Magnetic resonance findings in amyotrophic lateral sclerosis using a spin echo magnetization transfer sequence: preliminary report

Directory of Open Access Journals (Sweden)

ROCHA ANTÔNIO JOSÉ DA

1999-01-01

Full Text Available We present the magnetic resonance (MR findings of five patients with amyotrophic lateral sclerosis (ALS using a spin-echo sequence with an additional magnetization transfer (MT pulse on T1-weighted images (T1 SE/MT. These findings were absent in the control group and consisted of hyperintensity of the corticospinal tract. Moreover we discuss the principles and the use of this fast but simple MR technique in the diagnosis of ALS

Lymphoma of uterine cervix: magnetic resonance imaging findings

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Kanaan, Daniel; Constantino, Carolina Pesce Lamas; Souza, Rodrigo Canellas de, E-mail: daniel.kanaan@hotmail.com [Department of Radiology, Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil); Parente, Daniella Braz [Instituto D' Or de Pesquisa e Ensino, Rio de Janeiro, RJ (Brazil)

2012-05-15

Lymphoma of the cervix is a rare disease. About 1.0% to 1.5% of extranodal lymphomas originates in the female genital tract. The clinical presentation of this condition is nonspecific and magnetic resonance imaging is important for diagnostic elucidation. The present report describes the case of a 80-year-old patient with lumbar pain, whose magnetic resonance imaging showed a large uterine mass. The final diagnosis was lymphoma. (author)

Pyogenic and tuberculous discitis: magnetic resonance imaging findings for differential diagnosis

Directory of Open Access Journals (Sweden)

Cristiano Gonzaga de Souza

2013-06-01

Full Text Available Spondylodiscitis represents 2%–4% of all bone infections cases. The correct diagnosis and appropriate treatment can prevent complications such as vertebral collapse and spinal cord compression, avoiding surgical procedures. The diagnosis is based on characteristic clinical and radiographic findings and confirmed by blood culture and biopsy of the disc or the vertebra. The present study was developed with Clementino Fraga Filho University Hospital patients with histopathologically and microbiologically confirmed diagnosis of spondylodiscitis, submitted to magnetic resonance imaging of the affected regions. In most cases, pyogenic spondylodiscitis affects the lumbar spine. The following findings are suggestive of the diagnosis: segmental involvement; ill-defined abscesses; early intervertebral disc involvement; homogeneous vertebral bodies and intervertebral discs involvement. Tuberculous spondylodiscitis affects preferentially the thoracic spine. Most suggestive signs include: presence of well-defined and thin-walled abscess; multisegmental, subligamentous involvement; heterogeneous involvement of vertebral bodies; and relative sparing of intervertebral discs. The present pictorial essay is aimed at showing the main magnetic resonance imaging findings of pyogenic and tuberculous discitis.

Chronic hepatosplenic schistosomiasis mansoni: magnetic resonance imaging and magnetic resonance angiography findings

International Nuclear Information System (INIS)

Bezerra, A.S.; D'Ippolito, G.; Caldana, R.P.; Cecin, A.O.; Ahmed, M.; Szejnfeld, J.

2007-01-01

Purpose: To evaluate the hepatosplenic manifestations and the portal venous system in patients with chronic infection by Schistosoma mansoni. Material and Methods: A cross-sectional observational study was performed in 28 patients with chronic hepatosplenic schistosomiasis submitted to magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) of the abdomen. Images were interpreted independently by two radiologists to determine the reproducibility of image interpretation and who evaluated the presence of morphological alterations in the liver and spleen, such as hepatosplenomegaly, hepatic fissure widening, periportal fibrosis, and the presence of siderotic nodules. Interobserver and intra-observer agreement were measured with the kappa and intraclass correlation tests. Evaluation of venous collateral pathways and portal and splenic veins was done in consensus by both examiners. Results: Observers identified enlargement of the left lobe (78.5-92.8%) and caudate-to-right-lobe ratio (78.5-92.8%), irregularity of hepatic contours (89.2-96.4%), fissure widening (89.2-100%), and splenic siderotic nodules (84.2%). Splenomegaly, heterogeneity of hepatic parenchyma, peripheral hepatic vessels, and periportal fibrosis were observed in 100% of patients. MRI findings presented almost perfect interobserver (kappa 0.65-1) and intra-observer (kappa = 0.73-1 for observer 1, and kappa = 0.65-1 for observer 2) agreement for the variables analyzed. MRA showed the presence of collateral pathways in the majority of patients (71.4%) along with widening of portal and splenic veins. Conclusion: Using MRI, hepatosplenic alterations in schistosomiasis are characterized by heterogeneity of hepatic parenchyma, presence of peripheral perihepatic vessels, periportal fibrosis, splenomegaly, siderotic nodules, and the presence of venous collateral pathways

Magnetic resonance imaging findings of cellular angiofibroma of the tunica vaginalis of the testis: a case report.

Science.gov (United States)

Ntorkou, Alexandra A; Tsili, Athina C; Giannakis, Dimitrios; Batistatou, Anna; Stavrou, Sotirios; Sofikitis, Nikolaos; Argyropoulou, Maria I

2016-03-31

Cellular angiofibroma represents a rare mesenchymal tumor typically involving the inguinoscrotal area in middle-aged men. Although the origin of this benign tumor is unknown, it is histologically classified as an angiomyxoid tumor. Cellular angiofibroma is characterized by a diversity of pathological and imaging features. An accurate preoperative diagnosis is challenging. Magnetic resonance imaging examination of the scrotum has been reported as a valuable adjunct modality in the investigation of scrotal pathology. The technique by providing both structural and functional information is useful in the differentiation between extratesticular and intratesticular diseases and in the preoperative characterization of the histologic nature of various scrotal lesions. There are few reports in the English literature addressing the magnetic resonance imaging findings of cellular angiofibroma of the scrotum and no reports on functional magnetic resonance imaging data. Here we present the first case of a cellular angiofibroma arising from the tunica vaginalis of the testis and we discuss the value of a multiparametric magnetic resonance protocol, including diffusion-weighted imaging, magnetization transfer imaging and dynamic contrast-enhanced magnetic resonance imaging in the preoperative diagnosis of this rare neoplasm. A 47-year Greek man presented with a painless left scrotal swelling, which had gradually enlarged during the last 6 months. Magnetic resonance imaging of his scrotum displayed a left paratesticular mass, in close proximity to the tunica vaginalis, with heterogeneous high signal intensity on T2-weighted images and no areas of restricted diffusion. The tumor was hypointense on magnetization transfer images, suggestive for the presence of macromolecules. On dynamic contrast-enhanced magnetic resonance imaging the mass showed intense heterogeneous enhancement with a type II curve. Magnetic resonance imaging findings were strongly suggestive of a benign

Magnetic Resonance Imaging Findings of Adult-Onset Glutaric Aciduria Type

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Sonmez, G.; Mutlu, H.; Ozturk, E.; Sildiroglu, H.O.; Keskin, A.T.; Basekim, C.C.; Kizilkaya, E. [Dept. of Radiology, GATA Haydarpasa Teaching Hospital, Istanbul (Turkey)

2007-07-15

Glutaric aciduria or glutaric acidemia type I, an autosomal recessive disease, usually presents with an acute encephalopathic crisis in young children. We report the magnetic resonance (MR) and proton MR spectroscopy (MRS) imaging findings of a previously healthy 20-year-old man who presented with recurrent headaches. Organic acids from the patient's urine contained large amounts of adipate, glutarate, and 3-hydroxyglutarate consistent with glutaric aciduria type I.

Magnetic Resonance Imaging Findings of Adult-Onset Glutaric Aciduria Type

International Nuclear Information System (INIS)

Sonmez, G.; Mutlu, H.; Ozturk, E.; Sildiroglu, H.O.; Keskin, A.T.; Basekim, C.C.; Kizilkaya, E.

2007-01-01

Glutaric aciduria or glutaric acidemia type I, an autosomal recessive disease, usually presents with an acute encephalopathic crisis in young children. We report the magnetic resonance (MR) and proton MR spectroscopy (MRS) imaging findings of a previously healthy 20-year-old man who presented with recurrent headaches. Organic acids from the patient's urine contained large amounts of adipate, glutarate, and 3-hydroxyglutarate consistent with glutaric aciduria type I

Magnetic resonance imaging findings in a red kangaroo (Macropus rufus) with otitis.

Science.gov (United States)

Okeson, Danelle M; Coke, Rob L; Kochunov, Peter; Davis, M Duff

2008-12-01

Magnetic resonance imaging (MRI) was performed on an adult, male Red kangaroo (Macropus rufus) with a history of nonspecific neurologic signs and acute discharge from the left ear. MRI revealed findings consistent with otitis and possible osteomyelitis of the temporal and mastoid bones. To the authors' knowledge, this is the first report of otitis and MRI findings in a kangaroo.

Correlation of computed tomographic and magnetic resonance imaging findings in cerebral infartion

International Nuclear Information System (INIS)

Komatsubara, Chizuko; Chuda, Moriyoshi; Taka, Toshihiko

1989-01-01

We evaluated neurological findings in 75 patients of cerebral infarction, and correlated computed tomographic (CT) and magnetic resonance imaging (MRI) findings. MRI was found to have the advantage when the lesion were multiple, or in the posterior fossa. MRI demonstrates the anatomical details, and lacks the bony artifact, so it is an excellent method for identification of cerebral infarction. (author)

Parenchymal abnormalities in cerebral venous thrombosis: findings of magnetic resonance imaging and magnetic resonance angiography

International Nuclear Information System (INIS)

Ferreira, Clecia Santos; Pellini, Marcos; Boasquevisque, Edson; Souza, Luis Alberto M. de

2006-01-01

Objective: to determine the frequency and localization of parenchymal abnormalities in cerebral venous thrombosis on magnetic resonance imaging and magnetic resonance angiography as well as their correlation with the territory and affected venous drainage. Materials and methods: retrospective analysis (1996 to 2004) of 21 patients (3 male and 18 female) age range between 3 and 82 years (mean 40 years, median 36 years) with clinical and radiological diagnosis of cerebral venous thrombosis on magnetic resonance imaging and magnetic resonance angiography in 2D PC, 3D PC and contrast-enhanced 3D TOF sequences. The statistical analysis was performed with the qui-square test. Four patients had follow-up exams and three patients underwent digital subtraction angiography. Results: main predisposing factors were: infection, use of oral contraceptives, hormone replacement therapy and collagenosis. Predominant symptoms included: focal deficit, headache, alteration of consciousness level and seizures. Most frequent parenchymal manifestations were: cortical/subcortical edema or infarct, venous congestion and collateral circulation, meningeal enhancement and thalamic and basal ganglia edema or infarct. Occlusion occurred mainly in superior sagittal, left transverse, left sigmoid and straight sinuses. Cavernous sinus and cortical veins thrombosis are uncommon events. Conclusion: cerebral venous thrombosis is an uncommon cause of stroke, with favorable prognosis because of its reversibility. Diagnosis is highly dependent on the radiologist capacity to recognize the presentations of this disease, principally in cases where the diagnosis is suggested by parenchymal abnormalities rather than necessarily by visualization of the thrombus itself. An accurate and rapid diagnosis allows an immediate treatment, reducing the morbidity and mortality rates. (author)

Hallervorden Spatz syndrome: magnetic resonance findings. Case report

International Nuclear Information System (INIS)

Farage, Luciano; Castro, Mario Augusto Padula; Macedo, Tulio Augusto Alves; Assis, Marcelo Cardoso de; Souza, Lincoln Pereira de; Freitas, Luiz Oliveira de

2004-01-01

Hallervorden-Spatz syndrome is a neuro degenerative disease, autosomic recessive with two clinical features: early and late onset. Psychiatric, pyramidal and extrapyramidal signs are present in the late subtype. We report the case of a 41-old woman with extrapyramidal signs. Magnetic resonance imaging (MRI) showed the eye-of-the-tiger sign in the medial globus pallidus. This is due to a gliosis (increased signal) and accumulation of surrounding iron (decreased signal intensity) in long T R sequences. There is a strong relationship between MRI findings and the gene mutation responsible for this disease. It makes the MRI sensible for diagnosing this syndrome. (author)

Magnetic resonance imaging findings in tuberculous meningoencephalitis

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Pui, M.H.; Memon, W.A. [Aga Khan Univ. Hospital, Dept. of Radiology, Karachi (Pakistan)

2001-02-01

To evaluate the efficacy of magnetic resonance imaging (MRI) for distinguishing tuberculosis from other types of meningoencephalitis. MRIs of 100 patients with tuberculous (50), pyogenic (33), viral (14), or fungal (3) meningoencephalitis were analyzed independently by 2 radiologists. Number, size, location, signal characteristics, surrounding edema, and contrast enhancement pattern of nodular lesions; location and pattern of meningeal enhancement; extent of infarct or encephalitis and hydrocephalus were evaluated. Contrast-enhancing nodular lesions were detected in patients with tuberculous (43 of 50 patients), pyogenic (9 of 33), and fungal (3 of 3) infections. No nodules were detected in patients with viral meningoencephalitis. Using the criteria of 1 or more solid rim or homogeneously enhancing nodules smaller than 2 cm, the sensitivity, specificity and accuracy for diagnosing tuberculous meningitis were 86.0%, 90.0% and 88.0%, respectively. Magnetic resonance imaging is useful in distinguishing tuberculous from pyogenic, viral and fungal meningoencephalitis. (author)

Brachialis periosteal avulsion injury: case report with magnetic resonance imaging findings

International Nuclear Information System (INIS)

Lam, Justin Chak Yiu; Lee, Ka Lok Ryan; Griffith, James F.

2016-01-01

Brachialis periosteal avulsion injury is an uncommon injury occurring in young children. The injury may be misinterpreted or overlooked because of misleading or subtle radiological findings. A case of 7-year-old child with post-traumatic elbow pain and subtle findings on elbow radiography is presented. The injury was initially misinterpreted as an avulsion fracture of the medial epicondyle. Following radiological review, a diagnosis of brachialis periosteal avulsion injury was made. The radiographic and magnetic resonance imaging (MRI) findings of this injury are presented to stress the value of comparing the radiographic findings with previous imaging and to increase awareness of this uncommon injury. (orig.)

Brachialis periosteal avulsion injury: case report with magnetic resonance imaging findings

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Lam, Justin Chak Yiu; Lee, Ka Lok Ryan; Griffith, James F. [Prince of Wales Hospital, Department of Imaging and Interventional Radiology, Shatin, N.T (China)

2016-11-15

Brachialis periosteal avulsion injury is an uncommon injury occurring in young children. The injury may be misinterpreted or overlooked because of misleading or subtle radiological findings. A case of 7-year-old child with post-traumatic elbow pain and subtle findings on elbow radiography is presented. The injury was initially misinterpreted as an avulsion fracture of the medial epicondyle. Following radiological review, a diagnosis of brachialis periosteal avulsion injury was made. The radiographic and magnetic resonance imaging (MRI) findings of this injury are presented to stress the value of comparing the radiographic findings with previous imaging and to increase awareness of this uncommon injury. (orig.)

HLA typing in acute optic neuritis. Relation to multiple sclerosis and magnetic resonance imaging findings

DEFF Research Database (Denmark)

Frederiksen, J.L.; Madsen, H.O.; Ryder, L.P.

1997-01-01

OBJECTIVE: To study the association of brain magnetic resonance imaging (MRI) findings and HLA findings to clarify the relationship between monosymptomatic optic neuritis (ON) and ON as part of clinically definite multiple sclerosis (CDMS). DESIGN: Population-based cohort of patients with ON refe......OBJECTIVE: To study the association of brain magnetic resonance imaging (MRI) findings and HLA findings to clarify the relationship between monosymptomatic optic neuritis (ON) and ON as part of clinically definite multiple sclerosis (CDMS). DESIGN: Population-based cohort of patients......: The frequency of HLA-DR15 was significantly increased in patients with ON + CDMS (52%) and ON (47%) compared with control subjects (31%). The frequency of HLA-DR17 was almost equal in the ON + CDMS (18%), ON (23%), and control (23%) groups. The frequencies of HLA-DQA-1B (55% in ON + CDMS, 58% in ON) and HLA...

Neuroimaging of HIV-associated cryptococcal meningitis: comparison of magnetic resonance imaging findings in patients with and without immune reconstitution.

Science.gov (United States)

Katchanov, Juri; Branding, Gordian; Jefferys, Laura; Arastéh, Keikawus; Stocker, Hartmut; Siebert, Eberhard

2016-02-01

To determine the frequency, imaging characteristics, neuroanatomical distribution and dynamics of magnetic resonance imaging findings in HIV-associated cryptococcal meningitis in immunocompromised patients we compared patients without antiretroviral therapy with patients undergoing immune reconstitution. Neuroimaging and clinical data of 21 consecutive patients presenting to a German HIV centre in a 10-year period between 2005 and 2014 were reviewed. We identified eight patients with magnetic resonance imaging findings related to cryptococcal disease: five patients without antiretroviral therapy and three patients receiving effective antiretroviral therapy resulting in immune reconstitution. The pattern of magnetic resonance imaging manifestations was different in the two groups. In patients not on antiretroviral therapy, pseudocysts (n = 3) and lacunar ischaemic lesions (n = 2) were detected. Contrast-enhancing focal leptomeningeal and/or parenchymal lesions were found in all patients under immune reconstitution (n = 3). Magnetic resonance imaging lesions suggestive of leptomeningitis or meningoencephalitis were detected in all patients with a recurrence of cryptococcal meningitis under immune reconstitution, which differs from the classical magnetic resonance imaging findings in patients without antiretroviral therapy. In antiretroviral therapy-treated patients with past medical history of cryptococcal meningitis, detection of contrast-enhancing focal meningeal and/or parenchymal lesions should prompt further investigations for a recurrence of cryptococcal meningitis under immune reconstitution. © The Author(s) 2015.

Magnetic Resonance Imaging Findings of Adult-Onset Glutaric Aciduria Type I

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Sonmez, G.; Mutlu, H.; Ozturk, E.; Sildiroglu, H.O.; Keskin, A.T.; Basekim, C.C.; Kizilkaya, E. [Dept. of Radiology, GATA Haydarpasa Teaching Hospital, Istanbul (Turkey)

2007-07-15

Glutaric aciduria or glutaric acidemia type I, an autosomal recessive disease, usually presents with an acute encephalopathic crisis in young children. We report the magnetic resonance (MR) and proton MR spectroscopy (MRS) imaging findings of a previously healthy 20-year-old man who presented with recurrent headaches. Organic acids from the patient's urine contained large amounts of adipate, glutarate, and 3-hydroxyglutarate consistent with glutaric aciduria type I.

Magnetic Resonance Sensors

Directory of Open Access Journals (Sweden)

Robert H. Morris

2014-11-01

Full Text Available Magnetic Resonance finds countless applications, from spectroscopy to imaging, routinely in almost all research and medical institutions across the globe. It is also becoming more frequently used for specific applications in which the whole instrument and system is designed for a dedicated application. With beginnings in borehole logging for the petro-chemical industry Magnetic Resonance sensors have been applied to fields as varied as online process monitoring for food manufacture and medical point of care diagnostics. This great diversity is seeing exciting developments in magnetic resonance sensing technology published in application specific journals where they are often not seen by the wider sensor community. It is clear that there is enormous interest in magnetic resonance sensors which represents a significant growth area. The aim of this special edition of Sensors was to address the wide distribution of relevant articles by providing a forum to disseminate cutting edge research in this field in a single open source publication.[...

Focal Pancreatitis Mimicking Pancreatic Mass: Magnetic Resonance Imaging (MRI)/Magnetic Resonance Cholangiopancreatography (MRCP) Findings Including Diffusion-Weighted MRI

International Nuclear Information System (INIS)

Momtahen, A.J.; Balci, N.C.; Alkaade, S.; Akduman, E.I.; Burton, F.R.

2008-01-01

Background: Focal pancreatitis (FP) is a confined inflammation that mimics a pancreatic mass. Its imaging diagnosis is important to avoid unnecessary procedures. Purpose: To describe the spectrum of magnetic resonance imaging (MRI)/magnetic resonance cholangiopancreatography (MRCP) and diffusion-weighted MRI (DWI) findings of focal pancreatitis mimicking pancreatic masses. Material and Methods: Findings of MRI/MRCP including DWI with a b value of 0 and 600 s/mm2 in 14 patients with pancreatic masses on MRI were retrospectively reviewed and compared to normal pancreas in 14 patients as a control group. Results: FP revealed hypointense signal intensity (SI) (3/14), hypo- to isointense SI (7/14), or isointense SI (4/14) on T1-weighted images, and hypointense SI (1/14), isointense SI (5/14), iso- to hyperintense SI (7/14), or hyperintense SI (1/14) on T2-weighted images compared to remaining pancreas (RP). MRCP images revealed dilatation of the common bile duct (CBD) and main pancreatic duct (MPD) (5/14), dilatation of the MPD only (3/14), dilatation of the CBD only (3/14), and normal MPD and CBD (3/14). Both FP and RP revealed three types of time-signal intensity curves: 1) rapid rise to a peak, with a rapid decline (FP=2, RP=4), 2) slow rise to a peak, followed by a slow decline (FP=5, RP=4), and 3) slower rise to a peak, with a slow decline or plateau (FP=7, RP=6). Mean apparent diffusion coefficient (ADC) values for FP and RP were 2.09±0.18 and 2.03±0.2x10 -3 mm 2 /s, respectively. ADC values of FP and RP revealed no significant difference. Conclusion: The spectrum of imaging findings of focal pancreatitis on MRI/MRCP including DWI was described. Findings of FP were not distinctive as compared to the remaining pancreas

Migraine and magnetic resonance spectroscopy

DEFF Research Database (Denmark)

Younis, Samaira; Hougaard, Anders; Vestergaard, Mark B.

2017-01-01

Purpose of review: To present an updated and streamlined overview of the metabolic and biochemical aspect of the migraine pathophysiology based on findings from phosphorous (31P) and hydrogen (1H) magnetic resonance spectroscopy (MRS) studies. Recent findings: Despite of the variation in the meth......Purpose of review: To present an updated and streamlined overview of the metabolic and biochemical aspect of the migraine pathophysiology based on findings from phosphorous (31P) and hydrogen (1H) magnetic resonance spectroscopy (MRS) studies. Recent findings: Despite of the variation...

Associations between spondyloarthritis features and magnetic resonance imaging findings

DEFF Research Database (Denmark)

Arnbak, Bodil; Jurik, Anne Grethe; Hørslev-Petersen, Kim

2016-01-01

were 1) to estimate the prevalence of magnetic resonance imaging (MRI) findings and clinical features included in the ASAS criteria for SpA and 2) to explore the associations between MRI findings and clinical features. METHODS: We included patients ages 18-40 years with persistent low back pain who had...... been referred to the Spine Centre of Southern Denmark. We collected information on clinical features (including HLA-B27 and high-sensitivity C-reactive protein) and MRI findings in the spine and sacroiliac (SI) joints. RESULTS: Of 1,020 included patients, 537 (53%) had at least 1 of the clinical...... according to the ASAS definition was present in 217 patients (21%). Of those 217 patients, 91 (42%) had the minimum amount of bone marrow edema required according to the ASAS definition (a low bone marrow edema score). The presence of HLA-B27, peripheral arthritis, a good response to NSAIDs, and preceding...

Reliability of clinical findings and magnetic resonance imaging for the diagnosis of chondromalacia patellae.

Science.gov (United States)

Pihlajamäki, Harri K; Kuikka, Paavo-Ilari; Leppänen, Vesa-Veikko; Kiuru, Martti J; Mattila, Ville M

2010-04-01

This diagnostic study was performed to determine the correlation between anterior knee pain and chondromalacia patellae and to define the reliability of magnetic resonance imaging for the diagnosis of chondromalacia patellae. Fifty-six young adults (median age, 19.5 years) with anterior knee pain had magnetic resonance imaging of the knee followed by arthroscopy. The patellar chondral lesions identified by magnetic resonance imaging were compared with the arthroscopic findings. Arthroscopy confirmed the presence of chondromalacia patellae in twenty-five (45%) of the fifty-six knees, a synovial plica in twenty-five knees, a meniscal tear in four knees, and a femorotibial chondral lesion in four knees; normal anatomy was seen in six knees. No association was found between the severity of the chondromalacia patellae seen at arthroscopy and the clinical symptoms of anterior knee pain syndrome (p = 0.83). The positive predictive value for the ability of 1.0-T magnetic resonance imaging to detect chondromalacia patellae was 75% (95% confidence interval, 53% to 89%), the negative predictive value was 72% (95% confidence interval, 56% to 84%), the sensitivity was 60% (95% confidence interval, 41% to 77%), the specificity was 84% (95% confidence interval, 67% to 93%), and the diagnostic accuracy was 73% (95% confidence interval, 60% to 83%). The sensitivity was 13% (95% confidence interval, 2% to 49%) for grade-I lesions and 83% (95% confidence interval, 59% to 94%) for grade-II, III, or IV lesions. Chondromalacia patellae cannot be diagnosed on the basis of symptoms or with current physical examination methods. The present study demonstrated no correlation between the severity of chondromalacia patellae and the clinical symptoms of anterior knee pain syndrome. Thus, symptoms of anterior knee pain syndrome should not be used as an indication for knee arthroscopy. The sensitivity of 1.0-T magnetic resonance imaging was low for grade-I lesions but considerably higher for more

Magnetic resonance imaging findings of disc-related epidural cysts in nonsurgical and postoperative patients

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Simao, Marcelo Novelino, E-mail: marcelo_simao@hotmail.com [Central de Diagnostico Ribeirao Preto (CEDIRP), Ribeirao Preto, SP (Brazil); Helms, Clyde A. [Radiology, Musculoskeletal Section, Duke University Medical Center, Durham, NC (United States); Richardson, William J. [Orthopedic Surgery, Spine Surgery Section, Duke University Medical Center, Durham, NC (United States)

2012-07-15

Objective: To demonstrate five discal cysts with detailed magnetic resonance imaging findings in nonsurgical and following postoperative microdiscectomy. Materials And Methods: Five discal cysts in four patients who underwent magnetic resonance imaging were found through a search in our database and referral from a single orthopedic spine surgeon. Computed tomography in two cases and computed tomography discography in one case were also performed. Results: Five discal cysts were present in four patients. Three patients had no history of previous lumbar surgery and the other patient presented with two discal cysts and recurrent symptoms after partial laminectomy and microdiscectomy. All were oval shaped and seated in the anterior epidural space. Four were ventrolateral, and the other one was centrally positioned in the anterior spinal canal. One showed continuity with the central disc following discography. Three were surgically removed. Conclusion: Magnetic resonance imaging can easily depict an epidural cyst and the diagnosis of a discal cyst should be raised when an homogeneous ventrolateral epidural cyst contiguous to a mild degenerated disc is identified. (author)

Magnetic resonance imaging findings of disc-related epidural cysts in nonsurgical and postoperative patients

International Nuclear Information System (INIS)

Simao, Marcelo Novelino; Helms, Clyde A.; Richardson, William J.

2012-01-01

Objective: To demonstrate five discal cysts with detailed magnetic resonance imaging findings in nonsurgical and following postoperative microdiscectomy. Materials And Methods: Five discal cysts in four patients who underwent magnetic resonance imaging were found through a search in our database and referral from a single orthopedic spine surgeon. Computed tomography in two cases and computed tomography discography in one case were also performed. Results: Five discal cysts were present in four patients. Three patients had no history of previous lumbar surgery and the other patient presented with two discal cysts and recurrent symptoms after partial laminectomy and microdiscectomy. All were oval shaped and seated in the anterior epidural space. Four were ventrolateral, and the other one was centrally positioned in the anterior spinal canal. One showed continuity with the central disc following discography. Three were surgically removed. Conclusion: Magnetic resonance imaging can easily depict an epidural cyst and the diagnosis of a discal cyst should be raised when an homogeneous ventrolateral epidural cyst contiguous to a mild degenerated disc is identified. (author)

Retropharyngeal Tendinitis: Radiographic and Magnetic Resonance Imaging Findings

Energy Technology Data Exchange (ETDEWEB)

Gelineck, J.; Salomonsen, M.; Hviid, C. [Aarhus Univ. Hospital (Denmark). Dept. of Radiology

2006-10-15

Purpose: To describe the magnetic resonance imaging (MRI) findings in retropharyngeal tendinitis. Material and methods: Within 1 year, four patients presenting with symptoms of retropharyngeal tendinitis were examined by radiography and MRI. Results: On MRI and radiographs, all patients had characteristic soft-tissue swellings and calcifications related to the tendon of the longus colli muscle situated inferior to the anterior arc of C1. MRI showed well-defined edema, with high signal in the retropharyngeal tissue anterior to C1-C5 on short T1 inversion recovery (STIR) sequences, low signal on T1-weighted sequences, and low signal in the calcification on both sequences. In addition, three patients had high signal intensity changes on STIR sequences in the atlantoaxial joint situated posterior to the anterior arc of C1. Conclusion: MRI is a sensitive and accurate method in the diagnosis of retropharyngeal tendinitis. A new finding in this condition is an effusion or synovitis in the anterior atlantoaxial joint. MRI is a valuable tool in differentiating retropharyngeal tendinitis from other diagnoses such as retropharyngeal abscess, pyogenic spondylitis, and spondyloarthropathy.

