CT and MRI of the epigastrium - is the MRI competitive?

International Nuclear Information System (INIS)

Hamm, B. von

1993-01-01

The conclusion drawn in this article is: - CT will continue to rank first as a method for diagnostic evaluation of the entire abdomen. - MRI now offers advantages over CT for diagnostic identification of focal liver lesions, both with regard to detection as such and to a differential diagnosis of liver tumors. - CT continues to be the modality of first choice for diagnostic evaluation of acute pancreatitis. - CT offers advantages for the diagnostic evaluation of the gastrointestinal tract (as e.g. in case of complications in the course of inflammatory intestinal affection). - Interventional measures such as biopsies or abscess drainage will still be best controlled by CT, and MRI is not likely to become a really competitive method for such tasks in the foreseeable future. (orig.) [de

CT and MRI diagnosis of nasopharyneal angiofibroma

International Nuclear Information System (INIS)

Zhang Xiaoya; Liang Biling

2007-01-01

Objective: To analyze the CT and MRI manifestations of nasopharyneal angiofibroma. Methods: 21 cases of nasopharyneal angiofibroma are retrospectively analyzed according to the location, size, margin, density or signal of the tumor and the changes of surrounding bones. Results: The CT and MRI showed a nasopharyneal mass with well-defined margin, uniform density or signal and remarkably enhanced. The sphenomaxillary fossa was enlarged and the posterior wall of maxillary sinus was, compressed and displaced without bone destruction. The surrounding bone appeared to be compressed, molded, absorbed or destroyed. Conclusion: CT examination can usually provide diagnostic information, but the combination of CT and MRI can be better contributed to the diagnosis, location and stage classification of nasopharyneal angiofbroma. (authors)

CT and MRI of vertebral haemangiomas

International Nuclear Information System (INIS)

Braitinger, S.; Weigert, F.; Held, P.; Obletter, N.; Breit, A.

1989-01-01

A retrospective comparative study of CT and MRI was carried out involving 38 vertebral haemangiomas; this revealed a typical signal pattern on MRI from benign lesions. It consists of a hyper-intense signal from the bone marrow affecting the T 1 /T 2 sequences; this may be focal or involve the entire vertebral body. These characteristic signals were compared with CT images of the spine. The areas of bone that produce the high intensity signals on MRI appear on CT as spongey patterns with hypertrophic trabeculae surrounding mostly areas with negative absorption values. An analysis of the changes in the spongiosa has revealed three clearly defined types. The signals derived from haemangiomas extending beyond the bone have an intensity of normal spongiosa; this corresponds with an absence of fat, as demonstrated by CT. Extra-osseous components have low intensity T 1 signals that increase in T 2 sequences. (orig.) [de

Comparison of SPECT/CT, MRI and CT in diagnosis of skull base bone invasion in nasopharyngeal carcinoma.

Science.gov (United States)

Zhang, Shu-xu; Han, Peng-hui; Zhang, Guo-qian; Wang, Rui-hao; Ge, Yong-bin; Ren, Zhi-gang; Li, Jian-sheng; Fu, Wen-hai

2014-01-01

Early detection of skull base invasion in nasopharyngeal carcinoma (NPC) is crucial for correct staging, assessing treatment response and contouring the tumor target in radiotherapy planning, as well as improving the patient's prognosis. To compare the diagnostic efficacy of single photon emission computed tomography/computed tomography (SPECT/CT) imaging, magnetic resonance imaging (MRI) and computed tomography (CT) for the detection of skull base invasion in NPC. Sixty untreated patients with histologically proven NPC underwent SPECT/CT imaging, contrast-enhanced MRI and CT. Of the 60 patients, 30 had skull base invasion confirmed by the final results of contrast-enhanced MRI, CT and six-month follow-up imaging (MRI and CT). The diagnostic efficacy of the three imaging modalities in detecting skull base invasion was evaluated. The rates of positive findings of skull base invasion for SPECT/CT, MRI and CT were 53.3%, 48.3% and 33.3%, respectively. The sensitivity, specificity and accuracy were 93.3%, 86.7% and 90.0% for SPECT/CT fusion imaging, 96.7%, 100.0% and 98.3% for contrast-enhanced MRI, and 66.7%, 100.0% and 83.3% for contrast-enhanced CT. MRI showed the best performance for the diagnosis of skull base invasion in nasopharyngeal carcinoma, followed closely by SPECT/CT. SPECT/CT had poorer specificity than that of both MRI and CT, while CT had the lowest sensitivity.

MRI and CT findings of intracranial neurosyphilis

International Nuclear Information System (INIS)

Suh, Hong Kil; Shim, Ya Seong; Kim, Seon Bok; Kim, Uk Jung; Lee, Shin Ho; Jung, Hae Kyuong; Lee, Eil Seong; Kang, Ik Won; Cho, Hyeun Cha

1999-01-01

To evaluate the CT and MRI findings of neurosyphilis. We retrospectively reviewed the CT and MR imaging findings in five patients with intracranial neurosyphilis confirmed by CSF, VDRL, TPHA, and clinical follow-up. MR imaging was performed in all five cases, and CT in two. The MRI and CT findings of intracranial neurosyphilis included infarction (n=3), focal inflammation (n=1) and encephalopathy (n=1). There was a total of ten infaretions : three of the basal ganglia, two each of the frontal lobe, watershed zone, and cerebellum, and one of the occipital lobe. Intaretion was most common in MCA territory (n=9; 50%), followed by the watershed zone (16.6%), posterior cerebral artery territory (16.6%), and posterior inferior cerebellar artery territory (11.1%). The size of the lesion varied from 1cm to larger than one lobe. One patient showed diffuse high signal intensity in the left temporal lobe, but on follow-up MRI, this had resolved. The most common finding of neurosyphilis, as seen on MRI and CT, was infarction in middle cerebral arterial territory

MRI and CT findings of intracranial neurosyphilis

Energy Technology Data Exchange (ETDEWEB)

Suh, Hong Kil; Shim, Ya Seong; Kim, Seon Bok; Kim, Uk Jung; Lee, Shin Ho; Jung, Hae Kyuong; Lee, Eil Seong; Kang, Ik Won [Hallym University College of Medicine, Seoul (Korea, Republic of); Cho, Hyeun Cha [Sungkyunkwan University College of Medicine, Seoul (Korea, Republic of)

1999-02-01

To evaluate the CT and MRI findings of neurosyphilis. We retrospectively reviewed the CT and MR imaging findings in five patients with intracranial neurosyphilis confirmed by CSF, VDRL, TPHA, and clinical follow-up. MR imaging was performed in all five cases, and CT in two. The MRI and CT findings of intracranial neurosyphilis included infarction (n=3), focal inflammation (n=1) and encephalopathy (n=1). There was a total of ten infaretions : three of the basal ganglia, two each of the frontal lobe, watershed zone, and cerebellum, and one of the occipital lobe. Intaretion was most common in MCA territory (n=9; 50%), followed by the watershed zone (16.6%), posterior cerebral artery territory (16.6%), and posterior inferior cerebellar artery territory (11.1%). The size of the lesion varied from 1cm to larger than one lobe. One patient showed diffuse high signal intensity in the left temporal lobe, but on follow-up MRI, this had resolved. The most common finding of neurosyphilis, as seen on MRI and CT, was infarction in middle cerebral arterial territory.

MRI and CT in alveolar echinococcosis of the liver

International Nuclear Information System (INIS)

Duewell, S.; Marincek, B.; Schulthess, G.K. von; Ammann, R.; Zurich Univ.

1990-01-01

To compare the value of MRI and CT in evaluating hepatic alveolar echinococcosis a study was conducted on 30 patients. The liver was initially affected in all patients. At the time of examination, 15 patients had undergone partial liver resection. MRI showed no advantage over CT in demonstrating an echinococcal mass lesion. MRI was superior in identifying concomitant pathological changes of the intrahepatic and extrahepatic venous system due to the intrinsic contrast of vascular structures. However, CT was superior in identifying calcifications, an important attribute of the disease. MRI should only be used in imaging alveolar echinococcosis of the liver if diagnostic questions remain open after CT, in particular questions concerning venous pathology. MRI may also be used to replace CT in patients with a contraindication to urographic contrast material. (orig.) [de

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

Juvenile spondylolysis: a comparative analysis of CT, SPECT and MRI

International Nuclear Information System (INIS)

Campbell, R.S.D.; Grainger, A.J.; Hide, I.G.; Papastefanou, S.; Greenough, C.G.

2005-01-01

To evaluate whether MRI correlates with CT and SPECT imaging for the diagnosis of juvenile spondylolysis, and to determine whether MRI can be used as an exclusive image modality. Juveniles and young adults with a history of extension low back pain were evaluated by MRI, CT and SPECT imaging. All images were reviewed blindly. Correlative analyses included CT vs MRI for morphological grading and SPECT vs MRI for functional grading. Finally, an overall grading system compared MRI vs CT and SPECT combined. Statistical analysis was performed using the kappa statistic. Seventy-two patients (mean age 16 years) were recruited. Forty pars defects were identified in 22 patients (31%), of which 25 were chronic non-union, five acute complete defects and ten acute incomplete fractures. Kappa scores demonstrated a high level of agreement for all comparative analyses. MRI vs SPECT (kappa: 0.794), MRI vs CT (kappa: 0.829) and MRI vs CT/SPECT (kappa: 0.786). The main causes of discrepancy were between MRI and SPECT for the diagnosis of stress reaction in the absence of overt fracture, and distinguishing incomplete fractures from intact pars or complete defects. MRI can be used as an effective and reliable first-line image modality for diagnosis of juvenile spondylolysis. However, localised CT is recommended as a supplementary examination in selected cases as a baseline for assessment of healing and for evaluation of indeterminate cases. (orig.)

Juvenile spondylolysis: a comparative analysis of CT, SPECT and MRI

Energy Technology Data Exchange (ETDEWEB)

Campbell, R.S.D. [Royal Liverpool University Hospital, Department of Radiology, Liverpool (United Kingdom); Grainger, A.J. [Leeds General Infirmary, Department of Radiology, Leeds (United Kingdom); Hide, I.G. [Freeman Hospital, Department of Radiology, Newcastle upon Tyne (United Kingdom); Papastefanou, S. [James Cook University Hospital, Department Radiology, Middlesbrough (United Kingdom); Greenough, C.G. [James Cook University Hospital, Department of Trauma and Orthopaedics, Middlesbrough (United Kingdom)

2005-02-01

To evaluate whether MRI correlates with CT and SPECT imaging for the diagnosis of juvenile spondylolysis, and to determine whether MRI can be used as an exclusive image modality. Juveniles and young adults with a history of extension low back pain were evaluated by MRI, CT and SPECT imaging. All images were reviewed blindly. Correlative analyses included CT vs MRI for morphological grading and SPECT vs MRI for functional grading. Finally, an overall grading system compared MRI vs CT and SPECT combined. Statistical analysis was performed using the kappa statistic. Seventy-two patients (mean age 16 years) were recruited. Forty pars defects were identified in 22 patients (31%), of which 25 were chronic non-union, five acute complete defects and ten acute incomplete fractures. Kappa scores demonstrated a high level of agreement for all comparative analyses. MRI vs SPECT (kappa: 0.794), MRI vs CT (kappa: 0.829) and MRI vs CT/SPECT (kappa: 0.786). The main causes of discrepancy were between MRI and SPECT for the diagnosis of stress reaction in the absence of overt fracture, and distinguishing incomplete fractures from intact pars or complete defects. MRI can be used as an effective and reliable first-line image modality for diagnosis of juvenile spondylolysis. However, localised CT is recommended as a supplementary examination in selected cases as a baseline for assessment of healing and for evaluation of indeterminate cases. (orig.)

A MRI-CT prostate registration using sparse representation technique

Science.gov (United States)

Yang, Xiaofeng; Jani, Ashesh B.; Rossi, Peter J.; Mao, Hui; Curran, Walter J.; Liu, Tian

2016-03-01

Purpose: To develop a new MRI-CT prostate registration using patch-based deformation prediction framework to improve MRI-guided prostate radiotherapy by incorporating multiparametric MRI into planning CT images. Methods: The main contribution is to estimate the deformation between prostate MRI and CT images in a patch-wise fashion by using the sparse representation technique. We assume that two image patches should follow the same deformation if their patch-wise appearance patterns are similar. Specifically, there are two stages in our proposed framework, i.e., the training stage and the application stage. In the training stage, each prostate MR images are carefully registered to the corresponding CT images and all training MR and CT images are carefully registered to a selected CT template. Thus, we obtain the dense deformation field for each training MR and CT image. In the application stage, for registering a new subject MR image with the same subject CT image, we first select a small number of key points at the distinctive regions of this subject CT image. Then, for each key point in the subject CT image, we extract the image patch, centered at the underlying key point. Then, we adaptively construct the coupled dictionary for the underlying point where each atom in the dictionary consists of image patches and the respective deformations obtained from training pair-wise MRI-CT images. Next, the subject image patch can be sparsely represented by a linear combination of training image patches in the dictionary, where we apply the same sparse coefficients to the respective deformations in the dictionary to predict the deformation for the subject MR image patch. After we repeat the same procedure for each subject CT key point, we use B-splines to interpolate a dense deformation field, which is used as the initialization to allow the registration algorithm estimating the remaining small segment of deformations from MRI to CT image. Results: Our MRI-CT registration

Practical textbook of cardiac CT and MRI

Energy Technology Data Exchange (ETDEWEB)

Lim, Tae-Hwan (ed.) [ASAN Medical Center, Seoul (Korea, Republic of). Dept. of Radiology

2015-04-01

Guide to the interpretation of cardiac CT and MRI for the purposes of diagnosis, treatment planning, and follow-up. Emphasis on applications in a wide range of real clinical situations. Numerous informative illustrations. Summarizing sections permitting rapid retrieval of information. QR codes allowing access to references, additional figures, and motion pictures from the internet. This up-to-date textbook comprehensively reviews all aspects of cardiac CT and MRI and demonstrates the value of these techniques in clinical practice. A wide range of applications are considered, including imaging of atherosclerotic and non-atherosclerotic coronary artery disease, coronary revascularization, ischemic heart disease, non-ischemic cardiomyopathy, valvular heart disease, cardiac tumors, and pericardial disease. The numerous high-quality images illustrate how to interpret cardiac CT and MRI correctly for the purposes of diagnosis, treatment planning, and follow-up. Helpful summarizing sections in every chapter will facilitate rapid retrieval of information. This book will be of great value to radiologists and cardiologists seeking a reliable guide to the optimal use of cardiac CT and MRI in real clinical situations.

Paranasal sinuses and nasopharynx CT and MRI

International Nuclear Information System (INIS)

Sievers, K.W.; Greess, H.; Baum, U.; Dobritz, M.; Lenz, M.

2000-01-01

Neoplastic disease of the nose, paranasal sinuses, the nasopharynx and the parapharyngeal space requires thorough assessment of location and extent in order to plan appropriate treatment. CT allows the deep soft tissue planes to be evaluated and provides a complement to the physical examination. It is especially helpful in regions involving thin bony structures (paranasal sinuses, orbita); here CT performs better than MRI. MRI possesses many advantages over other imaging modalities caused by its excellent tissue contrast. In evaluating regions involving predominantly soft tissue structures (ec nasopharynx and parapharyngeal space) MRI is superior to CT. The possibility to obtain strictly consecutive volume data sets with spiral CT or 3D MRI offer excellent perspectives to visualize the data via 2D or 3D postprocessing. Because head and neck tumors reside in a complex area, having a 3D model of the anatomical features may assist in the delineation of pathology. Data sets may be transferred directly into computer systems and thus be used in computer assisted surgery

Paranasal sinuses and nasopharynx CT and MRI.

Science.gov (United States)

Sievers, K W; Greess, H; Baum, U; Dobritz, M; Lenz, M

2000-03-01

Neoplastic disease of the nose, paranasal sinuses, the nasopharynx and the parapharyngeal space requires thorough assessment of location and extent in order to plan appropriate treatment. CT allows the deep soft tissue planes to be evaluated and provides a complement to the physical examination. It is especially helpful in regions involving thin bony structures (paranasal sinuses, orbita); here CT performs better than MRI. MRI possesses many advantages over other imaging modalities caused by its excellent tissue contrast. In evaluating regions involving predominantly soft tissue structures (ec nasopharynx and parapharyngeal space) MRI is superior to CT. The possibility to obtain strictly consecutive volume data sets with spiral CT or 3D MRI offer excellent perspectives to visualize the data via 2D or 3D postprocessing. Because head and neck tumors reside in a complex area, having a 3D model of the anatomical features may assist in the delineation of pathology. Data sets may be transferred directly into computer systems and thus be used in computer assisted surgery.

Practical textbook of cardiac CT and MRI

International Nuclear Information System (INIS)

Lim, Tae-Hwan

2015-01-01

Guide to the interpretation of cardiac CT and MRI for the purposes of diagnosis, treatment planning, and follow-up. Emphasis on applications in a wide range of real clinical situations. Numerous informative illustrations. Summarizing sections permitting rapid retrieval of information. QR codes allowing access to references, additional figures, and motion pictures from the internet. This up-to-date textbook comprehensively reviews all aspects of cardiac CT and MRI and demonstrates the value of these techniques in clinical practice. A wide range of applications are considered, including imaging of atherosclerotic and non-atherosclerotic coronary artery disease, coronary revascularization, ischemic heart disease, non-ischemic cardiomyopathy, valvular heart disease, cardiac tumors, and pericardial disease. The numerous high-quality images illustrate how to interpret cardiac CT and MRI correctly for the purposes of diagnosis, treatment planning, and follow-up. Helpful summarizing sections in every chapter will facilitate rapid retrieval of information. This book will be of great value to radiologists and cardiologists seeking a reliable guide to the optimal use of cardiac CT and MRI in real clinical situations.

Experimental bacterial meningitis in rabbit; evaluation with CT and MRI

Energy Technology Data Exchange (ETDEWEB)

Seo, Jeong Jin; Kang, Heoung Keun; Chu, Sung Nam; Kim, Yun Hyeon; Jeong, Yong Yeon; Chung, Hyon De [Chonnam Univ. Medical School, Kwangju (Korea, Republic of)

1996-01-01

The purpose of this study was to evaluate the usefulness of computed tomography(CT) and magnetic resonance imaging(MRI) in experimental bacterial meningitis. CT and MR images of experimental bacterial meningitis were obtained after inoculation of 1ml suspension of 10-6/ml Staphylococcus aureus directly into the supratentorial arachnoid space of 18 New Zealand white rabbits. Each animal was studied with both pre-enhanced and post-enhanced CT and MRI at 12, 24, 48 hours and 1 week. Cerebrospinal fluid of all of 18 rabbits were sampled and cultured for bacterial growth. All of 18 rabbits had the clinical symptoms such as neck stiffness and anorexia within 24 hours after the inoculation. Cerebrospinal fluid cultures were positive for Staphylococcus aureus growth. Gd-enhanced MRI exhibited diffuse enhancement along the thickened supratentorial meninges earlier than CT. In Gd-enhanced MRI, the mean contrast enhancement along the thickened supratentorial meninges earlier than CT. In Gd-enhanced MRI, the mean contrast enhancement ratio(CER) at supratentorial meninges increased to 1.93 at 12 hours and 2.99 at 24 hours from 1.06 at 0 hour. Histologic evaluation demonstrated inflammatory cell infiltration into the meninges. MRI also identified the complications of meningitis such as ependymitis and hydrocephalus more effectively than CT. These results indicated that Fd-enhanced MRI detectred earlier the abnormal findingfs of bacterial meningitis and evaluated more effectively the complications of meningitis compared with CT. MRI was more useful than CT in evaluation of the bacterial meningitis.

Experimental bacterial meningitis in rabbit; evaluation with CT and MRI

International Nuclear Information System (INIS)

Seo, Jeong Jin; Kang, Heoung Keun; Chu, Sung Nam; Kim, Yun Hyeon; Jeong, Yong Yeon; Chung, Hyon De

1996-01-01

The purpose of this study was to evaluate the usefulness of computed tomography(CT) and magnetic resonance imaging(MRI) in experimental bacterial meningitis. CT and MR images of experimental bacterial meningitis were obtained after inoculation of 1ml suspension of 10-6/ml Staphylococcus aureus directly into the supratentorial arachnoid space of 18 New Zealand white rabbits. Each animal was studied with both pre-enhanced and post-enhanced CT and MRI at 12, 24, 48 hours and 1 week. Cerebrospinal fluid of all of 18 rabbits were sampled and cultured for bacterial growth. All of 18 rabbits had the clinical symptoms such as neck stiffness and anorexia within 24 hours after the inoculation. Cerebrospinal fluid cultures were positive for Staphylococcus aureus growth. Gd-enhanced MRI exhibited diffuse enhancement along the thickened supratentorial meninges earlier than CT. In Gd-enhanced MRI, the mean contrast enhancement along the thickened supratentorial meninges earlier than CT. In Gd-enhanced MRI, the mean contrast enhancement ratio(CER) at supratentorial meninges increased to 1.93 at 12 hours and 2.99 at 24 hours from 1.06 at 0 hour. Histologic evaluation demonstrated inflammatory cell infiltration into the meninges. MRI also identified the complications of meningitis such as ependymitis and hydrocephalus more effectively than CT. These results indicated that Fd-enhanced MRI detectred earlier the abnormal findingfs of bacterial meningitis and evaluated more effectively the complications of meningitis compared with CT. MRI was more useful than CT in evaluation of the bacterial meningitis

CT, MRI, and FDG PET/CT findings of sinonasal sarcoma: Differentiation from squamous cell carcinoma

International Nuclear Information System (INIS)

Kim, Jin Ho; Yoon, Dae Young; Baek, Sora; Park, Min Woo; Kwon, Kee Hwan; Rho, Young Soo

2016-01-01

To evaluate computed tomography (CT), magnetic resonance imaging (MRI), and 18F-fluorodeoxyglucose (FDG) positron emission tomography/CT (PET/CT) findings for the differentiation of sinonasal sarcoma from squamous cell carcinoma (SCC). We retrospectively reviewed CT, MRI, and FDG PET/CT results in 20 patients with pathologically proven sinonasal sarcoma (n = 7) and SCC (n = 13). Imaging characteristics of tumors, such as the shape, size, margin, MRI signal intensity, pattern of enhancement, local tumor invasion, and maximum standardized uptake value (SUVmax) were analyzed and compared between sarcoma and SCC. The SUVmax of sarcomas (7.4 ± 2.1) was significantly lower than the SUVmax of the SCCs (14.3 ± 4.5) (p = 0.0013). However, no significant difference in the shape, size, margin, MRI signal intensity, pattern of enhancement, and local tumor invasion was observed between sarcoma and SCC. Although CT and MR imaging features are nonspecific, FDG PET/CT is useful in distinguishing between sinonasal sarcoma and SCC based on the SUVmax value

CT, MRI, and FDG PET/CT findings of sinonasal sarcoma: Differentiation from squamous cell carcinoma

Energy Technology Data Exchange (ETDEWEB)

Kim, Jin Ho; Yoon, Dae Young; Baek, Sora; Park, Min Woo; Kwon, Kee Hwan; Rho, Young Soo [Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul (Korea, Republic of)

2016-07-15

To evaluate computed tomography (CT), magnetic resonance imaging (MRI), and 18F-fluorodeoxyglucose (FDG) positron emission tomography/CT (PET/CT) findings for the differentiation of sinonasal sarcoma from squamous cell carcinoma (SCC). We retrospectively reviewed CT, MRI, and FDG PET/CT results in 20 patients with pathologically proven sinonasal sarcoma (n = 7) and SCC (n = 13). Imaging characteristics of tumors, such as the shape, size, margin, MRI signal intensity, pattern of enhancement, local tumor invasion, and maximum standardized uptake value (SUVmax) were analyzed and compared between sarcoma and SCC. The SUVmax of sarcomas (7.4 ± 2.1) was significantly lower than the SUVmax of the SCCs (14.3 ± 4.5) (p = 0.0013). However, no significant difference in the shape, size, margin, MRI signal intensity, pattern of enhancement, and local tumor invasion was observed between sarcoma and SCC. Although CT and MR imaging features are nonspecific, FDG PET/CT is useful in distinguishing between sinonasal sarcoma and SCC based on the SUVmax value.

Serial high resolution CT in non-specific interstitial pneumonia: prognostic value of the initial pattern

Energy Technology Data Exchange (ETDEWEB)

Screaton, N.J. [Department of Radiology, Addenbrooke' s Hospital, Cambridge (United Kingdom)]. E-mail: nicholas.screaton@papworth.nhs.uk; Hiorns, M.P. [Department of Radiology, Great Ormond Street Hospital, London (United Kingdom); Lee, K.S. [Samsung Medical Centre, Seoul (Korea); Franquet, T. [Hospital de Saint Pau, Universidad Autonoma de Barcelona, Barcelona (Spain); Johkoh, T. [Department of Medical Physics and Radiology, Osaka University Graduate School of Medicine, Osaka (Japan); Fujimoto, K. [Department of Radiology, Kurume University School of Medicine, Kurume (Japan); Ichikado, K. [First Department of Internal Medicine, Kumamoto University School of Medicine, Kumamoto (Japan); Colby, T.V. [Department of Laboratory Medicine/Pathology, Mayo Clinic Scottsdale, AZ (United States); Mueller, N.L. [Department of Radiology, Vancouver General Hospital, Vancouver (Canada)

2005-01-01

AIM: To assess the relationship between initial CT pattern and serial changes in CT findings and pulmonary function tests (PFTs) in patients with non-specific interstitial pneumonia (NSIP). MATERIALS AND METHODS: Serial high resolution (HR) CTs and PFTs were retrospectively analyzed in 38 cases of histologically proven NSIP, including 4 with cellular NSIP, 13 with mixed cellular and fibrotic NSIP, and 21 with fibrotic NSIP. The presence and extent of various CT findings were assessed. A fibrosis index (defined as the ratio of the extent of a reticular/honeycomb pattern to the overall extent of abnormal parenchyma) was derived. RESULTS: The predominant CT pattern was reticular/honeycomb in 27 (84%) cases and ground-glass/consolidation in 6 (16%) cases. Between scans, mean disease extent reduced by 5.2%. Disease extent reduced by >10% in 13 (34%) and increased by >10% in 6 (16%) patients. Histopathological subtype of NSIP did not correlate with individual CT pattern, predominant pattern, fibrosis index or serial change in disease extent on CT or PFTs. Response on follow-up CT was associated with fibrosis index, predominant pattern and extent of consolidation on initial CT. CONCLUSION: In NSIP disease, progression on CT correlates with the predominant CT pattern, fibrosis index, and extent of consolidation but not with histopathological subtype. An inflammatory (ground-glass/consolidation) predominant pattern is associated with better outcome in terms of disease extent on HRCT.

Extramedullary paraspinal hematopoiesis in thalassemia: CT and MRI evaluation

International Nuclear Information System (INIS)

Tsitouridis, J.; Stamos, S.; Hassapopoulou, E.; Tsitouridis, K.; Nikolopoulos, P.

1999-01-01

We present a comparative CT and MRI study of the paraspinal extramedullary hematopoiesis in 32 thalassemic patients. The patients were classified into four groups according to the MRI and CT imaging findings. Active recent extramedullary paraspinal hematopoietic masses show soft tissue behavior in both CT and MRI. Older inactive masses reveal iron deposition or fatty replacement. Combined imaging findings of paraspinal extramedullary hematopoiesis revealed the phase of its evolution and the correct diagnosis

Extramedullary paraspinal hematopoiesis in thalassemia: CT and MRI evaluation

Energy Technology Data Exchange (ETDEWEB)

Tsitouridis, J.; Stamos, S.; Hassapopoulou, E.; Tsitouridis, K.; Nikolopoulos, P

1999-04-01

We present a comparative CT and MRI study of the paraspinal extramedullary hematopoiesis in 32 thalassemic patients. The patients were classified into four groups according to the MRI and CT imaging findings. Active recent extramedullary paraspinal hematopoietic masses show soft tissue behavior in both CT and MRI. Older inactive masses reveal iron deposition or fatty replacement. Combined imaging findings of paraspinal extramedullary hematopoiesis revealed the phase of its evolution and the correct diagnosis.

Localized Castleman's disease: CT and MRI findings

International Nuclear Information System (INIS)

Chen Zuhua; Yang Guangzhao

2008-01-01

Objective: To study the CT and MRI findings of localized Castleman's disease (LCD). Methods: The CT (n=7) and MRI (n=2) appearance of LCD (n=7) confirmed by pathology and operation were retrospectively analyzed. Results Hyaline-vascular type(n=6) and plasma cell type (n=1) were confirmed by pathology in LCD (n=7). They were located in middle mediastinum (n=2), hilum pulmonis (n=l), posterior mediastinum (n=3), retro-peritoneum (n=1). Hyaline-vascular type focuses in CT scanning were manifested as round shape soft tissue masses, with homogeneous density, integrity envelope, distinct margin, and chaperonage arborizing and spot calcification. Marked persistent enhancement was apparent on contrast CT. MRI findings of hyaline-vascular type (n=2) was slightly isointense or hyperintense on T 1 WI, homogeneous hyperintense on T 2 WI, similar enhancement with CT after contrast. Plasma cell type focus were unhomogeneous density with abnormity necrosis, media and unhomogeneous enhancement after contrast. Conclusion: Marked persistent enhancement of LCD would be helpful to diagnosis and differential diagnosis in Castleman's disease. (authors)

Late Adverse Events after Enhanced and Unenhanced MRI and CT

DEFF Research Database (Denmark)

Azzouz, Manal; Rømsing, Janne; Thomsen, Henrik S.

2014-01-01

Prospective evaluation of frequency of late and very late adverse events in patients undergoing enhanced or unenhanced magnetic resonance imaging (MRI) or computed tomography (CT). The imaging procedure was performed according to the protocols of the department. All patients were contacted three...... of LAEs was significantly higher in the enhanced MRI (38%) and CT (27%) groups than unenhanced MRI (20%) and CT (16%) groups. The frequency of nausea, dizziness, abdominal pain and diarrhoea was significantly higher in the enhanced MRI group than in the MRI control group, while taste sensation...

Visualisation of animal anatomy using MRI and CT

DEFF Research Database (Denmark)

Lauridsen, Henrik; Hansen, Kasper; Pedersen, Michael

imaging (MRI) and CT. Various species (tarantula, horseshoe crab, carp, haddock, lungfish, axolotl) were subjected to multi-slice MRI and CT protocols to produce 2D images of body slices, followed by volume rendering producing 3D digital models of animal anatomy with applications for visualising specific...

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.)

Cranial x-ray CT and MRI in congenital muscular dystrophy

International Nuclear Information System (INIS)

Horikawa, Hirosei; Konishi, Toshihiko; Konagaya, Masaaki; Mano, Yukio; Takayanagi, Tetsuya

1988-01-01

The involvements of central nervous system in those cases of congenital muscular dystrophy (CMD), especially in Fukuyama type CMD, have been observed both radiologically and pathologically. The recent development of MRI made it easier to detect fine structural changes in brain matter than the X-ray CT. Then, we tried to evaluate the central nervous system abnormalities of six cases of CMD by both X-ray CT and MRI. In one case, X-ray CT revealed diffuse hypodensity of cerebral white matter, and MRI showed high intensity on long spin-echo image and low intensity on inversion-recovery image. In another case, X-ray CT showed no abnormal findings, but long spin-echo image revealed two high intensity spots in cerebral white matter. In other four cases, brain atrophy was demonstrated by X-ray CT and/or MRI, one case of these patients had bilateral congenital arachnoid cysts in the middle cranial fossa and hypogenesis of temporal lobes. Although we could not demonstrate polymicrogyria and agyria in all cases by MRI, white matter changes and structural changes were revealed more clearly than X-ray CT. The combination of X-ray CT and MRI seems to make a noteworthy contribution to estimate the central nervous system abnormalities in CMD. (author)

CT and MRI diagnosis of renal oncocytoma

International Nuclear Information System (INIS)

Ren Shoujun; Wang Wenjia; Pan Shaohui; Gao Ji; Du Pengfei; Lu Fengxi; Wang Xiaohong

2007-01-01

Objective: To discuss the CT and MRI diagnostic value of renal oncocytoma and to improve the recognition of renal oncocytoma. Methods: Two cases of renal oncocytoma confirmed by pathology were retrospectively analyzed and related papers were reviewed. Results: Two cases were located in renal cortex, with smooth and sharp border, extruding outside of the kidneys. CT showed solid masses with lower density in center area as 'star'. On MRI T 1 WI and T 2 WI they also showed solid masses with low T 1 and high T 2 signal inensity in center area as 'star'. After contrast enhancement, the masses represented moderate enhancement and the central part did not show enhancement. Conclusion: Renal oncocytoma is a kind of rare nephroma provided with some characteristics in CT and MRI. (authors)

A comparison of the value of MRI and CT in patients with Nelson syndrome

International Nuclear Information System (INIS)

Kersjes, W.; Allmendinger, S.; Christ, F.; Stiebler, H.; Bockisch, A.; Klingmueller, D.

1992-01-01

The hypophyses of 13 patients with Nelson syndrome following bilateral adrenalectomy were examined by MRI and CT. Diffuse enlargement of the hypophysis was demonstrated in 8 patients by CT and in 9 by MRI. Compared with CT, MRI provides better demonstration of tumour development, such as abnormal convexity of the cranial margin of the hypophysis (MRI 4/13, CT 1/13), displacement of the infundibulum (MRI 4/13, CT 0/13) or optic chiasm (MRI 2/13, CT 0/13). MRI also provides diagnostically important differentiation between scar tissue and recurrence of tumour following hypophysectomy (MRI 1/3, CT 0/3) and more accurate demonstration of infiltration of the cavernous sinus (MRI 4/13, CT 2/13). CT is superior only in showing the floor of the sella. MRI is the method of choice for imaging in cases of Nelson syndrome. (orig.) [de

Vision 20/20: Simultaneous CT-MRI — Next chapter of multimodality imaging

International Nuclear Information System (INIS)

Wang, Ge; Xi, Yan; Gjesteby, Lars; Getzin, Matthew; Yang, Qingsong; Cong, Wenxiang; Kalra, Mannudeep; Murugan, Venkatesh; Vannier, Michael

2015-01-01

Multimodality imaging systems such as positron emission tomography-computed tomography (PET-CT) and MRI-PET are widely available, but a simultaneous CT-MRI instrument has not been developed. Synergies between independent modalities, e.g., CT, MRI, and PET/SPECT can be realized with image registration, but such postprocessing suffers from registration errors that can be avoided with synchronized data acquisition. The clinical potential of simultaneous CT-MRI is significant, especially in cardiovascular and oncologic applications where studies of the vulnerable plaque, response to cancer therapy, and kinetic and dynamic mechanisms of targeted agents are limited by current imaging technologies. The rationale, feasibility, and realization of simultaneous CT-MRI are described in this perspective paper. The enabling technologies include interior tomography, unique gantry designs, open magnet and RF sequences, and source and detector adaptation. Based on the experience with PET-CT, PET-MRI, and MRI-LINAC instrumentation where hardware innovation and performance optimization were instrumental to construct commercial systems, the authors provide top-level concepts for simultaneous CT-MRI to meet clinical requirements and new challenges. Simultaneous CT-MRI fills a major gap of modality coupling and represents a key step toward the so-called “omnitomography” defined as the integration of all relevant imaging modalities for systems biology and precision medicine

Vision 20/20: Simultaneous CT-MRI — Next chapter of multimodality imaging

Energy Technology Data Exchange (ETDEWEB)

Wang, Ge, E-mail: wangg6@rpi.edu; Xi, Yan; Gjesteby, Lars; Getzin, Matthew; Yang, Qingsong; Cong, Wenxiang [Biomedical Imaging Center/Cluster, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Kalra, Mannudeep; Murugan, Venkatesh [Department of Imaging, Massachusetts General Hospital, 55 Fruit Street, Boston, Massachusetts 02114 (United States); Vannier, Michael [Department of Radiology, University of Chicago, Chicago, Illinois 60637 (United States)

2015-10-15

Multimodality imaging systems such as positron emission tomography-computed tomography (PET-CT) and MRI-PET are widely available, but a simultaneous CT-MRI instrument has not been developed. Synergies between independent modalities, e.g., CT, MRI, and PET/SPECT can be realized with image registration, but such postprocessing suffers from registration errors that can be avoided with synchronized data acquisition. The clinical potential of simultaneous CT-MRI is significant, especially in cardiovascular and oncologic applications where studies of the vulnerable plaque, response to cancer therapy, and kinetic and dynamic mechanisms of targeted agents are limited by current imaging technologies. The rationale, feasibility, and realization of simultaneous CT-MRI are described in this perspective paper. The enabling technologies include interior tomography, unique gantry designs, open magnet and RF sequences, and source and detector adaptation. Based on the experience with PET-CT, PET-MRI, and MRI-LINAC instrumentation where hardware innovation and performance optimization were instrumental to construct commercial systems, the authors provide top-level concepts for simultaneous CT-MRI to meet clinical requirements and new challenges. Simultaneous CT-MRI fills a major gap of modality coupling and represents a key step toward the so-called “omnitomography” defined as the integration of all relevant imaging modalities for systems biology and precision medicine.

Serial MRI studies using gadolinium DTPA in active multiple sclerosis

International Nuclear Information System (INIS)

Miller, D.H.; Johnson, G.; Barnes, D.; Rudge, P.; McDonald, W.I.

1988-01-01

It has been suggested that blood brain barrier (BBB) impairment is a necessary early event in the pathogenesis of the multiple sclerosis (MS) lesions. To evaluate such an hypothesis in vivo would require: (1) serial imaging studies using a modality with high sensitivity for detecting plaques; (2) a contrast enhancing agent which demonstrates BBB impairment. A serial magnetic resonance imaging (MRI) study was undertaken of a group of MS patients using the contrast agent gadolinium-DTPA. As it has been suggested that T 1 and T 2 relaxation times are longer in acute than chronic MS lesions, these were also measured. 3 refs.; 1 figure

The comparative study of CT and MRI on femoral head necrosis

International Nuclear Information System (INIS)

Lin Yunliang; Liu Xianghua; Wu Shiqiang; Zeng Kangnian

2008-01-01

Objective: To compare the imaging features of CT and MRI in the femoral head necrosis as well as their pathological basis. Methods: 18 cases (30 hips) with femoral head necrosis proved by follow-up studies or pathology were analyzed, including 3 cases of pathological data. Results: The blurred high-density sclerotic line on CT in 28 hips were corresponded to 'line-like signs' on MRI, whereas, the other two hips without blurred high-density sclerosis line appeared 'line-like signs' on MRI. The normal area surrounded by the high-density line on CT in 26 hips were corresponded to fat-like signal area in 12 hips and mixed signal area in 14 hips on MRI. The other 4 hips with blurred bony trabeculum surrounded by the high-density line on CT showed mixed signal intensity on MRI. Conclusion: The high-density sclerotic line on CT corresponds to 'line-like sign' on MRI, which was considered as reactive interface between necrotic and viable region, was a specific signs to diagnose FHN. Compared with CT, MRI can accurately reflect pathological process during different repaired stages. (authors)

CT and MRI diagnosis of tubo-ovarian masses

International Nuclear Information System (INIS)

Xiong Minghui; Zhang Wanshi; Wang Dong

2000-01-01

Objective: To evaluate the diagnostic value of CT and MRI in tubo-ovarian masses. Methods: CT scan was performed in 67 patients with tubo-ovarian masses confirmed by pathology. 19 of them underwent MRI. Results: (1) 20 primary malignant ovarian tumors showed cystic,solid or cystic-solid masses; papillary projections on cystic wall; pelvic organs and pelvic wall invasion. Chocolate cysts with malignant degeneration exhibited small nodules on thickened cystic wall on CT and MRI. T 1 WI was better for revealing the lesions. (2) Of 11 cases of metastasis to tubo-ovary, 4 showed peritoneal linear enhancement. (3) There were 9 cystadenomas and 2 adenofibromas, one of the cystadenomas contained fat, two adenofibromas were similar to uterus in density on CT while showing lower signal intensity on MRI (both T 1 WI and T 2 WI). (4) Three cases of thecoma exhibited cystic or solid masses, solid thecomas revealed granular enhancement. (5) Teratomas were most specific, one of them was associated with thecoma. (6) Tubo-ovarian abscesses and tuberculosis depicted cystic or cystic-solid masses. (7) Two cases of tubal pregnancy showed inhomogeneous soft tissue masses, the lower density areas in the centers were clot and organized tissues confirmed by pathology. Conclusion: (1) CT and MRI had higher sensitivity but lower specificity for tubo-ovarian masses, the diagnosis should be combined with clinical history and patients' age. (2) Tumors of two different types may coexist and sometimes fat may be present in tumors other than teratoma

Mesenchymal chondrosarcoma of the orbit: CT and MRI findings

Energy Technology Data Exchange (ETDEWEB)

Yang, B.T., E-mail: cjr.yangbentao@vip.163.com [Department of Radiology, Beijing Tongren Hospital, Capital Medical University, Beijing (China); Wang, Y.Z.; Wang, X.Y.; Wang, Z.C. [Department of Radiology, Beijing Tongren Hospital, Capital Medical University, Beijing (China)

2012-04-15

Aim: To describe the computed tomography (CT) and magnetic resonance imaging (MRI) features of orbital mesenchymal chondrosarcomas (MCSs). Materials and methods: Six patients with histology-confirmed MCSs of the orbit were retrospectively reviewed. All six patients underwent CT and MRI. Imaging studies were evaluated for the following: (a) tumour location, (b) configuration, size, and margin, (c) CT attenuation and MRI signal intensity, and (d) secondary manifestations. Additionally, the time-intensity curve (TIC) of dynamic contrast-enhanced (DCE) MRI were analysed in five patients. Results: Two MCSs arose in the right orbit and four in the left orbit. Five MCSs were located in the retrobulbar intraconal space and one in the extraconal space. All the lesions displayed a lobulate configuration and had a well-defined margin. The mean maximum diameter was 25.8 mm (range 15-36 mm). On unenhanced CT, the lesions appeared isodense to grey matter in six patients, with calcifications in five. Two patients showed inhomogeneous, moderate enhancement on enhanced CT. Six MCSs appeared isointense on T1-weighted imaging and heterogeneously isointense on T2-weighted imaging. The lesions showed significantly heterogeneous contrast enhancement. Five patients had DCE MRI and the TICs showed a rapidly enhancing and rapid washout pattern (type III). The following features were also detected: compression of the extra-ocular muscle (six patients, 100%); displacement of the optic nerve (five patients, 83.3%); and encasing globe (three patients, 50%). Conclusions: A well-defined, lobulate orbital mass with calcification on CT and, marked heterogeneous enhancement and type III TIC on MRI are highly suspicious of orbital MCSs.

Comparison of Dynamic Contrast-Enhanced MRI and PET/CT in the Evaluation of Laryngeal Cancer After Inadequate CT Results

International Nuclear Information System (INIS)

Citil, Serdal; Dogan, Serap; Atilgan, Hasan Ikbal; Menzilcioglu, Mehmet Sait; Sahin, Tuna; Abdulrezzak, Ummuhan; Duymus, Mahmut; Ozturk, Mustafa

2015-01-01

To investigate the diagnostic value of dynamic magnetic resonance imaging (MRI) and positron emission tomography/computed tomography (PET/CT) for laryngeal cancers after inadequate CT results. The study comprised 45 patients investigated for primary laryngeal cancer or recurrence-residue in which CT was considered inadequate. A mass was found in 20 patients. Dynamic MRI and PET/CT were compared for diagnosis of mass, lymph node involvement, recurrence and residue. The dynamic curves formed in dynamic MRI were investigated for diagnostic contributions. The sensitivity and specificity of the dynamic MRI, for supraglottic, glottic and subglottic location, was 100%, 80%, and 92%; 100%, 85%, and 100%, respectively. In PET/CT the sensitivity and specificity were 100% for all of those localizations. For lymph node involvement, the sensitivity of dynamic MRI and PET/CT was 100%, the specificity was 100% and 93%, respectively. For recurrence-residue, the sensitivity and specificity of dynamic MRI were 86% and 67%, respectively, with 100% sensitivity and specificity in PET/CT. The sensitivity of type A curve for detection of malignancy was 40%, and specificity was 100%. When type A and B curves were included, the sensitivity was 100%. For patients investigated for laryngeal cancer in which CT is considered inadequate, dynamic MRI or PET/CT is useful

Comparison of Dynamic Contrast-Enhanced MRI and PET/CT in the Evaluation of Laryngeal Cancer After Inadequate CT Results.

Science.gov (United States)

Citil, Serdal; Dogan, Serap; Atilgan, Hasan Ikbal; Menzilcioglu, Mehmet Sait; Sahin, Tuna; Abdulrezzak, Ummuhan; Duymus, Mahmut; Ozturk, Mustafa

2015-01-01

To investigate the diagnostic value of dynamic magnetic resonance imaging (MRI) and positron emission tomography/computed tomography (PET/CT) for laryngeal cancers after inadequate CT results. The study comprised 45 patients investigated for primary laryngeal cancer or recurrence-residue in which CT was considered inadequate. A mass was found in 20 patients. Dynamic MRI and PET/CT were compared for diagnosis of mass, lymph node involvement, recurrence and residue. The dynamic curves formed in dynamic MRI were investigated for diagnostic contributions. The sensitivity and specificity of the dynamic MRI, for supraglottic, glottic and subglottic location, was 100%, 80%, and 92%; 100%, 85%, and 100%, respectively. In PET/CT the sensitivity and specificity were 100% for all of those localizations. For lymph node involvement, the sensitivity of dynamic MRI and PET/CT was 100%, the specificity was 100% and 93%, respectively. For recurrence-residue, the sensitivity and specificity of dynamic MRI were 86% and 67%, respectively, with 100% sensitivity and specificity in PET/CT. The sensitivity of type A curve for detection of malignancy was 40%, and specificity was 100%. When type A and B curves were included, the sensitivity was 100%. For patients investigated for laryngeal cancer in which CT is considered inadequate, dynamic MRI or PET/CT is useful.

CT, MRI and MRA of cerebrovascular malformations (report of 16 cases)

International Nuclear Information System (INIS)

Ding Qingguo; Hu Chunhong; Guo Liang; Ding Yi

2000-01-01

Objective: To evaluate the value of CT, MRI and MRA in cerebrovascular malformations. Methods: 16 cases of cerebrovascular malformations were confirmed by angiography and pathology, including 12 cases of arteriovenous malformations, 4 cases of cavernous angiomas. All of these cases were performed with CT, MRI non-contrast scan and 3D-TOF MRA. Results: CT appearances of AVM were mixed density with hypo-density, iso-density or hyper-density. Some had calcification or acute hemorrhage. MRI scan showed the dilated and tortuous nidus of AVMs on T 1 WI and T 2 WI. The appearances of hemorrhage were variable. Feeding arteries and draining veins were showed clearly on MRA. The typical sign of cavernous angiomas was mixed signals with hypointensity ring on MRI, while MRA could not provide much information. Conclusions: CT, MRI and MRA had different value in diagnosis of cerebrovascular malformations. CT combined with MRI and MRA could sharply improve the accuracy of diagnosis, and aid in the comprehensive evaluation of cerebrovascular malformations

Invisible fat on CT: making it visible by MRI.

Science.gov (United States)

Ünal, Emre; Karaosmanoğlu, Ali Devrim; Akata, Deniz; Özmen, Mustafa Nasuh; Karçaaltıncaba, Muşturay

2016-01-01

Presence of fat in a lesion significantly narrows the differential diagnosis. Small quantities of macroscopic fat and intracellular fat are invisible on computed tomography (CT) and ultrasonography. Magnetic resonance imaging (MRI) can reveal any fatty change in a lesion and can also differentiate macroscopic fat from intracellular and intravoxel fat. Hypodensity on CT may be a sign of invisible fat and MRI can help to diagnose even minute amounts of fat in liver, pancreas, adrenal, musculoskeletal, and omental pseudolesions and lesions. This article will review the superiority of MRI over CT in demonstrating fat in abdominal lesions.

Adrenal cavernous hemangioma: MRI, CT, and US appearance

International Nuclear Information System (INIS)

Marotti, M.; Sucic, Z.; Krolo, I.; Dimanovski, J.; Klaric, R.; Ferencic, Z.; Karapanda, N.; Babic, N.; Pavlekovic, K.

1997-01-01

Two cases of rare adrenal cavernous hemangiomas are reported, one imaged with conventional X-ray techniques, US, CT, and MRI, and the other with US and CT. The CT technique clearly demonstrated calcifications and the internal structure of the lesions in both cases and peripheral rim enhancement on the postcontrast scan in one patient. Although MRI demonstrated accurately the complex nature of the lesion, the inability to visualize the calcified areas do not allow to make a specific histologic diagnosis. (orig.). With 8 figs

Benign and malignant skull-involved lesions: discriminative value of conventional CT and MRI combined with diffusion-weighted MRI.

Science.gov (United States)

Tu, Zhanhai; Xiao, Zebin; Zheng, Yingyan; Huang, Hongjie; Yang, Libin; Cao, Dairong

2018-01-01

Background Little is known about the value of computed tomography (CT) and magnetic resonance imaging (MRI) combined with diffusion-weighted imaging (DWI) in distinguishing malignant from benign skull-involved lesions. Purpose To evaluate the discriminative value of DWI combined with conventional CT and MRI for differentiating between benign and malignant skull-involved lesions. Material and Methods CT and MRI findings of 58 patients with pathologically proven skull-involved lesions (43 benign and 15 malignant) were retrospectively reviewed. Conventional CT and MRI characteristics and apparent diffusion coefficient (ADC) value of the two groups were evaluated and compared. Multivariate logistic regression and receiver operating characteristic (ROC) curve analyses were performed to assess the differential performance of each parameter separately and together. Results The presence of cortical defects or break-through and ill-defined margins were associated with malignant skull-involved lesions (both P benign and malignant skull-involved lesions. Conclusion The combination of CT, MRI, and DWI can help to differentiate malignant from benign skull-involved lesions. CT + MRI + DWI offers optimal sensitivity, while DWI offers optimal specificity.

CT and MRI diagnosis of traumatic basal ganglia hemorrhage

International Nuclear Information System (INIS)

Wu Shike; Zhang Yalin; Xu Derong; Zou Gaowei; Chen Dan; He Sujun; Zhou Lichao

2009-01-01

Objective: To analyze CT and MRI features of traumatic basal ganglia hemorrhage and investigate the diagnostic value. Methods: 21 cases with traumatic basal ganglia hemorrhage diagnosed by clinic, CT and MRI in our hospital were collected in this study Plain CT scan were immediately performed in 21 cases after injury, plain MR scan were performed in 1 to 3 days. 12 cases of them underwent diffusion weighted imagine (DWI). The CT and MRI findings were retrospectively summarized. Results: 8 cases were found with simple traumatic basal ganglia hemorrhage. Complexity of basal ganglia hemorrhage occurred in 13 cases, 6 cases combined with subdural hemorrhage, 3 cases with epidural hematoma, 2 cases with subarachnoid hemorrhage, 6 cases with brain contusion and laceration in other locations, 4 cases with skull fracture. 26 lesions of basal ganglia hematoma were showed in 21 cases, 14 lesions of pallidum hemorrhage in 11 cases confirmed by MR could not be distinguished from calcification at the fast CT scan. 5 more lesions of brain contusion and laceration and 4 more lesions of brain white matter laceration were found by MR. Conclusion: CT in combination with MRI can diagnose traumatic basal ganglia hemorrhage and its complications early, comprehensively and accurately, which plays an important role in the clinical therapy selection and prognosis evaluation. (authors)

CT and MRI diagnosis of intracranial chondroma

International Nuclear Information System (INIS)

Liu Xuejun; Sui Qinglan

2006-01-01

Objective: To summarize and study the features of intracranial chondroma on CT and MRI imaging. Methods: CT and MRI findings of ten cases of intracranial chondroma proved by surgery and pathology from 1994. 1 to 2004.9 were retrospectively analyzed. Results: Among 10 cases, 4 cases were located at the skull base, 4 cases at convexity, 1 case at the region of falx cerebri, and 1 case within the brain parenchyma. CT scans showed obvious calcification and clear border of the tumors in 10 cases, mixed attenuation in 9 eases, and adjacent bone invasion in 5 cases. 4 cases of MRI scans showed hypointense signal on T 1 and T 2 -weighted images in calcified element of the tumor, intermediate to hypointense signal intensity on T 1 -weighted image, and hyperintense signal intensity on T 2 -weighted image in parenchyma of the tumor. 4 cases of CT scans showed slightly enhancement. Conclusion: Intracranial chondroma are often originated from synchondrosis of the skull base, convexity of brain and region of falx cerebri. Obvious calcification may be seen in most cases. Slightly enhancement and marked delayed contrast enhancement were characteristic. The accurate diagnosis still depends on pathology. (authors)

Indeterminate findings on oncologic PET/CT: What difference dose PET/MRI make?

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Fraum, Tyler J.; Fowler, Kathryn J.; McConathy, Jonathan; Dehdashti, Farokh [Mallinckrodt Institute of Radiology, Washington University School of Medicine, Saint Louis (United States)

2016-12-15

Positron emission tomography/computed tomography (PET/CT) with 2-deoxy-2-[{sup 18}F]fluoro-D-glucose (FDG) has become the standard of care for the initial staging and subsequent treatment response assessment of many different malignancies. Despite this success, PET/CT is often supplemented by MRI to improve assessment of local tumor invasion and to facilitate detection of lesions in organs with high background FDG uptake. Consequently, PET/MRI has the potential to expand the clinical value of PET examinations by increasing reader certainty and reducing the need for subsequent imaging. This study evaluates the ability of FDG-PET/MRI to clarify findings initially deemed indeterminate on clinical FDG-PET/CT studies. A total of 190 oncology patients underwent whole-body PET/CT, immediately followed by PET/MRI utilizing the same FDG administration. Each PET/CT was interpreted by our institution's nuclear medicine service as a standard-of-care clinical examination. Review of these PET/CT reports identified 31 patients (16 %) with indeterminate findings. Two readers evaluated all 31 PET/CT studies, followed by the corresponding PET/MRI studies. A consensus was reached for each case, and changes in interpretation directly resulting from PET/MRI review were recorded. Interpretations were then correlated with follow-up imaging, pathology results, and other diagnostic studies. In 18 of 31 cases with indeterminate findings on PET/CT, PET/MRI resulted in a more definitive interpretation by facilitating the differentiation of infection/inflammation from malignancy (15/18), the accurate localization of FDG-avid lesions (2/18), and the characterization of incidental non-FDG-avid solid organ lesions (1/18). Explanations for improved reader certainty with PET/MRI included the superior soft tissue contrast of MRI and the ability to assess cellular density with diffusion-weighted imaging. The majority (12/18) of such cases had an appropriate standard of reference; in all 12 cases

Indeterminate findings on oncologic PET/CT: What difference dose PET/MRI make?

International Nuclear Information System (INIS)

Fraum, Tyler J.; Fowler, Kathryn J.; McConathy, Jonathan; Dehdashti, Farokh

2016-01-01

Positron emission tomography/computed tomography (PET/CT) with 2-deoxy-2-["1"8F]fluoro-D-glucose (FDG) has become the standard of care for the initial staging and subsequent treatment response assessment of many different malignancies. Despite this success, PET/CT is often supplemented by MRI to improve assessment of local tumor invasion and to facilitate detection of lesions in organs with high background FDG uptake. Consequently, PET/MRI has the potential to expand the clinical value of PET examinations by increasing reader certainty and reducing the need for subsequent imaging. This study evaluates the ability of FDG-PET/MRI to clarify findings initially deemed indeterminate on clinical FDG-PET/CT studies. A total of 190 oncology patients underwent whole-body PET/CT, immediately followed by PET/MRI utilizing the same FDG administration. Each PET/CT was interpreted by our institution's nuclear medicine service as a standard-of-care clinical examination. Review of these PET/CT reports identified 31 patients (16 %) with indeterminate findings. Two readers evaluated all 31 PET/CT studies, followed by the corresponding PET/MRI studies. A consensus was reached for each case, and changes in interpretation directly resulting from PET/MRI review were recorded. Interpretations were then correlated with follow-up imaging, pathology results, and other diagnostic studies. In 18 of 31 cases with indeterminate findings on PET/CT, PET/MRI resulted in a more definitive interpretation by facilitating the differentiation of infection/inflammation from malignancy (15/18), the accurate localization of FDG-avid lesions (2/18), and the characterization of incidental non-FDG-avid solid organ lesions (1/18). Explanations for improved reader certainty with PET/MRI included the superior soft tissue contrast of MRI and the ability to assess cellular density with diffusion-weighted imaging. The majority (12/18) of such cases had an appropriate standard of reference; in all 12 cases, the

Interobserver Delineation variation using CT versus combined CT + MRI in intensity- modulated radiotherapy for prostate cancer

International Nuclear Information System (INIS)

Villeirs, G.M.; Verstraete, K.L.; Vaerenbergh, K. van; Vakaet, L.; Bral, S.; Claus, F.; Neve, W.J. de; Meerleer, G.O. de

2005-01-01

Purpose: to quantify interobserver variation of prostate and seminal vesicle delineations using CT only versus CT + MRI in consensus reading with a radiologist. Material and methods: the prostate and seminal vesicles of 13 patients treated with intensity-modulated radiotherapy for prostatic adenocarcinoma were retrospectively delineated by three radiation oncologists on CT only and on CT + MRI in consensus reading with a radiologist. The volumes and margin positions were calculated and intermodality and interobserver variations were assessed for the clinical target volume (CTV), seminal vesicles, prostate and three prostatic subdivisions (apical, middle and basal third). Results: using CT + MRI as compared to CT alone, the mean CTV, prostate and seminal vesicle volumes significantly decreased by 6.54%, 5.21% and 10.47%, respectively. More importantly, their standard deviations significantly decreased by 63.06%, 62.65% and 44.83%, respectively. The highest level of variation was found at the prostatic apex, followed by the prostatic base and seminal vesicles. Conclusion: addition of MRI to CT in consensus reading with a radiologist results in a moderate decrease of the CTV, but an important decrease of the interobserver delineation variation, especially at the prostatic apex. (orig.)

Automated detection of multiple sclerosis lesions in serial brain MRI

International Nuclear Information System (INIS)

Llado, Xavier; Ganiler, Onur; Oliver, Arnau; Marti, Robert; Freixenet, Jordi; Valls, Laia; Vilanova, Joan C.; Ramio-Torrenta, Lluis; Rovira, Alex

2012-01-01

Multiple sclerosis (MS) is a serious disease typically occurring in the brain whose diagnosis and efficacy of treatment monitoring are vital. Magnetic resonance imaging (MRI) is frequently used in serial brain imaging due to the rich and detailed information provided. Time-series analysis of images is widely used for MS diagnosis and patient follow-up. However, conventional manual methods are time-consuming, subjective, and error-prone. Thus, the development of automated techniques for the detection and quantification of MS lesions is a major challenge. This paper presents an up-to-date review of the approaches which deal with the time-series analysis of brain MRI for detecting active MS lesions and quantifying lesion load change. We provide a comprehensive reference source for researchers in which several approaches to change detection and quantification of MS lesions are investigated and classified. We also analyze the results provided by the approaches, discuss open problems, and point out possible future trends. Lesion detection approaches are required for the detection of static lesions and for diagnostic purposes, while either quantification of detected lesions or change detection algorithms are needed to follow up MS patients. However, there is not yet a single approach that can emerge as a standard for the clinical practice, automatically providing an accurate MS lesion evolution quantification. Future trends will focus on combining the lesion detection in single studies with the analysis of the change detection in serial MRI. (orig.)

