Nuclear Information System (INIS)

Machino, Masaaki; Yukawa, Yasutsugu; Ito, Keigo; Nakashima, Hiroaki; Kato, Fumihiko

2009-01-01

The number of patients with cervical spondylotic myelopathy (CSM) is increasing with the aging of the population. The patients' during spinal cord tends to be compressed neck extension, because the yellow ligaments and intervertebral discs protrude into the spinal canal during neck extension (pincer mechanism). A total of 100 patients with CSM were prospectively enrolled in this study. After preoperative myelography, multi-detector-row CT (MDCT) scans were acquired in flexion and extension, and the dural space and spinal cord cross-sectional area at each disc level from C2/3 to C7/Th1 were measured by using Scion imaging software. The average dural space and average spinal cord cross-sectional area were smaller in extension than in flexion from the C3/4 to C7/Th1 disc level, and the greatest dynamic changes were seen at the C5/6 level. MDCT demonstrated dynamic factors in patients with CSM. The spinal cord cross-sectional area became narrower during extension in patients with CSM. (author)

Development of high resolution x-ray CT technique for irradiated fuel assembly

Energy Technology Data Exchange (ETDEWEB)

Ishimi, Akihiro; Katsuyama, Kozo; Maeda, Koji; Asaga, Takeo [Japan Atomic Energy Agency, Oarai Research and Development Center, Oarai, Ibaraki (Japan)

2012-03-15

High X-ray CT technique was developed to observe the irradiation performance of FBR fuel assembly and MOX fuel. In this technique, the high energy X-ray pulse (12MeV) was used synchronizing detection system with the X-ray pulse to reduce the effect of the gamma ray emissions from the irradiated fuel assembly. In this study, this technique was upgraded to obtain high resolution X-ray CT image. In this upgrading, the collimator which had slit width of 0.1 mm and X-ray detector of a highly sensitive silicon semiconductor detector (100 channels) was introduced in the X-ray CT system. As a result of these developments, high resolution X-ray CT images could be obtained on the transverse cross section of irradiated fuel assembly. (author)

AP diameter shows the strongest correlation with CTDI and DLP in abdominal and chest CT.

LENUS (Irish Health Repository)

Zarb, Francis

2010-01-01

The purpose of this study is to investigate the relationships among cross-sectional diameters, weight and computed tomography (CT) dose descriptors (CTDI and DLP) to identify which is best used as a measure for the establishment of DRLs in CT. Data (gender, weight, cross-sectional diameters, dose descriptors) from 56 adult patients attending for either a CT examination of the abdomen or chest was obtained from two spiral CT units using automatic milliampere modulation. The AP diameter was demonstrated as the main contributing factor influencing the dose in CT (CTDI: r(2) = 0.269, p-value < or =0.001; DLP: r(2) = 0.260, p-value < or =0.001) since it has a greater correlation with radiation dose than body weight and can thus be its substitute in dose-reduction strategies and establishment of DRLs. The advantages of using the AP diameter are that it can easily be measured prior to scanning or retrospectively from previous CT images. However, further studies on the practicality of this approach are recommended.

Standard cross-section data

International Nuclear Information System (INIS)

Carlson, A.D.

1984-01-01

The accuracy of neutron cross-section measurement is limited by the uncertainty in the standard cross-section and the errors associated with using it. Any improvement in the standard immediately improves all cross-section measurements which have been made relative to that standard. Light element, capture and fission standards are discussed. (U.K.)

Use of the Uro Dyna-CT in endourology - the new frontier

Energy Technology Data Exchange (ETDEWEB)

Vicentini, Fabio C.; Botelho, Luiz A.A.; Braz, Jose L.M.; Almeida, Ernane de S.; Hisano, Marcelo, E-mail: fabio@drfabiovicentini.com.br [Hospital 9 de Julho, Sao Paulo, SP (Brazil)

2017-07-15

We describe the use of the Uro Dyna-CT, an imaging system used in the operating room that produces real-time three-dimensional (3D) imaging and cross-sectional image reconstructions similar to an intraoperative computerized tomography, during a percutaneous nephrolithotomy and a contralateral flexible ureteroscopy in a complete supine position. A 65 year-old female patient had an incomplete calyceal staghorn stone in the right kidney and a 10mm in the left one. The procedure was uneventful and the intraoperative use of the Uro Dyna-CT identified 2 residual stones that were not found by digital fluoroscopy and flexible nephroscopy at the end of surgery, helping to render the patient stone-free in one procedure, which was confirmed by a postoperative CT scan. Prospective studies will define the real role of the Uro Dyna-CT for endourological procedures, but its use seems to be a very promising tool for improving stone free rates and decreasing auxiliary procedures, especially for complex cases. (author)

MO-DE-207A-09: Low-Dose CT Image Reconstruction Via Learning From Different Patient Normal-Dose Images

Energy Technology Data Exchange (ETDEWEB)

Han, H; Xing, L [Stanford University, Palo Alto, CA (United States); Liang, Z [Stony Brook University, Stony Brook, NY (United States)