Magnetic resonance annual 1986

International Nuclear Information System (INIS)

Kressel, H.Y.

1986-01-01

This book contains papers written on magnetic resonance during 1986. Topics include: musculosketetal magnetic resonance imaging; imaging of the spine; magnetic resonance chemical shift imaging; magnetic resonance imaging in the central nervous system; comparison to computed tomography; high resolution magnetic resonance imaging using surface coils; magnetic resonance imaging of the chest; magnetic resonance imaging of the breast; magnetic resonance imaging of the liver; magnetic resonance spectroscopy of neoplasms; blood flow effects in magnetic resonance imaging; and current and potential applications of clinical sodium magnetic resonance imaging

Abnormal findings on knee magnetic resonance imaging in asymptomatic NBA players.

Science.gov (United States)

Walczak, Brian E; McCulloch, Patrick C; Kang, Richard W; Zelazny, Anthony; Tedeschi, Fred; Cole, Brian J

2008-01-01

The purpose of this study was to evaluate the knees of asymptomatic National Basketball Association (NBA) players via magnetic resonance imaging (MRI) and confirm or dispute findings reported in the previous literature. It is thought that a variety of significant abnormalities affecting the knee exist in asymptomatic patients and that these findings can be accurately identified on MRI. Two months prior to the 2005 season, bilateral knee MRI examinations of 14 asymptomatic NBA players (28 knees) were evaluated for abnormalities of the articular cartilage, menisci, and patellar and quadriceps tendons. The presence of joint effusion, subchondral edema, and cystic lesions and the integrity of the collateral and cruciate ligaments were also assessed.

Elastofibroma dorsi: computed tomography and magnetic resonance findings in two cases

International Nuclear Information System (INIS)

Cano, A.; Bravo, F.; Garrido, J.; Ortega, R.

2001-01-01

The elastofibroma dorse is a benign, nonencapsulated pseudotumor consisting of a proliferation of fibrous tissue and elastic fibers accompanied by fatty tissue. It is usually locate in the scapular region and can be unilateral or bilateral. The computed tomography and magnetic resonance findings are characteristic and, in the proper clinical context, practically pathognomonic: a fat-containing subcapsular mass with an attenuation coefficient and signal intensity similar to those of the adjacent muscles. We report two new cases of elastofibroma dorsi that fulfilled all the clinical and radiologic criteria, enabling the preoperative diagnosis. (Author) 15 refs

Computed Tomography Perfusion, Magnetic Resonance Imaging, and Histopathological Findings After Laparoscopic Renal Cryoablation: An In Vivo Pig Model

DEFF Research Database (Denmark)

Nielsen, Tommy Kjærgaard; Østraat, Øyvind; Graumann, Ole

2017-01-01

The present study investigates how computed tomography perfusion scans and magnetic resonance imaging correlates with the histopathological alterations in renal tissue after cryoablation. A total of 15 pigs were subjected to laparoscopic-assisted cryoablation on both kidneys. After intervention...... of follow-up, but on microscopic examination, the urothelium was found to be intact in all cases. In conclusion, cryoablation effectively destroyed renal parenchyma, leaving the urothelium intact. Both computed tomography perfusion and magnetic resonance imaging reflect the microscopic findings...

Cerebral Fat Embolism: Diffusion-weighted Magnetic Resonance Imaging Findings

International Nuclear Information System (INIS)

Ryu, C.W.

2005-01-01

PURPOSE: To demonstrate the diffusion-weighted (DWI) magnetic resonance imaging (MRI) findings, and the follow-up MRI findings, of cerebral fat embolism in the acute stage. MATERIAL AND METHODS: The initial DWI and clinical findings of six patients with cerebral fat embolism were retrospectively evaluated. The finding of DWI with a b-value of 1000 s/mm 2 (b=1000) was compared with that of DWI with a b-value of 0 s/mm 2 (b=0). In three patients who underwent follow-up MRI, the interval change of the lesion on T2-weighted images was investigated. RESULTS: The characteristic DWI finding of cerebral fat embolism in the acute stage was multiple, hyperintense, dot-like lesions disseminated in the brain. These lesions were distributed dominantly in the bilateral border-zone areas. Some lesions had an ancillary location including the cortex, deep white matter, basal ganglia, and cerebellum. The lesions were more intense and numerous in DWI (b=1000) than in DWI (b=0). The findings on the follow-up T2-weighted images were multiple confluent hyperintense lesions in the white matter with progression since the initial MRI. CONCLUSION: DWI could be a sensitive tool for detecting cerebral fat embolism in the acute phase. It is recommended that DWI be included in the initial evaluation of cerebral fat embolism with MRI

Magnetic resonance imaging findings in patients with Hallervorden-Spatz syndrome; Achados de ressonancia magnetica na sindrome de Hallervorden-Spatz

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Nomura, Cesar Higa; Lima, Eduardo Carneiro; Cerri, Giovanni Guido; Leite, Claudia da Costa [Sao Paulo Univ., SP (Brazil). Faculdade de Medicina. Dept. de Radiologia; Rosemberg, Sergio [Sao Paulo Univ., SP (Brazil). Faculdade de Medicina. Dept. de Patologia

2003-12-01

The objective of this study was to review the magnetic resonance imaging findings in patients with Hallervorden-Spatz syndrome. We evaluated eight patients with Hallervorden-Spatz syndrome using magnetic resonance imaging. The protocol included at least sagittal and axial T1-weighted images and axial and coronal T2-weighted images. Intravenous gadolinium was administered in a dose of 0.1 mmol/kg. Post-enhanced images were obtained at least in the axial and coronal planes. The results were: all patients presented a bilateral and symmetrical 'tiger-eye signal' on T2-weighted images, corresponding to central hyperintensity and peripheral hypointensity in the globi pallidus. FLAIR and diffusion images showed similar abnormalities. There was no gadolinium enhancement in any of the cases. We concluded that magnetic resonance imaging findings in patients with Hallervorden-Spatz syndrome are very typical and allow the diagnosis of the disease. (author)

Magnetic resonance imaging findings in fatal primary cerebral infection due to Chaetomium strumarium.

Science.gov (United States)

Aribandi, M; Bazan Iii, C; Rinaldi, M G

2005-04-01

This report describes MRI findings of a rare case of biopsy-proven fatal cerebral infection with Chaetomium strumarium in a 28-year-old man with a history of i.v. drug abuse. Magnetic resonance imaging revealed rapidly progressing lesions with irregular peripheral enhancement, possible central haemorrhage and significant mass effect. Only six cases of cerebral infection with Chaetomium have been reported in the English literature. This is the first report in the radiology literature describing the imaging findings. The previously reported cases of cerebral infection by the Chaetomium species are also reviewed.

Left Ventricle Non compaction: Physiopathology and Findings by Magnetic Resonance

International Nuclear Information System (INIS)

Parra R, Rodrigo; Cadavid Lina

2009-01-01

A Left ventricular non compaction (LVNC) has recently been classified as a primary cardiomyopathy with a genetic origin. It is morphologically characterized by numerous prominent trabeculations and deep inter trabecular recesses. LVNC is probably secondary to an arrest in the normal process of myocardial compaction during fetal life. LVNC may be an isolated finding in the absence of any coexisting cardiac anomaly or may be associated with other congenital heart anomalies or neuromuscular disorders. LVNC includes both asymptomatic and symptomatic patients with severe heart failure, systemic embolism, arrhythmia or sudden death. Diagnosis has moved from autopsy to recognition during life by non-invasive means: echocardiography and more recently cardiac magnetic resonance imaging.

Gaucher's disease: Magnetic resonance findings

International Nuclear Information System (INIS)

Roca, M.; Gomez-Pereda, R.; Blasco, A.; Ros, L.

1996-01-01

The objective is to assess the role of magnetic resonance (MR) in determining the initial extension of Gaucher's disease and its complications. A retrospective study of eight patients diagnosed as having Gaucher's disease was carried out using MR. The study focused on pelvis, hip, femur, spine, liver parenchyma and splenic parenchyma. Infiltration of the cancellous portion of the vertebral bodies was observed in all but one of the patients. Three patients presented small hemangiomas in dorsal and lumbar vertebral bodies. Pelvic bone involvement was homogeneous in four cases and spotty in two, while the pelvic marrow was normal in the two patients with no vertebral infiltration. A vascular necrosis of the femoral head was detected in two cases. MR is very useful in determining the initial extension, in the early diagnosis of complications and in managing the posttreatment marrow response to assess the therapeutic efficacy. 16 refs

Specific magnetic resonance imaging findings in patient with progressive supranuciear palsy

International Nuclear Information System (INIS)

Vuchkova, R.; Zlatareva, D.

2013-01-01

Progressive supranuclear palsy (PSP) is a progressive neurodegenerative disease. The clinical symptoms are vertical supranuclear palsy, gait and postural instability, cognitive deficit, Parkinsonism. It is not always possible to differentiate clinically PSP from other atypical Parkinsonian syndromes and from Parkinson disease. We present a case of 56-years old women with clinically suspected PSP. The typical magnetic resonance findings were of most importance in diagnosis. For diagnosing the disease by means of neuroimaging it is necessary to analyze the sagittal MR images what is achievable in daily routine practice without additional software and post processing. (authors)

Hepatocellular adenoma: findings at state-of-the-art magnetic resonance imaging, ultrasound, computed tomography and pathologic analysis

International Nuclear Information System (INIS)

Hussain, Shahid M.; Bos, Indra C. van den; Dwarkasing, Roy S.; Kuiper, Jan-Willem; Hollander, Jan den

2006-01-01

The purpose of this paper is to describe the most recent concepts and pertinent findings of hepatocellular adenomas, including clinical presentation, gross pathology and histology, pathogenesis and transformation into hepatocellular carcinoma (HCC), and imaging findings at ultrasound (US), computed tomography (CT), and magnetic resonance (MR) imaging. (orig.)

Cerebellopontine angle lipomas: magnetic resonance imaging findings in two cases

Energy Technology Data Exchange (ETDEWEB)

Borges, Rafael S. [Clinica de Diagnostico por Imagem Multi-Imagem, Rio de Janeiro, RJ (Brazil); Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Dept. de Radiologia; Brito, Cecilia Castelo Branco [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Fac. de Medicina; Carvalho, Gustavo A. [Clinica Bambina, Rio de Janeiro, RJ (Brazil). Dept. de Neurocirurgia; Hospital Silvestre, Rio de Janeiro, RJ (Brazil); Domingues, Romeu C. [Clinicas CDPI e Multi-Imagem, Rio de Janeiro RJ (Brazil); Gasparetto, Emerson L. [Clinicas CDPI e Multi-Imagem, Rio de Janeiro RJ (Brazil)

2009-07-01

Vestibular schwannomas and meningiomas are the most common lesions of the cerebellopontine angle (CPA), accounting for approximately 85-90% of the tumors seen in this location. Lipomas are rare at this topography, representing about 0.15% of the CPA lesions. These tumors are mal developmental masses that arise from abnormal differentiation of the meninx primitive. Clinically, CPA lipomas can cause slowly progressive neurological symptoms and signs affecting cranial nerves or brain stem. Because these lesions usually are strongly attached to the surrounding structures, any surgical attempts of complete resection can result in neural or vascular damage, reinforcing the importance of the pre-operative imaging diagnosis. Although the CT findings of CPA lipomas can be typical, the magnetic resonance (MR) imaging, especially the fat suppression sequences, had improved the identification of these lesions. We aimed to report two patients with a CPA lipoma, emphasizing the MR imaging findings. (author)

Cerebellopontine angle lipomas: magnetic resonance imaging findings in two cases

International Nuclear Information System (INIS)

Borges, Rafael S.; Domingues, Romeu C.; Gasparetto, Emerson L.

2009-01-01

Vestibular schwannomas and meningiomas are the most common lesions of the cerebellopontine angle (CPA), accounting for approximately 85-90% of the tumors seen in this location. Lipomas are rare at this topography, representing about 0.15% of the CPA lesions. These tumors are mal developmental masses that arise from abnormal differentiation of the meninx primitive. Clinically, CPA lipomas can cause slowly progressive neurological symptoms and signs affecting cranial nerves or brain stem. Because these lesions usually are strongly attached to the surrounding structures, any surgical attempts of complete resection can result in neural or vascular damage, reinforcing the importance of the pre-operative imaging diagnosis. Although the CT findings of CPA lipomas can be typical, the magnetic resonance (MR) imaging, especially the fat suppression sequences, had improved the identification of these lesions. We aimed to report two patients with a CPA lipoma, emphasizing the MR imaging findings. (author)

Complications after liver transplantation: evaluation with magnetic resonance imaging, magnetic resonance cholangiography, and 3-dimensional contrast-enhanced magnetic resonance angiography in a single session

International Nuclear Information System (INIS)

Boraschi, P.; Donati, F.; Gigoni, R.; Salemi, S.; Urbani, L.; Filipponi, F.; Falaschi, F.; Bartolozzi, C.

2008-01-01

To evaluate a comprehensive magnetic resonance imaging (MRI) protocol as noninvasive diagnostic modality for simultaneous detection of parenchymal, biliary, and vascular complications after liver transplantation. Fifty-two liver transplant recipients suspected to have parenchymal, biliary, and (or) vascular complications underwent our MRI protocol at 1.5T unit using a phased array coil. After preliminary acquisition of axial T 1 w and T 2 w sequences, magnetic resonance cholangiography (MRC) was performed through a breath-hold, thin- and thick-slab, single-shot T 2 w sequence in the coronal plane. Contrast-enhanced magnetic resonance angiography (CEMRA) was obtained using a 3-dimensional coronal spoiled gradient-echo sequence, which enabled acquisition of 32 partitions 2.0 mm thick. A fixed dose of 20 ml gadobenate dimeglumine was administered at 2 mL/s. A post-contrast T 1 w sequence was also performed. Two observers in conference reviewed source images and 3-dimensional reconstructions to determine the presence of parenchymal, biliary, and vascular complications. MRI findings were correlated with surgery, endoscopic retrograde cholangiography (ERC), biopsy, digital subtraction angiography (DSA), and imaging follow-up. MRI revealed abnormal findings in 32 out of 52 patients (61%), including biliary complications (anastomotic and nonanastomotic strictures, and lithiasis) in 31, vascular disease (hepatic artery stenosis and thrombosis) in 9, and evidence of hepatic abscess and hematoma in 2. ERC confirmed findings of MRC in 30 cases, but suggested disease underestimation in 2. DSA confirmed 7 magnetic resonance angiogram (MRA) findings, but suggested disease overestimation in 2. MRI combined with MRC and CEMRA can provide a comprehensive assessment of parenchymal, biliary, and vascular complications in most recipients of liver transplantation. (author)

Clinical, radiographic, and magnetic resonance imaging findings of gastrocnemius musculotendinopathy in various dog breeds.

Science.gov (United States)

Kaiser, Susanne M; Harms, Oliver; Konar, Martin; Staudacher, Anne; Langer, Anna; Thiel, Cetina; Kramer, Martin; Schaub, Sebastian; von Pückler, Kerstin H

2016-11-23

To describe clinical, radiographic, and magnetic resonance imaging (MRI) findings in 16 dogs diagnosed with gastrocnemius musculotendinopathy. Retrospective evaluation of medical records, radiographs, and MRI results, as well as follow-up completed by telephone questionnaire. Most dogs had chronic hindlimb lameness with no history of trauma or athletic activities. Clinical examination revealed signs of pain on palpation without stifle joint instability. Seven dogs had radiographic signs of osteophyte formation on the lateral fabella. Magnetic resonance imaging revealed T2 hyperintensity and uptake of contrast agent in the region of the origin of the gastrocnemius muscle. Changes were found in the lateral and medial heads of the gastrocnemius. Conservative treatment resulted in return to full function in 11 dogs. Two dogs showed partial restoration of normal function, one dog showed no improvement. Two dogs were lost to follow-up. Gastrocnemius musculotendinopathy is a potential cause of chronic hindlimb lameness in medium to large breed dogs. A history of athletic activity must not necessarily be present. Magnetic resonance imaging shows signal changes and uptake of contrast agent in the region of the origin of the gastrocnemius muscle. A combination of T1 pre- and post-contrast administration and T2 weighted sequences completed by a fat-suppressed sequence in the sagittal plane are well-suited for diagnosis. Conservative treatment generally results in return to normal function.

Incidental findings are frequent in young healthy individuals undergoing magnetic resonance imaging in brain research imaging studies

DEFF Research Database (Denmark)

Hartwigsen, Gesa; Siebner, Hartwig R; Deuschl, Günther

2010-01-01

There is an ongoing debate about how to handle incidental findings (IF) detected in healthy individuals who participate in research-driven magnetic resonance imaging (MRI) studies. There are currently no established guidelines regarding their management....

Magnetic resonance imaging findings in fatal primary cerebral infection due to Chaetomium strumarium

International Nuclear Information System (INIS)

Aribandi, M.; Bazan, C.; Rinaldi, M.G.

2005-01-01

This report describes MRI findings of a rare case of biopsy-proven fatal cerebral infection with Chaetomium strumarium in a 28-year-old man with a history of i.v. drug abuse. Magnetic resonance imaging revealed rapidly progressing lesions with irregular peripheral enhancement, possible central haemorrhage and significant mass effect. Only six cases of cerebral infection with Chaetomium have been reported in the English literature. This is the first report in the radiology literature describing the imaging findings. The previously reported cases of cerebral infection by the Chaetomium species are also reviewed Copyright (2005) Blackwell Publishing Asia Pty Ltd

Magnetic resonance imaging findings in fatal primary cerebral infection due to Chaetomium strumarium

Energy Technology Data Exchange (ETDEWEB)

Aribandi, M; Bazan, C [University of Texas Health Science Center at San Antonio, San Antonio, Texas (United States). Dept. of Radiology; Rinaldi, M G [University of Texas Health Science Center at San Antonio, San Antonio, Texas (United States). Dept. of Pathology

2005-04-15

This report describes MRI findings of a rare case of biopsy-proven fatal cerebral infection with Chaetomium strumarium in a 28-year-old man with a history of i.v. drug abuse. Magnetic resonance imaging revealed rapidly progressing lesions with irregular peripheral enhancement, possible central haemorrhage and significant mass effect. Only six cases of cerebral infection with Chaetomium have been reported in the English literature. This is the first report in the radiology literature describing the imaging findings. The previously reported cases of cerebral infection by the Chaetomium species are also reviewed Copyright (2005) Blackwell Publishing Asia Pty Ltd.

Magnetic resonance imaging findings of solitary infantile myofibromatosis of the skull: A case report

Energy Technology Data Exchange (ETDEWEB)

Lee, Seung Eun; Cho, Kil Ho; Suh, Jang Ho; Choi, Joon Hyuk [College of Medicine, Yeungnam University, Daegu (Korea, Republic of)

2016-11-15

Infantile myofibromatosis is a rare, benign mesenchymal disorder of early childhood characterized by solitary or multiple benign myofibroblastic tumors. The tumors may involve the skin, subcutaneous tissue, muscle, bone and visceral organs. We report magnetic resonance imaging findings of solitary infantile myofibromatosis arising in the temporal bone of a ten-month-old boy, and the diagnosis was confirmed by surgical excision and histopathological examination.

Prevalence of incidental findings on magnetic resonance imaging: Cuban project to map the human brain

International Nuclear Information System (INIS)

Hernandez Gonzalez, Gertrudis de los Angeles; Alvarez Sanchez, Marilet; Jordan Gonzalez, Jose

2010-01-01

To determine the prevalence of incidental findings in healthy subjects of the Cuban Human Brain Mapping Project sample, it was performed a retrospective descriptive study of the magnetic resonance imaging (MRI) obtained from 394 healthy subjects that make up the sample of the project, between 2006-2007, with an age range of 18 to 68 years (mean 33,12), of which 269 (68,27 %) are male and 125 (31,73 %) are women. It was shown that 40,36 % had one or more anomaly in the magnetic resonance imaging (MRI). In total, the number of incidental findings was 188, 23,6 % of which were brain findings and 24,11 % were non-brain findings, among the latter, were the sinusopathy with 20,81 % and maxillary polyps with 3,30 %. The most prevalent brain findings were: intrasellar arachnoidocele, 11,93 %, followed by the prominence of the pituitary gland, 5,84 %, ventricular asymmetry, 1,77 % and bone defects, 1,02 %. Other brain abnormalities found with very low prevalence had no pathological significance, except for two cases with brain tumor, which were immediately sent to a specialist. Incidental findings in MRI are common in the general population (40,36 %), being the sinusopathy, and intrasellar arachnoidocele the most common findings. Asymptomatic individuals who have any type of structural abnormality provide invaluable information on the prevalence of these abnormalities in a presumably healthy population, which may be used as references for epidemiological studies

The particle concentration effect on magnetic resonance linewidth for magnetic liquids with chain aggregates

International Nuclear Information System (INIS)

Marin, C.N.

2002-01-01

Based on the assumption of particle chains formation within a magnetic liquid, computer simulation of the magnetic resonance line is presented. The dependence on particle concentration within a magnetic liquid of magnetic resonance linewidth is analyzed. The computer simulation demonstrates that the particles chaining has an important effect on the enlargement of the magnetic resonance line. Increasing the particle concentration within magnetic liquid leads to an increase in the linewidth. The agreement with some experimental findings is discussed

Magnetic resonance enterography in pediatric celiac disease.

Science.gov (United States)

Koc, Gonca; Doganay, Selim; Sevinc, Eylem; Deniz, Kemal; Chavhan, Govind; Gorkem, Sureyya B; Karacabey, Neslihan; Dogan, Mehmet S; Coskun, Abdulhakim; Aslan, Duran

To assess if magnetic resonance enterography is capable of showing evidence/extent of disease in pediatric patients with biopsy-proven celiac disease by comparing with a control group, and to correlate the magnetic resonance enterography findings with anti-endomysial antibody level, which is an indicator of gluten-free dietary compliance. Thirty-one pediatric patients (mean age 11.7±3.1 years) with biopsy-proven celiac disease and 40 pediatric patients as a control group were recruited in the study. The magnetic resonance enterography images of both patients with celiac disease and those of the control group were evaluated by two pediatric radiologists in a blinded manner for the mucosal pattern, presence of wall thickening, luminal distention of the small bowel, and extra-intestinal findings. Patient charts were reviewed to note clinical features and laboratory findings. The histopathologic review of the duodenal biopsies was re-conducted. The mean duration of the disease was 5.6±1.8 years (range: 3-7.2 years). In 24 (77%) of the patients, anti-endomysial antibody levels were elevated (mean 119.2±66.6RU/mL). Magnetic resonance enterography revealed normal fold pattern in all the patients. Ten (32%) patients had enlarged mesenteric lymph nodes. Although a majority of the patients had elevated anti-endomysial antibody levels indicating poor dietary compliance, magnetic resonance enterography did not show any mucosal abnormality associated with the inability of magnetic resonance enterography to detect mild/early changes of celiac disease in children. Therefore, it may not be useful for the follow-up of pediatric celiac disease. Copyright © 2017 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

Magnetic resonance imaging of infectious myositis

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Yun, Ji Young; Kim, Jee Young; Kim, Sang Heum; Jung, Youn Ju; Cha, Eun Suk; Park, Joung Mi; Park, Young Ha [The Catholic Univ., College of Medicine, Suwon (Korea, Republic of)

1998-09-01

To describe the findings of magnetic resonance imaging in infectious myositis and to determine their value for differentiation between ruberculous and bacterial myositis. Magnetic resonance images of ten proven cases of infectious myositis (five tuberculous and five bacterial) were retrospectively reviewed in the light of clinical and laboratory findings. On the basis of magnetic resonance images, signal intensity of the mass, the presence or absence of an abscess, signal intensity of the peripheral wall, patterns of contrast enhancement, and associated findings were evaluated. Compared with those of bacterial myositis, the symptoms of tuberculous myositis lasted longer but there were no difinite local inflammatory signs. In three of five cases of bacterial myositis there were specific medical records;trauma in two cases and systemic lupus erythematosus in one. All tuberculous myositis cases involved a single muscle, but bacterial myositis affected multipe muscles in three cases(60%). All but one case showed a mass in the involved muscles. In one bacterial case, there was diffuse swelling in the involved muscle. On T1-weighted images, eight infectious cases showed low signal intensity;two, of the bactrerial type, showed subtle increased signal intensity. all cases demonstrated high signal intensity on t2-weighted images. The signal intensity of peripheral wall was slightly increased on T1-weighted images, but low on T2-weighted. In four cases there was associated cellulitis, and in one case each, adjacent joint effusion and deep vein thrombosis were seen. After gadolinium infusion, peripheral rim enhancement was noted in nine cases and heterogeneous enhancement in one. After magnetic resonance imaging of infectious myositis, the characteristic finding was an abscessed lesion, with the peripheral wall showing high signal intensity on T1-weighted images and low signal intensity on T2 weighted. Although we found it difficult to differentiate bacterial from tuberculous

Magnetic resonance imaging of infectious myositis

International Nuclear Information System (INIS)

Yun, Ji Young; Kim, Jee Young; Kim, Sang Heum; Jung, Youn Ju; Cha, Eun Suk; Park, Joung Mi; Park, Young Ha

1998-01-01

To describe the findings of magnetic resonance imaging in infectious myositis and to determine their value for differentiation between ruberculous and bacterial myositis. Magnetic resonance images of ten proven cases of infectious myositis (five tuberculous and five bacterial) were retrospectively reviewed in the light of clinical and laboratory findings. On the basis of magnetic resonance images, signal intensity of the mass, the presence or absence of an abscess, signal intensity of the peripheral wall, patterns of contrast enhancement, and associated findings were evaluated. Compared with those of bacterial myositis, the symptoms of tuberculous myositis lasted longer but there were no difinite local inflammatory signs. In three of five cases of bacterial myositis there were specific medical records;trauma in two cases and systemic lupus erythematosus in one. All tuberculous myositis cases involved a single muscle, but bacterial myositis affected multipe muscles in three cases(60%). All but one case showed a mass in the involved muscles. In one bacterial case, there was diffuse swelling in the involved muscle. On T1-weighted images, eight infectious cases showed low signal intensity;two, of the bactrerial type, showed subtle increased signal intensity. all cases demonstrated high signal intensity on t2-weighted images. The signal intensity of peripheral wall was slightly increased on T1-weighted images, but low on T2-weighted. In four cases there was associated cellulitis, and in one case each, adjacent joint effusion and deep vein thrombosis were seen. After gadolinium infusion, peripheral rim enhancement was noted in nine cases and heterogeneous enhancement in one. After magnetic resonance imaging of infectious myositis, the characteristic finding was an abscessed lesion, with the peripheral wall showing high signal intensity on T1-weighted images and low signal intensity on T2 weighted. Although we found it difficult to differentiate bacterial from tuberculous

Extra-intestinal findings on magnetic resonance enterography in children with inflammatory bowel disease

International Nuclear Information System (INIS)

Sheybani, E.F.; Sheikh, N.; Chavhan, G.B.; Greer, M.-L.C.