Automated detection of multiple sclerosis lesions in serial brain MRI

Energy Technology Data Exchange (ETDEWEB)

Llado, Xavier; Ganiler, Onur; Oliver, Arnau; Marti, Robert; Freixenet, Jordi [University of Girona, Computer Vision and Robotics Group, Girona (Spain); Valls, Laia [Dr. Josep Trueta University Hospital, Department of Radiology, Girona (Spain); Vilanova, Joan C. [Girona Magnetic Resonance Center, Girona (Spain); Ramio-Torrenta, Lluis [Dr. Josep Trueta University Hospital, Institut d' Investigacio Biomedica de Girona, Multiple Sclerosis and Neuroimmunology Unit, Girona (Spain); Rovira, Alex [Vall d' Hebron University Hospital, Magnetic Resonance Unit, Department of Radiology, Barcelona (Spain)

2012-08-15

Multiple sclerosis (MS) is a serious disease typically occurring in the brain whose diagnosis and efficacy of treatment monitoring are vital. Magnetic resonance imaging (MRI) is frequently used in serial brain imaging due to the rich and detailed information provided. Time-series analysis of images is widely used for MS diagnosis and patient follow-up. However, conventional manual methods are time-consuming, subjective, and error-prone. Thus, the development of automated techniques for the detection and quantification of MS lesions is a major challenge. This paper presents an up-to-date review of the approaches which deal with the time-series analysis of brain MRI for detecting active MS lesions and quantifying lesion load change. We provide a comprehensive reference source for researchers in which several approaches to change detection and quantification of MS lesions are investigated and classified. We also analyze the results provided by the approaches, discuss open problems, and point out possible future trends. Lesion detection approaches are required for the detection of static lesions and for diagnostic purposes, while either quantification of detected lesions or change detection algorithms are needed to follow up MS patients. However, there is not yet a single approach that can emerge as a standard for the clinical practice, automatically providing an accurate MS lesion evolution quantification. Future trends will focus on combining the lesion detection in single studies with the analysis of the change detection in serial MRI. (orig.)

Zero-Echo-Time and Dixon Deep Pseudo-CT (ZeDD CT): Direct Generation of Pseudo-CT Images for Pelvic PET/MRI Attenuation Correction Using Deep Convolutional Neural Networks with Multiparametric MRI.

Science.gov (United States)

Leynes, Andrew P; Yang, Jaewon; Wiesinger, Florian; Kaushik, Sandeep S; Shanbhag, Dattesh D; Seo, Youngho; Hope, Thomas A; Larson, Peder E Z

2018-05-01

Accurate quantification of uptake on PET images depends on accurate attenuation correction in reconstruction. Current MR-based attenuation correction methods for body PET use a fat and water map derived from a 2-echo Dixon MRI sequence in which bone is neglected. Ultrashort-echo-time or zero-echo-time (ZTE) pulse sequences can capture bone information. We propose the use of patient-specific multiparametric MRI consisting of Dixon MRI and proton-density-weighted ZTE MRI to directly synthesize pseudo-CT images with a deep learning model: we call this method ZTE and Dixon deep pseudo-CT (ZeDD CT). Methods: Twenty-six patients were scanned using an integrated 3-T time-of-flight PET/MRI system. Helical CT images of the patients were acquired separately. A deep convolutional neural network was trained to transform ZTE and Dixon MR images into pseudo-CT images. Ten patients were used for model training, and 16 patients were used for evaluation. Bone and soft-tissue lesions were identified, and the SUV max was measured. The root-mean-squared error (RMSE) was used to compare the MR-based attenuation correction with the ground-truth CT attenuation correction. Results: In total, 30 bone lesions and 60 soft-tissue lesions were evaluated. The RMSE in PET quantification was reduced by a factor of 4 for bone lesions (10.24% for Dixon PET and 2.68% for ZeDD PET) and by a factor of 1.5 for soft-tissue lesions (6.24% for Dixon PET and 4.07% for ZeDD PET). Conclusion: ZeDD CT produces natural-looking and quantitatively accurate pseudo-CT images and reduces error in pelvic PET/MRI attenuation correction compared with standard methods. © 2018 by the Society of Nuclear Medicine and Molecular Imaging.

Proton MRI in the evaluation of pulmonary sarcoidosis: Comparison to chest CT

International Nuclear Information System (INIS)

Chung, Jonathan H.; Little, Brent P.; Forssen, Anna V.; Yong, Jin; Nambu, Atsushi; Kazlouski, Demitry; Puderbach, Michael; Biederer, Juergen; Lynch, David A.

2013-01-01

Purpose: The purpose of this study was to determine the feasibility of proton MRI of the lung in sarcoidosis patients and the agreement between the imaging appearance of pulmonary sarcoidosis on MRI and CT. Materials and methods: Chest CT scans and dedicated pulmonary MRI scans (including HASTE, VIBE, and TrueFISP sequences) were performed within 90 days of each other in 29 patients. The scans were scored for gross parenchymal opacification, reticulation, nodules, and masses using a 3-point lobar scale. Total and subset scores for corresponding MRI and CT scans were compared using the Spearman correlation test, Bland–Altman plots, and Cohen's quadratic-weighted kappa analysis. MRI scores were compared to CT by lobe and disease category, using percentage agreement, Spearman rank correlation, and Cohen's quadratic-weighted kappa. Results: The mean (±s.d.) time between MRI and CT scans was 33 ± 32 days. There was substantial correlation and agreement between total disease scoring on MRI and CT with a Spearman correlation coefficient of 0.774 (p < 0.0001) and a Cohen's weighted kappa score of 0.646. Correlation and agreement were highest for gross parenchymal opacification (0.695, 0.528) and reticulation (0.609, 0.445), and lowest in the setting of nodules (0.501, 0.305). Agreement testing was not performed for mass scores due to low prevalence. Upper lobe scoring on MRI and CT demonstrated greater agreement compared to the lower lobes (average difference in Cohen's weighted kappa score of 0.112). Conclusion: There is substantial correlation and agreement between MRI and CT in the scoring of pulmonary sarcoidosis, though MRI evaluation in the upper lobes may be more accurate than in the lower lobes

Preoperative staging of rectal cancer by magnetic resonance imaging (MRI) and computed tomography (CT)

International Nuclear Information System (INIS)

Itabashi, Michiaki; Kameoka, Shingo; Nakajima, Kiyotaka; Izumi, Kiminari; Miyazaki, Kaname; Hamano, Kyoichi; Kouno, Atsushi

1991-01-01

To clarify the usefulness and limitations of CT and MRI in preoperative assessment of the wall invasion of rectal cancer, we compared the results of CT and MRI with the histopathological findings, classifying tumors by the region and site in 34 patients with rectal cancer. Subjects were patients preoperatively examined by MRI and CT. Overall, the percent of cases with the extent of invasion accurately assessed by MRI was 88.2%, and that by CT was 64.7%. In all instances of wrong assessment, the extent of invasion was overestimated. The accurate assessment rate was significantly higher for MRI than for CT. After classification by the region, the accurate assessment rate at Rs was low as 50% for both MRI and CT because slices were not perpendicular to the tumor. The accurate assessment rate was 100% for MRI and 82% for CT at Ra, and respectively 94% and 59% at Rb. The majority of tumors at Ra or Rb centering on the lateral wall of the rectum were accurately assessed either by MRI or CT. With tumors at Ra or Rb (particularly Rb) centering on the anterior or posterior wall, CT frequently failed to identify the extent of invasion accurately, so that MRI seemed more suitable for these tumors. (author)

Assessment of CF lung disease using motion corrected PROPELLER MRI: a comparison with CT

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Ciet, Pierluigi [General Hospital Ca' Foncello, Radiology Department, Treviso (Italy); Sophia Children' s Hospital, Pediatric Pulmonology Erasmus MC, Rotterdam (Netherlands); Erasmus MC, Radiology, Rotterdam (Netherlands); Serra, Goffredo; Catalano, Carlo [University of Rome ' ' Sapienza' ' , Radiology, Rome (Italy); Bertolo, Silvia; Morana, Giovanni [General Hospital Ca' Foncello, Radiology Department, Treviso (Italy); Spronk, Sandra [Erasmus MC, Radiology, Rotterdam (Netherlands); Erasmus MC, Epidemiology, Rotterdam (Netherlands); Ros, Mirco [Ca' Foncello Hospital, Pediatrics, Treviso (Italy); Fraioli, Francesco [University College London (UCL), Institute of Nuclear Medicine, London (United Kingdom); Quattrucci, Serena [University of Rome Sapienza, Pediatrics, Rome (Italy); Assael, M.B. [Azienda Ospedaliera di Verona, Verona CF Center, Verona (Italy); Pomerri, Fabio [University of Padova, Department of Medicine-DIMED, Padova (Italy); Tiddens, Harm A.W.M. [Sophia Children' s Hospital, Pediatric Pulmonology Erasmus MC, Rotterdam (Netherlands); Erasmus MC, Radiology, Rotterdam (Netherlands)

2016-03-15

To date, PROPELLER MRI, a breathing-motion-insensitive technique, has not been assessed for cystic fibrosis (CF) lung disease. We compared this technique to CT for assessing CF lung disease in children and adults. Thirty-eight stable CF patients (median 21 years, range 6-51 years, 22 female) underwent MRI and CT on the same day. Study protocol included respiratory-triggered PROPELLER MRI and volumetric CT end-inspiratory and -expiratory acquisitions. Two observers scored the images using the CF-MRI and CF-CT systems. Scores were compared with intra-class correlation coefficient (ICC) and Bland-Altman plots. The sensitivity and specificity of MRI versus CT were calculated. MRI sensitivity for detecting severe CF bronchiectasis was 0.33 (CI 0.09-0.57), while specificity was 100 % (CI 0.88-1). ICCs for bronchiectasis and trapped air were as follows: MRI-bronchiectasis (0.79); CT-bronchiectasis (0.85); MRI-trapped air (0.51); CT-trapped air (0.87). Bland-Altman plots showed an MRI tendency to overestimate the severity of bronchiectasis in mild CF disease and underestimate bronchiectasis in severe disease. Motion correction in PROPELLER MRI does not improve assessment of CF lung disease compared to CT. However, the good inter- and intra-observer agreement and the high specificity suggest that MRI might play a role in the short-term follow-up of CF lung disease (i.e. pulmonary exacerbations). (orig.)

Assessment of CF lung disease using motion corrected PROPELLER MRI: a comparison with CT

International Nuclear Information System (INIS)

Ciet, Pierluigi; Serra, Goffredo; Catalano, Carlo; Bertolo, Silvia; Morana, Giovanni; Spronk, Sandra; Ros, Mirco; Fraioli, Francesco; Quattrucci, Serena; Assael, M.B.; Pomerri, Fabio; Tiddens, Harm A.W.M.

2016-01-01

To date, PROPELLER MRI, a breathing-motion-insensitive technique, has not been assessed for cystic fibrosis (CF) lung disease. We compared this technique to CT for assessing CF lung disease in children and adults. Thirty-eight stable CF patients (median 21 years, range 6-51 years, 22 female) underwent MRI and CT on the same day. Study protocol included respiratory-triggered PROPELLER MRI and volumetric CT end-inspiratory and -expiratory acquisitions. Two observers scored the images using the CF-MRI and CF-CT systems. Scores were compared with intra-class correlation coefficient (ICC) and Bland-Altman plots. The sensitivity and specificity of MRI versus CT were calculated. MRI sensitivity for detecting severe CF bronchiectasis was 0.33 (CI 0.09-0.57), while specificity was 100 % (CI 0.88-1). ICCs for bronchiectasis and trapped air were as follows: MRI-bronchiectasis (0.79); CT-bronchiectasis (0.85); MRI-trapped air (0.51); CT-trapped air (0.87). Bland-Altman plots showed an MRI tendency to overestimate the severity of bronchiectasis in mild CF disease and underestimate bronchiectasis in severe disease. Motion correction in PROPELLER MRI does not improve assessment of CF lung disease compared to CT. However, the good inter- and intra-observer agreement and the high specificity suggest that MRI might play a role in the short-term follow-up of CF lung disease (i.e. pulmonary exacerbations). (orig.)

Imaging of abdominal tumours: CT or MRI?

International Nuclear Information System (INIS)

Olsen, Oeystein E.

2009-01-01

The scope of this review is to discuss a theoretical approach to imaging policy, particularly in the perspective of radiation risk reduction. Decisions are ideally driven by empirical evidence about efficacy and risk, e.g., in classical hierarchical efficacy model. As a result of the paucity of empirical evidence (inevitable because of rapid technological development), a pragmatic model is needed. This should avoid overemphasis of factors that currently seem to hamper change, namely personal preference, local expertise, infrastructure, availability. Extrapolation of current general knowledge about CT and MRI demonstrates how a pragmatic approach can be applied in the real world with intermediate goals such as (1) channeling patients from CT to MRI, and (2) reducing CT-delivered radiation. Increased utilisation of MRI in body imaging requires optimisation of scan protocols and equipment, and, being a very operator-dependent modality, the active involvement of the radiologist. In CT dose reduction the main challenge is to benchmark the minimum radiation-dose requirement, and therefore the minimum required image quality that is diagnostically acceptable. As this will ultimately depend on pre-test likelihoods in institutional populations, it is difficult to issue general guidance, and local assessment remains a cornerstone in this effort. (orig.)

Edge-oriented dual-dictionary guided enrichment (EDGE) for MRI-CT image reconstruction.

Science.gov (United States)

Li, Liang; Wang, Bigong; Wang, Ge

2016-01-01

In this paper, we formulate the joint/simultaneous X-ray CT and MRI image reconstruction. In particular, a novel algorithm is proposed for MRI image reconstruction from highly under-sampled MRI data and CT images. It consists of two steps. First, a training dataset is generated from a series of well-registered MRI and CT images on the same patients. Then, an initial MRI image of a patient can be reconstructed via edge-oriented dual-dictionary guided enrichment (EDGE) based on the training dataset and a CT image of the patient. Second, an MRI image is reconstructed using the dictionary learning (DL) algorithm from highly under-sampled k-space data and the initial MRI image. Our algorithm can establish a one-to-one correspondence between the two imaging modalities, and obtain a good initial MRI estimation. Both noise-free and noisy simulation studies were performed to evaluate and validate the proposed algorithm. The results with different under-sampling factors show that the proposed algorithm performed significantly better than those reconstructed using the DL algorithm from MRI data alone.

CT and MRI matching for radiotherapy planning in head and neck cancer

Energy Technology Data Exchange (ETDEWEB)

Rasch, C; Keus, R; Touw, A; Lebesque, J; Van Herk, M [Nederlands Kanker Inst. ` Antoni van Leeuwenhoekhuis` , Amsterdam (Netherlands)

1995-12-01

The objective of this study was to evaluate the impact of matched CT and MRI information on target delineation in radiotherapy planning for head and neck tumors. MRI images of eight patients with head and neck cancer in supine position, not necessarily obtained in radiotherapy treatment position were matched to the CT scans made in radiotherapy position using automatic three-dimensional chamfer-matching of bony structures. Four independent observers delineated the Gross Tumor Volume (GTV) in CT scans and axial and sagittal MR scans. The GTV`s were compared, overlapping volumes and non-overlapping volumes between the different datasets and observers were determined. In all patients a good match of CT and MRI information was accomplished in the head region. The combined information provided a better visualisation of the GTV, oedema and normal tissues compared with CT or MRI alone. Determination of overlapping and non-overlapping volumes proved to be a valuable tool to measure uncertainties in the determination of the GTV. CT-MRI matching in patients with head and neck tumors is feasible and makes a more accurate irradiation with higher tumor doses and less normal tissue complications possible. Remaining uncertainties in the determination of the GTV can be quantified using the combined information of MRI and CT.

SU-F-BRF-10: Deformable MRI to CT Validation Employing Same Day Planning MRI for Surrogate Analysis

Energy Technology Data Exchange (ETDEWEB)

Padgett, K; Stoyanova, R; Johnson, P; Dogan, N; Pollack, A [University of Miami School of Medicine, Miami, FL (United States); Piper, J; Javorek, A [MIM Software, Inc., Beachwood, OH (United States)

2014-06-15

Purpose: To compare rigid and deformable registrations of the prostate in the multi-modality setting (diagnostic-MRI to planning-CT) by utilizing a planning-MRI as a surrogate. The surrogate allows for the direct quantitative analysis which can be difficult in the multi-modality domain where intensity mapping differs. Methods: For ten subjects, T2 fast-spin-echo images were acquired at two different time points, the first several weeks prior to planning (diagnostic-MRI) and the second on the same day in which the planning CT was collected (planning-MRI). Significant effort in patient positioning and bowel/bladder preparation was undertaken to minimize distortion of the prostate in all datasets. The diagnostic-MRI was deformed to the planning-CT utilizing a commercially available deformable registration algorithm synthesized from local registrations. The deformed MRI was then rigidly aligned to the planning MRI which was used as the surrogate for the planning-CT. Agreement between the two MRI datasets was scored using intensity based metrics including Pearson correlation and normalized mutual information, NMI. A local analysis was performed by looking only within the prostate, proximal seminal vesicles, penile bulb and combined areas. A similar method was used to assess a rigid registration between the diagnostic-MRI and planning-CT. Results: Utilizing the NMI, the deformable registrations were superior to the rigid registrations in 9 of 10 cases demonstrating a 15.94% improvement (p-value < 0.001) within the combined area. The Pearson correlation showed similar results with the deformable registration superior in the same number of cases and demonstrating a 6.97% improvement (p-value <0.011). Conclusion: Validating deformable multi-modality registrations using spatial intensity based metrics is difficult due to the inherent differences in intensity mapping. This population provides an ideal testing ground for MRI to CT deformable registrations by obviating the need

MRI of atlantoaxial subluxation; Correlating with plain X-ray films and CT findings

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Saikawa, Yuko; Nishi, Naoko; Saitoh, Yoko; Akimura, Rumiko; Sasaki, Taisuke; Yodono, Hiraku; Takekawa, Shoichi; Harata, Seikou; Sannohe, Akio (Hirosaki Univ., Aomori (Japan). School of Medicine)

1991-04-01

Twenty-three patients with atlantoaxial subluxation (14 with rheumatoid arthritis, one each with rheumatoid arthritis and Arnold-Chiari malformation, os odontoideum, Klippel-Feil syndrome, trauma, and 5 with unknown causes) were evaluated with MRI. We used 0.5 T MRI unit (RESONA; Yokogawa Medical Systems, Japan) and 1.5 T MRI unit (SMT 150; Shimazu, Japan) with head or flexible coils. We compared the usefulness of MRI with those of plain X-ray films and CT regarding several points. MRI provided better image of the soft tissue mass around the odontoid process, compression of cord or subarachnoid space than plain X-ray films and CT. Atlanto-odontoid distance on MRI is nearer to that on plain X-ray films than CT. MRI is useful in analyzing the anatomic details such as transverse ligament, alar ligament, tectorial membrane and thickened synovium. Both MRI and CT provided detailed bony changes. High correlation was observed between MRI grading of cord compression and the degree of myelopathy. (author).

Leiomyoma of the sinonasal cavity: CT and MRI findings

International Nuclear Information System (INIS)

Yang, B.T.; Wang, Z.C.; Xian, J.F.; Hao, D.P.; Chen, Q.H.

2009-01-01

Aim: To determine the computed tomography (CT) and magnetic resonance imaging (MRI) features of leiomyoma of the sinonasal cavity. Materials and methods: Six patients with histology-proven leiomyomas in the sinonasal cavity were retrospectively reviewed. All six patients underwent CT and three patients also underwent MRI. The following imaging features were reviewed: size, margin, CT attenuation, MRI signal intensity, and lesion extent. In addition, the time-intensity curve (TIC) of dynamic contrast-enhanced (DCE) MRI and diffusion-weighted imaging (DWI) were analysed in two patients. Results: All leiomyomas had well-defined margins. The mean size was 36 mm (range 20-51 mm). On unenhanced CT, the lesions appeared isodense to cerebral grey matter in four (67%) and slightly hypodense in two (33%) patients. Leiomyomas appeared isointense On T1-weighted imaging (WI) and slightly hyperintense on T2WI in three patients. The lesions showed moderate contrast enhancement. Two patients underwent DCE MRI, and the TIC showed a rapidly enhancing and slow washout pattern. The mean apparent diffusion coefficient (ADC) value were 1.66 x 10 -3 mm 2 /s and 1.78 x 10 -3 mm 2 /s for the two lesions, respectively. Conclusions: Well-defined, homogeneous, expansile masses without bony erosion are typical features of leiomyoma. Althrough rare, this entity should be included in the differential diagnosis of benign tumours in this region.

Leiomyoma of the sinonasal cavity: CT and MRI findings

Energy Technology Data Exchange (ETDEWEB)

Yang, B.T., E-mail: cjr.yangbentao@vip.163.co [Department of Radiology, Beijing Tongren Hospital, Capital Medical University, Beijing (China); Wang, Z.C.; Xian, J.F.; Hao, D.P.; Chen, Q.H. [Department of Radiology, Beijing Tongren Hospital, Capital Medical University, Beijing (China)

2009-12-15

Aim: To determine the computed tomography (CT) and magnetic resonance imaging (MRI) features of leiomyoma of the sinonasal cavity. Materials and methods: Six patients with histology-proven leiomyomas in the sinonasal cavity were retrospectively reviewed. All six patients underwent CT and three patients also underwent MRI. The following imaging features were reviewed: size, margin, CT attenuation, MRI signal intensity, and lesion extent. In addition, the time-intensity curve (TIC) of dynamic contrast-enhanced (DCE) MRI and diffusion-weighted imaging (DWI) were analysed in two patients. Results: All leiomyomas had well-defined margins. The mean size was 36 mm (range 20-51 mm). On unenhanced CT, the lesions appeared isodense to cerebral grey matter in four (67%) and slightly hypodense in two (33%) patients. Leiomyomas appeared isointense On T1-weighted imaging (WI) and slightly hyperintense on T2WI in three patients. The lesions showed moderate contrast enhancement. Two patients underwent DCE MRI, and the TIC showed a rapidly enhancing and slow washout pattern. The mean apparent diffusion coefficient (ADC) value were 1.66 x 10{sup -3} mm{sup 2}/s and 1.78 x 10{sup -3} mm{sup 2}/s for the two lesions, respectively. Conclusions: Well-defined, homogeneous, expansile masses without bony erosion are typical features of leiomyoma. Althrough rare, this entity should be included in the differential diagnosis of benign tumours in this region.

The role of MRI and CT of the brain in first episodes of psychosis

International Nuclear Information System (INIS)

Khandanpour, N.; Hoggard, N.; Connolly, D.J.A.

2013-01-01

Aim: To investigate whether imaging is associated with early detection of the organic causes of the first episode of psychosis (FEP). Materials and methods: Individuals with FEP but no neurological signs referred to a tertiary centre for cerebral magnetic resonance imaging (MRI) or computed tomography (CT) were reviewed retrospectively. Two groups were evaluated with either CT or MRI; the two groups were independent and no individual underwent both CT and MRI. Results: One hundred and twelve consecutive cerebral MRI and 204 consecutive CT examinations were identified. Three (2.7%) individuals had brain lesions [brain tumour and human immunodeficiency virus (HIV) encephalopathy] potentially accountable for the psychosis at MRI. Seventy patients (62.5%) had incidental brain lesions, such as cerebral atrophy, small vessel ischaemic changes, unruptured Circle of Willis aneurysm, cavernoma, and arachnoid cysts at MRI. Three patients (1.5%) had focal brain lesions (primary or secondary tumours) potentially accountable for the psychosis at CT. One hundred and thirty-three patients (65.2%) had incidental brain lesions unrelated to the psychosis on CT scan. There was no significant difference between MRI and CT imaging in detecting organic disease potentially responsible for FEP (p < 0.001). Conclusion: Routine MRI or CT imaging of the brain is unlikely to reveal disease leading to a significant change in management. MRI was comparable with CT in terms of diagnosis of both pathological and incidental cerebral lesions. Therefore, routine brain structural imaging of FEP in patients without focal neurology may not be routinely required and if imaging is requested then CT may function equally as well as MRI as the first-line investigation

Rare manifestation of echinococcus cysticus presented in CT and MRI

International Nuclear Information System (INIS)

Wrazidlo, W.; Rieber, A.; Schneider, S.; Brambs, H.J.; Friedel, P.; Heidelberg Univ.

1989-01-01

A case of primary spinal echinococcus with bone destruction is presented and the findings in CT and MR imaging are discussed. Although CT and MRI are complementary studies for the diagnosis of the spinal echinococcosis, MRI is the study of choice for prolonged follow-up of complicated cases. (orig.) [de

Volumetric Assessment of Swallowing Muscles: A Comparison of CT and MRI Segmentation.

Science.gov (United States)

Sporns, Kim Barbara; Hanning, Uta; Schmidt, Rene; Muhle, Paul; Wirth, Rainer; Zimmer, Sebastian; Dziewas, Rainer; Suntrup-Krueger, Sonja; Sporns, Peter Bernhard; Heindel, Walter; Schwindt, Wolfram

2018-05-01

 Recent retrospective studies have proposed a high correlation between atrophy of swallowing muscles, age, severity of dysphagia and aspiration status based on computed tomography (CT). However, ionizing radiation poses an ethical barrier to research in prospective non-patient populations. Hence, there is a need to prove the efficacy of techniques that rely on noninvasive methods and produce high-resolution soft tissue images such as magnetic resonance imaging (MRI). The objective of this study was therefore to compare the segmentation results of swallowing muscles using CT and MRI.  Retrospective study of 21 patients (median age: 46.6; gender: 11 female) who underwent CT and MRI of the head and neck region within a time frame of less than 50 days because of suspected head and neck cancer using contrast agent. CT and MR images were segmented by two blinded readers using Medical Imaging Toolkit (MITK) and both modalities were tested (with the equivalence test) regarding the segmented muscle volumes. Adjustment for multiple testing was performed using the Bonferroni test and the potential time effect of the muscle volumes and the time interval between the modalities was assessed by a spearman correlation. The study was approved by the local ethics committee.  The median volumes for each muscle belly of the digastric muscle derived from CT were 3051 mm 3 (left) and 2969 mm 3 (right), and from MRI they were 3218 mm 3 (left) and 3027 mm 3 (right). The median volume of the geniohyoid muscle was 6580 mm 3 on CT and 6648 mm 3 on MRI. The interrater reliability was high for all segmented muscles. The mean time interval between the CT and MRI examinations was 34 days (IQR 25; 41). The muscle differences of each muscle between the two modalities did not reveal significant correlation to the time interval between the examinations (digastric left r = 0.003 and digastric right r = -0.008; geniohyoid muscle r = 0.075).  CT-based segmentation and

Adrenal pseudomasses due to varices: angiographic-CT-MRI-pathologic correlations

International Nuclear Information System (INIS)

Brady, T.M.; Gross, B.H.; Glazer, G.M.; Williams, D.M.

1985-01-01

Periadrenal and adrenal portosystemic collaterals are a recently reported cause of adrenal pseudotumor on computed tomography (CT). Nine patients with this left adrenal pseudotumor illustrate its typical position and appearance on CT, angiography, CT-angiography, and magnetic resonance imaging (MRI). The anatomic basis for variceal adrenal pseudotumors is the left inferior phrenic vein, which passes immediately anterior to the left adrenal gland and which serves as a collateral pathway from splenic to left renal vein in portal hypertension. Thus, unlike previously described adrenal pseudotumors, these venous collaterals are not anatomically distinguishable from the adrenal gland on CT. Bolus dynamic CT is usually diagnostic, but in equivocal cases, MRI may prove useful

Adrenal pseudomasses due to varices: angiographic-CT-MRI-pathologic correlations

Energy Technology Data Exchange (ETDEWEB)

Brady, T.M.; Gross, B.H.; Glazer, G.M. Williams, D.M.

1985-08-01

Periadrenal and adrenal portosystemic collaterals are a recently reported cause of adrenal pseudotumor on computed tomography (CT). Nine patients with this left adrenal pseudotumor illustrate its typical position and appearance on CT, angiography, CT-angiography, and magnetic resonance imaging (MRI). The anatomic basis for variceal adrenal pseudotumors is the left inferior phrenic vein, which passes immediately anterior to the left adrenal gland and which serves as a collateral pathway from splenic to left renal vein in portal hypertension. Thus, unlike previously described adrenal pseudotumors, these venous collaterals are not anatomically distinguishable from the adrenal gland on CT. Bolus dynamic CT is usually diagnostic, but in equivocal cases, MRI may prove useful.

Age determination of subdural hematomas with CT and MRI: A systematic review

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Sieswerda-Hoogendoorn, Tessa, E-mail: t.sieswerda@amc.nl [Section of Forensic Pediatrics, Department of Forensic Medicine, Netherlands Forensic Institute, PO Box 24044, 2490 AA The Hague (Netherlands); Department of Radiology, Academic Medical Center/Emma Children' s Hospital, Meibergdreef 9, 1105 AZ Amsterdam (Netherlands); Postema, Floor A.M., E-mail: f.a.postema@amc.nl [Faculty of Medicine, University of Amsterdam, Academic Medical Center, Meibergdreef 9, 1105 AZ Amsterdam (Netherlands); Verbaan, Dagmar, E-mail: d.verbaan@amc.nl [Department of Neurosurgery, Academic Medical Center, Meibergdreef 9, 1105 AZ Amsterdam (Netherlands); Majoie, Charles B., E-mail: c.b.majoie@amc.nl [Department of Radiology, Academic Medical Center/Emma Children' s Hospital, Meibergdreef 9, 1105 AZ Amsterdam (Netherlands); Rijn, Rick R. van, E-mail: r.r.vanrijn@amc.nl [Section of Forensic Pediatrics, Department of Forensic Medicine, Netherlands Forensic Institute, PO Box 24044, 2490 AA The Hague (Netherlands); Department of Radiology, Academic Medical Center/Emma Children' s Hospital, Meibergdreef 9, 1105 AZ Amsterdam (Netherlands)

2014-07-15

Objectives: To systematically review the literature on dating subdural hematomas (SDHs) on CT and MRI scans. Methods: We performed a systematic review in MEDLINE, EMBASE and Cochrane to search for articles that described the appearance of SDHs on CT or MRI in relation to time between trauma and scanning. Two researchers independently screened the articles, assessed methodological quality and performed data extraction. Medians with interquartile ranges were calculated. Differences were tested with a Mann–Whitney U or Kruskal–Wallis H test. Results: We included 22 studies describing 973 SDHs on CT and 4 studies describing 83 SDHs on MRI. Data from 17 studies (413 SDHs) could be pooled. There were significant differences between time intervals for the different densities on CT (p < 0.001). Time interval differed significantly between children and adults for iso- and hypodensity (p = 0.000) and hyperdensity (p = 0.046). Time interval did not differ significantly between abused and non-abused children. On MRI, time intervals for different signal intensities on T1 and T2 did not differ significantly (p = 0.108 and p = 0.194, respectively). Conclusions: Most time intervals of the different appearances of SDHs on CT and MRI are broad and overlapping. Therefore CT or MRI findings cannot be used to accurately date SDHs.

Age determination of subdural hematomas with CT and MRI: A systematic review

International Nuclear Information System (INIS)

Sieswerda-Hoogendoorn, Tessa; Postema, Floor A.M.; Verbaan, Dagmar; Majoie, Charles B.; Rijn, Rick R. van

2014-01-01

Objectives: To systematically review the literature on dating subdural hematomas (SDHs) on CT and MRI scans. Methods: We performed a systematic review in MEDLINE, EMBASE and Cochrane to search for articles that described the appearance of SDHs on CT or MRI in relation to time between trauma and scanning. Two researchers independently screened the articles, assessed methodological quality and performed data extraction. Medians with interquartile ranges were calculated. Differences were tested with a Mann–Whitney U or Kruskal–Wallis H test. Results: We included 22 studies describing 973 SDHs on CT and 4 studies describing 83 SDHs on MRI. Data from 17 studies (413 SDHs) could be pooled. There were significant differences between time intervals for the different densities on CT (p < 0.001). Time interval differed significantly between children and adults for iso- and hypodensity (p = 0.000) and hyperdensity (p = 0.046). Time interval did not differ significantly between abused and non-abused children. On MRI, time intervals for different signal intensities on T1 and T2 did not differ significantly (p = 0.108 and p = 0.194, respectively). Conclusions: Most time intervals of the different appearances of SDHs on CT and MRI are broad and overlapping. Therefore CT or MRI findings cannot be used to accurately date SDHs

Stereotactic imaging for radiotherapy: accuracy of CT, MRI, PET and SPECT

International Nuclear Information System (INIS)

Karger, Christian P; Hipp, Peter; Henze, Marcus; Echner, Gernot; Hoess, Angelika; Schad, Lothar; Hartmann, Guenther H

2003-01-01

CT, MRI, PET and SPECT provide complementary information for treatment planning in stereotactic radiotherapy. Stereotactic correlation of these images requires commissioning tests to confirm the localization accuracy of each modality. A phantom was developed to measure the accuracy of stereotactic localization for CT, MRI, PET and SPECT in the head and neck region. To this end, the stereotactically measured coordinates of structures within the phantom were compared with their mechanically defined coordinates. For MRI, PET and SPECT, measurements were performed using two different devices. For MRI, T1- and T2-weighted imaging sequences were applied. For each measurement, the mean radial deviation in space between the stereotactically measured and mechanically defined position of target points was determined. For CT, the mean radial deviation was 0.4 ± 0.2 mm. For MRI, the mean deviations ranged between 0.7 ± 0.2 mm and 1.4 ± 0.5 mm, depending on the MRI device and the imaging sequence. For PET, mean deviations of 1.1 ± 0.5 mm and 2.4 ± 0.3 mm were obtained. The mean deviations for SPECT were 1.6 ± 0.5 mm and 2.0 ± 0.6 mm. The phantom is well suited to determine the accuracy of stereotactic localization with CT, MRI, PET and SPECT in the head and neck region. The obtained accuracy is well below the physical resolution for CT, PET and SPECT, and of comparable magnitude for MRI. Since the localization accuracy may be device dependent, results obtained at one device cannot be generalized to others

Multidetector CT and MRI in diseases of the GI tract

International Nuclear Information System (INIS)

Bruel, J.M.; Gallix, B.

2003-01-01

With the introduction of spiral scanning then multidetector technologies, the accuracy for diagnosing digestive tract diseases with CT has been highly improved, and CT is used more and more in the evaluation of patients with suspected gastrointestinal disorders. CT is able to demonstrate both the intramural and the extra-mural components of the disease, and has a major role in the preoperative staging and the follow-up Improvements of CT protocols, such as CT-enteroclysis, or multiplanar 2D and 3D post-processing, including now techniques for 'virtual endoscopy', lead to discuss new indications in which CT could now compete with conventional X-rays series and video-endoscopy. This precise study of the digestive wall, the peri-digestive fat, the digestive tract blood supply, may be performed by MRI, under the condition of access to high level machines and standardized protocols. MR-enteroclysis and MR-virtual colonoscopy could be performed with much lower risk for the patient, in terms of radiation dose or contrast adverse effects. Endo-luminal coils should give to MR an ultra-high resolution for analysing the different layers of the gastrointestinal wall. Learning objectives: to review how to perform CT and MRI protocols for digestive tract imaging, to recognize the CT arid MR patterns of the main digestive tract diseases, to discuss the value, limits and role of CT and MR in digestive tract diseases, to discuss the potential role of CT and MR new technological developments for digestive tract imaging in the upcoming future Conclusion: CT is nowadays a modality of choice for digestive imaging. Improvements in technologies and indications, the necessary discussion of the risks and benefits for the patient should let the radiologists consider MRI in gastrointestinal disorders as an important part of the routine activity in clinical MRI. (authors)

Proton MRI appearance of cystic fibrosis: Comparison to CT

International Nuclear Information System (INIS)

Puderbach, Michael; Eichinger, Monika; Kauczor, Hans-Ulrich; Gahr, Julie; Mueller, Frank-Michael; Ley, Sebastian; Tuengerthal, Siegfried; Schmaehl, Astrid; Fink, Christian; Plathow, Christian; Wiebel, Matthias

2007-01-01

Cystic fibrosis (CF) is the most frequent inherited disorder leading to premature death in the Caucasian population. As life expectancy is limited by pulmonary complications, repeated imaging [chest X-ray, multislice high-resolution computed tomography (MS-HRCT)] is required in the follow-up. Magnetic resonance imaging (MRI) of the lung parenchyma is a promising new diagnostic tool. Its value for imaging lung changes caused by CF compared with CT is demonstrated. MRI performs well when compared with CT, which serves as the gold standard. Its lack in spatial resolution is obvious, but advantages in contrast and functional assessment compensate for this limitation. Thus, MRI is a reasonable alternative for imaging the CF lung and should be introduced as a radiation-free modality for follow-up studies in CF patients. For further evaluation of the impact of MRI, systematic studies comparing MRI and conventional imaging modalities are necessary. Furthermore, the value of the additional functional MRI (fMRI) information has to be studied, and a scoring system for the morphological and functional aspect of MRI has to be established. (orig.)

Membranous lipodystrophy: skeletal findings on CT and MRI

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Nwawka, O.K.; Schneider, Robert; Mintz, Douglas N. [Hospital for Special Surgery, Department of Radiology and Imaging, New York, NY (United States); Bansal, Manjula [Hospital for Special Surgery, Department of Pathology and Laboratory Medicine, New York, NY (United States); Lane, Joseph [Hospital for Special Surgery, Department of Orthopedic Surgery, New York, NY (United States)

2014-10-15

Membranous lipodystrophy, also known as Nasu-Hakola disease, is a rare hereditary condition with manifestations in the nervous and skeletal systems. The radiographic appearance of skeletal lesions has been well described in the literature. However, CT and MRI findings of lesions in the bone have not been documented to date. This report describes the radiographic, CT, MRI, and histopathologic skeletal findings in a case of membranous lipodystrophy. With corroborative pathologic findings, a diagnosis of membranous lipodystrophy on imaging allows for appropriate clinical management of disease manifestations. (orig.)

Isovaleric acidaemia: cranial CT and MRI findings

International Nuclear Information System (INIS)

Sogut, Ayhan; Acun, Ceyda; Tomsac, Nazan; Demirel, Fatma; Aydin, Kubilay; Aktuglu, Cigdem

2004-01-01

Isovaleric acidaemia is an inborn error of leucine metabolism due to deficiency of isovaleryl-CoA dehydrogenase, which results in accumulation of isovaleric acid in body fluids. There are acute and chronic-intermittent forms of the disease. We present the cranial CT and MRI findings of a 19-month-old girl with the chronic-intermittent form of isovaleric acidaemia. She presented with severe metabolic acidosis, hyperglycaemia, glycosuria, ketonuria and acute encephalopathy. Cranial CT revealed bilateral hypodensity of the globi pallidi. MRI showed signal changes in the globi pallidi and corticospinal tracts of the mesencephalon, which were hypointense on T1-weighted and hyperintense on T2-weighted images. (orig.)

Isovaleric acidaemia: cranial CT and MRI findings

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Sogut, Ayhan; Acun, Ceyda; Tomsac, Nazan; Demirel, Fatma [Department of Paediatrics, Karaelmas University, Zonguldak (Turkey); Aydin, Kubilay [Department of Radiology, Istanbul Medical School, Istanbul University, Camlikyolu, B. mehmetpasa sokak yavuz apt. No:10/10, Etiler, Istanbul (Turkey); Aktuglu, Cigdem [Department of Paediatrics, Cerrahpasa Medical School, Istanbul University, Istanbul (Turkey)

2004-02-01

Isovaleric acidaemia is an inborn error of leucine metabolism due to deficiency of isovaleryl-CoA dehydrogenase, which results in accumulation of isovaleric acid in body fluids. There are acute and chronic-intermittent forms of the disease. We present the cranial CT and MRI findings of a 19-month-old girl with the chronic-intermittent form of isovaleric acidaemia. She presented with severe metabolic acidosis, hyperglycaemia, glycosuria, ketonuria and acute encephalopathy. Cranial CT revealed bilateral hypodensity of the globi pallidi. MRI showed signal changes in the globi pallidi and corticospinal tracts of the mesencephalon, which were hypointense on T1-weighted and hyperintense on T2-weighted images. (orig.)

The value of serial FDG PET on therapeutic evaluation and relapse monitoring of lung cancer

International Nuclear Information System (INIS)

Zhu Zhaohui; Cheng Wuying; Cui Ruixue; Chen Xin; Hao Li; Dang Yonghong; Zhe Fu; Wang Bocheng

2004-01-01

Purpose: A retrospective study was designed to investigate the value of serial FDG PET on therapeutic evaluation and relapse monitoring of lung cancer, and the influence factors to the evaluation and follow-up were also analyzed. Methods: Nineteen patients with confirmed lung cancer were included in the study, and they accepted a total of 87 FDG PET scans, with 3 to 12 times for each patient. The follow-up intervals of FDG PET varied from 14 days to 32 months, and 51 of 68 intervals were within 6 months with a mean of 3.3 months. The PET images of serial studies were analyzed with both visual and semi-quantitative Methods, and they were compared with other imaging techniques (CT, MRI and/or bone scan) and clinical follow-ups. Results: By providing metabolic information, FDG PET detected tumors with high contrast to normal tissue, and the serial examinations helped 9 patients in detecting and evaluating lesions in areas with complicated anatomic structures, such as lung hilus, mediastinum, supraclavicular and abdomen. PET also showed more accuracy and sensitivity than bone scan, CT or MRI in evaluation of bone metastases in two cases. Serial FDG PET was also helpful to the cases in complicated conditions with necrosis, fibrosis or changes of anatomic structures after multiple therapies. In two cases, the follow-up studies confirmed the metastases in the incision wound, which had increasing uptake while it decreased in the repairing wound tissue. By analyzing metabolism of the lesions, PET also showed changes in 3 cases, while they were unconcluded by CT and/or MRI. In some circumstances, benign uptake of FDG influenced the evaluation and monitoring. Inflammation after radiotherapy showed high uptake in 7 cases, and influenced the evaluation of therapy in the serial examinations. Recent use of granulocyte clone stimulation factor (G-CSF) caused diffuse high uptake in bone marrow, and it covered the bone metastases in one case. And in other two cases, diffuse high

CT and MRI diagnosis of posterior fossa atypical ependymoma

International Nuclear Information System (INIS)

Yu Bolang; Zhang Ming; Luo Lin; Wang Shijie; Zhu Liping

2000-01-01

Objective: To analyse the CT and MRI features of posterior fossa atypical ependymoma. Methods: Sixteen cases of posterior fossa atypical ependymoma proved by surgery and pathology had CT and (or) MRI scanning. There were 11 males and 5 females. The age ranged from 17 to 46 (mean, 31.2). Twelve cases ranged from 20 to 40 years old. the main symptoms of all cases were dizziness, unsteady walking and vomiting. Results: The locations of all cases were cerebellum (12 cases), vermis (3 cases) and cerebellopontile angle (1 cases). Fifteen cases were solid with multiple cystic changes and 1 case in the cerebellopontile angle was cystic. The tumor was usually close to the surface of cerebellum with rather extensive connection with dura mater or tentorium. Calcifications were shown in 3 cases. The tumors revealed inhomogeneous density on CT scan and inhomogeneous intensity on MRI. Mild inhomogeneous enhancement was shown in most cases, while intense irregular enhancement in the others. Conclusions: The characteristic findings of the posterior fossa atypical ependymoma ependymoma were cerebellar intraparenchymatous multiple small cystic changes within solid tumor in most cases and inhomogeneous density and intensity on CT and MRI. The differential diagnosis is meningioma, metastasis and acoustic schwannoma

CT and MRI in progressive multifocal leukoencephalopathy

International Nuclear Information System (INIS)

Lanfermann, H.; Heindel, W.; Schroeder, R.; Lackner, K.

1994-01-01

Radiological findings and course of progressive multifocal leukoencephalopathy in 14 patients (1 woman, 13 men; 13 HIV seropositive, 1 chronic lymphatic leukaemia) were analysed retrospectively and correlated with clinical symptoms. A total of 21 CT and 16 MRI studies were evaluated. CT scans and MR images of 9 patients, which had been obtained in less than two weeks, could be compared to each other. MRI was superior to CT: 6 lesions with a diameter of 1 cm and below were not detected on CT scans, in 5 patients the extent of lesions was underestimated. Cortical involvement, mass effect or signs of atrophy were missing. Only 1 of 65 lesions showed a tiny enhancement after Gd injection. Due to the pattern and spread of lesions, which showed a close correlation to the neurologic symptoms, three different types of PML are suggested: 1. Initial precentral demyelinisation with contralateral hemiparesis (n=8); 2. lesions in temporo-occipital locations with visual disturbances (n=2); 3. predominantly bilateral lesions of cerebellar white matter with ataxia (n=4). (orig.) [de

The history, economics, and politics of CT and MRI

International Nuclear Information System (INIS)

Evens, R.G.

1989-01-01

This paper presents the historical medical background in which computed tomography (CT) has been introduced. Early investigations in CT are discussed. The clinical development of both CT and magnetic resonance imaging (MRI) is described. The economics and efficacy of both techniques is discussed and compared

CT and MRI findings in patients with neuroinfections

International Nuclear Information System (INIS)

Piekarska, A.; Zboinska, J.; Piekarski, J.

2005-01-01

Although in most patients a diagnosis of neuroinfection is not based on the results of brain imaging, there is a trend to perform MRI or CT on any patient in whom such infection is suspected. However, in selected cases, especially in patients with brain abscess or with herpetic encephalitis, brain CT and/or MRI are essential for diagnosis. Therefore we decided to analyze the results of computed tomography and magnetic resonance imaging of the brains of patients with neuroinfections and to assess the usefulness of these imaging methods in clinical practice. Brain imaging (CT and/or MRI) was performed in 106 cases (62 purulent and 44 aseptic ingoencephalitis patients). The results were analyzed in subgroups of patients with different etiology of neuroinfection. In 40 of the 58 patients (68.9%) with purulent meningoencephalitis on whom computed tomography was made, the image revealed the pathology. In the remaining 18 cases (31.1%) the results were normal. In all 4 patients on whom only MRI was done, the results were abnormal (4/4, 100%). Among the 41 patients with aseptic meningoencephalitis on whom computed tomography was done, the pathology was found in 11 (26.8%). Of the 20 patients who underwent brain MRI, the pathology was depicted in 12 (12/20, 60.0%). In 4 of the 24 patients (16.7%) with aseptic meningoencephalitis on whom only computed tomography was done, the results were abnormal. In 2 of the 3 patients (66.7%) on whom MRI was done as the only radiological examination, the results were abnormal. The pathology was found on the radiograms of 11 of the 17 patients (64.7%) in whom both imaging methods were used. In the remaining 6 of these 17 cases (6/17, 35.3%) neither CT nor MRI revealed any abnormality. Altogether, of the 44 patients with aseptic meningoencephalitis in whom brain imaging was performed, pathology was depicted in 17 (38.7%). 1. The high percentage of abnormal CT and MR images in patients with meningoencephalitis warrants the use of brain

Utility of MRI for cervical spine clearance in blunt trauma patients after a negative CT.

Science.gov (United States)

Malhotra, Ajay; Durand, David; Wu, Xiao; Geng, Bertie; Abbed, Khalid; Nunez, Diego B; Sanelli, Pina

2018-07-01

To determine the utility of cervical spine MRI in blunt trauma evaluation for instability after a negative non-contrast cervical spine CT. A review of medical records identified all adult patients with blunt trauma who underwent CT cervical spine followed by MRI within 48 h over a 33-month period. Utility of subsequent MRI was assessed in terms of findings and impact on outcome. A total of 1,271 patients with blunt cervical spine trauma underwent both cervical spine CT and MRI within 48 h; 1,080 patients were included in the study analysis. Sixty-six percent of patients with a CT cervical spine study had a negative study. Of these, the subsequent cervical spine MRI had positive findings in 20.9%; 92.6% had stable ligamentous or osseous injuries, 6.0% had unstable injuries and 1.3% had potentially unstable injuries. For unstable injury, the NPV for CT was 98.5%. In all 712 patients undergoing both CT and MRI, only 1.5% had unstable injuries, and only 0.42% had significant change in management. MRI for blunt trauma evaluation remains not infrequent at our institution. MRI may have utility only in certain patients with persistent abnormal neurological examination. • MRI has limited utility after negative cervical CT in blunt trauma. • MRI is frequently positive for non-specific soft-tissue injury. • Unstable injury missed on CT is infrequent.

MRI-guided and CT-guided cervical nerve root infiltration therapy. A cost comparison

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Maurer, M.H.; Froeling, V.; Roettgen, R.; Bucourt, M. de; Hamm, B.; Streitparth, F. [Charite University Medicine Berlin (Germany). Dept. of Diagnostic and Interventional Radiology; Bretschneider, T. [Magdeburg Univ. (Germany). Dept. of Radiology and Nuclear Medicine; Hartwig, T.; Disch, A.C. [Charite University Medicine Berlin (Germany). Center for Musculoskeletal Surgery

2014-06-15

Purpose: To evaluate and compare the costs of MRI-guided and CT-guided cervical nerve root infiltration for the minimally invasive treatment of radicular neck pain. Materials and Methods: Between September 2009 and April 2012, 22 patients (9 men, 13 women; mean age: 48.2 years) underwent MRI-guided (1.0 Tesla, Panorama HFO, Philips) single-site periradicular cervical nerve root infiltration with 40 mg triamcinolone acetonide. A further 64 patients (34 men, 30 women; mean age: 50.3 years) were treated under CT fluoroscopic guidance (Somatom Definition 64, Siemens). The mean overall costs were calculated as the sum of the prorated costs of equipment use (purchase, depreciation, maintenance, and energy costs), personnel costs and expenditure for disposables that were identified for MRI- and CT-guided procedures. Additionally, the cost of ultrasound guidance was calculated. Results: The mean intervention time was 24.9 min. (range: 12-36 min.) for MRI-guided infiltration and 19.7 min. (range: 5-54 min.) for CT-guided infiltration. The average total costs per patient were EUR 240 for MRI-guided interventions and EUR 124 for CT-guided interventions. These were (MRI/CT guidance) EUR 150/60 for equipment use, EUR 46/40 for personnel, and EUR 44/25 for disposables. The mean overall cost of ultrasound guidance was EUR 76. Conclusion: Cervical nerve root infiltration using MRI guidance is still about twice as expensive as infiltration using CT guidance. However, since it does not involve radiation exposure for patients and personnel, MRI-guided nerve root infiltration may become a promising alternative to the CT-guided procedure, especially since a further price decrease is expected for MRI devices and MR-compatible disposables. In contrast, ultrasound remains the less expensive method for nerve root infiltration guidance. (orig.)

MRI-guided and CT-guided cervical nerve root infiltration therapy. A cost comparison

International Nuclear Information System (INIS)

Maurer, M.H.; Froeling, V.; Roettgen, R.; Bucourt, M. de; Hamm, B.; Streitparth, F.; Bretschneider, T.; Hartwig, T.; Disch, A.C.

2014-01-01

Purpose: To evaluate and compare the costs of MRI-guided and CT-guided cervical nerve root infiltration for the minimally invasive treatment of radicular neck pain. Materials and Methods: Between September 2009 and April 2012, 22 patients (9 men, 13 women; mean age: 48.2 years) underwent MRI-guided (1.0 Tesla, Panorama HFO, Philips) single-site periradicular cervical nerve root infiltration with 40 mg triamcinolone acetonide. A further 64 patients (34 men, 30 women; mean age: 50.3 years) were treated under CT fluoroscopic guidance (Somatom Definition 64, Siemens). The mean overall costs were calculated as the sum of the prorated costs of equipment use (purchase, depreciation, maintenance, and energy costs), personnel costs and expenditure for disposables that were identified for MRI- and CT-guided procedures. Additionally, the cost of ultrasound guidance was calculated. Results: The mean intervention time was 24.9 min. (range: 12-36 min.) for MRI-guided infiltration and 19.7 min. (range: 5-54 min.) for CT-guided infiltration. The average total costs per patient were EUR 240 for MRI-guided interventions and EUR 124 for CT-guided interventions. These were (MRI/CT guidance) EUR 150/60 for equipment use, EUR 46/40 for personnel, and EUR 44/25 for disposables. The mean overall cost of ultrasound guidance was EUR 76. Conclusion: Cervical nerve root infiltration using MRI guidance is still about twice as expensive as infiltration using CT guidance. However, since it does not involve radiation exposure for patients and personnel, MRI-guided nerve root infiltration may become a promising alternative to the CT-guided procedure, especially since a further price decrease is expected for MRI devices and MR-compatible disposables. In contrast, ultrasound remains the less expensive method for nerve root infiltration guidance. (orig.)

Lead arthropathy: radiographic, CT and MRI findings

International Nuclear Information System (INIS)

Fernandes, Joao Luiz; Lopes Rocha, Arthemizio Antonio; Veloso Ayrimoraes Soares, Mayra; Lopes Viana, Sergio

2007-01-01

Lead arthropathy is a well-known complication of gunshot injuries with retained intra-articular bullets. Although several previous reports have discussed the radiological findings of this entity, computed tomography (CT) and magnetic resonance imaging (MRI) findings have never been described before in this setting. In this paper the authors review the imaging findings of 11 patients with lead arthropathy (1 of whom had clinical signs of lead poisoning as well), all of them studied by means of radiographs. In addition, non-enhanced CT scans were obtained in 3 patients and gadolinium-enhanced MRI in 1. Classic findings of intra-articular speckled lead deposits (occasionally with a ''lead arthrogram'' appearance), joint space narrowing and preserved bone density were found at radiographs in the great majority of cases. Furthermore, extension of intra-articular lead to adjacent tendon sheaths was observed in almost half of the patients, an observation rarely reported in the literature. CT scans and MRI, in their turn, were superior with regard to soft tissue abnormalities, accurately depicting joint effusion and the thickened synovium with lead particles embedded in it. Post-gadolinium MRI had the advantage of showing the enhancement pattern of the inflamed synovium and associated bone marrow edema pattern. Although it is not possible to establish the role of axial imaging in lead arthropathy from the small number of cases studied, this initial experience shows that both methods hold promise in this setting and may be useful, at least in selected cases. (orig.)

Serial CT scans and Menkes' kinky hair disease

International Nuclear Information System (INIS)

Nakada, Eizo; Kameyama, Junji; Yoshimitsu, Hajime; Mori, Mikio; Tanaka, Mutsuo; Yoshimitsu, Kazunori.

1988-01-01

Menkes' kinky hair disease is a sex-linked recessive disorder of copper metabolism, characterized by progressive psychomotor deterioration, seizures, and peculiar hair structure. We examined serial CT scans of patients with this disease. A 2,210-g male infant was delivered after an uneventful gestation of 36 weeks. His one-minute Apgar score was 9. His uncle had died at 1 year of age. His first cousin was also diagnosed as having Menkes' kinky hair disease when our patient was 2 years old. Shortly after birth he had mild respiratory distress. At 5 days of age, he developed setting-sun signs. The first CT scan, at 10 days of age, revealed mild posterior fossa hemorrhages. At 3 months of age, myoclonic seizures began, and the CT scan revealed subdural effusion and mild brain atrophy. The seizures were controllable by using phenobarbital, valproic acid, and nitrazepam. He did not follow light or a fixate, but the fundi were normal. He was diffusely hypotonic. At 9 months of age, the seizures became uncontrollable. The CT scans at 15 and 31 months of age showed subdural hemorrhage and/or brain atrophy. At 15 months of age, the serum copper level was 42 μ g/dl, while the serum ceruloplasmin level was 3.2 mg/dl. He exhibited severe developmental failure. At 4 years of age, he died. (author)

Diagnosis of intracranial mixed tumor with CT and MRI (report of 7 cases)

International Nuclear Information System (INIS)

Guan Changqun; Zhou Huaiwei; Xue Hongli; Zhang Yuzhong; Hu Lianyuan

1998-01-01

Purpose: To recognize the images of intracranial mixed tumor. Materials and methods: Seven cases were studied with CT and MRI. All were proved by pathology, including mixed tumor of meningioma with glioblastoma 2 cases, meningioma with pituitary tumor 2 cases, glioblastoma multiform with angioblastoma 1 cases, cholesteatoma with melanoma 1 case, and pituitary tumor with meningioma 1 case. The authors analysed the CT and MRI manifestations of intracranial mixed tumor retrospectively. Results: The CT and MRI manifestations of intracranial mixed tumor were exactly like meningioma, glioma, and hypophysoma, etc, therefore it was usually misdiagnosed the common tumor. Four cases intracranial mixed tumor displayed two kinds of characteristic CT and MRI manifestation on the same region of the same tumor in contrast with the clinic and pathologic change. Conclusion: There were no characteristic CT and MRI manifestations; the diagnosis should be made in combination with clinical information

Visual analysis of serial T2-weighted MRI in multiple sclerosis: intra- and interobserver reproducibility

International Nuclear Information System (INIS)

Molyneux, P.D.; Miller, D.H.; Filippi, M.; Yousry, T.A.; Radue, E.W.; Ader, H.J.; Barkhof, F.

1999-01-01

We evaluated the effect of consensus formation and training on the agreement between observers in scoring the number of new and enlarging multiple sclerosis (MS) lesions on serial T2-weighted MRI studies. The baseline and month 9 MRI studies of 16 patients with a range of MRI activity were used (dual-echo conventional spin-echo sequence, TR 2000, TE 34 and 90 ms, 5 mm contiguous slices, in-plane resolution 1 mm). First, the serial studies were visually analysed for the presence of new and enlarging lesions, on two occasions, by five experienced observers, without adopting any consensus strategy and in isolation. Next, the observers met to identify the common sources of inconsistencies in reporting between observers and formulate consensus rules. Finally, a further independent reading session was performed on the same MRI dataset, this time applying the consensus rules. Agreement between observers was assessed using kappa scores. Without the consensus rules, interobserver kappa scores for the first and second reading sessions for new lesions were only 0.51 and 0.39 respectively; agreement for enlarging lesions was even worse. The mean intraobserver kappa score for new lesions was higher at 0.72, reflecting the fact that the observers were consistently applying their individual assessment strategies. Application of the consensus rules did not lead to a significant improvement in inter observer kappas; the kappa scores adopting the guidelines were 0.46 and 0.21 for new and enlarging lesions respectively. Consensus guidelines thus did not improve the reproducibility of visual analysis of serial T2-weighted MRI, and the level of agreement between observers remained only moderate. Suboptimal repositioning is likely to be a major source of residual variability and this suggests a future role for image registration strategies; until then, a single observer, or pair of observers working in consensus, should be used in MS studies. (orig.)