2016-06-15

Purpose: To investigate a novel low-dose CT (LdCT) image reconstruction strategy for lung CT imaging in radiation therapy. Methods: The proposed approach consists of four steps: (1) use the traditional filtered back-projection (FBP) method to reconstruct the LdCT image; (2) calculate structure similarity (SSIM) index between the FBP-reconstructed LdCT image and a set of normal-dose CT (NdCT) images, and select the NdCT image with the highest SSIM as the learning source; (3) segment the NdCT source image into lung and outside tissue regions via simple thresholding, and adopt multiple linear regression to learn high-order Markov random field (MRF) pattern for each tissue region in the NdCT source image; (4) segment the FBP-reconstructed LdCT image into lung and outside regions as well, and apply the learnt MRF prior in each tissue region for statistical iterative reconstruction of the LdCT image following the penalized weighted least squares (PWLS) framework. Quantitative evaluation of the reconstructed images was based on the signal-to-noise ratio (SNR), local binary pattern (LBP) and histogram of oriented gradients (HOG) metrics. Results: It was observed that lung and outside tissue regions have different MRF patterns predicted from the NdCT. Visual inspection showed that our method obviously outperformed the traditional FBP method. Comparing with the region-smoothing PWLS method, our method has, in average, 13% increase in SNR, 15% decrease in LBP difference, and 12% decrease in HOG difference from reference standard for all regions of interest, which indicated the superior performance of the proposed method in terms of image resolution and texture preservation. Conclusion: We proposed a novel LdCT image reconstruction method by learning similar image characteristics from a set of NdCT images, and the to-be-learnt NdCT image does not need to be scans from the same subject. This approach is particularly important for enhancing image quality in radiation therapy.

MO-DE-207A-09: Low-Dose CT Image Reconstruction Via Learning From Different Patient Normal-Dose Images

International Nuclear Information System (INIS)

Han, H; Xing, L; Liang, Z

2016-01-01

Purpose: To investigate a novel low-dose CT (LdCT) image reconstruction strategy for lung CT imaging in radiation therapy. Methods: The proposed approach consists of four steps: (1) use the traditional filtered back-projection (FBP) method to reconstruct the LdCT image; (2) calculate structure similarity (SSIM) index between the FBP-reconstructed LdCT image and a set of normal-dose CT (NdCT) images, and select the NdCT image with the highest SSIM as the learning source; (3) segment the NdCT source image into lung and outside tissue regions via simple thresholding, and adopt multiple linear regression to learn high-order Markov random field (MRF) pattern for each tissue region in the NdCT source image; (4) segment the FBP-reconstructed LdCT image into lung and outside regions as well, and apply the learnt MRF prior in each tissue region for statistical iterative reconstruction of the LdCT image following the penalized weighted least squares (PWLS) framework. Quantitative evaluation of the reconstructed images was based on the signal-to-noise ratio (SNR), local binary pattern (LBP) and histogram of oriented gradients (HOG) metrics. Results: It was observed that lung and outside tissue regions have different MRF patterns predicted from the NdCT. Visual inspection showed that our method obviously outperformed the traditional FBP method. Comparing with the region-smoothing PWLS method, our method has, in average, 13% increase in SNR, 15% decrease in LBP difference, and 12% decrease in HOG difference from reference standard for all regions of interest, which indicated the superior performance of the proposed method in terms of image resolution and texture preservation. Conclusion: We proposed a novel LdCT image reconstruction method by learning similar image characteristics from a set of NdCT images, and the to-be-learnt NdCT image does not need to be scans from the same subject. This approach is particularly important for enhancing image quality in radiation therapy.

Reaction cross section calculation of some alkaline earth elements

Science.gov (United States)

Tel, Eyyup; Kavun, Yusuf; Sarpün, Ismail Hakki

2017-09-01

Reaction cross section knowledge is crucial to application nuclear physics such as medical imaging, radiation shielding and material evaluations. Nuclear reaction codes can be used if the experimental data are unavailable or are improbably to be produced because of the experimental trouble. In this study, there action cross sections of some target alkaline earth elements have been calculated by using pre-equilibrium and equilibrium nuclear reaction models for nucleon induced reactions. While these calculations, the Hybrid Model, the Geometry Dependent Hybrid Model, the Full Exciton Model, the Cascade Exciton Model for pre-equilibrium reactions and the Weisskopf-Ewing Model for equilibrium reactions have been used. The calculated cross sections have been discussed and compared with the experimental data taken from Experimental Nuclear Reaction Data library.

PET/CT imaging: The incremental value of assessing the glucose metabolic phenotype and the structure of cancers in a single examination

International Nuclear Information System (INIS)

Czernin, Johannes; Benz, Matthias R.; Allen-Auerbach, Martin S.