2016-01-01

Aim: To determine the occurrence of extra-intestinal findings on magnetic resonance enterography (MRE) in a large cohort of children with known or suspected inflammatory bowel disease, characterise those findings, determine the technique and frequency of follow-up imaging, and associated costs. Materials and methods: Imaging reports from 757 MRE examinations in 671 children with known or suspected IBD from 2011 through 2012 were analysed retrospectively. Reported extra-intestinal findings were categorised by two radiologists in consensus as normal, normal variants or commonly seen findings without clinical significance, or abnormal. Prior imaging reports of the patients with abnormal findings were reviewed to identify which findings were new or substantially changed. Subsequent imaging examinations, their associated costs, and additional work-up of extra-intestinal findings were recorded in each group. Results: A total of 403 extra-intestinal findings were reported in 290 MRE (38.3%) examinations performed in 269 children (40.1%). Of these, 189 (46.9%) findings were abnormal and new or significantly changed from prior imaging, 88 (21.8%) were abnormal and stable, 50 (12.4%) were normal variants or commonly seen findings with no clinical significance, and 76 (18.9%) were normal. Abnormal findings included 34.7% associated with IBD and 65.3% considered unrelated. Follow-up imaging was performed for 69 (17.1%) mostly abnormal findings in 94 patients (8.3%). Magnetic resonance imaging (51%) and ultrasound (28%) were the most commonly utilised imaging methods. Conclusion: MRE identifies a large number of previously unknown extra-intestinal abnormalities in children with known or suspected IBD, most unrelated to IBD. Although <10% of children having MRE undergo subsequent imaging of extra-intestinal abnormalities, given the rapid uptake of MRE in the paediatric population, emphasis should be given to avoiding techniques utilising ionising radiation at follow

Non-cardiac findings on coronary computed tomography and magnetic resonance imaging

International Nuclear Information System (INIS)

Dewey, Marc; Schnapauff, Dirk; Teige, Florian; Hamm, Bernd

2007-01-01

Both multislice computed tomography (CT) and magnetic resonance imaging (MRI) are emerging as methods to detect coronary artery stenoses and assess cardiac function and morphology. Non-cardiac structures are also amenable to assessment by these non-invasive tests. We investigated the rate of significant and insignificant non-cardiac findings using CT and MRI. A total of 108 consecutive patients suspected of having coronary artery disease and without contraindications to CT and MRI were included in this study. Significant non-cardiac findings were defined as findings that required additional clinical or radiological follow-up. CT and MR images were read independently in a blinded fashion. CT yielded five significant non-cardiac findings in five patients (5%). These included a pulmonary embolism, large pleural effusions, sarcoid, a large hiatal hernia, and a pulmonary nodule (>1.0 cm). Two of these significant non-cardiac findings were also seen on MRI (pleural effusions and sarcoid, 2%). Insignificant non-cardiac findings were more frequent than significant findings on both CT (n = 11, 10%) and MRI (n = 7, 6%). Incidental non-cardiac findings on CT and MRI of the coronary arteries are common, which is why images should be analyzed by radiologists to ensure that important findings are not missed and unnecessary follow-up examinations are avoided. (orig.)

Non-cardiac findings on coronary computed tomography and magnetic resonance imaging

Energy Technology Data Exchange (ETDEWEB)

Dewey, Marc; Schnapauff, Dirk; Teige, Florian; Hamm, Bernd [Charite-Universitaetsmedizin Berlin, Humboldt-Universitaet zu Berlin, Department of Radiology, Chariteplatz 1, P.O. Box 10098, Berlin (Germany)

2007-08-15

Both multislice computed tomography (CT) and magnetic resonance imaging (MRI) are emerging as methods to detect coronary artery stenoses and assess cardiac function and morphology. Non-cardiac structures are also amenable to assessment by these non-invasive tests. We investigated the rate of significant and insignificant non-cardiac findings using CT and MRI. A total of 108 consecutive patients suspected of having coronary artery disease and without contraindications to CT and MRI were included in this study. Significant non-cardiac findings were defined as findings that required additional clinical or radiological follow-up. CT and MR images were read independently in a blinded fashion. CT yielded five significant non-cardiac findings in five patients (5%). These included a pulmonary embolism, large pleural effusions, sarcoid, a large hiatal hernia, and a pulmonary nodule (>1.0 cm). Two of these significant non-cardiac findings were also seen on MRI (pleural effusions and sarcoid, 2%). Insignificant non-cardiac findings were more frequent than significant findings on both CT (n = 11, 10%) and MRI (n = 7, 6%). Incidental non-cardiac findings on CT and MRI of the coronary arteries are common, which is why images should be analyzed by radiologists to ensure that important findings are not missed and unnecessary follow-up examinations are avoided. (orig.)

Magnetic resonance findings in arrhythmogenic dysplasia of right ventricle

International Nuclear Information System (INIS)

Ramiro, E.; Villacastin, B. P.; Farre, J.

1999-01-01

To compare the magnetic resonance (MR) findings in patients with arrhythmogenic dysplasia of right ventricle (ADRV) with the images of right ventricle (RV) presenting normal morphology. Three groups of patients were studied by MR: a) a group of 20 healthy volunteers; b) 22 patients with ADRV diagnosed by other methods; and c) 11 patients presenting right ventricular tachycardia (VT) with no evidence of ADRV. When compared with the other two groups, the patients with ADRV were found to have an enlarged right atrium and RV, one wall of RV abnormally thin, changes in the myocardial signal and significant left ventricular involvement. MR is a noninvasive method that is useful in the assessment of RV dilation, ventricular wall thinning, deformities and sacculations and in the detection of changes in the myocardial MR signal produced by the replacement. It aids in the localization, characterization and quantification of morphological changes in RV. (Author) 36 refs

Brain magnetic resonance findings in infective endocarditis with neurological complications

International Nuclear Information System (INIS)

Azuma, Asako; O'uchi, Toshihiro; Toyoda, Keiko

2009-01-01

Diagnosing infective endocarditis and its complications can be difficult because of the nonspecific symptoms. We reviewed findings of intracranial abnormalities on magnetic resonance imaging (MRI) in 14 patients with neurological complications and herein discuss the overall intracranial MRI findings. We retrospectively reviewed patients with infective endocarditis from August 2004 to August 2006. Brain MRI, the causative bacteria, and abnormal neurological symptoms were reviewed for 14 patients with neurological complications. Of the 14 patients, 13 showed intracranial abnormalities on MRI. Embolization was seen in 10 patients, hemorrhage in 3, abscess formation in 3, and encephalitis in 2. Hyperintense lesions with a central hypointense area on T2-weighted and/or T2*-weighted imaging (Bull's-eye-like lesion) were seen in four patients. A combination of these intracranial abnormalities was observed in 6 patients. The MRI findings associated with infective endocarditis are wide-ranging: embolization, hemorrhage, meningitis, cerebritis, abscess, the bull's-eye-like lesion. Clinicians should consider the possibility of infective endocarditis in patients with unknown fever and neurological abnormality. Brain MRI should be promptly performed for those patients, and T2*-weighted imaging is recommended for an early diagnosis of infective endocarditis. (author)

Osteomas of the skull. Comparison of magnetic resonance imaging and histological findings

Energy Technology Data Exchange (ETDEWEB)

Shibata, Yasushi; Matsumura, Akira; Yoshii, Yoshihiko; Nose, Tadao [Tsukuba Univ., Ibaraki (Japan). Inst. of Clinical Medicine

1995-01-01

Magnetic resonance (MR) images of five patients with osteomas of the skull and six patients with other primary skull tumors were reviewed. All osteomas appeared as low-intensity areas on T{sub 1}-weighted images. T{sub 2}-weighted images showed homogeneous low-intensity areas in two dense osteomas, a high-intensity area in one spongy osteoma, and mixed intensity areas in two mixed spongy and dense osteomas, respectively. The signal intensities of osteomas on T{sub 2}-weighted MR images correlated well with the histological findings. Other skull tumors showed no specific MR imaging appearance. (author).

Magnetic resonance findings associated with intracranial hypotension. A report of three cases occurring after lumbar puncture

International Nuclear Information System (INIS)

Galan, J.; Vuelta, R. V.; Oleaga, L.; Grande, D.

1999-01-01

The magnetic resonance (MR) findings are presented for three patients who developed intracranial hypotension syndrome following lumbar puncture, one of the most common causes of this complication. All three patients presented the MR findings characteristically associated with this event, consisting of diffuse dural enhancement after administration of a paramagnetic contrast medium, as well as extraaxial collection that played either an accompanying or a causative role. (Author) 7 refs

Magnetic resonance imaging in clinically-definite multiple sclerosis

International Nuclear Information System (INIS)

Noakes, J.B.; Herkes, G.K.; Frith, J.A.

1990-01-01

Forty-two patients with clinically-definite multiple sclerosis were examined by magnetic resonance imaging using a 1.5-T instrument. Magnetic resonance imaging detected an abnormality in 90% of patients. In four patients, no lesions were demonstrated. The number, size and site of the lesions by magnetic resonance imaging were compared with the patients' clinical status and other variables. The Kurtzke disability status scale score increased in patients with corpus callosum atrophy, brainstem and basal ganglia lesions, and correlated with the total number of lesions. No correlation was shown between the findings of magnetic resonance imaging and disease duration, age, sex or pattern-reversal visual-evoked potentials. The variety of magnetic resonance images that could be obtained in patients with clinically-definite multiple sclerosis is highlighted. 24 refs., 8 figs., 1 tab

Magnetic resonance findings in skeletal muscle tears

International Nuclear Information System (INIS)

De Smet, A.A.

1993-01-01

Magnetic resonance (MR) images of skeletal muscle tears can clearly delineate the severity of muscle injury. Although MR imaging is seldom necessary in patients with acute musle trauma, it can be helpful in deciding on clinical management. The two major MR findings in acute muscle tears are deformity of the muscle and the presence of abnormal signal reflecting hemorrhage and edema. In acute tears, methemoglobin within the extravascular blood causes high-signal areas on both T1- and T2-weighted images. With partial tears, the blood may dissect in a distinctive linear pattern along the muscle bundles and fibers. As healing begins, the muscle signal diminishes, first on the T1-weighted images and then on the T2-weighted images. When there is residual abnormal signal on images obtained more than several months after the injury, it is presumed to represent hemorrhage from recurrent tears. In patients with a questionable history of a remote injury, the clinical presentation may be that of persistent pain or a soft tissue mass. In these cases MR imaging may identify the cause of the pain and can exclude a neoplasm by proving that the mass is a hypertrophied or retracted musle. Thus, MR imaging has a limited, but occasionally important role in selected patients with skeletal muscle tears. (orig.)

Brain Magnetic Resonance Imaging Findings in Developmentally Delayed Children

Directory of Open Access Journals (Sweden)

Ali Akbar Momen

2011-01-01

Full Text Available Background. Developmental disorders are failure or inability to acquire various age-specific skills at expected maturational age, which affects about 5–10% of preschool children. One of the most important methods for evaluation of developmentally delayed children is neuroimaging, especially, brain magnetic resonance imaging (MRI that provides useful information regarding brain tissue structures and anomalies. Method and Material. In this study, hospital records of 580 developmentally delayed children (aged 2 months to 15 years who admitted in pediatric ward of Golestan Hospital from 1997 to 2009 were selected. Information such as age, MRI findings were collected in the questionnaire and statistically analyzed. Results. Total, 580 children including 333 males (57.4% and 247 females (42.6% were studied. Abnormal brain MRI was observed in 340 (58.6% cases (204 Males, 136 females. The finding includes nonspecific in 38 (6.6%, congenital and developmental anomalies of brain in 39 (6.7%, recognizable syndromes in 3 (0.5%, neurovascular diseases or trauma in 218 (37.6%, and metabolic or neurodegenerative diseases in 42 (7.2% cases. Conclusion. Because 60% of all study groups showed abnormal brain MRI, using this method could be effective in diagnosis, management, and almost prognosis determination processes.

Magnetic resonance imaging and clinical findings in a miniature Schnauzer with hypodipsic hypernatremia

International Nuclear Information System (INIS)

Shimokawa Miyama, Takako; Iwamoto, Emiko; Umeki, Saori; Nakaichi, Munekazu; Okuda, Masaru; Mizuno, Takuya

2009-01-01

A 6-month-old miniature Schnauzer presented with hypernatremia and clinical signs of vomiting, diarrhea, inappetence, and lethargy. The dog did not consume water on its own. Hypernatremia and the related clinical signs were resolved by fluid administration. Endocrinological investigations and urinalysis excluded the possibility of diabetes insipidus and hyperaldosteronism. Therefore, the dog was diagnosed with hypodipsic hypernatremia. Magnetic resonance imaging revealed dysgenesis of the corpus callosum and other forebrain structures. On the basis of these findings, congenital brain malformation associated with failure of the osmoreceptor system was suspected. (author)

Magnetic resonance imaging and clinical findings in a miniature Schnauzer with hypodipsic hypernatremia.

Science.gov (United States)

Shimokawa Miyama, Takako; Iwamoto, Emiko; Umeki, Saori; Nakaichi, Munekazu; Okuda, Masaru; Mizuno, Takuya

2009-10-01

A 6-month-old miniature Schnauzer presented with hypernatremia and clinical signs of vomiting, diarrhea, inappetence, and lethargy. The dog did not consume water on its own. Hypernatremia and the related clinical signs were resolved by fluid administration. Endocrinological investigations and urinalysis excluded the possibility of diabetes insipidus and hyperaldosteronism. Therefore, the dog was diagnosed with hypodipsic hypernatremia. Magnetic resonance imaging revealed dysgenesis of the corpus callosum and other forebrain structures. On the basis of these findings, congenital brain malformation associated with failure of the osmoreceptor system was suspected.

Inhalant-Abuse Myocarditis Diagnosed by Cardiac Magnetic Resonance.

Science.gov (United States)

Dinsfriend, William; Rao, Krishnasree; Matulevicius, Susan

2016-06-01

Multiple reports of toxic myocarditis from inhalant abuse have been reported. We now report the case of a 23-year-old man found to have toxic myocarditis from inhalation of a hydrocarbon. The diagnosis was made by means of cardiac magnetic resonance imaging with delayed enhancement. The use of cardiac magnetic resonance to diagnose myocarditis has become increasingly common in clinical medicine, although there is not a universally accepted criterion for diagnosis. We appear to be the first to document a case of toxic myocarditis diagnosed by cardiac magnetic resonance. In patients with a history of drug abuse who present with clinical findings that suggest myocarditis or pericarditis, cardiac magnetic resonance can be considered to support the diagnosis.

Magnetic resonance spectroscopy as a diagnostic modality for carcinoma thyroid

International Nuclear Information System (INIS)

Gupta, Nikhil; Kakar, Arun K.; Chowdhury, Veena; Gulati, Praveen; Shankar, L. Ravi; Vindal, Anubhav

2007-01-01

Aim: The aim of this study was to observe the findings of magnetic resonance spectroscopy of solitary thyroid nodules and its correlation with histopathology. Materials and methods: In this study, magnetic resonance spectroscopy was carried out on 26 patients having solitary thyroid nodules. Magnetic resonance spectroscopy (MRS) was performed on a 1.5 T super conductive system with gradient strength of 33 mTs. Fine needle aspiration cytology was done after MRS. All 26 patients underwent surgery either because of cytopathologically proven malignancy or because of cosmetic reasons. Findings of magnetic resonance spectroscopy were compared with histopathology of thyroid specimens. Results and conclusion: It was seen that presence or absence of choline peak correlates very well with presence or absence of malignant foci with in the nodule (sensitivity = 100%; specificity = 88.88%). These results indicate that magnetic resonance spectroscopy may prove to be an useful diagnostic modality for carcinoma thyroid

Magnetic resonance in prenatal diagnosis of thoracic anomalies

International Nuclear Information System (INIS)

Pietrani, M.; Elias, D.; Wojakowski, A.; Fataljaef, V.; Carcano, M.; Otano, L.

2007-01-01

The objective of this article is to communicate the experience in the evaluation of fetal anomalies thoracic by means of magnetic resonance. Between January, 2001 - March, 2007 16 fetus were evaluated by means of magnetic resonance with echographic diagnosis of thoracic anomalies. An equipment of 1.5 TESLA was used. The thoracic anatomy was valued in general. At the presence of discovering pulmonary mass, their size, volume and intensity of sign were determined. The echographic and magnetic resonance findings were checked against the perinatal results [es

Magnetic resonance imaging in the evaluation of periosteal reactions

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Nogueira-Barbosa, Marcello Henrique; Trad, Clovis Simao; Muglia, Valdair Francisco; Elias Junior, Jorge; Simao, Marcelo Novelino, E-mail: marcello@fmrp.usp.b [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Centro de Ciencias das Imagens e Fisica Medica; Sa, Jose Luiz de [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Hospital das Clinicas; Oliveira, Rodrigo Cecilio Vieira de [Clinica de Diagnostico por Imagem Tomoson, Aracatuba, SP (Brazil); Engel, Edgard Eduard [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Dept. de Biomecanica, Medicina e Reabilitacao do Aparelho Locomotor

2010-07-15

The objective of the present essay was to encourage a careful evaluation of periosteal reactions on magnetic resonance images. The initial approach to bone lesions is made by conventional radiography and, based on the imaging findings, periosteal reactions are classified into classical subtypes. Although magnetic resonance imaging is considered as the gold standard for local staging of bone tumors, the utilization of such method in the study of periosteal reactions related to focal bone lesions has been poorly emphasized, with relatively few studies approaching this subject. The literature review revealed a study describing an experimental animal model of osteomyelitis suggesting that magnetic resonance imaging is superior to other imaging methods in the early identification of periosteal reactions. Another study has suggested a good correlation between conventional radiography and magnetic resonance imaging in the identification and classification of periosteal reactions in cases of osteosarcoma. The present essay illustrates cases of periosteal reactions observed at magnetic resonance imaging in correlation with findings of conventional radiography or other imaging methods. (author)

Magnetic resonance imaging in the evaluation of periosteal reactions

International Nuclear Information System (INIS)

Nogueira-Barbosa, Marcello Henrique; Trad, Clovis Simao; Muglia, Valdair Francisco; Elias Junior, Jorge; Simao, Marcelo Novelino; Engel, Edgard Eduard

2010-01-01

The objective of the present essay was to encourage a careful evaluation of periosteal reactions on magnetic resonance images. The initial approach to bone lesions is made by conventional radiography and, based on the imaging findings, periosteal reactions are classified into classical subtypes. Although magnetic resonance imaging is considered as the gold standard for local staging of bone tumors, the utilization of such method in the study of periosteal reactions related to focal bone lesions has been poorly emphasized, with relatively few studies approaching this subject. The literature review revealed a study describing an experimental animal model of osteomyelitis suggesting that magnetic resonance imaging is superior to other imaging methods in the early identification of periosteal reactions. Another study has suggested a good correlation between conventional radiography and magnetic resonance imaging in the identification and classification of periosteal reactions in cases of osteosarcoma. The present essay illustrates cases of periosteal reactions observed at magnetic resonance imaging in correlation with findings of conventional radiography or other imaging methods. (author)

Magnetic resonance imaging of muscle tears

International Nuclear Information System (INIS)

De Smet, A.A.; Fisher, D.R.; Heiner, J.P.; Keene, J.S.

1990-01-01

Magnetic resonance scans were obtained on 17 patients with acute, subacute, or chronic muscle tears. These patients presented with complaints of persistent pain or a palpable mass. Magnetic resonance findings were characterized according to alterations in muscle shape and the presence of abnormal high signal within the injured muscle. These areas of high signal were noted on both T1-weighted and T2-weighted scans and were presumed to represent areas of intramuscular hemorrhage. (orig.)

Magnetic Resonance Imaging Findings in Chronic Carbon Monoxide Intoxication

Energy Technology Data Exchange (ETDEWEB)

Durak, A. C.; Coskun, A.; Yikilmaz, A.; Erdogan, F.; Mavili, E.; Guven, M. [Hospital of Erciyes Univ., Kayseri (Turkey). Dept. of Radiology

2005-05-01

Purpose: To define the cranial magnetic resonance imaging (MRI) features of the chronic stage of carbon monoxide (CO) poisoning in patients with and without neuropsychiatric sequelae. Material and Methods: Eight patients who had neither symptoms nor neurological sequelae and eight patients with neuropsychiatric sequelae were included in the study. Patients aged between 9 to 57 (mean 32.2 years). All patients had been comatose at initial admittance and awoke after normobaric 100% oxygen therapy within 1-7 days. In this study, the patients were being examined with routine cranial MRI between 1 and 10 years (mean 3.4 years) after exposure to CO. Results: The most common finding was bilateral symmetric hyperintensity of the white matter, which was more significant in the centrum semiovale, with relative sparing of the temporal lobes and anterior parts of the frontal lobes on T2-weighted and FLAIR images in all patients. Cerebral cortical atrophy was seen in 10 patients; mild atrophy of cerebellar hemispheres in 8; and vermian atrophy in 11. Corpus callosum was atrophic in one patient. Bilateral globus pallidus lesions were seen in three patients. The lesions were hypointense on T1-weighted images and hyperintense on T2-weighted and FLAIR images. Conclusion: Patients with severe CO intoxication may develop persistent cerebral changes independently of their neuropsychiatric findings in the chronic stage. They may present with characteristic MRI findings as described here, even if asymptomatic. The history of CO exposure is therefore helpful for recognizing and interpreting the MRI findings of chronic stage CO intoxication.

Correlation of magnetic resonance imaging findings of spinal intradural extramedullary schwannomas with pathologic findings

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Kim, Yeo Ju; Park, In Suh; Yoon, Seung Hwan; Choi, Suk Jin; Kim, Youn Jeong; Kang, Young Hye; Lee, Ha Young; Kim, Woo Chul; Han, Jun Gu; Cho, Soon Gu [Inha University Hospital, Incheon (Korea, Republic of)

2015-06-15

To evaluate the magnetic resonance imaging (MRI) findings of spinal intradural extramedullary schwannomas with pathologic correlation and to determine whether these schwannomas share the imaging features of schwannomas in the peripheral nerves. The MRIs of 17 cases of pathologically proven spinal intradural extramedullary schwannomas were reviewed retrospectively, and cystic changes, enhancement, and intratumoral hemorrhage of the tumors were evaluated. Imaging features known to be common findings of schwannoma in the peripheral nerves, such as encapsulation, the target sign, the fascicular sign, and visualization of entering or exiting nerve rootlets, were also evaluated. The histopathology of the tumors was correlated with the MRI findings. Cystic changes were detected in 14 cases by MRI and in 16 cases by pathology. The most common pattern of enhancement was a thick peripheral septal pattern (70.59%). Intratumoral hemorrhage was detected in four cases on MRI, but in all cases on pathology. Encapsulation was observed in all cases. The fascicular sign was seen in only four cases, and thickening of an exiting rootlet was visualized in one case. None of the cases showed the target sign. Spinal intradural extramedullary schwannomas were typical encapsulated cystic tumors and had few imaging features of schwannomas in the peripheral nerves.

MRI (Magnetic Resonance Imaging)

Science.gov (United States)

... Procedures Medical Imaging MRI (Magnetic Resonance Imaging) MRI (Magnetic Resonance Imaging) Share Tweet Linkedin Pin it More sharing options Linkedin Pin it Email Print Magnetic Resonance Imaging (MRI) is a medical imaging procedure for ...

Bifurcation magnetic resonance in films magnetized along hard magnetization axis

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Vasilevskaya, Tatiana M., E-mail: t_vasilevs@mail.ru [Ulyanovsk State University, Leo Tolstoy 42, 432017 Ulyanovsk (Russian Federation); Sementsov, Dmitriy I.; Shutyi, Anatoliy M. [Ulyanovsk State University, Leo Tolstoy 42, 432017 Ulyanovsk (Russian Federation)

2012-09-15

We study low-frequency ferromagnetic resonance in a thin film magnetized along the hard magnetization axis performing an analysis of magnetization precession dynamics equations and numerical simulation. Two types of films are considered: polycrystalline uniaxial films and single-crystal films with cubic magnetic anisotropy. An additional (bifurcation) resonance initiated by the bistability, i.e. appearance of two closely spaced equilibrium magnetization states is registered. The modification of dynamic modes provoked by variation of the frequency, amplitude, and magnetic bias value of the ac field is studied. Both steady and chaotic magnetization precession modes are registered in the bifurcation resonance range. - Highlights: Black-Right-Pointing-Pointer An additional bifurcation resonance arises in a case of a thin film magnetized along HMA. Black-Right-Pointing-Pointer Bifurcation resonance occurs due to the presence of two closely spaced equilibrium magnetization states. Black-Right-Pointing-Pointer Both regular and chaotic precession modes are realized within bifurcation resonance range. Black-Right-Pointing-Pointer Appearance of dynamic bistability is typical for bifurcation resonance.

Bifurcation magnetic resonance in films magnetized along hard magnetization axis

International Nuclear Information System (INIS)

Vasilevskaya, Tatiana M.; Sementsov, Dmitriy I.; Shutyi, Anatoliy M.

2012-01-01

We study low-frequency ferromagnetic resonance in a thin film magnetized along the hard magnetization axis performing an analysis of magnetization precession dynamics equations and numerical simulation. Two types of films are considered: polycrystalline uniaxial films and single-crystal films with cubic magnetic anisotropy. An additional (bifurcation) resonance initiated by the bistability, i.e. appearance of two closely spaced equilibrium magnetization states is registered. The modification of dynamic modes provoked by variation of the frequency, amplitude, and magnetic bias value of the ac field is studied. Both steady and chaotic magnetization precession modes are registered in the bifurcation resonance range. - Highlights: ► An additional bifurcation resonance arises in a case of a thin film magnetized along HMA. ► Bifurcation resonance occurs due to the presence of two closely spaced equilibrium magnetization states. ► Both regular and chaotic precession modes are realized within bifurcation resonance range. ► Appearance of dynamic bistability is typical for bifurcation resonance.

Clinicopathologic Features and Magnetic Resonance Imaging Findings in 24 Cats With Histopathologically Confirmed Neurologic Feline Infectious Peritonitis.

Science.gov (United States)

Crawford, A H; Stoll, A L; Sanchez-Masian, D; Shea, A; Michaels, J; Fraser, A R; Beltran, E

2017-09-01

Feline infectious peritonitis (FIP) is the most common infectious central nervous system (CNS) disease in the cat and is invariably fatal. Improved means of antemortem diagnosis is required to facilitate clinical decision making. Information regarding the magnetic resonance imaging (MRI) findings of neurologic FIP currently is limited, resulting in the need for better descriptions to optimize its use as a diagnostic tool. To describe the clinicopathologic features and MRI findings in cases of confirmed neurologic FIP. Twenty-four client-owned cats with histopathologic confirmation of neurologic FIP. Archived records from 5 institutions were retrospectively reviewed to identify cases with confirmed neurologic FIP that had undergone antemortem MRI of the CNS. Signalment, clinicopathologic, MRI, and histopathologic findings were evaluated. Three distinct clinical syndromes were identified: T3-L3 myelopathy (3), central vestibular syndrome (7), and multifocal CNS disease (14). Magnetic resonance imaging abnormalities were detected in all cases, including meningeal contrast enhancement (22), ependymal contrast enhancement (20), ventriculomegaly (20), syringomyelia (17), and foramen magnum herniation (14). Cerebrospinal fluid was analysed in 11 cases; all demonstrated a marked increase in total protein concentration and total nucleated cell count. All 24 cats were euthanized with a median survival time of 14 days (range, 2-115) from onset of clinical signs. Histopathologic analysis identified perivascular pyogranulomatous infiltrates, lymphoplasmacytic infiltrates, or both affecting the leptomeninges (16), choroid plexuses (16), and periventricular parenchyma (13). Magnetic resonance imaging is a sensitive means of detecting neurologic FIP, particularly in combination with a compatible signalment, clinical presentation, and CSF analysis. Copyright © 2017 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American

Concepts and indications of abdominal magnetic resonance

International Nuclear Information System (INIS)

Murillo Viera, Wendy

2012-01-01

A literature review and conceptualization was performed of the main indications of magnetic resonance studies of the abdomen and the characteristic findings for each sequence, according to organ and pathology. The radiologist has had in mind main indications for magnetic resonance studies of the abdomen, with the purpose to guide the clinician in the choice of imaging modality that works best for the patient at diagnosis [es

Nuclear magnetic resonance

International Nuclear Information System (INIS)

Ethier, R.; Melanson, D.; Peters, T.M.