Quantitative 3D ultrashort time-to-echo (UTE) MRI and micro-CT (μCT) evaluation of the temporomandibular joint (TMJ) condylar morphology

Energy Technology Data Exchange (ETDEWEB)

Geiger, Daniel [Sapienza University of Rome, Department of Radiological, Oncological and Pathological Sciences, Rome (Italy); Bae, Won C.; Statum, Sheronda; Du, Jiang; Chung, Christine B. [University of California-San Diego, Department of Radiology, San Diego, CA (United States)

2014-01-15

Temporomandibular dysfunction involves osteoarthritis of the TMJ, including degeneration and morphologic changes of the mandibular condyle. The purpose of this study was to determine the accuracy of novel 3D-UTE MRI versus micro-CT (μCT) for quantitative evaluation of mandibular condyle morphology. Nine TMJ condyle specimens were harvested from cadavers (2 M, 3 F; age 85 ± 10 years, mean ± SD). 3D-UTE MRI (TR = 50 ms, TE = 0.05 ms, 104-μm isotropic-voxel) was performed using a 3-T MR scanner and μCT (18-μm isotropic-voxel) was also performed. MR datasets were spatially registered with a μCT dataset. Two observers segmented bony contours of the condyles. Fibrocartilage was segmented on the MR dataset. Using a custom program, bone and fibrocartilage surface coordinates, Gaussian curvature, volume of segmented regions, and fibrocartilage thickness were determined for quantitative evaluation of joint morphology. Agreement between techniques (MRI vs. μCT) and observers (MRI vs. MRI) for Gaussian curvature, mean curvature, and segmented volume of the bone were determined using intraclass correlation coefficient (ICC) analysis. Between MRI and μCT, the average deviation of surface coordinates was 0.19 ± 0.15 mm, slightly higher than the spatial resolution of MRI. Average deviation of the Gaussian curvature and volume of segmented regions, from MRI to μCT, was 5.7 ± 6.5 % and 6.6 ± 6.2 %, respectively. ICC coefficients (MRI vs. μCT) for Gaussian curvature, mean curvature, and segmented volumes were 0.892, 0.893, and 0.972, respectively. Between observers (MRI vs. MRI), the ICC coefficients were 0.998, 0.999, and 0.997, respectively. Fibrocartilage thickness was 0.55 ± 0.11 mm, as previously described in the literature for grossly normal TMJ samples. 3D-UTE MR quantitative evaluation of TMJ condyle morphology ex-vivo, including surface, curvature, and segmented volume, shows high correlation against μCT and between observers. In addition, UTE MRI allows

CT and MRI of haemorrhage into intracranial neuromas

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Asari, S. (Dept. of Neurological Surgery, Okayama Univ. Medical School, Okayama City (Japan)); Katayama, S. (Dept. of Neurological Surgery, Okayama Univ. Medical School, Okayama City (Japan)); Itoh, T. (Dept. of Neurological Surgery, Okayama Univ. Medical School, Okayama City (Japan)); Tsuchida, S. (Dept. of Neurological Surgery, Okayama Univ. Medical School, Okayama City (Japan)); Ohmoto, T. (Dept. of Neurological Surgery, Okayama Univ. Medical School, Okayama City (Japan))

1993-04-01

Six patients with haemorrhage into intracranial neuromas were studied by computed tomography (CT) and magnetic resonance imaging (MRI) at 0.5 T with spin-echo pulse sequences. The nature of the tumour and the presence of a haematoma were confirmed by surgery and microscopic examination in all cases. Four neuromas arose from the acoustic nerves and two from the trigeminal. Four of the six patients suffered from sudden onset or rapid worsening of symptoms including headache, vertigo and/or hemifacial motor and sensory disturbances. CT in the acute stage revealed a hyperdense area or a fluid-fluid level (FFL). The hyperdense area disappeared on CT repeated in the chronic stage. On MRI in subacute and chronic stages the haemorrhage showed hyperintensity on both T1 and T2 weighting in five cases examined between 16 and 46 days after the onset, and isointensity on T1 weighting and an FFL on T2 weighting in one case examined 12 days after the onset of symptoms. A well-defined low intensity rim indicating prior haemorrhage was observed on T2-weighted images in three cases. MRI was more effectie than CT in detecting haemorrhage into the tumours and in staging it. (orig.)

MRI of patients with cerebral palsy and normal CT scan

International Nuclear Information System (INIS)

Bogaert, P. van; Szliwowski, H.B.

1992-01-01

Three children with clinical evidence of cerebral palsy (CP) and normal cerebral computed tomography (CT) scans were evaluated by magnetic resonance imaging (MRI) to identify CT-undetectable white matter lesions in the watershed zones of arterial territories. The two patients with spastic diplegia showed bilateral lesions either in the subcortical regions or in the occipital periventricular regions. The patient with congenital hemiplegia exhibited unilateral lesions in the periventricular region. We conclude that MRI is more informative than CT for the evaluation of patients with CP. (orig.)

MRI of patients with cerebral palsy and normal CT scan

Energy Technology Data Exchange (ETDEWEB)

Bogaert, P. van; Szliwowski, H.B. (Hopital Erasme, Brussels (Belgium). Dept. of Neurology); Baleriaux, D.; Christophe, C. (Hopital Erasme, Brussels (Belgium). Dept. of Radiology (Neuroradiology))

1992-02-01

Three children with clinical evidence of cerebral palsy (CP) and normal cerebral computed tomography (CT) scans were evaluated by magnetic resonance imaging (MRI) to identify CT-undetectable white matter lesions in the watershed zones of arterial territories. The two patients with spastic diplegia showed bilateral lesions either in the subcortical regions or in the occipital periventricular regions. The patient with congenital hemiplegia exhibited unilateral lesions in the periventricular region. We conclude that MRI is more informative than CT for the evaluation of patients with CP. (orig.).

Magnetic resonance imaging (MRI) in diffuse liver diseases. Comparison with CT

Energy Technology Data Exchange (ETDEWEB)

Yoshikawa, Masaharu; Ebara, Masaaki; Ohto, Masao

1987-06-01

MRI (Magnetic Resonance Imaging) was performed in 74 patients with chronic hepatitis, liver cirrhosis, idiopathic portal hypertension, Budd-Chiari syndrome, extrahepatic protal vein occlusion, Wilson disease and hemochromatosis. We measured relaxation time of the liver and the spleen in these patients and compared MRI with CT in the diagnostic capability. MRI was superior to plain CT in the detection of collateral vessels in liver cirrhosis and extrahepatic protal vein occlusion. MRI could also demonstrate the occluded part of the inferior vena cava in Budd-Chiari syndrome. However, MRI was almost the same as CT in the visualization of the hepatic configuration in liver cirrhosis. In liver cirrhosis, T1 values of the liver and the spleen were longer than those in normal controls, and T1 values of the liver were correlated with ICG R-15. Hepatic T1 values in Budd-Chiari syndrome were longer than those in normal controls.

CT and MRI diagnosis of acute hepatic injury

International Nuclear Information System (INIS)

Wang Rengui; Fumio Yamamoto; Pu Yonglin; Gao Yujie.

1997-01-01

To evaluate and compare MR and CT in diagnosis of acute traumatic hepatic laceration, ten patients with acute hepatic rupture underwent CT scan and/or MRI in the first 24 hours after injury. The injury was graded as mild ( 50% of one lobe). In the first 24 hours after injury, 33.3% (3/9) and 28.6%(2/7) of the hepatic injury demonstrated isodensity and isointensity on plain CT scan and T 1 -weighted images. All the lesions (100%) were clearly identified as marked hyperintensity on T 2 -weighted images. On T 2 WI, T 1 WI and non-contrast CT, 100%, 57.1% and 55.6% of the acute hepatic injuries could be graded respectively. Delayed complications occurred in four patients with deep hepatic injury about 1 to 3 weeks after injury. T 2 -weighted MR imaging is more sensitive and useful for detection of the type and severity of acute hepatic rupture. Follow-up MRI or CT within the first few weeks after injury is needed in patients with deep hepatic injury for detection of delayed complications

WE-AB-202-07: Ventilation CT: Voxel-Level Comparison with Hyperpolarized Helium-3 & Xenon-129 MRI

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Tahir, B; Marshall, H; Hughes, P; Stewart, N; Horn, F; Collier, G; Norquay, G; Hart, K; Swinscoe, J; Hatton, M; Wild, J; Ireland, R [University of Sheffield, Sheffield (United Kingdom)

2016-06-15

Purpose: To compare the spatial correlation of ventilation surrogates computed from inspiratory and expiratory breath-hold CT with hyperpolarized Helium-3 & Xenon-129 MRI in a cohort of lung cancer patients. Methods: 5 patients underwent expiration & inspiration breath-hold CT. Xenon-129 & {sup 1}H MRI were also acquired at the same inflation state as inspiratory CT. This was followed immediately by acquisition of Helium-3 & {sup 1}H MRI in the same breath and at the same inflation state as inspiratory CT. Expiration CT was deformably registered to inspiration CT for calculation of ventilation CT from voxel-wise differences in Hounsfield units. Inspiration CT and the Xenon-129’s corresponding anatomical {sup 1}H MRI were registered to Helium-3 MRI via the same-breath anatomical {sup 1}H MRI. This enabled direct comparison of CT ventilation with Helium-3 MRI & Xenon-129 MRI for the median values in corresponding regions of interest, ranging from finer to coarser in-plane dimensions of 10 by 10, 20 by 20, 30 by 30 and 40 by 40, located within the lungs as defined by the same-breath {sup 1}H MRI lung mask. Spearman coefficients were used to assess voxel-level correlation. Results: The median Spearman’s coefficients of ventilation CT with Helium-3 & Xenon-129 MRI for ROIs of 10 by 10, 20 by 20, 30 by 30 and 40 by 40 were 0.52, 0.56, 0.60 and 0.68 and 0.40, 0.42, 0.52 and 0.70, respectively. Conclusion: This work demonstrates a method of acquiring CT & hyperpolarized gas MRI (Helium-3 & Xenon-129 MRI) in similar breath-holds to enable direct spatial comparison of ventilation maps. Initial results show moderate correlation between ventilation CT & hyperpolarized gas MRI, improving for coarser regions which could be attributable to the inherent noise in CT intensity, non-ventilatory effects and registration errors at the voxel-level. Thus, it may be more beneficial to quantify ventilation at a more regional level.

PET / MRI vs. PET / CT. Indications Oncology

International Nuclear Information System (INIS)

Oliva González, Juan P.

2016-01-01

Hybrid techniques in Nuclear Medicine is currently a field in full development for diagnosis and treatment of various medical conditions. With the recent advent of PET / MRI much it speculated about whether or not it is superior to PET / CT especially in oncology. The Conference seeks to clarify this situation by dealing issues such as: State of the art technology PET / MRI; Indications Oncology; Some clinical cases. It concludes by explaining the oncological indications of both the real and current situation of the PET / MRI. (author)

Serial dynamic CT scan in patients with acute basal ganglia infarctions

International Nuclear Information System (INIS)

Node, Yoji; Nakazawa, Shozo; Tsuji, Yukihide.

1987-01-01

Dynamic computed tomography (CT) was performed on 15 patients (37 to 93 years of age) with acute basal ganglia infarctions, and the perfusion patterns of the infarcted regions on CT were evaluated. The initial dynamic CT was performed within 12 hours after onset, while the serial studies of the dynamic CT were performed on the 3rd and 7th days. The left-over-right ratio in the peak value in the basal ganglia in 15 normal subjects was 1.01 ± 0.03 (mean ± SD), so there were no differences in the peak values of the bilateral basal ganglia. We also examined the left-over-right ratio in the peak value and in the rapid-washout ratio in the basal ganglia in the 15 normal subjects. There was no difference in the peak values of the bilateral basal ganglia. The mean rapid-washout ratio was 0.62 ± 0.11 (mean ± SD). The prognoses of these patients three months after onset were as follows: 8 showed a good recovery, 5 had a moderate disability, and 2 had a severe disability. The perfusions on admission were as follows. 10 were hypoperfusions, 3 were hypo + late perfusions, one was a normoperfusion, and one was a late perfusion. There was a tendency for the rapid-washout ratio decrease more in the hypo + late perfusion group than in the other groups. Twelve patients showed an iso-density, while 3 showed a low density, on admission. The ''low-density'' group showed a decrease in the A/N ratio of the peak value. We performed serial dynamic CT in 11 cases. The group with severe disabilities (2 cases) showed a hypo + late perfusion in the initial CT, one case kept a hypo + late perfusion, and another case changed to a hypoperfusion; also, there was a tendency for there to be a poor improvement in the A/N ratio of the peak value in these two ''severe-disability'' patients. (J.P.N.)

Imaging with 124I in differentiated thyroid carcinoma: is PET/MRI superior to PET/CT?

International Nuclear Information System (INIS)

Binse, I.; Poeppel, T.D.; Ruhlmann, M.; Gomez, B.; Bockisch, A.; Rosenbaum-Krumme, S.J.; Umutlu, L.

2016-01-01

The aim of this study was to compare integrated PET/CT and PET/MRI for their usefulness in detecting and categorizing cervical iodine-positive lesions in patients with differentiated thyroid cancer using 124 I as tracer. The study group comprised 65 patients at high risk of iodine-positive metastasis who underwent PET/CT (low-dose CT scan, PET acquisition time 2 min; PET/CT 2 ) followed by PET/MRI of the neck 24 h after 124 I administration. PET images from both modalities were analysed for the numbers of tracer-positive lesions. Two different acquisition times were used for the comparisons, one matching the PET/CT 2 acquisition time (2 min, PET/MRI 2 ) and the other covering the whole MRI scan time (30 min, PET/MRI 30 ). Iodine-positive lesions were categorized as metastasis, thyroid remnant or inconclusive according to their location on the PET/CT images. Morphological information provided by MRI was considered for evaluation of lesions on PET/MRI and for volume information. PET/MRI 2 detected significantly more iodine-positive metastases and thyroid remnants than PET/CT 2 (72 vs. 60, p = 0.002, and 100 vs. 80, p = 0.001, respectively), but the numbers of patients with at least one tumour lesion identified were not significantly different (21/65 vs. 17/65 patients). PET/MRI 30 tended to detect more PET-positive metastases than PET/MRI 2 (88 vs. 72), but the difference was not significant (p = 0.07). Of 21 lesions classified as inconclusive on PET/CT, 5 were assigned to metastasis or thyroid remnant when evaluated by PET/MRI. Volume information was available in 34 % of iodine-positive metastases and 2 % of thyroid remnants on PET/MRI. PET/MRI of the neck was found to be superior to PET/CT in detecting iodine-positive lesions. This was attributed to the higher sensitivity of the PET component, Although helpful in some cases, we found no substantial advantage of PET/MRI over PET/CT in categorizing iodine-positive lesions as either metastasis or thyroid remnant

PET/MRI and PET/CT in advanced gynaecological tumours: initial experience and comparison

Energy Technology Data Exchange (ETDEWEB)

Queiroz, Marcelo A.; Schulthess, Gustav von; Veit-Haibach, Patrick [University Hospital Zurich, Department Medical Radiology, Nuclear Medicine, Zurich (Switzerland); University Hospital Zurich, Department Medical Radiology, Diagnostic and Interventional Radiology, Zurich (Switzerland); University of Zurich, Zurich (Switzerland); Kubik-Huch, Rahel A.; Freiwald-Chilla, Bianka [Kantonsspital Baden AG, Department of Radiology, Baden (Switzerland); Hauser, Nik [Kantonsspital Baden AG, Department of Gynaecology, Baden (Switzerland); Froehlich, Johannes M. [Guerbet AG, Zurich (Switzerland)

2015-08-15

To compare the diagnostic accuracy of PET/MRI and PET/CT for staging and re-staging advanced gynaecological cancer patients as well as identify the potential benefits of each method in such a population. Twenty-six patients with suspicious or proven advanced gynaecological cancer (12 ovarian, seven cervical, one vulvar and four endometrial tumours, one uterine metastasis, and one primary peritoneal cancer) underwent whole-body imaging with a sequential trimodality PET/CT/MR system. Images were analysed regarding primary tumour detection and delineation, loco-regional lymph node staging, and abdominal/extra-abdominal distant metastasis detection (last only by PET/CT). Eighteen (69.2 %) patients underwent PET/MRI for primary staging and eight patients (30.8 %) for re-staging their gynaecological malignancies. For primary tumour delineation, PET/MRI accuracy was statistically superior to PET/CT (p < 0.001). Among the different types of cancer, PET/MRI presented better tumour delineation mainly for cervical (6/7) and endometrial (2/3) cancers. PET/MRI for local evaluation as well as PET/CT for extra-abdominal metastases had therapeutic consequences in three and one patients, respectively. PET/CT detected 12 extra-abdominal distant metastases in 26 patients. PET/MRI is superior to PET/CT for primary tumour delineation. No differences were found in detection of regional lymph node involvement and abdominal metastases detection. (orig.)

Serial CT scans of cerebral hypoxia due to prolonged status epilepticus

Energy Technology Data Exchange (ETDEWEB)

Saiwai, Shigeo; Matsumura, Yasumasa; Tamaoka, Koichi; Fukuda, Teruo; Miyamoto, Takeshi [Kobe Central Municipal Hospital, Kobe (Japan)

1983-04-01

Serial computed tomography (CT) scans of 5 infants with status epilepticus were reviewed. Four out of the 5 infants fortunately had CT scans before status epilepticus because of a convulsion. There was a diffuse and mild low density in the hemisphere, with small ventricles and tight sulci (brain swelling) at 1 to 2 days after ictus. Thereafter, a diffuse low density became apparent except for the cerebellum, the brain stem, the thalamus, and the basal ganglia. Two to 4 weeks after ictus, a localized, mottled low density was demonstrated on the cerebral mantle and atrophic changes became progressively clear. In 3 cases, no abnormal enhancement was elicited on contrast CT scans performed between 5 to 16 days after status epilepticus. We discussed the possible pathophysiological aspects of the brain damage due to ''prolonged status epilepticus.''

Patch-based generation of a pseudo CT from conventional MRI sequences for MRI-only radiotherapy of the brain

DEFF Research Database (Denmark)

Andreasen, Daniel; Van Leemput, Koen; Hansen, Rasmus H.

2015-01-01

scans. In this study, we investigate the potential of a patch-based method for creating a pCT based on conventional T1-weighted MRI scans without using deformable registrations. We compare this method against two state-of-the-art methods within the voxel-based and atlas-based categories. Methods...... based on water equivalent path lengths was carried out, comparing the upper hemisphere of the head in the pCT and the real CT. Finally, the dosimetric accuracy was tested and compared for a photon treatment plan. Results:The pCTs produced with the patch-based method had the best voxel-wise, geometric......Purpose: In radiotherapy (RT) based on magnetic resonance imaging (MRI) as the only modality, the information on electron density must be derived from the MRI scan by creating a so-called pseudo computed tomography (pCT). This is a nontrivial task, since the voxel-intensities in an MRI scan...

CT and MRI analysis of central nervous system Rosai-Dorfman disease

International Nuclear Information System (INIS)

Zhang Jiatang; Lang Senyang; Pu Chuanqiang; Zhu Ruyuan; Wang Dianjun

2008-01-01

Objective: To study the CT and MRI imaging features of central nervous system Rosai-Dorfman disease and to enhance knowledge and differential diagnostic ability for central nervous system Rosai-Doffman disease. Methods: The CT and MRI imaging appearances in 4 cases of pathologically proven Rosai-Dorfman disease were retrospectively evaluated and the literature of central nervous system Rosai- Dorfman disease were reviewed. Results: Two cases had cranial CT scans, 4 cases had cranial MRI scans. On CT scans, cerebral edema was demonstrated in one case and the other case was normal. MRI scans showed the lesions were solitary in saddle area in 3 cases, and multiple in anterior cranial fossa in 1 case. The lesions exhibited iso- to hypointensity on both T 1 WI and T 2 WI images. Following intravenous injection of contrast medium, ring-like enhancement was seen in 2 cases and homogeneous enhancement in 1 case. Nodular enhancement was seen in the case of multiple lesions in the anterior cranial fossa. All lesions were dural-based. Conclusions: In patients with fever, headache, elevation of the erythrocyte sedimentation rate (ESR) and a polyclonal increase in γ-globulins, the possibility of central nervous system Rosai-Dorfman disease should be considered when single or multiple dural-based mass lesions, especially in sellar region, were identified by CT and MRI. (authors)

Atlas-guided generation of pseudo-CT images for MRI-only and hybrid PET-MRI-guided radiotherapy treatment planning

Science.gov (United States)

Arabi, Hossein; Koutsouvelis, Nikolaos; Rouzaud, Michel; Miralbell, Raymond; Zaidi, Habib

2016-09-01

Magnetic resonance imaging (MRI)-guided attenuation correction (AC) of positron emission tomography (PET) data and/or radiation therapy (RT) treatment planning is challenged by the lack of a direct link between MRI voxel intensities and electron density. Therefore, even if this is not a trivial task, a pseudo-computed tomography (CT) image must be predicted from MRI alone. In this work, we propose a two-step (segmentation and fusion) atlas-based algorithm focusing on bone tissue identification to create a pseudo-CT image from conventional MRI sequences and evaluate its performance against the conventional MRI segmentation technique and a recently proposed multi-atlas approach. The clinical studies consisted of pelvic CT, PET and MRI scans of 12 patients with loco-regionally advanced rectal disease. In the first step, bone segmentation of the target image is optimized through local weighted atlas voting. The obtained bone map is then used to assess the quality of deformed atlases to perform voxel-wise weighted atlas fusion. To evaluate the performance of the method, a leave-one-out cross-validation (LOOCV) scheme was devised to find optimal parameters for the model. Geometric evaluation of the produced pseudo-CT images and quantitative analysis of the accuracy of PET AC were performed. Moreover, a dosimetric evaluation of volumetric modulated arc therapy photon treatment plans calculated using the different pseudo-CT images was carried out and compared to those produced using CT images serving as references. The pseudo-CT images produced using the proposed method exhibit bone identification accuracy of 0.89 based on the Dice similarity metric compared to 0.75 achieved by the other atlas-based method. The superior bone extraction resulted in a mean standard uptake value bias of  -1.5  ±  5.0% (mean  ±  SD) in bony structures compared to  -19.9  ±  11.8% and  -8.1  ±  8.2% achieved by MRI segmentation-based (water

Serial neuroradiological studies in focal cerebritis

International Nuclear Information System (INIS)

Hatta, S.; Mochizuki, H.; Kuru, Y.; Miwa, H.; Kondo, T.; Mori, H.; Mizuno, Y.

1994-01-01

We report serial neuroradiological studies in a patient with focal cerebritis in the head of the left caudate nucleus. On the day after the onset of symptoms, CT showed an ill-defined low density lesion. The lack of contrast enhancement appeared to be the most important finding for differentiating focal cerebritis from an encapsulated brain abscess or a tumour. MRI two days later revealed the centre of the lesion to be of slightly low intensity on T1-weighted inversion recovery (IR) images and very low intensity on T2-weighted spin echo images, which appeared to correspond to the early cerebritis stage of experimentally induced cerebritis and brain abscess. Ten days after the onset of symptoms, CT revealed a thin ring of enhancement in the head of the caudate nucleus, and a similar small ring was seen in the hypothalamus 16 days after the onset, corresponding to the late cerebritis stage. MRI nine days later revealed ill-defined high signal lesions within the involved area on the T1-weighted IR images. To our knowledge, this is the first published MRI documentation of the early cerebritis stage developing into an encapsulated brain abscess. The mechanisms underlying of these radiographic changes are discussed. (orig.)

Precise fusion of MRI and dual energy 111In WBC/99mTc HDP SPECT/CT in the diabetic foot using companion CT: an example of SPECT/MRI imaging

International Nuclear Information System (INIS)

Knešaurek, K.; Heiba, S.; Kolker, D.; Vatti, S.

2015-01-01

The purpose of our study was to correctly fuse MRI and SPECT 111 In WBC and 99m Tc HDP images using companion CT images. The fused images could be used to assess proper surgical approach in treatment of the diabetic foot. Nine patients who had dual energy 111 In WBC/ 99 m Tc HDP SPECT/CT and MRI studies within a week were investigated in an ongoing project. A GE Infinia SPECT/CT camera and Siemens MAGNETOM 1.5T MR system were used in this study. First, the MRI and corresponding CT images were coregistrated using a transformation based on normalized mutual information. The transformation was saved and used for MRI and 111 In WBC/ 99 m Tc HDP SPECT fusion. A Jaszczak phantom study was also performed in order to estimate accuracy of MRI/ SPECT fusion. The Jaszczak phantom study with 3.7 MBq 111 In hot sphere showed that MRI/SPECT alignment using the approach described above produced registration with 0.7±0.4 mm accuracy in all three dimensions (3D). The nine clinical cases were visually evaluated and showed 1-2 mm 3D fusion accuracy. MRI provides almost perfect anatomy of soft tissue and bony structures but it may exaggerate the extent of infection. 111 In WBC/ 99 m Tc HDP SPECT imaging is more accurate for infection detection but lacks anatomical reference. Combination of these images proved an essential adjunct to diagnosis. A clinical utility of the approach is illustrated in two clinical examples. In conclusion, the CT in dual energy 111 In WBC/ 99 m Tc HDP SPECT/CT studies can be used to accurately fuse and compare 111 In WBC/ 99 m Tc HDP SPECT and MRI images of the diabetic foot. This can significantly help in conservative treatment planning and limb salvage procedures in treatment of diabetic foot infections.

MRI and CT contrast media extravasation

Science.gov (United States)

Heshmatzadeh Behzadi, Ashkan; Farooq, Zerwa; Newhouse, Jeffery H.; Prince, Martin R.

2018-01-01

Abstract Background: This systematic review combines data from multiple papers on contrast media extravasation to identify factors contributing to increased extravasation risk. Methods: Data were extracted from 17 papers reporting 2191 extravasations in 1,104,872 patients (0.2%) undergoing computed tomography (CT) or magnetic resonance imaging (MRI). Results: Extravasation rates were 0.045% for gadolinium-based contrast agents (GBCA) and nearly 6-fold higher, 0.26% for iodinated contrast agents. Factors associated with increased contrast media extravasations included: older age, female gender, using an existing intravenous (IV) instead of placing a new IV in radiology, in-patient status, use of automated power injection, high injection rates, catheter location, and failing to warm up the more viscous contrast media to body temperature. Conclusion: Contrast media extravasation is infrequent but nearly 6 times less frequent with GBCA for MRI compared with iodinated contrast used in CT. PMID:29489663

Tuberculous adenitis: comparison of CT and MRI findings with histopathological features

International Nuclear Information System (INIS)

Backer, A.I. de; Mortele, K.J.; Heuvel, E. van den; Vanschoubroeck, I.J.; Kockx, M.M.; Vyvere, M. van de

2007-01-01

Our aim was to investigate the relationship between the various histopathological features and the CT and MRI findings in routinely submitted histopathological specimens for the diagnosis of tuberculous lymphadenopathy. Twelve formalin-fixed, paraffin-embedded tissue blocks from ten patients who were clinically suspected of having tuberculous lymphadenopathy were evaluated. We assessed the presence of histopathological features including granuloma formation, caseous necrosis, and presence of Langhans-type giant cells, calcifications, fibrosis or normal lymphoid tissue. We performed polymerase chain reaction (PCR)-based assay for mycobacterial DNA and Ziehl-Neelsen staining for acid-fast bacilli (AFB). Findings were compared with those of CT and MRI, including signal intensities on unenhanced MR images, lymph node homogeneity, attenuation values on contrast-enhanced CT and enhancement patterns on MRI. Based on CT and MRI findings, four lymph node types could be defined: (1) homogeneous nodes, visible on both pre- and post-contrast images and corresponding histopathologically to granulation tissue without or with minimal caseation necrosis (n = 2); (2) heterogeneous nodes, showing heterogeneous enhancement patterns with central non-enhancing areas and corresponding to minor or moderate intranodal caseation/liquefaction necrosis (n = 3); (3) nodes showing peripheral rim enhancement and corresponding to moderate or extensive intranodal caseation/liquefaction necrosis (n = 5); (4) heterogeneous nodes showing intranodal hyperdensities on CT and hypointense areas on T1- and T2-weighted images and corresponding to fibrosis and calcifications (n = 2). On CT and MRI, the findings reflect different stages of the tuberculous process. Imaging findings depend on the presence and the degree of granuloma formation, caseation/liquefaction necrosis, fibrosis and calcifications. (orig.)

Metastatic liver tumor from cystic ovarian carcinomas. CT and MRI appearance

Energy Technology Data Exchange (ETDEWEB)

Tang, Yi; Yamashita, Yasuyuki; Ogata, Ichiro; Namimoto, Tomohiro; Abe, Yasuko; Urata, Joji; Takahashi, Mutsumasa [Kumamoto Univ. (Japan). School of Medicine

1999-08-01

The initial and follow-up CT and MRI images of ten patients with hepatic metastases from ovarian tumors were retrospectively analyzed to establish their features and sequential changes in appearance. Ten patients with hepatic metastasis from ovarian tumors received initial and follow-up CT and MRI examinations. Six patients were followed up every two to three weeks before surgical tumor resection. Both CT and MR images were analyzed by two radiologists. A total of fourteen lesions were detected by CT and MRI in 10 patients. All 14 lesions were demonstrated as areas of marked hyperintensity on T2-weighted MRI. Eleven cyst-like tumors were demonstrated as round or oval low density lesions on CT and as areas of hypointensity on T1-weighted imaging. Three lesions were shown as solid masses with slightly low attenuation at the initial CT examination and slightly low or iso-intensity areas on T1-weighted imaging, and these lesions showed early peripheral globular enhancement and delayed enhancement on contrast-enhanced CT and MR imaging. Cystic formation was observed two to three weeks later after initial study in all the 3 solid lesions. Rapid subcapsular effusion, which showed obvious enhancement on delayed Gd-DTPA enhanced MR imaging, was observed in two patients. The hepatic metastatic tumor from cystic ovarian carcinoma may manifest as a well-defined cystic lesion or as a solid mass, and the solid mass shows delayed enhancement on contrast-enhanced CT and MR imaging. Furthermore, rapid cystic formation and rapid subcapsular extension is frequently seen. (author)

[18F]FDG PET/CT outperforms [18F]FDG PET/MRI in differentiated thyroid cancer

International Nuclear Information System (INIS)

Vrachimis, Alexis; Wenning, Christian; Weckesser, Matthias; Stegger, Lars; Burg, Matthias Christian; Allkemper, Thomas; Schaefers, Michael

2016-01-01

To evaluate the diagnostic potential of PET/MRI with [ 18 F]FDG in comparison to PET/CT in patients with differentiated thyroid cancer suspected or known to have dedifferentiated. The study included 31 thyroidectomized and remnant-ablated patients who underwent a scheduled [ 18 F]FDG PET/CT scan and were then enrolled for a PET/MRI scan of the neck and thorax. The datasets (PET/CT, PET/MRI) were rated regarding lesion count, conspicuity, diameter and characterization. Standardized uptake values were determined for all [ 18 F]FDG-positive lesions. Histology, cytology, and examinations before and after treatment served as the standards of reference. Of 26 patients with a dedifferentiated tumour burden, 25 were correctly identified by both [ 18 F]FDG PET/CT and PET/MRI. Detection rates by PET/CT and PET/MRI were 97 % (113 of 116 lesions) and 85 % (99 of 113 lesions) for malignant lesions, and 100 % (48 of 48 lesions) and 77 % (37 of 48 lesions) for benign lesions, respectively. Lesion conspicuity was higher on PET/CT for both malignant and benign pulmonary lesions and in the overall rating for malignant lesions (p < 0.001). There was a difference between PET/CT and PET/MRI in overall evaluation of malignant lesions (p < 0.01) and detection of pulmonary metastases (p < 0.001). Surgical evaluation revealed three malignant lesions missed by both modalities. PET/MRI additionally failed to detect 14 pulmonary metastases and 11 benign lesions. In patients with thyroid cancer and suspected or known dedifferentiation, [ 18 F]FDG PET/MRI was inferior to low-dose [ 18 F]FDG PET/CT for the assessment of pulmonary status. However, for the assessment of cervical status, [ 18 F]FDG PET/MRI was equal to contrast-enhanced neck [ 18 F]FDG PET/CT. Therefore, [ 18 F]FDG PET/MRI combined with a low-dose CT scan of the thorax may provide an imaging solution when high-quality imaging is needed and high-energy CT is undesirable or the use of a contrast agent is contraindicated. (orig.)

Serial MRI and MRS studies with unusual findings in Rasmussen's encephalitis

International Nuclear Information System (INIS)

Tuerkdogan-Soezueer, D.; Oezek, M.M.; Pamir, M.N.; Sav, A.; Dincer, A.

2000-01-01

Rasmussen's syndrome is characterized by intractable seizures and progressive neuropsychiatric deterioration secondary to unilateral cortical inflammation and tissue destruction. Diagnosis of Rasmussen's syndrome in the early phase depends mainly on the clinical features. Neuroimaging and histopathologic examinations may not be specific during this period. We report a case of Rasmussen's syndrome followed by serial MRI and magnetic resonance spectroscopy (MRS) studies over a 3- to 16-month period. A healthy 6-year-old boy presented with focal motor seizures. An MRI study demonstrated prominent enlargement and T2 hyperintensity of the left mesial temporal lobe and perisylvian region. This early finding evolved to volume loss and later progressive atrophy of the ipsilateral hemisphere when epilepsia partialis continua occurred. Being aware of those early MRI features in a patient with increasing frequency of focal motor seizures should suggest Rasmussen's syndrome. In addition, we found prominently increased myoinositol concentration in atrophic cortex which might reflect increased gliosis in the late period of the disease. (orig.)

Regression and statistical shape model based substitute CT generation for MRI alone external beam radiation therapy from standard clinical MRI sequences

Science.gov (United States)

Ghose, Soumya; Greer, Peter B.; Sun, Jidi; Pichler, Peter; Rivest-Henault, David; Mitra, Jhimli; Richardson, Haylea; Wratten, Chris; Martin, Jarad; Arm, Jameen; Best, Leah; Dowling, Jason A.

2017-11-01

In MR only radiation therapy planning, generation of the tissue specific HU map directly from the MRI would eliminate the need of CT image acquisition and may improve radiation therapy planning. The aim of this work is to generate and validate substitute CT (sCT) scans generated from standard T2 weighted MR pelvic scans in prostate radiation therapy dose planning. A Siemens Skyra 3T MRI scanner with laser bridge, flat couch and pelvic coil mounts was used to scan 39 patients scheduled for external beam radiation therapy for localized prostate cancer. For sCT generation a whole pelvis MRI (1.6 mm 3D isotropic T2w SPACE sequence) was acquired. Patients received a routine planning CT scan. Co-registered whole pelvis CT and T2w MRI pairs were used as training images. Advanced tissue specific non-linear regression models to predict HU for the fat, muscle, bladder and air were created from co-registered CT-MRI image pairs. On a test case T2w MRI, the bones and bladder were automatically segmented using a novel statistical shape and appearance model, while other soft tissues were separated using an Expectation-Maximization based clustering model. The CT bone in the training database that was most ‘similar’ to the segmented bone was then transformed with deformable registration to create the sCT component of the test case T2w MRI bone tissue. Predictions for the bone, air and soft tissue from the separate regression models were successively combined to generate a whole pelvis sCT. The change in monitor units between the sCT-based plans relative to the gold standard CT plan for the same IMRT dose plan was found to be 0.3%+/-0.9% (mean  ±  standard deviation) for 39 patients. The 3D Gamma pass rate was 99.8+/-0.00 (2 mm/2%). The novel hybrid model is computationally efficient, generating an sCT in 20 min from standard T2w images for prostate cancer radiation therapy dose planning and DRR generation.

Serial CT scans of cerebral hypoxia due to prolonged status epilepticus

Energy Technology Data Exchange (ETDEWEB)

Saiwai, Shigeo; Matsumura, Yasumasa; Tamaoka, Koichi; Fukuda, Teruo; Miyamoto, Takeshi (Kobe Central Municipal Hospital, Kobe (Japan))

1983-04-01

Serial computed tomography (CT) scans of 5 infants with status epilepticus were reviewed. Four out of the 5 infants fortunately had CT scans before status epilepticus because of a convulsion. There was a diffuse and mild low density in the hemisphere, with small ventricles and tight sulci (brain swelling) at 1 to 2 days after ictus. Thereafter, a diffuse low density became apparent except for the cerebellum, the brain stem, the thalamus, and the basal ganglia. Two to 4 weeks after ictus, a localized, mottled low density was demonstrated on the cerebral mantle and atrophic changes became progressively clear. In 3 cases, no abnormal enhancement was elicited on contrast CT scans performed between 5 to 16 days after status epilepticus. We discussed the possible pathophysiological aspects of the brain damage due to ''prolonged status epilepticus.''

Serial CT scans of cerebral hypoxia due to prolonged status epilepticus

International Nuclear Information System (INIS)

Saiwai, Shigeo; Matsumura, Yasumasa; Tamaoka, Koichi; Fukuda, Teruo; Miyamoto, Takeshi

1983-01-01

Serial computed tomography (CT) scans of 5 infants with status epilepticus were reviewed. Four out of the 5 infants fortunately had CT scans before status epilepticus because of a convulsion. There was a diffuse and mild low density in the hemisphere, with small ventricles and tight sulci (brain swelling) at 1 to 2 days after ictus. Thereafter, a diffuse low density became apparent except for the cerebellum, the brain stem, the thalamus, and the basal ganglia. Two to 4 weeks after ictus, a localized, mottled low density was demonstrated on the cerebral mantle and atrophic changes became progressively clear. In 3 cases, no abnormal enhancement was elicited on contrast CT scans performed between 5 to 16 days after status epilepticus. We discussed the possible pathophysiological aspects of the brain damage due to ''prolonged status epilepticus.'' (author)

Enhancement pattern of small hepatic hemangioma: findings on multiphase spiral CT and dynamic MRI

International Nuclear Information System (INIS)

Choi, Byung In; Lee, Seung Koo; Kim, Myeong Jin; Chung, Jae Joon; Yoo, Hyung Sik; Lee, Jong Tae

1999-01-01

To compare the enhancement characteristics of small hemangiomas seen on multiphase spiral CT and dynamic MR imaging. Thirteen patients with 20 hepatic hemangiomas less than 25mm in diameter underwent both multiphase spiral CT and dynamic MR imaging. All lesions were assigned to one of three classified into 3 categories according to the enhancement pattern seen on multiphase spiral CT : typical delayed pooling, atypical early enhancement, or continuous low attenuation. The enhancement patterns seen on spiral CT and on dynamic MRI were correlated. On CT scans, ten lesions (50%) showed delayed pooling. Six (30%) showed early arterial enhancement and four (20%) showed continuous low attenuation. On delayed-phase MRI, all lesions showed delayed high signal intensity compared to adjacent liver parenchyma. Four of six lesions with early enhancement on CT showed peripheral globular enhancement on early arterial-phase MRI. On multiphase spiral CT scans, small hemangiomas can show variable atypical enhancement features. In this situation, contrast-enhanced dynamic MRI is helpful for the diagnosis of hemangiomas

Serial changes of humor comprehension for four-frame comic Manga: an fMRI study.

Science.gov (United States)

Osaka, Mariko; Yaoi, Ken; Minamoto, Takehiro; Osaka, Naoyuki

2014-07-25

Serial changes of humor comprehension evoked by a well organized four-frame comic Manga were investigated by fMRI in each step of humor comprehension. The neural substrates underlying the amusing effects in response to funny and mixed order manga were compared. In accordance with the time course of the four frames, fMRI activations changed serially. Beginning with the second frame (development scene), activation of the temporo-parietal junction (TPJ) was observed, followed by activations in the temporal and frontal areas during viewing of the third frame (turn scene). For the fourth frame (punch line), strong increased activations were confirmed in the medial prefrontal cortex (MPFC) and cerebellum. Interestingly, distinguishable activation differences in the cerebellum between funny and non-funny conditions were also found for the fourth frame. These findings suggest that humor comprehension evokes activation that initiates in the TPJ and expands to the MPFC and cerebellum at the convergence level.

Comparison of air space measurement imaged by CT, small-animal CT, and hyperpolarized Xe MRI

Science.gov (United States)

Madani, Aniseh; White, Steven; Santyr, Giles; Cunningham, Ian

2005-04-01

Lung disease is the third leading cause of death in the western world. Lung air volume measurements are thought to be early indicators of lung disease and markers in pharmaceutical research. The purpose of this work is to develop a lung phantom for assessing and comparing the quantitative accuracy of hyperpolarized xenon 129 magnetic resonance imaging (HP 129Xe MRI), conventional computed tomography (HRCT), and highresolution small-animal CT (μCT) in measuring lung gas volumes. We developed a lung phantom consisting of solid cellulose acetate spheres (1, 2, 3, 4 and 5 mm diameter) uniformly packed in circulated air or HP 129Xe gas. Air volume is estimated based on simple thresholding algorithm. Truth is calculated from the sphere diameters and validated using μCT. While this phantom is not anthropomorphic, it enables us to directly measure air space volume and compare these imaging methods as a function of sphere diameter for the first time. HP 129Xe MRI requires partial volume analysis to distinguish regions with and without 129Xe gas and results are within %5 of truth but settling of the heavy 129Xe gas complicates this analysis. Conventional CT demonstrated partial-volume artifacts for the 1mm spheres. μCT gives the most accurate air-volume results. Conventional CT and HP 129Xe MRI give similar results although non-uniform densities of 129Xe require more sophisticated algorithms than simple thresholding. The threshold required to give the true air volume in both HRCT and μCT, varies with sphere diameters calling into question the validity of thresholding method.

Cranial CT and MRI in diseases with DNA repair defects

International Nuclear Information System (INIS)

Demaerel, P.; Kendall, B.E.; Kingsley, D.

1992-01-01

The CT and MRI appearances of 5 patients with Cockayne's syndrome, 5 with ataxia telangiectasia and 1 with Fanconi's anaemia are reported. These conditions, together with Bloom's syndrome and xeroderma pigmentosum are regarded as disorders of DNA repair. Characteristic CT and MRI features of Cockayne's syndrome include generalised atrophy, calcification in basal ganglia and dentate nuclei and white matter low density. Neuroradiological findings in the other DNA repair disorders are nonspecific. (orig.)

Quantitative Rapid Assessment of Leukoaraiosis in CT : Comparison to Gold Standard MRI.

Science.gov (United States)

Hanning, Uta; Sporns, Peter Bernhard; Schmidt, Rene; Niederstadt, Thomas; Minnerup, Jens; Bier, Georg; Knecht, Stefan; Kemmling, André

2017-10-20

The severity of white matter lesions (WML) is a risk factor of hemorrhage and predictor of clinical outcome after ischemic stroke; however, in contrast to magnetic resonance imaging (MRI) reliable quantification for this surrogate marker is limited for computed tomography (CT), the leading stroke imaging technique. We aimed to present and evaluate a CT-based automated rater-independent method for quantification of microangiopathic white matter changes. Patients with suspected minor stroke (National Institutes of Health Stroke scale, NIHSS < 4) were screened for the analysis of non-contrast computerized tomography (NCCT) at admission and compared to follow-up MRI. The MRI-based WML volume and visual Fazekas scores were assessed as the gold standard reference. We employed a recently published probabilistic brain segmentation algorithm for CT images to determine the tissue-specific density of WM space. All voxel-wise densities were quantified in WM space and weighted according to partial probabilistic WM content. The resulting mean weighted density of WM space in NCCT, the surrogate of WML, was correlated with reference to MRI-based WML parameters. The process of CT-based tissue-specific segmentation was reliable in 79 cases with varying severity of microangiopathy. Voxel-wise weighted density within WM spaces showed a noticeable correlation (r = -0.65) with MRI-based WML volume. Particularly in patients with moderate or severe lesion load according to the visual Fazekas score the algorithm provided reliable prediction of MRI-based WML volume. Automated observer-independent quantification of voxel-wise WM density in CT significantly correlates with microangiopathic WM disease in gold standard MRI. This rapid surrogate of white matter lesion load in CT may support objective WML assessment and therapeutic decision-making during acute stroke triage.

Imaging with {sup 124}I in differentiated thyroid carcinoma: is PET/MRI superior to PET/CT?

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Binse, I.; Poeppel, T.D.; Ruhlmann, M.; Gomez, B.; Bockisch, A.; Rosenbaum-Krumme, S.J. [University of Duisburg-Essen, Medical Faculty, Department of Nuclear Medicine, Essen (Germany); Umutlu, L. [University of Duisburg-Essen, Medical Faculty, Department of Radiology, Essen (Germany)

2016-06-15

The aim of this study was to compare integrated PET/CT and PET/MRI for their usefulness in detecting and categorizing cervical iodine-positive lesions in patients with differentiated thyroid cancer using {sup 124}I as tracer. The study group comprised 65 patients at high risk of iodine-positive metastasis who underwent PET/CT (low-dose CT scan, PET acquisition time 2 min; PET/CT{sub 2}) followed by PET/MRI of the neck 24 h after {sup 124}I administration. PET images from both modalities were analysed for the numbers of tracer-positive lesions. Two different acquisition times were used for the comparisons, one matching the PET/CT{sub 2} acquisition time (2 min, PET/MRI{sub 2}) and the other covering the whole MRI scan time (30 min, PET/MRI{sub 30}). Iodine-positive lesions were categorized as metastasis, thyroid remnant or inconclusive according to their location on the PET/CT images. Morphological information provided by MRI was considered for evaluation of lesions on PET/MRI and for volume information. PET/MRI{sub 2} detected significantly more iodine-positive metastases and thyroid remnants than PET/CT{sub 2} (72 vs. 60, p = 0.002, and 100 vs. 80, p = 0.001, respectively), but the numbers of patients with at least one tumour lesion identified were not significantly different (21/65 vs. 17/65 patients). PET/MRI{sub 30} tended to detect more PET-positive metastases than PET/MRI{sub 2} (88 vs. 72), but the difference was not significant (p = 0.07). Of 21 lesions classified as inconclusive on PET/CT, 5 were assigned to metastasis or thyroid remnant when evaluated by PET/MRI. Volume information was available in 34 % of iodine-positive metastases and 2 % of thyroid remnants on PET/MRI. PET/MRI of the neck was found to be superior to PET/CT in detecting iodine-positive lesions. This was attributed to the higher sensitivity of the PET component, Although helpful in some cases, we found no substantial advantage of PET/MRI over PET/CT in categorizing iodine

MRI, CT and TRUS imaging of seminal vesicle metastasis

International Nuclear Information System (INIS)

Larsson, P.; Blomqvist, L.; Norming, U.

1997-01-01

We present a case of a testicular germ-cell metastasis in the seminal vesicle. Diagnostic imaging with transrectal ultrasonography (TRUS), CT, and MRI was performed. This case emphasizes the role of MRI in the evaluation of patients with pathology in the pelvic region. (orig.)

Albendazole treatment of cerebral hydatid disease: evaluation of results with CT and MRI

International Nuclear Information System (INIS)

Kalaitzoglou, I.; Drevelengas, A.; Petridis, A.; Palladas, P.

1998-01-01

We report a case of cerebral hydatid disease demonstrated by CT and MRI, treated with albendazole. Follow-up showed complete dissapearance of the cysts with residual focal calcification on CT and presumed gliosis on MRI. (orig.)

Neuroradiological findings in primary progressive aphasia: CT, MRI and cerebral perfusion SPECT

International Nuclear Information System (INIS)

Sinnatamby, R.; Antoun, N.A.; Freer, C.E.L.; Miles, K.A.; Hodges, J.R.

1996-01-01

Primary progressive aphasia (PPA) is defined as progressive decline in language for 2 or more years with preservation of activities of daily living and general cognitive functions. Whereas the clinical features of this syndrome have been well documented, the neuroradiological findings have not been studied systematically. We studied 13 patients with PPA retrospectively: 10 underwent CT, 12 MRI and 12 cerebral perfusion studies using 99m Tc-HMPAO SPECT. CT and MR images were scored for focal atrophy by two independent assessors. Initial qualitative assessment of SPECT images was confirmed by quantitative analysis. CY was normal in 5 patients. Focal atrophy, affecting predominantly the left temporal lobe, was seen in 4 of 10 patients on CT, and 10 of 12 on MRI. Atrophy was localised primarily to the superior and middle temporal gyri on MRI. All 12 patients who underwent SPECT had unilateral temporal lobe perfusion defects, in 2 patients of whom MRI was normal. CT is relatively insensitive to focal abnormalities in PPA; MRI and SPECT are the imaging modalities of choice. MRI allows accurate, specific localisation of atrophy with the temporal neocortex. SPECT may reveal a functional decrease in cerebral perfusion prior to establishment of structural change. (orig.)

Neuroradiological findings in primary progressive aphasia: CT, MRI and cerebral perfusion SPECT

Energy Technology Data Exchange (ETDEWEB)

Sinnatamby, R. [Dept. of Radiology, Addenbrooke`s Hospital NHS Trust, Cambridge (United Kingdom); Antoun, N.A. [Dept. of Radiology, Addenbrooke`s Hospital NHS Trust, Cambridge (United Kingdom); Freer, C.E.L. [Dept. of Radiology, Addenbrooke`s Hospital NHS Trust, Cambridge (United Kingdom); Miles, K.A. [Dept. of Nuclear Medicine, Addenbrooke`s Hospital NHS Trust, Cambridge (United Kingdom); Hodges, J.R. [Dept. of Neurology, Addenbrooke`s Hospital NHS Trust, Cambridge (United Kingdom)

1996-04-01

Primary progressive aphasia (PPA) is defined as progressive decline in language for 2 or more years with preservation of activities of daily living and general cognitive functions. Whereas the clinical features of this syndrome have been well documented, the neuroradiological findings have not been studied systematically. We studied 13 patients with PPA retrospectively: 10 underwent CT, 12 MRI and 12 cerebral perfusion studies using {sup 99m}Tc-HMPAO SPECT. CT and MR images were scored for focal atrophy by two independent assessors. Initial qualitative assessment of SPECT images was confirmed by quantitative analysis. CY was normal in 5 patients. Focal atrophy, affecting predominantly the left temporal lobe, was seen in 4 of 10 patients on CT, and 10 of 12 on MRI. Atrophy was localised primarily to the superior and middle temporal gyri on MRI. All 12 patients who underwent SPECT had unilateral temporal lobe perfusion defects, in 2 patients of whom MRI was normal. CT is relatively insensitive to focal abnormalities in PPA; MRI and SPECT are the imaging modalities of choice. MRI allows accurate, specific localisation of atrophy with the temporal neocortex. SPECT may reveal a functional decrease in cerebral perfusion prior to establishment of structural change. (orig.)

Age determination of subdural hematomas with CT and MRI: a systematic review

NARCIS (Netherlands)

Sieswerda-Hoogendoorn, Tessa; Postema, Floor A. M.; Verbaan, Dagmar; Majoie, Charles B.; van Rijn, Rick R.

2014-01-01

To systematically review the literature on dating subdural hematomas (SDHs) on CT and MRI scans. We performed a systematic review in MEDLINE, EMBASE and Cochrane to search for articles that described the appearance of SDHs on CT or MRI in relation to time between trauma and scanning. Two researchers

Semi-automatic delineation using weighted CT-MRI registered images for radiotherapy of nasopharyngeal cancer

Energy Technology Data Exchange (ETDEWEB)

Fitton, I. [European Georges Pompidou Hospital, Department of Radiology, 20 rue Leblanc, 75015, Paris (France); Cornelissen, S. A. P. [Image Sciences Institute, UMC, Department of Radiology, P.O. Box 85500, 3508 GA Utrecht (Netherlands); Duppen, J. C.; Rasch, C. R. N.; Herk, M. van [The Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Department of Radiotherapy, Plesmanlaan 121, 1066 CX Amsterdam (Netherlands); Steenbakkers, R. J. H. M. [University Medical Center Groningen, Department of Radiation Oncology, Hanzeplein 1, 9713 GZ Groningen (Netherlands); Peeters, S. T. H. [UZ Gasthuisberg, Herestraat 49, 3000 Leuven, Belgique (Belgium); Hoebers, F. J. P. [Maastricht University Medical Center, Department of Radiation Oncology (MAASTRO clinic), GROW School for Oncology and Development Biology Maastricht, 6229 ET Maastricht (Netherlands); Kaanders, J. H. A. M. [UMC St-Radboud, Department of Radiotherapy, Geert Grooteplein 32, 6525 GA Nijmegen (Netherlands); Nowak, P. J. C. M. [ERASMUS University Medical Center, Department of Radiation Oncology,Groene Hilledijk 301, 3075 EA Rotterdam (Netherlands)

2011-08-15

Purpose: To develop a delineation tool that refines physician-drawn contours of the gross tumor volume (GTV) in nasopharynx cancer, using combined pixel value information from x-ray computed tomography (CT) and magnetic resonance imaging (MRI) during delineation. Methods: Operator-guided delineation assisted by a so-called ''snake'' algorithm was applied on weighted CT-MRI registered images. The physician delineates a rough tumor contour that is continuously adjusted by the snake algorithm using the underlying image characteristics. The algorithm was evaluated on five nasopharyngeal cancer patients. Different linear weightings CT and MRI were tested as input for the snake algorithm and compared according to contrast and tumor to noise ratio (TNR). The semi-automatic delineation was compared with manual contouring by seven experienced radiation oncologists. Results: A good compromise for TNR and contrast was obtained by weighing CT twice as strong as MRI. The new algorithm did not notably reduce interobserver variability, it did however, reduce the average delineation time by 6 min per case. Conclusions: The authors developed a user-driven tool for delineation and correction based a snake algorithm and registered weighted CT image and MRI. The algorithm adds morphological information from CT during the delineation on MRI and accelerates the delineation task.

Ultrasound, CT and MRI of ruptured and disseminated hydatid cysts

Energy Technology Data Exchange (ETDEWEB)

Sinner, W.N. von (King Faisal Specialist Hospital and Research Centre, Riyadh (Saudi Arabia). Department of Radiology)

Three cases of echinococcus granulosus with rupture of hydatid cysts and widespread abdominal, pelvic of pleural dissemination are described. Ultrasound (US), computed tomography (CT) and magnetic resonance imaging (MRI) allowed recognition of ruptured hydatid cysts. This assisted to come to an appropriate therapy and exclusion or confirmation of hydatid cysts elsewhere in the body. Ultrasound, CT and MRI are also important for follow-up, evaluation of therapeutic response and/or early diagnosis of recurrence. (author). 22 refs.; 3 figs.

Ultrasound, CT and MRI of ruptured and disseminated hydatid cysts

International Nuclear Information System (INIS)

Sinner, W.N. von

1990-01-01

Three cases of echinococcus granulosus with rupture of hydatid cysts and widespread abdominal, pelvic of pleural dissemination are described. Ultrasound (US), computed tomography (CT) and magnetic resonance imaging (MRI) allowed recognition of ruptured hydatid cysts. This assisted to come to an appropriate therapy and exclusion or confirmation of hydatid cysts elsewhere in the body. Ultrasound, CT and MRI are also important for follow-up, evaluation of therapeutic response and/or early diagnosis of recurrence. (author). 22 refs.; 3 figs

Alveolar Echinococcosis of the Liver: Correlative Color Doppler US, CT, and MRI Study

International Nuclear Information System (INIS)

Cokun, A.; Oeztuerk, M.; Karahan, O.I.; Erdogan, N.; Ikin, S.; Guelec, M.

2004-01-01

Purpose: To determine and compare the imaging features of hepatic alveolar Echinococcosis using color Doppler US, CT, and MRI. Material and Methods: Abdominal CT and MRI with and without contrast agents and color Doppler US were performed on seven patients with hepatic alveolar Echinococcosis. The lesions were evaluated for location, features of echogenicity, intensity and density, calcification, and vascular, hilar, and perihepatic involvement. The diagnosis was confirmed histopathologically in all patients. Results: Six patients had solitary lesions, and one displayed multiple lesions. The lesions were generally seen as heterogeneous and hyper- or hypoechoic when imaged with color Doppler US, hypodense with CT, and hypointense with MRI, in comparison with the liver parenchyma. Calcification, central necrosis, and small peripheral cysts were observed in six, seven, and four patients, respectively. Vascular flow or contrast enhancement was not observed in any of the cases. A look at the respective advantages of each method reveals that calcification was best rendered visible via CT, small peripheral cysts with T2-weighted MRI, central necrosis with CT and MRI, and perihepatic invasion with multiplanar MRI. Vascular involvement was revealed by all methods. Conclusion: Color Doppler US, CT, and MR imaging function extremely well as complementary methods in the diagnosis of HAE. Color Doppler US should be performed in these patients owing to its ability to efficiently detect the disease. Knowledge of imaging characteristics makes it possible to radiologically ascertain an early diagnosis

Serial CT scans and Menkes' kinky hair disease

Energy Technology Data Exchange (ETDEWEB)

Nakada, Eizo; Kameyama, Junji; Yoshimitsu, Hajime; Mori, Mikio; Tanaka, Mutsuo; Yoshimitsu, Kazunori.

1988-02-01

Menkes' kinky hair disease is a sex-linked recessive disorder of copper metabolism, characterized by progressive psychomotor deterioration, seizures, and peculiar hair structure. We examined serial CT scans of patients with this disease. A 2,210-g male infant was delivered after an uneventful gestation of 36 weeks. His one-minute Apgar score was 9. His uncle had died at 1 year of age. His first cousin was also diagnosed as having Menkes' kinky hair disease when our patient was 2 years old. Shortly after birth he had mild respiratory distress. At 5 days of age, he developed setting-sun signs. The first CT scan, at 10 days of age, revealed mild posterior fossa hemorrhages. At 3 months of age, myoclonic seizures began, and the CT scan revealed subdural effusion and mild brain atrophy. The seizures were controllable by using phenobarbital, valproic acid, and nitrazepam. He did not follow light or a fixate, but the fundi were normal. He was diffusely hypotonic. At 9 months of age, the seizures became uncontrollable. The CT scans at 15 and 31 months of age showed subdural hemorrhage and/or brain atrophy. At 15 months of age, the serum copper level was 42 ..mu.. g/dl, while the serum ceruloplasmin level was 3.2 mg/dl. He exhibited severe developmental failure. At 4 years of age, he died.

Comparison of AMI-25 enhanced MRI and helical dynamic CT in the detection of hepatic lesions

International Nuclear Information System (INIS)

Saitou, Kazuhiro; Matsuda, Hiromichi; Fukushima, Hiroaki; Kanzaki, Hiroshi; Hirose, Takashi; Karizaki, Dai; Abe, Kimihiko; Amino, Saburou

1994-01-01

We performed AMI-25 enhanced MRI and helical dynamic CT in 12 cases of hepatic lesions. Nine of these were hepatocellular carcinomas. Two cases were metastatic liver tumors (the primary lesion was gastric in one and the other was gallbladder cancer). One case was suspected to be adenomatous hyperplasia. Thirty-two lesions were detected in T2-weighted SE images before AMI-25 administration, while 46 lesions were detected in AMI-25 enhanced MRI images. In particular, AMI-25 enhanced MRI was superior to plain MRI in lesions less than 10 mm in size. A total of 48 lesions were detected in helical dynamic CT. Although AMI-25 enhanced MRI almost equaled helical dynamic CT in the detection of liver tumors, helical dynamic CT was slightly superior to AMI-25 enhanced MRI in the detection of subphrenic lesions. It was possible to know the hemodynamics in each hepatic lesion by helical dynamic CT. AMI-25 enhanced MRI was useful to know the inclusion of reticuloendothelial system, and that yielded different diagnoses in adenomatous hyperplasia and well differentiated hepatocellular carcinoma. Helical dynamic CT was useful for qualitative diagnosis. Both AMI-25 enhanced MRI and helical dynamic CT contributed to the detection of liver tumor and qualitative diagnosis. (author)

Coronary imaging techniques with emphasis on CT and MRI

International Nuclear Information System (INIS)

Lederlin, Mathieu; Latrabe, Valerie; Corneloup, Olivier; Cochet, Hubert; Montaudon, Michel; Laurent, Francois; Thambo, Jean-Benoit

2011-01-01

Coronary artery imaging in children is challenging, with high demands both on temporal and spatial resolution due to high heart rates and smaller anatomy. Although invasive conventional coronary angiography remains the benchmark technique, over the past 10 years, CT and MRI have emerged in the field of coronary imaging. The choice of hardware is important. For CT, the minimum requirement is a 64-channel scanner. The temporal resolution of the scanner is most important for optimising image quality and minimising radiation dose. Manufacturers have developed several modes of electrocardiographic (ECG) triggering to facilitate dose reduction. Recent technical advances have opened new possibilities in MRI coronary imaging. As a non-ionising radiation technique, MRI is of great interest in paediatric imaging. It is currently recommended in centres with appropriate expertise for the screening of patients with suspected congenital coronary anomalies. However, MRI is still not feasible in infants. This review describes and discusses the technical requirements and the pros and cons of all three techniques. (orig.)