2010-01-01

PET/CT with the glucose analogue FDG is emerging as the most important diagnostic imaging tool in oncology. More than 2000 PET/CT scanners are operational worldwide and its unique role for diagnosing, staging, restaging and therapeutic monitoring in cancer is undisputed. Studies conducted in thousands of cancer patients have clearly indicated that the combination of molecular PET with anatomical CT imaging provides incremental diagnostic value over PET or CT alone. State of the art imaging protocols combine fully diagnostic CT scans with quality whole body PET surveys. The current review briefly describes the biological alterations of cancer cells that result in their switch to a strongly glycolytic phenotype. Different whole body imaging protocols are discussed. We summarize the evidence for the incremental value of PET/CT over CT and PET alone using imaging of sarcoma as an example. Following this section we discuss the performance of FDG-PET/CT imaging for staging, restaging and monitoring of head and neck cancer, solitary lung nodules and lung cancer, breast cancer, colorectal cancer, lymphoma and unknown primary tumors. Finally, the recently emerging evidence of a substantial impact of PET/CT imaging on patient management is presented.

Imaging fusion (SPECT/CT) in degenerative disease of spine

International Nuclear Information System (INIS)

Bernal, P.; Ucros, G.; Bermudez, S.; Ocampo, M.

2007-01-01

Full text: Objective: To determine the utility of Fusion Imaging SPECT/CT in degenerative pathology of the spine and to establish the impact of the use of fusion imaging in spinal pain due to degenerative changes of the spine. Materials and methods: 44 Patients (M=21, F=23) average age of 63 years and with degenerative pathology of spine were sent to Diagnosis Imaging department in FSFB. Bone scintigraphy (SPECT), CT of spine (cervical: 30%, Lumbar 70%) and fusion imaging were performed in all of them. Bone scintigraphy was carried out in a gamma camera Siemens Diacam double head attached to ESOFT computer. The images were acquired in matrix 128 x 128, 20 seg/imag, 64 images. CT of spine was performed same day or two days after in Helycoidal Siemens somatom emotion CT. The fusion was done in a Dicom workstation in sagital, axial and coronal reconstruction. The findings were evaluated by 2 Nuclear Medicine physicians and 2 radiologists of the staff of FSFB in an independent way. Results: Bone scan (SPECT) and CT of 44 patients were evaluated. CT showed facet joint osteoarthrities in 27 (61.3%) patients, uncovertebral joint arthrosis in 7 (15.9%), bulging disc in 9(20.4%), spinal nucleus lesion in 7(15.9%), osteophytes in 9 (20.4%), spinal foraminal stenosis in 7 (15.9%), spondylolysis/spondylolisthesis in 4 (9%). Bone scan showed facet joint osteoarthrities in 29 (65.9%), uncovertebral joint arthrosis in 4 (9%), osteophytes in 9 (20.4%) and normal 3 (6.8%). The imaging fusion showed coincidence findings (main lesion in CT with high uptake in scintigraphy) in 34 patients (77.2%) and no coincidence in 10 (22.8%). In 15 (34.09%) patients the fusion provided additional information. The analysis of the findings of CT and SPECT showed similar results in most of the cases and the fusion didn't provide additional information but it allowed to confirm the findings but when the findings didn't match where the CT showed several findings and SPECT only one area with high uptake

Determination of optimal parameters for three-dimensional reconstruction images of central airways using helical CT

International Nuclear Information System (INIS)

Hirose, Takahumi; Akata, Soichi; Matsuno, Naoto; Nagao, Takeshi; Abe, Kimihiko

2002-01-01

Three-dimensional (3D) image reconstruction of central airways using helical CT requires several user-defined parameters that exceed the requirements of conventional CT. The purpose of this study was to evaluate the optimal parameters for 3D images of central airways using helical CT. In our experimental study using a piglet immediately after sacrifice, 3D images of the central airway were evaluated with changes of 3D imaging parameters, such as detector collimation (1, 2, 3 and 6 mm), table speed (1, 2, 3 and 5 mm/sec), tube electric current (50, 100, 150, 200 and 250 mA), reconstruction interval (0.3, 0.5, 1, 2 and 3 mm), algorithm (mediastinum and lung) and interpolation method (180 deg and 360 deg). To minimize detector collimation, table speed, and reconstruction interval could provide the best 3D images of the central airway. Stair-step artifacts could also be reduced with a slow table speed. However, decreasing the collimation and table speed decreases not only the effective section thickness but also the scan coverage that can be achieved with a helical CT. For routine diagnosis, we conclude that optimal parameters for 3D images of the central airway are to minimize the table speed necessary to cover the volume of interest and to set detector collimation to 1/2 of the table speed. The reconstruction intervals should also be selected at up to 1/2 of the detector collimation, but with trade-offs of increased image processing time, data storage requirements, and physician time for image review. Regarding to tube electric current, 200 mA or more was necessary. Pixel noise increased with the algorithm for the lung. The 180 deg interpolation is better than 360 deg interpolation due to thin effective section thickness. (author)

Molecular Imaging with Small Animal PET/CT

DEFF Research Database (Denmark)

Binderup, T.; El-Ali, H.H.; Skovgaard, D.

2011-01-01