1983-01-01

Ten years following computerized tomography, a new technique called nuclear magnetic resonance revolutionizes the field of diagnostic imaging. A major advantage of nuclear magnetic resonance is that the danger of radiation is non-existent as compared to computerized tomography. When parts of the human body are subject to radio-frequencies while in a fixed magnetic field, its most detailed structures are revealed. The quality of images, the applications, as well as the indications are forever increasing. Images obtained at the level of the brain and spinal cord through nuclear magnetic resonance supercede those obtained through computerized tomography. Hence, it is most likely that myelography, along with pneumoencephalography will be eliminated as a diagnostic means. It is without a doubt that nuclear magnetic resonance is tomorrow's computerized tomography [fr

Elastofibroma dorsi: magnetic resonance imaging findings in two cases

OpenAIRE

KARAGÜLLE, A. Tuba; ERDEN, M.İlhan; ERDEN, Ayşe; KARADAĞ, Demet

2002-01-01

Elastofibroma dorsi is a pseudotumoral mass of unknown pathogenesis that is usually seen in elderly patients. We report two cases of histologically proven elastofibroma dorsi, each presenting with painful periscapular masses. Magnetic resonance imagingshowed periscapular tumoral mass with low to intermediate signal intensity with interspersed areas of high signal intensity on both T1 and T2 weighted images. After I.V. administration of gadopentate dimeglumine, these lesions demonstrated mild ...

Magnetic resonance imaging findings of a metastatic chemodectoma in a dog : clinical communication

Directory of Open Access Journals (Sweden)

S.H. Naudé

2006-06-01

Full Text Available A 6-year-old, male, Collie-cross was presented with a non-weight bearing right thoracic limb lameness, right m.deltoideus, m.infraspinatus and m.supraspinatus atrophy, and severe neck pain with spasm of the cervical epaxial muscles. MRI revealed complete destruction of the 5th and 6th cervical vertebral bodies with lateral extradural spinal cord compression at the level of the 4th and 5th cervical vertebrae. These lesions were very clearly demonstrated on magnetic resonance images, while only subtle changes were seen on survey radiographs. Post mortem investigation revealed a large heart base chemodectoma with multiple smaller tumours in the cranial mediastinum and a single tumour nodule on the thoracic aorta. The 5th cervical vertebral body had necrotic, haemorrhagic and lytic changes. Histopathology of the heart base tumour, the nodules in the cranial mediastinum and on the thoracic aorta and samples from the 5th cervical vertebra confirmed the presence of a malignant aortic or carotid body tumour originating from the chemoreceptor organs. Diagnostic imaging features and post mortem findings are described. To our knowledge, this is the first report of the magnetic resonance features of a metastatic chemodectoma in a dog.

Magnetic resonance imaging apparatus

International Nuclear Information System (INIS)

Ehnholm, G.J.

1991-01-01

This patent describes an electron spin resonance enhanced magnetic resonance (MR) imaging (ESREMRI) apparatus able to generate a primary magnetic field during periods of nuclear spin transition excitation and magnetic resonance signal detection. This allows the generation of ESREMRI images of a subject. A primary magnetic field of a second and higher value generated during periods of nuclear spin transition excitation and magnetic resonance signal detection can be used to generate conventional MR images of a subject. The ESREMRI and native MR images so generated may be combined, (or superimposed). (author)

Contrast-enhanced dynamic magnetic resonance imaging findings of hepatocellular carcinoma and their correlation with histopathologic findings

Energy Technology Data Exchange (ETDEWEB)

Karahan, Okkes I. [Department of Radiology, Erciyes University Medical Faculty, PK: 18 Talas 38280, Kayseri (Turkey)]. E-mail: oikarahan@yahoo.com; Yikilmaz, Ali [Department of Radiology, Erciyes University Medical Faculty, PK: 18 Talas 38280, Kayseri (Turkey); Artis, Tarik [Department of General Surgery, Erciyes University Medical Faculty, PK: 18 Talas 38280, Kayseri (Turkey); Canoz, Ozlem [Department of Pathology, Erciyes University Medical Faculty, PK: 18 Talas 38280, Kayseri (Turkey); Coskun, Abdulhakim [Department of Radiology, Erciyes University Medical Faculty, PK: 18 Talas 38280, Kayseri (Turkey); Torun, Edip [Department of Internal Medicine, Division of Gastrenterology, Erciyes University Medical Faculty, PK: 18 Talas 38280, Kayseri (Turkey)

2006-03-15

Purpose: To investigate the correlations of contrast-enhanced magnetic resonance (MR) imaging findings of large (>5 cm) hepatocellular carcinomas with tumor size and histopathologic findings. Materials and methods: MR imaging was performed in 30 patients with a histopathologic diagnosis of hepatocellular carcinoma. The imaging protocol included non-contrast, hepatic arterial, portal venous and late phases. The signal intensities relative to the liver, enhancement patterns and the morphologic features of the lesions were evaluated in relation to size and degree of differentiation. Results: On histopathologic examination, 12 of 30 (40%) tumors were well-differentiated (grade 1), 6 of 30 (20%) were moderately differentiated (grades 2 and 3) and 12 of 30 (40%) were poorly differentiated (grade 4). Tumor size, tumor boundary, serum alpha-fetoprotein level and portal vein invasion were found to have statistically significant correlations with the degree of differentiation (p < 0.05). Portal vein invasion, capsule formation and tumor surface characteristics showed statistically significant correlations with tumor size (p < 0.05). Conclusion: MR imaging findings of hepatocellular carcinomas larger than 5 cm are partially dependent on tumor size and degree of differentiation.

A tumefactive multiple sclerosis lesion in the brain: An uncommon site with atypical magnetic resonance image findings

Energy Technology Data Exchange (ETDEWEB)

Jeong, Min Sun; Kim, Hyun Sook; Kim, Jae Hoon; Kim, Eun Kyung; Choi, Yun Sun [Eulji Hospital, Eulji University, Seoul (Korea, Republic of)

2013-11-15

Tumefactive multiple sclerosis (MS) is a rare type of demyelinating disease. Typical magnetic resonance (MR) image findings show incomplete ring enhancement with a mild mass effect. This lesion is otherwise indistinguishable from other mass-like lesions in the brain. Knowledge of the MR imaging findings for tumefactive MS is thus helpful for correct diagnosis and appropriate therapy. In this report we describe the MR image findings for pathology-confirmed tumefactive MS in an uncommon location, alongside a discussion of its aggressive features.

Characterization of human breast disease using phosphorus magnetic resonance spectroscopy and proton magnetic resonance imaging

International Nuclear Information System (INIS)

Merchant, T.E.

1992-01-01

This thesis provides the fundamental characterization and differentiation of breast tissues using in vivo and ex vivo MR techniques in the hope that these techniques and experimental findings will be used on a larger scale and in a predictive manner in order to improve the specificity of diagnosis and treatment of breast cancer. In this dissertation, clinical studies were performed using proton magnetic resonance imaging and phosphorus magnetic resonance spectro-scopy ( 31 P MRS) to characterize and differentiate malignant breast tumors, benign breast tumors and normal breast tissues in vivo. These studies were carried out following the methodical characterization of chemical extracts of malignant breast tumor, benign breast tumor and normal breast parenchymal surgical tissue specimens using high resolution 31 P MRS. Alterations in breast tissue metabolism, as a result of pathological processes, were postulated to be responsible for measurable differences between malignant breast tumors, benign breast tumors and normal breast tissues using magnetic resonance techniques. (author). 365 refs.; 37 figs.; 25 tabs

Magnetic resonance of phase transitions

CERN Document Server

Owens, Frank J; Farach, Horacio A

1979-01-01

Magnetic Resonance of Phase Transitions shows how the effects of phase transitions are manifested in the magnetic resonance data. The book discusses the basic concepts of structural phase and magnetic resonance; various types of magnetic resonances and their underlying principles; and the radiofrequency methods of nuclear magnetic resonance. The text also describes quadrupole methods; the microwave technique of electron spin resonance; and the Mössbauer effect. Phase transitions in various systems such as fluids, liquid crystals, and crystals, including paramagnets and ferroelectrics, are also

Magnetic Resonance Imaging Findings Predict the Recurrence of Chronic Subdural Hematoma

Science.gov (United States)

GOTO, Haruo; ISHIKAWA, Osamu; NOMURA, Masashi; TANAKA, Kentaro; NOMURA, Seiji; MAEDA, Keiichiro

2015-01-01

The exact predictive factors for postoperative recurrence of chronic subdural hematoma (CSDH) are still unknown. Based on the preoperative magnetic resonance imaging (MRI), low recurrence rate of T1-hyperintensity hematoma was previously reported. We investigated the other types of radiological findings which are related to the recurrence rate of CSDH in large number of patients analyzed by multivariate logistic regression model. Preoperative MRI and postoperative computed tomography (CT) were performed and the influence of the preoperative use of antiplatelet or anticoagulant drugs was also studied. The overall recurrence rate was 9.3% (47 of 505 hematomas). The MRI T1-iso/hypointensity group showed a significantly higher recurrence rate (18.2%, 29 of 159) compared to the other groups (5.2%, 18 of 346; p hematoma, antiplatelet or anticoagulant drug usage, residual hematoma on postoperative CT, and MRI classification (p hematoma and antiplatelet or anticoagulant drug usage did not increase the recurrence risk. The preoperative MRI findings, especially T1WI findings, have predictive value for postoperative recurrence of CSDH and the T1-iso/hypointensity group can be assumed to be a high recurrence risk group. PMID:25746312

Spectrum of fluorodeoxyglucose-positron emission tomography/computed tomography and magnetic resonance imaging findings of ovarian tumors.

Science.gov (United States)

Kitajima, Kazuhiro; Ueno, Yoshiko; Maeda, Tetsuo; Murakami, Koji; Kaji, Yasushi; Kita, Masato; Suzuki, Kayo; Sugimura, Kazuro

2011-11-01

The purpose of this article is to review fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) and magnetic resonance imaging (MRI) findings in a variety of benign, malignant, and borderline malignant ovarian tumors. It is advantageous to become familiar with the wide variety of FDG-PET/CT findings of this entity. Benign ovarian tumors generally have faint uptake, whereas endometriomas, fibromas, and teratomas show mild to moderate uptake. Malignant ovarian tumors generally have intense uptake, whereas tumors with a small solid component often show minimal uptake.

Intracranial meningiomas: magnetic resonance imaging findings in 78 cases

International Nuclear Information System (INIS)

Gasparetto, Emerson L.; Leite, Claudia da Costa; Lucato, Leandro T.; Barros, Cristiano Ventorin de; Marie, Sueli K.N.; Santana, Pedro; Aguiar, Paulo Henrique Pires de; Rosemberg, Sergio

2007-01-01

Objective: To present the magnetic resonance (MR) imaging findings of 78 patients with meningiomas diagnosed in a single institution. Method: 78 patients with histological proven intracranial meningioma were studied. There were 52 female and 26 male patients (median=56 years). All MR imaging examinations were performed with 1.5-T MR imaging unit with standard protocol. The images were studied by two neuroradiologists, who reached the decisions regarding the findings by consensus. Results: Most of the tumors showed low signal on T1- (60%) and high signal on T2- (68%) and FLAIR (69%) weighted images. Also, the lesions showed heterogeneous signal on T1 (60%), T2 (68%) and FLAIR (64%) sequences. After contrast administration, 83% (n=65) of the tumors presented accentuated and 17% (n=13) showed moderate enhancement. The tumors were located in the frontal lobe in 44% of the cases, in the parietal lobe in 35%, the occipital lobe in 19% and the temporal lobe in 12% of the patients. Areas of vasogenic edema around the tumors were seen in 90% of the cases. Twenty six per cent of the cases showed bone infiltration, and the dural tail sign was seen in 59% of the tumors. Conclusion: Intracranial meningiomas usually show heterogeneous low signal on T1- and high signal on T2-weighted and FLAIR images, with intense enhancement after contrast administration. The frontal and parietal lobes are commonly affected. In addition, brain edema, dural tail sign and bone infiltration are the most frequent associated findings. (author)

Migraine and magnetic resonance spectroscopy

DEFF Research Database (Denmark)

Younis, Samaira; Hougaard, Anders; Vestergaard, Mark B.

2017-01-01

Purpose of review: To present an updated and streamlined overview of the metabolic and biochemical aspect of the migraine pathophysiology based on findings from phosphorous (31P) and hydrogen (1H) magnetic resonance spectroscopy (MRS) studies. Recent findings: Despite of the variation in the meth......Purpose of review: To present an updated and streamlined overview of the metabolic and biochemical aspect of the migraine pathophysiology based on findings from phosphorous (31P) and hydrogen (1H) magnetic resonance spectroscopy (MRS) studies. Recent findings: Despite of the variation...... in the methodology and quality of the MRS migraine studies over time, some results were consistent and reproducible. 31P-MRS studies suggested reduced availability of neuronal energy and implied a mitochondrial dysfunction in the migraine brain. 1H-MRS studies reported interictal abnormalities in the excitatory...... and inhibitory neurotransmitters, glutamate and g-aminobutyric acid (GABA), suggesting persistent altered excitability in migraine patients. N-Acetylaspartate levels were decreased in migraine, probably due to a mitochondrial dysfunction and abnormal energy metabolism. The reported abnormalities may increase...

Magnetic resonance imaging

International Nuclear Information System (INIS)

Anon.

1988-01-01

Magnetic resonance imaging (MRI) is a new and innovative technique that affords anatomic images in multiple planes and that may provide information about tissue characterization. The magnetic resonance images are obtained by placing the patient or the area of interest within a powerful, highly uniform, static magnetic field. Magnetized protons (hydrogen nuclei) within the patient align like small magnets in this field. Radiofrequency pulses are then used to create an oscillating magnetic field perpendicular to the main field. Magnetic resonance images differ from those produced by x-rays: the latter are associated with absorption of x-ray energy while magnetic resonance images are based on proton density and proton relaxation dynamics. Proton characteristics vary according to the tissue under examination and reflect its physical and chemical properties. To resolve issues regarding safety and efficacy, the Warren Grant Magnuson Clinical Center and the Office of Medical Applications of Research of the National Institutes of Health (NIH) convened a consensus conference about MRI Oct 26 through 28, 1987. At the NIH, the Consensus Development Conference brings together investigators in the biomedical sciences, clinical investigators, practicing physicians, and consumer and special interest groups to make a scientific assessment of technologies, including drugs, devices, and procedures, and to seek agreement on their safety and effectiveness

Bronchobiliary fistula after hemihepatectomy: cholangiopancreaticography, computed tomography and magnetic resonance cholangiography findings

International Nuclear Information System (INIS)

Oettl, C.; Schima, W.; Metz-Schimmerl, S.; Fuegger, R.; Mayrhofer, T.; Herold, C.J.

1999-01-01

A bronchobiliary fistula (BBF), which is defined by an abnormal communication between the biliary system and the bronchial tree, is an uncommon complication after hemihepatectomy, trauma, hydatid disease, choledocholithiasis and other causes of biliary obstruction. We report the case of a 56-year-old man with colon cancer, who developed a BBF 2 months after right hemihepatectomy for liver metastases. The findings at endoscopic retrograde cholangiopancreaticography (ERCP), computed tomography (CT) and magnetic resonance cholangiography (MRC) included a stricture of the common bile duct and biliary leakage from the liver resection plane with biliary infiltration of the right lower lobe of the lung. The patient was treated successfully by endoscopic insertion of a biliary plastic stent which bridged the stricture and lead to closure of the fistula

Magnetic resonance imaging findings in patients presenting with (sub)acute cerebellar ataxia

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Schneider, Tanja [University Medical Center Hamburg-Eppendorf, Department of Diagnostic and Interventional Neuroradiology, Hamburg (Germany); The Johns Hopkins Hospital School of Medicine, Russell H. Morgan Department of Radiology and Radiological Sciences, Division of Neuroradiology, Baltimore, MD (United States); Thomalla, Goetz [University Medical Center Hamburg-Eppendorf, Department of Neurology, Hamburg (Germany); Goebell, Einar [University Medical Center Hamburg-Eppendorf, Department of Diagnostic and Interventional Neuroradiology, Hamburg (Germany); Piotrowski, Anna [The Johns Hopkins University School of Medicine, Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD (United States); Yousem, David Mark [The Johns Hopkins Hospital School of Medicine, Russell H. Morgan Department of Radiology and Radiological Sciences, Division of Neuroradiology, Baltimore, MD (United States)

2015-02-17

Acute or subacute cerebellar inflammation is mainly caused by postinfectious, toxic, neoplastic, vascular, or idiopathic processes and can result in cerebellar ataxia. Previous magnetic resonance (MR) studies in single patients who developed acute or subacute ataxia showed varying imaging features. Eighteen patients presenting with acute and subacute onset of ataxia were included in this study. Cases of chronic-progressive/hereditary and noncerebellar causes (ischemia, multiple sclerosis lesions, metastasis, bleedings) were excluded. MR imaging findings were then matched with the clinical history of the patient. An underlying etiology for ataxic symptoms were found in 14/18 patients (postinfectious/infectious, paraneoplastic, autoimmune, drug-induced). In two of five patients without MR imaging findings and three of eight patients with minimal imaging features (cerebellar atrophy, slight signal alterations, and small areas of restricted diffusion), adverse clinical outcomes were documented. Of the five patients with prominent MR findings (cerebellar swelling, contrast enhancement, or broad signal abnormalities), two were lost to follow-up and two showed long-term sequelae. No correlation was found between the presence of initial MRI findings in subacute or acute ataxia patients and their long-term clinical outcome. MR imaging was more flagrantly positive in cases due to encephalitis. (orig.)

Magnetic resonance imaging findings in patients presenting with (sub)acute cerebellar ataxia.

Science.gov (United States)

Schneider, Tanja; Thomalla, Götz; Goebell, Einar; Piotrowski, Anna; Yousem, David Mark

2015-06-01

Acute or subacute cerebellar inflammation is mainly caused by postinfectious, toxic, neoplastic, vascular, or idiopathic processes and can result in cerebellar ataxia. Previous magnetic resonance (MR) studies in single patients who developed acute or subacute ataxia showed varying imaging features. Eighteen patients presenting with acute and subacute onset of ataxia were included in this study. Cases of chronic-progressive/hereditary and noncerebellar causes (ischemia, multiple sclerosis lesions, metastasis, bleedings) were excluded. MR imaging findings were then matched with the clinical history of the patient. An underlying etiology for ataxic symptoms were found in 14/18 patients (postinfectious/infectious, paraneoplastic, autoimmune, drug-induced). In two of five patients without MR imaging findings and three of eight patients with minimal imaging features (cerebellar atrophy, slight signal alterations, and small areas of restricted diffusion), adverse clinical outcomes were documented. Of the five patients with prominent MR findings (cerebellar swelling, contrast enhancement, or broad signal abnormalities), two were lost to follow-up and two showed long-term sequelae. No correlation was found between the presence of initial MRI findings in subacute or acute ataxia patients and their long-term clinical outcome. MR imaging was more flagrantly positive in cases due to encephalitis.

Magnetic Resonance Imaging of Surgical Implants Made from Weak Magnetic Materials

Science.gov (United States)

Gogola, D.; Krafčík, A.; Štrbák, O.; Frollo, I.

2013-08-01

Materials with high magnetic susceptibility cause local inhomogeneities in the main field of the magnetic resonance (MR) tomograph. These inhomogeneities lead to loss of phase coherence, and thus to a rapid loss of signal in the image. In our research we investigated inhomogeneous field of magnetic implants such as magnetic fibers, designed for inner suture during surgery. The magnetic field inhomogeneities were studied at low magnetic planar phantom, which was made from four thin strips of magnetic tape, arranged grid-wise. We optimized the properties of imaging sequences with the aim to find the best setup for magnetic fiber visualization. These fibers can be potentially exploited in surgery for internal stitches. Stitches can be visualized by the magnetic resonance imaging (MRI) method after surgery. This study shows that the imaging of magnetic implants is possible by using the low field MRI systems, without the use of complicated post processing techniques (e.g., IDEAL).

Comparison between magnetic resonance findings and conventional techniques (ultrasonography and mammography) in breast disease

International Nuclear Information System (INIS)

Martin, J.L.; Garofono, J.M.; Berquet, A.; Fernandez, F.J.; Fuentes, P.; Alvarez de Cienfuegos, E.

1996-01-01

Although mammography is indisputably the best diagnostic method for detecting breast abnormalities, there are other techniques, such as ultrasonography and magnetic resonance, which are increasingly widely employed as additional indispensable aids. The present work compares mammography, ultrasound and magnetic resonance images of normal breast and of the major pathologies that can be observed in breast, including sclerosing adenosis, giant fibroadenoma, multifocal carcinoma, fibrocystic breast disease, infiltrating duct carcinoma, colloid carcinoma, radical scar, abscess and breast prosthesis. (Author) 10 refs

Soft-tissue perineurioma of the retroperitoneum in a 63-year-old man, computed tomography and magnetic resonance imaging findings: a case report

Directory of Open Access Journals (Sweden)

Yasumoto Mayumi

2010-08-01

Full Text Available Abstract Introduction Soft-tissue perineuriomas are rare benign peripheral nerve sheath tumors in the subcutis of the extremities and the trunks of young patients. To our knowledge, this the first presentation of the computed tomography and magnetic resonance imaging of a soft-tissue perineurioma in the retroperitoneum with pathologic correlation. Case presentation A 63-year-old Japanese man was referred for assessment of high blood pressure. Abdominal computed tomography and magnetic resonance imaging showed a well-defined, gradually enhancing tumor without focal degeneration or hemorrhage adjacent to the pancreatic body. Tumor excision with distal pancreatectomy and splenectomy was performed, as a malignant tumor of pancreatic origin could not be ruled out. No recurrence has been noted in the 16 months since the operation. Pathologic examination of the tumor revealed a soft-tissue perineurioma of the retroperitoneum. Conclusion Although the definitive diagnosis of soft-tissue perineurioma requires biopsy and immunohistochemical reactivity evaluation, the computed tomography and magnetic resonance imaging findings described in this report suggest inclusion of this rare tumor in the differential diagnosis when such findings occur in the retroperitoneum.

Pediatric magnetic resonance imaging

International Nuclear Information System (INIS)

Cohen, M.D.

1986-01-01

This book defines the current clinical potential of magnetic resonance imaging and focuses on direct clinical work with pediatric patients. A section dealing with the physics of magnetic resonance imaging provides an introduction to enable clinicians to utilize the machine and interpret the images. Magnetic resonance imaging is presented as an appropriate imaging modality for pediatric patients utilizing no radiation

Retroperitoneal and pelvic plexiform neurofibromatosis: computed tomography and magnetic resonance findings - case report and review of literature

International Nuclear Information System (INIS)

Cancado, Daniel Dutra; Bahia, Paulo Roberto Valle; Leijoto, Camila Cruz; Carvalho, Carlos Eduardo Souza

2005-01-01

The authors report a case of neurofibromatosis type I, characterized by multiple plexiform neurofibromas in the retroperitoneum and pelvis. Computed tomography showed markedly hypodense lesions involving mainly the psoas and the paravertebral regions, findings which could mimic other diseases such as abscesses and lymphadenopathy. Magnetic resonance imaging was useful to better evaluate the extension and internal structure of the neurofibromas. (author)

Advances in magnetic resonance 10

CERN Document Server

Waugh, John S

2013-01-01

Advances in Magnetic Resonance, Volume 10, presents a variety of contributions to the theory and practice of magnetic resonance. The book contains three chapters that examine superoperators in magnetic resonance; ultrasonically modulated paramagnetic resonance; and the utility of electron paramagnetic resonance (EPR) and electron-nuclear double-resonance (ENDOR) techniques for studying low-frequency modes of atomic fluctuations and their significance for understanding the mechanism of structural phase transitions in solids.

Least Squares Magnetic-Field Optimization for Portable Nuclear Magnetic Resonance Magnet Design

International Nuclear Information System (INIS)

Paulsen, Jeffrey L; Franck, John; Demas, Vasiliki; Bouchard, Louis-S.

2008-01-01

Single-sided and mobile nuclear magnetic resonance (NMR) sensors have the advantages of portability, low cost, and low power consumption compared to conventional high-field NMR and magnetic resonance imaging (MRI) systems. We present fast, flexible, and easy-to-implement target field algorithms for mobile NMR and MRI magnet design. The optimization finds a global optimum in a cost function that minimizes the error in the target magnetic field in the sense of least squares. When the technique is tested on a ring array of permanent-magnet elements, the solution matches the classical dipole Halbach solution. For a single-sided handheld NMR sensor, the algorithm yields a 640 G field homogeneous to 16,100 ppm across a 1.9 cc volume located 1.5 cm above the top of the magnets and homogeneous to 32,200 ppm over a 7.6 cc volume. This regime is adequate for MRI applications. We demonstrate that the homogeneous region can be continuously moved away from the sensor by rotating magnet rod elements, opening the way for NMR sensors with adjustable 'sensitive volumes'

Incidental enchondromas at knee magnetic resonance imaging: intraobserver and interobserver agreement and prevalence of imaging findings

Directory of Open Access Journals (Sweden)

Sandra Akemi Nakamura

2013-06-01

Full Text Available Objective To evaluate intra- and interobserver agreement in the identification of incidental enchondromas at knee magnetic resonance imaging, and to assess the prevalence of imaging findings. Materials and Methods Retrospective study reviewing 326 knee magnetic resonance images acquired in the period between November 2009 and September 2010. The images were independently and blindly analyzed by two specialists in musculoskeletal radiology, with the objective of identifying incidental enchondromas, presence of foci with signal similar to bone marrow and foci of signal absence suggestive of calcifications within the enchondromas. Inter- and intraobserver agreements were analyzed. Results Eleven lesions compatible with enchondromas (3.3% were identified. The interobserver agreement for the presence of enchondroma was high. Prevalence of foci of bone marrow signal inside the enchondromas was of 54.55%, and foci suggestive of calcification corresponded to 36.36%. The intraobserver agreement for foci of bone marrow signal in enchondromas was perfect, and interobserver agreement was high. Conclusion The prevalence of incidental enchondromas in the current study was compatible with data in the literature. Excellent agreement was observed in the identification of enchondromas and in the assessment of imaging findings. A higher prevalence of fat signal foci was observed as compared with signal absence suggestive of calcifications.

Magnetic resonance imaging findings associated with surgically proven rotator interval lesions

Energy Technology Data Exchange (ETDEWEB)

Vinson, Emily N.; Major, Nancy M. [Duke University Medical Center, Department of Radiology, P.O. Box 3808, Durham, NC (United States); Higgins, Laurence D. [Brigham and Women' s Hospital, Department of Orthopedic Surgery, Boston, MA (United States)

2007-05-15

To identify shoulder magnetic resonance imaging (MRI) findings associated with surgically proven rotator interval abnormalities. The preoperative MRI examinations of five patients with surgically proven rotator interval (RI) lesions requiring closure were retrospectively evaluated by three musculoskeletal-trained radiologists in consensus. We assessed the structures in the RI, including the coracohumeral ligament, superior glenohumeral ligament, fat tissue, biceps tendon, and capsule for variations in size and signal alteration. In addition, we noted associated findings of rotator cuff and labral pathology. Three of three of the MR arthrogram studies demonstrated extension of gadolinium to the cortex of the undersurface of the coracoid process compared with the control images, seen best on the sagittal oblique images. Four of five of the studies demonstrated subjective thickening of the coracohumeral ligament, and three of five of the studies demonstrated subjective thickening of the superior glenohumeral ligament. Five of five of the studies demonstrated a labral tear. The MRI arthrogram finding of gadolinium extending to the cortex of the undersurface of the coracoid process was noted on the studies of those patients with rotator interval lesions at surgery in this series. Noting this finding - especially in the presence of a labral tear and/or thickening of the coracohumeral ligament or superior glenohumeral ligament - may be helpful in the preoperative diagnosis of rotator interval lesions. (orig.)

Disc pathology after whiplash injury. A prospective magnetic resonance imaging and clinical investigation.