Semi-automatic analysis of standard uptake values in serial PET/CT studies in patients with lung cancer and lymphoma

Directory of Open Access Journals (Sweden)

Ly John

2012-04-01

Full Text Available Abstract Background Changes in maximum standardised uptake values (SUVmax between serial PET/CT studies are used to determine disease progression or regression in oncologic patients. To measure these changes manually can be time consuming in a clinical routine. A semi-automatic method for calculation of SUVmax in serial PET/CT studies was developed and compared to a conventional manual method. The semi-automatic method first aligns the serial PET/CT studies based on the CT images. Thereafter, the reader selects an abnormal lesion in one of the PET studies. After this manual step, the program automatically detects the corresponding lesion in the other PET study, segments the two lesions and calculates the SUVmax in both studies as well as the difference between the SUVmax values. The results of the semi-automatic analysis were compared to that of a manual SUVmax analysis using a Philips PET/CT workstation. Three readers did the SUVmax readings in both methods. Sixteen patients with lung cancer or lymphoma who had undergone two PET/CT studies were included. There were a total of 26 lesions. Results Linear regression analysis of changes in SUVmax show that intercepts and slopes are close to the line of identity for all readers (reader 1: intercept = 1.02, R2 = 0.96; reader 2: intercept = 0.97, R2 = 0.98; reader 3: intercept = 0.99, R2 = 0.98. Manual and semi-automatic method agreed in all cases whether SUVmax had increased or decreased between the serial studies. The average time to measure SUVmax changes in two serial PET/CT examinations was four to five times longer for the manual method compared to the semi-automatic method for all readers (reader 1: 53.7 vs. 10.5 s; reader 2: 27.3 vs. 6.9 s; reader 3: 47.5 vs. 9.5 s; p Conclusions Good agreement was shown in assessment of SUVmax changes between manual and semi-automatic method. The semi-automatic analysis was four to five times faster to perform than the manual analysis. These findings show the

Simulation of spatiotemporal CT data sets using a 4D MRI-based lung motion model.

Science.gov (United States)

Marx, Mirko; Ehrhardt, Jan; Werner, René; Schlemmer, Heinz-Peter; Handels, Heinz

2014-05-01

Four-dimensional CT imaging is widely used to account for motion-related effects during radiotherapy planning of lung cancer patients. However, 4D CT often contains motion artifacts, cannot be used to measure motion variability, and leads to higher dose exposure. In this article, we propose using 4D MRI to acquire motion information for the radiotherapy planning process. From the 4D MRI images, we derive a time-continuous model of the average patient-specific respiratory motion, which is then applied to simulate 4D CT data based on a static 3D CT. The idea of the motion model is to represent the average lung motion over a respiratory cycle by cyclic B-spline curves. The model generation consists of motion field estimation in the 4D MRI data by nonlinear registration, assigning respiratory phases to the motion fields, and applying a B-spline approximation on a voxel-by-voxel basis to describe the average voxel motion over a breathing cycle. To simulate a patient-specific 4D CT based on a static CT of the patient, a multi-modal registration strategy is introduced to transfer the motion model from MRI to the static CT coordinates. Differences between model-based estimated and measured motion vectors are on average 1.39 mm for amplitude-based binning of the 4D MRI data of three patients. In addition, the MRI-to-CT registration strategy is shown to be suitable for the model transformation. The application of our 4D MRI-based motion model for simulating 4D CT images provides advantages over standard 4D CT (less motion artifacts, radiation-free). This makes it interesting for radiotherapy planning.

TH-C-BRD-06: A Novel MRI Based CT Artifact Correction Method for Improving Proton Range Calculation in the Presence of Severe CT Artifacts

International Nuclear Information System (INIS)

Park, P; Schreibmann, E; Fox, T; Roper, J; Elder, E; Tejani, M; Crocker, I; Curran, W; Dhabaan, A

2014-01-01

Purpose: Severe CT artifacts can impair our ability to accurately calculate proton range thereby resulting in a clinically unacceptable treatment plan. In this work, we investigated a novel CT artifact correction method based on a coregistered MRI and investigated its ability to estimate CT HU and proton range in the presence of severe CT artifacts. Methods: The proposed method corrects corrupted CT data using a coregistered MRI to guide the mapping of CT values from a nearby artifact-free region. First patient MRI and CT images were registered using 3D deformable image registration software based on B-spline and mutual information. The CT slice with severe artifacts was selected as well as a nearby slice free of artifacts (e.g. 1cm away from the artifact). The two sets of paired MRI and CT images at different slice locations were further registered by applying 2D deformable image registration. Based on the artifact free paired MRI and CT images, a comprehensive geospatial analysis was performed to predict the correct CT HU of the CT image with severe artifact. For a proof of concept, a known artifact was introduced that changed the ground truth CT HU value up to 30% and up to 5cm error in proton range. The ability of the proposed method to recover the ground truth was quantified using a selected head and neck case. Results: A significant improvement in image quality was observed visually. Our proof of concept study showed that 90% of area that had 30% errors in CT HU was corrected to 3% of its ground truth value. Furthermore, the maximum proton range error up to 5cm was reduced to 4mm error. Conclusion: MRI based CT artifact correction method can improve CT image quality and proton range calculation for patients with severe CT artifacts

Hepatic sinusoidal obstruction syndrome caused by herbal medicine: CT and MRI features

International Nuclear Information System (INIS)

Zhou, Hua; Lou, Hai Yan; Wang, Yi Xiang J.; Xu, Xiao Jun; Zhang, Min Ming

2014-01-01

To describe the CT and MRI features of hepatic sinusoidal obstruction syndrome (HSOS) caused by herbal medicine Gynura segetum. The CT and MRI features of 16 consecutive Gynura segetum induced HSOS cases (12 men, 4 women) were analyzed. Eight patients had CT; three patients had MRI, and the remaining five patients had both CT and MRI examinations. Based on their clinical presentations and outcomes, the patients were classified into three categories: mild, moderate, and severe. The severity of the disease was also evaluated radiologically based on the abnormal hepatic patchy enhancement in post-contrast CT or MRI images. Ascites, patchy liver enhancement, and main right hepatic vein narrowing or occlusion were present in all 16 cases. Hepatomegaly and gallbladder wall thickening were present in 14 cases (87.5%, 14/16). Periportal high intensity on T2-weighted images was present in 6 cases (75%, 6/8). Normal liver parenchymal enhancement surrounding the main hepatic vein forming a clover-like sign was observed in 4 cases (25%, 4/16). The extent of patchy liver enhancement was statistically associated with clinical severity classification (kappa = 0.565). Ascites, patchy liver enhancement, and the main hepatic veins narrowing were the most frequent signs of herbal medicine induced HSOS. The grade of abnormal patchy liver enhancement was associated with the clinical severity.

Hepatic sinusoidal obstruction syndrome caused by herbal medicine: CT and MRI features

Energy Technology Data Exchange (ETDEWEB)

Zhou, Hua; Lou, Hai Yan [Dept. of Radiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou (China); Wang, Yi Xiang J. [Dept. of Radiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou (China); Xu, Xiao Jun; Zhang, Min Ming [Dept. of Radiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou (China)

2014-04-15

To describe the CT and MRI features of hepatic sinusoidal obstruction syndrome (HSOS) caused by herbal medicine Gynura segetum. The CT and MRI features of 16 consecutive Gynura segetum induced HSOS cases (12 men, 4 women) were analyzed. Eight patients had CT; three patients had MRI, and the remaining five patients had both CT and MRI examinations. Based on their clinical presentations and outcomes, the patients were classified into three categories: mild, moderate, and severe. The severity of the disease was also evaluated radiologically based on the abnormal hepatic patchy enhancement in post-contrast CT or MRI images. Ascites, patchy liver enhancement, and main right hepatic vein narrowing or occlusion were present in all 16 cases. Hepatomegaly and gallbladder wall thickening were present in 14 cases (87.5%, 14/16). Periportal high intensity on T2-weighted images was present in 6 cases (75%, 6/8). Normal liver parenchymal enhancement surrounding the main hepatic vein forming a clover-like sign was observed in 4 cases (25%, 4/16). The extent of patchy liver enhancement was statistically associated with clinical severity classification (kappa = 0.565). Ascites, patchy liver enhancement, and the main hepatic veins narrowing were the most frequent signs of herbal medicine induced HSOS. The grade of abnormal patchy liver enhancement was associated with the clinical severity.

X-ray, CT and MRI findings of synovial tuberculosis in joints

International Nuclear Information System (INIS)

Yu Jinghong; Tao Meili; You Zhuangzhi; Yu Huazhi

2006-01-01

Objective: To analyze the X-ray, CT and MRI findings of synovial tuberculosis, and to evaluate the role of MRI in diagnosing synovial tuberculosis. Methods: Fourteen cases of synovial tuberculosis comfirmed by operation and pathology were retrospectively analyzed and summarized. All patients were examined by MRI and X-ray, and CT scans were performed in 3 cases. Results: X-ray showed joint swelling (8 cases), articular space narrowing (7 cases), marginal joint erosions (4 cases), and periarticular osteoporosis (9 cases). The joint swelling was detected on CT in all 3 cases, and bony erosion and speckled sequestra were seen in 2 cases. MRI in all of patients showed joint swelling and synovial proliferation in different drgees, demonstrated as heterogeneously low signal on T 1 WI and slight high signal (7 cases) and obvious high signal (6 cases) on T 2 WI, and diffuse synovial proliferation was demonstrated as massive and nodular signal in 8 cases. Joint effusion was present in 7 cases as low signal on T 1 WI and high signal on T 2 WI. Osseous erosion lesions were seen in 7 cases, and intra-articular cartilage thinned, partly or mostly disappeared in 11 cases. Periarticular bone marrow edema was found in 7 cases. Conclusion: MRI was superior to X-ray and CT in the diagnosis and differential diagnosis of synovial tuberculosis. (authors)

Albendazole treatment of cerebral hydatid disease: evaluation of results with CT and MRI

Energy Technology Data Exchange (ETDEWEB)

Kalaitzoglou, I.; Drevelengas, A.; Petridis, A.; Palladas, P. [Department of Radiology, ``G. Papanikolaou`` General Hospital, Thessaloniki (Greece)

1998-01-01

We report a case of cerebral hydatid disease demonstrated by CT and MRI, treated with albendazole. Follow-up showed complete dissapearance of the cysts with residual focal calcification on CT and presumed gliosis on MRI. (orig.) With 3 figs., 17 refs.

Prospective evaluation of MRI, 11C-acetate PET/CT and contrast-enhanced CT for staging of bladder cancer

International Nuclear Information System (INIS)

Vargas, H.A.; Akin, O.; Schöder, H.; Olgac, S.; Dalbagni, G.; Hricak, H.; Bochner, B.H.

2012-01-01

Purpose: To prospectively evaluate the diagnostic performance of magnetic resonance imaging (MRI), 11 C-acetate positron emission tomography/computed tomography (PET/CT) and contrast-enhanced CT for bladder cancer staging, using whole-mount pathologic review of radical cystectomy and pelvic lymph node specimens as the reference standard. Materials and methods: The institutional review board approved this prospective study, which was compliant with the Health Insurance Portability and Accountability Act. Written informed consent was obtained from 16 patients with histologically confirmed bladder cancer who underwent MRI, 11 C-acetate PET/CT and contrast-enhanced CT before radical cystectomy and pelvic lymph node dissection. Before imaging 4/16 patients had received intravesical Bacillus Calmette-Guérin treatment, 6 had received systemic chemotherapy, 3 had received both and 3 had received neither. Measures of diagnostic performance including accuracy, sensitivity and specificity were estimated separately for each imaging modality. Results: MRI correctly staged 56% of patients (9/16), overstaged 38% (6/16) and understaged 6% (1/16). CT correctly staged 50% of patients (8/16), overstaged 44% (7/16) and understaged 6% (1/16). In 9 patients, 11 C-acetate PET/CT showed uptake within the bladder wall; the uptake was true-positive in 7 patients and false-positive in 2 patients. Of the remaining 7 patients, 5 had true-negative and 2 had false-negative PET/CT results for cancer in the bladder wall. For all modalities, staging accuracy was reduced in patients with a history of prior intravesical and/or systemic chemotherapy. Conclusion: In staging bladder cancer, MRI, 11 C-acetate PET/CT and CT displayed similar levels of accuracy. For all modalities, a history of intravesical and/or systemic chemotherapy affected staging accuracy.

Usefulness of MRI compared with CT for diagnosis of mesenteric lymphoma in a dog

International Nuclear Information System (INIS)

Yasuda, D.; Fujita, M.; Yasuda, S.; Taniguchi, A.; Miura, H.; Hasegawa, D.; Orima, H.

2004-01-01

We evaluated the usefulness of MRI and compared it with CT for diagnosis of mesenceric lymphoma in a dog. The results in the plain CT. dynamic CT and plain MR (TIWI and t2W1) images suggested that the mass was a large single nodular lesion with abundant blood perfusion. On enhanced MRI(T1WI) , the mass was depicted as a tumor with adhesion to the gut wall, Exploratory laparotomy confirmed the mass was consistent with the findings on enhanced MRI. We think that MRI might be a useful imaging tool for diagnosis of canine mesenteric lymphoma

Usefulness of MRI compared with CT for diagnosis of mesenteric lymphoma in a dog.

Science.gov (United States)

Yasuda, Daiji; Fujita, Michio; Yasuda, Shuichi; Taniguchi, Akiko; Miura, Harumi; Hasegawa, Daisuke; Orima, Hiromitsu

2004-11-01

We evaluated the usefulness of MRI and compared it with CT for diagnosis of mesenteric lymphoma in a dog. The results in the plain CT, dynamic CT and plain MR (T1WI and T2WI) images suggested that the mass was a large single nodular lesion with abundant blood perfusion. On enhanced MRI(T1WI) , the mass was depicted as a tumor with adhesion to the gut wall. Exploratory laparotomy confirmed the mass was consistent with the findings on enhanced MRI. We think that MRI might be a useful imaging tool for diagnosis of canine mesenteric lymphoma.

Cranial CT and MRI in diseases with DNA repair defects

Energy Technology Data Exchange (ETDEWEB)

Demaerel, P.; Kendall, B.E.; Kingsley, D. (Dept. of Neuroradiology, Hospital for Sick Children, London (United Kingdom))

1992-04-01

The CT and MRI appearances of 5 patients with Cockayne's syndrome, 5 with ataxia telangiectasia and 1 with Fanconi's anaemia are reported. These conditions, together with Bloom's syndrome and xeroderma pigmentosum are regarded as disorders of DNA repair. Characteristic CT and MRI features of Cockayne's syndrome include generalised atrophy, calcification in basal ganglia and dentate nuclei and white matter low density. Neuroradiological findings in the other DNA repair disorders are nonspecific. (orig.).

18F-Fluorodeoxyglucose PET/CT and dynamic contrast-enhanced MRI as imaging biomarkers in malignant pleural mesothelioma.

Science.gov (United States)

Hall, David O; Hooper, Clare E; Searle, Julie; Darby, Michael; White, Paul; Harvey, John E; Braybrooke, Jeremy P; Maskell, Nick A; Masani, Vidan; Lyburn, Iain D

2018-02-01

The purpose of this study was to compare the use of fluorine-18-fluorodeoxyglucose (F-FDG) PET with computed tomography (CT) and dynamic contrast-enhanced (DCE) MRI to predict prognosis and monitor treatment in malignant pleural mesothelioma. F-FDG PET/CT and DCE-MRI studies carried out as part of the South West Area Mesothelioma Pemetrexed trial were used. F-FDG PET/CT and DCE-MRI studies were carried out before treatment, and after two cycles of chemotherapy, on patients treated with pemetrexed and cisplatin. A total of 73 patients were recruited, of whom 65 had PET/CT and DCE-MRI scans. Baseline measurements from F-FDG PET/CT (maximum standardized uptake value, metabolic tumour volume and total lesion glycolysis) and DCE-MRI (integrated area under the first 90s of the curve and washout slope) were compared with overall survival (OS) using Kaplan-Meier and Cox regression analyses, and changes in imaging measurements were compared with disease progression. PET/CT and DCE-MRI measurements were not correlated with each other. Maximum standardized uptake value, metabolic tumour volume and total lesion glycolysis were significantly related to OS with Cox regression analysis and Kaplan-Meir analysis, and DCE-MRI washout curve shape was significantly related to OS. DCE-MRI curve shape can be combined with F-FDG PET/CT to give additional prognostic information. Changes in measurements were not related to progression-free survival. F-FDG PET/CT and DCE-MRI give prognostic information in malignant pleural mesothelioma. Neither PET/CT nor DCE-MRI is useful for monitoring disease progression.

Semicircular canal dehiscence: comparison of T2-weighted turbo spin-echo MRI and CT

Energy Technology Data Exchange (ETDEWEB)

Krombach, G.A.; Schmitz-Rode, T.; Haage, P.; Guenther, R.W. [Department of Diagnostic Radiology, University of Technology, Pauwelstrasse 30, 52057, Aachen (Germany); DiMartino, E. [Department of Otorhinolaryngology, University of Technology, Pauwelstrasse 30, 52057, Aachen (Germany); Prescher, A. [Department of Anatomy, University of Technology, Pauwelstrasse 30, 52057, Aachen (Germany); Kinzel, S. [Department of Experimental Veterinary Medicine, University of Technology, Pauwelstrasse 30, 52057, Aachen (Germany)

2004-04-01

We assessed the value of MRI for delineation of dehiscence of the superior or posterior semicircular canal, as compared with CT, the current standard study for this entity. We reviewed heavily T2-weighted fast spin-echo images and high-resolution CT of the temporal bones of 185 patients independently semicircular canal dehiscence and its extent. In 30 patients (19 men, 11 women) we identified dehiscence of the bone over the superior and/or posterior semicircular canal on MRI. In 27 of these cases CT also showed circumscribed bone defects. In one patient dehiscence of the superior semicircular canal was initially overlooked on MRI, but seen on CT. MRI imaging thus had a sensitivity of 96% and specificity of 98%. Knowledge of the appearances of this entity on MRI may contribute to early diagnosis in patients with vertigo due to semicircular canal dehiscence. (orig.)

Semicircular canal dehiscence: comparison of T2-weighted turbo spin-echo MRI and CT

International Nuclear Information System (INIS)

Krombach, G.A.; Schmitz-Rode, T.; Haage, P.; Guenther, R.W.; DiMartino, E.; Prescher, A.; Kinzel, S.

2004-01-01

We assessed the value of MRI for delineation of dehiscence of the superior or posterior semicircular canal, as compared with CT, the current standard study for this entity. We reviewed heavily T2-weighted fast spin-echo images and high-resolution CT of the temporal bones of 185 patients independently semicircular canal dehiscence and its extent. In 30 patients (19 men, 11 women) we identified dehiscence of the bone over the superior and/or posterior semicircular canal on MRI. In 27 of these cases CT also showed circumscribed bone defects. In one patient dehiscence of the superior semicircular canal was initially overlooked on MRI, but seen on CT. MRI imaging thus had a sensitivity of 96% and specificity of 98%. Knowledge of the appearances of this entity on MRI may contribute to early diagnosis in patients with vertigo due to semicircular canal dehiscence. (orig.)

Atlas-guided generation of pseudo-CT images for MRI-only and hybrid PET-MRI-guided radiotherapy treatment planning

DEFF Research Database (Denmark)

Arabi, H.; Koutsouvelis, N.; Rouzaud, M.

2016-01-01

Magnetic resonance imaging (MRI)-guided attenuation correction (AC) of positron emission tomography (PET) data and/or radiation therapy (RT) treatment planning is challenged by the lack of a direct link between MRI voxel intensities and electron density. Therefore, even if this is not a trivial t......-CT images from conventional Dixon MRI sequences with improved bone extraction accuracy. The approach is promising for potential use in PET AC and MRI-only or hybrid PET/MRI-guided RT treatment planning. © 2016 Institute of Physics and Engineering in Medicine.......Magnetic resonance imaging (MRI)-guided attenuation correction (AC) of positron emission tomography (PET) data and/or radiation therapy (RT) treatment planning is challenged by the lack of a direct link between MRI voxel intensities and electron density. Therefore, even if this is not a trivial...... the conventional MRI segmentation technique and a recently proposed multi-atlas approach. The clinical studies consisted of pelvic CT, PET and MRI scans of 12 patients with loco-regionally advanced rectal disease. In the first step, bone segmentation of the target image is optimized through local weighted atlas...

A Bone Metastasis Nude Mouse Model Created by Ultrasound Guided Intracardiac Injection of Breast Cancer Cells: the Micro-CT, MRI and Bioluminescence Imaging Analysis

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Park, Young Jin; Song, Eun Hye; Kim, Seol Hwa; Song, Ho Taek; Suh, Jin Suck [Yonsei University College of Medicine, Seoul (Korea, Republic of); Choi, Sang Hyun [Korean Minjok Leadership Academy, Heongsung (Korea, Republic of)

2011-01-15

The purpose of this study was to develop a nude mouse model of bone metastasis by performing intracardiac injection of breast cancer cells under ultrasonography guidance and we wanted to evaluate the development and the distribution of metastasis in vivo using micro-CT, MRI and bioluminescence imaging. Animal experiments were performed in 6-week-old female nude mice. The animals underwent left ventricular injection of 2x105 MDA-MB-231Bo-Luc cells. After injection of the tumor cells, serial bioluminescence imaging was performed for 7 weeks. The findings of micro-CT, MRI and the histology were correlated with the 'hot' lesions seen on the bioluminescence imaging. Metastasis was found in 62.3% of the animals. Two weeks after intracardiac injection, metastasis to the brain, spine and femur was detected with bioluminescence imaging with an increasing intensity by week 7. Micro-CT scan confirmed multiple osteolytic lesions at the femur, spine and skull. MRI and the histology were able to show metastasis in the brain and extraskeletal metastasis around the femur. The intracardiac injection of cancer cells under ultrasonography guidance is a safe and highly reproducible method to produce bone metastasis in nude mice. This bone metastasis nude mouse model will be useful to study the mechanism of bone metastasis and to validate new therapeutics

Characteristic CT and MRI findings of intracranial chondroma

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Duan, Fuhong; Qiu, Shijun; Liu, Zhenyin; Lv, Xiaofei; Feng, Xia; Xiong, Wei; An, Jie; Chen, Jing; Yang, Weicong; Wen, Chuhong [Department of Medical Imaging Center, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong (China)], E-mail: qiushijun006@163.com; Jiang, Jianwei; Chang, Jun [Department of Radiology, The Third Affiliated Hospital of Nantong University, Wuxi, Jiangsu (China)

2012-12-15

Background. Intracranial chondromas are rare benign tumors. To date, few data are available on their neuroradiological features. Purpose. To describe a series of patients with intracranial chondroma and to analyze and discuss the computed tomography (CT) and magnetic resonance imaging (MRI) features that may distinguish chondromas from other intracranial neoplasms. Material and Methods. We retrospectively analyzed clinical and medical imaging data of six patients who had pathologically confirmed intracranial chondromas in our two institutions between July 2006 and September 2011. Both CT and MRI scanning were performed in all six cases. Results. Five tumors were located at the skull base and one originated from the falx. CT images revealed well-demarcated, irregular lobulated and variable density masses with obvious calci?cation (6/6), no or slight enhancement, without peritumoral edema, and frequently accompanied by erosion and destruction of surrounding bone (5/6). Tumor parenchyma appeared heterogeneously hypointense on T1WI, and hyperintense or mixed hyperintense and hypointense on T2WI, while the calcification appeared hypointense on T1WI and T2WI in five cases, demonstrating significant inhomogeneous enhancement on postcontrast MRI, which revealed the typical 'punica granatum seeds' sign. Only one case showed homogeneous low signal intensity on T1WI and high signal intensity on T2WI, and relatively uniform obvious enhancement on postcontrast scans. Conclusion. These characteristic CT and MR findings, combined with the location of the lesions and the history of a long duration of clinical symptoms, may prove helpful in differentiating intracranial chondromas from other more common tumors.

Characteristic CT and MRI findings of intracranial chondroma

International Nuclear Information System (INIS)

Duan, Fuhong; Qiu, Shijun; Liu, Zhenyin; Lv, Xiaofei; Feng, Xia; Xiong, Wei; An, Jie; Chen, Jing; Yang, Weicong; Wen, Chuhong; Jiang, Jianwei; Chang, Jun

2012-01-01

Background. Intracranial chondromas are rare benign tumors. To date, few data are available on their neuroradiological features. Purpose. To describe a series of patients with intracranial chondroma and to analyze and discuss the computed tomography (CT) and magnetic resonance imaging (MRI) features that may distinguish chondromas from other intracranial neoplasms. Material and Methods. We retrospectively analyzed clinical and medical imaging data of six patients who had pathologically confirmed intracranial chondromas in our two institutions between July 2006 and September 2011. Both CT and MRI scanning were performed in all six cases. Results. Five tumors were located at the skull base and one originated from the falx. CT images revealed well-demarcated, irregular lobulated and variable density masses with obvious calci?cation (6/6), no or slight enhancement, without peritumoral edema, and frequently accompanied by erosion and destruction of surrounding bone (5/6). Tumor parenchyma appeared heterogeneously hypointense on T1WI, and hyperintense or mixed hyperintense and hypointense on T2WI, while the calcification appeared hypointense on T1WI and T2WI in five cases, demonstrating significant inhomogeneous enhancement on postcontrast MRI, which revealed the typical 'punica granatum seeds' sign. Only one case showed homogeneous low signal intensity on T1WI and high signal intensity on T2WI, and relatively uniform obvious enhancement on postcontrast scans. Conclusion. These characteristic CT and MR findings, combined with the location of the lesions and the history of a long duration of clinical symptoms, may prove helpful in differentiating intracranial chondromas from other more common tumors

A patch-based pseudo-CT approach for MRI-only radiotherapy in the pelvis

Energy Technology Data Exchange (ETDEWEB)

Andreasen, Daniel, E-mail: dana@dtu.dk [Department of Applied Mathematics and Computer Science, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark and Radiotherapy Research Unit, Department of Oncology, Gentofte and Herlev Hospital, University of Copenhagen, 2730 Herlev (Denmark); Van Leemput, Koen [Department of Applied Mathematics and Computer Science, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark and A.A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129 (United States); Edmund, Jens M. [Radiotherapy Research Unit, Department of Oncology, Gentofte and Herlev Hospital, University of Copenhagen, 2730 Herlev (Denmark)

2016-08-15

Purpose: In radiotherapy based only on magnetic resonance imaging (MRI), knowledge about tissue electron densities must be derived from the MRI. This can be achieved by converting the MRI scan to the so-called pseudo-computed tomography (pCT). An obstacle is that the voxel intensities in conventional MRI scans are not uniquely related to electron density. The authors previously demonstrated that a patch-based method could produce accurate pCTs of the brain using conventional T{sub 1}-weighted MRI scans. The method was driven mainly by local patch similarities and relied on simple affine registrations between an atlas database of the co-registered MRI/CT scan pairs and the MRI scan to be converted. In this study, the authors investigate the applicability of the patch-based approach in the pelvis. This region is challenging for a method based on local similarities due to the greater inter-patient variation. The authors benchmark the method against a baseline pCT strategy where all voxels inside the body contour are assigned a water-equivalent bulk density. Furthermore, the authors implement a parallelized approximate patch search strategy to speed up the pCT generation time to a more clinically relevant level. Methods: The data consisted of CT and T{sub 1}-weighted MRI scans of 10 prostate patients. pCTs were generated using an approximate patch search algorithm in a leave-one-out fashion and compared with the CT using frequently described metrics such as the voxel-wise mean absolute error (MAE{sub vox}) and the deviation in water-equivalent path lengths. Furthermore, the dosimetric accuracy was tested for a volumetric modulated arc therapy plan using dose–volume histogram (DVH) point deviations and γ-index analysis. Results: The patch-based approach had an average MAE{sub vox} of 54 HU; median deviations of less than 0.4% in relevant DVH points and a γ-index pass rate of 0.97 using a 1%/1 mm criterion. The patch-based approach showed a significantly better

MRI and CT findings of adult Down's syndrome

International Nuclear Information System (INIS)

Murata, Tetsuhito; Koshino, Yoshifumi; Omori, Masao

1993-01-01

Cranial CT and MRI were performed in 29 adult patients with Down's syndrome aged from 20 to 46 years to examine early aging. Morphological changes with aging, such as brain atrophy and ventricular enlargement, were generally sparse; however, calculi of the basal nucleus and lesions of deep-seated white matter were significantly increased with aging. The pallidum and putamen were shown as low intensity signals on T2-weighted images in many of patients in their fourties, suggesting their involvement in the occurrence of dyskinesia and parkinsonism symptoms that are likely to occur in the elderly. Localized changes, as shown on CT and MRI, may reflect abnormally early occurrence of aging, which precedes morphological changes such as brain atrophy. (N.K.)

Serial prenatal and postnatal MRI of dystroglycanopathy in a patient with familial B3GALNT2 mutation

Energy Technology Data Exchange (ETDEWEB)

Ho, Mai-Lan [Mayo Clinic, Department of Radiology, Rochester, MN (United States); Glenn, Orit A. [University of California, Department of Radiology, San Francisco, CA (United States); Sherr, Eliott H. [University of California, Department of Neurology, San Francisco, CA (United States); University of California, Department of Pediatrics, San Francisco, CA (United States); Strober, Jonathan B. [University of California, Department of Neurology, San Francisco, CA (United States)

2017-06-15

The dystroglycanopathies are a heterogeneous group of conditions, with mutations in B3GALNT2 described in association with congenital muscular dystrophy. The serial prenatal MRI findings in this disorder have not been well described. We present sequential prenatal and postnatal MRI findings in a boy with compound heterozygous mutations in B3GALNT2, as well as the MRI findings of his two siblings with similar mutations. These findings provide new insight into the molecular pathogenesis and neurodevelopment of congenital muscular dystrophy. (orig.)

Serial prenatal and postnatal MRI of dystroglycanopathy in a patient with familial B3GALNT2 mutation

International Nuclear Information System (INIS)

Ho, Mai-Lan; Glenn, Orit A.; Sherr, Eliott H.; Strober, Jonathan B.

2017-01-01

The dystroglycanopathies are a heterogeneous group of conditions, with mutations in B3GALNT2 described in association with congenital muscular dystrophy. The serial prenatal MRI findings in this disorder have not been well described. We present sequential prenatal and postnatal MRI findings in a boy with compound heterozygous mutations in B3GALNT2, as well as the MRI findings of his two siblings with similar mutations. These findings provide new insight into the molecular pathogenesis and neurodevelopment of congenital muscular dystrophy. (orig.)

A tool for validating MRI-guided strategies: a digital breathing CT/MRI phantom of the abdominal site.

Science.gov (United States)

Paganelli, Chiara; Summers, Paul; Gianoli, Chiara; Bellomi, Massimo; Baroni, Guido; Riboldi, Marco

2017-11-01

Dynamic magnetic resonance imaging (MRI) is emerging as the elected image modality for organ motion quantification and management in image-guided radiotherapy. However, the lack of validation tools is an open issue for image guidance in the abdominal and thoracic organs affected by organ motion due to respiration. We therefore present an abdominal four-dimensional (4D) CT/MRI digital phantom, including the estimation of MR tissue parameters, simulation of dedicated abdominal MR sequences, modeling of radiofrequency coil response and noise, followed by k-space sampling and image reconstruction. The phantom allows the realistic simulation of images generated by MR pulse sequences with control of scan and tissue parameters, combined with co-registered CT images. In order to demonstrate the potential of the phantom in a clinical scenario, we describe the validation of a virtual T1-weighted 4D MRI strategy. Specifically, the motion extracted from a T2-weighted 4D MRI is used to warp a T1-weighted breath-hold acquisition, with the aim of overcoming trade-offs that limit T1-weighted acquisitions. Such an application shows the applicability of the digital CT/MRI phantom as a validation tool, which should be especially useful for cases unsuited to obtain real imaging data.

Comparison of CT and MRI in patients with tibial plateau fracture: can CT findings predict ligament tear or meniscal injury?

International Nuclear Information System (INIS)

Mui, Leonora W.; Engelsohn, Eliyahu; Umans, Hilary

2007-01-01

(1) To determine the accuracy of computed tomography (CT) in the evaluation of ligament tear and avulsion in patients with tibial plateau fracture. (2) To evaluate whether the presence or severity of fracture gap and articular depression can predict meniscal injury. A fellowship-trained musculoskeletal radiologist retrospectively reviewed knee CT and MRI examinations of 41 consecutive patients presenting to a level 1 trauma center with tibial plateau fractures. Fracture gap, articular depression, ligament tear and footprint avulsions were assessed on CT examinations. The MRI studies were examined for osseous and soft tissue injuries, including meniscal tear, meniscal displacement, ligament tear, and ligament avulsion. CT demonstrated torn ligaments with 80% sensitivity and 98% specificity. Only 2% of ligaments deemed intact on careful CT evaluation had partial or complete tears on MRI. Although the degree of fracture gap and articular depression was significantly greater in patients with meniscal injury compared with those without meniscal injury, ROC analysis demonstrated no clear threshold for gap or depression that yielded a combination of high sensitivity and specificity. In the acute setting, CT offers high sensitivity and specificity for depicting osseous avulsions, as well as high negative predictive value for excluding ligament injury. However, MRI remains necessary for the preoperative detection of meniscal injury. (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.

CT and MRI Findings of Soft Tissue Adult Fibrosarcoma in Extremities

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Hexiang Wang

2018-01-01

Full Text Available Objective. To characterize and evaluate CT and MRI features of extremity soft tissue adult fibrosarcoma. Methods. CT and MRI images from 10 adult patients with pathologically proven fibrosarcomas were retrospectively analyzed with regard to tumor location, size, number, shape, margins, attenuation, signal intensity, and enhancement patterns on MR images. Additionally, the relationships between lesions, deep fascia, and change in adjacent bones were also assessed. Results. Nineteen tumor lesions in 10 patients were selected for this study. Eighteen lesions were lobulated and one was oval in shape. Most cases were located under the deep fascia, including seven cases that had a nodular lump adjacent to the deep fascia and one case that had broken lesion through the deep fascia. On CT, the adult fibrosarcomas mostly showed iso-attenuated soft tissue masses (n=6. On MRI, all the cases (n=9 displayed low signal on T1-weighted imaging (T1WI and heterogeneous low and high intensity signals on T2-weighted imaging (T2WI, with band-like areas of low signal on both T1WI and T2WI. On contrast-enhanced MRI images, three cases showed heterogeneous peripheral enhancement and one case demonstrated a spoke-wheel-like enhancement. Eight cases showed muscle edema signals in the peritumoral muscle and one case involved adjacent bone. Conclusion. CT and MR imaging have respective advantages in diagnosing adult fibrosarcoma. Combined application of CT and MR is recommended for patients with suspected adult fibrosarcoma.

MRI and PET/CT of patients with bone metastases from breast carcinoma

International Nuclear Information System (INIS)

Grankvist, J.; Fisker, R.; Iyer, V.; Fründ, E.T.; Simonsen, C.; Christensen, T.; Stenbygaard, L.; Ewertz, M.; Larsson, E.-M.

2012-01-01

3.0 Tesla magnetic resonance imaging (MRI) with diffusion-weighted imaging (DWI) was compared with combined 18F-fluorodeoxyglucose positron emission tomography and computed tomography (PET/CT) in patients with suspected bone metastases from breast cancer. A prospective clinical study was performed in 13 female breast cancer patients (mean age 61years; range 45–85 years). The spine was imaged in the sagittal plane with T1-weighted (T1), short tau inversion recovery (STIR), and T2-weighted fat-saturated (T2) sequences. The pelvis was imaged similarly in the coronal plane. Axial DWI was performed from the skull base to the mid-thigh. MRI and PET/CT were performed in all patients at a maximum interval of 10 working days and at least 14 days after chemotherapy. MRI was reviewed by two radiologists, and their consensus on potential metastases in 27 predefined locations was recorded. The predefined locations were the vertebral bodies (24), the left (1) and right (1) pelvic bones, and the sacral bone (1). The PET/CT was reviewed by a radiologists and a nuclear medicine physician. MRI detected 59 of the 60 active metastases found with our gold standard modality PET/CT. T1 had the highest sensitivity (98%) but rather low specificity (77%), but with the addition of STIR and DWI, the specificity increased to 95%. The additional metastases detected with MRI most likely represented postherapeutic residual scars without active tumour. In conclusion, 3.0 Tesla MRI with T1, STIR, and DWI is useful for the clinical evaluation of bone metastases from breast cancer and compares well to PET/CT.

Laryngeal amyloidosis with laryngocele: MRI and CT

International Nuclear Information System (INIS)

Arslan, A.; Ceylan, N.; Cetin, A.; Demirci, A.

1998-01-01

A case of laryngeal amyloidosis associated with a laryngocele is reported. Preoperative CT showed diffuse thickening of the epiglottis, aryepiglottic folds and false vocal cords with well-defined calcific foci. MRI revealed contrast enhancement and increased signal intensity on T2-weighted images. (orig.)

Prospective evaluation of MRI, {sup 11}C-acetate PET/CT and contrast-enhanced CT for staging of bladder cancer

Energy Technology Data Exchange (ETDEWEB)

Vargas, H.A., E-mail: vargasah@mskcc.org [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Akin, O.; Schöder, H. [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Olgac, S. [Department of Pathology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Dalbagni, G. [Department of Surgery, Urology Service, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Hricak, H. [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Bochner, B.H. [Department of Surgery, Urology Service, Memorial Sloan-Kettering Cancer Center, New York, NY (United States)

2012-12-15

Purpose: To prospectively evaluate the diagnostic performance of magnetic resonance imaging (MRI), {sup 11}C-acetate positron emission tomography/computed tomography (PET/CT) and contrast-enhanced CT for bladder cancer staging, using whole-mount pathologic review of radical cystectomy and pelvic lymph node specimens as the reference standard. Materials and methods: The institutional review board approved this prospective study, which was compliant with the Health Insurance Portability and Accountability Act. Written informed consent was obtained from 16 patients with histologically confirmed bladder cancer who underwent MRI, {sup 11}C-acetate PET/CT and contrast-enhanced CT before radical cystectomy and pelvic lymph node dissection. Before imaging 4/16 patients had received intravesical Bacillus Calmette-Guérin treatment, 6 had received systemic chemotherapy, 3 had received both and 3 had received neither. Measures of diagnostic performance including accuracy, sensitivity and specificity were estimated separately for each imaging modality. Results: MRI correctly staged 56% of patients (9/16), overstaged 38% (6/16) and understaged 6% (1/16). CT correctly staged 50% of patients (8/16), overstaged 44% (7/16) and understaged 6% (1/16). In 9 patients, {sup 11}C-acetate PET/CT showed uptake within the bladder wall; the uptake was true-positive in 7 patients and false-positive in 2 patients. Of the remaining 7 patients, 5 had true-negative and 2 had false-negative PET/CT results for cancer in the bladder wall. For all modalities, staging accuracy was reduced in patients with a history of prior intravesical and/or systemic chemotherapy. Conclusion: In staging bladder cancer, MRI, {sup 11}C-acetate PET/CT and CT displayed similar levels of accuracy. For all modalities, a history of intravesical and/or systemic chemotherapy affected staging accuracy.

Concurrent segmentation of the prostate on MRI and CT via linked statistical shape models for radiotherapy planning

International Nuclear Information System (INIS)

Chowdhury, Najeeb; Toth, Robert; Chappelow, Jonathan; Kim, Sung; Motwani, Sabin; Punekar, Salman; Lin Haibo; Both, Stefan; Vapiwala, Neha; Hahn, Stephen; Madabhushi, Anant

2012-01-01

Purpose: Prostate gland segmentation is a critical step in prostate radiotherapy planning, where dose plans are typically formulated on CT. Pretreatment MRI is now beginning to be acquired at several medical centers. Delineation of the prostate on MRI is acknowledged as being significantly simpler to perform, compared to delineation on CT. In this work, the authors present a novel framework for building a linked statistical shape model (LSSM), a statistical shape model (SSM) that links the shape variation of a structure of interest (SOI) across multiple imaging modalities. This framework is particularly relevant in scenarios where accurate boundary delineations of the SOI on one of the modalities may not be readily available, or difficult to obtain, for training a SSM. In this work the authors apply the LSSM in the context of multimodal prostate segmentation for radiotherapy planning, where the prostate is concurrently segmented on MRI and CT. Methods: The framework comprises a number of logically connected steps. The first step utilizes multimodal registration of MRI and CT to map 2D boundary delineations of the prostate from MRI onto corresponding CT images, for a set of training studies. Hence, the scheme obviates the need for expert delineations of the gland on CT for explicitly constructing a SSM for prostate segmentation on CT. The delineations of the prostate gland on MRI and CT allows for 3D reconstruction of the prostate shape which facilitates the building of the LSSM. In order to perform concurrent prostate MRI and CT segmentation using the LSSM, the authors employ a region-based level set approach where the authors deform the evolving prostate boundary to simultaneously fit to MRI and CT images in which voxels are classified to be either part of the prostate or outside the prostate. The classification is facilitated by using a combination of MRI-CT probabilistic spatial atlases and a random forest classifier, driven by gradient and Haar features

Comparative study on developmental stages of the clavicle by postmortem MRI and CT imaging

DEFF Research Database (Denmark)

Larsen, Sara Tangmose; Lynnerup, Niels; Jensen, K.E.

2013-01-01

Objectives: The developmental stages of the clavicles are important for forensic age estimation purposes in adolescents. This study compares the 4-stage system to evaluate the ossification of the medial end of the clavicle as visualized by magnetic resonance imaging (MRI) and computed tomography...... (CT). As several forensic institutes routinely perform CT scans, the large amount of available data may serve as reference sample for MRI in specific cases. Material and methods: This prospective study included an MRI and CT scan of 47 autopsy cases performed prior to medico-legal autopsy (age range...

Early response of patients undergoing concurrent chemoradiotherapy for cervical cancer. A comparison of PET/CT and MRI

International Nuclear Information System (INIS)

Lee, Jeong-Eun; Huh, Seung-Jae; Nam, Heerim; Ju, Sang-Gyu

2013-01-01

The objective of this study was to investigate the efficacy of positron emission tomography/computed tomography (PET/CT) and magnetic resonance imaging (MRI) for early response evaluation of cervical cancer patients undergoing concurrent chemoradiotherapy (CCRT). Fifty-two patients were prospectively enrolled in the study. The pathologic findings were squamous cell carcinoma in 47 patients and adenocarcinoma in 5 patients. All patients underwent PET/CT and MRI scans before, during and within 1 month after completion of CCRT. The percent change in tumor volume during and after CCRT based on PET/CT and MRI images was compared. There were significant differences (p<0.001) between the initial tumor volume and tumor volume during and after CCRT as measured by both PET/CT and MRI. During CCRT, the percent volume reduction based on PET/CT images was significantly greater than the percent volume reduction calculated from MRI images (p=0.024). However, after the completion of CCRT, no significant differences were found in volume reduction as calculated based on PET/CT versus MRI images (p=0.289). The percent volume reduction of adenocarcinomas was significantly smaller than that of squamous cell carcinomas based on both PET/CT (p=0.041) and MRI images (p<0.001). Significant decreases in tumor volume were observed during and after CCRT in patients with cervical cancer. Tumor volume reduction on PET/CT images was greater than that on MRI images during CCRT. We suggest that early PET/CT as well as MRI scans could be taken during CCRT to evaluate tumor response and allow personalized treatment of cervical cancer. (author)

Comparative benefits and limitations of 18F-FDG PET and CT-MRI in documented or suspected recurrent cervical cancer

International Nuclear Information System (INIS)

Yen, Tzu-Chen; Ma, Shih-Ya; Lai, Chyong-Huey; Huang, Kuan-Gen; Huang, Huei-Jean; Chang, Ting-Chang; Hong, Ji-Hong; Hsueh, Swei; Lin, Wuu-Jyh; Ng, Koon-Kwan

2006-01-01

The purpose of this study was to assess the comparative benefits and limitations of 18 F-fluorodeoxyglucose (FDG) PET and CT-MRI in documented or suspected recurrence of cervical cancer after primary treatment. Three patient groups were enrolled. Group A patients had biopsy-documented recurrent or persistent cervical cancer. Group B patients had suspicion of recurrent tumour on CT-MRI without biopsy proof and were potentially curable. Group C patients were in complete remission after previous definitive treatment for histologically confirmed cervical carcinoma but had elevated serum squamous cell carcinoma antigen (tumour marker) levels despite negative CT-MRI. Clinical management decisions were recorded with CT-MRI alone and with additional FDG PET. Discordances and concordances between CT-MRI and FDG PET results were identified and related to final diagnosis as based on histopathology or follow-up. A total of 150 patients (ten regions per patient) were eligible for analysis, with 58 in group A, 52 in group B and 40 in group C. For the 149 discordant regions, 126 (84.6%) had final diagnoses. Of these final diagnoses, there was additional benefit from FDG PET over CT-MRI in 73.8% (93/126), with FDG PET correcting false negatives (FNs) on CT-MRI in 74.2% (69/93) and correcting false positives (FPs) on CT-MRI in 25.8% (24/93). Among lesions confirmed by FDG PET, 75.4% (52/69) were extra-pelvic. There was additional benefit of CT-MRI compared with FDG PET in 26.2% (33/126): in nine (27.3%) CT-MRI results were shown to be true positive (TP) whereas FDG PET yielded FN results, while in 24 (72.7%) CT-MRI corrected FP results on FDG PET. Among the nine FNs on FDG PET that were identified by CT-MRI, four were extra-pelvic. Among the FPs on FDG PET that were excluded by CT-MRI, 79.2% (19/24) were extra-pelvic. For recurrent cervical cancer, the benefits of FDG PET exceed those of CT-MRI owing to the ability of FDG PET to identify extra-pelvic metastases and its higher

Comparative evaluation of 11C-MET PET-CT and MRI for GTV delineation in precision radiotherapy for gliomas

International Nuclear Information System (INIS)

Wang Ru; Qian Liting; Wang Shicun; Liu Wei; Luo Wenguang; Zhang Hongbo; Li Guanghu; Hu Zhigang; Liu Lei

2014-01-01

Objective: To evaluate the difference between MRI and 11 C-MET PET-CT for gross tumor volume (GTV) delineation in the precision radiotherapy for gliomas. Methods: Six patients with a pathologically confirmed diagnosis of gliomas were selected for target delineation. Five physicians in our department were called to delineate the GTV based on the preoperative MRI and 11 C-MET PET-CT images of these patients. The GTVs based on the two methods were compared. Results: There was no significant difference between the GTVs based on MRI and 11 C-MET PET-CT (P=0.917), and their coefficients of variation were also similar (P=0.600). The coincidences of GTVs were different among the patients, with a maximum value of 73.0% and a minimum value of 51.8%. GTV showed no significant difference when defined by different physicians on MRI and PET-CT (P=0.709); the biggest difference was 27.66 cm 3 on PET-CT and 40.37 cm 3 on MRI. Conclusions: The boundaries of gliomas defined on MRI and PET-CT are different. The GTVs delineated by different physicians on MRI and PET-CT are similar, and the biggest difference on PET-CT is smaller than that on MRI, which suggests that 11 C-MET PET-CT is a more direct way for displaying GTV. (authors)

Three-dimensional contrasted visualization of pancreas in rats using clinical MRI and CT scanners.

Science.gov (United States)

Yin, Ting; Coudyzer, Walter; Peeters, Ronald; Liu, Yewei; Cona, Marlein Miranda; Feng, Yuanbo; Xia, Qian; Yu, Jie; Jiang, Yansheng; Dymarkowski, Steven; Huang, Gang; Chen, Feng; Oyen, Raymond; Ni, Yicheng

2015-01-01

The purpose of this work was to visualize the pancreas in post-mortem rats with local contrast medium infusion by three-dimensional (3D) magnetic resonance imaging (MRI) and computed tomography (CT) using clinical imagers. A total of 16 Sprague Dawley rats of about 300 g were used for the pancreas visualization. Following the baseline imaging, a mixed contrast medium dye called GadoIodo-EB containing optimized concentrations of Gd-DOTA, iomeprol and Evens blue was infused into the distally obstructed common bile duct (CBD) for post-contrast imaging with 3.0 T MRI and 128-slice CT scanners. Images were post-processed with the MeVisLab software package. MRI findings were co-registered with CT scans and validated with histomorphology, with relative contrast ratios quantified. Without contrast enhancement, the pancreas was indiscernible. After infusion of GadoIodo-EB solution, only the pancreatic region became outstandingly visible, as shown by 3D rendering MRI and CT and proven by colored dissection and histological examinations. The measured volume of the pancreas averaged 1.12 ± 0.04 cm(3) after standardization. Relative contrast ratios were 93.28 ± 34.61% and 26.45 ± 5.29% for MRI and CT respectively. We have developed a multifunctional contrast medium dye to help clearly visualize and delineate rat pancreas in situ using clinical MRI and CT scanners. The topographic landmarks thus created with 3D demonstration may help to provide guidelines for the next in vivo pancreatic MRI research in rodents. Copyright © 2015 John Wiley & Sons, Ltd.

CT and MRI diagnosis of chondrosarcoma in sinonasal and orbital region

International Nuclear Information System (INIS)

Yang Bentao; Wang Zhenchang; Xian Junfang; Zhang Zhengyu; Liu Zhonglin; Lan Baosen

2006-01-01

Objective: To investigate the CT and MRI findings of chondrosarcoma in sinonasal and orbital region so as to promote the diagnostic accuracy. Methods: All 12 cases of chondrosarcoma were verified by pathology. CT and MRI findings were analyzed retrospectively. Results: The lesions occurred in sinonasal cavity in 9 cases and in orbit in 3 cases. Pathologically 8 cases were conventional chondrosarcoma, 2 dedifferentiated chondrosarcoma, and 2 mesenchymal chondrosarcoma. On CT, chondrosarcoma revealed oval shape in 2 cases, lobular shape in 6 cases and irregular shape in 4 cases. The lesion showed stippled, ring, nodular, patchy or amorphous calcification. Postcontrast CT showed mild inhomogeneous enhancement in 3 cases. Chondrosarcoma demonstrated well-defined margin in 9 cases and hazy margin in 3 cases. Sinonasal chondrosarcoma revealed bony destruction in 7 cases. Orbital chondrosarcoma showed bony erosion invading ipsilateral frontal region in one case. On MR T 1 WI, conventional and dedifferentiated chondrosarcoma showed hypointense signal compared to brain in 6 cases and isointense signal in 4 cases. On T 2 WI, the lesions showed heterogeneous hyperintense signal in 8 cases and isointense signal in 2 cases with marked hypointense foci. Postcontrast MR imaging demonstrated mild to moderate inhomogeneous enhancement in these cases, and showed peripheral and septal enhancement in 5 cases of conventional chondrosarcoma, showing variegated appearance in 3 cases and honeycomb-like appearance in 2 cases. Mesenchymal chondrosarcoma showed isointense signal on both T 1 WI and T 2 WI, with homogeneous and heterogeneous enhancement in one case, respectively. MRI showed the extent and the associated changes of the lesions more clearly compared to CT. Conclusion: CT is the first modality of choice in the diagnosis of chondrosarcoma in sinonasal and orbital region. The typically peripheral and septal contrast enhancement can also suggest the diagnosis of chondrosarcoma on

Intracranial alveolar echinococcosis: CT and MRI

International Nuclear Information System (INIS)

Bensaid, A.H.; Dietemann, J.L.; Filippi de la Palavesa, M.M.; Klinkert, A.; Kastler, B.; Gangi, A.; Jacquet, G.; Cattin, F.

1994-01-01

Intracranial alveolar echinococcosis is uncommon. We report a patient with right frontal lobe and palpebral lesions secondary to a primary hepatic focus with secondary lesion in the lung. The intracranial and palpebral cystic masses were totally removed and both proved to be alveolar hydatid cysts. An unusual feature in this case is CT and MRI demonstration of dural and bony extension. (orig.)

Intracranial alveolar echinococcosis: CT and MRI

Energy Technology Data Exchange (ETDEWEB)

Bensaid, A.H. (Dept. of Radiology B, Univ. Hospital, Strasbourg (France)); Dietemann, J.L. (Dept. of Radiology B, Univ. Hospital, Strasbourg (France)); Filippi de la Palavesa, M.M. (Dept. of Radiology B, Univ. Hospital, Strasbourg (France)); Klinkert, A. (Dept. of Radiology B, Univ. Hospital, Strasbourg (France)); Kastler, B. (Dept. of Radiology B, Univ. Hospital, Strasbourg (France)); Gangi, A. (Dept. of Radiology B, Univ. Hospital, Strasbourg (France)); Jacquet, G. (Dept. of Neurosurgery, Univ. Hospital, Besancon (France)); Cattin, F. (Dept. of Radiology, Univ. Hospital, Besancon (France))

1994-05-01

Intracranial alveolar echinococcosis is uncommon. We report a patient with right frontal lobe and palpebral lesions secondary to a primary hepatic focus with secondary lesion in the lung. The intracranial and palpebral cystic masses were totally removed and both proved to be alveolar hydatid cysts. An unusual feature in this case is CT and MRI demonstration of dural and bony extension. (orig.)

Prospective evaluation of 18F-FACBC PET/CT and PET/MRI versus multiparametric MRI in intermediate- to high-risk prostate cancer patients (FLUCIPRO trial).

Science.gov (United States)

Jambor, Ivan; Kuisma, Anna; Kähkönen, Esa; Kemppainen, Jukka; Merisaari, Harri; Eskola, Olli; Teuho, Jarmo; Perez, Ileana Montoya; Pesola, Marko; Aronen, Hannu J; Boström, Peter J; Taimen, Pekka; Minn, Heikki

2018-03-01

The purpose of this study was to evaluate 18 F-FACBC PET/CT, PET/MRI, and multiparametric MRI (mpMRI) in detection of primary prostate cancer (PCa). Twenty-six men with histologically confirmed PCa underwent PET/CT immediately after injection of 369 ± 10 MBq 18 F-FACBC (fluciclovine) followed by PET/MRI started 55 ± 7 min from injection. Maximum standardized uptake values (SUV max ) were measured for both hybrid PET acquisitions. A separate mpMRI was acquired within a week of the PET scans. Logan plots were used to calculate volume of distribution (V T ). The presence of PCa was estimated in 12 regions with radical prostatectomy findings as ground truth. For each imaging modality, area under the curve (AUC) for detection of PCa was determined to predict diagnostic performance. The clinical trial registration number is NCT02002455. In the visual analysis, 164/312 (53%) regions contained PCa, and 41 tumor foci were identified. PET/CT demonstrated the highest sensitivity at 87% while its specificity was low at 56%. The AUC of both PET/MRI and mpMRI significantly (p PET/CT while no differences were detected between PET/MRI and mpMRI. SUV max and V T of Gleason score (GS) >3 + 4 tumors were significantly (p PET/CT and PET/MRI demonstrated true-positive findings in only 1/7 patients with metastatic lymph nodes. Quantitative 18 F-FACBC imaging significantly correlated with GS but failed to outperform MRI in lesion detection. 18 F-FACBC may assist in targeted biopsies in the setting of hybrid imaging with MRI.

Comparison of 11C-choline-PET/CT and whole body-MRI for staging of prostate cancer

International Nuclear Information System (INIS)

Eschmann, S.M.; Rieger, A.; Mueller, M.; Bares, R.; Pfannenberg, A.C.; Aschoff, P.; Claussen, C.D.; Schlemmer, H.P.; Paulsen, F.; Anastasiadis, A.

2007-01-01

Aim of this study was to compare the diagnostic accuracy of positron emission tomography and computed tomography with 11 C-Choline (Cho-PET/CT) and whole body magneticresonance imaging (WB-MRI) for diagnostic work-up of prostate cancer. Patients, methods: We evaluated retrospectively 42 patients with untreated prostate cancer (n =17), or increasing levels of prostate-specific antigen (PSA) after curative therapy (n = 25) who had been investigated by both Cho-PET/CT and WB-MRI. MRI, CT, and PET images were separately analyzed by experienced radiologists or nuclear medicine experts, followed by consensus reading. Validation was established by histology, follow-up, or consensus reading. Results: 88/103 detected lesions were considered as malignant: 44 bone metastases, 22 local tumor, 15 lymph node metastases, 3 lung, and 3 brain metastases. One further lesion was located in the adrenal gland, which was a second tumor. Overall sensitivity, specificity and accuracy for Cho-PET/CT were 96.6%, 76.5%, and 93.3%, resp., and for WB-MRI 78.4%, 94.1%, and 81.0%, resp. 3 vertebral metastases had initially been missed by Cho-PET/CT and were found retrospectively. MRI identified 2 bone metastases and 1 lymph node metastasis after being informed about the results of Cho-PET/CT. Conclusions: Cho-PET/CT and WB-MRI both presented high accuracy in the detection of bone and lymph node metastases. The strength of MRI is excellent image quality providing detailed anatomical information whereas the advantage of Cho-PET/CT is high image contrast of pathological foci. (orig.)

CT and MRI in progressive multifocal leukoencephalopathy. CT und MRT der progressiven multifokalen Leukenzephalopathie (PML)

Energy Technology Data Exchange (ETDEWEB)

Lanfermann, H. (Inst. und Poliklinik fuer Radiologische Diagnostik, Koeln Univ. (Germany)); Heindel, W. (Inst. und Poliklinik fuer Radiologische Diagnostik, Koeln Univ. (Germany)); Schroeder, R. (Neuropathologie des Inst. fuer Pathologie, Koeln Univ. (Germany)); Lackner, K. (Inst. und Poliklinik fuer Radiologische Diagnostik, Koeln Univ. (Germany))

1994-07-01

Radiological findings and course of progressive multifocal leukoencephalopathy in 14 patients (1 woman, 13 men; 13 HIV seropositive, 1 chronic lymphatic leukaemia) were analysed retrospectively and correlated with clinical symptoms. A total of 21 CT and 16 MRI studies were evaluated. CT scans and MR images of 9 patients, which had been obtained in less than two weeks, could be compared to each other. MRI was superior to CT: 6 lesions with a diameter of 1 cm and below were not detected on CT scans, in 5 patients the extent of lesions was underestimated. Cortical involvement, mass effect or signs of atrophy were missing. Only 1 of 65 lesions showed a tiny enhancement after Gd injection. Due to the pattern and spread of lesions, which showed a close correlation to the neurologic symptoms, three different types of PML are suggested: 1. Initial precentral demyelinisation with contralateral hemiparesis (n=8); 2. lesions in temporo-occipital locations with visual disturbances (n=2); 3. predominantly bilateral lesions of cerebellar white matter with ataxia (n=4). (orig.)

Robust inverse-consistent affine CT-MR registration in MRI-assisted and MRI-alone prostate radiation therapy.

Science.gov (United States)

Rivest-Hénault, David; Dowson, Nicholas; Greer, Peter B; Fripp, Jurgen; Dowling, Jason A

2015-07-01

CT-MR registration is a critical component of many radiation oncology protocols. In prostate external beam radiation therapy, it allows the propagation of MR-derived contours to reference CT images at the planning stage, and it enables dose mapping during dosimetry studies. The use of carefully registered CT-MR atlases allows the estimation of patient specific electron density maps from MRI scans, enabling MRI-alone radiation therapy planning and treatment adaptation. In all cases, the precision and accuracy achieved by registration influences the quality of the entire process. Most current registration algorithms do not robustly generalize and lack inverse-consistency, increasing the risk of human error and acting as a source of bias in studies where information is propagated in a particular direction, e.g. CT to MR or vice versa. In MRI-based treatment planning where both CT and MR scans serve as spatial references, inverse-consistency is critical, if under-acknowledged. A robust, inverse-consistent, rigid/affine registration algorithm that is well suited to CT-MR alignment in prostate radiation therapy is presented. The presented method is based on a robust block-matching optimization process that utilises a half-way space definition to maintain inverse-consistency. Inverse-consistency substantially reduces the influence of the order of input images, simplifying analysis, and increasing robustness. An open source implementation is available online at http://aehrc.github.io/Mirorr/. Experimental results on a challenging 35 CT-MR pelvis dataset demonstrate that the proposed method is more accurate than other popular registration packages and is at least as accurate as the state of the art, while being more robust and having an order of magnitude higher inverse-consistency than competing approaches. The presented results demonstrate that the proposed registration algorithm is readily applicable to prostate radiation therapy planning. Copyright © 2015. Published by

Carpal angles as measured on CT and MRI: can we simply translate radiographic measurements?

Energy Technology Data Exchange (ETDEWEB)

Tan, Stephanie; Ghumman, Simranjit S.; Moser, Thomas P. [Hopital Notre-Dame (CHUM), Department of Radiology, Centre Hospitalier de l' Universite de Montreal, Montreal, QC (Canada); Ladouceur, Martin [Research Center CHUM, Montreal, QC (Canada)

2014-12-15

To determine the reliability of carpal angles measured on CT and MRI compared to radiography and assess if these measurements are interchangeable. Our institutional ethic research committee approved this study. For this retrospective study, two independent observers measured the scapholunate (SL), capitolunate (CL), radiolunate (RL), and radioscaphoid (RS) angles on 21 sets of exams, with each set including a radiograph, CT, and MRI of the same wrist. Inter- and intra-observer agreements were evaluated with the intraclass correlation coefficient (ICC). Linear mixed models and two-way contingency tables were used to determine if the angles measured on cross-sectional modalities were significantly different from those obtained on radiography. Inter-observer agreement was strong (ICC >0.8) for all angles, except for the RL angle measured on MRI (ICC 0.68). Intra-observer agreement was also strong for all angles, except for the CL angle measured on CT (ICC 0.66). SL angles measured on CT and MRI were not statistically different from those measured on radiographs (p = 0.37 and 0.36, respectively), unlike CL, RL, and RS angles (p < 0.05). Accuracy between modalities varied between 76 and 86 % for the SL angle and ranged between 43 and 76 % for the other angles. CL, RL, and RS angles showed large intermodality variability. Therefore, their measurements on CT or MRI could potentially lead to miscategorization. Conversely, our data showing no significant difference between modalities, SL angle could be measured on CT and MRI to assess wrist instability with a lower risk of error. (orig.)

The usefulness of brain MRI and CT in the clinical practice of epilepsia

Energy Technology Data Exchange (ETDEWEB)

Horita, Hideki [Jikei Univ., Komae, Tokyo (Japan). Daisan Hospital; Maekawa, Kihei

1995-09-01

This study was conducted to clarify the usefulness of brain MRI and CT in the clinical practice of epilepsy. The subjects were 100 epileptic child patients (average age, 13.2{+-}8.2 years) who underwent brain MRI, including 93 patients who also underwent brain CT. Twenty-two abnormal findings were obtained by MRI and 25 by CT. Thirty-nine patients who had complications such as mental retardation, cerebral palsy, or the overlapping disorders showed abnormal findings in a significantly high incidence. No significant correlations existed between the presence or absence of abnormal findings and the disease course after seizures. Patients with symptomatic localization-related epilepsies or cryptogenic and symptomatic generalized epilepsies showed abnormal findings in a significantly high incidence and unfavorable disease course after seizures. In 10 of 28 patients who showed abnormal findings, the abnormal finding site on images were correlated to the focus site on electroencephalograms. In conclusion, brain MRI and CT are essential in the clinical practice of epilepsy, however, we should notice the limitation of these methods. (Y.S.).

The usefulness of brain MRI and CT in the clinical practice of epilepsia

International Nuclear Information System (INIS)

Horita, Hideki; Maekawa, Kihei.

1995-01-01

This study was conducted to clarify the usefulness of brain MRI and CT in the clinical practice of epilepsy. The subjects were 100 epileptic child patients (average age, 13.2±8.2 years) who underwent brain MRI, including 93 patients who also underwent brain CT. Twenty-two abnormal findings were obtained by MRI and 25 by CT. Thirty-nine patients who had complications such as mental retardation, cerebral palsy, or the overlapping disorders showed abnormal findings in a significantly high incidence. No significant correlations existed between the presence or absence of abnormal findings and the disease course after seizures. Patients with symptomatic localization-related epilepsies or cryptogenic and symptomatic generalized epilepsies showed abnormal findings in a significantly high incidence and unfavorable disease course after seizures. In 10 of 28 patients who showed abnormal findings, the abnormal finding site on images were correlated to the focus site on electroencephalograms. In conclusion, brain MRI and CT are essential in the clinical practice of epilepsy, however, we should notice the limitation of these methods. (Y.S.)

TH-CD-206-09: Learning-Based MRI-CT Prostate Registration Using Spare Patch-Deformation Dictionary

International Nuclear Information System (INIS)

Yang, X; Jani, A; Rossi, P; Mao, H; Curran, W; Liu, T

2016-01-01

Purpose: To enable MRI-guided prostate radiotherapy, MRI-CT deformable registration is required to map the MRI-defined tumor and key organ contours onto the CT images. Due to the intrinsic differences in grey-level intensity characteristics between MRI and CT images, the integration of MRI into CT-based radiotherapy is very challenging. We are developing a learning-based registration approach to address this technical challenge. Methods: We propose to estimate the deformation between MRI and CT images in a patch-wise fashion by using the sparse representation technique. Specifically, we assume that two image patches should follow the same deformation if their patch-wise appearance patterns are similar. We first extract a set of key points in the new CT image. Then, for each key point, we adaptively construct a coupled dictionary from the training MRI-CT images, where each coupled element includes both appearance and deformation of the same image patch. After calculating the sparse coefficients in representing the patch appearance of each key point based on the constructed dictionary, we can predict the deformation for this point by applying the same sparse coefficients to the respective deformations in the dictionary. Results: This registration technique was validated with 10 prostate-cancer patients’ data and its performance was compared with the commonly used free-form-deformation-based registration. Several landmarks in both images were identified to evaluate the accuracy of our approach. Overall, the averaged target registration error of the intensity-based registration and the proposed method was 3.8±0.4 mm and 1.9±0.3 mm, respectively. Conclusion: We have developed a novel prostate MR-CT registration approach based on patch-deformation dictionary, demonstrated its clinical feasibility, and validated its accuracy. This technique will either reduce or compensate for the effect of patient-specific treatment variation measured during the course of

TH-CD-206-09: Learning-Based MRI-CT Prostate Registration Using Spare Patch-Deformation Dictionary

Energy Technology Data Exchange (ETDEWEB)

Yang, X; Jani, A; Rossi, P; Mao, H; Curran, W; Liu, T [Emory University, Atlanta, GA (United States)

2016-06-15

Purpose: To enable MRI-guided prostate radiotherapy, MRI-CT deformable registration is required to map the MRI-defined tumor and key organ contours onto the CT images. Due to the intrinsic differences in grey-level intensity characteristics between MRI and CT images, the integration of MRI into CT-based radiotherapy is very challenging. We are developing a learning-based registration approach to address this technical challenge. Methods: We propose to estimate the deformation between MRI and CT images in a patch-wise fashion by using the sparse representation technique. Specifically, we assume that two image patches should follow the same deformation if their patch-wise appearance patterns are similar. We first extract a set of key points in the new CT image. Then, for each key point, we adaptively construct a coupled dictionary from the training MRI-CT images, where each coupled element includes both appearance and deformation of the same image patch. After calculating the sparse coefficients in representing the patch appearance of each key point based on the constructed dictionary, we can predict the deformation for this point by applying the same sparse coefficients to the respective deformations in the dictionary. Results: This registration technique was validated with 10 prostate-cancer patients’ data and its performance was compared with the commonly used free-form-deformation-based registration. Several landmarks in both images were identified to evaluate the accuracy of our approach. Overall, the averaged target registration error of the intensity-based registration and the proposed method was 3.8±0.4 mm and 1.9±0.3 mm, respectively. Conclusion: We have developed a novel prostate MR-CT registration approach based on patch-deformation dictionary, demonstrated its clinical feasibility, and validated its accuracy. This technique will either reduce or compensate for the effect of patient-specific treatment variation measured during the course of

Value of fusion of PET and MRI for staging of endometrial cancer: Comparison with 18F-FDG contrast-enhanced PET/CT and dynamic contrast-enhanced pelvic MRI

International Nuclear Information System (INIS)

Kitajima, Kazuhiro; Suenaga, Yuko; Ueno, Yoshiko; Kanda, Tomonori; Maeda, Tetsuo; Takahashi, Satoru; Ebina, Yasuhiko; Miyahara, Yoshiya; Yamada, Hideto; Sugimura, Kazuro

2013-01-01

Purpose: To investigate the diagnostic value of retrospective fusion of pelvic MRI and 18 F-fluorodeoxyglucose ( 18 F-FDG) PET images for assessment of locoregional extension and nodal staging of endometrial cancer. Materials and methods: Thirty patients with biopsy-proven endometrial cancer underwent preoperative contrast-enhanced PET/CT (PET/ceCT) and pelvic dynamic contrast-enhanced MRI for initial staging. Diagnostic performance of PET/ceCT, contrast-enhanced MRI, and retrospective image fusion from PET and MRI (fused PET/MRI) for assessing the extent of the primary tumor (T stage) and metastasis to regional LNs (N stage) was evaluated by two experienced readers. Histopathological and follow-up imaging results were used as the gold standard. The McNemar test was employed for statistical analysis. Results: Fused PET/MRI and MRI detected 96.7% of the primary tumors, whereas PET/ceCT detected 93.3%. Accuracy for T status was 80.0% for fused PET/MRI, and MRI proved significantly more accurate than PET/ceCT, which had an accuracy of 60.0% (p = 0.041). Patient-based sensitivity, specificity and accuracy for detecting pelvic nodal metastasis were 100%, 96.3% and 96.7% for both fused PET/MRI and PET/ceCT, and 66.7%, 100% and 96.7% for MRI, respectively. These three parameters were not statistically significant (p = 1). Conclusion: Fused PET/MRI, which complements the individual advantages of MRI and PET, is a valuable technique for assessment of the primary tumor and nodal staging in patients with endometrial cancer

SU-E-J-226: Efficient Use of Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) for Cervical-Cancer Brachytherapy

Energy Technology Data Exchange (ETDEWEB)

Damato, A; Bhagwat, M; Buzurovic, I; Cormack, R; Lee, L; Viswanathan, A [Harvard Medical School, Boston, MA (United States)

2015-06-15

Purpose: To investigate image modality selection in an environment with limited access to interventional MRI for image-guided high-dose-rate cervical-cancer brachytherapy. Methods: Records of all cervical-cancer patients treated with brachytherapy between 1/2013 and 8/2014 were analyzed. Insertions were performed under CT guidance (CT group) or with >1 fraction under 3T MR guidance (MRI group; subMRI includes only patients who also had a CT-guided insertion). Differences between groups in clinical target volume (CTV), disease stage (I/II or III/IV), number of patients with or without interstitial needles, and CTV D90 were investigated. Statistical significance was evaluated with the Student T test and Fisher test (p <0.05). Results: 46 cervical-cancer patients were included (16 MRI [3 subMRI], 30 CT). CTV: overall, 55±53 cm3; MRI, 81±61 cm3; CT, 42±44 cm3 (p = 0.017). Stage: overall, 24 I/II and 22 III/IV; MRI, 3 I/II and 13 III/IV; CT, 21 I/II and 9 III/IV (p = 0.002). Use of needles: overall, 26 without and 20 with; MRI, 5 without and 11 with; CT, 21 without and 9 with (p = 0.015). CTV D90: overall, 82±5 Gy; MRI, 81±6 Gy; CT, 82±5 Gy (p = 0.78). SubMRI: CTV and D90 (as % of nominal fraction dose) were 23±6 cm3 and 124±3% for MRI-guided insertions and 21±5 cm3 (p = 0.83) and 106±12% (p = 0.15) for CT-guided insertions. Conclusion: Statistically significant differences in patient population indicate preferential use of MRI for patients with high-stage disease and large residual CTVs requiring the use of interstitial needles. CTV D90 was similar between groups, despite the difference in patient selection. For patients who underwent both CT and MRI insertions, a larger MR CTV D90 and similar CTVs between insertions were observed. While MRI is generally preferable to CT, MRI selection can be optimized in environments without a dedicated MRI brachytherapy suite. This work was partially funded by the NIH R21 CA167800 (PI: Viswanathan; aviswanathan@partners.org)

SU-E-J-226: Efficient Use of Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) for Cervical-Cancer Brachytherapy

International Nuclear Information System (INIS)

Damato, A; Bhagwat, M; Buzurovic, I; Cormack, R; Lee, L; Viswanathan, A

2015-01-01

Purpose: To investigate image modality selection in an environment with limited access to interventional MRI for image-guided high-dose-rate cervical-cancer brachytherapy. Methods: Records of all cervical-cancer patients treated with brachytherapy between 1/2013 and 8/2014 were analyzed. Insertions were performed under CT guidance (CT group) or with >1 fraction under 3T MR guidance (MRI group; subMRI includes only patients who also had a CT-guided insertion). Differences between groups in clinical target volume (CTV), disease stage (I/II or III/IV), number of patients with or without interstitial needles, and CTV D90 were investigated. Statistical significance was evaluated with the Student T test and Fisher test (p <0.05). Results: 46 cervical-cancer patients were included (16 MRI [3 subMRI], 30 CT). CTV: overall, 55±53 cm3; MRI, 81±61 cm3; CT, 42±44 cm3 (p = 0.017). Stage: overall, 24 I/II and 22 III/IV; MRI, 3 I/II and 13 III/IV; CT, 21 I/II and 9 III/IV (p = 0.002). Use of needles: overall, 26 without and 20 with; MRI, 5 without and 11 with; CT, 21 without and 9 with (p = 0.015). CTV D90: overall, 82±5 Gy; MRI, 81±6 Gy; CT, 82±5 Gy (p = 0.78). SubMRI: CTV and D90 (as % of nominal fraction dose) were 23±6 cm3 and 124±3% for MRI-guided insertions and 21±5 cm3 (p = 0.83) and 106±12% (p = 0.15) for CT-guided insertions. Conclusion: Statistically significant differences in patient population indicate preferential use of MRI for patients with high-stage disease and large residual CTVs requiring the use of interstitial needles. CTV D90 was similar between groups, despite the difference in patient selection. For patients who underwent both CT and MRI insertions, a larger MR CTV D90 and similar CTVs between insertions were observed. While MRI is generally preferable to CT, MRI selection can be optimized in environments without a dedicated MRI brachytherapy suite. This work was partially funded by the NIH R21 CA167800 (PI: Viswanathan; aviswanathan@partners.org)

Diagnostic Accuracy of MRI Versus CT for the Evaluation of Acute Appendicitis in Children and Young Adults.

Science.gov (United States)

Kinner, Sonja; Pickhardt, Perry J; Riedesel, Erica L; Gill, Kara G; Robbins, Jessica B; Kitchin, Douglas R; Ziemlewicz, Timothy J; Harringa, John B; Reeder, Scott B; Repplinger, Michael D

2017-10-01

Appendicitis is frequently diagnosed in the emergency department, most commonly using CT. The purpose of this study was to compare the diagnostic accuracy of contrast-enhanced MRI with that of contrast-enhanced CT for the diagnosis of appendicitis in adolescents when interpreted by abdominal radiologists and pediatric radiologists. Our study included a prospectively enrolled cohort of 48 patients (12-20 years old) with nontraumatic abdominal pain who underwent CT and MRI. Fellowship-trained abdominal and pediatric radiologists reviewed all CT and MRI studies in randomized order, blinded to patient outcome. Likelihood for appendicitis was rated on a 5-point scale (1, definitely not appendicitis; 5, definitely appendicitis) for CT, the unenhanced portion of the MRI, and the entire contrast-enhanced MRI study. ROC curves were generated and AUC compared for each scan type for all six readers and then stratified by radiologist type. Image test characteristics, interrater reliability, and reading times were compared. Sensitivity and specificity were 85.9% (95% CI, 76.2-92.7%) and 93.8% (95% CI, 89.7-96.7%) for unenhanced MRI, 93.6% (95% CI, 85.6-97.9%) and 94.3% (95% CI, 90.2-97%) for contrast-enhanced MRI, and 93.6% (95% CI, 85.6-97.9%) and 94.3% (95% CI, 90.2-97%) for CT. No difference was found in the diagnostic accuracy or interpretation time when comparing abdominal radiologists to pediatric radiologists (CT, 3.0 min vs 2.8 min; contrast-enhanced MRI, 2.4 min vs 1.8 min; unenhanced MRI, 1.5 min vs 2.3 min). Substantial agreement between abdominal and pediatric radiologists was seen for all methods (κ = 0.72-0.83). The diagnostic accuracy of MRI to diagnose appendicitis was very similar to CT. No statistically significant difference in accuracy was observed between imaging modality or radiologist subspecialty.

Quantitative Assessment of Degenerative Cartilage and Subchondral Bony Lesions in a Preserved Cadaveric Knee: Propagation-Based Phase-Contrast CT Versus Conventional MRI and CT.

Science.gov (United States)

Geith, Tobias; Brun, Emmanuel; Mittone, Alberto; Gasilov, Sergei; Weber, Loriane; Adam-Neumair, Silvia; Bravin, Alberto; Reiser, Maximilian; Coan, Paola; Horng, Annie

2018-04-09

The aim of this study was to quantitatively assess hyaline cartilage and subchondral bone conditions in a fully preserved cadaveric human knee joint using high-resolution x-ray propagation-based phase-contrast imaging (PBI) CT and to compare the performance of the new technique with conventional CT and MRI. A cadaveric human knee was examined using an x-ray beam of 60 keV, a detector with a 90-mm 2 FOV, and a pixel size of 46 × 46 μm 2 . PBI CT images were reconstructed with both the filtered back projection algorithm and the equally sloped tomography method. Conventional 3-T MRI and CT were also performed. Measurements of cartilage thickness, cartilage lesions, International Cartilage Repair Society scoring, and detection of subchondral bone changes were evaluated. Visual inspection of the specimen akin to arthroscopy was conducted and served as a standard of reference for lesion detection. Loss of cartilage height was visible on PBI CT and MRI. Quantification of cartilage thickness showed a strong correlation between the two modalities. Cartilage lesions appeared darker than the adjacent cartilage on PBI CT. PBI CT showed similar agreement to MRI for depicting cartilage substance defects or lesions compared with the visual inspection. The assessment of subchondral bone cysts showed moderate to strong agreement between PBI CT and CT. In contrast to the standard clinical methods of MRI and CT, PBI CT is able to simultaneously depict cartilage and bony changes at high resolution. Though still an experimental technique, PBI CT is a promising high-resolution imaging method to evaluate comprehensive changes of osteoarthritic disease in a clinical setting.

[{sup 18}F]FDG PET/CT outperforms [{sup 18}F]FDG PET/MRI in differentiated thyroid cancer

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Vrachimis, Alexis; Wenning, Christian; Weckesser, Matthias; Stegger, Lars [University Hospital Muenster, Department of Nuclear Medicine, Muenster (Germany); Burg, Matthias Christian; Allkemper, Thomas [University Hospital Muenster, Department of Clinical Radiology, Muenster (Germany); Schaefers, Michael [University Hospital Muenster, Department of Nuclear Medicine, Muenster (Germany); Westfaelische Wilhelms University Muenster, European Institute for Molecular Imaging, Muenster (Germany)

2016-02-15

To evaluate the diagnostic potential of PET/MRI with [{sup 18}F]FDG in comparison to PET/CT in patients with differentiated thyroid cancer suspected or known to have dedifferentiated. The study included 31 thyroidectomized and remnant-ablated patients who underwent a scheduled [{sup 18}F]FDG PET/CT scan and were then enrolled for a PET/MRI scan of the neck and thorax. The datasets (PET/CT, PET/MRI) were rated regarding lesion count, conspicuity, diameter and characterization. Standardized uptake values were determined for all [{sup 18}F]FDG-positive lesions. Histology, cytology, and examinations before and after treatment served as the standards of reference. Of 26 patients with a dedifferentiated tumour burden, 25 were correctly identified by both [{sup 18}F]FDG PET/CT and PET/MRI. Detection rates by PET/CT and PET/MRI were 97 % (113 of 116 lesions) and 85 % (99 of 113 lesions) for malignant lesions, and 100 % (48 of 48 lesions) and 77 % (37 of 48 lesions) for benign lesions, respectively. Lesion conspicuity was higher on PET/CT for both malignant and benign pulmonary lesions and in the overall rating for malignant lesions (p < 0.001). There was a difference between PET/CT and PET/MRI in overall evaluation of malignant lesions (p < 0.01) and detection of pulmonary metastases (p < 0.001). Surgical evaluation revealed three malignant lesions missed by both modalities. PET/MRI additionally failed to detect 14 pulmonary metastases and 11 benign lesions. In patients with thyroid cancer and suspected or known dedifferentiation, [{sup 18}F]FDG PET/MRI was inferior to low-dose [{sup 18}F]FDG PET/CT for the assessment of pulmonary status. However, for the assessment of cervical status, [{sup 18}F]FDG PET/MRI was equal to contrast-enhanced neck [{sup 18}F]FDG PET/CT. Therefore, [{sup 18}F]FDG PET/MRI combined with a low-dose CT scan of the thorax may provide an imaging solution when high-quality imaging is needed and high-energy CT is undesirable or the use of a contrast

Preclinical Multimodal Molecular Imaging Using 18F-FDG PET/CT and MRI in a Phase I Study of a Knee Osteoarthritis in In Vivo Canine Model

Directory of Open Access Journals (Sweden)

Maria I. Menendez DVM, PhD

2017-03-01

Full Text Available The aim of this study was to use a multimodal molecular imaging approach to serially assess regional metabolic changes in the knee in an in vivo anterior cruciate ligament transection (ACLT canine model of osteoarthritis (OA. Five canine underwent ACLT in one knee and the contralateral knee served as uninjured control. Prior, 3, 6, and 12 weeks post-ACLT, the dogs underwent 18F-fluoro-d-glucose (18F-FDG positron emission tomography (PET/computed tomography (CT and magnetic resonance imaging (MRI. The MRI was coregistered with the PET/CT, and 3-dimensional regions of interest (ROIs were traced manually and maximum standardized uptake values (SUVmax were evaluated. 18F-fluoro-d-glucose SUVmax in the ACLT knee ROIs was significantly higher compared to the uninjured contralateral knees at 3, 6, and 12 weeks. Higher 18F-FDG uptake observed in ACLT knees compared to the uninjured knees reflects greater metabolic changes in the injured knees over time. Knee 18F-FDG uptake in an in vivo ACLT canine model using combined PET/CT and MRI demonstrated to be highly sensitive in the detection of metabolic alterations in osseous and nonosteochondral structures comprising the knee joint. 18F-fluoro-d-glucose appeared to be a capable potential imaging biomarker for early human knee OA diagnosis, prognosis, and management.

The diagnostic value of MRI and gadolinium-DTPA compared with CT for the diagnosis of bladder tumours

International Nuclear Information System (INIS)

Nicolas, V.; Spielmann, R.; Maas, R.; Buecheler, E.; Wagner, B.; Bressel, M.; Porst, H.

1990-01-01

In a prospective study, 58 patients with carcinomas of the bladder were examined by CT and MRI; in 48, gadolinium-DTPA was administered intravenously. MRI provided exact staging in 89%, compared with 80% with CT. There was 13% over-staging with CT and 11% with MRI. MRI, unlike CT did not result in any under-staging. In 36 patients a quotient could be calculated from the signal intensity of the tumour and surrounding soft tissues both before and after the intravenous contrast medium and the increased quotient after contrast administration could be estimated. There was a significant increase in the tumour/muscle quotient with a mean of 72±22% (minimum 43%, maximum 153%), corresponding to a marked increase of the signal form the tumour when compared with the precontrast images. This had the following advantages compared with CT: Accurate differentiation between superficial and intramural spread. MRI was better than CT at demonstrating tumours in the roof of the bladder and at the trigone. (orig.) [de

Improved detection of localized prostate cancer using co-registered MRI and {sup 11}C-acetate PET/CT

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Jambor, Ivan, E-mail: ivjamb@utu.fi [Department of Diagnostic Radiology, University of Turku, Turku (Finland); 2nd Department of Radiology, Comenius University and St. Elisabeth Oncology Institute, Bratislava (Slovakia); Turku PET Centre, University of Turku, Turku (Finland); Borra, Ronald, E-mail: ronald.borra@tyks.fi [Department of Diagnostic Radiology, University of Turku, Turku (Finland); Turku PET Centre, University of Turku, Turku (Finland); Medical Imaging Centre of Southwest Finland, Turku University Hospital, Turku (Finland); Kemppainen, Jukka, E-mail: Jukka.Kemppainen@tyks.fi [Turku PET Centre, University of Turku, Turku (Finland); Department of Clinical Physiology and Nuclear Medicine, Turku University Hospital, Turku (Finland); Lepomaeki, Virva, E-mail: Virva.Lepomaki@tyks.fi [Turku PET Centre, University of Turku, Turku (Finland); Parkkola, Riitta, E-mail: Riitta.Parkkola@tyks.fi [Department of Diagnostic Radiology, University of Turku, Turku (Finland); Turku PET Centre, University of Turku, Turku (Finland); Medical Imaging Centre of Southwest Finland, Turku University Hospital, Turku (Finland); Dean, Kirsti, E-mail: Kirsti.Dean@tyks.fi [Department of Diagnostic Radiology, University of Turku, Turku (Finland); Medical Imaging Centre of Southwest Finland, Turku University Hospital, Turku (Finland); Alanen, Kalle, E-mail: Kalle.Alanen@tyks.fi [Department of Pathology, Turku University Hospital, Turku (Finland); Arponen, Eveliina, E-mail: Eveliina.Arponen@utu.fi [Turku PET Centre, University of Turku, Turku (Finland); Nurmi, Martti, E-mail: Martti.Nurmi@tyks.fi [Department of Surgery, Division of Urology, Turku University Hospital, Turku (Finland); Aronen, Hannu J., E-mail: Hannu.Aronen@tyks.fi [Department of Diagnostic Radiology, University of Turku, Turku (Finland); Medical Imaging Centre of Southwest Finland, Turku University Hospital, Turku (Finland); and others

2012-11-15

Objectives: We aimed to study the ability of contrast enhanced MRI at 1.5 T and {sup 11}C-acetate PET/CT, both individually and using fused data, to detect localized prostate cancer. Methods: Thirty-six men with untreated prostate cancer and negative for metastatic disease on pelvic CT and bone scan were prospectively enrolled. A pelvic {sup 11}C-acetate PET/CT scan was performed in all patients, and a contrast enhanced MRI scan in 33 patients (6 examinations using both endorectal coil and surface coils, and 27 examinations using surface coils only). After the imaging studies 10 patients underwent prostatectomy and 26 were treated by image guided external beam radiation treatment. Image fusion of co-registered PET and MRI data was performed based on anatomical landmarks visible on CT and MRI using an advanced in-house developed software package. PET/CT, MRI and fused PET/MRI data were evaluated visually and compared with biopsy findings on a lobar level, while a sextant approach was used for patients undergoing prostatectomy. Results: When using biopsy samples as method of reference, the sensitivity, specificity and accuracy for visual detection of prostate cancer on a lobar level by contrast enhanced MRI was 85%, 37%, 73% and that of {sup 11}C-acetate PET/CT 88%, 41%, 74%, respectively. Fusion of PET with MRI data increased sensitivity, specificity and accuracy to 90%, 72% and 85%, respectively. Conclusions: Fusion of sequentially obtained PET/CT and MRI data for the localization of prostate cancer is feasible and superior to the performance of each individual modality alone.

Grading of Crohn's disease activity using CT, MRI, US and scintigraphy: a meta-analysis

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Puylaert, C.A.J.; Tielbeek, J.A.W.; Bipat, S.; Stoker, J. [University of Amsterdam, Academic Medical Center, Department of Radiology, Amsterdam (Netherlands)

2015-11-15

To assess the grading of Crohn's disease activity using CT, MRI, US and scintigraphy. MEDLINE, EMBASE and Cochrane databases were searched (January 1983-March 2014) for studies evaluating CT, MRI, US and scintigraphy in grading Crohn's disease activity compared to endoscopy, biopsies or intraoperative findings. Two independent reviewers assessed the data. Three-by-three tables (none, mild, frank disease) were constructed for all studies, and estimates of accurate, over- and under-grading were calculated/summarized by fixed or random effects models. Our search yielded 9356 articles, 19 of which were included. Per-patient data showed accurate grading values for CT, MRI, US and scintigraphy of 86 % (95 % CI: 75-93 %), 84 % (95 % CI: 67-93 %), 44 % (95 % CI: 28-61 %) and 40 % (95 % CI: 16-70 %), respectively. In the per-patient analysis, CT and MRI showed similar accurate grading estimates (P = 0.8). Per-segment data showed accurate grading values for CT and scintigraphy of 87 % (95 % CI: 77-93 %) and 86 % (95 % CI: 80-91 %), respectively. MRI and US showed grading accuracies of 67-82 % and 56-75 %, respectively. CT and MRI showed comparable high accurate grading estimates in the per-patient analysis. Results for US and scintigraphy were inconsistent, and limited data were available. (orig.)

Cortical laminar necrosis in brain infarcts: serial MRI

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Siskas, N.; Lefkopoulos, A.; Ioannidis, I.; Charitandi, A.; Dimitriadis, A.S. [Radiology Department, AHEPA University Hospital, Aristotele University of Thessaloniki (Greece)

2003-05-01

High-signal cortical lesions are observed on T1-weighted images in cases of brain infarct. Histological examination has demonstrated these to be ''cortical laminar necrosis'', without haemorrhage or calcification. We report serial MRI in this condition in 12 patients with brain infarcts. We looked at high-signal lesions on T1-weighted images, chronological changes in signal intensity and contrast enhancement. High-signal cortical lesions began to appear about 2 weeks after the ictus, were prominent at 1 - 2 months, then became less evident, but occasionally remained for up to 1.5 years. They gave high signal or were isointense on T2-weighted images and did not give low signal at any stage. Contrast enhancement of these lesions was prominent at 1 - 2 months, and less apparent from 3 months, but was seen up to 5 months. (orig.)

Clinical assessment of CT-MRI image fusion software in localization of the prostate for 3D conformal radiation therapy

International Nuclear Information System (INIS)

Kagawa, Kazufumi; Lee, W. Robert; Schultheiss, Timothy E.; Hunt, Margie A.; Shaer, Andrew H.; Hanks, Gerald E.

1996-01-01

Purpose: To assess the utility of image fusion software and compare MRI prostate localization with CT localization in patients undergoing 3D conformal radiation therapy of prostate cancer. Materials and Methods: After a phantom study was performed to ensure the accuracy of image fusion procedure, 22 prostate cancer patients had CT and MRI studies before the start of radiotherapy. Immobilization casts used during radiation treatment were also used for both imaging studies. After the clinical target volume (CTV) (prostate or prostate + seminal vesicles) was defined on CT, slices from MRI study were reconstructed to match precisely the corresponding CT slices by identifying three common bony landmarks on each study. The CTV was separately defined on the matched MRI slices. Data related to the size and location of the prostate were compared between CT and MRI. The spatial relationship between the tip of urethrogram cone on CT and prostate apex seen on MRI was also scrutinized. Results: The phantom study showed the registration discrepancies between CT and MRI smaller than 1.0 mm in any pair of comparison. The patient study showed mean image registration error of 0.9 (± 0.6) mm. The average prostate volume was 63.0 (± 25.8) cm 3 and 50.9 (± 22.9) cm 3 determined by CT and MRI respectively (Fig. 1). The difference in prostate location with the two studies most commonly differed at the base and at the apex of the prostate (Fig. 2). On transverse MRI, the prostate apex was situated 7.1 (± 4.5) mm dorsal and 15.1 (± 4.0) mm cephalad to the tip of urethrogram cone (Fig. 3). Conclusions: CT-MRI image fusion study made it possible to compare the two modalities directly. MRI localization of the prostate is more accurate than CT, and indicates the distance from cone to apex is 15 mm. In view of excellent treatment results obtained with current CT localization of the prostate, still it may not be wise to reduce target volume to that demonstrated on MRI

Differential diagnosis of truly suprasellar space-occupying masses: synopsis of clinical findings, CT, and MRI

International Nuclear Information System (INIS)

Reul, J.; Weis, J.; Spetzger, U.; Isensee, C.; Thron, A.

1995-01-01

This review demonstrates the features of truly suprasellar masses in modern imaging based on the clinical, CT, and MRI findings of 42 patients with suprasellar masses in correlation to the histologic findings. The radiologic examinations were evaluated retrospectively to determine if diagnosis can be made based on specific imaging patterns. The most frequent clinical findings of space-occupying suprasellar masses were visual disturbances, diabetes insipidus, and symptoms and signs of occlusive hydrocephalus. There were no clinical features specific for any of the observed masses. Craniopharyngiomas were the most frequent tumors. They appeared in two different forms, as cystic and as solid enhancing masses. The cystic tumors could not be differentiated from cystic hamartomas or cystic gliomas by CT or MRI. The solid craniopharyngiomas were similar to meningiomas and hamartomas. In craniopharyngiomas of adults calcifications were not common. In CT and especially in MRI gliomas were characterized by the diffuse infiltration of the adjacent brain tissue or optic nerve. Except for meningiomas, all lesions were highly variable in appearance, making a reliable characterization by CT and MRI difficult in many cases. However, administration of contrast media in some cases resulted in a better tumor delineation. Compared with unenhanced MRI the enhanced scans did not increase diagnostic efficacy for neoplasms, but were helpful in the differentiation from inflammatory diseases. The MRI technique was superior to CT in demonstrating the anatomic relationships, thus facilitating evaluation of origin and extent of the lesions. The CT technique, of course, was more reliable in the detection of calcifications. Both CT and MRI are not tissue-specific, however, and suprasellar tumors as well as many other neoplasms cannot be classified using only one of these imaging techniques. (orig.)

Pancreatic gross tumor volume contouring on computed tomography (CT) compared with magnetic resonance imaging (MRI): Results of an international contouring conference.

Science.gov (United States)

Hall, William A; Heerkens, Hanne D; Paulson, Eric S; Meijer, Gert J; Kotte, Alexis N; Knechtges, Paul; Parikh, Parag J; Bassetti, Michael F; Lee, Percy; Aitken, Katharine L; Palta, Manisha; Myrehaug, Sten; Koay, Eugene J; Portelance, Lorraine; Ben-Josef, Edgar; Erickson, Beth A

Accurate identification of the gross tumor volume (GTV) in pancreatic adenocarcinoma is challenging. We sought to understand differences in GTV delineation using pancreatic computed tomography (CT) compared with magnetic resonance imaging (MRI). Twelve attending radiation oncologists were convened for an international contouring symposium. All participants had a clinical and research interest in pancreatic adenocarcinoma. CT and MRI scans from 3 pancreatic cases were used for contouring. CT and MRI GTVs were analyzed and compared. Interobserver variability was compared using Dice's similarity coefficient (DSC), Hausdorff distances, and Jaccard indices. Mann-Whitney tests were used to check for significant differences. Consensus contours on CT and MRI scans and constructed count maps were used to visualize the agreement. Agreement regarding the optimal method to determine GTV definition using MRI was reached. Six contour sets (3 from CT and 3 from MRI) were obtained and compared for each observer, totaling 72 contour sets. The mean volume of contours on CT was significantly larger at 57.48 mL compared with a mean of 45.76 mL on MRI, P = .011. The standard deviation obtained from the CT contours was significantly larger than the standard deviation from the MRI contours (P = .027). The mean DSC was 0.73 for the CT and 0.72 for the MRI (P = .889). The conformity index measurement was similar for CT and MRI (P = .58). Count maps were created to highlight differences in the contours from CT and MRI. Using MRI as a primary image set to define a pancreatic adenocarcinoma GTV resulted in smaller contours compared with CT. No differences in DSC or the conformity index were seen between MRI and CT. A stepwise method is recommended as an approach to contour a pancreatic GTV using MRI. Copyright © 2017 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

Differences in MRI findings in cases showing ring-enhancement on a CT scan

International Nuclear Information System (INIS)

Tokiwa, Kaichi; Hashimoto, Takashi; Miyasaka, Yoshio; Yada, Kenzoh; Kan, Shinichi; Takagi, Hiroshi.

1990-01-01

It is sometimes difficult to differentiate between a brain abscess and a tumor, for both show ring-enhancement on a CT scan. The present authors have studied the benefit of MRI for the differential diagnosis of these two lesions. The subjects of this study were 6 cases of brain abscess and 10 cases of brain tumor, all of them showing ring-enhancement on a CT scan. The MRI findings were compared with those of the CT scan taken at almost the same time, especially focussing on the difference in the ring-enhancement. In 5 out of the 6 cases of brain abscess, T 2 -weighted MRI demonstrated a comparatively thin and homogeneous low-intensity, round rim. In the cases of brain tumor, however, none of the cases demonstrated this typical low-intensity, round rim; rather, in them the rim was thick and irregular. The authors can conclude that those MRI findings can serve as important differential diagnostic findings between brain abscess and tumor; also, MRI may be used as a landmark for terminating the administration of antibiotics in cases of brain abscess. (author)

The registration accuracy analysis of different CT-MRI imaging fusion method in brain tumor

International Nuclear Information System (INIS)

Lu Jie; Yin Yong; Shao Qian; Zhang Zicheng; Chen Jinhu; Chen Zhaoqiu

2010-01-01

Objective: To find an effective CT-MRI image fusion protocol in brain tumor by analyzing the registration accuracy of different methods. Methods: The simulation CT scan and MRI T 1 WI imaging of 10 brain tumor patients obtained with same position were registered by Tris-Axes landmark ,Tris-Axes landmark + manual adjustment, mutual information and mutual information + manual adjustment method. The clinical tumor volume (CTV) were contoured on both CT and MRI images respectively. The accuracy of image fusion was assessed by the mean distance of five bone markers (d 1-5 ), central position of CTV (d CTV ) the percentage of CTV overlap (P CT-MRI ) between CT and MRI images. The difference between different methods was analyzed by Freedman M non-parameter test. Results: The difference of the means d1-5 between the Tris-Axes landmark,Tris-Axes landmark plus manual adjustment,mutual information and mutual information plus manual adjustment methods were 0.28 cm ±0.12 cm, 0.15 cm ±0.02 cm, 0.25 cm± 0.19 cm, 0.10 cm ± 0.06 cm, (M = 14.41, P = 0.002). the means d CTV were 0.59 cm ± 0.28 cm, 0.60 cm± 0.32 cm, 0.58 cm ± 0.39 cm, 0.42 cm± 0.30 cm (M = 9.72, P = 0.021), the means P CT-MRI were 0.69% ±0.18%, 0.68% ±0.16%, 0.66% ±0.17%, 0.74% ±0.14% (M =14.82, P=0.002), respectively. Conclusions: Mutual information plus manual adjustment registration method was the preferable fusion method for brain tumor patients. (authors)

Comparison of Ct and MRI in the study of the pituitary gland

International Nuclear Information System (INIS)

Juliani, G.; Avataneo, T.; Potenzoni, F.; Sorrentino, T

1989-01-01

Normal CT and MR anatomy was studied in two series (53 and 25 cases respectively) of young volunteers of both sexes, asymptomatic and certainly without lesions of the pituitary gland. 115 other pathological cases (73 hyperprolactinemias, 8 acromegalies, 15 Cushing syndromes, 2 hyperthyroidisms, 17 non-secreting adenomas) were examined using both CT and MRI. Both an accurate review of the relative literature and the results of our own series prove that MR is superior to CT in diagnosing pituitary microadenomas (3.2% not diagnosed with MRI and 25.8% not diagnosed with CT), in the follow-up of prolactinomas subjected to medical therapy and in the study of extrasellar involvement of pituitery adenomas, particularly with regard to the demonstration of compression of the optic chiasma

Imaging features of primary Sarcomas of the great vessels in CT, MRI and PET/CT: a single-center experience

International Nuclear Information System (INIS)

Falck, Christian von; Meyer, Bernhard; Fegbeutel, Christine; Länger, Florian; Bengel, Frank; Wacker, Frank; Rodt, Thomas

2013-01-01

To investigate the imaging features of primary sarcomas of the great vessels in CT, MRI and 18 F-FDG PET/CT. Thirteen patients with a primary sarcoma of the great vessels were retrospectively evaluated. All available images studies including F-18 FDG PET(/CT) (n = 4), MDCT (n = 12) and MRI (n = 6) were evaluated and indicative image features of this rare tumor entity were identified. The median interval between the first imaging study and the final diagnosis was 11 weeks (0–12 weeks). The most frequently observed imaging findings suggestive of malignant disease in patients with sarcomas of the pulmonary arteries were a large filling defect with vascular distension, unilaterality and a lack of improvement despite effective anticoagulation. In patients with aortic sarcomas we most frequently observed a pedunculated appearance and an atypical location of the filling defect. The F-18 FDG PET(/CT) examinations demonstrated an unequivocal hypermetabolism of the lesion in all cases (4/4). MRI proved lesion vascularization in 5/6 cases. Intravascular unilateral or atypically located filling defects of the great vessels with vascular distension, a pedunculated shape and lack of improvement despite effective anticoagulation are suspicious for primary sarcoma on MDCT or MRI. MR perfusion techniques can add information on the nature of the lesion but the findings may be subtle and equivocal. F-18 FDG PET/CT may have a potential role in these patients and may be considered as part of the imaging workup

Value of fusion of PET and MRI for staging of endometrial cancer: Comparison with {sup 18}F-FDG contrast-enhanced PET/CT and dynamic contrast-enhanced pelvic MRI

Energy Technology Data Exchange (ETDEWEB)

Kitajima, Kazuhiro, E-mail: kitajima@med.kobe-u.ac.jp [Department of Radiology, Kobe University School of Medicine, Kobe (Japan); Suenaga, Yuko; Ueno, Yoshiko [Department of Radiology, Kobe University School of Medicine, Kobe (Japan); Kanda, Tomonori [Department of Obsterics and Gynecology of Kobe University School of Medicine, Kobe (Japan); Department of Radiology, Hyogo Cancer Center, Hyogo (Japan); Maeda, Tetsuo; Takahashi, Satoru [Department of Radiology, Kobe University School of Medicine, Kobe (Japan); Ebina, Yasuhiko; Miyahara, Yoshiya; Yamada, Hideto [Department of Obsterics and Gynecology of Kobe University School of Medicine, Kobe (Japan); Department of Radiology, Hyogo Cancer Center, Hyogo (Japan); Sugimura, Kazuro [Department of Radiology, Kobe University School of Medicine, Kobe (Japan)

2013-10-01

Purpose: To investigate the diagnostic value of retrospective fusion of pelvic MRI and {sup 18}F-fluorodeoxyglucose ({sup 18}F-FDG) PET images for assessment of locoregional extension and nodal staging of endometrial cancer. Materials and methods: Thirty patients with biopsy-proven endometrial cancer underwent preoperative contrast-enhanced PET/CT (PET/ceCT) and pelvic dynamic contrast-enhanced MRI for initial staging. Diagnostic performance of PET/ceCT, contrast-enhanced MRI, and retrospective image fusion from PET and MRI (fused PET/MRI) for assessing the extent of the primary tumor (T stage) and metastasis to regional LNs (N stage) was evaluated by two experienced readers. Histopathological and follow-up imaging results were used as the gold standard. The McNemar test was employed for statistical analysis. Results: Fused PET/MRI and MRI detected 96.7% of the primary tumors, whereas PET/ceCT detected 93.3%. Accuracy for T status was 80.0% for fused PET/MRI, and MRI proved significantly more accurate than PET/ceCT, which had an accuracy of 60.0% (p = 0.041). Patient-based sensitivity, specificity and accuracy for detecting pelvic nodal metastasis were 100%, 96.3% and 96.7% for both fused PET/MRI and PET/ceCT, and 66.7%, 100% and 96.7% for MRI, respectively. These three parameters were not statistically significant (p = 1). Conclusion: Fused PET/MRI, which complements the individual advantages of MRI and PET, is a valuable technique for assessment of the primary tumor and nodal staging in patients with endometrial cancer.

Diagnosing and staging of cystic echinococcosis: how do CT and MRI perform in comparison to ultrasound?

Directory of Open Access Journals (Sweden)

Marija Stojkovic

Full Text Available BACKGROUND: Imaging plays the key role in diagnosing and staging of CE. The description of CE-specific imaging features and the WHO CE cyst classification is based on ultrasound. The reproducibility of the ultrasound-defined features of CE cysts is variable in MR- and CT-imaging. This is of particular importance for cysts that are not accessible by US and because of the increasing availability and overuse of CT and MR imaging. METHODOLOGY/PRINCIPAL FINDINGS: Retrospective analysis of patients with abdominal CE cysts of an interdisciplinary CE clinic who had CT and/or MRI scans performed additionally to US imaging. All images were read and interpreted by the same senior radiologist experienced in the diagnosis of CE. US, CT and MR images were staged according to the WHO classification criteria. The agreement beyond chance was quantified by kappa coefficients (κ. 107 patients with 187 CE cysts met the inclusion criteria. All cysts were assessed by US, 138 by CT, and 125 by MRI. The level of agreement beyond chance of the individual CE stages 1-4 was clearly lower for CT, with κ ranging from 0.62 to 0.72, compared to MRI with values of κ between 0.83 and 1.0. For CE5 cysts CT (κ = 0.95 performed better than MRI (κ = 0.65. CONCLUSIONS: Ultrasound remains the corner stone of diagnosis, staging and follow up of CE cysts. MRI reproduces the ultrasound-defined features of CE better than CT. If US cannot be performed due to cyst location or patient-specific reasons MRI with heavily T2-weighted series is preferable to CT.

Value of fusion of PET and MRI in the detection of intra-pelvic recurrence of gynecological tumor: comparison with 18F-FDG contrast-enhanced PET/CT and pelvic MRI.

Science.gov (United States)

Kitajima, Kazuhiro; Suenaga, Yuko; Ueno, Yoshiko; Kanda, Tomonori; Maeda, Tetsuo; Makihara, Natsuko; Ebina, Yasuhiko; Yamada, Hideto; Takahashi, Satoru; Sugimura, Kazuro

2014-01-01

To evaluate the diagnostic value of retrospective image fusion from pelvic magnetic resonance imaging (MRI) and 18F-fluorodeoxyglucose positron emission tomography (PET) in detecting intra-pelvic recurrence of gynecological tumor. Thirty patients with a suspicion of recurrence of gynecological malignancy underwent inline contrast-enhanced PET/computed tomography (CT) and pelvic contrast-enhanced MRI for restaging. Diagnostic performance about the local recurrence, pelvic lymph node and bone metastasis and peritoneal lesion of PET/low-dose non-enhanced CT (PET/ldCT), PET/full-dose contrast-enhanced CT (PET/ceCT), contrast-enhanced MRI, and retrospective image fusion from PET and MRI (fused PET/MRI) were evaluated by two experienced readers. Final diagnoses were obtained by histopathological examinations, radiological imaging and clinical follow-up for at least 6 months. McNemar test was employed for statistical analysis. Documented positive locally recurrent disease, pelvic lymph node and bone metastases, and peritoneal dissemination were present in 53.3, 26.7, 10.0, and 16.7%, respectively. Patient-based sensitivity for detecting local recurrence, pelvic lymph node and bone metastasis and peritoneal lesion were 87.5, 87.5, 100 and 80.0%, respectively, for fused PET/MRI, 87.5, 62.5, 66.7 and 60.0%, respectively, for contrast-enhanced MRI, 62.5, 87.5, 66.7 and 80.0%, respectively, for PET/ceCT, and 50.0, 87.5, 66.7 and 60.0%, respectively, for PET/ldCT. The sensitivity of diagnosing local recurrence by fused PET/MRI was significantly better than that of PET/ldCT (p=0.041). The patient-based sensitivity, specificity and accuracy for the detection of intra-pelvic recurrence/metastasis were 91.3, 100 and 93.3% for fused PET/MRI, 82.6, 100 and 86.7% for contrast-enhanced MRI, 82.6, 100 and 86.7% for PET/ceCT and 78.3, 85.7 and 80.0% for PET/ldCT. Fused PET/MRI combines the individual advantages of MRI and PET, and is a valuable technique for assessment of intra

Cranial CT and MRI in malignant phenylketonuria

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Gudinchet, F.; Maeder, P.; Meuli, R.A. (CHUV, Lausanne (Switzerland). Dept. of Radiology); Deonna, T.; Mathieu, J.M. (CHUV, Lausanne (Switzerland). Dept. of Pediatrics)

1992-06-01

Malignant phenylketonuria is a rare disease caused by a deficiency in dihydropteridine-reductase which induce a hyperphenylalaninemia and a defiency of neurotransmitters such as 3,4, dihydroxyphenylalanine (DOPA) and 5 hydroxytriphtophan. The case of a patient with malignant phenylketonuria (PKU) who underwent both CT and MR Imaging is reported. CT demonstrated the characteristic calcifications of the basal ganglia. MRI demonstrated areas of hypersignal on T1 and images in the basal ganglia, subcortical frontal and occipital white matter and cortex probably corresponding to clacifications. The MR findings are not specific but could be useful in monitoring the diet and neurotransmitter substitution therapy. (orig.).

Cranial CT and MRI in malignant phenylketonuria

International Nuclear Information System (INIS)

Gudinchet, F.; Maeder, P.; Meuli, R.A.; Deonna, T.; Mathieu, J.M.

1992-01-01

Malignant phenylketonuria is a rare disease caused by a deficiency in dihydropteridine-reductase which induce a hyperphenylalaninemia and a defiency of neurotransmitters such as 3,4, dihydroxyphenylalanine (DOPA) and 5 hydroxytriphtophan. The case of a patient with malignant phenylketonuria (PKU) who underwent both CT and MR Imaging is reported. CT demonstrated the characteristic calcifications of the basal ganglia. MRI demonstrated areas of hypersignal on T1 and images in the basal ganglia, subcortical frontal and occipital white matter and cortex probably corresponding to clacifications. The MR findings are not specific but could be useful in monitoring the diet and neurotransmitter substitution therapy. (orig.)

The diagnostic value of 18F-FDG-PET/CT and MRI in suspected vertebral osteomyelitis - a prospective study.

Science.gov (United States)

Kouijzer, Ilse J E; Scheper, Henk; de Rooy, Jacky W J; Bloem, Johan L; Janssen, Marcel J R; van den Hoven, Leon; Hosman, Allard J F; Visser, Leo G; Oyen, Wim J G; Bleeker-Rovers, Chantal P; de Geus-Oei, Lioe-Fee

2018-05-01

The aim of this study was to determine the diagnostic value of 18 F-fluorodeoxyglucose (FDG) positron emission tomography and computed tomography (PET/CT) and magnetic resonance imaging (MRI) in diagnosing vertebral osteomyelitis. From November 2015 until December 2016, 32 patients with suspected vertebral osteomyelitis were prospectively included. All patients underwent both 18 F-FDG-PET/CT and MRI within 48 h. All images were independently reevaluated by two radiologists and two nuclear medicine physicians who were blinded to each others' image interpretation. 18 F-FDG-PET/CT and MRI were compared to the clinical diagnosis according to international guidelines. For 18 F-FDG-PET/CT, sensitivity, specificity, PPV, and NPV in diagnosing vertebral osteomyelitis were 100%, 83.3%, 90.9%, and 100%, respectively. For MRI, sensitivity, specificity, PPV, and NPV were 100%, 91.7%, 95.2%, and 100%, respectively. MRI detected more epidural/spinal abscesses. An important advantage of 18 F-FDG-PET/CT is the detection of metastatic infection (16 patients, 50.0%). 18 F-FDG-PET/CT and MRI are both necessary techniques in diagnosing vertebral osteomyelitis. An important advantage of 18 F-FDG-PET/CT is the visualization of metastatic infection, especially in patients with bacteremia. MRI is more sensitive in detection of small epidural abscesses.

Imaging diagnostics of the wrist: MRI and Arthrography/Arthro-CT; Bildgebende Diagnostik des Handgelenkes: MRT und Arthrographie/Arthro-CT

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Klein, H.M.; Balas, R.; Neugebauer, F. [Radiologische Gemeinschaftspraxis, Betzdorf (Germany); Vrsalovic, V. [Handchirugie, Marienhospital Siegen, Siegen (Germany)

2002-02-01

Purpose: To evaluate the use of magnetic resonance imaging (MRI) compared with arthrography and arthro-CT (AG/ACT) in patients with wrist pain. Methods: MRI and arthrography/arthro-CT (AG/ACT) of the wrist joint were retrospectively evaluated in 346 patients over a three-year period. Imaging findings were correlated to surgical results (n=78) or clinical course in an at least 6-month follow-up. Results: For tears of the triangular fibrocartilage, arthrography, arthro-CT, and MRI demonstrated a sensitivity and specificity of more than 0.96. Only the positive predictive value was superior for arthrography/arthro-CT (0.99 and 0.98, respectively) compared with MRI (0.94). Arthrography was superior for functional diagnosis of scapho-lunate ligament tears (n=25). Ulno-lunate and ulno-triquetral ligament defects were demonstrated more exactly by arthrography. Traumatic osseous defects, particularly scaphoid fractures (n=33) and avascular necrosis (n=17), were better diagnosed using MRI. Conclusion: For suspected lesions of the triangular fibrocartilage complex, AG/ACT is slightly more reliable than MRI. However, MRI was found to be highly accurate in diagnosing TFC tears, and is superior to AG/ACT in detecting traumatic and vascular lesions of the wrist. (orig.) [German] Ziel: Die Untersuchung der diagnostischen Aussagekraft von Magnetresonanz-Tomographie (MRT), Arthrographie (AG) und Arthro-CT (ACT) bei Erkrankungen des Handgelenkes. Methodik: Insgesamt 346 Untersuchungen des Handgelenkes wurden fuer einen dreijaehrigen Beobachtungszeitraum retrospektiv ausgewertet. Es wurden 211 MRT, 151 Arthrographien (AG) und 126 Arthro-CT (ACT) durchgefuehrt. Alle Diagnosen wurden operativ (n=78) oder durch den klinischen Verlauf in einer 6-monatigen Nachbeobachtung gesichert. Ergebnisse: Fuer die Diagnostik von Laesionen des diskoulnaren Komplexes lag die Sensitivitaet und Spezifitaet von AG, ACT und MRT ueber 0,96. Lediglich der positive Vorhersagewert differierte, allerdings nicht

Conspicuity of FDG-aid osseous lesions on PET/MRI versus PET/CT: A quantitative and visual analysis

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Fraum, Tyler J.; Fowler, Kathryn J.; Mcconathy, Jonathan [Mallinckrodt Institute of Radiology, Washington University School of Medicine, Saint Louis (United States)

2016-09-15

Because standard MRI-based attenuation correction (AC) does not account for the attenuation of photons by cortical bone, PET/MRI may have reduced sensitivity for FDG-avid focal bone lesions (FFBLs). This study evaluates whether MRI-based AC compromises detection of FFBLs, by comparing their conspicuity both quantitatively and qualitatively on PET/MRI versus PET/CT. One hundred ninety general oncology patients underwent whole-body PET/CT followed by whole-body PET/MRI, utilizing the same FDG dose. Thirteen patients with a total of 50 FFBLs were identified. Using automated contouring software, a volumetric contour was generated for each FFBL. Adjacent regions of normal background bone (BB) were selected manually. For each contour, SUV-max and SUV-mean were determined. Lesion-to-background SUV ratios served as quantitative metrics of conspicuity. Additionally, two blinded readers evaluated the relative conspicuity of FFBLs on PET images derived from MRI-based AC versus CT-based AC. Visibility of an anatomic correlate for FFBLs on the corresponding CT and MR images was also assessed. SUV-mean was lower on PET/MRI for both FFBLs (-6.5 %, p = 0.009) and BB (-20.5 %, p < 0.001). SUV-max was lower on PET/MRI for BB (-14.2 %, p = 0.002) but not for FFBLs (-6.2 %, p = 0.068). The ratio of FFBL SUV-mean to BB SUV-mean was higher for PET/MRI (+29.5 %, p < 0.001). Forty of 50 lesions (80 %) were visually deemed to be of equal or greater conspicuity on PET images derived from PET/MRI. Thirty-five of 50 FFBLs (70 %) had CT correlates, while 40/50 FFBLs (80 %) had a correlate on at least one MRI sequence. The mean interval from tracer administration to imaging was longer (p < 0.001) for PET/MRI (127 v. 62 min). Both FFBLs and BB had lower mean SUVs on PET/MRI than PET/CT. This finding was likely in part due to differences in the handling of cortical bone by MRI-based AC versus CT-based AC. Despite this systematic bias, FFBLs had greater conspicuity on PET/MRI

Comparison of MRI, CT, TCD and SPECT in patients with spongiform leukoencephalopathy after inhaling heroin vapor

International Nuclear Information System (INIS)

Wang Qun; Lu Bingxun; Yuan Huijuan

2002-01-01

Objective: To compare the characteristics of MRI, CT, single photon emission computed tomography (SPECT) and transcranial Doppler sonography (TCD) in patients with spongiform leukoencephalopathy after inhaling heroin vapor. Methods: Seventeen patients were investigated. MRI or CT was scanned in 17 patients, SPECT in 9 patients' and TCD in 11 patients. Results: MRI or CT: Brain MRI and CT revealed extensive symmetric white matter involvement of bilateral cerebral and cerebellar hemispheres and the brainstem. The lesions, which showed no contrast enhancement, were hypodense on CT and hypointense on T 1 -weighted and hyperintense on T 2 -weighted MRI. SPECT: The regional cerebral blood flows (rCBF) of white matter involvement on bilateral cerebral and cerebellar hemispheres was reduced obviously. The rCBF of temporal lobes, parietal lobes, occipital lobes, cerebellar hemispheres, and basal ganglion was reduced in varying degrees. TCD: The systolic peak became sharpened, and end-diastolic flow velocity and mean flow velocity were reduced obviously and pulsatile index was increased markedly in patients with spongiform leukoencephalopathy after inhaling heroin vapor. Conclusion: The characteristic manifestations of MRI and CT imaging may be regarded as the main foundation of diagnosing spongiform leukoencephalopathy after inhaling heroin vapor; SPECT and TCD can help comprehend the changes of hemodynamics of cerebral vessels and the degree of cerebral ischemia in patients with spongiform leukoencephalopathy after inhaling heroin vapor

Initial clinical assessment of CT-MRI image fusion software in localization of the prostate for 3D conformal radiation therapy

International Nuclear Information System (INIS)

Kagawa, Kazufumi; Lee, W. Robert; Schultheiss, Timothy E.; Hunt, Margie A.; Shaer, Andrew H.; Hanks, Gerald E.