Science.gov (United States)

Pettersson, K; Hildingsson, C; Toolanen, G; Fagerlund, M; Björnebrink, J

1997-02-01

This study was used to evaluate the relationship between magnetic resonance imaging findings and clinical findings after whiplash injury. To identify initial soft-tissue damage after whiplash injury, the development of disc pathology, and the relationship of disc pathology to clinical findings. Although a few studies have reported pathological magnetic resonance imaging findings after whiplash injuries, there is no prospective study published to our knowledge. Thirty-nine patients, 20 women and 19 men with a mean age of 32 years, were treated for whiplash injury. Magnetic resonance imaging and clinical examination were performed in a blinded manner at a mean of 11 days after trauma. The procedure was repeated at a 2-year follow-up visit. Two patients could not be examined with the second magnetic resonance imaging because of claustrophobia and pregnancy, respectively. The authors found 13 patients (33%) with disc herniations with medullary (six cases) or dura (seven cases) impingement over the 2-year follow-up period. At the follow-up examination all patients with medullary impingement had persistent or increased symptoms, and three of 27 patients (11%) with no or slight changes on magnetic resonance imaging had persistent symptoms. No ligament injuries were diagnosed. Although disc pathology seems to be one contributing factor in the development of chronic symptoms after whiplash injury, it may be unnecessary to examine these patients in the acute phase with magnetic resonance imaging; correlating initial symptoms and signs to magnetic resonance imaging findings is difficult because of the relatively high proportion of false-positive results. Magnetic resonance imaging is indicated later in the course of treatment in patients with persistent arm pain, neurologic deficits or clinical signs of nerve root compression to diagnose disc herniations requiring surgery.

Children's (Pediatric) Magnetic Resonance Imaging

Science.gov (United States)

... Physician Resources Professions Site Index A-Z Children’s (Pediatric) Magnetic Resonance Imaging Children’s magnetic resonance imaging (MRI) ... limitations of Children’s (Pediatric) MRI? What is Children’s (Pediatric) MRI? Magnetic resonance imaging (MRI) is a noninvasive ...

Magnetic resonance imaging in spondyloarthritis--how to quantify findings and measure response

DEFF Research Database (Denmark)

Østergaard, Mikkel; Poggenborg, René Panduro; Axelsen, Mette Bjørndal

2010-01-01

Sensitive and reliable tools for monitoring disease activity and damage, and for prognostication, are essential in the management of patients with spondyloarthritis, including ankylosing spondylitis and psoriatic arthritis. Magnetic resonance imaging (MRI) allows direct visualisation...

Computed tomography and magnetic resonance imaging findings of solitary fibrous tumors in the pelvis: Correlation with histopathological findings

International Nuclear Information System (INIS)

Zhang Weidong; Chen Jianyu; Cao Yun; Liu Qingyu; Luo Rongguang

2011-01-01

Objective: We aimed to analyze the computed tomography (CT) and magnetic resonance imaging (MRI) findings of pelvic solitary fibrous tumors (SFTs) and to improve the diagnostic efficacy for such tumors. Methods: Six cases of pelvic SFTs confirmed by histopathology were analyzed retrospectively. Of the 6 patients, 4 had undergone CT scanning, and 2 had undergone magnetic resonance imaging. All the patients had undergone unenhanced and contrast-enhanced examinations, and 2 had also undergone dynamic CT enhancement examination. Image characteristics such as shape, size, number, edge, attenuation or intensity for each lesion before and after contrast enhancement were analyzed and compared with the pathomorphology of the tumors. Results: All the 6 cases showed oval or rounded and well-defined masses. Unenhanced CT images showed heterogeneous masses with patchy, necrotic foci in 3 cases and homogeneous mass in 1 case. None of the tumors showed calcification. Contrast-enhanced CT images showed marked, heterogeneous enhancement in the first and second cases. Dynamic enhancement scan demonstrated mild homogeneous enhancement in the third case and mild prolonged, delayed enhancement and washout in the fourth case. T1-weighted MR images showed heterogeneous mild hypointense lesion with linear hyperintensity in 1 case, and homogeneous isointensity in the other. T2-weighted images showed heterogeneous mixed intensity in 1 case and mostly hyperintensive lesion with hypointense foci in another case. A case showed marked heterogeneous enhancement and another showed marked homogeneous enhancement on contrast-enhanced T1-weighted images. Conclusion: Radiological findings of pelvic SFTs are variable and nonspecific. However, a well-defined, ovoid or rounded mass with hypointense on MR T2-weighted images and variable enhancement on CT and MR images may suggest the diagnosis of SFTs. Pelvic SFTs should be included in the differential diagnosis of regional tumors.

Sublingual epidermoid cyst presenting with distinctive magnetic resonance imaging findings.

Science.gov (United States)

Yoshida, Naohiro; Kodama, Kozue; Iino, Yukiko

2014-06-18

A case of sublingual epidermoid cyst presenting distinctive magnetic resonance imaging (MRI) findings is described. A 39-year-old man presented to our hospital with a three months progressive left submandibular swelling, difficulty moving his tongue, and snoring. Preoperative evaluation with MRI and fine needle aspiration cytology (FNAC) revealed that the heterogeneous cystic lesion contained the squamous cells, which is compatible with ectodermal tissue. The mass was located above the mylohyoid muscle and spread to the pharyngeal space. By considering the size, infection history, patient age, and location, the cyst was completely resected under general anesthesia via cervical approach without any complication. Histopathologically, the cyst wall was lined by stratified squamous epithelium with no skin appendage, suggesting an epidermoid cyst. Ultrasound (US), MRI and FNAC were very useful of the preoperative diagnosis for oral and sublingual lesion. The postoperative course was uneventful and without recurrence after 24 months. This case showed that epidermoid cysts formed the rarely heterogeneous cystic tumor and it underlined usefulness of preoperative diagnosis, such as US, MRI and FNAC for oral and sublingual tumor.

Magnetic Resonance Imaging (MRI) -- Head

Science.gov (United States)

... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging (MRI) of the head uses a powerful ... the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is a noninvasive medical test that ...

Children's (Pediatric) Magnetic Resonance Imaging

Medline Plus

Full Text Available ... Physician Resources Professions Site Index A-Z Children’s (Pediatric) Magnetic Resonance Imaging Children’s magnetic resonance imaging (MRI) ... limitations of Children’s (Pediatric) MRI? What is Children’s (Pediatric) MRI? Magnetic resonance imaging (MRI) is a noninvasive ...

Children's (Pediatric) Magnetic Resonance Imaging

Medline Plus

Full Text Available ... News Physician Resources Professions Site Index A-Z Children’s (Pediatric) Magnetic Resonance Imaging Children’s magnetic resonance imaging ( ... the limitations of Children’s (Pediatric) MRI? What is Children’s (Pediatric) MRI? Magnetic resonance imaging (MRI) is a ...

Magnetic resonance angiography (MRA)

International Nuclear Information System (INIS)

Arlart, I.P.; Guhl, L.

1992-01-01

An account is given in this paper of the physical and technical principles underlying the 'time-of-flight' technique for imaging of vessels by magnetic resonance tomography. Major indications for the new procedure of magnetic resonance angiography at present are intracerebral and extracerebral vessels, with digital subtraction angiography quite often being required to cope with minor alterations (small aneurysms, small occlusions). Magnetic resonance angiography and digital subtraction angiography are compared to each other for advantages and disadvantages. Basically, replacement of radiological angiography by magnetic resonance angiography appears to be possible only within limits, since X-ray diagnostics primarily provides morphological information about vessels, whereas flow dynamics is visualized by the 'time-of-flight' technique. (orig.) [de

The diagnosis of silicone breast-implant rupture: clinical findings compared with findings at magnetic resonance imaging

DEFF Research Database (Denmark)

Hölmich, Lisbet Rosenkrantz; Fryzek, Jon P; Kjøller, Kim

2005-01-01

The objective was to evaluate the usefulness of clinical examination in the evaluation of breast-implant integrity, using the diagnosis at magnetic resonance imaging (MRI) as the "gold standard." Fifty-five women with 109 implants underwent a breast examination either just before or shortly after...

Relationship between clinical findings of temporomandibular disorders and magnetic resonance imaging

International Nuclear Information System (INIS)

Iizuka, Yasuyuki; Miura, Hiroyuki; Ishikawa, Fujiro; Kikuchi, Shiori; Konishi, Nobuhiro; Sakamaki, Kimio

1996-01-01

The present study was conducted to investigate the relationship between magnetic resonance imaging (MRI) of the temporomandibular joint (TMJ) and clinical findings of patients having symptoms of temporomandibular disorders, and to consider the possibility to grasp the internal derangement of the TMJ from clinical findings. Subjects were 80 patients who visited to ask orthodontic treatment 16 males and 64 females. The average age was 22 years and 4 months. We performed a investigation of both their previous and present illness. In addition, to decide the correct condition concerning the internal derangement of the TMJ, patients were given MRI examinations (G. E. medical system Signa 1.5 Tesla) before orthodontic treatment. Results were as follows: The three symptoms of temporomandibular disorders-noise, pain, and abnormal mandibular movement, were not related to constant disk displacement. It seemed difficult to infer and obtain the diagnosis of the condition of internal derangement of the TMJ only from clinical findings. In a dental clinics having no medical imaging instrument such as MRI, it was, however, considered that the following items will make it possible to define the condition of internal derangements of the TMJ from clinical findings. As to respects concerning clinical findings, it is necessary to consider the previous illness as well as present illness. TMJ noise indicates a higher relationship to the disk displacement in MRI findings. The temporomandibular joint with plural symptoms indicated a higher incidence of disk displacement examined by MR Imaging than that with a single symptom. (author)

Magnetic Resonance Imaging (MRI) -- Head

Medline Plus

Full Text Available ... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging (MRI) of the head uses a powerful ... the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is a noninvasive medical test that ...

Capsular contracture and possible implant rupture: is magnetic resonance imaging useful?

Science.gov (United States)

Paetau, Alyssa A; McLaughlin, Sarah A; McNeil, Rebecca B; Sternberg, Erez; TerKonda, Sarvam P; Waldorf, James C; Perdikis, Galen

2010-03-01

Currently, magnetic resonance imaging is considered the accepted standard to evaluate breast implant integrity. To evaluate its utility in diagnosing ruptured silicone implants in the setting of capsular contracture and to correlate the preoperative assessment of implant integrity with or without magnetic resonance imaging with operative findings, 319 capsulectomies (171 patients with capsular contractures) were retrospectively reviewed. Preoperative magnetic resonance imaging was done on 160 implants, whereas the remaining 159 were evaluated using only physical examination and/or mammography. Postoperative results were analyzed to determine the sensitivity, specificity, and accuracy of preoperative magnetic resonance imaging in comparison with clinical and/or mammography evaluation alone. Although occasionally valuable, overall, preoperative magnetic resonance imaging was no more accurate than clinical evaluation with or without mammography in predicting implant status: magnetic resonance imaging 124 of 160 (78 percent) and clinical 121 of 159 (76 percent; p = 0.77). In the setting of capsular contracture, physical examination with or without mammogram is as accurate as magnetic resonance imaging in determining implant integrity. Although magnetic resonance imaging is a sensitive diagnostic tool, in symptomatic patients with capsular contracture, it cannot be viewed as infallible.

Magnetic nanoparticles in magnetic resonance imaging and diagnostics.

Science.gov (United States)

Rümenapp, Christine; Gleich, Bernhard; Haase, Axel

2012-05-01

Magnetic nanoparticles are useful as contrast agents for magnetic resonance imaging (MRI). Paramagnetic contrast agents have been used for a long time, but more recently superparamagnetic iron oxide nanoparticles (SPIOs) have been discovered to influence MRI contrast as well. In contrast to paramagnetic contrast agents, SPIOs can be functionalized and size-tailored in order to adapt to various kinds of soft tissues. Although both types of contrast agents have a inducible magnetization, their mechanisms of influence on spin-spin and spin-lattice relaxation of protons are different. A special emphasis on the basic magnetism of nanoparticles and their structures as well as on the principle of nuclear magnetic resonance is made. Examples of different contrast-enhanced magnetic resonance images are given. The potential use of magnetic nanoparticles as diagnostic tracers is explored. Additionally, SPIOs can be used in diagnostic magnetic resonance, since the spin relaxation time of water protons differs, whether magnetic nanoparticles are bound to a target or not.

Magnetic resonance tomography for trauma of the cervical spine

International Nuclear Information System (INIS)

Meydam, K.; Sehlen, S.; Schlenkhoff, D.; Kiricuta, J.C.; Beyer, H.K.

1986-01-01

Twenty patients who had suffered spinal trauma were examined by magnetic resonance tomography. Fifteen patients with first degree trauma in Erdmann's classification showed no abnormality. Magnetic resonance tomography of the cervical spine appears to be a suitable method for investigating patients with whiplash injuries. It is indicated following severe flexion injuries with subluxations and neurological symptoms, since it is the only method that can demonstrate the spinal cord directly and completely and show the extent of cord compression. For patients with thoracic trauma and rapidly developing neurological symptoms, magnetic resonance tomography is ideal for showing post-traumatic syringomyelia. Magnetic resonance tomography following whiplash injuries is recommended if plain films of the cervical spine show any abnormalities, as well as for the investigation of acute or sub-acute neurological abnormalities. The various findings are discussed. (orig.) [de

Magnetic resonance tomography for trauma of the cervical spine

Energy Technology Data Exchange (ETDEWEB)

Meydam, K.; Sehlen, S.; Schlenkhoff, D.; Kiricuta, J.C.; Beyer, H.K.

1986-12-01

Twenty patients who had suffered spinal trauma were examined by magnetic resonance tomography. Fifteen patients with first degree trauma in Erdmann's classification showed no abnormality. Magnetic resonance tomography of the cervical spine appears to be a suitable method for investigating patients with whiplash injuries. It is indicated following severe flexion injuries with subluxations and neurological symptoms, since it is the only method that can demonstrate the spinal cord directly and completely and show the extent of cord compression. For patients with thoracic trauma and rapidly developing neurological symptoms, magnetic resonance tomography is ideal for showing post-traumatic syringomyelia. Magnetic resonance tomography following whiplash injuries is recommended if plain films of the cervical spine show any abnormalities, as well as for the investigation of acute or sub-acute neurological abnormalities. The various findings are discussed.

Normal perinatal and paediatric postmortem magnetic resonance imaging appearances

Energy Technology Data Exchange (ETDEWEB)

Arthurs, Owen J. [Department of Radiology, Great Ormond Street Hospital for Children NHS Foundation Trust, London (United Kingdom); UCL Institute of Child Health, London (United Kingdom); Barber, Joy L. [Department of Radiology, Great Ormond Street Hospital for Children NHS Foundation Trust, London (United Kingdom); Taylor, Andrew M. [Cardiorespiratory Division, Great Ormond Street Hospital for Children NHS Foundation Trust, London (United Kingdom); UCL Institute of Cardiovascular Science, Centre for Cardiovascular Imaging, London (United Kingdom); Sebire, Neil J. [UCL Institute of Child Health, London (United Kingdom); Department of Histopathology, Great Ormond Street Hospital for Children NHS Foundation Trust, London (United Kingdom)

2015-04-01

As postmortem imaging becomes more widely used following perinatal and paediatric deaths, the correct interpretation of images becomes imperative, particularly given the increased use of postmortem magnetic resonance imaging. Many pathological processes may have similar appearances in life and following death. A thorough knowledge of normal postmortem changes is therefore required within postmortem magnetic resonance imaging to ensure that these are not mistakenly interpreted as significant pathology. Similarly, some changes that are interpreted as pathological if they occur during life may be artefacts on postmortem magnetic resonance imaging that are of limited significance. This review serves to illustrate briefly those postmortem magnetic resonance imaging changes as part of the normal changes after death in fetuses and children, and highlight imaging findings that may confuse or mislead an observer to identifying pathology where none is present. (orig.)

Magnetic resonance fingerprinting.

Science.gov (United States)

Ma, Dan; Gulani, Vikas; Seiberlich, Nicole; Liu, Kecheng; Sunshine, Jeffrey L; Duerk, Jeffrey L; Griswold, Mark A

2013-03-14

Magnetic resonance is an exceptionally powerful and versatile measurement technique. The basic structure of a magnetic resonance experiment has remained largely unchanged for almost 50 years, being mainly restricted to the qualitative probing of only a limited set of the properties that can in principle be accessed by this technique. Here we introduce an approach to data acquisition, post-processing and visualization--which we term 'magnetic resonance fingerprinting' (MRF)--that permits the simultaneous non-invasive quantification of multiple important properties of a material or tissue. MRF thus provides an alternative way to quantitatively detect and analyse complex changes that can represent physical alterations of a substance or early indicators of disease. MRF can also be used to identify the presence of a specific target material or tissue, which will increase the sensitivity, specificity and speed of a magnetic resonance study, and potentially lead to new diagnostic testing methodologies. When paired with an appropriate pattern-recognition algorithm, MRF inherently suppresses measurement errors and can thus improve measurement accuracy.

Advances in magnetic resonance 6

CERN Document Server

Waugh, John S

2013-01-01

Advances in Magnetic Resonance, Volume 6 focuses on the theoretical and practical aspects of applying magnetic resonance methods to various problems in physical chemistry, emphasizing the different aspects of the exegesis of these problems. This book discusses the gas phase magnetic resonance of electronically excited molecules; techniques for observing excited electronic states; NMR studies in liquids at high pressure; and effect of pressure on self-diffusion in liquids. The nuclear magnetic resonance investigations of organic free radicals; measurement of proton coupling constants by NMR; an

Ovarian granulocytic sarcoma: a case report and magnetic resonance imaging findings

International Nuclear Information System (INIS)

Pereira, Licia Pacheco; Monte, Hipolito

2008-01-01

Granulocytic sarcoma (chloroma) is a tumor consisting of myeloid precursors in an extramedullary site. It is complication of both acute and chronic myelogenous leukemias. Although the lesion can occur at any site, ovarian involvement is rare. We report a case of ovary tumor associated with acute myeloid leukaemia and its imaging appearance on magnetic resonance. (author)

Magnetic resonance imaging findings of mumps meningoencephalitis with bilateral hippocampal lesions without preceding acute parotitis: A case report

Energy Technology Data Exchange (ETDEWEB)

Woo, Ah Reum; Lee, Ha Young; Lim, Myung Kwan; Kang, Young Hye; Cho, Soon Gu; Choi, Seong Hye; Baek, Ji Hyeon [Inha University School of Medicine, Incheon (Korea, Republic of)

2017-04-15

Meningitis is a common central nervous system (CNS) complication of the mumps, a viral infection, but encephalitis and meningoencephalitis are less common in mumps. We describe magnetic resonance imaging findings of acute mumps meningoencephalitis in a 32-year-old male who showed bilateral hippocampal lesions without preceding parotitis. Although it is rare, hippocampal involvement should be considered a CNS complication of mumps infection.

Finding the Truth in Medical Imaging: Painting the Picture of Appropriateness for Magnetic Resonance Imaging in Canada.

Science.gov (United States)

Vanderby, Sonia; Peña-Sánchez, Juan Nicolás; Kalra, Neil; Babyn, Paul

2015-11-01

Questions about the appropriateness of medical imaging exams, particularly related to magnetic resonance exams, have arisen in recent years. However, the prevalence of inappropriate imaging in Canada is unclear as inappropriate exam proportion estimates are often based on studies from other countries. Hence, we sought to compare and summarize Canadian studies related to magnetic resonance imaging appropriateness. We completed a systematic literature search identifying studies related to magnetic resonance appropriateness in Canada published between 2003 and 2013. Two researchers independently searched and evaluated the literature available. Articles that studied or discussed magnetic resonance appropriateness in Canada were selected based on titles, abstracts, and, where necessary, full article review. Articles relating solely to other modalities or countries were excluded, as were imaging appropriateness guidelines and reviews. Fourteen articles were included: 8 quantitative studies and 6 editorials/commentaries. The quantitative studies reported inappropriate proportions of magnetic resonance exams ranging from 2%-28.5%. Our review also revealed substantial variations among study methods and analyses. Common topics identified among editorials/commentaries included reasons for obtaining imaging in general and for selecting a specific modality, consequences of inappropriate imaging, factors contributing to demand, and suggested means of mitigating inappropriate medical imaging use. The available studies do not support the common claim that 30% of medical imaging exams in Canada are inappropriate. The actual proportion of inappropriate magnetic resonance exams has not yet been established conclusively in Canada. Further research, particularly on a widespread national scale, is needed to guide healthcare policies. Copyright © 2015 Canadian Association of Radiologists. Published by Elsevier Inc. All rights reserved.

Granular Cell Tumor of the Neurohypophysis: A Case Report with Magnetic Resonance and CT Imaging Findings

Energy Technology Data Exchange (ETDEWEB)

Choo, Ka Yeon; Lee, Sun Jin; Ahn, Kook Jin; Jung, So Lyung; Kim, Bum Soo [Dept. of Radiology, Seoul St.Mary' s Hospital, The Catholic University of Korea College of Medicine, Seoul (Korea, Republic of); Lee, Yeon Soo [Dept. of Pathology, Seoul St.Mary' s Hospital, The Catholic University of Korea College of Medicine, Seoul (Korea, Republic of); Jeun, Shin Soo [Dept. of Neurosurgery, Seoul St.Mary' s Hospital, The Catholic University of Korea College of Medicine, Seoul (Korea, Republic of)

2011-11-15

A granular cell tumor (GCT) usually occurs as a small, solitary, nodular tumor and is more prevalent in adult females. The authors report the magnetic resonance (MR) and CT imaging findings in a 61-year-old woman with GCT of the neurohypophysis presenting with a history of reduced visual acuity in her right eye. MR images showed a suprasellar mass with an isointense signal on a T1-weighted image and an hypointense signal on a T2-weighted image. The histopathological examination revealed a granular cell tumor. In this article, the MR and CT imaging findings of GCT of the neurohypophysis with the literature reviews are discussed.

Granular Cell Tumor of the Neurohypophysis: A Case Report with Magnetic Resonance and CT Imaging Findings

International Nuclear Information System (INIS)

Choo, Ka Yeon; Lee, Sun Jin; Ahn, Kook Jin; Jung, So Lyung; Kim, Bum Soo; Lee, Yeon Soo; Jeun, Shin Soo

2011-01-01

A granular cell tumor (GCT) usually occurs as a small, solitary, nodular tumor and is more prevalent in adult females. The authors report the magnetic resonance (MR) and CT imaging findings in a 61-year-old woman with GCT of the neurohypophysis presenting with a history of reduced visual acuity in her right eye. MR images showed a suprasellar mass with an isointense signal on a T1-weighted image and an hypointense signal on a T2-weighted image. The histopathological examination revealed a granular cell tumor. In this article, the MR and CT imaging findings of GCT of the neurohypophysis with the literature reviews are discussed.

Proton magnetic resonance spectroscopy and perfusion magnetic resonance imaging in the evaluation of musculoskeletal tumors

International Nuclear Information System (INIS)

Costa, Flavia Martins; Setti, Marcela; Vianna, Evandro Miguelote; Domingues, Romulo Cortes; Meohas, Walter; Rezende, Jose Francisco; Gasparetto, Emerson Leandro

2009-01-01

Objective: To assess the role of proton magnetic resonance spectroscopy and dynamic contrast-enhanced magnetic resonance imaging in the differentiation between malignant and benign musculoskeletal tumors. Materials And Methods: Fifty-five patients with musculoskeletal tumors (27 malignant and 28 benign) were studied. The examinations were performed in a 1.5 T magnetic resonance scanner with standard protocol, and single voxel proton magnetic resonance spectroscopy with 135 msec echo time. The dynamic contrast study was performed using T1-weighted gradient-echo sequence after intravenous gadolinium injection. Time signal intensity curves and slope values were calculated. The statistical analysis was performed with the Levene's test, followed by a Student's t-test, besides the Pearson's chi-squared and Fischer's exact tests. Results: Proton magnetic resonance spectroscopy sensitivity, specificity and accuracy were, respectively, 87.5%, 92.3% and 90.9% (p < 0.0001). Statistically significant difference was observed in the slope (%/min) between benign (mean, 27.5%/min) and malignant (mean, 110.9%/min) lesions (p < 0.0001). Conclusion: The time-intensity curve and slope values using dynamic-enhanced perfusion magnetic resonance imaging in association with the presence of choline peak demonstrated by single voxel magnetic resonance spectroscopy study are useful in the differentiation between malignant and benign musculoskeletal tumors. (author)

Relationship between higher cortical dysfunction and the findings of magnetic resonance imaging in systemic lupus erythematosus

Energy Technology Data Exchange (ETDEWEB)

Maeshima, Etsuko; Maeshima, Shinichiro; Yamada, Yoichi; Yukawa, Susumu [Wakayama Medical Coll. (Japan)

1996-04-01

The relationship between systemic lupus erythematosus (SLE) and organic lesions was investigated by magnetic resonance imaging (MRI) to clarify the etiology of higher cortical dysfunction in SLE. The subjects were 10 patients with SLE, and higher cortical dysfunction was observed in 8 (80%) of the 10 patients. Five (82.5%) of the 8 patients showed abnormal MRI findings. The findings of higher cortical dysfunction were consistent with the MRI findings in 1 of the 5 patients, but not in the remaining four. MRI revealed no lesion despite the presence of higher cortical dysfunction in three patients. These results suggest that the association of organic changes and functional changes in cerebral nerve cells is important for etiology of higher cortical dysfunction in SLE. (author).

Relationship between higher cortical dysfunction and the findings of magnetic resonance imaging in systemic lupus erythematosus

International Nuclear Information System (INIS)

Maeshima, Etsuko; Maeshima, Shinichiro; Yamada, Yoichi; Yukawa, Susumu

1996-01-01

The relationship between systemic lupus erythematosus (SLE) and organic lesions was investigated by magnetic resonance imaging (MRI) to clarify the etiology of higher cortical dysfunction in SLE. The subjects were 10 patients with SLE, and higher cortical dysfunction was observed in 8 (80%) of the 10 patients. Five (82.5%) of the 8 patients showed abnormal MRI findings. The findings of higher cortical dysfunction were consistent with the MRI findings in 1 of the 5 patients, but not in the remaining four. MRI revealed no lesion despite the presence of higher cortical dysfunction in three patients. These results suggest that the association of organic changes and functional changes in cerebral nerve cells is important for etiology of higher cortical dysfunction in SLE. (author)

Magnetic resonance appearance of monoclonal gammopathies of unknown significance and multiple myeloma. The GRI Study Group.

Science.gov (United States)

Bellaïche, L; Laredo, J D; Lioté, F; Koeger, A C; Hamze, B; Ziza, J M; Pertuiset, E; Bardin, T; Tubiana, J M

1997-11-01

A prospective multicenter study. To evaluate the use of magnetic resonance imaging, in the differentiation between monoclonal gammopathies of unknown significance and multiple myeloma. Although multiple myeloma has been studied extensively with magnetic resonance imaging, to the authors' knowledge, no study has evaluated the clinical interest of magnetic resonance imaging in the differentiation between monoclonal gammopathies of unknown significance and multiple myeloma. The magnetic resonance examinations of the thoracolumbar spine in 24 patients with newly diagnosed monoclonal gammopathies of unknown significance were compared with those performed in 44 patients with newly diagnosed nontreated multiple myeloma. All findings on magnetic resonance examination performed in patients with monoclonal gammopathies of unknown significance were normal, whereas findings on 38 (86%) of the 44 magnetic resonance examinations performed in patients with multiple myeloma were abnormal. Magnetic resonance imaging can be considered as an additional diagnostic tool in differentiating between monoclonal gammopathies of unknown significance and multiple myeloma, which may be helpful when routine criteria are not sufficient. An abnormal finding on magnetic resonance examination in a patient with monoclonal gammopathies of unknown significance should suggest the diagnosis of multiple myeloma after other causes of marrow signal abnormalities are excluded. Magnetic resonance imaging also may be proposed in the long-term follow-up of monoclonal gammopathies of unknown significance when a new biologic or clinical event suggests the diagnosis of malignant monoclonal gammopathy.

Intervertebral disc disease in dogs - Part 2: Comparison of clinical, magnetic resonance imaging, and histological findings in 74 surgically treated dogs

NARCIS (Netherlands)

Kranenburg, H.C.; Grinwis, G.C.M.; Bergknut, N.; Gahrmann, Ninke; Voorhout, G.; Hazewinkel, H.A.W.