1997-01-01

Purpose: To assess the utility of image fusion software and compare MRI prostate localization with CT localization in patients undergoing 3D conformal radiation therapy of prostate cancer. Materials and Methods: After a phantom study was performed to ensure the accuracy of image fusion procedure, 22 prostate cancer patients had CT and MRI studies before the start of radiotherapy. Immobilization casts used during radiation treatment were also used for both imaging studies. After the clinical target volume (CTV) (prostate or prostate + seminal vesicles) was defined on CT, slices from the MRI study were reconstructed to precisely match the CT slices by identifying three common bony landmarks on each study. The CTV was separately defined on the matched MRI slices. Data related to the size and location of the prostate were compared between CT and MRI. The spatial relationship between the tip of urethrogram cone on CT and prostate apex seen on MRI was also estimated. Results: The phantom study showed the registration discrepancies between CT and MRI smaller than 1.0 mm in any pair in comparison. The patient study showed a mean image registration error of 0.9 (± 0.6) mm. The average prostate volume was 63.0 (± 25.8) cm 3 and 50.9 (± 22.9) cm 3 determined by CT and MRI, respectively. The difference in prostate location with the two studies usually differed at the base and at the apex of the prostate. On the transverse MRI, the prostate apex was situated 7.1 (± 4.5) mm dorsal and 15.1 (± 4.0) mm cephalad to the tip of urethrogram cone. Conclusions: CT-MRI image fusion study made it possible to compare the two modalities directly. MRI localization of the prostate is more accurate than CT, and indicates the distance from cone to apex is 15 mm. CT-MRI image fusion technique provides valuable supplements to CT technology for more precise targeting of the prostate cancer

Prospective evaluation of {sup 18}F-FACBC PET/CT and PET/MRI versus multiparametric MRI in intermediate- to high-risk prostate cancer patients (FLUCIPRO trial)

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Jambor, Ivan [University of Turku, Department of Diagnostic Radiology, Turku (Finland); University of Massachusetts Medical School - Baystate, Department of Radiology, Springfield, MA (United States); Turku PET Centre, Turku (Finland); Kuisma, Anna [Turku University Hospital, Department of Oncology and Radiotherapy, Turku (Finland); Kaehkoenen, Esa; Bostroem, Peter J. [Turku University Hospital, Department of Urology, Turku (Finland); Kemppainen, Jukka [Turku PET Centre, Turku (Finland); Turku University Hospital, Department of Clinical Physiology and Nuclear Medicine, Turku (Finland); Merisaari, Harri [University of Turku, Department of Diagnostic Radiology, Turku (Finland); Turku PET Centre, Turku (Finland); University of Turku, Department of Information Technology, Turku (Finland); Eskola, Olli; Teuho, Jarmo [Turku PET Centre, Turku (Finland); Montoya Perez, Ileana [University of Turku, Department of Diagnostic Radiology, Turku (Finland); University of Turku, Department of Information Technology, Turku (Finland); Turku University Hospital, Medical Imaging Centre of Southwest Finland, Turku (Finland); Pesola, Marko [University of Turku, Department of Diagnostic Radiology, Turku (Finland); Aronen, Hannu J. [University of Turku, Department of Diagnostic Radiology, Turku (Finland); Turku University Hospital, Medical Imaging Centre of Southwest Finland, Turku (Finland); Taimen, Pekka [University of Turku and Turku University Hospital, Department of Pathology, Turku (Finland); Minn, Heikki [Turku PET Centre, Turku (Finland); Turku University Hospital, Department of Oncology and Radiotherapy, Turku (Finland)

2018-03-15

The purpose of this study was to evaluate {sup 18}F-FACBC PET/CT, PET/MRI, and multiparametric MRI (mpMRI) in detection of primary prostate cancer (PCa). Twenty-six men with histologically confirmed PCa underwent PET/CT immediately after injection of 369 ± 10 MBq {sup 18}F-FACBC (fluciclovine) followed by PET/MRI started 55 ± 7 min from injection. Maximum standardized uptake values (SUV{sub max}) were measured for both hybrid PET acquisitions. A separate mpMRI was acquired within a week of the PET scans. Logan plots were used to calculate volume of distribution (V{sub T}). The presence of PCa was estimated in 12 regions with radical prostatectomy findings as ground truth. For each imaging modality, area under the curve (AUC) for detection of PCa was determined to predict diagnostic performance. The clinical trial registration number is NCT02002455. In the visual analysis, 164/312 (53%) regions contained PCa, and 41 tumor foci were identified. PET/CT demonstrated the highest sensitivity at 87% while its specificity was low at 56%. The AUC of both PET/MRI and mpMRI significantly (p < 0.01) outperformed that of PET/CT while no differences were detected between PET/MRI and mpMRI. SUV{sub max} and V{sub T} of Gleason score (GS) >3 + 4 tumors were significantly (p < 0.05) higher than those for GS 3 + 3 and benign hyperplasia. A total of 442 lymph nodes were evaluable for staging, and PET/CT and PET/MRI demonstrated true-positive findings in only 1/7 patients with metastatic lymph nodes. Quantitative {sup 18}F-FACBC imaging significantly correlated with GS but failed to outperform MRI in lesion detection. {sup 18}F-FACBC may assist in targeted biopsies in the setting of hybrid imaging with MRI. (orig.)

Comparison of MRI and PET-CT in detecting the loco-regional recurrence of soft tissue sarcomas during surveillance

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Park, Sun-Young [University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology and Research Institute of Radiology, 88, Olympic-ro 43-gil, Songpa-gu, Seoul (Korea, Republic of); Hallym University Sacred Heart Hospital, Department of Radiology, Anyang-si, Gyeonggi-do (Korea, Republic of); Chung, Hye Won [University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology and Research Institute of Radiology, 88, Olympic-ro 43-gil, Songpa-gu, Seoul (Korea, Republic of); Chae, Sun Young [University of Ulsan College of Medicine, Asan Medical Center, Department of Nuclear Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul (Korea, Republic of); Lee, Jong-Seok [University of Ulsan College of Medicine, Asan Medical Center, Department of Orthopedic Surgery, 88, Olympic-ro 43-gil, Songpa-gu, Seoul (Korea, Republic of)

2016-10-15

To investigate the diagnostic performance of MRI and PET-CT for the detection of loco-regional recurrences after soft tissue sarcoma (STS) excision. From Dec 2003 to Aug 2014, 394 patients with STSs, who were included in the electronic patient registry for initial or repeated surgery at our hospital, were retrospectively reviewed. We identified 152 patients who underwent regular postoperative follow-ups with both MRI and PET-CT, obtained within a 3 month period of each other. We analyzed differences in the performance of MRI and PET-CT for the diagnosis of loco-regional recurrences using McNemar's test. The receiver-operating characteristic curves and calculations of the area under the curve were used. Twenty patients were found to have a loco-regional recurrence after tumor excision. For MRI and PET-CT, the sensitivities were 90.0 and 95.0 %, and the specificities 97.7 and 95.5 %, respectively, with positive predictive values of 85.7 and 76.0 % and negative predictive values of 98.5 and 99.2 %, respectively. No significant difference was detected between the sensitivities of MRI and PET-CT (p = 0.125). The area under the receiver-operating characteristic curve for PET-CT (0.952) was not significantly greater than that for MRI (0.939; p = 0.6). MRI of the area of interest is recommended for evaluation of tumor recurrence after surgical excision of STS. PET-CT was shown to be effective for detection of STS recurrence, and comparable to MRI. However, if PET-CT or MRI findings are inconclusive, the other modality may be helpful in differentiating tumor recurrence from post-therapeutic tissue change. (orig.)

Lumbar apophyseal ring fracture and disc herniation: CT and MRI manifestations

International Nuclear Information System (INIS)

Lee, Hyeon Kyeong; Kang, Heung Sik; Song, Chi Sung

1991-01-01

To understand CT and MR findings and, furthermore, the pathophysiology of the lumbar apophyseal ring fracture (LARF) associated with lumbar disc herniation in 31 cases of LARF (CT was performed in 23, MRI in 18, and both CT and MRI in 12), we studied the age and sex distribution of the patients, history of trauma, shape of bony fragment, number of lesions, lesion sites, associated lumbar disc herniations, and evidence of Scheuermann's disease. Twenty-three out of 31 patients were male, 6 were adolescents, 21 were young adults, and 4 were middled-aged. Arcuate or nodular bone fragment and/or bone defects were detected at the posterior margin of L1 in 2, L2 in 1, L3 in 1, L4 in 10, L5 in 20 and S1 in 7 patients. Eight patients showed multiple LARF, and 13 showed multiple lumbar disc herniations. Radiologic evidence of Scheuermann's disease was obvious in 9 patients. Only 6 patients had a history of evident trauma. CT and MRI showed a similar detection rate of bone fragments and defects. We concluded that LARF would be encountered in young male patients with multiple lumbar disc herniations and evidence of Scheuermann's disease

Serial automated quantitative CT analysis in idiopathic pulmonary fibrosis. Functional correlations and comparison with changes in visual CT scores

International Nuclear Information System (INIS)

Jacob, Joseph; Bartholmai, Brian J.; Rajagopalan, Srinivasan; Kokosi, Maria; Wells, Athol U.; Egashira, Ryoko; Brun, Anne Laure; Nair, Arjun; Walsh, Simon L.F.; Karwoski, Ronald

2018-01-01

To determine whether computer-based CT quantitation of change can improve on visual change quantification of parenchymal features in IPF. Sixty-six IPF patients with serial CT imaging (6-24 months apart) had CT features scored visually and with a computer software tool: ground glass opacity, reticulation and honeycombing (all three variables summed as interstitial lung disease extent [ILD]) and emphysema. Pulmonary vessel volume (PVV) was estimated by computer only. Relationships between changes in CT features and forced vital capacity (FVC) were examined using univariate and multivariate linear regression analyses. On univariate analysis, changes in computer variables demonstrated stronger linkages to FVC change than changes in visual scores (CALIPER ILD:R 2 =0.53, p<0.0001; Visual ILD:R 2 =0.16, p=0.001). PVV increase correlated most strongly with relative FVC change (R 2 =0.57). When PVV constituents (vessel size and location) were examined, an increase in middle zone vessels linked most strongly to FVC decline (R 2 =0.57) and was independent of baseline disease severity (characterised by CT fibrosis extent, FVC, or DLco). An increase in PVV, specifically an increase in middle zone lung vessels, was the strongest CT determinant of FVC decline in IPF and was independent of baseline disease severity. (orig.)

Serial automated quantitative CT analysis in idiopathic pulmonary fibrosis. Functional correlations and comparison with changes in visual CT scores

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Jacob, Joseph; Bartholmai, Brian J.; Rajagopalan, Srinivasan [Mayo Clinic Rochester, Division of Radiology, Rochester, MN (United States); Kokosi, Maria; Wells, Athol U. [Royal Brompton and Harefield NHS Foundation Trust, Interstitial Lung Disease Unit, Royal Brompton Hospital, London (United Kingdom); Egashira, Ryoko [Saga Daigaku, Department of Radiology, Saga (Japan); Brun, Anne Laure [Whittington Hospital, Department of Radiology, London (United Kingdom); Nair, Arjun [Guys and St Thomas' NHS Foundation Trust, Department of Radiology, London (United Kingdom); Walsh, Simon L.F. [Kings College Hospital NHS Foundation Trust, Department of Radiology, London (United Kingdom); Karwoski, Ronald [Mayo Clinic Rochester, Department of Physiology and Biomedical Engineering, Rochester, MN (United States)

2018-03-15

To determine whether computer-based CT quantitation of change can improve on visual change quantification of parenchymal features in IPF. Sixty-six IPF patients with serial CT imaging (6-24 months apart) had CT features scored visually and with a computer software tool: ground glass opacity, reticulation and honeycombing (all three variables summed as interstitial lung disease extent [ILD]) and emphysema. Pulmonary vessel volume (PVV) was estimated by computer only. Relationships between changes in CT features and forced vital capacity (FVC) were examined using univariate and multivariate linear regression analyses. On univariate analysis, changes in computer variables demonstrated stronger linkages to FVC change than changes in visual scores (CALIPER ILD:R{sup 2}=0.53, p<0.0001; Visual ILD:R{sup 2}=0.16, p=0.001). PVV increase correlated most strongly with relative FVC change (R{sup 2}=0.57). When PVV constituents (vessel size and location) were examined, an increase in middle zone vessels linked most strongly to FVC decline (R{sup 2}=0.57) and was independent of baseline disease severity (characterised by CT fibrosis extent, FVC, or DLco). An increase in PVV, specifically an increase in middle zone lung vessels, was the strongest CT determinant of FVC decline in IPF and was independent of baseline disease severity. (orig.)

CT and MRI findings of 4th ventricular tumors

International Nuclear Information System (INIS)

Kim, Taek Geun; Ro, Hee Jeong; Byun, Jae Young; Lee, Han Jin; Chung, Myung Hee; Choi, Kyu Ho; Shinn, Kyung Sub

1994-01-01

The purpose of our study is to evaluate characteristic features of 4th ventricular tumors in CT and MRI. Pathologically proved 9 patients with 4th ventricular tumor were examined by CT and/or MRI. 4th ventricular tumors were ependymoma(4 cases), medulloblastoma(2 case), choroid plexus papilloma(2 cases), and oligodendroglioma(1 cases). Include in our study were only those mass lesions that were located at surgery predominantly within 4th ventricle with or without ventricular expansion. The origin of 4th ventricular tumor was the roof (ependymoma 3 cases, medulloblastoma 2 cases), the floor (ependymoma 1 cases), and the undetermined(remaining 3 case). On MRI, all tumors were hypointense except ependymoma (3 cases) showing isointensity on T1WI. All tumors were hypointense on PDWI and T2WI. On Gd-DTPA enhanced T1WI, strong enhancement was seen in all but ependymoma(1 cases) which showed mild enhancement. On CT, as compared with MR images, various density on precontrast and postcontrast images were seen. Calcification was seen in choroid plexus papilloma(1 caes) and oligodendroglioma(1 cases). Hydrocephalus is seen in all cases except ependymoma(2 cases) and oligodendroglioma(1 case). Hemorrhage within tumor was present only in ependymoma(2 cases). Cystic change or necrosis of tumor was seen in ependymoma(3 cases), choroid plexus papilloma(1 case), and oligodendroglioma(1 case). Peritumoral edema was seen in medulloblastoma(1 case). Extension through the foramen Luschka and the Megendie was seen in ependymoma (2 cases), choroid plexus(2 cases), and medulloblastoma (1 case). Seeing along the CSF pathway was seen only in ependymoma(2 case). The results od our study may suggest that specific diagnosis of 4th ventricular tumor can be suggested preoperatively by analysing the origin in 4th ventricle, difference of CT density or MRI signal intensity, presence of extension or seeding through cerebrospinal fluid of the lesion

Fully automated deformable registration of breast DCE-MRI and PET/CT

Science.gov (United States)

Dmitriev, I. D.; Loo, C. E.; Vogel, W. V.; Pengel, K. E.; Gilhuijs, K. G. A.

2013-02-01

Accurate characterization of breast tumors is important for the appropriate selection of therapy and monitoring of the response. For this purpose breast imaging and tissue biopsy are important aspects. In this study, a fully automated method for deformable registration of DCE-MRI and PET/CT of the breast is presented. The registration is performed using the CT component of the PET/CT and the pre-contrast T1-weighted non-fat suppressed MRI. Comparable patient setup protocols were used during the MRI and PET examinations in order to avoid having to make assumptions of biomedical properties of the breast during and after the application of chemotherapy. The registration uses a multi-resolution approach to speed up the process and to minimize the probability of converging to local minima. The validation was performed on 140 breasts (70 patients). From a total number of registration cases, 94.2% of the breasts were aligned within 4.0 mm accuracy (1 PET voxel). Fused information may be beneficial to obtain representative biopsy samples, which in turn will benefit the treatment of the patient.

SPECT/CT versus MRI in patients with nonspecific pain of the hand and wrist - a pilot study

International Nuclear Information System (INIS)

Huellner, Martin W.; Buerkert, Alexander; Schleich, Florian S.; Strobel, Klaus; Veit-Haibach, Patrick; Schuerch, Maja; Hug, Urs; Wartburg, Urs von

2012-01-01

Hand and wrist pain is a diagnostic challenge for hand surgeons and radiologists due to the complex anatomy of the involved small structures. The American College of Radiology recommends MRI as the study of choice in patients with chronic wrist pain if radiographs are negative. Lately, state-of-the-art SPECT/CT systems have been introduced and may help in the diagnosis of this selected indication. This retrospective study included 21 patients with nonspecific pain of the hand/wrist. The diagnosis of nonspecific wrist pain was made by the referring hand surgeon based on patient history, clinical examination, plain radiography and clinical guidelines. All patients received planar early-phase imaging and late-phase SPECT/CT imaging as well as MRI. Lesions were divided into major (causative) and minor (not causative) pathologies according to clinical follow-up. Furthermore, oedema-like bone marrow changes seen on MRI were compared with focally increased tracer uptake seen on SPECT/CT images. MRI yielded a quite high sensitivity (0.86), but a low specificity (0.20). In contrast, SPECT/CT yielded a high specificity (1.00) and a low sensitivity (0.71). Oedema-like bone marrow changes were detected in 15 lesions in 11 patients. In ten lesions with bone marrow oedema on MRI, foci of elevated tracer uptake were detected on SPECT/CT. Overall, MRI was more sensitive, but SPECT/CT was more specific in the evaluation of causative pathologies. In this initial comparison, SPECT/CT showed higher specificity than MRI in the evaluation of causative pathologies in patients with nonspecific wrist pain. However, MRI was more sensitive. Thus, SPECT/CT was shown to be a useful problem-solving tool in the diagnostic work-up of these patients. (orig.)

Serial micro-CT assessment of the therapeutic effects of rosiglitazone in a bleomycin-induced lung fibrosis mouse model

Energy Technology Data Exchange (ETDEWEB)

Choi, Eun Jung; Jin, Gong Yong; Bok, Se Mi; Han, Young Min; Lee, Young Sun; Jung, Myung Ja; Kwon, Keun Sang [Research Institute of Clinical Medicine of Chonbuk National University, Biomedical Research Institute of Chonbuk National University Hospital, Institute for Medical Sciences, Jeonju (Korea, Republic of)

2014-08-15

The aim of this study was to assess the therapeutic effects of rosiglitazone with serial micro-CT findings before and after rosiglitazone administration in a lung fibrosis mouse model induced with bleomycin. We instilled the bleomycin solution directly into the trachea in twenty mice (female, C57BL/6 mice). After the instillation with bleomycin, mice were closely observed for 3 weeks and then all mice were scanned using micro-CT without sacrifice. At 3 weeks, the mice were treated with rosiglitazone on days 21 to 27 if they had abnormal CT findings (n = 9, 45%). For the mice treated with rosiglitazone, we performed micro-CT with mouse sacrifice 2 weeks after the rosiglitazone treatment completion. We assessed the abnormal CT findings (ground glass attenuation, consolidation, bronchiectasis, reticular opacity, and honeycombing) using a five-point scale at 3 and 6 weeks using Wilcoxon-signed ranked test. The micro-CT findings were correlated with the histopathologic results. One out of nine (11.1%) mice improved completely. In terms of consolidation, all mice (100%) showed marked decrease from 3.1 ± 1.4 at 3 weeks to 0.9 ± 0.9 at 6 weeks (p = 0.006). At 6 weeks, mild bronchiectasis (n = 6, 66.7%), mild reticular opacity (n 7, 77.8%) and mild honeycomb patterns (n = 3, 33.3%) appeared. A serial micro-CT enables the evaluation of drug effects in a lung fibrosis mouse model.

Brain CT and MRI findings of a long-term case of subacute sclerosing panencephalitis

Energy Technology Data Exchange (ETDEWEB)

Aoshiba, Kazunori; Ota, Kohei; Komatsuzaki, Satoshi; Kobayashi, Itsuro; Maruyama, Shoichi

1987-11-01

Our study involved a long-term case (ten years) of subacute sclerosing panencephalitis. The case began with a 23 year-old experiencing visual deterioration. During the course of his illness, amnesia, autism and abnormal behavior were observed without any myoclonus. On the electroencephalogram, periodic synclonous discharge was shown in the early stage of his illness and subsequently disappeared. The brain CT and the MRI disclosed diffuse lesions in both cortical and subcortical areas of the cerebral hemispheres. The location and spread of lesions were more clearly revealed by the MRI than the brain CT. These findings suggest that the MRI is more useful than the brain CT in the diagnosis of subacute sclerosing panencephalitis.

Brain CT and MRI findings of a long-term case of subacute sclerosing panencephalitis

International Nuclear Information System (INIS)

Aoshiba, Kazunori; Ota, Kohei; Komatsuzaki, Satoshi; Kobayashi, Itsuro; Maruyama, Shoichi

1987-01-01

Our study involved a long-term case (ten years) of subacute sclerosing panencephalitis. The case began with a 23 year-old experiencing visual deterioration. During the course of his illness, amnesia, autism and abnormal behavior were observed without any myoclonus. On the electroencephalogram, periodic synclonous discharge was shown in the early stage of his illness and subsequently disappeared. The brain CT and the MRI disclosed diffuse lesions in both cortical and subcortical areas of the cerebral hemispheres. The location and spread of lesions were more clearly revealed by the MRI than the brain CT. These findings suggest that the MRI is more useful than the brain CT in the diagnosis of subacute sclerosing panencephalitis. (author)

Muscle atrophy and metal-on-metal hip implants: a serial MRI study of 74 hips.

Science.gov (United States)

Berber, Reshid; Khoo, Michael; Cook, Erica; Guppy, Andrew; Hua, Jia; Miles, Jonathan; Carrington, Richard; Skinner, John; Hart, Alister

2015-06-01

Muscle atrophy is seen in patients with metal-on-metal (MOM) hip implants, probably because of inflammatory destruction of the musculo-tendon junction. However, like pseudotumors, it is unclear when atrophy occurs and whether it progresses with time. Our objective was to determine whether muscle atrophy associated with MOM hip implants progresses with time. We retrospectively reviewed 74 hips in 56 patients (32 of them women) using serial MRI. Median age was 59 (23-83) years. The median time post-implantation was 83 (35-142) months, and the median interval between scans was 11 months. Hip muscles were scored using the Pfirrmann system. The mean scores for muscle atrophy were compared between the first and second MRI scans. Blood cobalt and chromium concentrations were determined. The median blood cobalt was 6.84 (0.24-90) ppb and median chromium level was 4.42 (0.20-45) ppb. The median Oxford hip score was 34 (5-48). The change in the gluteus minimus mean atrophy score between first and second MRI was 0.12 (p = 0.002). Mean change in the gluteus medius posterior portion (unaffected by surgical approach) was 0.08 (p = 0.01) and mean change in the inferior portion was 0.10 (p = 0.05). Mean pseudotumor grade increased by 0.18 (p = 0.02). Worsening muscle atrophy and worsening pseudotumor grade occur over a 1-year period in a substantial proportion of patients with MOM hip implants. Serial MRI helps to identify those patients who are at risk of developing worsening soft-tissue pathology. These patients should be considered for revision surgery before irreversible muscle destruction occurs.

Contrast-enhanced CT and MRI findings of atypical hepatic Echinococcus alveolarisinfestation

International Nuclear Information System (INIS)

Etlik, Oemer; Arslan, Halil; Harman, Mustafa; Temizoez, Osman; Bay, Ali; Koesem, Mustafa; Dogan, Ekrem

2005-01-01

Diagnosis of liver infestation by Echinococcus alveolaris(EA) is based on serological and radiological findings. In this report, we present a 15-year-old girl with atypical hepatic EA infestation showing central punctate calcifications and contrast enhancement on the portal and late phases of CT and MRI. CT showed a hypodense mass involving more than half of the liver with prominent central calcifications. MRI revealed hypointense signal of the infiltrative mass on both T1- and T2-weighted images. Contrast enhancement is a unique finding in hepatic EA infestation that may cause difficulties with diagnosis. MRI may provide invaluable information in the diagnosis of EA infestation of the liver, either by disclosing the infiltrative pattern of infestation without significant effect to vascular structures, or by the signal characteristics. (orig.)

Contrast-enhanced CT and MRI findings of atypical hepatic Echinococcus alveolarisinfestation

Energy Technology Data Exchange (ETDEWEB)

Etlik, Oemer; Arslan, Halil; Harman, Mustafa; Temizoez, Osman [Yuzuncu Yil University Faculty of Medicine, Department of Radiology, Van (Turkey); Bay, Ali [Yuzuncu Yil University Faculty of Medicine, Department of Paediatrics, Van (Turkey); Koesem, Mustafa [Yuzuncu Yil University Faculty of Medicine, Department of Pathology, Van (Turkey); Dogan, Ekrem [Yuzuncu Yil University Faculty of Medicine, Department of Internal Medicine, Van (Turkey)

2005-05-01

Diagnosis of liver infestation by Echinococcus alveolaris(EA) is based on serological and radiological findings. In this report, we present a 15-year-old girl with atypical hepatic EA infestation showing central punctate calcifications and contrast enhancement on the portal and late phases of CT and MRI. CT showed a hypodense mass involving more than half of the liver with prominent central calcifications. MRI revealed hypointense signal of the infiltrative mass on both T1- and T2-weighted images. Contrast enhancement is a unique finding in hepatic EA infestation that may cause difficulties with diagnosis. MRI may provide invaluable information in the diagnosis of EA infestation of the liver, either by disclosing the infiltrative pattern of infestation without significant effect to vascular structures, or by the signal characteristics. (orig.)

CT of the musculoskeletal system: What is left is the days of MRI?

International Nuclear Information System (INIS)

West, A.T.H.; Marshall, T.J.; Bearcroft, P.W.

2009-01-01

Magnetic resonance imaging (MRI) plays a central role in the modern imaging of musculoskeletal disorders, due to its ability to produce multiplanar images and characterise soft tissues accurately. However, computed tomography (CT) still has an important role to play, not merely as an alternative to MRI, but as being the preferred imaging investigation in some situations. This article briefly reviews the history of CT technology, the technical factors involved and a number of current applications, as well as looking at future areas where CT may be employed. The advent of ever-increasing numbers of rows of detectors has opened up more possible uses for CT technology. However, diagnostic images may be obtained from CT systems with four rows of detectors or more, and their ability to produce near isotropic voxels and therefore multiplanar reformats. (orig.)

SU-E-J-218: Novel Validation Paradigm of MRI to CT Deformation of Prostate

Energy Technology Data Exchange (ETDEWEB)

Padgett, K [University of Miami School of Medicine - Radiation Oncology, Miami, FL (United States); University of Miami School of Medicine - Radiology, Miami, FL (United States); Pirozzi, S; Nelson, A; Piper, J; Horvat, M [MIM Software Inc., Cleveland, OH (United States); Stoyanova, R; Dogan, N; Pollack, A [University of Miami School of Medicine - Radiation Oncology, Miami, FL (United States)

2015-06-15

Purpose: Deformable registration algorithms are inherently difficult to characterize in the multi-modality setting due to a significant differences in the characteristics of the different modalities (CT and MRI) as well as tissue deformations. We present a unique paradigm where this is overcome by utilizing a planning-MRI acquired within an hour of the planning-CT serving as a surrogate for quantifying MRI to CT deformation by eliminating the issues of multi-modality comparisons. Methods: For nine subjects, T2 fast-spin-echo images were acquired at two different time points, the first several weeks prior to planning (diagnostic-MRI) and the second on the same day as the planning-CT (planning-MRI). Significant effort in patient positioning and bowel/bladder preparation was undertaken to minimize distortion of the prostate in all datasets. The diagnostic-MRI was rigidly and deformably aligned to the planning-CT utilizing a commercially available deformable registration algorithm synthesized from local registrations. Additionally, the quality of rigid alignment was ranked by an imaging physicist. The distances between corresponding anatomical landmarks on rigid and deformed registrations (diagnostic-MR to planning-CT) were evaluated. Results: It was discovered that in cases where the rigid registration was of acceptable quality the deformable registration didn’t improve the alignment, this was true of all metrics employed. If the analysis is separated into cases where the rigid alignment was ranked as unacceptable the deformable registration significantly improved the alignment, 4.62mm residual error in landmarks as compared to 5.72mm residual error in rigid alignments with a p-value of 0.0008. Conclusion: This paradigm provides an ideal testing ground for MR to CT deformable registration algorithms by allowing for inter-modality comparisons of multi-modality registrations. Consistent positioning, bowel and bladder preparation may Result in higher quality rigid

CT and MRI features of acinar cell carcinoma of the pancreas with pathological correlations

International Nuclear Information System (INIS)

Hsu, M.-Y.; Pan, K.-T.; Chu, S.-Y.; Hung, C.-F.; Wu, R.-C.; Tseng, J.-H.

2010-01-01

Aim: To document the computed tomography (CT) and magnetic resonance imaging (MRI) features of acinar cell carcinoma of the pancreas and to correlate them with pathological findings to determine the unique imaging manifestations of this rare subtype tumour of the pancreas. Materials and methods: From January 1986 to August 2008, six patients (five men and one woman, mean age 61.3 years) with histologically proven acinar cell carcinoma of the pancreas underwent CT (n = 6) and MRI (n = 4) examinations. The imaging features of each tumour were documented and compared with pathological findings. Results: The tumours were distributed in the head (n = 4), body (n = 1), and tail (n = 1) of the pancreas. Four masses (67%) were uniformly or partially well-defined with thin, enhancing capsules. Central cystic components were found in five tumours (83%). Two tumours (33%) exhibited intratumoural haemorrhage, and one tumour (17%) had amorphous intratumoural calcification. In both CT and MRI, the tumours enhanced less than the adjacent normal pancreatic parenchyma. The signal intensity on MRI was predominantly T1 hypointense and T2 iso- to hyperintense. Conclusion: Acinar cell carcinoma of the pancreas has distinct imaging features, and both CT and MRI are useful and complementary imaging methods.

Comparative study of radiography, CT and MRI in the identification of hip involvement in patients with ankylosing spondylitis

International Nuclear Information System (INIS)

Huang Zhenguo; Zhang Xuezhe; Hu Libin; Wang Guochun; Zhou Huiqiong; Lu Xin; Wang Wu

2012-01-01

Objective: To study the imaging findings of hip involvement and to compare the sensitivity of radiography, CT, and MRI in the identification of hip involvement in patients with ankylosing spondylitis (AS). Methods: Anteroposterior radiography of the pelvis and MRI of hip were performed in 55 patients with AS. CT scan of hip was performed in 29 of 55 patients. T 1 -weighted, T 2 -weighted, short tau inversion recovery (STIR) and three dimensional balanced turbo field echo with water selective excitation (3D-BTFE-WATS) coronal sequences of hips were obtained in all patients, of which fat-saturated contrast-enhanced T 1 -weighted sequence was performed in 24 patients. The imaging data of 55 patients were analyzed. The chi-square test was used to analyze the sensitivity in the identification of hip involvement among radiography, CT, and MRI. Results: Among 110 hips in all 55 patients, abnormal changes were detected in 13 hips by radiography, 85 hips by MRI. The findings of radiography included bone erosions in 13 hips, joint space narrowing in 4 hips,syndesmophytes in 5 hips. MRI revealed bone erosive destruction in 31 hips, joint space narrowing in 4 hips, joint effusion in 80 hips, subchondral bone marrow edema in 32 hips, fat accumulation of bone marrow in 28 hips, enthesitis in 21 hips. Bilateral synovial enhancement was showed in 19 of 24 patients who underwent fat-saturated contrast-enhanced T 1 -weighted sequence. Of the 58 hip joints in 29 patients who underwent CT examination, not only did CT show all bone erosions detected by radiography and MRI, but CT revealed bone erosive destruction that were not identified by radiography in 10 hips and by MRI in 1 hip as well. Abnormal changes were detected in 10.3% (6/58)by radiography, 27.6% (16/58) by CT, and 77.6% (45/58) by MRI. The sensitivity of MRI in the identification of hip involvement is higher than that of radiography and CT (χ 2 =53.22 and 29.08, P<0.05). In addition to chronic bone structural changes, MRI

CT and MRI of the liver: when, what, why?; CT und MRT der Leber: wann, was, warum

Energy Technology Data Exchange (ETDEWEB)

Budjan, J.; Schoenberg, S.O.; Attenberger, U.I. [Medizinische Fakultaet Mannheim der Universitaet Heidelberg, Institut fuer Klinische Radiologie und Nuklearmedizin, Universitaetsmedizin Mannheim, Mannheim (Germany)

2017-05-15

The detection and differential diagnostic clarification of liver pathologies play an important role in almost all medical disciplines. Because of its superior soft tissue contrast, the availability of liver-specific contrast agents and functional techniques, magnetic resonance imaging (MRI) is the method of choice for the diagnostics of focal and diffuse liver pathologies. In addition to its superior detection and differentiation capabilities, MRI can provide prognostic information and enable early assessment of the therapy response for malignant liver lesions using functional techniques, especially diffusion imaging. Computed tomography (CT) is the imaging method of choice for the detection of traumatic liver injury. Despite the increasing availability of functional techniques in CT, MRI remains the overall modality of choice in liver imaging. (orig.) [German] Die Detektion und die differenzialdiagnostische Abklaerung von Leberpathologien spielen in nahezu allen medizinischen Disziplinen eine bedeutende Rolle. Ihre Vorteile in Hinblick auf Weichteilkontrast, die Verfuegbarkeit leberspezifischer Kontrastmittel und funktionelle Techniken machen die MRT zum bildgebenden Verfahren der Wahl fuer die gezielte Abklaerung fokaler oder diffuser Leberpathologien. Neben hoeheren Detektionsraten und besseren Differenzierungsmoeglichkeiten stehen in der MRT funktionelle Techniken - insbesondere die Diffusionsbildgebung - zur Verfuegung, die eine Prognoseabschaetzung und die fruehe Beurteilung von Therapieansprechen bei malignen Leberlaesionen erlauben. Die CT ist bei der Detektion traumatischer Leberverletzungen Bildgebungsverfahren der Wahl; trotz der auch in der CT zunehmend verfuegbaren funktionellen Techniken bleibt die MRT in der Leberbildgebung weiterhin ueberlegen. (orig.)

A patch-based pseudo-CT approach for MRI-only radiotherapy in the pelvis

DEFF Research Database (Denmark)

Andreasen, Daniel; Van Leemput, Koen; Edmund, Jens M.

2016-01-01

. The authors benchmark the method against a baseline pCT strategy where all voxels inside the body contour are assigned a water-equivalent bulk density. Furthermore, the authors implement a parallelized approximate patch search strategy to speed up the pCT generation time to a more clinically relevant level....... The data consisted of CT and T 1-weighted MRI scans of 10 prostate patients. pCTs were generated using an approximate patch search algorithm in a leave-one-out fashion and compared with the CT using frequently described metrics such as the voxel-wise mean absolute error (MAEvox) and the deviation in water...... showed that a patch-based method based on affine registrations and T 1-weighted MRI could generate accurate pCTs of the pelvis. The main source of differences between pCT and CT was positional changes of air pockets and body outline....

Detection of parenchymal abnormalities in experimentally induced acute pyelonephritis in rabbits using contrast-enhanced ultrasonography, CT, and MRI

Energy Technology Data Exchange (ETDEWEB)

Ryu, Jeong Ah; Kim, Bo Hyun; Kim, Seung Kwon; Seo, Jin Won [Dept. of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Kim, Jong Sung [Laboratory Animal Research Center, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

2016-12-15

We evaluated the efficacy of contrast-enhanced ultrasonography (CEUS) in detecting acute pyelonephritis (APN) using the rabbit kidney model and compared it with CT and MRI. This study was approved by the Institutional Review Board. In a total of 20 New Zealand White rabbits, APN was induced experimentally. CEUS, CT, and MRI were performed on the first, third, and seventh postoperative days. After imaging studies, the subjects were sacrificed and the pathological diagnosis of APN was confirmed in each animal by a pathologist. Imaging studies were obtained in eight animals, including eight CEUS, four computed tomography (CT), and four magnetic resonance imaging (MRI) images. CEUS depicted diffuse renal enlargement (7), diffuse heterogeneous parenchymal enhancement (6), and focal areas of decreased parenchymal enhancement (6). These findings were well correlated with the CT and MRI findings in five cases in which these studies were available. CT and MRI showed diffuse renal enlargement, diffuse heterogeneous parenchymal enhancement, focal areas of decreased parenchymal enhancement, focal contour bulging, and the finding of perinephric spread of infection. In a rabbit model, CEUS could depict the parenchymal lesions of APN similar to CT or MRI; however, it was limited in depicting the perinephric extension of inflammation.

Diagnostic performance of CT and MRI on the detection of symptomatic intracranial dural arteriovenous fistula: a meta-analysis with indirect comparison

Energy Technology Data Exchange (ETDEWEB)

Lin, Yen-Heng [National Taiwan University, Institute of Epidemiology and Preventive Medicine, Taipei (China); National Taiwan University Hospital in Taipei and Yuan-Lin Branch, Department of Medical Imaging and Radiology, Hospital and Medical College, Taipei (China); Lin, Hsien-Ho [National Taiwan University, Institute of Epidemiology and Preventive Medicine, Taipei (China); Liu, Hon-Man; Lee, Chung-Wei; Chen, Ya-Fang [National Taiwan University Hospital in Taipei and Yuan-Lin Branch, Department of Medical Imaging and Radiology, Hospital and Medical College, Taipei (China)

2016-08-15

This study aims to review the diagnostic performance of computed tomography (CT) and magnetic resonance imaging (MRI) in symptomatic dural arteriovenous fistula (DAVF). EMBASE, PubMed, and Cochrane Library were searched until April 2015 for studies which compared CT, MRI, or both with angiography for the detection of DAVF. The diagnostic performances of MRI and CT were indirectly compared using modality as a covariate in the analysis. Thirteen studies met our inclusion criteria. MRI had a sensitivity of 0.90 (95 % confidence interval (CI) = 0.83-0.94) and specificity of 0.94 (95 % CI = 0.90-0.96). CT had a sensitivity of 0.80 (95 % CI = 0.62-0.90) and specificity of 0.87 (95 % CI = 0.74-0.94). MRI showed better diagnostic performance than CT (p = 0.02). Contrast medium use and time-resolved MR angiography did not improve MRI diagnostic performance (p = 0.31 and 0.44, respectively). Both CT and MRI had good diagnostic performance. MRI was better than CT on the detection of symptomatic intracranial dural arteriovenous fistula in the indirect comparison. (orig.)

Comparison between air CT and MRI in the detection of small acoustic neurinomas

Energy Technology Data Exchange (ETDEWEB)

Kamei, Tetsuya; Nakashima, Aiko; Seto, Hikaru; Kakishita, Masao

1989-02-01

Air CT proved useful in yielding images of acoustic tumors as an air filling defect in 11 (24%) of 46 patients. Six of the 11 tumors were small ones of less than 1 cm in diameter. Air CT was also able to exclude an intracanalicular tumor in 29 patients (63%). MRI was performed for comparison in eight patients (nine tumors) already diagnosed by air CT as having an acoustic tumor. MRI detected eight (89%) of nine tumors. A false negative result on MRI was obtained only in one intracanalicular tumor (4.3 mm in size). This was considered to be attributable to limitations of spatial resolution including the wide slice thickness. A protocol for radiological investigation and management of patients whose clinical symptoms and/or audiovestibular examination are highly indicative of acoustic tumor is proposed and discussed. (author).

Comparison between air CT and MRI in the detection of small acoustic neurinomas

International Nuclear Information System (INIS)

Kamei, Tetsuya; Nakashima, Aiko; Seto, Hikaru; Kakishita, Masao

1989-01-01

Air CT proved useful in yielding images of acoustic tumors as an air filling defect in 11 (24%) of 46 patients. Six of the 11 tumors were small ones of less than 1 cm in diameter. Air CT was also able to exclude an intracanalicular tumor in 29 patients (63%). MRI was performed for comparison in eight patients (nine tumors) already diagnosed by air CT as having an acoustic tumor. MRI detected eight (89%) of nine tumors. A false negative result on MRI was obtained only in one intracanalicular tumor (4.3 mm in size). This was considered to be attributable to limitations of spatial resolution including the wide slice thickness. A protocol for radiological investigation and management of patients whose clinical symptoms and/or audiovestibular examination are highly indicative of acoustic tumor is proposed and discussed. (author)

Staging performance of whole-body DWI, PET/CT and PET/MRI in invasive ductal carcinoma of the breast.

Science.gov (United States)

Catalano, Onofrio Antonio; Daye, Dania; Signore, Alberto; Iannace, Carlo; Vangel, Mark; Luongo, Angelo; Catalano, Marco; Filomena, Mazzeo; Mansi, Luigi; Soricelli, Andrea; Salvatore, Marco; Fuin, Niccolo; Catana, Ciprian; Mahmood, Umar; Rosen, Bruce Robert

2017-07-01

The aim of the present study was to evaluate the performance of whole-body diffusion-weighted imaging (WB-DWI), whole-body positron emission tomography with computed tomography (WB-PET/CT), and whole-body positron emission tomography with magnetic resonance imaging (WB-PET/MRI) in staging patients with untreated invasive ductal carcinoma of the breast. Fifty-one women with newly diagnosed invasive ductal carcinoma of the breast underwent WB-DWI, WB-PET/CT and WB-PET/MRI before treatment. A radiologist and a nuclear medicine physician reviewed in consensus the images from the three modalities and searched for occurrence, number and location of metastases. Final staging, according to each technique, was compared. Pathology and imaging follow-up were used as the reference. WB-DWI, WB-PET/CT and WB-PET/MRI correctly and concordantly staged 33/51 patients: stage IIA in 7 patients, stage IIB in 8 patients, stage IIIC in 4 patients and stage IV in 14 patients. WB-DWI, WB-PET/CT and WB-PET/MRI incorrectly and concordantly staged 1/51 patient as stage IV instead of IIIA. Discordant staging was reported in 17/51 patients. WB-PET/MRI resulted in improved staging when compared to WB-PET/CT (50 correctly staged on WB-PET/MRI vs. 38 correctly staged on WB-PET/CT; McNemar's test; p<0.01). Comparing the performance of WB-PET/MRI and WB-DWI (43 correct) did not reveal a statistically significant difference (McNemar test, p=0.14). WB-PET/MRI is more accurate in the initial staging of breast cancer than WB-DWI and WB-PET/CT, however, the discrepancies between WB-PET/MRI and WB-DWI were not statistically significant. When available, WB-PET/MRI should be considered for staging patient with invasive ductal breast carcinoma.

Serial MRI and MRS studies with unusual findings in Rasmussen's encephalitis

Energy Technology Data Exchange (ETDEWEB)

Tuerkdogan-Soezueer, D. [Department of Pediatric Neurology, Institute of Neurological Sciences, Marmara University, Istanbul (Turkey); Oezek, M.M.; Pamir, M.N. [Department of Neurosurgery, Institute of Neurological Sciences, Marmara University, Istanbul (Turkey); Sav, A. [Department of Pathology, Institute of Neurological Sciences, Marmara University, Istanbul (Turkey); Dincer, A. [Radyomar MR Center, Istanbul (Turkey)

2000-06-01

Rasmussen's syndrome is characterized by intractable seizures and progressive neuropsychiatric deterioration secondary to unilateral cortical inflammation and tissue destruction. Diagnosis of Rasmussen's syndrome in the early phase depends mainly on the clinical features. Neuroimaging and histopathologic examinations may not be specific during this period. We report a case of Rasmussen's syndrome followed by serial MRI and magnetic resonance spectroscopy (MRS) studies over a 3- to 16-month period. A healthy 6-year-old boy presented with focal motor seizures. An MRI study demonstrated prominent enlargement and T2 hyperintensity of the left mesial temporal lobe and perisylvian region. This early finding evolved to volume loss and later progressive atrophy of the ipsilateral hemisphere when epilepsia partialis continua occurred. Being aware of those early MRI features in a patient with increasing frequency of focal motor seizures should suggest Rasmussen's syndrome. In addition, we found prominently increased myoinositol concentration in atrophic cortex which might reflect increased gliosis in the late period of the disease. (orig.)

Diagnosis of Chiari III malformation by second trimester fetal MRI with postnatal MRI and CT correlation

International Nuclear Information System (INIS)

Smith, Alice B.; Glenn, Orit A.; Gupta, Nalin; Otto, Carl

2007-01-01

We report a case of Chiari III malformation diagnosed by fetal MRI. Ultrasound (US) performed at a gestational age of 18 weeks demonstrated a posterior skull base cyst. Repeat US at 19 weeks demonstrated neural tissue in the cyst, consistent with an encephalocele. MR imaging at 23 weeks confirmed the presence of an occipital encephalocele, demonstrated additional bony defect in the upper cervical spine, and identified abnormal morphology and position of the brainstem consistent with the diagnosis of Chiari III. Postnatal MRI and CT confirmed the fetal MRI findings and demonstrate the utility of fetal MRI in the early evaluation of songraphically detected posterior fossa abnormalities. (orig.)

Diagnosis of Chiari III malformation by second trimester fetal MRI with postnatal MRI and CT correlation

Energy Technology Data Exchange (ETDEWEB)

Smith, Alice B.; Glenn, Orit A. [University of California, San Francisco, Department of Radiology, San Francisco, CA (United States); Gupta, Nalin [University of California, San Francisco, Department of Neurosurgery, San Francisco, CA (United States); Otto, Carl [California Pacific Medical Center, Department of Perinatology, San Francisco, CA (United States)

2007-10-15

We report a case of Chiari III malformation diagnosed by fetal MRI. Ultrasound (US) performed at a gestational age of 18 weeks demonstrated a posterior skull base cyst. Repeat US at 19 weeks demonstrated neural tissue in the cyst, consistent with an encephalocele. MR imaging at 23 weeks confirmed the presence of an occipital encephalocele, demonstrated additional bony defect in the upper cervical spine, and identified abnormal morphology and position of the brainstem consistent with the diagnosis of Chiari III. Postnatal MRI and CT confirmed the fetal MRI findings and demonstrate the utility of fetal MRI in the early evaluation of songraphically detected posterior fossa abnormalities. (orig.)

18FFDG PET in evaluating malignancies compared with CT, MRI and pathology in 58 cases

International Nuclear Information System (INIS)

Li, L.

2000-01-01

This article discussed the practical application of 18 F-FDG PET imaging techniques to depict, state, or define recurrences for five important malignancies: lung cancer, colorectal and head-and-neck cancer, intracranial malignant glioma and primary or secondary hepatic malignant diseases. And comparisons of 18 F-FDG PET with CT, MRI imaging were addressed specifically. We reviewed our initial experience with 48 malignant and ten non-malignant cases. Among malignant group, 36 cases were confirmed by operation or biopsy, Other ten non-malignant diseases, including brain infarction, post-radiotherapy necrosis or scar and lung abscesses were followed with CT or MRI at least 6 months. All patients received intravenous administration of 18 F-FDG 10-15 mCi, followed by a 40 minutes uptake phase, and subsequent imaged using a Siemens ECAT 931 whole-body scanner with resolution of 4 mm FWHM in the center of the field of view. Filtered back projection reconstruction was used to display attenuated or non-attenuated corrected images. The result of 18 F-FDG PET was retrospectively evaluated to assess the degree of uptake of 18 F-FDG PET in the tumor tissues and compared with CT, MRI and pathology. CT and MRI exam were taken before or after PET study in two weeks. 18 F-FDG PET scans showed a significantly increased FDG metabolism in 47 malignant lesions, The tumor / normal tissue FDG uptake rate were 4.16 ±2.11. In 47 cases with neoplasm, 18 F-FDG PET findings were constant with or further confirmed the CT or MRI diagnosis in 35/47 (74.5%) and 12/47 (253%) cases. Another one small intracranial metastasis ( 18 F-FDG PET imaging in oncology has demonstrated powerful advantage in characterizing tumor lesions, differentiating recurrent disease from treatment effects, staging tumors, evaluating the extent of disease, and monitoring therapy. But 18 F-FDG PET still cant replace CT or MRI in malignance diagnosis. It will be used to approach and hopefully answer the difficult diagnosis

Renal angiomyolipoma without visible fat. Can we make the diagnosis using CT and MRI?

Energy Technology Data Exchange (ETDEWEB)

Lim, Robert S.; McInnes, Matthew D.F.; Schieda, Nicola [The University of Ottawa, Department of Medical Imaging, The Ottawa Hospital, Ottawa, Ontario (Canada); Flood, Trevor A. [The University of Ottawa, Department of Anatomical Pathology, The Ottawa Hospital, Ottawa, Ontario (Canada); Lavallee, Luke T. [The University of Ottawa, Department of Surgery, Division of Urology, The Ottawa Hospital, Ottawa, Ontario (Canada)

2018-02-15

Renal angiomyolipomas without visible fat (AML.wovf) are benign masses that are incidentally discovered mainly in women. AML.wovf are typically homogeneously hyperdense on unenhanced CT without calcification or haemorrhage. Unenhanced CT pixel analysis is not useful for diagnosis. AML.wovf are characteristically homogeneously hypointense on T2-weighted (T2W)-MRI and apparent diffusion coefficient (ADC) maps. Despite early reports, only a minority of AML.wovf show signal intensity drop on chemical-shift MRI due to microscopic fat. AML.wovf most commonly show avid early enhancement with washout kinetics at contrast-enhanced CT and MRI. The combination of homogeneously low T2W and/or ADC signal intensity with avid early enhancement and washout is highly accurate for diagnosis of AML.wovf. (orig.)

A follow-up study by CT and MRI in 3 cases of Japanese encephalitis

International Nuclear Information System (INIS)

Shoji, H.; Murakami, T.; Murai, I.; Kida, H.; Sato, Y.; Kojima, K.; Abe, T.; Okudera, T.

1990-01-01

A follow-up study by CT and MRI in 3 cases of Japanese encephalitis (JE) was performed. Neurologically dementia, forced laughing, tetraplegia and parkinsonism were observed as sequelae. In the CT and MR scans about 3 years after the onset of JE, low-density areas (LDAs) or abnormal signal intensities had remained in the thalamus and basal ganglia. The abnormalities were also found in the brain stem. When the main lesions shown by CT and MRI were compared with those of the acute stage, T2-weighted MRI clearly revealed multiple small areas with high signal intensities, although the ones at the acute stage had showed diffuse abnormal signals. These findings may be useful in helping to identity a long time after the onset. (orig.)

Quantitative Myocardial Perfusion with Dynamic Contrast-Enhanced Imaging in MRI and CT: Theoretical Models and Current Implementation

Directory of Open Access Journals (Sweden)

G. J. Pelgrim

2016-01-01

Full Text Available Technological advances in magnetic resonance imaging (MRI and computed tomography (CT, including higher spatial and temporal resolution, have made the prospect of performing absolute myocardial perfusion quantification possible, previously only achievable with positron emission tomography (PET. This could facilitate integration of myocardial perfusion biomarkers into the current workup for coronary artery disease (CAD, as MRI and CT systems are more widely available than PET scanners. Cardiac PET scanning remains expensive and is restricted by the requirement of a nearby cyclotron. Clinical evidence is needed to demonstrate that MRI and CT have similar accuracy for myocardial perfusion quantification as PET. However, lack of standardization of acquisition protocols and tracer kinetic model selection complicates comparison between different studies and modalities. The aim of this overview is to provide insight into the different tracer kinetic models for quantitative myocardial perfusion analysis and to address typical implementation issues in MRI and CT. We compare different models based on their theoretical derivations and present the respective consequences for MRI and CT acquisition parameters, highlighting the interplay between tracer kinetic modeling and acquisition settings.

Peritoneal mesothelioma: CT and MRI findings

International Nuclear Information System (INIS)

Puvaneswary, M.; Chen, S.; Proietto, T.

2002-01-01

Two patients with histologically proven diagnosis of peritoneal mesothelioma are presented. Both patients had CT scans of the abdomen. The second patient was also examined with MRI. Although imaging findings are striking, they are non-specific and diagnosing peritoneal mesothelioma in the absence of pleural calcification or pleural plaque on chest radiograph or CT is difficult. However, it is possible to suggest the correct diagnosis in a patient with the presence of non-calcified omental and peritoneal infiltration or masses without liver secondaries or lymphadenopathy. Magnetic resonance imaging with its multi-planar capabilities is a highly sensitive non-invasive modality in the evaluation of malignant peritoneal mesothelioma and can demonstrate the exact site and clarify whether the mass is arising from the peritoneal surface or within a visceral organ. Copyright (2002) Blackwell Science Pty Ltd

Value of retrospective image fusion of 18F-FDG PET and MRI for preoperative staging of head and neck cancer: Comparison with PET/CT and contrast-enhanced neck MRI

International Nuclear Information System (INIS)

Kanda, Tomonori; Kitajima, Kazuhiro; Suenaga, Yuko; Konishi, Jyunya; Sasaki, Ryohei; Morimoto, Koichi; Saito, Miki; Otsuki, Naoki; Nibu, Ken-ichi; Sugimura, Kazuro

2013-01-01

Purpose: To assess the clinical value of retrospective image fusion of neck MRI and 18 F-fluorodeoxyglucose ( 18 F-FDG) PET for locoregional extension and nodal staging of neck cancer. Materials and methods: Thirty patients with carcinoma of the oral cavity or hypopharynx underwent PET/CT and contrast-enhanced neck MRI for initial staging before surgery including primary tumor resection and neck dissection. Diagnostic performance of PET/CT, MRI, and retrospective image fusion of PET and MRI (fused PET/MRI) for assessment of the extent of the primary tumor (T stage) and metastasis to regional lymph nodes (N stage) was evaluated. Results: Accuracy for T status was 87% for fused PET/MRI and 90% for MRI, thus proving significantly superior to PET/CT, which had an accuracy of 67% (p = 0.041 and p = 0.023, respectively). Accuracy for N status was 77% for both fused PET/MRI and PET/CT, being superior to MRI, which had an accuracy of 63%, although the difference was not significant (p = 0.13). On a per-level basis, the sensitivity, specificity and accuracy for detection of nodal metastasis were 77%, 96% and 93% for both fused PET/MRI and PET/CT, compared with 49%, 99% and 91% for MRI, respectively. The differences for sensitivity (p = 0.0026) and accuracy (p = 0.041) were significant. Conclusion: Fused PET/MRI combining the individual advantages of MRI and PET is a valuable technique for assessment of staging neck cancer

MRI and CT contrast media extravasation: A systematic review.

Science.gov (United States)

Heshmatzadeh Behzadi, Ashkan; Farooq, Zerwa; Newhouse, Jeffery H; Prince, Martin R

2018-03-01

This systematic review combines data from multiple papers on contrast media extravasation to identify factors contributing to increased extravasation risk. Data were extracted from 17 papers reporting 2191 extravasations in 1,104,872 patients (0.2%) undergoing computed tomography (CT) or magnetic resonance imaging (MRI). Extravasation rates were 0.045% for gadolinium-based contrast agents (GBCA) and nearly 6-fold higher, 0.26% for iodinated contrast agents. Factors associated with increased contrast media extravasations included: older age, female gender, using an existing intravenous (IV) instead of placing a new IV in radiology, in-patient status, use of automated power injection, high injection rates, catheter location, and failing to warm up the more viscous contrast media to body temperature. Contrast media extravasation is infrequent but nearly 6 times less frequent with GBCA for MRI compared with iodinated contrast used in CT.

Comparison of CT and MRI artefacts from coils and vascular plugs used for portal vein embolization

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Geisel, Dominik, E-mail: dominik.geisel@charite.de [Department of Diagnostic and Interventional Radiology, Charité, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin (Germany); Gebauer, Bernhard [Department of Diagnostic and Interventional Radiology, Charité, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin (Germany); Malinowski, Maciej; Stockmann, Martin [Department of General, Visceral and Transplantation Surgery, Charité, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin (Germany); Denecke, Timm [Department of Diagnostic and Interventional Radiology, Charité, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin (Germany)

2014-04-15

Purpose: To retrospectively analyze the degree of artefacts in CT and MRI scans caused by coils and vascular plugs used for portal vein embolization (PVE). Materials and methods: All patients who underwent PVE between July 2011 and December 2012 and received either plug or coil embolization additional to particle embolization were retrospectively analyzed. Artefacts causes by embolization materials were measured in CT and MRI scans following PVE. Results: The sum of the artefact diameters caused from coils was significantly higher in CT (188.3 ± 26.1 mm) than in MRI T1 (50.5 ± 6.5 mm) or T2 imaging (39.5 ± 9.7 mm) (P < 0.05). In MRI, the diameter in T1 and T2 sequences did not differ significantly (P = 0.977). The sum of the artefact diameters from vascular plugs in MRI T1 sequences (62.5 ± 8.7 mm) was significantly higher than in CT (46.6 ± 4.8 mm; P < 0.05) and MRI T2 sequences (52.8 ± 3.8 mm; P < 0.05). Conclusion: PVE with particles and vascular plug causes significantly fewer artefacts than PVE with particles and coils on CT scans following embolization, which can be important in the event of vascular complications or in follow-up scans, should the patient become unresectable.

Evaluation of the PET component of simultaneous [18F]choline PET/MRI in prostate cancer: comparison with [18F]choline PET/CT

International Nuclear Information System (INIS)

Wetter, Axel; Lipponer, Christine; Nensa, Felix; Altenbernd, Jens-Christian; Schlosser, Thomas; Lauenstein, Thomas; Heusch, Philipp; Ruebben, Herbert; Bockisch, Andreas; Poeppel, Thorsten; Nagarajah, James

2014-01-01

The aim of this study was to evaluate the positron emission tomography (PET) component of [ 18 F]choline PET/MRI and compare it with the PET component of [ 18 F]choline PET/CT in patients with histologically proven prostate cancer and suspected recurrent prostate cancer. Thirty-six patients were examined with simultaneous [ 18 F]choline PET/MRI following combined [ 18 F]choline PET/CT. Fifty-eight PET-positive lesions in PET/CT and PET/MRI were evaluated by measuring the maximum and mean standardized uptake values (SUV max and SUV mean ) using volume of interest (VOI) analysis. A scoring system was applied to determine the quality of the PET images of both PET/CT and PET/MRI. Agreement between PET/CT and PET/MRI regarding SUV max and SUV mean was tested using Pearson's product-moment correlation and Bland-Altman analysis. All PET-positive lesions that were visible on PET/CT were also detectable on PET/MRI. The quality of the PET images was comparable in both groups. Median SUV max and SUV mean of all lesions were significantly lower in PET/MRI than in PET/CT (5.2 vs 6.1, p max of PET/CT and PET/MRI (R = 0.86, p mean of PET/CT and PET/MRI (R = 0.81, p max of PET/CT vs PET/MRI and -1.12 to +2.23 between SUV mean of PET/CT vs PET/MRI. PET image quality of PET/MRI was comparable to that of PET/CT. A highly significant correlation between SUV max and SUV mean was found. Both SUV max and SUV mean were significantly lower in [ 18 F]choline PET/MRI than in [ 18 F]choline PET/CT. Differences of SUV max and SUV mean might be caused by different techniques of attenuation correction. Furthermore, differences in biodistribution and biokinetics of [ 18 F]choline between the subsequent examinations and in the respective organ systems have to be taken into account. (orig.)

Functional MRI and CT biomarkers in oncology

Energy Technology Data Exchange (ETDEWEB)

Winfield, J.M. [Institute of Cancer Research and Royal Marsden NHS Foundation Trust, CRUK Imaging Centre at the Institute of Cancer Research, Sutton (United Kingdom); Institute of Cancer Research and Royal Marsden Hospital, MRI Unit, Sutton (United Kingdom); Payne, G.S.; DeSouza, N.M. [Institute of Cancer Research and Royal Marsden NHS Foundation Trust, CRUK Imaging Centre at the Institute of Cancer Research, Sutton (United Kingdom)

2015-04-01

Imaging biomarkers derived from MRI or CT describe functional properties of tumours and normal tissues. They are finding increasing numbers of applications in diagnosis, monitoring of response to treatment and assessment of progression or recurrence. Imaging biomarkers also provide scope for assessment of heterogeneity within and between lesions. A wide variety of functional parameters have been investigated for use as biomarkers in oncology. Some imaging techniques are used routinely in clinical applications while others are currently restricted to clinical trials or preclinical studies. Apparent diffusion coefficient, magnetization transfer ratio and native T{sub 1} relaxation time provide information about structure and organization of tissues. Vascular properties may be described using parameters derived from dynamic contrast-enhanced MRI, dynamic contrast-enhanced CT, transverse relaxation rate (R{sub 2}*), vessel size index and relative blood volume, while magnetic resonance spectroscopy may be used to probe the metabolic profile of tumours. This review describes the mechanisms of contrast underpinning each technique and the technical requirements for robust and reproducible imaging. The current status of each biomarker is described in terms of its validation, qualification and clinical applications, followed by a discussion of the current limitations and future perspectives. (orig.)