The relationship between intervertebral disc (IVD) disease and IVD degeneration remains unclear. The aim of the present study was to compare the clinical severity of IVD herniation (IVDH), determined with a neurological grading system, with findings of magnetic resonance imaging (MRI) and

Magnetic Resonance Imaging Studies of Postpartum Depression: An Overview

Directory of Open Access Journals (Sweden)

Marco Fiorelli

2015-01-01

Full Text Available Postpartum depression is a frequent and disabling condition whose pathophysiology is still unclear. In recent years, the study of the neural correlates of mental disorders has been increasingly approached using magnetic resonance techniques. In this review we synthesize the results from studies on postpartum depression in the context of structural, functional, and spectroscopic magnetic resonance studies of major depression as a whole. Compared to the relative wealth of data available for major depression, magnetic resonance studies of postpartum depression are limited in number and design. A systematic literature search yielded only eleven studies conducted on about one hundred mothers with postpartum depression overall. Brain magnetic resonance findings in postpartum depression appear to replicate those obtained in major depression, with minor deviations that are not sufficient to delineate a distinct neurobiological profile for this condition, due to the small samples used and the lack of direct comparisons with subjects with major depression. However, it seems reasonable to expect that studies conducted in larger populations, and using a larger variety of brain magnetic resonance techniques than has been done so far, might allow for the identification of neuroimaging signatures for postpartum depression.

Enterovirus 71-related encephalomyelitis: usual and unusual magnetic resonance imaging findings

International Nuclear Information System (INIS)

Jang, Seonah; Suh, Sang-Il; Ha, Su Min; Seol, Hae-Young; Byeon, Jung Hye; Eun, Baik-Lin; Lee, Young Hen; Seo, Hyung Suk; Eun, So-Hee

2012-01-01

Most enterovirus (EV) 71 infections manifest as mild cases of hand-foot-mouth disease (HFMD)/herpangina with seasonal variations, having peak incidence during the summer. Meanwhile, EV 71 may involve the central nervous system (CNS), causing severe neurologic disease. In many cases, enteroviral encephalomyelitis involves the central midbrain, posterior portion of the medulla oblongata and pons, bilateral dentate nuclei of the cerebellum, and the ventral roots of the cervical spinal cord, and the lesions show hyperintensity on T2-weighted and fluid-attenuation inversion recovery (FLAIR) images. Our goal was to review usual and unusual magnetic resonance (MR) findings in CNS involvement of enteroviral infection. Among consecutive patients who had HFMD and clinically suspected encephalitis or myelitis and who underwent brain or spinal MR imaging, five patients revealed abnormal MR findings. Diffusion-weighted and conventional MR and follow-up MR images were obtained. From cerebrospinal fluid, stool, or nasopharyngeal swabs, EV 71 was confirmed in all patients. MR imaging studies of two patients showed hyperintensity in the posterior portion of the brainstem on T2-weighted and FLAIR images, which is the well-known MR finding of EV 71 encephalitis. The remaining three cases revealed unusual manifestations: leptomeningeal enhancement, abnormal enhancement along the ventral roots at the conus medullaris level without brain involvement, and hyperintensity in the left hippocampus on T2/FLAIR images. EV 71 encephalomyelitis shows relatively characteristic MR findings; therefore, imaging can be helpful in radiologic diagnosis. However, physicians should also be aware of unusual radiologic manifestations of EV 71. (orig.)

Enterovirus 71-related encephalomyelitis: usual and unusual magnetic resonance imaging findings

Energy Technology Data Exchange (ETDEWEB)

Jang, Seonah; Suh, Sang-Il; Ha, Su Min; Seol, Hae-Young [Korea University Guro Hospital, Korea University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Byeon, Jung Hye; Eun, Baik-Lin [Korea University Guro Hospital, Korea University College of Medicine, Department of Pediatrics, Seoul (Korea, Republic of); Lee, Young Hen; Seo, Hyung Suk [Korea University Ansan Hospital, Korea University College of Medicine, Department of Radiology, Ansan (Korea, Republic of); Eun, So-Hee [Korea University Ansan Hospital, Korea University College of Medicine, Department of Pediatrics, Ansan (Korea, Republic of)

2012-03-15

Most enterovirus (EV) 71 infections manifest as mild cases of hand-foot-mouth disease (HFMD)/herpangina with seasonal variations, having peak incidence during the summer. Meanwhile, EV 71 may involve the central nervous system (CNS), causing severe neurologic disease. In many cases, enteroviral encephalomyelitis involves the central midbrain, posterior portion of the medulla oblongata and pons, bilateral dentate nuclei of the cerebellum, and the ventral roots of the cervical spinal cord, and the lesions show hyperintensity on T2-weighted and fluid-attenuation inversion recovery (FLAIR) images. Our goal was to review usual and unusual magnetic resonance (MR) findings in CNS involvement of enteroviral infection. Among consecutive patients who had HFMD and clinically suspected encephalitis or myelitis and who underwent brain or spinal MR imaging, five patients revealed abnormal MR findings. Diffusion-weighted and conventional MR and follow-up MR images were obtained. From cerebrospinal fluid, stool, or nasopharyngeal swabs, EV 71 was confirmed in all patients. MR imaging studies of two patients showed hyperintensity in the posterior portion of the brainstem on T2-weighted and FLAIR images, which is the well-known MR finding of EV 71 encephalitis. The remaining three cases revealed unusual manifestations: leptomeningeal enhancement, abnormal enhancement along the ventral roots at the conus medullaris level without brain involvement, and hyperintensity in the left hippocampus on T2/FLAIR images. EV 71 encephalomyelitis shows relatively characteristic MR findings; therefore, imaging can be helpful in radiologic diagnosis. However, physicians should also be aware of unusual radiologic manifestations of EV 71. (orig.)

Diagnosis of a sigmoid volvulus in pregnancy: ultrasonography and magnetic resonance imaging findings.

Science.gov (United States)

Palmucci, Stefano; Lanza, Maria Letizia; Gulino, Fabrizio; Scilletta, Beniamino; Ettorre, Giovanni Carlo

2014-02-01

Sigmoid volvulus complicating pregnancy is a rare, non-obstetric cause of abdominal pain that requires prompt surgical intervention (decompression) to avoid intestinal ischemia and perforation. We report the case of a 31-week pregnant woman with abdominal pain and subsequent development of constipation. Preoperative diagnosis was achieved using magnetic resonance imaging and ultrasonography: the large bowel distension and a typical whirl sign - near a sigmoid colon transition point - suggested the diagnosis of sigmoid volvulus. The decision to refer the patient for emergency laparotomy was adopted without any ionizing radiation exposure, and the pre-operative diagnosis was confirmed after surgery. Imaging features of sigmoid volvulus and differential diagnosis from other non-obstetric abdominal emergencies in pregnancy are discussed in our report, with special emphasis on the diagnostic capabilities of ultrasonography and magnetic resonance imaging.

Normal and pathological findings for the facial nerve on magnetic resonance imaging

International Nuclear Information System (INIS)

Al-Noury, K.; Lotfy, A.

2011-01-01

Aim: To demonstrate the enhanced radiological anatomy and common pathological conditions of the facial nerve by using magnetic resonance imaging (MRI). Materials and methods: A retrospective review of the MRI findings of the facial nerve of 146 patients who visited a tertiary academic referral center was conducted. Results: The radiological anatomy of the facial nerve was well illustrated using MRI, as were most of the common pathological conditions of the facial nerve. Conclusions: Enhancement of the facial nerve in MRI should be correlated with the clinical data. Normal individuals can show enhancement of the tympanic or vertical segments of the facial nerve. Enhancement of the labyrinthine portion of the nerve is almost diagnostic of Bell's palsy. No specific enhancement patterns were observed for tumours or for infections of the middle or external ear. A larger population study is required for the accurate assessment of facial nerve enhancement in multiple sclerosis patients.

Magnetic resonance for wireless power transfer

OpenAIRE

Hui, SYR

2016-01-01

Magnetic resonance has been a cornerstone of nonradiative wireless power transfer (WPT) since the late 19th century. However, some researchers have the misconception that magnetic resonance for WPT was developed recently. This article traces some early work of Tesla and other researchers related to the use of magnetic resonance in WPT. Included are some examples of magnetic resonance-based WPT projects conducted by researchers in the biomedical and power electronics communities over the last ...

Cardiac magnetic resonance imaging

African Journals Online (AJOL)

2011-03-06

Mar 6, 2011 ... Cardiac magnetic resonance imaging. Cardiovascular magnetic resonance imaging is becoming a routine diagnostic technique. BRUCE s sPOTTiswOOdE, PhD. MRC/UCT Medical Imaging Research Unit, University of Cape Town, and Division of Radiology, Stellenbosch University. Bruce Spottiswoode ...

The role of magnetic resonance cholangiopancreatography and ...

African Journals Online (AJOL)

) is accepted as the gold standard, there is a place for magnetic resonance cholangiopancreatography (MRCP) and diffusion-weighted imaging (DWI) in the diagnosis of obstructive biliary disorders. Aim: To compare the findings of MRCP with ...

Advances in magnetic resonance 12

CERN Document Server

Waugh, John S

2013-01-01

Advances in Magnetic Resonance, Volume 12, presents a variety of contributions to the theory and practice of magnetic resonance. The book contains six chapters and begins with a discussion of diffusion and self-diffusion measurements by nuclear magnetic resonance. This is followed by separate chapters on spin-lattice relaxation time in hydrogen isotope mixtures; the principles of optical detection of nuclear spin alignment and nuclear quadropole resonance; and the spin-1 behavior, including the relaxation of the quasi-invariants of the motion of a system of pairs of dipolar coupled spin-1/2 nu

Infantile fibrosarcoma: Magnetic resonance imaging findings in six cases

Energy Technology Data Exchange (ETDEWEB)

Canale, Sandra [Department of Radiology, Institut Gustave-Roussy, 39 rue Camille Desmoulins, 94805 Villejuif (France)], E-mail: canalesandra@yahoo.com; Vanel, Daniel [Department of Radiology, Institut Gustave-Roussy, 39 rue Camille Desmoulins, 94805 Villejuif (France); Istituti Ortopedici Rizzoli, 1/10 via di Barbiano, 40136 Bologna (Italy); Couanet, Dominique [Department of Radiology, Institut Gustave-Roussy, 39 rue Camille Desmoulins, 94805 Villejuif (France); Patte, Catherine [Department of Pediatrics, Institut Gustave-Roussy, 39 rue Camille Desmoulins, 94805 Villejuif (France); Caramella, Caroline; Dromain, Clarisse [Department of Radiology, Institut Gustave-Roussy, 39 rue Camille Desmoulins, 94805 Villejuif (France)

2009-10-15

Purpose: To retrospectively review magnetic resonance (MR) imaging features in a series of six infantile fibrosarcomas to find out if MR can suggest this unusual diagnosis and to highlight the value of MR during and following treatment. Materials and methods: The records of six cases of histologically proven infantile fibrosarcoma were retrieved from the files of our cancer center. All imaging data available were consensually reviewed by two radiologists. Results: There were five females and one male (age range at diagnosis, 0-12 months; mean, 6 months). The most common finding was a well-circumscribed single mass in five patients (83%). All tumors had arisen on limbs; at their proximal or distal extremity or at the root of the limb. The masses were 9 cm large in mean diameter. The initial tumor signal was isointense to muscle on T1-weighted and hyperintense on T2-weighted sequences. All masses were well circumscribed and half of them contained internal fibrous septa. The internal signal was homogeneous in three patients and heterogeneous in the three others. An intense enhancement was seen in all three contrast-enhanced exams available; heterogeneous in two cases and homogeneous in one. Osseous erosion was observed in only one patient who was the only one with distant metastasis. After treatment (chemotherapy and very limited surgery), tumors had totally disappeared, leaving muscle fat infiltration in two patients and subcutaneous fat hypertrophy in one patient. Conclusion: Although imaging findings are not specific of infantile fibrosarcoma, this diagnosis could be suggested when MR imaging depicts a large well-circumscribed mass arising in a limb at birth or during the neonatal period. This mass is sometimes heterogeneous and septate and exhibits an isointense T1- and hyperintense T2-weighted signals and strong enhancement. MR is also the technique of choice for follow-up during treatment which consists nowadays almost exclusively in chemotherapy.

Magnetic Resonance Force Microscopy System

Data.gov (United States)

Federal Laboratory Consortium — The Magnetic Resonance Force Microscopy (MRFM) system, developed by ARL, is the world's most sensitive nuclear magnetic resonance (NMR) spectroscopic analysis tool,...

Magnetic resonance imaging

International Nuclear Information System (INIS)

Robertson, Angus

1990-01-01

An assessment is made of the clinical benefits of expensive diagnostic technology, such as the magnetic resonance imaging. It is concluded that to most radiologists, magnetic resonance imaging has a definite place in the diagnostic scenario, especially for demonstrating central nervous system lesions in multiple sclerosis. While it is recognized that medical and financial resources are limited, it is emphasised that the cost to society must be balanced against the patient benefit. 17 refs

Bayesian estimation of multicomponent relaxation parameters in magnetic resonance fingerprinting.

Science.gov (United States)

McGivney, Debra; Deshmane, Anagha; Jiang, Yun; Ma, Dan; Badve, Chaitra; Sloan, Andrew; Gulani, Vikas; Griswold, Mark

2018-07-01

To estimate multiple components within a single voxel in magnetic resonance fingerprinting when the number and types of tissues comprising the voxel are not known a priori. Multiple tissue components within a single voxel are potentially separable with magnetic resonance fingerprinting as a result of differences in signal evolutions of each component. The Bayesian framework for inverse problems provides a natural and flexible setting for solving this problem when the tissue composition per voxel is unknown. Assuming that only a few entries from the dictionary contribute to a mixed signal, sparsity-promoting priors can be placed upon the solution. An iterative algorithm is applied to compute the maximum a posteriori estimator of the posterior probability density to determine the magnetic resonance fingerprinting dictionary entries that contribute most significantly to mixed or pure voxels. Simulation results show that the algorithm is robust in finding the component tissues of mixed voxels. Preliminary in vivo data confirm this result, and show good agreement in voxels containing pure tissue. The Bayesian framework and algorithm shown provide accurate solutions for the partial-volume problem in magnetic resonance fingerprinting. The flexibility of the method will allow further study into different priors and hyperpriors that can be applied in the model. Magn Reson Med 80:159-170, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

Spontaneous intracranial hypotension syndrome: magnetic resonance findings in two patients

International Nuclear Information System (INIS)

Ortega, R.; Pastor, J.; Escamilla, F.; Romero, M. I.

1999-01-01

The postural headache syndrome associated with a decrease in the cerebrospinal fluid (CSF) pressure is generally secondary to the CSF leakage that usually occurs after diagnostic lumbar puncture. Spontaneous intracranial hypotension can not be attributed to any known cause or previous diagnostic or therapeutic intervention. The syndrome is characterized by severe headache that is relieved by lying supine. During lumbar puncture, the CSF pressure is normally low. We present two patients in whom gadolinium-enhanced magnetic resonance imaging showed widespread thickening and enhancement of the dura mater and subdural fluid collections. (Author) 13 refs

Advances in magnetic resonance 11

CERN Document Server

Waugh, John S

2013-01-01

Advances in Magnetic Resonance, Volume 11, presents a variety of contributions to the theory and practice of magnetic resonance. The book contains three chapters and begins with a discussion of the principles and applications of dynamic nuclear polarization, with emphasis on molecular motions and collisions, intermolecular couplings, and chemical interactions. Subsequent chapters focus on the assessment of a proposed broadband decoupling method and studies of time-domain (or Fourier transform) multiple-quantum nuclear magnetic resonance.

The role of magnetic resonance cholangiography in the evaluation of biliary anatomy in living liver donors

International Nuclear Information System (INIS)

Arruda, Elaine Cristina de Moraes; Coelho, Julio Cezar Uili; Matias, Jorge Eduardo Fouto

2008-01-01

Objective: The present study was aimed at evaluating the accuracy of magnetic resonance cholangiography in the assessment of the biliary anatomy in living liver donors in correlation with surgical findings. Materials And Methods: Fifty living liver donors were retrospectively evaluated at Hospital de Clinicas da Universidade Federal do Parana, Curitiba, PR, Brazil. Cholangiographic images were analyzed and results were compared with intraoperative findings. Only anatomical alterations that affected the surgical strategy and had not been previously observed at magnetic resonance cholangiography were considered as being in disagreement. Results: Anatomical variations were found in 7 donors at magnetic resonance cholangiography, and in 14 during surgery. Agreement between imaging and surgical findings was observed in 41 of the 50 patients, and disagreement in 9. Magnetic resonance cholangiography sensitivity, specificity, positive and negative predictive values, and accuracy were respectively 43%, 97%, 86%, 81% and 81.6%. Conclusion: Magnetic resonance imaging is a safe and non invasive method for preoperative evaluation of the biliary tract in living liver donors. However some anatomical abnormalities are not detected by magnetic resonance cholangiography. (author)

Magnetic resonance imaging: effects of magnetic field strength

International Nuclear Information System (INIS)

Crooks, L.E.; Arakawa, M.; Hoenninger, J.; McCarten, B.; Watts, J.; Kaufman, L.

1984-01-01

Magnetic resonance images of the head, abdomen, and pelvis of normal adult men were obtained using varying magnetic field strength, and measurements of T1 and T2 relaxations and of signal-to-noise (SN) ratios were determined. For any one spin echo sequence, gray/white matter contrast decreases and muscle/fat contrast increases with field. SN levels rise rapidly up to 3.0 kgauss and then change more slowly, actually dropping for muscle. The optimum field for magnetic resonance imaging depends on tissue type, body part, and imaging sequence, so that it does not have a unique value. Magnetic resonance systems that operate in the 3.0-5.0 kgauss range achieve most or all of the gains that can be achieved by higher magnetic fields

Sequential Magnetic Resonance Imaging Finding of Intramedullary Spinal Cord Abscess including Diffusion Weighted Image: a Case Report

Energy Technology Data Exchange (ETDEWEB)

Roh, Jae Eun; Lee, Seung Young; Cha, Sang Hoon; Cho, Bum Sang; Jeon, Min Hee; Kang, Min Ho [Chungbuk National University College of Medicine, Cheongju (Korea, Republic of)

2011-04-15

Intramedullary spinal cord abscess (ISCA) is a rare infection of the central nervous system. We describe the magnetic resonance imaging (MRI) findings, including the diffusion-weighted imaging (DWI) findings, of ISCA in a 78-year-old man. The initial conventional MRI of the thoracic spine demonstrated a subtle enhancing nodule accompanied by significant edema. On the follow-up MRI after seven days, the nodule appeared as a ring-enhancing nodule. The non-enhancing central portion of the nodule appeared hyperintense on DWI with a decreased apparent diffusion coefficient (ADC) value on the ADC map. We performed myelotomy and surgical drainage, and thick, yellowish pus was drained

Magnetic resonance imaging of knee osteonecrosis: a study of 19 cases

Energy Technology Data Exchange (ETDEWEB)

Cunha, Daniel Leme da; Ribeiro, Elisio Jose Salgado; Domingues, Romeu Cortes, E-mail: danielc@predialnet.com.b [Clinica de Diagnostico por Imagem (CDPI), Rio de Janeiro, RJ (Brazil); Pires Carvalho, Antonio Carlos [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Faculdade de Medicina

2010-04-15

Objective: to describe epidemiological, clinical and magnetic resonance imaging findings of osteonecrosis in the distal femur and proximal tibia. Materials and methods: evaluation of 19 patients (12 women and 7 men), with no previous history of causative factors, with magnetic resonance imaging findings suggestive of osteonecrosis in the tibial plateau or femoral condyle. Results: osteochondral abnormalities were observed in 63.1% of the cases; in 73.6% of them, such abnormality was associated with ipsilateral meniscal lesion. Also, a significant association with bone marrow edema (grade III in 16 cases) was observed. Conclusion: magnetic resonance imaging has demonstrated to be a noninvasive method with good sensitivity in the diagnosis of knee osteonecrosis as well as of associated lesions which are most frequently found in women (63% of cases). (author)

Introduction lecture to magnetic resonance

International Nuclear Information System (INIS)

Conard, J.

1980-01-01

This lecture deals with all that is common either to electron paramagnetic resonance (E.P.R.) or to nuclear magnetic resonance (N.M.R.). It will present, in an as elementary form as possible, the main concepts used in magnetic resonance emphasizing some aspects, specific for interface science. (orig./BHO)

Normal and pathological findings for the facial nerve on magnetic resonance imaging

Energy Technology Data Exchange (ETDEWEB)

Al-Noury, K., E-mail: Kalnoury@kau.edu.sa [Department of Otolaryngology, King Abdulaziz University, Jeddah (Saudi Arabia); Lotfy, A. [Radiology Department, King Abdulaziz University Hospital and International Medical Centre, Jeddah (Saudi Arabia)

2011-08-15

Aim: To demonstrate the enhanced radiological anatomy and common pathological conditions of the facial nerve by using magnetic resonance imaging (MRI). Materials and methods: A retrospective review of the MRI findings of the facial nerve of 146 patients who visited a tertiary academic referral center was conducted. Results: The radiological anatomy of the facial nerve was well illustrated using MRI, as were most of the common pathological conditions of the facial nerve. Conclusions: Enhancement of the facial nerve in MRI should be correlated with the clinical data. Normal individuals can show enhancement of the tympanic or vertical segments of the facial nerve. Enhancement of the labyrinthine portion of the nerve is almost diagnostic of Bell's palsy. No specific enhancement patterns were observed for tumours or for infections of the middle or external ear. A larger population study is required for the accurate assessment of facial nerve enhancement in multiple sclerosis patients.

Hepatic involvement of Langerhans cell histiocytosis in children - imaging findings of computed tomography, magnetic resonance imaging and magnetic resonance cholangiopancreatography

International Nuclear Information System (INIS)

Shi, Yingyan; Qiao, Zhongwei; Gong, Ying; Yang, Haowei; Li, Guoping; Pa, Mier; Xia, Chunmei

2014-01-01

Langerhans cell histiocytosis is a rare disease that occurs mainly in children, and hepatic involvement is generally a poor prognostic factor. To describe CT and MRI findings of hepatic involvement of Langerhans cell histiocytosis in children, especially the abnormal bile duct manifestation on magnetic resonance cholangiopancreatography (MRCP). Thirteen children (seven boys, six girls; mean age 28.9 months) were diagnosed with disseminated Langerhans cell histiocytosis. They underwent CT (n = 5) or MRI (n = 4), or CT and MRI examinations (n = 4) to evaluate the liver involvement. Periportal abnormalities presented as band-like or nodular lesions on CT and MRI in all 13 children. The hepatic parenchymal lesions were found in the peripheral regions of the liver in seven children, including multiple nodules on MRI (n = 6), and cystic-like lesions on CT and MRI (n = 3). In 11 of the 13 children the dilatations of the bile ducts were observed on CT and MRI. Eight of the 13 children underwent MR cholangiopancreatography, which demonstrated stenoses or segmental stenoses with slight dilatation of the central bile ducts, including the common hepatic duct and its first-order branches. The peripheral bile ducts in these children showed segmental dilatations and stenoses. Stenosis of the central bile ducts revealed by MR cholangiopancreatography was the most significant finding of liver involvement in Langerhans cell histiocytosis in children. (orig.)

Hepatic involvement of Langerhans cell histiocytosis in children - imaging findings of computed tomography, magnetic resonance imaging and magnetic resonance cholangiopancreatography

Energy Technology Data Exchange (ETDEWEB)

Shi, Yingyan; Qiao, Zhongwei; Gong, Ying; Yang, Haowei; Li, Guoping; Pa, Mier [Children' s Hospital of Fudan University, Department of Radiology, Shanghai (China); Xia, Chunmei [Shanghai Medical College of Fudan University, Physiology and Pathophysiology Department, Shanghai (China)

2014-06-15

Langerhans cell histiocytosis is a rare disease that occurs mainly in children, and hepatic involvement is generally a poor prognostic factor. To describe CT and MRI findings of hepatic involvement of Langerhans cell histiocytosis in children, especially the abnormal bile duct manifestation on magnetic resonance cholangiopancreatography (MRCP). Thirteen children (seven boys, six girls; mean age 28.9 months) were diagnosed with disseminated Langerhans cell histiocytosis. They underwent CT (n = 5) or MRI (n = 4), or CT and MRI examinations (n = 4) to evaluate the liver involvement. Periportal abnormalities presented as band-like or nodular lesions on CT and MRI in all 13 children. The hepatic parenchymal lesions were found in the peripheral regions of the liver in seven children, including multiple nodules on MRI (n = 6), and cystic-like lesions on CT and MRI (n = 3). In 11 of the 13 children the dilatations of the bile ducts were observed on CT and MRI. Eight of the 13 children underwent MR cholangiopancreatography, which demonstrated stenoses or segmental stenoses with slight dilatation of the central bile ducts, including the common hepatic duct and its first-order branches. The peripheral bile ducts in these children showed segmental dilatations and stenoses. Stenosis of the central bile ducts revealed by MR cholangiopancreatography was the most significant finding of liver involvement in Langerhans cell histiocytosis in children. (orig.)

Magnetic resonance and the diagnosis of short stature of hypothalamic-hypophyseal origin

International Nuclear Information System (INIS)

Vannelli, S.; Avataneo, T.; Benso, L.; Potenzoni, F.; Cirillo, S.; Mostert, M.; Bona, G.

1993-01-01

Magnetic resonance imaging was performed in 23 patients with short stature (7 had multiple pituitary hormone defect, 11 had isolated growth hormone deficiency and 5 had normal variant short stature) to investigate if there is a relation between magnetic resonance findings and results of endocrine tests. Magnetic resonance imaging of patients with multiple pituitary hormone deficiency or with serious isolated growth hormone deficiency (growth hormone 3μg/l) or with normal variant short stature, the technique revealed a normal or hypoplastic hypophysis. Magnetic resonance appears to be a useful second-level diagnostic tool in defining the type of alteration in growth defects of endocrine origin. 26 refs., 5 figs., 2 tabs

Bony vibration stimulation test combined with magnetic resonance imaging. Can discography be replaced?

Science.gov (United States)

Yrjämä, M; Tervonen, O; Kurunlahti, M; Vanharanta, H

1997-04-01

The results of two noninvasive methods, magnetic resonance imaging and a bony vibration test, were compared with discographic pain provocation findings. To evaluate whether the combination of magnetic resonance imaging and vibration pain provocation tests could be used to replace discography in low back pain diagnostics. Magnetic resonance imaging gives a wealth of visual information on anatomic changes of the spine with often unknown clinical significance. Discographic examination of the spine is still the only widely accepted diagnostic method that can relate the pathoanatomic changes to the patient's clinical pain. Internal anular rupture has been shown to be one of the sources of back pain. The bony vibration test of the spinal processes has been shown correlate well with discographic pain provocation tests in cases of internal anular rupture. The three lowest lumbar discs of 33 patients with back pain were examined by means of magnetic resonance imaging and a bony vibration stimulation test, and the results were compared with those from computed tomography-discography. In cases of intradiscal magnetic resonance imaging findings, the vibration provocation test showed a sensitivity of 0.88 and a specificity of 0.50 compared with the discographic pain provocation test. If the patients with previous back surgery were excluded, the specificity was 0.75. In the cases of total anular rupture, the sensitivity was 0.50, and the specificity was 0.33. The combination of the two noninvasive methods, vibration stimulation and magnetic resonance imaging, gives more information on the origin of the back pain than magnetic resonance imaging alone. The pathoanatomic changes seen in magnetic resonance imaging can be correlated with the patient's disorder more reliably using the vibration provocation test in the cases of partial anular ruptures. The use of discography can be limited mostly to cases with total anular ruptures detected by magnetic resonance imaging.

Impact of magnetic resonance imaging on preoperative planning for breast cancer surgery.

Science.gov (United States)

Law, Y; Cheung, Polly S Y; Lau, Silvia; Lo, Gladys G

2013-08-01

To review the impact of preoperative breast magnetic resonance imaging on the management of planned surgery, and the appropriateness of any resulting alterations. Retrospective review. A private hospital in Hong Kong. PATIENTS; For the 147 consecutive biopsy-proven breast cancer patients who underwent preoperative magnetic resonance imaging to determine tumour extent undergoing operation by a single surgeon between 1 January 2006 and 31 December 2009, the impact of magnetic resonance imaging findings was reviewed in terms of management alterations and their appropriateness. The most common indication for breast magnetic resonance imaging was the presence of multiple indeterminate shadows on ultrasound scans (53%), followed by ill-defined border of the main tumour on ultrasound scans (19%). In 66% (97 out of 147) of the patients, the extent of the operation was upgraded. Upgrading entailed: lumpectomy to wider lumpectomy (23 out of 97), lumpectomy to mastectomy (47 out of 97), lumpectomy to bilateral lumpectomy (15 out of 97), and other (12 out of 97). Mostly, these management changes were because magnetic resonance imaging showed more extensive disease (n=29), additional cancer foci (n=39), or contralateral disease (n=24). In five instances, upgrading was due to patient preference. In 34% (50 out of 147) of the patients, there was no change in the planned operation. Regarding 97 of the patients having altered management, in 12 the changes were considered inappropriately extensive (due to false-positive magnetic resonance imaging findings). In terms of magnetic resonance imaging detection of more extensive, multifocal, multicentric, or contralateral disease, the false-positive rate was 13% and false-negative rate 7%. Corresponding rates for sensitivity and specificity were 95% and 81%, using the final pathology as the gold standard. Preoperative magnetic resonance imaging had a clinically significant and mostly correct impact on management plans. Magnetic resonance

Novel Anterior Brainstem Magnetic Resonance Imaging Findings in Non-Small Cell Lung Cancer with Leptomeningeal Carcinomatosis

Directory of Open Access Journals (Sweden)

Chun-Yu Cheng

2017-10-01

Full Text Available Leptomeningeal carcinomatosis (LC is found in around 4% of patients with non-small cell lung cancer (NSCLC. The most common radiological finding of LC is diffuse leptomeningeal enhancement on contrast-enhanced brain magnetic resonance imaging (MRI. Herein, we report a novel brain MRI finding—non-enhanced, band-like, symmetric restricted diffusion along the anterior surface of the brainstem—of LC in four patients with NSCLC. We also identified three additional cases with similar MRI findings in a literature review. We hypothesized that the restricted diffusion along the anterior brainstem was caused by malignant cells concentrating in the cistern around the brainstem and infiltrating into the circumferential perforating arteries along the anterior brainstem surface, which then resulted in microinfarctions.

Advances in magnetic resonance 9

CERN Document Server

Waugh, John S

2013-01-01

Advances in Magnetic Resonance, Volume 9 describes the magnetic resonance in split constants and dipolar relaxation. This book discusses the temperature-dependent splitting constants in the ESR spectra of organic free radicals; temperature-dependent splittings in ion pairs; and magnetic resonance induced by electrons. The electron impact excitation of atoms and molecules; intramolecular dipolar relaxation in multi-spin systems; and dipolar cross-correlation problem are also elaborated. This text likewise covers the NMR studies of molecules oriented in thermotropic liquid crystals and diffusion

A comparison of magnetic resonance arthrography and arthroscopic findings in the assessment of anterior shoulder dislocations

Energy Technology Data Exchange (ETDEWEB)

Jordan, R.W.; Naeem, R.; Srinivas, K.; Shyamalan, G. [Birmingham Heartlands Hospital, Birmingham (United Kingdom)

2015-05-01

The aim of this study is to establish the sensitivity and specificity of MRA in the investigation of patients with traumatic anterior shoulder dislocations. A retrospective analysis of consecutive patients undergoing both magnetic resonance arthrography and arthroscopic assessment after a traumatic anterior shoulder dislocation between January 2011 and 2014 was performed. Demographic data were collected from electronic records. Images were interpreted by 8 musculoskeletal radiologists and patients were treated by 8 consultant orthopaedic surgeons. Arthroscopic findings were obtained from surgical notes and these findings were used as a reference for MRA. The sensitivity, specificity, and positive predictive value were calculated for the different injuries. Sixty-nine patients underwent both an MRA and shoulder arthroscopy during the study period; however, clinical notes were unavailable in 9 patients. Fifty-three patients (88 %) were male, the mean age was 28 years (range 18 to 50) and 16 subjects (27 %) had suffered a primary dislocation. The overall sensitivity and specificity of MRA to all associated injuries was 0.9 (CI 0.83-0.95) and 0.94 (CI 0.9-0.96) retrospectively. The lowest sensitivity was seen in osseous Bankart 0.8 (CI 0.44-0.96) and superior labral tear (SLAP) lesions 0.5 (CI 0.14-0.86). The overall positive predictive value was 0.88 (CI 0.76-0.91) with the lowest values found in rotator cuff 0.4 (CI 0.07-0.83) and glenohumeral ligament (GHL) lesions 0.29 (CI 0.05-0.7). Magnetic resonance angiography has a high sensitivity when used to identify associated injuries in shoulder dislocation, although in 8 patients (13 %) arthroscopy identified an additional injury. The overall agreement between MRA and arthroscopic findings was good, but the identification of GHL and rotator cuff injuries was poor. (orig.)

A comparison of magnetic resonance arthrography and arthroscopic findings in the assessment of anterior shoulder dislocations

International Nuclear Information System (INIS)

Jordan, R.W.; Naeem, R.; Srinivas, K.; Shyamalan, G.

2015-01-01

The aim of this study is to establish the sensitivity and specificity of MRA in the investigation of patients with traumatic anterior shoulder dislocations. A retrospective analysis of consecutive patients undergoing both magnetic resonance arthrography and arthroscopic assessment after a traumatic anterior shoulder dislocation between January 2011 and 2014 was performed. Demographic data were collected from electronic records. Images were interpreted by 8 musculoskeletal radiologists and patients were treated by 8 consultant orthopaedic surgeons. Arthroscopic findings were obtained from surgical notes and these findings were used as a reference for MRA. The sensitivity, specificity, and positive predictive value were calculated for the different injuries. Sixty-nine patients underwent both an MRA and shoulder arthroscopy during the study period; however, clinical notes were unavailable in 9 patients. Fifty-three patients (88 %) were male, the mean age was 28 years (range 18 to 50) and 16 subjects (27 %) had suffered a primary dislocation. The overall sensitivity and specificity of MRA to all associated injuries was 0.9 (CI 0.83-0.95) and 0.94 (CI 0.9-0.96) retrospectively. The lowest sensitivity was seen in osseous Bankart 0.8 (CI 0.44-0.96) and superior labral tear (SLAP) lesions 0.5 (CI 0.14-0.86). The overall positive predictive value was 0.88 (CI 0.76-0.91) with the lowest values found in rotator cuff 0.4 (CI 0.07-0.83) and glenohumeral ligament (GHL) lesions 0.29 (CI 0.05-0.7). Magnetic resonance angiography has a high sensitivity when used to identify associated injuries in shoulder dislocation, although in 8 patients (13 %) arthroscopy identified an additional injury. The overall agreement between MRA and arthroscopic findings was good, but the identification of GHL and rotator cuff injuries was poor. (orig.)

Magnetic resonance imaging of aneurysmal subarachnoid hemorrhage

International Nuclear Information System (INIS)

Ogawa, Toshihide; Shimosegawa, Eku; Inugami, Atsushi; Shishido, Fumio; Fujita, Hideaki; Ito, Hiroshi; Uemura, Kazuo; Yasui, Nobuyuki

1991-01-01

Magnetic resonance imaging of subarachnoid hemorrhage (SAH) due to aneurysm rupture was evaluated in relation to CT findings in nine patients. Six patients were studied within 3 days and the other three patients were studied 4 to 6 days from the ictus of SAH using a 0.5 Tesla superconducting unit. In all of the patients, hematoma in the subarachnoid space and ventricles was demonstrated by the proton density-weighted spin echo sequence, which showed that bloody cerebrospinal fluid (CSF) had a higher signal intensity than brain tissue or normal CSF. Magnetic resonance imaging was more sensitive in detecting SAH and more informative as to the site of the ruptured aneurysm than CT. Despite some limitations in applying it to patients with acute SAH, magnetic resonace imaging has clear advantages in the diagnosis of SAH. (author)

Magnetic resonance imaging of aneurysmal subarachnoid hemorrhage

Energy Technology Data Exchange (ETDEWEB)

Ogawa, Toshihide; Shimosegawa, Eku; Inugami, Atsushi; Shishido, Fumio; Fujita, Hideaki; Ito, Hiroshi; Uemura, Kazuo; Yasui, Nobuyuki (Research Inst. of Brain and Blood Vessels, Akita (Japan))

1991-11-01

Magnetic resonance imaging of subarachnoid hemorrhage (SAH) due to aneurysm rupture was evaluated in relation to CT findings in nine patients. Six patients were studied within 3 days and the other three patients were studied 4 to 6 days from the ictus of SAH using a 0.5 Tesla superconducting unit. In all of the patients, hematoma in the subarachnoid space and ventricles was demonstrated by the proton density-weighted spin echo sequence, which showed that bloody cerebrospinal fluid (CSF) had a higher signal intensity than brain tissue or normal CSF. Magnetic resonance imaging was more sensitive in detecting SAH and more informative as to the site of the ruptured aneurysm than CT. Despite some limitations in applying it to patients with acute SAH, magnetic resonace imaging has clear advantages in the diagnosis of SAH. (author).

Magnetic Resonance Imaging (MRI) Safety

Science.gov (United States)

... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) Safety What is MRI and how ... What is MRI and how does it work? Magnetic resonance imaging, or MRI, is a way of obtaining ...

Magnetic resonance study of maghemite-based magnetic fluid

International Nuclear Information System (INIS)

Figueiredo, L.C.; Lacava, B.M.; Skeff Neto, K.; Pelegrini, F.; Morais, P.C.

2008-01-01

This study reports on the magnetic resonance (MR) data (X-band experiment) of 10.2 nm average diameter maghemite nanoparticle in the temperature range of 100-230 K. Maghemite nanoparticles were suspended as low-pH ionic magnetic fluid containing 2.3x10 17 particles/cm 3 . The temperature dependence of both resonance linewidth and resonance field of the zero-field-cooled sample as well as the resonance field of the field-cooled sample (angular variation experiment) was analyzed using well-established methodology. Information regarding particle size, particle clusterization and surface magnetic anisotropy were obtained from the analysis of the MR data. The number of magnetic sites per particle from the MR data is in excellent agreement with the number provided by the transmission electron microscopy (TEM) data. The demagnetizing field value obtained from the MR data indicates cluster of particles containing on average 1.42 particles. The MR angular variation data suggest that magnetoelastic effect accounts for the non-linearity observed for the surface component of the magnetic anisotropy

Advances in magnetic resonance 1

CERN Document Server

Waugh, John S

2013-01-01

Advances in Magnetic Resonance, Volume 1, discusses developments in various areas of magnetic resonance. The subject matter ranges from original theoretical contributions through syntheses of points of view toward series of phenomena to critical and painstaking tabulations of experimental data. The book contains six chapters and begins with a discussion of the theory of relaxation processes. This is followed by separate chapters on the development of magnetic resonance techniques for studying rate processes in chemistry and the application of these techniques to various problems; the geometri

Resonant and nonresonant magnetic scattering (invited)

International Nuclear Information System (INIS)

McWhan, D.B.; Hastings, J.B.; Kao, C.; Siddons, D.P.

1992-01-01

The tunability and the polarization of synchrotron radiation open up new possibilities for the study of magnetism. Studies on magnetic materials performed at the National Synchrotron Light Source are reviewed, and they fall into four areas: structure, evolution of magnetic order, separation of L and S, and resonance effects. In the vicinity of atomic absorption edges, the Faraday effect, magnetic circular dichroism, and resonant magnetic scattering are all related resonance effects which measure the spin-polarized density of states. The production and analysis of polarized beams are discussed in the context of the study of magnetism with synchrotron radiation

Magnetic resonance angiography in meningovascular syphilis

Energy Technology Data Exchange (ETDEWEB)

Gallego, J [Servicio de Neurologia, Hospital de Navarra and Pamplona Univ. Hospital (Spain); Soriano, G [Servicio de Neurologia, Hospital de Navarra and Pamplona Univ. Hospital (Spain); Zubieta, J L [Servicio de Neuroradiologia, Hospital de Navarra and Pamplona Univ. Hospital (Spain); Delgado, G [Servicio de Neurologia, Hospital de Navarra and Pamplona Univ. Hospital (Spain); Villanueva, J A [Servicio de Neurologia, Hospital de Navarra and Pamplona Univ. Hospital (Spain)

1994-04-01

Meningovascular neurosyphilis (MN) is an unusual cause of stroke in young adults. The clinical manifestations include prodromal symptoms weeks or months before definitive stroke. The diagnosis is based on clinical findings and examination of the serum and cerebrospinal fluid. We report a case of MN with basilar artery irregularities demonstrated by magnetic resonance angiography. (orig.)

Magnetic resonance angiography in meningovascular syphilis

International Nuclear Information System (INIS)

Gallego, J.; Soriano, G.; Zubieta, J.L.; Delgado, G.; Villanueva, J.A.

1994-01-01

Meningovascular neurosyphilis (MN) is an unusual cause of stroke in young adults. The clinical manifestations include prodromal symptoms weeks or months before definitive stroke. The diagnosis is based on clinical findings and examination of the serum and cerebrospinal fluid. We report a case of MN with basilar artery irregularities demonstrated by magnetic resonance angiography. (orig.)

A superconducting magnet for whole-body magnetic-resonance imaging

International Nuclear Information System (INIS)

Kan, Hisao; Watanabe, Tsugio; Takechi, Moriaki; Ogino, Osamu; Yamada, Tadatoshi

1986-01-01

Magnetic-resonance imaging is a promising new clinical diagnosis system that employs magnetic resonance to generate cross-sectional images of the object under examination. A large magnet plays a critical role in this system-it must supply a high-strength magnetic field that meets rigid standards of space and time uniformity. Mitsubishi Electric has developed a superconducting magnet that not only offers excellent magnetic characteristics but also features reduced helium consumption and a horizontal service port, and permits direct mounting of a magnetic shield. (author)

Magnetic Resonance Imaging (MRI) -- Head

Medline Plus

Full Text Available ... for Brain Tumors Radiation Therapy for Head and Neck Cancer Others : American Stroke Association National Stroke Association ... MRA) Magnetic Resonance, Functional (fMRI) - Brain Head and Neck Cancer Treatment Brain Tumor Treatment Magnetic Resonance Imaging ( ...

Magnetic Resonance Imaging of Stroke

NARCIS (Netherlands)

Bouts, Mark. J. R. J.; Wu, O.; Dijkhuizen, R. M.

2017-01-01

Magnetic resonance imaging (MRI) provides a powerful (neuro)imaging modality for the diagnosis and outcome prediction after (acute) stroke. Since MRI allows noninvasive, longitudinal, and three-dimensional assessment of vessel occlusion (with magnetic resonance angiography (MRA)), tissue injury

Magnetic resonance elastometry using a single-sided permanent magnet

International Nuclear Information System (INIS)

Tan, Carl S; Marble, Andrew E; Ono, Yuu

2012-01-01

In this paper, we describe a magnetic resonance method of measuring material elasticity using a single-sided magnet with a permanent static field gradient. This method encodes sample velocity in a reciprocal space using Hahn spin-echoes with variable timing. The experimental results show a strong correlation between magnetic resonance signal attenuation and elasticity when an oscillating force is applied on the sample. This relationship in turn provides us with information about the displacement velocity experienced by the sample, which is inversely proportional to Young's modulus. The proposed method shows promise in offering a portable and cost-effective magnetic resonance elastography system. (paper)

Magnetic x-ray linear dichroism in resonant and non-resonant Gd 4f photoemission

Energy Technology Data Exchange (ETDEWEB)

Mishra, S.; Gammon, W.J.; Pappas, D.P. [Virginia Commonwealth Univ., Richmond, VA (United States)] [and others

1997-04-01

The enhancement of the magnetic linear dichroism in resonant 4f photoemission (MLDRPE) is studied from a 50 monolayer film of Gd/Y(0001). The ALS at beamline 7.0.1 provided the source of linearly polarized x-rays used in this study. The polarized light was incident at an angle of 30 degrees relative to the film plane, and the sample magnetization was perpendicular to the photon polarization. The linear dichroism of the 4f core levels is measured as the photon energy is tuned through the 4d-4f resonance. The authors find that the MLDRPE asymmetry is strongest at the resonance. Near the threshold the asymmetry has several features which are out of phase with the fine structure of the total yield.

Magnetic x-ray linear dichroism in resonant and non-resonant Gd 4f photoemission

International Nuclear Information System (INIS)

Mishra, S.; Gammon, W.J.; Pappas, D.P.

1997-01-01

The enhancement of the magnetic linear dichroism in resonant 4f photoemission (MLDRPE) is studied from a 50 monolayer film of Gd/Y(0001). The ALS at beamline 7.0.1 provided the source of linearly polarized x-rays used in this study. The polarized light was incident at an angle of 30 degrees relative to the film plane, and the sample magnetization was perpendicular to the photon polarization. The linear dichroism of the 4f core levels is measured as the photon energy is tuned through the 4d-4f resonance. The authors find that the MLDRPE asymmetry is strongest at the resonance. Near the threshold the asymmetry has several features which are out of phase with the fine structure of the total yield

Children's (Pediatric) Magnetic Resonance Imaging

Medline Plus

Full Text Available ... Resources Professions Site Index A-Z Children’s (Pediatric) Magnetic Resonance Imaging Children’s magnetic resonance imaging (MRI) uses ... identify and accurately characterize diseases than other imaging methods. This detail makes MRI an invaluable tool in ...

Tunable Magnetic Resonance in Microwave Spintronics Devices

Science.gov (United States)

Chen, Yunpeng; Fan, Xin; Xie, Yunsong; Zhou, Yang; Wang, Tao; Wilson, Jeffrey D.; Simons, Rainee N.; Chui, Sui-Tat; Xiao, John Q.

2015-01-01

Magnetic resonance is one of the key properties of magnetic materials for the application of microwave spintronics devices. The conventional method for tuning magnetic resonance is to use an electromagnet, which provides very limited tuning range. Hence, the quest for enhancing the magnetic resonance tuning range without using an electromagnet has attracted tremendous attention. In this paper, we exploit the huge exchange coupling field between magnetic interlayers, which is on the order of 4000 Oe and also the high frequency modes of coupled oscillators to enhance the tuning range. Furthermore, we demonstrate a new scheme to control the magnetic resonance frequency. Moreover, we report a shift in the magnetic resonance frequency as high as 20 GHz in CoFe based tunable microwave spintronics devices, which is 10X higher than conventional methods.

Placenta Increta after First-Trimester Dilatation and Curettage Manifesting as an Unusual Uterine Mass: Magnetic Resonance Findings

Energy Technology Data Exchange (ETDEWEB)

Ju, W.; Kim, S.C. [Dept. of Obstetrics and Gynecology, and Medical Research Inst., School of Medicine, Ewha Womens Univ., Seoul (Korea)

2007-10-15

Placenta increta during the first trimester of pregnancy is extremely rare. Only a few cases of placenta accreta during the latter half of pregnancy manifesting as a uterine mass have been published. This report describes a case of placenta increta that caused prolonged bleeding after a first-trimester abortion, and was identified by magnetic resonance imaging (MRI) as a heterogeneous mass in the myometrium. This is the first report of a placenta increta detected as a uterine mass after first-trimester dilatation and curettage, and its MRI findings.

Children's (Pediatric) Magnetic Resonance Imaging

Medline Plus

Full Text Available ... Resources Professions Site Index A-Z Children’s (Pediatric) Magnetic Resonance Imaging Children’s magnetic resonance imaging (MRI) uses a powerful ... for an MRI exam contains a metal called gadolinium . Gadolinium can be used in patients with iodine ...

Children's (Pediatric) Magnetic Resonance Imaging

Medline Plus

Full Text Available ... work? Unlike conventional x-ray examinations and computed tomography (CT) scans, MRI does not utilize ionizing radiation. Instead, ... Angiography Magnetic Resonance, Functional (fMRI) - Brain Children's (Pediatric) CT (Computed Tomography) Magnetic Resonance Imaging (MRI) Safety Contrast Materials Children ...

Fourier transform nuclear magnetic resonance

International Nuclear Information System (INIS)

Geick, R.

1981-01-01

This review starts with the basic principles of resonance phenomena in physical systems. Especially, the connection is shown between the properties of these systems and Fourier transforms. Next, we discuss the principles of nuclear magnetic resonance. Starting from the general properties of physical systems showing resonance phenomena and from the special properties of nuclear spin systems, the main part of this paper reviews pulse and Fourier methods in nuclear magnetic resonance. Among pulse methods, an introduction will be given to spin echoes, and, apart from the principle of Fourier transform nuclear magnetic resonance, an introduction to the technical problems of this method, e.g. resolution in the frequency domain, aliasing, phase and intensity errors, stationary state of the spin systems for repetitive measurements, proton decoupling, and application of Fourier methods to systems in a nonequilibrium state. The last section is devoted to special applications of Fourier methods and recent developments, e.g. measurement of relaxation times, solvent peak suppression, 'rapid scan'-method, methods for suppressing the effects of dipolar coupling in solids, two-dimensional Fourier transform nuclear magnetic resonance, and spin mapping or zeugmatography. (author)

Does magnetic resonance imaging predict future low back pain?

DEFF Research Database (Denmark)

Steffens, D; Hancock, M J; Maher, C G

2014-01-01

Magnetic resonance imaging (MRI) has the potential to identify pathology responsible for low back pain (LBP). However, the importance of findings on MRI remains controversial. We aimed to systematically review whether MRI findings of the lumbar spine predict future LBP in different samples...

Chronological Evolution of Magnetic Resonance Imaging Findings in Children With Febrile Infection-Related Epilepsy Syndrome.

Science.gov (United States)

Rivas-Coppola, Marianna S; Shah, Namrata; Choudhri, Asim F; Morgan, Robin; Wheless, James W

2016-02-01

To describe and analyze the chronological evolution of the radiological findings in seven children with febrile infection-related epilepsy syndrome. This is a retrospective study describing the radiological findings and evolution in seven children with febrile infection-related epilepsy syndrome who presented from 2009 to 2013. The children all fit the defined clinical criteria for febrile infection-related epilepsy syndrome; all had a history of normal psychomotor development who presented with acute-onset catastrophic partial status epilepticus associated with a febrile illness or unspecific infectious process. The children were identified from the author's weekly review of the pediatric inpatient service, and then the data were collected and analyzed retrospectively. Six males and one female ranging from 3 months to 9 years of age presented with status epilepticus preceded by a febrile illness. Extensive investigations for infectious, autoimmune, and metabolic etiologies were unremarkable. Multiple antiepileptic medications were attempted, including drug-induced coma in all of them, with poor response. Immunotherapy with intravenous steroids or intravenous immunoglobulin (three patients had both) was tried in six of seven patients with a poor response. Ketogenic diet was initiated in four of seven patients with limited response. Serial magnetic resonance imaging studies, done from the initial presentation through 18 months of follow-up, showed evolution from normal imaging to severe cerebral atrophy. Progressive cytotoxic edema involving mostly bilateral hippocampi and temporal lobes was appreciated in one to three weeks. At one month from seizure onset, mild to moderate cerebral atrophy and hippocampal sclerosis was appreciated that continued to progress over the next year. After six to twelve months, most of the patients showed moderate to severe cerebral atrophy and by one year, cerebellar atrophy was also appreciated. Febrile infection-related epilepsy

Clinical magnetic resonance imaging. Frequent incidental cerebral findings; Klinische Magnetresonanztomographie. Haeufige zerebrale Zufallsbefunde

Energy Technology Data Exchange (ETDEWEB)

Mueller, A.; Ditter, P.; Schild, H.H.; Hattingen, E. [Universitaetsklinikum Bonn, Funktionseinheit Neuroradiologie der Klinik fuer Radiologie, Bonn (Germany); Weidauer, S. [St.-Katharinen-Krankenhaus, Neurologische Klinik, Frankfurt/M (Germany)

2017-04-15

The increasing use of magnetic resonance imaging (MRI) in clinical diagnostics means that patients and physicians are confronted more often with incidental findings. In the literature there are fluctuating data on the incidence of such findings and guidelines concerning the further procedure exist in only very few cases, such as incidental aneurysms and pituitary adenomas. The diagnostic and therapeutic implications which can be derived from incidental findings depend on multiple factors, such as anatomical location, patient age, comorbidity and patient wishes. For this reason it often makes sense to refer patients with incidental findings to an interdisciplinary neurological center at an early stage. In this review frequent incidental cerebral findings, epidemiological data, imaging criteria and, where possible, recommendations for the further procedure are shown. (orig.) [German] Durch den gehaeuften Einsatz der MRT in der zerebralen Diagnostik werden Arzt und Patienten in zunehmendem Masse mit Zufallsbefunden, auch Nebenbefunde genannt, konfrontiert. In der Literatur existieren sehr schwankende Angaben zur Haeufigkeit solcher Zufallsbefunde. Nur fuer einzelne dieser Befunde, wie z. B. das inzidentelle Aneurysma oder das Hypophysenadenom, existieren Leitlinien fuer das weitere Prozedere. Die aus einem Zufallsbefund abzuleitenden diagnostischen und therapeutischen Konsequenzen sind von vielen Faktoren, wie z. B. der anatomischen Lage, dem Patientenalter, den Komorbiditaeten und dem Patientenwunsch abhaengig. Daher ist es oft sinnvoll, den Patienten mit einem Zufallsbefund fruehzeitig in einem interdisziplinaeren Neurozentrum vorzustellen. In der vorliegenden Arbeit werden haeufige zerebrale Zufallsbefunde mit epidemiologischen Daten, bildgebenden Kriterien und - wenn moeglich - Empfehlungen bzgl. des weiteren Vorgehens gezeigt. (orig.)

Magnetic resonance imaging and radiographic findings of seal finger

International Nuclear Information System (INIS)

Marjelund, S.; Tikkakoski, T.; Isokangas, M.; Raeisaenen, S.

2006-01-01

Purpose: To describe the magnetic resonance imaging (MRI) and radiographic findings of five patients with seal finger. Material and Methods: The MR images and radiographs of five patients with seal finger were retrospectively evaluated. MRI was performed on four patients in the subacute phase, and follow-up imaging was done on one of them at 5 months. One patient had MRI only at a later stage 5 years after onset. Radiographs were taken three times in the subacute phase and once at a later stage. One patient had had seal finger in another finger previously. Results: Short-tau inversion-recovery (STIR) sequence showed extensive subcutaneous soft tissue edema in all four patients in the subacute phase and tenosynovitis of the flexion tendons in two cases. Three patients had edema in 2-3 phalanges, and effusion in the distal interphalangeal (DIP) joint was seen in one case. At the later stage, no signal pathology in soft tissues or bones was seen in STIR images. In the subacute phase, radiographs showed digital soft-tissue swelling in three patients, and one patient had a narrowed DIP joint, periarticular osteoporosis, and a periosteal reaction. At the later stage, flexion contracture of the finger was seen. Conclusion: In addition to soft-tissue infection, seal finger causes bone marrow edema, tenosynovitis, and effusion in the interphalangeal joints visible as increased signal intensity in STIR images. Radiographs reveal periarticular osteoporosis with loss of cartilage in the subacute phase and flexion contracture at the later stage. MRI (STIR) allows more precise delineation of the inflammatory process compared to radiography

Magnetic resonance imaging and radiographic findings of seal finger

Energy Technology Data Exchange (ETDEWEB)

Marjelund, S.; Tikkakoski, T.; Isokangas, M.; Raeisaenen, S. [Oulu Univ. Hospital (Finland). Dept. of Radiology

2006-12-15

Purpose: To describe the magnetic resonance imaging (MRI) and radiographic findings of five patients with seal finger. Material and Methods: The MR images and radiographs of five patients with seal finger were retrospectively evaluated. MRI was performed on four patients in the subacute phase, and follow-up imaging was done on one of them at 5 months. One patient had MRI only at a later stage 5 years after onset. Radiographs were taken three times in the subacute phase and once at a later stage. One patient had had seal finger in another finger previously. Results: Short-tau inversion-recovery (STIR) sequence showed extensive subcutaneous soft tissue edema in all four patients in the subacute phase and tenosynovitis of the flexion tendons in two cases. Three patients had edema in 2-3 phalanges, and effusion in the distal interphalangeal (DIP) joint was seen in one case. At the later stage, no signal pathology in soft tissues or bones was seen in STIR images. In the subacute phase, radiographs showed digital soft-tissue swelling in three patients, and one patient had a narrowed DIP joint, periarticular osteoporosis, and a periosteal reaction. At the later stage, flexion contracture of the finger was seen. Conclusion: In addition to soft-tissue infection, seal finger causes bone marrow edema, tenosynovitis, and effusion in the interphalangeal joints visible as increased signal intensity in STIR images. Radiographs reveal periarticular osteoporosis with loss of cartilage in the subacute phase and flexion contracture at the later stage. MRI (STIR) allows more precise delineation of the inflammatory process compared to radiography.