Quantification of neonatal lung parenchymal density via ultrashort echo time MRI with comparison to CT.

Science.gov (United States)

Higano, Nara S; Fleck, Robert J; Spielberg, David R; Walkup, Laura L; Hahn, Andrew D; Thomen, Robert P; Merhar, Stephanie L; Kingma, Paul S; Tkach, Jean A; Fain, Sean B; Woods, Jason C

2017-10-01

To demonstrate that ultrashort echo time (UTE) magnetic resonance imaging (MRI) can achieve computed tomography (CT)-like quantification of lung parenchyma in free-breathing, non-sedated neonates. Because infant CTs are used sparingly, parenchymal disease evaluation via UTE MRI has potential for translational impact. Two neonatal control cohorts without suspected pulmonary morbidities underwent either a research UTE MRI (n = 5; 1.5T) or a clinically-ordered CT (n = 9). Whole-lung means and anterior-posterior gradients of UTE-measured image intensity (arbitrary units, au, normalized to muscle) and CT-measured density (g/cm 3 ) were compared (Mann-Whitney U-test). Separately, a diseased neonatal cohort (n = 5) with various pulmonary morbidities underwent both UTE MRI and CT. UTE intensity and CT density were compared with Spearman correlations within ∼33 anatomically matched regions of interest (ROIs) in each diseased subject, spanning low- to high-density tissues. Radiological classifications were evaluated in all ROIs, with mean UTE intensities and CT densities compared in each classification. In control subjects, whole-lung UTE intensities (0.51 ± 0.04 au) were similar to CT densities (0.44 ± 0.09 g/cm 3 ) (P = 0.062), as were UTE (0.021 ± 0.020 au/cm) and CT (0.034 ± 0.024 [g/cm 3 ]/cm) anterior-posterior gradients (P = 0.351). In diseased subjects' ROIs, significant correlations were observed between UTE and CT (P ≤0.007 in each case). Relative differences between UTE and CT were small in all classifications (4-25%). These results demonstrate a strong association between UTE image intensity and CT density, both between whole-lung tissue in control patients and regional radiological pathologies in diseased patients. This indicates the potential for UTE MRI to longitudinally evaluate neonatal pulmonary disease and to provide visualization of pathologies similar to CT, without sedation/anesthesia or ionizing radiation

Patient satisfaction with coronary CT angiography, myocardial CT perfusion, myocardial perfusion MRI, SPECT myocardial perfusion imaging and conventional coronary angiography

Energy Technology Data Exchange (ETDEWEB)

Feger, S.; Rief, M.; Zimmermann, E.; Richter, F.; Roehle, R. [Freie Universitaet Berlin, Department of Radiology, Charite - Universitaetsmedizin Berlin Campus Mitte, Humboldt-Universitaet zu Berlin, Berlin (Germany); Dewey, M. [Freie Universitaet Berlin, Department of Radiology, Charite - Universitaetsmedizin Berlin Campus Mitte, Humboldt-Universitaet zu Berlin, Berlin (Germany); Institut fuer Radiologie, Berlin (Germany); Schoenenberger, E. [Medizinische Hochschule Hannover, Department of Medicine, Hannover (Germany)

2015-07-15

To evaluate patient acceptance of noninvasive imaging tests for detection of coronary artery disease (CAD), including single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI), stress perfusion magnetic resonance imaging (MRI), coronary CT angiography (CTA) in combination with CT myocardial stress perfusion (CTP), and conventional coronary angiography (CCA). Intraindividual comparison of perception of 48 patients from the CORE320 multicentre multinational study who underwent rest and stress SPECT-MPI with a technetium-based tracer, combined CTA and CTP (both with contrast agent, CTP with adenosine), MRI, and CCA. The analysis was performed by using a validated questionnaire. Patients had significantly more concern prior to CCA than before CTA/CTP (p < 0.001). CTA/CTP was also rated as more comfortable than SPECT-MPI (p = 0.001). Overall satisfaction with CT was superior to that of MRI (p = 0.007). More patients preferred CT (46 %; p < 0.001) as a future diagnostic test. Regarding combined CTA/CTP, CTP was characterised by higher pain levels and an increased frequency of angina pectoris during the examination (p < 0.001). Subgroup analysis showed a higher degree of pain during SPECT-MPI with adenosine stress compared to physical exercise (p = 0.016). All noninvasive cardiac imaging tests are well accepted by patients, with CT being the preferred examination. (orig.)

CT AND MRI FEATURES OF CAROTID BODY PARAGANGLIOMAS IN 16 DOGS.

Science.gov (United States)

Mai, Wilfried; Seiler, Gabriela S; Lindl-Bylicki, Britany J; Zwingenberger, Allison L

2015-01-01

Carotid body tumors (paragangliomas) arise from chemoreceptors located at the carotid bifurcation. In imaging studies, this neoplasm may be confused with other neck neoplasms such as thyroid carcinoma. The purpose of this retrospective, cross-sectional study was to describe computed tomographic (CT) and magnetic resonance imaging (MRI) characteristics of confirmed carotid body tumors in a multi-institutional sample of dogs. A total of 16 dogs met inclusion criteria (14 examined using CT and two with MRI). The most common reason for imaging was a palpable cervical mass or respiratory signs (i.e., dyspnea or increased respiratory noises). The most commonly affected breed was Boston terrier (n = 5). Dogs were predominantly male castrated (n = 10) and the median age was 9 years [range 3-14.5]. Most tumors appeared as a large mass centered at the carotid bifurcation, with poor margination in six dogs and discrete margins in ten dogs. Masses were iso- to hypoattenuating to adjacent muscles in CT images and hyperintense to muscles in T1- and T2-weighted MRI. For both CT and MRI, masses typically showed strong and heterogeneous contrast enhancement. There was invasion into the adjacent structures in 9/16 dogs. In six of these nine dogs, the basilar portion of the skull was affected. The external carotid artery was entrapped in seven dogs. There was invasion into the internal jugular vein in three dogs, and into the external jugular, maxillary, and linguo-facial veins in one dog. Imaging characteristics helped explain some clinical presentations such as breathing difficulties, Horner's syndrome, head tilt, or facial nerve paralysis. © 2015 American College of Veterinary Radiology.

Medulloblastoma in children: CT and MRI findings

International Nuclear Information System (INIS)

Tortori-Donati, P.; Fondelli, M.P.; Rossi, A.; Cama, A.; Caputo, L.; Andreussi, L.; Garre, M.L.

1996-01-01

Our purpose was to determine whether medulloblastoma (MB) shows specific neuroradiological features which may be employed in differential diagnosis from other common posterior cranial fossa tumours in childhood. Preoperative MRI was performed on 20 children with MB, and preoperative CT in 17 of them. All underwent surgery and histopathological diagnosis. There was a constant relationship between high density on CT and low signal on T1-weighted images. Signal behaviour on T2-weighted images and the degree of contrast enhancement were more variable. Most tumours arose in the midline, from the cerebellar vermis, involving the fourth ventricle, but hemisphere and extra-axial neoplasms were also seen. The combination of high density on CT and low signal on T1-weighted images is highly suggestive of MB and may assist preoperative differential diagnosis from other posterior cranial fossa tumours. (orig.). With 9 figs., 2 tabs

A proposal for combined MRI and PET/CT interpretation criteria for preoperative nodal staging in non-small-cell lung cancer

International Nuclear Information System (INIS)

Kim, Yoo Na; Yi, Chin A.; Lee, Kyung Soo; Lee, Ho Yun; Kim, Tae Sung; Chung, Myung Jin; Kwon, O.Jung; Chung, Man Pyo; Kim, Byung-Tae; Choi, Joon Young; Kim, Seon Woo; Han, Joungho; Shim, Young Mog

2012-01-01

To determine the positive reading criteria for malignant nodes when interpreting combined MRI and PET/CT images for preoperative nodal staging in non-small-cell lung cancer (NSCLC). Forty-nine patients with biopsy-proven NSCLC underwent both PET/CT and thoracic MRI [diffusion weighted imaging (DWI)]. Each nodal station was evaluated for the presence of metastasis by applying either inclusive (positive if either one read positive) or exclusive (positive if both read positive) criteria in the combined interpretation of PET/CT and MRI. Nodal stage was confirmed pathologically. The combined diagnostic accuracy of PET/CT and MRI was determined on per-nodal station and per-patient bases and compared with that of PET/CT alone. In 49 patients, 39 (19%) of 206 nodal stations harboured malignant cells. Out of 206 nodal stations, 186 (90%) had concordant readings, while the rest (10%) had discordant readings. Inclusive criteria of combined PET/CT and MRI helped increase sensitivity for detecting nodal metastasis (69%) compared with PET/CT alone (46%; P = 0.003), while specificity was not significantly decreased. Inclusive criteria in combined MRI and PET/CT readings help improve significantly the sensitivity for detecting nodal metastasis compared with PET/CT alone and may decrease unnecessary open thoracotomy. (orig.)

Preliminary results of a new workflow for MRI/CT-based image-guided brachytherapy in cervical carcinoma.

Science.gov (United States)

Nemoto, Miho Watanabe; Iwai, Yuma; Togasaki, Gentaro; Kurokawa, Marie; Harada, Rintarou; Kobayashi, Hiroki; Uno, Takashi

2017-12-01

We propose a method of image-guided brachytherapy (IGBT) that combines MRI-based target volume delineation for the first fraction with CT datasets of subsequent fractions, using an automatic, applicator-based co-registration, and report our preliminary experience. The MRI of the first fraction was used for the first brachytherapy planning. For each subsequent brachytherapy fraction, after the same applicator insertion, a new CT scan with the applicator in place was obtained. The MR image set was registered to the subsequent brachytherapy treatment planning CT using the applicator for rigid body registration. To demonstrate the registration quality, we used here the Dice index as a measurement of tandem delineation overlap between CT and MRI. The median Dice index was 0.879 (range 0.610-0.932), which indicated that the contours on CT and MRI fitted well. With this combination method, the median D90 of HR CTV and the calculated D2 cm 3 of the bladder, rectum, and sigmoid in each fraction were 7.2 (4.0-10.4), 5.9 (2.3-7.7), 4.0 (1.9-6.7), and 3.8 (0.6-7.2) Gy, respectively. Our described method of MRI-guided IGBT offers a practical option for the benefits of target delineation.

Automated pulmonary lobar ventilation measurements using volume-matched thoracic CT and MRI

Science.gov (United States)

Guo, F.; Svenningsen, S.; Bluemke, E.; Rajchl, M.; Yuan, J.; Fenster, A.; Parraga, G.

2015-03-01

Objectives: To develop and evaluate an automated registration and segmentation pipeline for regional lobar pulmonary structure-function measurements, using volume-matched thoracic CT and MRI in order to guide therapy. Methods: Ten subjects underwent pulmonary function tests and volume-matched 1H and 3He MRI and thoracic CT during a single 2-hr visit. CT was registered to 1H MRI using an affine method that incorporated block-matching and this was followed by a deformable step using free-form deformation. The resultant deformation field was used to deform the associated CT lobe mask that was generated using commercial software. 3He-1H image registration used the same two-step registration method and 3He ventilation was segmented using hierarchical k-means clustering. Whole lung and lobar 3He ventilation and ventilation defect percent (VDP) were generated by mapping ventilation defects to CT-defined whole lung and lobe volumes. Target CT-3He registration accuracy was evaluated using region- , surface distance- and volume-based metrics. Automated whole lung and lobar VDP was compared with semi-automated and manual results using paired t-tests. Results: The proposed pipeline yielded regional spatial agreement of 88.0+/-0.9% and surface distance error of 3.9+/-0.5 mm. Automated and manual whole lung and lobar ventilation and VDP were not significantly different and they were significantly correlated (r = 0.77, p pulmonary structural-functional maps with high accuracy and robustness, providing an important tool for image-guided pulmonary interventions.

Value of retrospective image fusion of {sup 18}F-FDG PET and MRI for preoperative staging of head and neck cancer: Comparison with PET/CT and contrast-enhanced neck MRI

Energy Technology Data Exchange (ETDEWEB)

Kanda, Tomonori [Department of Radiology, Kobe University Graduate School of Medicine, Kobe (Japan); Department of Radiology, Hyogo Cancer Center, Hyogo (Japan); Kitajima, Kazuhiro, E-mail: kitajima@med.kobe-u.ac.jp [Department of Radiology, Kobe University Graduate School of Medicine, Kobe (Japan); Suenaga, Yuko; Konishi, Jyunya [Department of Radiology, Kobe University Graduate School of Medicine, Kobe (Japan); Sasaki, Ryohei [Division of Radiation Oncology, Department of Radiology, Kobe University Graduate School of Medicine, Kobe (Japan); Morimoto, Koichi; Saito, Miki; Otsuki, Naoki; Nibu, Ken-ichi [Department of Otolaryngology-Head and Neck Surgery, Kobe University Graduate School of Medicine, Kobe (Japan); Sugimura, Kazuro [Department of Radiology, Kobe University Graduate School of Medicine, Kobe (Japan)

2013-11-01

Purpose: To assess the clinical value of retrospective image fusion of neck MRI and {sup 18}F-fluorodeoxyglucose ({sup 18}F-FDG) PET for locoregional extension and nodal staging of neck cancer. Materials and methods: Thirty patients with carcinoma of the oral cavity or hypopharynx underwent PET/CT and contrast-enhanced neck MRI for initial staging before surgery including primary tumor resection and neck dissection. Diagnostic performance of PET/CT, MRI, and retrospective image fusion of PET and MRI (fused PET/MRI) for assessment of the extent of the primary tumor (T stage) and metastasis to regional lymph nodes (N stage) was evaluated. Results: Accuracy for T status was 87% for fused PET/MRI and 90% for MRI, thus proving significantly superior to PET/CT, which had an accuracy of 67% (p = 0.041 and p = 0.023, respectively). Accuracy for N status was 77% for both fused PET/MRI and PET/CT, being superior to MRI, which had an accuracy of 63%, although the difference was not significant (p = 0.13). On a per-level basis, the sensitivity, specificity and accuracy for detection of nodal metastasis were 77%, 96% and 93% for both fused PET/MRI and PET/CT, compared with 49%, 99% and 91% for MRI, respectively. The differences for sensitivity (p = 0.0026) and accuracy (p = 0.041) were significant. Conclusion: Fused PET/MRI combining the individual advantages of MRI and PET is a valuable technique for assessment of staging neck cancer.

Cerebral lymphoma - CT and MRI diagnostic

International Nuclear Information System (INIS)

Popovska, T.; Yanakiev, A.; Zashev, I.

2012-01-01

Lymphoma (Hodgkin's and non-Hodgkin's) is a disease of the lymphatic system where the central neural system is affected in very rare cases. According to different authors the frequency of cases with lymphoma where the neural system is affected varies between 0, 2 % and 0, 5 %, and the primary cerebral lymphoma accounts for about 1-2% of ail brain neoplasms. The intracranial form of iymphoma is usually a late onset of the disease with serious and potentially fatal complications for the patient. These complications usually appear several years after diagnosing the disease, but the cerebral lymphoma may occur even in patients who are in remission which is the case with our patient. We present you a case with a 38 -year-old female, who was hospitalized in the Neuro ward with the following complaints -loss of speech for a few minutes, dizziness, weakness, tingling in her right leg as well as shuffling. This patient was diagnosed with histological B-cell non-Hodgkin's lymphoma 8 years ago. CT and MRI were carried out on that patient. Despite both clinical and radiographic suspicions for intracranial forms of lymphoma, the patient was still difficult to diagnose. A definitive diagnosis was given after a surgery and histological examination, i.e. non-Hodgkin's lymphoma - large B-cell lymphoma. This case is of interest because of its rare intracranial localization of the lymphoma. The knowledge of CT and MRI images of the intracranial form of lymphoma may help diagnosing, but images should be interpreted together with the clinical and paraclinical results Hodgkin's and non-Hodgkin's) is a disease of the lymphatic system where the central neural system is affected in very rare cases. According to different authors the frequency of cases with lymphoma where the neural system is affected varies between 0, 2 % and 0, 5 %, and the primary cerebral lymphoma accounts for about 1-2% of ail brain neoplasms. The intracranial form of iymphoma is usually a late onset of the disease

Contribution of brain imaging techniques: CT-scan and magnetic resonance imaging (MRI)

International Nuclear Information System (INIS)

Pasco-Papon, A.; Gourdier, A.L.; Papon, X.; Caron-Poitreau, C.

1996-01-01

In light of the current lack of consensus on the benefit of carotid artery surgery to treat asymptomatic carotid artery stenosis, the decision to operate on a patient depends on individual evaluation and characterization of risk factors on carotid artery stenosis greater than 70 %. The assessment of such risk factors is based especially on non-invasive brain imaging techniques.Computed tomography scanning (CT-scan) and magnetic resonance imaging (MRI) enable two types of stenosis to be differentiated, i.e. stenoses which are symptomatic and those that are radiologically proven versus those which are clinically and radiologically silent. CT-scan investigation (with and without injection of iodinated contrast media) still continues to be a common routine test in 1996 whenever a surgical revascularization procedure is planned. The presence of deep lacunar infarcts ipsilateral to the carotid artery stenosis generally evidence the reality of stenosis and thus are useful to the surgeon in establishing whether surgery is indicated. In the absence a consensus on indications for surgical management, the surgeon could use the CT-scan and MRI as medicolegal records which could be compared to a subsequent postoperative CT-scan in case of ischemic complications associated with the surgical procedure. Furthermore, recent cerebral ischemia as evidenced by filling with contrast material, will call for postponing treatment by a few weeks. Although conventional MRI is more contributive than brain CT-scan in terms of sensibility and specificity, its indications are narrower because of its limited availability and cost constraints. But, development of angio-MRI and functional imaging promise that its future is assured and even perhaps as the sole diagnostic method if its indications are expanded to include preoperative angiographic evaluation of atheromatous lesions of supra-aortic trunks. (authors). 37 refs

An image acquisition and registration strategy for the fusion of hyperpolarized helium-3 MRI and x-ray CT images of the lung

International Nuclear Information System (INIS)

Ireland, Rob H; Woodhouse, Neil; Hoggard, Nigel; Swinscoe, James A; Foran, Bernadette H; Hatton, Matthew Q; Wild, Jim M

2008-01-01

The purpose of this ethics committee approved prospective study was to evaluate an image acquisition and registration protocol for hyperpolarized helium-3 magnetic resonance imaging ( 3 He-MRI) and x-ray computed tomography. Nine patients with non-small cell lung cancer (NSCLC) gave written informed consent to undergo a free-breathing CT, an inspiration breath-hold CT and a 3D ventilation 3 He-MRI in CT position using an elliptical birdcage radiofrequency (RF) body coil. 3 He-MRI to CT image fusion was performed using a rigid registration algorithm which was assessed by two observers using anatomical landmarks and a percentage volume overlap coefficient. Registration of 3 He-MRI to breath-hold CT was more accurate than to free-breathing CT; overlap 82.9 ± 4.2% versus 59.8 ± 9.0% (p 3 He-MRI and CT to be acquired with similar breath holds and body position through the use of a birdcage 3 He-MRI body RF coil and an inspiration breath-hold CT. Fusion of 3 He-MRI to CT may be useful for the assessment of patients with lung diseases.

An update on the role of PET/CT and PET/MRI in ovarian cancer

International Nuclear Information System (INIS)

Khiewvan, Benjapa; Torigian, Drew A.; Emamzadehfard, Sahra; Paydary, Koosha; Salavati, Ali; Houshmand, Sina; Werner, Thomas J.; Alavi, Abass

2017-01-01

This review article summarizes the role of PET/CT and PET/MRI in ovarian cancer. With regard to the diagnosis of ovarian cancer, the presence of FDG uptake within the ovary of a postmenopausal woman raises the concern for ovarian cancer. Multiple studies show that FDG PET/CT can detect lymph node and distant metastasis in ovarian cancer with high accuracy and may, therefore, alter the management to obtain better clinical outcomes. Although PET/CT staging is superior for N and M staging of ovarian cancer, its role is limited for T staging. Additionally, FDG PET/CT is of great benefit in evaluating treatment response and has prognostic value in patients with ovarian cancer. FDG PET/CT also has value to detect recurrent disease, particularly in patients with elevated serum CA-125 levels and negative or inconclusive conventional imaging test results. PET/MRI may beneficial for tumor staging because MRI has higher soft tissue contrast and no ionizing radiation exposure compared to CT. Some non-FDG PET radiotracers such as 18 F-fluorothymidine (FLT) or 11 C-methionine (MET) have been studied in preclinical and clinical studies as well and may play a role in the evaluation of patients with ovarian cancer. (orig.)

An update on the role of PET/CT and PET/MRI in ovarian cancer

Energy Technology Data Exchange (ETDEWEB)

Khiewvan, Benjapa [Hospital of the University of Pennsylvania, Department of Radiology, Philadelphia, PA (United States); Mahidol University, Division of Nuclear Medicine, Department of Radiology, Faculty of Medicine Siriraj Hospital, Bangkok (Thailand); Torigian, Drew A.; Emamzadehfard, Sahra; Paydary, Koosha; Salavati, Ali; Houshmand, Sina; Werner, Thomas J.; Alavi, Abass [Hospital of the University of Pennsylvania, Department of Radiology, Philadelphia, PA (United States)

2017-06-15

This review article summarizes the role of PET/CT and PET/MRI in ovarian cancer. With regard to the diagnosis of ovarian cancer, the presence of FDG uptake within the ovary of a postmenopausal woman raises the concern for ovarian cancer. Multiple studies show that FDG PET/CT can detect lymph node and distant metastasis in ovarian cancer with high accuracy and may, therefore, alter the management to obtain better clinical outcomes. Although PET/CT staging is superior for N and M staging of ovarian cancer, its role is limited for T staging. Additionally, FDG PET/CT is of great benefit in evaluating treatment response and has prognostic value in patients with ovarian cancer. FDG PET/CT also has value to detect recurrent disease, particularly in patients with elevated serum CA-125 levels and negative or inconclusive conventional imaging test results. PET/MRI may beneficial for tumor staging because MRI has higher soft tissue contrast and no ionizing radiation exposure compared to CT. Some non-FDG PET radiotracers such as {sup 18}F-fluorothymidine (FLT) or {sup 11}C-methionine (MET) have been studied in preclinical and clinical studies as well and may play a role in the evaluation of patients with ovarian cancer. (orig.)

T1-weighted MRI as a substitute to CT for refocusing planning in MR-guided focused ultrasound

International Nuclear Information System (INIS)

Wintermark, Max; Sumer, Suna; Lau, Benison; Cupino, Alan; Tustison, Nicholas J; Demartini, Nicholas; Elias, William J; Kassell, Neal; Patrie, James T; Xin, Wenjun; Eames, Matt; Snell, John; Hananel, Arik; Aubry, Jean-Francois

2014-01-01

Precise focusing is essential for transcranial MRI-guided focused ultrasound (TcMRgFUS) to minimize collateral damage to non-diseased tissues and to achieve temperatures capable of inducing coagulative necrosis at acceptable power deposition levels. CT is usually used for this refocusing but requires a separate study (CT) ahead of the TcMRgFUS procedure. The goal of this study was to determine whether MRI using an appropriate sequence would be a viable alternative to CT for planning ultrasound refocusing in TcMRgFUS. We tested three MRI pulse sequences (3D T1 weighted 3D volume interpolated breath hold examination (VIBE), proton density weighted 3D sampling perfection with applications optimized contrasts using different flip angle evolution and 3D true fast imaging with steady state precision T2-weighted imaging) on patients who have already had a CT scan performed. We made detailed measurements of the calvarial structure based on the MRI data and compared those so-called ‘virtual CT’ to detailed measurements of the calvarial structure based on the CT data, used as a reference standard. We then loaded both standard and virtual CT in a TcMRgFUS device and compared the calculated phase correction values, as well as the temperature elevation in a phantom. A series of Bland–Altman measurement agreement analyses showed T1 3D VIBE as the optimal MRI sequence, with respect to minimizing the measurement discrepancy between the MRI derived total skull thickness measurement and the CT derived total skull thickness measurement (mean measurement discrepancy: 0.025; 95% CL (−0.22–0.27); p = 0.825). The T1-weighted sequence was also optimal in estimating skull CT density and skull layer thickness. The mean difference between the phase shifts calculated with the standard CT and the virtual CT reconstructed from the T1 dataset was 0.08 ± 1.2 rad on patients and 0.1 ± 0.9 rad on phantom. Compared to the real CT, the MR-based correction showed a 1 °C drop on the

18F-Fluorodeoxyglucose PET/CT and dynamic contrast-enhanced MRI as imaging biomarkers in malignant pleural mesothelioma

OpenAIRE

Hall, D. O.; Hooper, C. E.; Searle, J.; Darby, M.; White, P.; Harvey, J. E.; Braybrooke, J. P.; Maskell, N. A.; Masani, V.; Lyburn, I. D.

2018-01-01

Purpose\\ud \\ud The purpose of this study was to compare the use of fluorine-18-fluorodeoxyglucose (18F-FDG) PET with computed tomography (CT) and dynamic contrast-enhanced (DCE) MRI to predict prognosis and monitor treatment in malignant pleural mesothelioma.\\ud \\ud Patients and methods\\ud \\ud 18F-FDG PET/CT and DCE-MRI studies carried out as part of the South West Area Mesothelioma Pemetrexed trial were used. 18F-FDG PET/CT and DCE-MRI studies were carried out before treatment, and after two...

MRI features of myositis ossificans with X-ray and CT findings

International Nuclear Information System (INIS)

Gu Xiang; Bai Rongjie; Qu Hui; Cheng Xiaoguang; Li Yuang

2009-01-01

Objective: To investigate the MRI features of myositis ossificans, and to address the correlation with X-ray radiography and CT findings. Methods: X-ray films, CT and MRI of 36 documented cases of myositis ossificans were retrospectively analyzed, and the literatures were reviewed. Results: Of the 36 cases, 4 cases occurred in the elbow joint, 4 in the shoulder joint, 15 in the hip joint, 6 in the tibiofibula, 5 in the femur, 1 in the metatarsal bones, and 1 in the ilium, respectively. Irregular patchy or lamellar high density calcification or ossification could be seen in the soft tissue parenchym on X-ray films and CT scan. Cortical bone integrity was preserved in diaphysis. CT enhanced scan showed that the swollen parenchyma was not enhanced and there was no parenchyma mass. On the early and middle stages, MR T 1 WI and T 2 WI showed slice-shaped low signal in the peripheral parenchyma, but patchy high signal was found around the low signal on T 2 WI. STIR showed mixed high and low signals in the swollen parenchyma with unclear demarcation. The lesions showed low signal on MR T 1 WI and T 2 WI in the late stage, and there was no edema in peripheral parenehyma. MRI enhanced scan found that the swollen parenchyma showed no enhancement in all stages. Conclusions: The imaging features of myositis ossificans have some characteristics. Misdiagnosis could be avoided when the disease was evaluated with the course. (authors)

Investigation of CT and MRI findings of cranio-orbital communicating lesions

International Nuclear Information System (INIS)

Wang Zhenchang; Jiang Dingyao; Xian Junfang; An Yuzhi; Zhang Tianming; Li Bin; Liang Xihong; Yang Bentao

2001-01-01

Objective: To investigate CT and MRI findings of cranio-orbital communicating lesions so as to find out communicating passages and their imaging features. Methods: Fifty-one cases of cranio-orbital communicating lesions confirmed by pathology and follow-up results were studied. CT was performed in all cases and MRI in 45 cases. Post-contrast CT and MRI was completed in 44 cases. Results: There were 31 cases (60.8%) with lesions communicating between the orbital cavity and the cranial cavity through optic canal or superior orbital fissure showing communicating soft tissue mass and enlargement of optic canal or superior orbital fissure. Four cases of optic gliomas involving optic nerve and optic chiasm, three cases with meningiomas of optic nerve sheath, and 2 cases with retinoblastoma involving optic nerve and optic chiasm showed cranio-orbital communicating masses through the optic canal. Cranio-orbital communicating mass with enlargement of superior orbital fissure was found in 22 patients including 5 meningiomas, 4 neurogenic tumors, 1 dermoid cyst, 3 inflammatory pseudotumors, 2 Tolosa-Hunt syndromes and 7 metastases from nasopharyngeal carcinoma. In addition, 20 of 51 cases (39.2%) communicated through perforating blood vessels or bony defect resulted from tumor destruction. Of these lesions, there were 10 metastases showing bone destruction in orbital walls, 5 cases with en plaque meningiomas of sphenoid bone with marked hyperostosis and widespread dural involvement, 1 chondrosarcoma involving frontal lobe and orbit, 3 adenoid cystic carcinomas involving frontal lobe, and 1 malignant meningioma with bone destruction of the superior orbital wall. Conclusion: CT and MRI could definitely demonstrate communicating passages of cranio-orbital communicating lesions and their imaging changes, which could contribute to diagnosis and differential diagnosis and provide valuable information for determining treatment measures and surgical approach

Serial MRI findings of osteoporotic vertebral fractures in the thoracic and lumbar spine

International Nuclear Information System (INIS)

Hamada, Yoshitaka; Henmi, Tatsuhiko; Sakamoto, Rintaro; Hiasa, Masahiko

1998-01-01

The prognosis of osteoporotic vertebral fractures in the thoracic and lumbar spine was studied by serial MRI findings. This study covered 80 vertebrae in 69 patients treated conservatively and followed-up for more than six months (23 males and 46 females, average age 70 yrs). Group A, characterized by poor diagnostic imaging, consisted of patients who had both severely collapsed vertebra which was progressive in the lateral roentgenogram and delayed improvement in MRI signal intensities. Group B, consisting of poor clinical prognosis, comprised patients with persistent back pain. The predictive factors for Group A were found to be T 1 -low finding over the entire vertebra within one month after injury and fractures of Th 12 or L 1 vertebra. Areas of T 1 -low and T 2 -low intensity adjacent to the vertebral disc presented no improvement in signal intensity and often caused persistent back pain. (author)

CT- and MRI-based volumetry of resected liver specimen: Comparison to intraoperative volume and weight measurements and calculation of conversion factors

International Nuclear Information System (INIS)

Karlo, C.; Reiner, C.S.; Stolzmann, P.; Breitenstein, S.; Marincek, B.; Weishaupt, D.; Frauenfelder, T.

2010-01-01

Objective: To compare virtual volume to intraoperative volume and weight measurements of resected liver specimen and calculate appropriate conversion factors to reach better correlation. Methods: Preoperative (CT-group, n = 30; MRI-group, n = 30) and postoperative MRI (n = 60) imaging was performed in 60 patients undergoing partial liver resection. Intraoperative volume and weight of the resected liver specimen was measured. Virtual volume measurements were performed by two readers (R1,R2) using dedicated software. Conversion factors were calculated. Results: Mean intraoperative resection weight/volume: CT: 855 g/852 mL; MRI: 872 g/860 mL. Virtual resection volume: CT: 960 mL(R1), 982 mL(R2); MRI: 1112 mL(R1), 1115 mL(R2). Strong positive correlation for both readers between intraoperative and virtual measurements, mean of both readers: CT: R = 0.88(volume), R = 0.89(weight); MRI: R = 0.95(volume), R = 0.92(weight). Conversion factors: 0.85(CT), 0.78(MRI). Conclusion: CT- or MRI-based volumetry of resected liver specimen is accurate and recommended for preoperative planning. A conversion of the result is necessary to improve intraoperative and virtual measurement correlation. We found 0.85 for CT- and 0.78 for MRI-based volumetry the most appropriate conversion factors.

The value of CT and MRI in the classification and surgical decision-making among spine surgeons in thoracolumbar spinal injuries.

Science.gov (United States)

Rajasekaran, Shanmuganathan; Vaccaro, Alexander R; Kanna, Rishi Mugesh; Schroeder, Gregory D; Oner, Frank Cumhur; Vialle, Luiz; Chapman, Jens; Dvorak, Marcel; Fehlings, Michael; Shetty, Ajoy Prasad; Schnake, Klaus; Maheshwaran, Anupama; Kandziora, Frank

2017-05-01

Although imaging has a major role in evaluation and management of thoracolumbar spinal trauma by spine surgeons, the exact role of computed tomography (CT) and magnetic resonance imaging (MRI) in addition to radiographs for fracture classification and surgical decision-making is unclear. Spine surgeons (n = 41) from around the world classified 30 thoracolumbar fractures. The cases were presented in a three-step approach: first plain radiographs, followed by CT and MRI images. Surgeons were asked to classify according to the AOSpine classification system and choose management in each of the three steps. Surgeons correctly classified 43.4 % of fractures with plain radiographs alone; after, additionally, evaluating CT and MRI images, this percentage increased by further 18.2 and 2.2 %, respectively. AO type A fractures were identified in 51.7 % of fractures with radiographs, while the number of type B fractures increased after CT and MRI. The number of type C fractures diagnosed was constant across the three steps. Agreement between radiographs and CT was fair for A-type (k = 0.31), poor for B-type (k = 0.19), but it was excellent between CT and MRI (k > 0.87). CT and MRI had similar sensitivity in identifying fracture subtypes except that MRI had a higher sensitivity (56.5 %) for B2 fractures (p change after an MRI (p = 0.77). For accurate classification, radiographs alone were insufficient except for C-type injuries. CT is mandatory for accurately classifying thoracolumbar fractures. Though MRI did confer a modest gain in sensitivity in B2 injuries, the study does not support the need for routine MRI in patients for classification, assessing instability or need for surgery.

MRI, CT, and sonography in the preoperative evaluation of primary tumor extension in malignant pleural mesothelioma

International Nuclear Information System (INIS)

Layer, G.; Steudel, A.; Schild, H.H.; Schmitteckert, H.; Tuengerthal, S.; Schirren, J.; Kaick, G. van

1999-01-01

Purpose: Evaluation of the diagnostic value of the imaging modalities computed tomography (CT), magnetic resonance imaging (MRI), and thoracic sonography in the preoperative staging of malignant pleural mesothelioma. Results: The accuracy rates for CT were 85%, 98%, 83%, 73%, 71%, and 83%. MRI had an accuracy of 71%, 92%, 71%, 83%, 71%, and 96%, the thoracic ultrasound examinations of 76%, 63%, 51%, 60%, 71% and 89%. Conclusions: According to these results CT remains the method of choice in the preoperative assessment of T-stage of malignant pleural mesothelioma. MRI is of nearly the same value, but is not a must. Sonography may be supplementary method for operation planning. (orig./AJ) [de

Converting from CT- to MRI-only-based target definition in radiotherapy of localized prostate cancer: A comparison between two modalities.

Science.gov (United States)

Seppälä, Tiina; Visapää, Harri; Collan, Juhani; Kapanen, Mika; Beule, Annette; Kouri, Mauri; Tenhunen, Mikko; Saarilahti, Kauko

2015-11-01

To investigate the conversion of prostate cancer radiotherapy (RT) target definition from CT-based planning into an MRI-only-based planning procedure. Using the CT- and MRI-only-based RT planning protocols, 30 prostate cancer patients were imaged in the RT fixation position. Two physicians delineated the prostate in both CT and T2-weighted MRI images. The CT and MRI images were coregistered based on gold seeds and anatomic borders of the prostate. The uncertainty of the coregistration, as well as differences in target volumes and uncertainty of contour delineation were investigated. Conversion of margins and dose constraints from CT- to MRI-only-based treatment planning was assessed. On average, the uncertainty of image coregistration was 0.4 ± 0.5 mm (one standard deviation, SD), 0.9 ± 0.8 mm and 0.9 ± 0.9 mm in the lateral, anterior-posterior and base-apex direction, respectively. The average ratio of the prostate volume between CT and MRI was 1.20 ± 0.15 (one SD). Compared to the CT-based contours, the MRI-based contours were on average 2-7 mm smaller in the apex, 0-1 mm smaller in the rectal direction and 1-4 mm smaller elsewhere. When converting from a CT-based planning procedure to an MRI-based one, the overall planning target volumes (PTV) are prominently reduced only in the apex. The prostate margins and dose constraints can be retained by this conversion.

Are the osseous and tendinous-cartilaginous tibial tuberosity-trochlear groove distances the same on CT and MRI?

International Nuclear Information System (INIS)

Bremer Hinckel, Betina; Gomes Gobbi, Riccardo; Pecora, Jose Ricardo; Camanho, Gilberto Luis; Demange, Marco Kawamura; Noda Kihara Filho, Eduardo; Bordalo Rodrigues, Marcelo

2015-01-01

To verify whether the tibial tuberosity-trochlear groove distance (TT-TG) and the tendinous-cartilaginous TT-TG (the distance between the patellar tendon and trochlear groove: PT-TG) are identical using computed tomography (CT) and magnetic resonance imaging (MRI) techniques. The TT-TG and PT-TG distances were measured on the same knee samples by three observers (two measurements per observer) using CT and MRI scans collected retrospectively. The reproducibility of the measurements was assessed using the interclass correlation coefficient (ICC). The means and standard deviations of four measurements were calculated for each patient. A paired t-test was used to assess differences between measurements. Fifty knee samples (32 with patellar instability and 18 with other conditions) were evaluated. The inter- and intraobserver reliability was excellent for all four measurements (>0.8). On average, the TT-TG distance on MRI was 3.1-3.6 mm smaller than that on CT, and the PT-TG distance on MRI was 1.0-3.4 mm larger than the TT-TG distance on MRI. The osseous TT-TG and tendinous-cartilaginous PT-TG distances determined by CT and MRI were not identical. (orig.)

Are the osseous and tendinous-cartilaginous tibial tuberosity-trochlear groove distances the same on CT and MRI?

Energy Technology Data Exchange (ETDEWEB)

Bremer Hinckel, Betina; Gomes Gobbi, Riccardo; Pecora, Jose Ricardo; Camanho, Gilberto Luis; Demange, Marco Kawamura [Institute of Orthopaedics and Traumatology of the Clinical Hospital of the Medical School of the University of Sao Paulo, Department of Orthopaedics, Sao Paulo (Brazil); Noda Kihara Filho, Eduardo; Bordalo Rodrigues, Marcelo [Institute of Orthopaedics and Traumatology of the Clinical Hospital of the Medical School of the University of Sao Paulo, Department of Musculoskeletal Radiology, Sao Paulo (Brazil)

2015-08-15

To verify whether the tibial tuberosity-trochlear groove distance (TT-TG) and the tendinous-cartilaginous TT-TG (the distance between the patellar tendon and trochlear groove: PT-TG) are identical using computed tomography (CT) and magnetic resonance imaging (MRI) techniques. The TT-TG and PT-TG distances were measured on the same knee samples by three observers (two measurements per observer) using CT and MRI scans collected retrospectively. The reproducibility of the measurements was assessed using the interclass correlation coefficient (ICC). The means and standard deviations of four measurements were calculated for each patient. A paired t-test was used to assess differences between measurements. Fifty knee samples (32 with patellar instability and 18 with other conditions) were evaluated. The inter- and intraobserver reliability was excellent for all four measurements (>0.8). On average, the TT-TG distance on MRI was 3.1-3.6 mm smaller than that on CT, and the PT-TG distance on MRI was 1.0-3.4 mm larger than the TT-TG distance on MRI. The osseous TT-TG and tendinous-cartilaginous PT-TG distances determined by CT and MRI were not identical. (orig.)

Multiphasic contrast-enhanced CT and MRI findings of adult mesoblastic nephroma: A report of two cases

Directory of Open Access Journals (Sweden)

Yuqin Ding

2013-01-01

Full Text Available Mesoblastic nephroma (MN presenting in an adult is extremely rare. The computed tomography (CT and magnetic resonance imaging (MRI features of this tumor in adulthood have not been widely reported. We present two additional cases of adult MN and describe the multiphasic contrast-enhanced CT and MRI findings.

Image registration/fusion software for PET and CT/MRI by using simultaneous emission and transmission scans

International Nuclear Information System (INIS)

Kitamura, Keishi; Amano, Masaharu; Sato, Tomohiko; Okumura, Takeshi; Konishi, Norihiro; Komatsu, Masahiko

2003-01-01

When PET (positron emission tomography) is used for oncology studies, it is important to register and over-lay PET images with the images of other anatomical modalities, such as those obtained by CT (computed tomography) or MRI (magnetic resonance imaging), in order for the lesions to be anatomically located with high accuracy. The Shimadzu SET-2000W Series PET scanners provide simultaneous acquisition of emission and transmission data, which is capable of complete spatial alignment of both functional and attenuation images. This report describes our newly developed image registration/fusion software, which reformats PET emission images to the CT/MRI grid by using the transform matrix obtained by matching PET transmission images with CT/MRI images. Transmission images are registered and fused either automatically or manually, through 3-dimensional rotation and translation, with the transaxial, sagittal, and coronal fused images being monitored on the screen. This new method permits sufficiently accurate registration and efficient data processing with promoting effective use of CT/MRI images of the DICOM format, without using markers in data acquisition or any special equipment, such as a combined PET/CT scanner. (author)

The evaluation of CT and MRI in the diagnosis of pancreatic tuberculosis and peripancreatic tuberculous lymphadenopathy

International Nuclear Information System (INIS)

Yang Zenian; Wang Xiaoyan; Peng Zhenpeng; Lin Jianqin; Zhang Ting

2008-01-01

Objective: To study the manifestations and its pathologic basis of pancreatic tubeiculosis and peripancreatic tuberculous lymphadenopathy. And evaluate the diagnostic values of CT and MRI. Methods: Two cases of pancreatic tuberculosis and eleven cases of peripancreatic tuberculous lymphadenopathy were collected. All cases were conformed by pathology or clinic. Plain scan and enhanced scan with spiral CT were performed in all cases. Plain scan and enhanced scan with MRI were performed in two cases. The CT and MRI features of 13 cases were analyzed retrospectively. Results: Pancreatic tuberculosis showed that the lesion was located mainly at the head of the pancreas and displayed on CT as a low-density mass with marginal or honeycomb enhancement. Peripancreatic tuberculous lymphadenopathy was seen in 11 cases, of which ring-like enhancement was seen in seven cases, calcifications in two cases and mixed in two cases. Splenic involvement was found in five cases. Conclusion: Pancreatic tuberculosis and peripancreatic tuberculous lymphadenopathy have the main features of low-density mass With marginal or honeycomb enhancement and ting-like enhancement in petipancreatic lymphadenopathy. CT and MRI are feasible methods in diagnosis of pancreatic tuberculosis and peripancreatic tuberculous lymphadenopathy. (authors)

Role of FDG-PET/MRI, FDG-PET/CT, and Dynamic Susceptibility Contrast Perfusion MRI in Differentiating Radiation Necrosis from Tumor Recurrence in Glioblastomas.

Science.gov (United States)

Hojjati, Mojgan; Badve, Chaitra; Garg, Vasant; Tatsuoka, Curtis; Rogers, Lisa; Sloan, Andrew; Faulhaber, Peter; Ros, Pablo R; Wolansky, Leo J

2018-01-01

To compare the utility of quantitative PET/MRI, dynamic susceptibility contrast (DSC) perfusion MRI (pMRI), and PET/CT in differentiating radiation necrosis (RN) from tumor recurrence (TR) in patients with treated glioblastoma multiforme (GBM). The study included 24 patients with GBM treated with surgery, radiotherapy, and temozolomide who presented with progression on imaging follow-up. All patients underwent PET/MRI and pMRI during a single examination. Additionally, 19 of 24 patients underwent PET/CT on the same day. Diagnosis was established by pathology in 17 of 24 and by clinical/radiologic consensus in 7 of 24. For the quantitative PET/MRI and PET/CT analysis, a region of interest (ROI) was drawn around each lesion and within the contralateral white matter. Lesion to contralateral white matter ratios for relative maximum, mean, and median were calculated. For pMRI, lesion ROI was drawn on the cerebral blood volume (CBV) maps and histogram metrics were calculated. Diagnostic performance for each metric was assessed using receiver operating characteristic curve analysis and area under curve (AUC) was calculated. In 24 patients, 28 lesions were identified. For PET/MRI, relative mean ≥ 1.31 resulted in AUC of .94 with both sensitivity and negative predictive values (NPVs) of 100%. For pMRI, CBV max ≥3.32 yielded an AUC of .94 with both sensitivity and NPV measuring 100%. The joint model utilizing r-mean (PET/MRI) and CBV mode (pMRI) resulted in AUC of 1.0. Our study demonstrates that quantitative PET/MRI parameters in combination with DSC pMRI provide the best diagnostic utility in distinguishing RN from TR in treated GBMs. © 2017 The Authors. Journal of Neuroimaging published by Wiley Periodicals, Inc. on behalf of American Society of Neuroimaging.

Clinical potential and limitation of MRI for degenerative lumbar spinal diseases. Comparison of MRI, myelography, CT and selective nerve root infiltration

Energy Technology Data Exchange (ETDEWEB)

Seki, Michihiro; Kikuchi, Shinichi [Fukushima Medical Coll. (Japan)

1994-12-01

To assess the clinical potential and limitations of magnetic resonance imaging (MRI) in degenerative lumbar spinal diseases, the findings of MR imaging were compared with those of myelography and CT. The subjects were 80 patients with intervertebral disc herniation (46), spondylosis (28), degenerative spondylolisthesis (5), and spondylolysis (one). There was a good correlation between sagittal MRI (T1-weighted images) and myelography in measuring the anteroposterior diameter and the compression rate of the injured dural canal in all disease categories. However, MRI was inferior, irrespective of sagittal and coronal images, to myelography in detecting blocking of the dural canal and intradural findings such as redundant nerve roots. MRI was inferior to selective nerve root infiltration in visualizing the compression of the nerve root, irrespective of diseases; however, there was no difference in abnormal findings of the running of nerve root between the two modalities. Transverse MRI was superior to CT in visualizing the nerve root. Thus, MRI alone is insufficient for the diagnosis of degenerative lumbar spinal diseases, and the other modalities should be supplementary for pathophysiological understanding of these diseases. (N.K.).

Clinical potential and limitation of MRI for degenerative lumbar spinal diseases. Comparison of MRI, myelography, CT and selective nerve root infiltration

International Nuclear Information System (INIS)

Seki, Michihiro; Kikuchi, Shinichi

1994-01-01

To assess the clinical potential and limitations of magnetic resonance imaging (MRI) in degenerative lumbar spinal diseases, the findings of MR imaging were compared with those of myelography and CT. The subjects were 80 patients with intervertebral disc herniation (46), spondylosis (28), degenerative spondylolisthesis (5), and spondylolysis (one). There was a good correlation between sagittal MRI (T1-weighted images) and myelography in measuring the anteroposterior diameter and the compression rate of the injured dural canal in all disease categories. However, MRI was inferior, irrespective of sagittal and coronal images, to myelography in detecting blocking of the dural canal and intradural findings such as redundant nerve roots. MRI was inferior to selective nerve root infiltration in visualizing the compression of the nerve root, irrespective of diseases; however, there was no difference in abnormal findings of the running of nerve root between the two modalities. Transverse MRI was superior to CT in visualizing the nerve root. Thus, MRI alone is insufficient for the diagnosis of degenerative lumbar spinal diseases, and the other modalities should be supplementary for pathophysiological understanding of these diseases. (N.K.)

Combined use of 18F-FDG PET/CT and MRI for response monitoring of breast cancer during neoadjuvant chemotherapy

International Nuclear Information System (INIS)

Pengel, Kenneth E.; Loo, Claudette E.; Koolen, Bas B.; Vogel, Wouter V.; Valdes Olmos, Renato A.; Wesseling, Jelle; Lips, Esther H.; Rutgers, Emiel J.T.; Vrancken Peeters, Marie Jeanne T.F.D.; Rodenhuis, Sjoerd; Gilhuijs, Kenneth G.A.

2014-01-01

To explore the potential complementary value of PET/CT and dynamic contrast-enhanced MRI in predicting pathological response to neoadjuvant chemotherapy (NAC) of breast cancer and the dependency on breast cancer subtype. We performed 18 F-FDG PET/CT and MRI examinations before and during NAC. The imaging features evaluated on both examinations included baseline and changes in 18 F-FDG maximum standardized uptake value (SUVmax) on PET/CT, and tumour morphology and contrast uptake kinetics on MRI. The outcome measure was a (near) pathological complete response ((near-)pCR) after surgery. Receiver operating characteristic curves with area under the curve (AUC) were used to evaluate the relationships between patient, tumour and imaging characteristics and tumour responses. Of 93 patients, 43 achieved a (near-)pCR. The responses varied among the different breast cancer subtypes. On univariate analysis the following variables were significantly associated with (near-)pCR: age (p = 0.033), breast cancer subtype (p < 0.001), relative change in SUVmax on PET/CT (p < 0.001) and relative change in largest tumour diameter on MRI (p < 0.001). The AUC for the relative reduction in SUVmax on PET/CT was 0.78 (95 % CI 0.68-0.88), and for the relative reduction in tumour diameter at late enhancement on MRI was 0.79 (95 % CI 0.70-0.89). The AUC increased to 0.90 (95 % CI 0.83-0.96) in the final multivariate model with PET/CT, MRI and breast cancer subtype combined (p = 0.012). PET/CT and MRI showed comparable value for monitoring response during NAC. Combined use of PET/CT and MRI had complementary potential. Research with more patients is required to further elucidate the dependency on breast cancer subtype. (orig.)

Detection of hepatocellular carcinoma by Gd-EOB-DTPA-enhanced liver MRI: Comparison with triple phase 64 detector row helical CT

International Nuclear Information System (INIS)

Akai, Hiroyuki; Kiryu, Shigeru; Matsuda, Izuru; Satou, Jirou; Takao, Hidemasa; Tajima, Taku; Watanabe, Yasushi; Imamura, Hiroshi; Kokudo, Norihiro; Akahane, Masaaki; Ohtomo, Kuni

2011-01-01

Purpose: To compare the diagnostic performance of Gd-EOB-DTPA-enhanced MRI with that of triple phase 64-MDCT in the detection of hepatocellular carcinoma (HCC). Patients and methods: Thirty-four patients with 52 surgically proven lesions underwent Gd-EOB-DTPA-enhanced MRI and triple phase 64-MDCT. Two observers independently evaluated MR and CT imaging on a lesion-by-lesion basis. Sensitivity, positive and negative predictive values and reproducibility were evaluated. The diagnostic accuracy of each modality was assessed with alternative-free response receiver operating characteristic (ROC) analysis. Results: Both observers showed higher sensitivity in detecting lesions with MRI compared to CT, however, only the difference between the two imaging techniques for observer 2 was significant (P = 0.034). For lesions 1 cm or smaller, MRI and CT showed equal sensitivity (both 62.5%) with one observer, and MRI proved superior to CT with the other observer (MRI 75% vs. CT 56.3%), but the latter difference was not significant (P = 0.083). The difference in positive and negative predictive value between the two imaging techniques for each observer was not significant (P > 0.05). The areas under the ROC curve for each observer were 0.843 and 0.861 for MRI vs. 0.800 and 0.833 for CT and the differences were not significant. Reproducibility was higher using MRI for both observers, but the result was not significant (MRI 32/33 vs. CT 29/33, P = 0.083). Conclusion: Gd-EOB-DTPA-enhanced MRI tended to show higher diagnostic accuracy, sensitivity and reproducibility compared to triple phase 64-MDCT in the detection of hepatocellular carcinoma, however statistical significance was not achieved.

Initial observations of electronic medical record usage during CT and MRI interpretation: Frequency of use and impact on workflow.

Science.gov (United States)

Lin, Abraham; Harris, Mitchell; Zalis, Michael

2010-07-01

Electronic medical record (EMR) systems permit integration of contextual nonimaging EMR data into examination interpretation; however, the extra effort required to search and review these nonradiologic data are not well characterized. We assessed the gross frequency and pattern of EMR usage in the interpretation of diagnostic CT and MRI examinations. We defined nonradiologic EMR data as laboratory data, nonimaging specialty report, clinical note, and administrative data not available on PACS. For abdominal, neuroradiologic, and musculoskeletal CT and MRI, we prospectively recorded the time required for image analysis (including prior imaging studies and their reports), nonradiologic EMR use, and initial report drafting by fellows and staff in randomized sessions. We assessed EMR use as a fraction of work activity and according to technique, subspecialty, inpatient status, and radiologist experience. We observed 372 CT and MRI interpretations by 33 radiologists. For CT, radiologists used the EMR in 34% of abdominal, 57% of neuroradiologic, and 38% of musculoskeletal interpretations. For MRI, EMR was used in 73% of abdominal, 56% of neuroradiologic, and 33% of musculoskeletal interpretations. For CT, EMR usage comprised 18%, 14%, and 18% of diagnostic effort (image analysis plus EMR use) for abdominal, neuroradiologic, and musculoskeletal interpretations, respectively; for MRI, EMR usage comprised 21%, 16%, and 15% of diagnostic effort for abdominal, neuroradiologic, and musculoskeletal interpretations, respectively. Frequency of EMR use was significantly greater for neuroradiology CT and abdominal MRI (p < 0.05, Fisher's test). EMR usage was not consistently related to inpatient status for CT or radiologist experience. For CT and MRI interpretation, EMR usage is frequent and comprises a significant fraction of diagnostic effort.

Tracer kinetic modelling of tumour angiogenesis based on dynamic contrast-enhanced CT and MRI measurements

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Brix, Gunnar [Federal Office for Radiation Protection, Department of Medical and Occupational Radiation Protection, Oberschleissheim (Germany); Bundesamt fuer Strahlenschutz (BfS), Abteilung fuer medizinischen und beruflichen Strahlenschutz, Oberschleissheim (Germany); Griebel, Juergen [Federal Office for Radiation Protection, Department of Medical and Occupational Radiation Protection, Oberschleissheim (Germany); Kiessling, Fabian [RWTH-Aachen University, Department of Experimental Molecular Imaging, Aachen (Germany); Wenz, Frederik [University Medical Center Mannheim, University of Heidelberg, Department of Radiation Oncology, Mannheim (Germany)

2010-08-15

Technical developments in both magnetic resonance imaging (MRI) and computed tomography (CT) have helped to reduce scan times and expedited the development of dynamic contrast-enhanced (DCE) imaging techniques. Since the temporal change of the image signal following the administration of a diffusible, extracellular contrast agent (CA) is related to the local blood supply and the extravasation of the CA into the interstitial space, DCE imaging can be used to assess tissue microvasculature and microcirculation. It is the aim of this review to summarize the biophysical and tracer kinetic principles underlying this emerging imaging technique offering great potential for non-invasive characterization of tumour angiogenesis. In the first part, the relevant contrast mechanisms are presented that form the basis to relate signal variations measured by serial CT and MRI to local tissue concentrations of the administered CA. In the second part, the concepts most widely used for tracer kinetic modelling of concentration-time courses derived from measured DCE image data sets are described in a consistent and unified manner to highlight their particular structure and assumptions as well as the relationships among them. Finally, the concepts presented are exemplified by the analysis of representative DCE data as well as discussed with respect to present and future applications in cancer diagnosis and therapy. Depending on the specific protocol used for the acquisition of DCE image data and the particular model applied for tracer kinetic analysis of the derived concentration-time courses, different aspects of tumour angiogenesis can be quantified in terms of well-defined physiological tissue parameters. DCE imaging offers promising prospects for improved tumour diagnosis, individualization of cancer treatment as well as the evaluation of novel therapeutic concepts in preclinical and early-stage clinical trials. (orig.)

CT and MRI findings of Creutzfeldt-Jakob disease in the early stage. The usefulness of diffusion-weighted images

International Nuclear Information System (INIS)

Ukisu, Ryutaro; Kushihashi, Tamio; Gokan, Takehiko

2001-01-01

To detect subtle CT and MRI features of Creutzfeldt-Jacob disease (CJD) in the early stage is important to prevent a human-to-human transmission. This study included 10 patients of CJD who underwent CT and/or MRI in its early stage. CT, T1- and T2-weighted MRI, DWI, and FLAIR images were obtained in 10, 6, 4, and 2 patients respectively. On DWI, abnormal hyperintensities were observed in both cerebral cortex, and in basal ganglia in all patients. On FLAIR images, abnormal hyperintensies were observed in one patient. Detection of abnormal intensities may be possible in the early stage of CJD using MRI, particularly with DWI. (author)

CT and MRI findings of Creutzfeldt-Jakob disease in the early stage. The usefulness of diffusion-weighted images

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Ukisu, Ryutaro; Kushihashi, Tamio; Gokan, Takehiko [Showa Univ., Tokyo (Japan). School of Medicine] [and others

2001-02-01

To detect subtle CT and MRI features of Creutzfeldt-Jacob disease (CJD) in the early stage is important to prevent a human-to-human transmission. This study included 10 patients of CJD who underwent CT and/or MRI in its early stage. CT, T1- and T2-weighted MRI, DWI, and FLAIR images were obtained in 10, 6, 4, and 2 patients respectively. On DWI, abnormal hyperintensities were observed in both cerebral cortex, and in basal ganglia in all patients. On FLAIR images, abnormal hyperintensies were observed in one patient. Detection of abnormal intensities may be possible in the early stage of CJD using MRI, particularly with DWI. (author)

Is it possible to make a diagnosis of idiopathic normal pressure hydrocephalus on MRI/CT?

International Nuclear Information System (INIS)

Ishikawa, Masatsune; Suzuki, Takayuki; Ohwaki, Hisayuki; Matsumoto, Atsuhito

2006-01-01

In 2004, Japanese guidelines for idiopathic normal pressure hydrocephalus (iNPH) were created to diagnose it more precisely and treat it more effectively. The guidelines suggested the importance of a tight cerebrospinal fluid (CSF) space at the high convexity area. We reviewed MRI/CT findings in 38 cases of probable iNPH during Jan. 1998 to Dec. 2003. We noted the tightness in the interhemispheric fissure on axial MRI/CT view. Thirty-three cases were shunt-responsive among 38 cases (shunt effectiveness: 86.8%). MRI/CT findings of iNPH on axial view were classified into typical, almost typical and atypical. Major findings of typical cases showed: 1) ventricular dilatation, 2) tight interhemispheric fissure, 3) dilated Sylvian fissure. Almost all of the typical cases were a little bit questionable on findings for 2) and/or 3). Atypical cases showed an absence of finding 2) or showed aqueductal stenosis. Among 33 the shunt-responding cases, ten cases (30%) were typical, 16 cases (49%) were almost typical and seven cases were atypical. Among the 5 cases of non-responders, they were divided into 2, 2 and 1 cases, respectively. Atypical cases included 2 cases of aqueductal stenosis and 5 cases of open interhemispheric fissure; the latter were difficult to differentiate form brain atrophy. Thus, about 80% of iNPH cases could be diagnosed or highly suspected on axial MRI/CT findings. Although MRI/CT findings were not definitive for making a diagnosis of iNPH, they were highly useful to idenitify patients for a CSF tap test. (author)

Hyperplastic callus formation in osteogenesis imperfecta: CT and MRI findings

International Nuclear Information System (INIS)

Rieker, O.; Kreitner, K.F.; Karbowski, A.

1998-01-01

Hyperplastic callus formation is a noteworthy condition in patients with osteogenesis imperfecta because it often mimicks osteosarcoma on radiography. The findings of CT and MRI in hyperplastic callus formation have not been reported. In the presented case, MRI demonstrated contrast enhancement and edema of the surrounding soft tisssue, consistent with benign as well as malignant disease. Computed tomography showed a calcified rim of the lesion which may be a useful feature to rule out osteosarcoma in this condition. (orig.)

CT, MRI and MRS of Epstein-Barr virus infection: case report

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Cecil, K.M.; Jones, B.V.; Hedlund, G.L. [Dept. of Radiology, Children' s Hospital Medical Center, Cincinnati, OH (United States); Williams, S. [Dept. of Neurology, Children' s Hospital Medical Center, Cincinnati, OH (United States)

2000-08-01

We report MRI and proton MR spectroscopy (MRS) findings in a 12-month-old girl with Epstein-Barr virus encephalitis. CT and MRI showed focal lesions in the basal ganglia. MRS of the lesions showed decreased N-acetyl aspartate and elevation of some amino acids, indicating an infectious rather than ischemic etiology. This case illustrates the use of MRS to narrow differential diagnosis. (orig.)

CT, MRI and MRS of Epstein-Barr virus infection: case report

International Nuclear Information System (INIS)

Cecil, K.M.; Jones, B.V.; Hedlund, G.L.; Williams, S.

2000-01-01

We report MRI and proton MR spectroscopy (MRS) findings in a 12-month-old girl with Epstein-Barr virus encephalitis. CT and MRI showed focal lesions in the basal ganglia. MRS of the lesions showed decreased N-acetyl aspartate and elevation of some amino acids, indicating an infectious rather than ischemic etiology. This case illustrates the use of MRS to narrow differential diagnosis. (orig.)

Comparison of SPECT/CT and MRI in diagnosing symptomatic lesions in ankle and foot pain patients: diagnostic performance and relation to lesion type.

Science.gov (United States)

Ha, Seunggyun; Hong, Sung Hwan; Paeng, Jin Chul; Lee, Dong Yeon; Cheon, Gi Jeong; Arya, Amitabh; Chung, June-Key; Lee, Dong Soo; Kang, Keon Wook

2015-01-01

The purpose of this study was to compare the diagnostic performance of SPECT/CT and MRI in patients with ankle and foot pain, with regard to the lesion types. Fifty consecutive patients with ankle and foot pain, who underwent 99mTc-MDP SPECT/CT and MRI, were retrospectively enrolled in this study. Symptomatic lesions were determined based on clinical examination and response to treatment. On MRI and SPECT/CT, detected lesions were classified as bone, ligament/tendon, and joint lesions. Uptake on SPECT/CT was assessed using a 4-grade system. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of SPECT/CT and MRI were evaluated in all detected lesions and each lesion type. Diagnostic value of uptake grade was analyzed using receiver-operating characteristics (ROC) curve analysis, and diagnostic performance was compared using Chi-square or McNemar tests. In overall lesions, the sensitivity, PPV and NPV of SPECT/CT for symptomatic lesions were 93%, 56%, 91%, and they were 98%, 48%, 95% for MRI. There was no significant difference between SPECT/CT and MRI. However, the specificity of SPECT/CT was significantly higher than that of MRI (48% versus 24%, P = 0.016). Uptake grade on SPECT/CT was significantly higher in symptomatic lesions (P diagnostic performance for symptomatic lesions in ankle and foot pain patients. SPECT/CT and MRI exhibit different diagnostic specificity in different lesion types. SPECT/CT may be used as a complementary imaging method to MRI for enhancing diagnostic specificity.

MRI and brain spect findings in patients with unilateral temporal lobe epilepsy and normal CT scan

Directory of Open Access Journals (Sweden)

P.G. Carrilho

1994-06-01

Full Text Available 26 patients with temporal lobe epilepsy clinically documented by several abnormal interictal surface EEGs with typical unitemporal epileptiform activity and a normal CT scan were studied. Interictal99mTC HMPAO brain SPECT and MRI were performed in all subjects. Abnormalities were shown in 61.5% of MRI (n=16 and 65.4% of SPECT (n=17. Hippocampal atrophy associated to a high signal on T2-weighted MRI slices suggesting mesial temporal sclerosis was the main finding (n=12; 75% of abnormal MRI. MRI correlated well to surface EEG in 50% (n=13. There was also a good correlation between MRI and SPECT in 30.7% (n=8. SPECT and EEG were in agreement in 57.7% (n=l5. MRI, SPECT and EEG were congruent in 26.9% (n=7. These results support the usefulness of interictal brain SPECT and MRI in detecting lateralized abnormalities in temporal lobe epilepsy. On the other hand, in two cases, interictal SPECT correlated poorly with surface EEG. This functional method should not be used isolately in the detection of temporal lobe foci. MRI is more useful than CT as a neuroimaging technique in temporal lobe epilepsy. It may detect small structural lesions and mesial temporal lobe sclerosis which are not easily seen with traditional CT scanning.

Serial MRI findings of osteoporotic vertebral fractures in the thoracic and lumbar spine

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Hamada, Yoshitaka; Henmi, Tatsuhiko; Sakamoto, Rintaro; Hiasa, Masahiko [Health Insurance Naruto Hospital, Tokushima (Japan)

1998-12-01

The prognosis of osteoporotic vertebral fractures in the thoracic and lumbar spine was studied by serial MRI findings. This study covered 80 vertebrae in 69 patients treated conservatively and followed-up for more than six months (23 males and 46 females, average age 70 yrs). Group A, characterized by poor diagnostic imaging, consisted of patients who had both severely collapsed vertebra which was progressive in the lateral roentgenogram and delayed improvement in MRI signal intensities. Group B, consisting of poor clinical prognosis, comprised patients with persistent back pain. The predictive factors for Group A were found to be T{sub 1}-low finding over the entire vertebra within one month after injury and fractures of Th{sub 12} or L{sub 1} vertebra. Areas of T{sub 1}-low and T{sub 2}-low intensity adjacent to the vertebral disc presented no improvement in signal intensity and often caused persistent back pain. (author)

The comparative study of lumbar disc disruption with MRI and CT discography

International Nuclear Information System (INIS)

Chen Xingcan; Liu Naifang; Li Xiaohong; Xu Wengen; Zou Qing; Yang Yonghong

2005-01-01

Objective: To compare MRI with CT discography (CTD) for diagnostic assessment of lumbar disc disruption. Methods: Paired comparative examination in 16 patients with chronic lower back pain without radicular pain and no disc herniation was conducted using CT or MRI. The standard of CTD classification and positive disc was formulated and the correlation between the induced lower back pain and dosage used in CTD was observed. Results: For a total of 21 discs in the 16 patients, CTD showed the disc as type 2 in 12 discs and type 5 in 1 disc with 13 positive discs, while MRI only showed the high-intensity zone of posterior annulus in 6 discs as the indirect sign of disc disruption and disc degeneration in 7 discs. Conclusion: CTD was the only method for showing the direct sign of disc disruption. The induced lower back pain was related with the type of disc disruption. MRI can show some of the indirect signs of disc disruption and CTD can show the direct sign of disc disruption. (authors)

Mediastinal and heart wall invasion by actinomycosis: CT and MRI appearances

International Nuclear Information System (INIS)

Fisch, C.; Schmutz, G.R.; Benko, A.J.; Kastler, B.

1994-01-01

Widespread use of antibiotics facilitates the development of some uncommon chronic infections such as actinomycosis. The clinical and radiographic findings overlap those of other inflammatory and neoplastic conditions. With a review of the literature, we report the CT and MRI findings in a case of thoracic actinomycosis, presenting with right ventricular failure caused by heart involvement. CT was helpful in identifying the mediastinal extent of the disease and in demonstrating the absence of pulmonary involvement. MRI, however, offered complementary information, especially in assessing heart involvement without the need for intravenous contrast media. On T2-weighted images the mediastinal process was noted to be of relatively low signal intensity, possibly indicating its benign nature. The association with heart involvement was suggestive of thoracic actinomycosis. (orig.)

An image acquisition and registration strategy for the fusion of hyperpolarized helium-3 MRI and x-ray CT images of the lung

Science.gov (United States)

Ireland, Rob H.; Woodhouse, Neil; Hoggard, Nigel; Swinscoe, James A.; Foran, Bernadette H.; Hatton, Matthew Q.; Wild, Jim M.

2008-11-01

The purpose of this ethics committee approved prospective study was to evaluate an image acquisition and registration protocol for hyperpolarized helium-3 magnetic resonance imaging (3He-MRI) and x-ray computed tomography. Nine patients with non-small cell lung cancer (NSCLC) gave written informed consent to undergo a free-breathing CT, an inspiration breath-hold CT and a 3D ventilation 3He-MRI in CT position using an elliptical birdcage radiofrequency (RF) body coil. 3He-MRI to CT image fusion was performed using a rigid registration algorithm which was assessed by two observers using anatomical landmarks and a percentage volume overlap coefficient. Registration of 3He-MRI to breath-hold CT was more accurate than to free-breathing CT; overlap 82.9 ± 4.2% versus 59.8 ± 9.0% (p < 0.001) and mean landmark error 0.75 ± 0.24 cm versus 1.25 ± 0.60 cm (p = 0.002). Image registration is significantly improved by using an imaging protocol that enables both 3He-MRI and CT to be acquired with similar breath holds and body position through the use of a birdcage 3He-MRI body RF coil and an inspiration breath-hold CT. Fusion of 3He-MRI to CT may be useful for the assessment of patients with lung diseases.

Use of dynamic images in radiology education: Movies of CT and MRI in the anatomy classroom.

Science.gov (United States)

Jang, Hye Won; Oh, Chang-Seok; Choe, Yeon Hyeon; Jang, Dong Su

2018-04-19

Radiology education is a key component in many preclinical anatomy courses. However, the reported effectiveness of radiology education within such anatomy classrooms has varied. This study was conducted to determine if a novel educational method using dynamic images of movies of computed tomography (CT) and magnetic resonance imaging (MRI) was effective in radiology education during a preclinical anatomy course, aided by clay modeling, specific hand gestures (digit anatomy), and reports from dissection findings uploaded to the anatomy course website (digital reports). Feedback surveys using a five-point Likert scale were administered to better clarify students' opinions regarding their understanding of CT and MRI of anatomical structures, as well as to determine if such preclinical radiology education was helpful in their clinical studies. After completion of the anatomy course taught with dynamic images of CT and MRI, most students demonstrated an adequate understanding of basic CT and MR images. Additionally, students in later clinical years generally believed that their study of radiologic images during the preclinical anatomy course was helpful for their clinical studies and clerkship rotations. Moreover, student scores on imaging anatomy examinations demonstrated meaningful improvements in performance after using dynamic images from movies of CT and MRI. Anat Sci Educ. © 2018 American Association of Anatomists. © 2018 American Association of Anatomists.

Thoracic endometriosis syndrome: CT and MRI features

International Nuclear Information System (INIS)

Rousset, P.; Rousset-Jablonski, C.; Alifano, M.; Mansuet-Lupo, A.; Buy, J.-N.; Revel, M.-P.

2014-01-01

Thoracic endometriosis is considered to be rare, but is the most frequent form of extra-abdominopelvic endometriosis. Thoracic endometriosis syndrome affects women of reproductive age. Diagnosis is mainly based on clinical findings, which can include catamenial pneumothorax and haemothorax, non-catamenial endometriosis-related pneumothorax, catamenial haemoptysis, lung nodules, and isolated catamenial chest pain. Symptoms are typically cyclical and recurrent, with a right-sided predominance. Computed tomography (CT) is the first-line imaging method, but is poorly specific; therefore, its main role is to rule out other pulmonary diseases. However, in women with a typical clinical history, some key CT findings may help to confirm this often under-diagnosed syndrome. MRI can also assist with the diagnosis, by showing signal changes typical of haemorrhage within diaphragmatic or pleural lesions

Confidence in Assessment of Lumbar Spondylolysis Using Three-Dimensional Volumetric T2-Weighted MRI Compared With Limited Field of View, Decreased-Dose CT.

Science.gov (United States)

Delavan, Joshua Adam; Stence, Nicholas V; Mirsky, David M; Gralla, Jane; Fadell, Michael F

2016-07-01

Limited z-axis-coverage computed tomography (CT) to evaluate for pediatric lumbar spondylolysis, altering the technique such that the dose to the patient is comparable or lower than radiographs, is currently used at our institution. The objective of the study was to determine whether volumetric 3-dimensional fast spin echo magnetic resonance imaging (3D MRI) can provide equal or greater diagnostic accuracy compared with limited CT in the diagnosis of pediatric lumbar spondylolysis without ionizing radiation. Volumetric 3D MRI can provide equal or greater diagnostic accuracy compared with low-dose CT for pediatric lumbar spondylolysis without ionizing radiation. Clinical review. Level 2. Three pediatric neuroradiologists evaluated 2-dimensional (2D) MRI, 2D + 3D MRI, and limited CT examinations in 42 pediatric patients who obtained imaging for low back pain and suspected spondylolysis. As there is no gold standard for the diagnosis of spondylolysis besides surgery, interobserver agreement and degree of confidence were compared to determine which modality is preferable. Decreased-dose CT provided a greater level of agreement than 2D MRI and 2D + 3D MRI. The kappa for rater agreement with 2D MRI, 2D + 3D MRI, and CT was 0.19, 0.32, and 1.0, respectively. All raters agreed in 31%, 40%, and 100% of cases with 2D MRI, 2D + 3D MRI, and CT. Lack of confidence was significantly lower with CT (0%) than with 2D MRI (30%) and 2D + 3D MRI (25%). For diagnosing spondylolysis, radiologist agreement and confidence trended toward improvement with the addition of a volumetric 3D MRI sequence to standard 2D MRI sequences compared with 2D MRI alone; however, agreement and confidence remain significantly greater using decreased-dose CT when compared with either MRI acquisition. Decreased-dose CT of the lumbar spine remains the optimal examination to confirm a high suspicion of spondylolysis, with dose essentially equivalent to radiographs. If clinical symptoms are not classic for

TU-H-CAMPUS-JeP2-02: Interobserver Variability of CT, PET-CT and MRI Based Primary Tumor Delineation for Lung Cancer

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Karki, K; Hugo, G; Saraiya, S; Jan, N; Schuster, J; Schutzer, M; Fahrner, L; Groves, R; Ford, J; Weiss, E [Virginia Commonwealth University, Richmond, VA (United States)

2016-06-15

Purpose: Target delineation in lung cancer radiotherapy has, in general, large variability. MRI has so far not been investigated in detail for lung cancer delineation variability. The purpose of this study is to investigate delineation variability for lung tumors using MRI and compare it to CT alone and PET-CT based delineations. Methods: Seven physicians delineated the primary tumor volumes of nine patients for the following scenarios: (1) CT only; (2) post-contrast T1-weighted MRI registered with diffusion-weighted MRI; and (3) PET-CT fusion images. To compute interobserver variability, the median surface was generated from all observers’ contours and used as the reference surface. A single physician labeled the interface types (tumor to lung, atelectasis (collapsed lung), hilum, mediastinum, or chest-wall) on the median surface. Volume variation (normalized to PET-CT volume), minimum distance (MD), and bidirectional local distance (BLD) between individual observers’ contours and the reference contour were measured. Results: CT- and MRI-based normalized volumes were 1.61±0.76 (mean±SD) and 1.38±0.44, respectively, both significantly larger than PET-CT (p<0.05, paired t-test). The overall uncertainty (root mean square of SD values over all points) of both BLD and MD measures of the observers for the interfaces were not significantly different (p>0.05, two-samples t-test) for all imaging modalities except between tumor-mediastinum and tumor-atelectasis in PET-CT. The largest mean overall uncertainty was observed for tumor-atelectasis interface, the smallest for tumor-mediastinum and tumor-lung interfaces for all modalities. The whole tumor uncertainties for both BLD and MD were not significantly different between any two modalities (p>0.05, paired t-test). Overall uncertainties for the interfaces using BLD were similar to using MD. Conclusion: Large volume variations were observed between the three imaging modalities. Contouring variability appeared to

Diagnosis of non-osseous spinal metastatic disease: the role of PET/CT and PET/MRI.

Science.gov (United States)

Batouli, Ali; Braun, John; Singh, Kamal; Gholamrezanezhad, Ali; Casagranda, Bethany U; Alavi, Abass

2018-06-01

The spine is the third most common site for distant metastasis in cancer patients with approximately 70% of patients with metastatic cancer having spinal involvement. Positron emission tomography (PET), combined with computed tomography (CT) or magnetic resonance imaging (MRI), has been deeply integrated in modern clinical oncology as a pivotal component of the diagnostic work-up of patients with cancer. PET is able to diagnose several neoplastic processes before any detectable morphological changes can be identified by anatomic imaging modalities alone. In this review, we discuss the role of PET/CT and PET/MRI in the diagnostic management of non-osseous metastatic disease of the spinal canal. While sometimes subtle, recognizing such disease on FDG PET/CT and PET/MRI imaging done routinely in cancer patients can guide treatment strategies to potentially prevent irreversible neurological damage.

Ability of 18F-DOPA PET/CT and fused 18F-DOPA PET/MRI to assess striatal involvement in paediatric glioma

International Nuclear Information System (INIS)

Morana, Giovanni; Severino, Mariasavina; Tortora, Domenico; Rossi, Andrea; Puntoni, Matteo; Garre, Maria Luisa; Massollo, Michela; Naseri, Merhdad; Piccardo, Arnoldo; Lopci, Egesta

2016-01-01

To assess the diagnostic performance of 18 F-DOPA PET/CT and fused 18 F-DOPA PET/MRI in detecting striatal involvement in children with gliomas. This retrospective study included 28 paediatric patients referred to our institution for the presence of primary, residual or recurrent glioma (12 boys, 16 girls; mean age 10.7 years) and investigated with 18 F-DOPA PET/CT and brain MRI. Fused 18 F-DOPA PET/MR images were obtained and compared with PET/CT and MRI images. Accuracy, sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) for striatal involvement were calculated for each diagnostic tool. Univariate and multivariate logistic analyses were applied to evaluate the associations between 18 F-DOPA PET/CT and fused 18 F-DOPA PET/MRI diagnostic results and tumour uptake outside the striatum, grade, dimension and site of striatal involvement (ventral and/or dorsal). Accuracy, sensitivity, specificity, PPV, and NPV were 100 % for MRI, 93 %, 89 %, 100 %, 100 % and 82 % for 18 F-DOPA PET/MRI, and 75 %, 74 %, 78 %, 88 % and 58 % for 18 F-DOPA PET/CT, respectively. 18 F-DOPA PET/MRI showed a trend towards higher accuracy compared with 18 F-DOPA PET/CT (p = 0.06). MRI showed significantly higher accuracy compared with 18 F-DOPA PET/CT (p = 0.01), but there was no significant difference between MRI and 18 F-DOPA PET/MRI. Both univariate and multivariate logistic analyses showed a significant association (OR 8.0 and 7.7, respectively) between the tumour-to-normal striatal uptake (T/S) ratio and the diagnostic ability of 18 F-DOPA PET/CT (p = 0.03). A strong significant association was also found between involvement of the dorsal striatum and the 18 F-DOPA PET/CT results (p = 0.001), with a perfect prediction of involvement of the dorsal striatum by 18 F-DOPA PET/MRI. Physiological striatal 18 F-DOPA uptake does not appear to be a main limitation in the evaluation of basal ganglia involvement. 18 F-DOPA PET/CT correctly detected

Focal cortical dysplasia of the temporal lobe with late-onset partial epilepsy: serial quantitative MRI

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Rademacher, J.; Seitz, R.J. [Department of Neurology, Heinrich-Heine University Duesseldorf (Germany); Aulich, A. [Department of Radiology, Heinrich-Heine University, Duesseldorf (Germany); Reifenberger, G. [Department of Neuropathology, Heinrich-Heine University, Duesseldorf (Germany); Kiwit, J.C.W. [Department of Neurosurgery, Heinrich-Heine University, Duesseldorf (Germany); Langen, K.J.; Schmidt, D. [Institute of Medicine, Research Center Juelich, Heinrich-Heine University, Duesseldorf (Germany)

2000-06-01

We describe serial studies of focal cortical dysplasia causing temporal lobe seizures and progressive aphasia in a 54-year-old woman. Initially, MRI volumetry of the temporal lobes showed significant left cortical thickening corresponding to an elevated aminoacid uptake in the left temporoparietal and inferior frontal cortex on SPECT using 3-[{sup 123}I]iodo-{alpha}-methyl-l-tyrosine (IMT). After 1 year there was severe shrinkage of the left temporal lobe, possibly the result of recurrent complex partial seizures. (orig.)

Focal cortical dysplasia of the temporal lobe with late-onset partial epilepsy: serial quantitative MRI

International Nuclear Information System (INIS)

Rademacher, J.; Seitz, R.J.; Aulich, A.; Reifenberger, G.; Kiwit, J.C.W.; Langen, K.J.; Schmidt, D.

2000-01-01

We describe serial studies of focal cortical dysplasia causing temporal lobe seizures and progressive aphasia in a 54-year-old woman. Initially, MRI volumetry of the temporal lobes showed significant left cortical thickening corresponding to an elevated aminoacid uptake in the left temporoparietal and inferior frontal cortex on SPECT using 3-[ 123 I]iodo-α-methyl-l-tyrosine (IMT). After 1 year there was severe shrinkage of the left temporal lobe, possibly the result of recurrent complex partial seizures. (orig.)

Hyperplastic callus formation in osteogenesis imperfecta: CT and MRI findings

Energy Technology Data Exchange (ETDEWEB)

Rieker, O.; Kreitner, K.F. [Klinik fuer Radiologie, Johannes-Gutenberg-Univ. Mainz (Germany); Karbowski, A. [Orthopaedische Abtl., Krankenhaus der Augustinerinnen, Koeln (Germany)

1998-09-01

Hyperplastic callus formation is a noteworthy condition in patients with osteogenesis imperfecta because it often mimicks osteosarcoma on radiography. The findings of CT and MRI in hyperplastic callus formation have not been reported. In the presented case, MRI demonstrated contrast enhancement and edema of the surrounding soft tisssue, consistent with benign as well as malignant disease. Computed tomography showed a calcified rim of the lesion which may be a useful feature to rule out osteosarcoma in this condition. (orig.) With 2 figs., 18 refs.

Ultrasound, CT and MRI Appearances of a Rare Symptomatic Laryngeal Chondrometaplasia: A Case Report

International Nuclear Information System (INIS)

Lee, Ryan Ka Lok; Hok Yuen, Edmond Yuen; Abdullah, Victor James; Ping Lee, Yolanda Yim; Ahuja, Anil Tejbhan

2015-01-01

Symptomatic laryngeal chondrometaplasia is rare. To the best of our knowledge, there are only few case reports on laryngeal chondrometaplasia. The imaging appearance of this uncommon disease is even more rarely described. There are only two case reports describing its appearances in computed tomography (CT) and magnetic resonance imaging (MRI). Ultrasound (US) features have not been reported so far. This case report is to show the US, CT and MRI features of this disease entity to stress the role of imaging in this disease

DW MRI at 3.0 T versus FDG PET/CT for detection of malignant pulmonary tumors.

Science.gov (United States)

Zhang, Jian; Cui, Long-Biao; Tang, Xing; Ren, Xin-Ling; Shi, Jie-Ran; Yang, Hai-Nan; Zhang, Yan; Li, Zhi-Kui; Wu, Chang-Gui; Jian, Wen; Zhao, Feng; Ti, Xin-Yu; Yin, Hong

2014-02-01

Emerging evidence suggests that diffusion-weighted magnetic resonance imaging (DW MRI) could be useful for tumor detection with N and M staging of lung cancer in place of fluorine 18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT). DW MRI at 3.0 T and FDG PET/CT were performed before therapy in 113 patients with pulmonary nodules. Mean apparent diffusion coefficient (ADC), maximal standardized uptake value (SUVmax ) and Ki-67 scores were assessed. Quantitatively, specificity and accuracy of ADC (91.7 and 92.9%, respectively) were significantly higher than those of SUVmax (66.7 and 77.9% respectively, p 0.05). Qualitatively, sensitivity, specificity and accuracy of DW MRI (96.1, 83.3 and 92.0%, respectively) were also not significantly different from that of FDG PET/CT (88.3, 83.3 and 86.7%, respectively, p > 0.05). Significant negative correlation was found between Ki-67 score and ADC (r = -0.66, p 0.05). In conclusion, quantitative and qualitative assessments for detection of malignant pulmonary tumors with DW MRI at 3.0 T are superior to those with FDG PET/CT. Furthermore, ADC could predict the malignancy of lung cancer. © 2013 UICC.

Comparison of thallium-201 SPET and CT/MRI in the detection of residual/recurrent squamous cell carcinoma of the oral cavity

International Nuclear Information System (INIS)

Lee, Jong-Kang; Tyan, Yeu-Sheng; Huang, Wen-Sheng

2004-01-01

This study was designed to compare the effectiveness of thallium-201 single-photon emission tomography (SPET) and conventional imaging, comprising computed tomography (CT) and magnetic resonance imaging (MRI), in the detection of residual/recurrent squamous cell carcinoma (SCC) of the oral cavity. Thirty-two patients with clinically suspected recurrent SCC of the oral cavity were recruited. All patients underwent 201 Tl SPET and CT or MRI within 2 weeks. The final diagnoses were based on the histology of the biopsy specimen. 201 Tl SPET and CT/MRI both accurately detected 17 of 18 residual/recurrent tumours. CT/MRI yielded eight false-positive studies, whereas 201 Tl SPET successfully excluded all tumours. The sensitivity, specificity, positive and negative predictive values and accuracy of 201 Tl SPET for the detection of recurrent oral SCC were 94%, 100%, 100%, 93% and 97%, respectively. The sensitivity, specificity, positive and negative predictive values and accuracy of CT/MRI for the detection of recurrent oral SCC were 94%, 43%, 68%, 86% and 72%, respectively. Thallium-201 SPET is more accurate than conventional imaging (CT or MRI) in differentiating residual/recurrent oral SCC from post-therapy changes. (orig.)

A STUDY ON PERITUMORAL BRAIN EDEMA AROUND MENINGIOMAS BY MRI AND CONTRAST CT

NARCIS (Netherlands)

GO, KG; KAMMAN, RL; WILMINK, JT; MOOYAART, EL

1994-01-01

In the present study upon 9 meningiomas, the volume of peritumoral brain edema was calculated by integration of the cross-sectional edematous areas on serial MRI slices. It was zero in 3 cases and ranged from 11 to 176.4 ml in the other cases. There was disruption of the cortex in all cases, ranging

Diagnosis and dosimetry in differentiated thyroid carcinoma using 124I PET: comparison of PET/MRI vs PET/CT of the neck

International Nuclear Information System (INIS)

Nagarajah, James; Jentzen, Walter; Hartung, Verena; Rosenbaum-Krumme, Sandra; Bockisch, Andreas; Stahl, Alexander; Mikat, Christian; Heusner, Till Alexander; Antoch, Gerald

2011-01-01

This study compares intrinsically coregistered 124 I positron emission tomography (PET) and CT (PET/CT) and software coregistered 124 I PET and MRI (PET/MRI) images for the diagnosis and dosimetry of thyroid remnant tissues and lymph node metastases in patients with differentiated thyroid carcinoma (DTC). After thyroidectomy, 33 high-risk DTC patients (stage III or higher) received 124 I PET/CT dosimetry prior to radioiodine therapy to estimate the absorbed dose to lesions and subsequently underwent a contrast-enhanced MRI examination of the neck. Images were evaluated by two experienced nuclear medicine physicians and two radiologists to identify the lesions and to categorize their presumable provenience, i.e. thyroid remnant tissue (TT), lymph node metastasis (LN) and inconclusive tissue. The categorization and dosimetry of lesions was initially performed with PET images alone (PET only). Subsequently lesions were reassessed including the CT and MRI data. The analyses were performed on a patient and on a lesion basis. Patient-based analyses showed that 26 of 33 (79%) patients had at least one lesion categorized as TT on PET only. Of these patients, 11 (42%) and 16 (62%) had a morphological correlate on CT and MRI, respectively, in at least one TT PET lesion. Twelve patients (36%) had at least one lesion classified as LN on PET only. Nine (75%) of these patients had a morphological correlate on both CT and MRI in at least one LN PET lesion. Ten patients (30%) showed at least one lesion on PET only classified as inconclusive. The classification was changed to a clear classification in two patients (two LN) by CT and in four (two TT, two LN) patients by MRI. Lesion-based analyses (n = 105 PET positive lesions) resulted in categorization as TT in 61 cases (58%), 16 (26%) of which had a morphological correlate on CT and 33 (54%) on MRI. A total of 29 lesions (27%) were classified as LN on PET, 18 (62%) of which had a morphological correlate on CT and 24 (83%) on MRI

{sup 18}F{sub F}DG PET in evaluating malignancies compared with CT, MRI and pathology in 58 cases

Energy Technology Data Exchange (ETDEWEB)

Li, L. [Air Force General Hospital, Beijing (Switzerland)

2000-07-01

This article discussed the practical application of {sup 18}F-FDG PET imaging techniques to depict, state, or define recurrences for five important malignancies: lung cancer, colorectal and head-and-neck cancer, intracranial malignant glioma and primary or secondary hepatic malignant diseases. And comparisons of {sup 18}F-FDG PET with CT, MRI imaging were addressed specifically. We reviewed our initial experience with 48 malignant and ten non-malignant cases. Among malignant group, 36 cases were confirmed by operation or biopsy, Other ten non-malignant diseases, including brain infarction, post-radiotherapy necrosis or scar and lung abscesses were followed with CT or MRI at least 6 months. All patients received intravenous administration of {sup 18}F-FDG 10-15 mCi, followed by a 40 minutes uptake phase, and subsequent imaged using a Siemens ECAT 931 whole-body scanner with resolution of 4 mm FWHM in the center of the field of view. Filtered back projection reconstruction was used to display attenuated or non-attenuated corrected images. The result of {sup 18}F-FDG PET was retrospectively evaluated to assess the degree of uptake of {sup 18}F-FDG PET in the tumor tissues and compared with CT, MRI and pathology. CT and MRI exam were taken before or after PET study in two weeks. {sup 18}F-FDG PET scans showed a significantly increased FDG metabolism in 47 malignant lesions, The tumor / normal tissue FDG uptake rate were 4.16 {+-}2.11. In 47 cases with neoplasm, {sup 18}F-FDG PET findings were constant with or further confirmed the CT or MRI diagnosis in 35/47 (74.5%) and 12/47 (253%) cases. Another one small intracranial metastasis (<0,6cm), shown on contrast MRI was not displayed by glucose metabolism Otherwise, the tumor/normal tissue FDG uptake rate were 0.86 {+-} 1,46 in ten non-malignant cases. Most of post-radiotherapy cerebral necrosis, which can't be distinguished on both contrast CT and MRI, showed FDG uptake defect. One cerebral infarction, previously

Hybrid imaging for detection of carcinoma of unknown primary: A preliminary comparison trial of whole-body PET/MRI versus PET/CT

International Nuclear Information System (INIS)

Ruhlmann, Verena; Ruhlmann, Marcus; Bellendorf, Alexander; Grueneisen, Johannes; Sawicki, Lino M.; Grafe, Hong; Forsting, Michael; Bockisch, Andreas; Umutlu, Lale

2016-01-01

Highlights: • Both 18F-FDG PET/CT and 18F-FDG PET/MRI provide a comparable diagnostic ability for detection of primary cancer and metastases in CUP-syndrome. • Both imaging methods showed comparably high lesion conspicuity and diagnostic confidence (superior assessment of cervical lesions in PET/MRI). • PET/MRI may serve as a powerful alternative, particularly for therapy monitoring or surveillance considering the long-term cumulative dose. - Abstract: Purpose: The aim of this study is to evaluate and compare the diagnostic potential of integrated whole-body [18F]FDG-PET/MRI to [18F]FDG-PET/CT for detection of a potential primary cancer and metastases in patients suspected for cancer of unknown primary (CUP). Methods: A total of 20 patients (15 male, 5 female, age 53 ± 13 years) suspect for CUP underwent a dedicated head and neck & whole-body [18F]FDG-PET/CT (Biograph mCT 128, Siemens Healthcare) and a subsequent simultaneous [18F]FDG-PET/MRI examination (Biograph mMR, Siemens Healthcare). Two readers rated the datasets (PET/CT; PET/MRI) regarding the detection of the primary cancer and metastases, lesion conspicuity (4-point ordinal scale) and diagnostic confidence (3-point ordinal scale). PET analysis comprised the assessment of maximum standardized uptake values (SUVmax) of all PET-positive lesions using volume of interest (VOI) analysis derived from the PET/CT and PET/MR datasets. All available data considering histology and imaging including prior and clinical follow-up examinations served as reference standard. Statistical analysis included comparison of mean values using Mann-Whitney U test and correlation of SUVmax using Pearson‘s correlation. Results: In 14 out of 20 patients 49 malignant lesions were present. The primary cancer could be correctly identified in 11/20 patients with both PET/CT and PET/MRI. PET/CT enabled the detection of a total 38 metastases, PET/MR respectively of 37 metastases (one lung metastasis <5mm was missed). PET/CT and

Hybrid imaging for detection of carcinoma of unknown primary: A preliminary comparison trial of whole-body PET/MRI versus PET/CT

Energy Technology Data Exchange (ETDEWEB)

Ruhlmann, Verena; Ruhlmann, Marcus; Bellendorf, Alexander [Department of Nuclear Medicine, University Hospital Essen, University Duisburg-Essen, Hufelandstr. 55, 45122 Essen (Germany); Grueneisen, Johannes [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, University Duisburg-Essen, Hufelandstr. 55, 45122 Essen (Germany); Sawicki, Lino M. [Department of Diagnostic and Interventional Radiology, University of Dusseldorf, Moorenstraße 5, 40225 Dusseldorf (Germany); Grafe, Hong [Department of Nuclear Medicine, University Hospital Essen, University Duisburg-Essen, Hufelandstr. 55, 45122 Essen (Germany); Forsting, Michael [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, University Duisburg-Essen, Hufelandstr. 55, 45122 Essen (Germany); Bockisch, Andreas [Department of Nuclear Medicine, University Hospital Essen, University Duisburg-Essen, Hufelandstr. 55, 45122 Essen (Germany); Umutlu, Lale, E-mail: verena.ruhlmann@uk-essen.de [Department of Nuclear Medicine, University Hospital Essen, University Duisburg-Essen, Hufelandstr. 55, 45122 Essen (Germany)

2016-11-15

Highlights: • Both 18F-FDG PET/CT and 18F-FDG PET/MRI provide a comparable diagnostic ability for detection of primary cancer and metastases in CUP-syndrome. • Both imaging methods showed comparably high lesion conspicuity and diagnostic confidence (superior assessment of cervical lesions in PET/MRI). • PET/MRI may serve as a powerful alternative, particularly for therapy monitoring or surveillance considering the long-term cumulative dose. - Abstract: Purpose: The aim of this study is to evaluate and compare the diagnostic potential of integrated whole-body [18F]FDG-PET/MRI to [18F]FDG-PET/CT for detection of a potential primary cancer and metastases in patients suspected for cancer of unknown primary (CUP). Methods: A total of 20 patients (15 male, 5 female, age 53 ± 13 years) suspect for CUP underwent a dedicated head and neck & whole-body [18F]FDG-PET/CT (Biograph mCT 128, Siemens Healthcare) and a subsequent simultaneous [18F]FDG-PET/MRI examination (Biograph mMR, Siemens Healthcare). Two readers rated the datasets (PET/CT; PET/MRI) regarding the detection of the primary cancer and metastases, lesion conspicuity (4-point ordinal scale) and diagnostic confidence (3-point ordinal scale). PET analysis comprised the assessment of maximum standardized uptake values (SUVmax) of all PET-positive lesions using volume of interest (VOI) analysis derived from the PET/CT and PET/MR datasets. All available data considering histology and imaging including prior and clinical follow-up examinations served as reference standard. Statistical analysis included comparison of mean values using Mann-Whitney U test and correlation of SUVmax using Pearson‘s correlation. Results: In 14 out of 20 patients 49 malignant lesions were present. The primary cancer could be correctly identified in 11/20 patients with both PET/CT and PET/MRI. PET/CT enabled the detection of a total 38 metastases, PET/MR respectively of 37 metastases (one lung metastasis <5mm was missed). PET/CT and

CT and MRI assessment of symptomatic organized pancreatic fluid collections and pancreatic duct disruption: an interreader variability study using the revised Atlanta classification 2012.

Science.gov (United States)

Kamal, Ayesha; Singh, Vikesh K; Akshintala, Venkata S; Kawamoto, Satomi; Tsai, Salina; Haider, Maera; Fishman, Elliot K; Kamel, Ihab R; Zaheer, Atif

2015-08-01

Compare CT and MRI for fluid/debris component estimate and pancreatic duct (PD) communication with organized pancreatic fluid collections in acute pancreatitis. Evaluate fat density globules on CT as marker for debris. 29 Patients with 46 collections with CECT and MRI performed ≥4 weeks of symptom onset assessed for necrotizing pancreatitis, estimated percentage of fluid volume and PD involvement by two radiologists on separate occasions. T2WI used as standard for estimated percentage of fluid volume. Presence of fat globules and fluid attenuation on CT was recorded. Spearman rank correlation and kappa statistics were used to assess the correlation between imaging techniques and interreader agreement, respectively. Necrotizing pancreatitis seen on CT in 27 (93%, κ 0.119) vs. 20 (69%, κ 0.748) patients on MRI. CT identified 42 WON and 4 pseudocysts vs. 34 WON, and 12 pseudocysts on MRI. Higher interreader agreement for percentage fluid volume on MRI (κ = 0.55) vs. CT (κ = 0.196). Accuracy of CT in evaluation of percentage fluid volume was 65% using T2WI MRI used as standard. Fat globules identified on CT in 13(65%) out of 20 collections containing collections containing >75% fluid (p = 0.0001). PD involvement confidently excluded on CT in 68% collections vs. 93% on MRI. MRI demonstrates higher reproducibility for fluid to debris component estimation. Fat globules on CT were frequently seen in organized pancreatic fluid collections with large amount of debris. PD disruption more confidently excluded on MRI. This information may be helpful for pre-procedure planning.

MO-F-CAMPUS-J-05: Toward MRI-Only Radiotherapy: Novel Tissue Segmentation and Pseudo-CT Generation Techniques Based On T1 MRI Sequences

Energy Technology Data Exchange (ETDEWEB)

Aouadi, S; McGarry, M; Hammoud, R; Torfeh, T; Perkins, G; Al-Hammadi, N [Hamad Medical Corporation, NCCCR, Doha (Qatar)

2015-06-15

Purpose: To develop and validate a 4 class tissue segmentation approach (air cavities, background, bone and soft-tissue) on T1 -weighted brain MRI and to create a pseudo-CT for MRI-only radiation therapy verification. Methods: Contrast-enhanced T1-weighted fast-spin-echo sequences (TR = 756ms, TE= 7.152ms), acquired on a 1.5T GE MRI-Simulator, are used.MRIs are firstly pre-processed to correct for non uniformity using the non parametric, non uniformity intensity normalization algorithm. Subsequently, a logarithmic inverse scaling log(1/image) is applied, prior to segmentation, to better differentiate bone and air from soft-tissues. Finally, the following method is enrolled to classify intensities into air cavities, background, bone and soft-tissue:Thresholded region growing with seed points in image corners is applied to get a mask of Air+Bone+Background. The background is, afterward, separated by the scan-line filling algorithm. The air mask is extracted by morphological opening followed by a post-processing based on knowledge about air regions geometry. The remaining rough bone pre-segmentation is refined by applying 3D geodesic active contours; bone segmentation evolves by the sum of internal forces from contour geometry and external force derived from image gradient magnitude.Pseudo-CT is obtained by assigning −1000HU to air and background voxels, performing linear mapping of soft-tissue MR intensities in [-400HU, 200HU] and inverse linear mapping of bone MR intensities in [200HU, 1000HU]. Results: Three brain patients having registered MRI and CT are used for validation. CT intensities classification into 4 classes is performed by thresholding. Dice and misclassification errors are quantified. Correct classifications for soft-tissue, bone, and air are respectively 89.67%, 77.8%, and 64.5%. Dice indices are acceptable for bone (0.74) and soft-tissue (0.91) but low for air regions (0.48). Pseudo-CT produces DRRs with acceptable clinical visual agreement to CT

Geographic Distribution of CT, MRI and PET Devices in Japan: A Longitudinal Analysis Based on National Census Data.

Science.gov (United States)

Matsumoto, Masatoshi; Koike, Soichi; Kashima, Saori; Awai, Kazuo

2015-01-01

Japan has the most CT and MRI scanners per unit population in the world; however, the geographic distribution of these technologies is currently unknown. Moreover, nothing is known of the cause-effect relationship between the number of diagnostic imaging devices and their geographic distribution. Data on the number of CT, MRI and PET devices and that of their utilizations in all 1829 municipalities of Japan was generated, based on the Static Survey of Medical Institutions conducted by the government. The inter-municipality equity of the number of devices or utilizations was evaluated with Gini coefficient. Between 2005 and 2011, the number of CT, MRI and PET devices in Japan increased by 47% (8789 to 12945), 19% (5034 to 5990) and 70% (274 to 466), respectively. Gini coefficient of the number of devices was largest for PET and smallest for CT (p for PET-MRI difference geographic distribution of the diagnostic imaging technology in Japan appears to be affected by spatial competition derived from a market force.

'Peripheric' pancreatic cysts: performance of CT scan, MRI and endoscopy according to final pathological examination.

Science.gov (United States)

Duconseil, P; Turrini, O; Ewald, J; Soussan, J; Sarran, A; Gasmi, M; Moutardier, V; Delpero, J R

2015-06-01

To assess the accuracy of pre-operative staging in patients with peripheral pancreatic cystic neoplasms (pPCNs). From 2005 to 2011, 148 patients underwent a pancreatectomy for pPCNs. The pre-operative examination methods of computed tomography (CT), magnetic resonance imaging (MRI), endoscopic ultrasonography (EUS) were compared for their ability to predict the suggested diagnosis accurately, and the definitive diagnosis was affirmed by pathological examination. A mural nodule was detected in 34 patients (23%): only 1 patient (3%) had an invasive pPCN at the final histological examination. A biopsy was performed in 79 patients (53%) during EUS: in 55 patients (70%), the biopsy could not conclude a diagnosis; the biopsy provided the correct and wrong diagnosis in 19 patients (24%) and 5 patients (6%), respectively. A correct diagnosis was affirmed by CT, EUS and pancreatic MRI in 60 (41%), 103 (74%) and 80 (86%) patients (when comparing EUS and MRI; P = 0.03), respectively. The positive predictive values (PPVs) of CT, EUS and MRI were 70%, 75% and 87%, respectively. Pancreatic MRI appears to be the most appropriate examination to diagnose pPCNs accurately. EUS alone had a poor PPV. Mural nodules in a PCN should not be considered an indisputable sign of pPCN invasiveness. © 2015 International Hepato-Pancreato-Biliary Association.

Indication for and accuracy of CT and MRI of the temporomandibular joint

International Nuclear Information System (INIS)

Greess, H.; Anders, K.

2005-01-01

Recurrent pains of the temporomandibular joint represent a frequent symptom with numerous different causes. CT and MRI can reliably show the cause of these disorders and therefore have substituted conventional X-ray imaging. Modern multi-slice-CT (MSCT) allows for examination of the skull base including the mandible in a very short time with thinnest slice collimation (0.75 mm). With 2D- and 3D- reformations reconstructed out of this volume data set in parasagittal, coronal or any other arbitrary slice orientation excellent imaging of fractures and bony changes of arthrosis as well as benign and malignant tumors of the temporomandibular joint can be performed. MRI offers very good soft tissue contrast in order to visualize the intra-articular disc, the ligaments and muscles, as well the possibility to acquire cross sectional images in any user-defined orientation. MRI is the method of choice to diagnose 'internal derangement', particularly displacement of the intra-articular disc and inflammatory disease of the temporomandibular joint. The present paper will provide diagnostic strategies for the use of MSCT or MRI imaging concerning the different causes of disorders to the temporomandibular joint. (orig.)

CT and MRI findings of cyclosporine-related encephalopathy and hypertensive encephalopathy

International Nuclear Information System (INIS)

Yamamoto, Akira; Hayakawa, Katsumi; Houjyou, Makoto

2002-01-01

We present the MRI and CT findings of one child with cyclosporine-related encephalopathy, and one child with hypertensive encephalopathy following cyclosporine-related encephalopathy. The imaging findings were shown well on T2-weighted and fluid-attenuated inversion recovery (FLAIR) MR images. Cyclosporine-related encephalopathy was distributed predominantly in the posterior white matter. Hypertensive encephalopathy showed similar changes of CT attenuation, but with wider distribution. These two disorders seem to have the same pathogenesis. (orig.)

Consistency of parametric registration in serial MRI studies of brain tumor progression

International Nuclear Information System (INIS)

Mang, Andreas; Buzug, Thorsten M.; Schnabel, Julia A.; Crum, William R.; Modat, Marc; Ourselin, Sebastien; Hawkes, David J.; Camara-Rey, Oscar; Palm, Christoph; Caseiras, Gisele Brasil; Jaeger, H.R.

2008-01-01

The consistency of parametric registration in multi-temporal magnetic resonance (MR) imaging studies was evaluated. Serial MRI scans of adult patients with a brain tumor (glioma) were aligned by parametric registration. The performance of low-order spatial alignment (6/9/12 degrees of freedom) of different 3D serial MR-weighted images is evaluated. A registration protocol for the alignment of all images to one reference coordinate system at baseline is presented. Registration results were evaluated for both, multimodal intra-timepoint and mono-modal multi-temporal registration. The latter case might present a challenge to automatic intensity-based registration algorithms due to ill-defined correspondences. The performance of our algorithm was assessed by testing the inverse registration consistency. Four different similarity measures were evaluated to assess consistency. Careful visual inspection suggests that images are well aligned, but their consistency may be imperfect. Sub-voxel inconsistency within the brain was found for allsimilarity measures used for parametric multi-temporal registration. T1-weighted images were most reliable for establishing spatial correspondence between different timepoints. The parametric registration algorithm is feasible for use in this application. The sub-voxel resolution mean displacement error of registration transformations demonstrates that the algorithm converges to an almost identical solution for forward and reverse registration. (orig.)

Perivascular epithelioid cell tumour: Dynamic CT, MRI and clinicopathological characteristics—Analysis of 32 cases and review of the literature

International Nuclear Information System (INIS)

Tan, Y.; Zhang, H.; Xiao, E.-H.

2013-01-01

Aim: To evaluate the dynamic computed tomography (CT), magnetic resonance imaging (MRI), and clinicopathological characteristics of perivascular epithelioid cell tumours (PEComas), thus improving the diagnosis of the tumour. Materials and methods: A retrospective analysis was undertaken of the dynamic CT, MRI, and clinicopathological characteristics of 32 PEComas diagnosed at histopathology during the period 1 January 2005 to 1 March 2012 at two hospitals. Results: The age of the patients ranged from 14–80 years (mean 43.3 years). There were more women in this group (19/32). Solitary tumours were identified in kidney (n = 16), liver (n = 7), gynaecological organs (n = 2), retroperitoneal soft tissue (n = 2), lung (n = 2), palate (n = 1), left groin (n = 1). One patient had multiple tumours in the liver, kidney, and retroperitoneal soft tissue. Dynamic CT (32 cases) and MRI (15 cases) demonstrated tumours that were of low density or hypointense on T1-weighted imaging (WI) and hyperintense on T2WI; some were isodense with fat (CT: 10/32; MRI: 6/15). The tumours usually had well-defined borders and were of a regular shape (CT: 26/32; MRI: 12/15). Tumour diameters ranged from 1.5–18 cm (mean 5.1 cm). Most tumours (CT: 21/32, MRI: 10/15) enhanced heterogeneously and significantly on arterial and venous phases. Tumours appeared slightly hypodense on delayed CT imaging, although some (6/32) had delayed enhancement. The expression rate of HMB-45 (human melanoma black monoclonal antibody) was 100% (32/32). Histological classification in 22 cases (22/32) was epithelioid angiomyolipoma (AML), three (3/32) were clear cell “sugar” tumours (CCSTs), two (2/32) were lymphangioleiomyomatosis (LAM), and two (2/32) were clear cell myomelanocytic tumours of the falciform ligament/ligamentum teres (CCMMT). Three tumours did not have a specific classification. Conclusion: Knowledge of dynamic CT, MRI, and clinicopathological characteristics could help improve the diagnosis of

Role of New Functional MRI Techniques in the Diagnosis, Staging, and Followup of Gynecological Cancer: Comparison with PET-CT

Directory of Open Access Journals (Sweden)

Elena Alvarez Moreno

2012-01-01

Full Text Available Recent developments in diagnostic imaging techniques have magnified the role and potential of both MRI and PET-CT in female pelvic imaging. This article reviews the techniques and clinical applications of new functional MRI (fMRI including diffusion-weighted MRI (DWI, dynamic contrast-enhanced (DCE-MRI, comparing with PET-CT. These new emerging provide not only anatomic but also functional imaging, allowing detection of small volumes of active tumor at diagnosis and early disease relapse, which may not result in detectable morphological changes at conventional imaging. This information is useful in distinguishing between recurrent/residual tumor and post-treatment changes and assessing treatment response, with a clear impact on patient management. Both PET-CT and now fMRI have proved to be very valuable tools for evaluation of gynecologic tumors. Most papers try to compare these techniques, but in our experience both are complementary in management of these patients. Meanwhile PET-CT is superior in diagnosis of ganglionar disease; fMRI presents higher accuracy in local preoperative staging. Both techniques can be used as biomarkers of tumor response and present high accuracy in diagnosis of local recurrence and peritoneal dissemination, with complementary roles depending on histological type, anatomic location and tumoral volume.

Diagnostic role of (99)Tc(m)-MDP SPECT/CT combined SPECT/MRI Multi modality imaging for early and atypical bone metastases.

Science.gov (United States)

Chen, Xiao-Liang; Li, Qian; Cao, Lin; Jiang, Shi-Xi

2014-01-01

The bone metastasis appeared early before the bone imaging for most of the above patients. (99)Tc(m)-MDP ((99)Tc(m) marked methylene diphosphonate) bone imaging could diagnosis the bone metastasis with highly sensitivity, but with lower specificity. The aim of this study is to explore the diagnostic value of (99)Tc(m)-MDP SPECT/CT combined SPECT/MRI Multi modality imaging for the early period atypical bone metastases. 15 to 30 mCi (99)Tc(m)-MDP was intravenously injected to the 34 malignant patients diagnosed as doubtful early bone metastases. SPECT, CT and SPECT/CT images were captured and analyzed consequently. For the patients diagnosed as early period atypical bone metastases by SPECT/CT, combining the SPECT/CT and MRI together as the SPECT/MRI integrated image. The obtained SPECT/MRI image was analyzed and compared with the pathogenic results of patients. The results indicated that 34 early period doubtful metastatic focus, including 34 SPECT positive focus, 17 focus without special changes by using CT method, 11 bone metastases focus by using SPECT/CT method, 23 doubtful bone metastases focus, 8 doubtful bone metastases focus, 14 doubtful bone metastases focus and 2 focus without clear image. Totally, SPECT/CT combined with SPECT/MRI method diagnosed 30 bone metastatic focus and 4 doubtfully metastatic focus. In conclusion, (99)Tc(m)-MDP SPECT/CT combined SPECT/MRI Multi modality imaging shows a higher diagnostic value for the early period bone metastases, which also enhances the diagnostic accuracy rate.

A clinical study on the usefulness of CT and MRI imaging in evaluating differential diagnosis and the degree of dementia in vascular dementia

Energy Technology Data Exchange (ETDEWEB)

Hagiwara, Mariko [Nippon Medical School, Tokyo (Japan)

1990-06-01

In a retrospective review of 117 computed tomography (CT) scans and 56 magnetic resonance imaging (MRI) scans sequentially performed for dementia patients, CT and MRI were compared for assessment of the usefulness in the differential diagnosis and determination of the functional prognosis of vascular dementia. The correlation between CT findings and the degree of mental function was also examined. Since MRI had a higher sensitivity than CT in detecting small infarcts or lacunaes in the perforating area or white matter, it should differentiate vascular dementia from dementia of Alzheimer type. When both dementia of Alzheimer type was clinically diagnosed and infarct areas were detected on either CT or MRI, activity of daily living tended to be poor. Even when mixed type of dementia or vascular dementia was clinically diagnosed in spite of negative findings on either CT or MRI, troublesome behavior was frequently observed, posing the likelihood of dementia of Alzheimer type. The ability of CT and MRI to detect lesions was not correlated with the degree of dementia or aging, even if MRI was capable of detecting smaller lesions. CT was thus considered to be more specific modality for evaluating mental function. The size of lesions on CT was found to be more significant than the number and localization of lesions in determining the degree of dementia in the chronic stage of cerebrovascular disease. The ability of MRI to detect smaller lesions, as well as clinically determined ischemic scores, may assist in the diagnostic differentiation. Lesion size on CT may be an important factor for determining the degree of dementia and functional prognosis. (N.K.).

A clinical study on the usefulness of CT and MRI imaging in evaluating differential diagnosis and the degree of dementia in vascular dementia

International Nuclear Information System (INIS)

Hagiwara, Mariko

1990-01-01

In a retrospective review of 117 computed tomography (CT) scans and 56 magnetic resonance imaging (MRI) scans sequentially performed for dementia patients, CT and MRI were compared for assessment of the usefulness in the differential diagnosis and determination of the functional prognosis of vascular dementia. The correlation between CT findings and the degree of mental function was also examined. Since MRI had a higher sensitivity than CT in detecting small infarcts or lacunaes in the perforating area or white matter, it should differentiate vascular dementia from dementia of Alzheimer type. When both dementia of Alzheimer type was clinically diagnosed and infarct areas were detected on either CT or MRI, activity of daily living tended to be poor. Even when mixed type of dementia or vascular dementia was clinically diagnosed in spite of negative findings on either CT or MRI, troublesome behavior was frequently observed, posing the likelihood of dementia of Alzheimer type. The ability of CT and MRI to detect lesions was not correlated with the degree of dementia or aging, even if MRI was capable of detecting smaller lesions. CT was thus considered to be more specific modality for evaluating mental function. The size of lesions on CT was found to be more significant than the number and localization of lesions in determining the degree of dementia in the chronic stage of cerebrovascular disease. The ability of MRI to detect smaller lesions, as well as clinically determined ischemic scores, may assist in the diagnostic differentiation. Lesion size on CT may be an important factor for determining the degree of dementia and functional prognosis. (N.K.)

Correlating tumor metabolic progression index measured by serial FDG PET-CT, apparent diffusion coefficient measured by magnetic resonance imaging (MRI) and blood genomics to patient’s outcome in advanced colorectal cancer: the CORIOLAN study

International Nuclear Information System (INIS)

Deleporte, Amelie; Charette, Nicolas; Machiels, Godelieve; Piccart, Martine; Flamen, Patrick; Hendlisz, Alain; Paesmans, Marianne; Garcia, Camilo; Vandeputte, Caroline; Lemort, Marc; Engelholm, Jean-Luc; Hoerner, Frederic; Aftimos, Philippe; Awada, Ahmad

2014-01-01

Metastatic colorectal cancer (mCRC) may present various behaviours that define different courses of tumor evolution. There is presently no available tool designed to assess tumor aggressiveness, despite the fact that this is considered to have a major impact on patient outcome. CORIOLAN is a single-arm prospective interventional non-therapeutic study aiming mainly to assess the natural tumor metabolic progression index (TMPI) measured by serial FDG PET-CT without any intercurrent antitumor therapy as a prognostic factor for overall survival (OS) in patients with mCRC. Secondary objectives of the study aim to test the TMPI as a prognostic marker for progression-free survival (PFS), to assess the prognostic value of baseline tumor FDG uptake on PFS and OS, to compare TMPI to classical clinico-biological assessment of prognosis, and to test the prognostic value on OS and PFS of MRI-based apparent diffusion coefficient (ADC) and variation of vADC using voxel-based diffusion maps. Additionally, this study intends to identify genomic and epigenetic factors that correlate with progression of tumors and the OS of patients with mCRC. Consequently, this analysis will provide information about the signaling pathways that determine the natural and therapy-free course of the disease. Finally, it would be of great interest to investigate whether in a population of patients with mCRC, for which at present no known effective therapy is available, tumor aggressiveness is related to elevated levels of circulating tumor cells (CTCs) and to patient outcome. Tumor aggressiveness is one of the major determinants of patient outcome in advanced disease. Despite its importance, supported by findings reported in the literature of extreme outcomes for patients with mCRC treated with chemotherapy, no objective tool allows clinicians to base treatment decisions on this factor. The CORIOLAN study will characterize TMPI using FDG-PET-based metabolic imaging of patients with chemorefractory m

CT and MRI findings of cerebral ischemic lesions in the cortical and perforating arterial system

Energy Technology Data Exchange (ETDEWEB)

Kameyama, Masakuni; Udaka, Fukashi; Nishinaka, Kazuto; Kodama, Mitsuo; Urushidani, Makoto; Kawamura, Kazuyuki; Inoue, Haruhisa; Kageyama, Taku [Sumitomo Hospital, Osaka (Japan)

1995-07-01

It is clinically useful to divide the location of infarction into the cortical and perforating arterial system. Computerized tomography (CT) and magnetic resonance imaging (MRI) now make the point of infarction a simple and useful task in daily practice. The diagnostic modality has also demonstrated that risk factors and clinical manifestations are different for infarction in the cortical as opposed to the perforating system. In this paper, we present various aspects of images of cerebral ischemia according to CT and/or MRI findings. With the advance of imaging mechanics, diagnostic capability of CT or/and MRI for cerebral infarction has markedly been improved. We must consider these points on evaluating the previously reported results. In addition, we always consider the pathological background of these image-findings for the precise interpretation of their clinical significance. In some instances, dynamic study such as PET or SPECT is needed for real interpretations of CT and/or MRI images. We paid special reference to lacunar stroke and striatocapsular infarct. In addition, `branch atheromatous disease (Caplan)` was considered, in particular, for their specific clinical significances. Large striatocapsular infarcts frequently show cortical signs and symptoms such as aphasia or agnosia in spite of their subcortical localization. These facts, although have previously been known, should be re-considered for their pathoanatomical mechanism. (author).

CT and MRI findings of cerebral ischemic lesions in the cortical and perforating arterial system

International Nuclear Information System (INIS)

Kameyama, Masakuni; Udaka, Fukashi; Nishinaka, Kazuto; Kodama, Mitsuo; Urushidani, Makoto; Kawamura, Kazuyuki; Inoue, Haruhisa; Kageyama, Taku

1995-01-01

It is clinically useful to divide the location of infarction into the cortical and perforating arterial system. Computerized tomography (CT) and magnetic resonance imaging (MRI) now make the point of infarction a simple and useful task in daily practice. The diagnostic modality has also demonstrated that risk factors and clinical manifestations are different for infarction in the cortical as opposed to the perforating system. In this paper, we present various aspects of images of cerebral ischemia according to CT and/or MRI findings. With the advance of imaging mechanics, diagnostic capability of CT or/and MRI for cerebral infarction has markedly been improved. We must consider these points on evaluating the previously reported results. In addition, we always consider the pathological background of these image-findings for the precise interpretation of their clinical significance. In some instances, dynamic study such as PET or SPECT is needed for real interpretations of CT and/or MRI images. We paid special reference to lacunar stroke and striatocapsular infarct. In addition, 'branch atheromatous disease (Caplan)' was considered, in particular, for their specific clinical significances. Large striatocapsular infarcts frequently show cortical signs and symptoms such as aphasia or agnosia in spite of their subcortical localization. These facts, although have previously been known, should be re-considered for their pathoanatomical mechanism. (author)