Nuclear magnetic resonance gyroscope

International Nuclear Information System (INIS)

Grover, B.C.

1984-01-01

A nuclear magnetic resonance gyro using two nuclear magnetic resonance gases, preferably xenon 129 and xenon 131, together with two alkaline metal vapors, preferably rubidium, potassium or cesium, one of the two alkaline metal vapors being pumped by light which has the wavelength of that alkaline metal vapor, and the other alkaline vapor being illuminated by light which has the wavelength of that other alkaline vapor

Magnetically coupled Fano resonance of dielectric pentamer oligomer

International Nuclear Information System (INIS)

Zhang, Fuli; Li, Chang; He, Xuan; Chen, Lei; Fan, Yuancheng; Zhao, Qian; Zhang, Weihong; Zhou, Ji

2017-01-01

We present magnetically induced Fano resonance inside a dielectric metamaterial pentamer composed of ceramic bricks. Unlike previous reports where different sizes of dielectric resonators were essential to produce Fano resonance, under external magnetic field excitation, central and outer dielectric bricks with identical sizes exhibit in-phase and out-of-phase magnetic Mie oscillations. An asymmetric line shape of Fano resonance along with enhanced group delay is observed due to the interference between the magnetic resonance of the central brick and the symmetric magnetic resonance of outer bricks. Besides, Fano resonance blueshifts with the increasing resonance of the smaller central brick. The thermal-dependent permittivity of ceramics allows Fano resonance to be reversibly tuned by 300 MHz when temperature varies by 60 °C. (paper)

Advances in mechanical detection of magnetic resonance

International Nuclear Information System (INIS)

Kuehn, Seppe; Hickman, Steven A.; Marohn, John A.

2008-01-01

The invention and initial demonstration of magnetic resonance force microscopy (MRFM) in the early 1990s launched a renaissance of mechanical approaches to detecting magnetic resonance. This article reviews progress made in MRFM in the last decade, including the demonstration of scanned probe detection of magnetic resonance (electron spin resonance, ferromagnetic resonance, and nuclear magnetic resonance) and the mechanical detection of electron spin resonance from a single spin. Force and force-gradient approaches to mechanical detection are reviewed and recent related work using attonewton sensitivity cantilevers to probe minute fluctuating electric fields near surfaces is discussed. Given recent progress, pushing MRFM to single proton sensitivity remains an exciting possibility. We will survey some practical and fundamental issues that must be resolved to meet this challenge.

Proton magnetic resonance spectroscopy in the fetus.

Science.gov (United States)

Story, Lisa; Damodaram, Mellisa S; Allsop, Joanna M; McGuinness, Amy; Wylezinska, Marzena; Kumar, Sailesh; Rutherford, Mary A

2011-09-01

Magnetic Resonance Imaging (MRI) has become an established technique in fetal medicine, providing complementary information to ultrasound in studies of the brain. MRI can provide detailed structural information irrespective of the position of the fetal head or maternal habitus. Proton Magnetic Resonance Spectroscopy ((1)HMRS) is based on the same physical principles as MRI but data are collected as a spectrum, allowing the biochemical and metabolic status of in vivo tissue to be studied in a non-invasive manner. (1)HMRS has been used to assess metabolic function in the neonatal brain but fetal studies have been limited, primarily due to fetal motion. This review will assess the technique and findings from fetal studies to date. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Magnetic resonance imaging findings in patients with peroneal tendinopathy and peroneal tenosynovitis

International Nuclear Information System (INIS)

Kijowski, Richard; Smet, Arthur de; Mukharjee, Rajat

2007-01-01

To compare the magnetic resonance (MR) imaging findings of a group of patients with clinically diagnosed peroneal tendonopathy and peroneal tenosynovitis with the MR imaging findings of a control group of patients with no clinical evidence of peroneal tendon disorder. The MR examinations of 24 patients with symptomatic peroneal tendinopathy or peroneal tenosynovitis and 70 patients with no clinical evidence of peroneal tendon disorder were retrospectively reviewed to determine the presence or absence of four MR imaging findings: 1) predominantly or uniform intermediate signal intensity within the peroneal tendons on one or more axial proton density-weighted images, 2) predominantly or uniform intermediate signal intensity within the peroneal tendons on three consecutive axial proton density-weighted images, 3) intermediate T2 signal intensity within the peroneal tendons, and 4) circumferential fluid within the common peroneal tendon sheath greater than 3 mm in maximal width. The sensitivity and specificity of these MR imaging findings for determining the presence or absence or symptomatic peroneal tendinopathy or peroneal tenosynovitis were calculated. The sensitivity of MR imaging findings 1, 2, 3, and 4 for determining the presence of peroneal tendinopathy or peroneal tenosynovitis were 92%, 92%, 50%, and 17% respectively. The specificity of MR imaging findings 1, 2, 3, and 4 for determining the absence of peroneal tendinopathy or peroneal tenosynovitis were 57%, 79%, 93%, and 100% respectively. The presence of predominantly or uniform intermediate signal intensity within the peroneal tendons on three consecutive axial proton density-weighted images is a highly sensitive and moderately specific indicator of symptomatic peroneal tendinopathy. The presence of intermediate T2 signal within the peroneal tendons, and the presence of circumferential fluid within the peroneal tendon sheath greater than 3 mm in maximal width, are highly specific indicators of peroneal

Magnetic resonance imaging findings in patients with peroneal tendinopathy and peroneal tenosynovitis

Energy Technology Data Exchange (ETDEWEB)

Kijowski, Richard; Smet, Arthur de [University of Wisconsin Hospital, Department of Radiology, Madison, WI (United States); Mukharjee, Rajat [University of Wisconsin Hospital, Department of Radiology, Madison, WI (United States); University of Wisconsin Hospital, Department of Statistics, Madison, WI (United States)

2007-02-15

To compare the magnetic resonance (MR) imaging findings of a group of patients with clinically diagnosed peroneal tendonopathy and peroneal tenosynovitis with the MR imaging findings of a control group of patients with no clinical evidence of peroneal tendon disorder. The MR examinations of 24 patients with symptomatic peroneal tendinopathy or peroneal tenosynovitis and 70 patients with no clinical evidence of peroneal tendon disorder were retrospectively reviewed to determine the presence or absence of four MR imaging findings: 1) predominantly or uniform intermediate signal intensity within the peroneal tendons on one or more axial proton density-weighted images, 2) predominantly or uniform intermediate signal intensity within the peroneal tendons on three consecutive axial proton density-weighted images, 3) intermediate T2 signal intensity within the peroneal tendons, and 4) circumferential fluid within the common peroneal tendon sheath greater than 3 mm in maximal width. The sensitivity and specificity of these MR imaging findings for determining the presence or absence or symptomatic peroneal tendinopathy or peroneal tenosynovitis were calculated. The sensitivity of MR imaging findings 1, 2, 3, and 4 for determining the presence of peroneal tendinopathy or peroneal tenosynovitis were 92%, 92%, 50%, and 17% respectively. The specificity of MR imaging findings 1, 2, 3, and 4 for determining the absence of peroneal tendinopathy or peroneal tenosynovitis were 57%, 79%, 93%, and 100% respectively. The presence of predominantly or uniform intermediate signal intensity within the peroneal tendons on three consecutive axial proton density-weighted images is a highly sensitive and moderately specific indicator of symptomatic peroneal tendinopathy. The presence of intermediate T2 signal within the peroneal tendons, and the presence of circumferential fluid within the peroneal tendon sheath greater than 3 mm in maximal width, are highly specific indicators of peroneal

Growth and adult height in GH-treated children with nonacquired GH deficiency and idiopathic short stature: the influence of pituitary magnetic resonance imaging findings.

Science.gov (United States)

Coutant, R; Rouleau, S; Despert, F; Magontier, N; Loisel, D; Limal, J M

2001-10-01

We analyzed the final height of 146 short children with either nonacquired GH deficiency or idiopathic short stature. Our purpose was 1) to assess growth according to the pituitary magnetic resonance imaging findings in the 63 GH-treated children with GH deficiency and 2) to compare the growth of the GH-deficient patients with normal magnetic resonance imaging (n = 48) to that of 32 treated and 51 untreated children with idiopathic short stature (GH peak to provocative tests >10 microg/liter). The mean GH dose was 0.44 IU/kg.wk (0.15 mg/kg.wk), given for a mean duration of 4.6 yr. Among the GH-deficient children, 15 had hypothalamic-pituitary abnormalities (stalk agenesis), all with total GH deficiency (GH peak imaging, had better catch-up growth (+2.7 +/- 0.9 vs. +1.3 +/- 0.8 SD score; P imaging, there was no difference in catch-up growth and final height between partial and total GH deficiencies. GH-deficient subjects with normal magnetic resonance imaging and treated and untreated patients with idiopathic short stature had comparable auxological characteristics, age at evaluation, and target height. Although they had different catch-up growth (+1.3 +/- 0.8, +0.9 +/- 0.6, and +0.7 +/- 0.9 SD score, respectively; P imaging findings show the heterogeneity within the group of nonacquired GH deficiency and help to predict the response to GH treatment in these patients. The similarities in growth between the GH-deficient children with normal magnetic resonance imaging and those with idiopathic short stature suggest that the short stature in the former subjects is at least partly due to factors other than GH deficiency.

Clinical, laboratory, psychiatric and magnetic resonance findings in patients with Sydenham chorea

International Nuclear Information System (INIS)

Faustino, Patricia C.; Terreri, Maria Teresa R.A.; Rocha, Antonio J. da; Zappitelli, Marcelo C.; Lederman, Henrique M.; Hilario, Maria Odete E.

2003-01-01

The objective of this study was to determine the clinical and laboratory characteristics, psychiatric manifestations and magnetic resonance imaging (MRI) findings in children and adolescents with Sydenham chorea (SyC). The imaging examination was repeated 1 year after the acute phase of SyC. There were 19 patients with a mean age of 11.7 years and a predominance of females (79%);68% had generalized chorea and 53% moderate chorea. SyC presented as an isolated manifestation in 74%. No association between SyC and obsessive-compulsive disorder was found. Mental health problems were present in 45% of the patients. MRI analysis revealed persistent alterations in the caudate nucleus in three patients (16%), who presented recurrent episodes of chorea during the study. In one patient, MRI revealed the presence of nodular heteropathy close to the caudate nucleus region. We conclude that attention problems can be associated with acute clinical features of SyC and persistent alterations in the basal nuclei, evidenced by MRI, can be found in some patients who tend to suffer prolonged attacks and a greater number of recurrences. (orig.)

Parenchymal abnormalities in cerebral venous thrombosis: findings of magnetic resonance imaging and magnetic resonance angiography; Alteracoes parenquimatosas na trombose venosa cerebral: aspectos da ressonancia magnetica e da angiorressonancia

Energy Technology Data Exchange (ETDEWEB)

Ferreira, Clecia Santos; Pellini, Marcos [Universidade Federal, Rio de Janeiro, RJ (Brazil). Faculdade de Medicina. Dept. de Radiologia]. E-mail: csferreira@superig.com.br; Boasquevisque, Edson [Universidade do Estado do Rio de Janeiro, (UERJ), RJ (Brazil). Faculdade de Medicina. Dept. de Patologia; Souza, Luis Alberto M. de [Hospital da Beneficencia Portuguesa do Rio de Janeiro, RJ (Brazil). Servico de Imagem. Setor de Ressonancia Magnetica

2006-09-15

Objective: to determine the frequency and localization of parenchymal abnormalities in cerebral venous thrombosis on magnetic resonance imaging and magnetic resonance angiography as well as their correlation with the territory and affected venous drainage. Materials and methods: retrospective analysis (1996 to 2004) of 21 patients (3 male and 18 female) age range between 3 and 82 years (mean 40 years, median 36 years) with clinical and radiological diagnosis of cerebral venous thrombosis on magnetic resonance imaging and magnetic resonance angiography in 2D PC, 3D PC and contrast-enhanced 3D TOF sequences. The statistical analysis was performed with the qui-square test. Four patients had follow-up exams and three patients underwent digital subtraction angiography. Results: main predisposing factors were: infection, use of oral contraceptives, hormone replacement therapy and collagenosis. Predominant symptoms included: focal deficit, headache, alteration of consciousness level and seizures. Most frequent parenchymal manifestations were: cortical/subcortical edema or infarct, venous congestion and collateral circulation, meningeal enhancement and thalamic and basal ganglia edema or infarct. Occlusion occurred mainly in superior sagittal, left transverse, left sigmoid and straight sinuses. Cavernous sinus and cortical veins thrombosis are uncommon events. Conclusion: cerebral venous thrombosis is an uncommon cause of stroke, with favorable prognosis because of its reversibility. Diagnosis is highly dependent on the radiologist capacity to recognize the presentations of this disease, principally in cases where the diagnosis is suggested by parenchymal abnormalities rather than necessarily by visualization of the thrombus itself. An accurate and rapid diagnosis allows an immediate treatment, reducing the morbidity and mortality rates. (author)

Investigation of magnetic interactions in sulfides by means of magnetic resonance

International Nuclear Information System (INIS)

Veen, G. van.

1978-01-01

Investigations have been designed to gather more information about magnetic pair interactions in sulfides by isomorphic substitution of the magnetic ions in suitable chosen diamagnetic host lattices and measurement of electron spin resonance of coupled pairs and of electron spin resonance or electron nuclear double resonance of the hyperfine interaction due to the nuclei of diamagnetic cations. The greater part of this thesis is devoted to preliminaries of magnetic resonance interpretation and sample selection and preparation. The measurements on the magnetically diluted compounds, which are described, only have an exploratory nature. (Auth.)

Magnetic resonance imaging the basics

CERN Document Server

Constantinides, Christakis

2014-01-01

Magnetic resonance imaging (MRI) is a rapidly developing field in basic applied science and clinical practice. Research efforts in this area have already been recognized with five Nobel prizes awarded to seven Nobel laureates in the past 70 years. Based on courses taught at The Johns Hopkins University, Magnetic Resonance Imaging: The Basics provides a solid introduction to this powerful technology. The book begins with a general description of the phenomenon of magnetic resonance and a brief summary of Fourier transformations in two dimensions. It examines the fundamental principles of physics for nuclear magnetic resonance (NMR) signal formation and image construction and provides a detailed explanation of the mathematical formulation of MRI. Numerous image quantitative indices are discussed, including (among others) signal, noise, signal-to-noise, contrast, and resolution. The second part of the book examines the hardware and electronics of an MRI scanner and the typical measurements and simulations of m...

Magnetic resonance imaging of xanthomatous meningioma

International Nuclear Information System (INIS)

Katayama, Y.; Tsubokawa, T.; Tanaka, A.; Koshinaga, M.; Nemoto, N.

1993-01-01

A case of meningioma with extensive xanthomatous metaplasia occurring in the left frontal convexity of a 37-year-old woman is reported. The tumour was demonstrated as a hypodense mass with minimal enhancement on CT. Our findings suggest that magnetic resonance imaging may provide a clue to the diagnosis of meningiomas with extensive xanthomatous metaplasia when CT is less specific. (orig.)

Reliability of gadolinium-enhanced magnetic resonance imaging findings and their correlation with clinical outcome in patients with sciatica.

Science.gov (United States)

el Barzouhi, Abdelilah; Vleggeert-Lankamp, Carmen L A M; Lycklama à Nijeholt, Geert J; Van der Kallen, Bas F; van den Hout, Wilbert B; Koes, Bart W; Peul, Wilco C

2014-11-01

Gadolinium-enhanced magnetic resonance imaging (Gd-MRI) is often performed in the evaluation of patients with persistent sciatica after lumbar disc surgery. However, correlation between enhancement and clinical findings is debated, and limited data are available regarding the reliability of enhancement findings. To evaluate the reliability of Gd-MRI findings and their correlation with clinical findings in patients with sciatica. Prospective observational evaluation of patients who were enrolled in a randomized trial with 1-year follow-up. Patients with 6- to 12-week sciatica, who participated in a multicentre randomized clinical trial comparing an early surgery strategy with prolonged conservative care with surgery if needed. In total 204 patients underwent Gd-MRI at baseline and after 1 year. Patients were assessed by means of the Roland Disability Questionnaire (RDQ) for sciatica, visual analog scale (VAS) for leg pain, and patient-reported perceived recovery at 1 year. Kappa coefficients were used to assess interobserver reliability. In total, 204 patients underwent Gd-MRI at baseline and after 1 year. Magnetic resonance imaging findings were correlated to the outcome measures using the Mann-Whitney U test for continuous data and Fisher exact tests for categorical data. Poor-to-moderate agreement was observed regarding Gd enhancement of the herniated disc and compressed nerve root (kappa0.95). Of the 59 patients with an enhancing herniated disc at 1 year, 86% reported recovery compared with 100% of the 12 patients with nonenhancing herniated discs (p=.34). Of the 12 patients with enhancement of the most affected nerve root at 1 year, 83% reported recovery compared with 85% of the 192 patients with no enhancement (p=.69). Patients with and without enhancing herniated discs or nerve roots at 1 year reported comparable outcomes on RDQ and VAS-leg pain. Reliability of Gd-MRI findings was poor-to-moderate and no correlation was observed between enhancement and

Dynamic study of pelvic floor in patients with constipation: dynamic magnetic resonance vs defecography

International Nuclear Information System (INIS)

Gonzalez Vasquez, Carlos Mario; Pulgarin, Ricardo Luis German; Melo Arango, Catalina; Delgado de Bedout, Jorge Andres; Llano Serna, Juan Fernando; Restrepo Restrepo, Jose Ignacio

2007-01-01

Purpose: to compare the concordance between defecography and magnetic resonance in patients with constipation. Materials and methods: we did a prospective and descriptive assay to determine the concordance of a diagnostic test with 17 patients. The evaluation of the studies was double blind. Results: the 17 patients were females, age range 31 - 77 year the symptoms were present between 3 to 120 months. Anterior rectocele was the most common diagnosis (11 patients) and magnetic resonance had sensibility 100%, specificity 50%, positive predictive value 78, 57% and negative predictive value 100%. 7 patients had pelvic floor descent and magnetic resonance had sensibility 71.4%, specificity 20% positive predictive value 38.46% and negative predictive value 50%. Defecography found patients with enterocele and magnetic resonance had sensibility 0% and specificity 100 anismus was present in 2 patients and magnetic resonance didn't find them. Conclusion defecography is still the gold standard for patients with eonstipation. Magnetic resonance are a promise for those patients but has to improve

[Magnetic resonance compatibility research for coronary mental stents].

Science.gov (United States)

Wang, Ying; Liu, Li; Wang, Shuo; Shang, Ruyao; Wang, Chunren

2015-01-01

The objective of this article is to research magnetic resonance compatibility for coronary mental stents, and to evaluate the magnetic resonance compatibility based on laboratory testing results. Coronary stents magnetic resonance compatibility test includes magnetically induced displacement force test, magnetically induced torque test, radio frequency induced heating and evaluation of MR image. By magnetic displacement force and torque values, temperature, and image distortion values to determine metal coronary stent demagnetization effect. The methods can be applied to test magnetic resonance compatibility for coronary mental stents and evaluate its demagnetization effect.

Magnetic resonance imaging findings compared with histological findings of the labrum in hip osteoarthritis

International Nuclear Information System (INIS)

Kanezaki, Shiho; Nakamura, Shigeru; Matsushita, Takashi; Yamamoto, Asako; Osawa, Marie

2015-01-01

Patients with disorders such as acetabular dysplasia or femoroacetabular impingement are at risk of developing hip osteoartbritis. Assessment of the cartilage and labrum in the hip joint based on magnetic resonance imaging (MRI) has been challenging because of the low signal-to-noise ratio (SNR) due to its deep location, ball and socket structure, and small volume of those structures compared with the whole joint size. To achieve better imaging assessment, direct MR. arthrography (d-MRA) and other techniques such as T2* mapping, T2 mapping, Tlrho, and delayed gadolinium-enhanced MRI (dGEMRIC) have been developed along with the increasing use of high-field MRI. In patients with no apparent osteoarthritic changes such as joint space narrowing or osteophyte and subchondral cyst formation on radiographs, these techniques can detect early cartilage or labral damage. A recently developed semiquantitative MRI-based scoring system for hip osteoarthritis includes evaluation of the labrum, and its application as a potential therapeutic monitoring tool is anticipated. The labrum shows pathological changes such as macroscopic hypertrophy and histological degeneration in hip osteoartbritis, but the pathological background is not well understood when evaluated by MRI. Kubo et al. compared radial MRI findings with histological changes of the labrum in ll hips with osteoarthritis using 1.5-T MRJ and found that fibrous separation and mucoid deposition occurred in the labrum with a ''diffuse high signal'' or ''obscure'' pattern. However, to the best of our knowledge, no studies have demonstrated a correlation between MRI fmdings and histological evidence of the severity of degeneration of the labrum. We hypothesized that radially reconstructed images of the acetabular labrum acquired by 3-T MRI can depict degenerative changes of the labrum. In this study, we sought to determine the correlation between MRI and histological findings of the

Magnetic resonance imaging findings compared with histological findings of the labrum in hip osteoarthritis

Energy Technology Data Exchange (ETDEWEB)

Kanezaki, Shiho; Nakamura, Shigeru; Matsushita, Takashi [Teikyo University School of Medicine, Department of Orthopaedic Surgery, Itabashi-ku, Tokyo (Japan); Yamamoto, Asako; Osawa, Marie [Teikyo University School of Medicine, Department of Radiology, Itabashi-ku, Tokyo (Japan)

2015-06-01

Patients with disorders such as acetabular dysplasia or femoroacetabular impingement are at risk of developing hip osteoartbritis. Assessment of the cartilage and labrum in the hip joint based on magnetic resonance imaging (MRI) has been challenging because of the low signal-to-noise ratio (SNR) due to its deep location, ball and socket structure, and small volume of those structures compared with the whole joint size. To achieve better imaging assessment, direct MR. arthrography (d-MRA) and other techniques such as T2* mapping, T2 mapping, Tlrho, and delayed gadolinium-enhanced MRI (dGEMRIC) have been developed along with the increasing use of high-field MRI. In patients with no apparent osteoarthritic changes such as joint space narrowing or osteophyte and subchondral cyst formation on radiographs, these techniques can detect early cartilage or labral damage. A recently developed semiquantitative MRI-based scoring system for hip osteoarthritis includes evaluation of the labrum, and its application as a potential therapeutic monitoring tool is anticipated. The labrum shows pathological changes such as macroscopic hypertrophy and histological degeneration in hip osteoartbritis, but the pathological background is not well understood when evaluated by MRI. Kubo et al. compared radial MRI findings with histological changes of the labrum in ll hips with osteoarthritis using 1.5-T MRJ and found that fibrous separation and mucoid deposition occurred in the labrum with a ''diffuse high signal'' or ''obscure'' pattern. However, to the best of our knowledge, no studies have demonstrated a correlation between MRI fmdings and histological evidence of the severity of degeneration of the labrum. We hypothesized that radially reconstructed images of the acetabular labrum acquired by 3-T MRI can depict degenerative changes of the labrum. In this study, we sought to determine the correlation between MRI and histological findings of the

Abdominal tuberculosis: a radiological review with emphasis on computed tomography and magnetic resonance imaging findings

Energy Technology Data Exchange (ETDEWEB)

Rocha, Eduardo Lima da; Pedrassa, Bruno Cheregati; Bormann, Renata Lilian; Kierszenbaum, Marcelo Longo; Torres, Lucas Rios; D' Ippolito, Giuseppe, E-mail: giuseppe_dr@uol.com.br [Universidade Federal de Sao Paulo (EPM/UNIFESP), Sao Paulo, SP (Brazil). Escola Paulista de Medicina

2015-05-15

Tuberculosis is a disease whose incidence has increased principally as a consequence of HIV infection and use of immunosuppressive drugs. The abdomen is the most common site of extrapulmonary tuberculosis. It may be confused with several different conditions such as inflammatory bowel disease, cancer and other infectious diseases. Delay in the diagnosis may result in significantly increased morbidity, and therefore an early recognition of the condition is essential for proper treatment. In the present essay, cases with confirmed diagnosis of abdominal tuberculosis were assessed by means of computed tomography and magnetic resonance imaging, demonstrating the involvement of different organs and systems, and presentations which frequently lead radiologists to a diagnostic dilemma. A brief literature review was focused on imaging findings and their respective prevalence. (author)

A Magnetic Resonance Measurement Technique for Rapidly Switched Gradient Magnetic Fields in a Magnetic Resonance Tomograph

Directory of Open Access Journals (Sweden)

K. Bartušek

2003-01-01

Full Text Available This paper describes a method for measuring of the gradient magnetic field in Nuclear Magnetic Resonance (NMR tomography, which is one of the modern medical diagnostic methods. A very important prerequisite for high quality imaging is a gradient magnetic field in the instrument with exactly defined properties. Nuclear magnetic resonance enables us to measure the pulse gradient magnetic field characteristics with high accuracy. These interesting precise methods were designed, realised, and tested at the Institute of Scientific Instruments (ISI of the Academy of Sciences of the Czech Republic. The first of them was the Instantaneous Frequency (IF method, which was developed into the Instantaneous Frequency of Spin Echo (IFSE and the Instantaneous Frequency of Spin Echo Series (IFSES methods. The above named methods are described in this paper and their a comparison is also presented.

Disc pathology after whiplash injury. A prospective magnetic resonance imaging and clinical investigation

International Nuclear Information System (INIS)

Pettersson, K.; Hildingsson, C.; Toolanen, G.; Fagerlund, M.; Bjornebrink, J.

1997-01-01

Although disc pathology seems to be one contributing factor in the development of chronic symptoms after whiplash injury, it may be unnecessary to examine these patients in the acute phase with magnetic resonance imaging ; correlating initial symptoms and signs to magnetic resonance imaging findings is difficult because of the relatively high proportion of false-positive results. Magnetic resonance imaging is indicated later in the course of treatment in patients with persistent arm pain, neurologic deficits, or clinical signs of nerve root compression to diagnose disc herniations requiring surgery. (authors)

The nuclear magnetic resonance well logging

International Nuclear Information System (INIS)

Zhang Yumin; Shen Huitang

2003-01-01

In this paper, the characteristic of the nuclear magnetic resonance logging is described at first. Then its development and its principle is presented. Compared with the nuclear magnetic resonance spectrometer, the magnet techniques is the first question that we must solve in the manufacture of the NMR well logging

Advances in magnetic and optical resonance

CERN Document Server

Warren, Warren S

1997-01-01

Since 1965, Advances in Magnetic and Optical Resonance has provided researchers with timely expositions of fundamental new developments in the theory of, experimentation with, and application of magnetic and optical resonance.

Magnetic resonance imaging of neonatal brain. Assessment of normal and abnormal findings

International Nuclear Information System (INIS)

Hasegawa, Koh; Kadono, Naoko; Kawase, Shohji; Kihara, Minako; Matsuo, Yasutaka; Yoshioka, Hiroshi; Kinugasa, Akihiko; Sawada, Tadashi

1994-01-01

To establish the normal MRI appearance of the neonatal brain, magnetic resonance imaging (MRI) was performed on 124 neonates who admitted to our neonatal intensive care unit. Degree of myelination, ventricular size, width of the extracerebral space and focal lesion in the brain were evaluated to investigate the relationship between MRI findings of neonatal brain and the neurological prognosis. 85 neonates underwent MRI both at neonatal period and at the corrected age of one year. The change of abnormal MRI findings was evaluated. 19 neonates had abnormal neurological outcome on subsequent examinations. Delayed myelination, ventriculomegaly and large extracerebral space were seen in 13, 7 and 9 neonates respectively. 4, 3 and 5 neonates out of them showed abnormal neurological prognosis respectively. Of the 19 neonates with focal lesion in MRI, 2 had parenchymal hematoma in the brain, 2 had subdural hematoma, 5 had chronic hematoma following subependymal hemorrhage, 6 had cystic formation following subependymal hemorrhage, 2 had subcortical leukomalacia, one had periventricular leukomalacia and one had cyst in the parenchyma of cerebellum. 4 neonates of 19 with focal lesion in MRI showed abnormal development. Of the neonates who had abnormal neurological prognosis, 7 neonates showed no abnormal finding in MRI at neonatal period. 3 of them had mild mental retardation. MRI shows promise in the neonatal period. It facilitates recognition of abnormalities of neonatal brain and may be used to predict abnormal neurologic outcome. However physiological change in the brain of neonates, especially of premature neonates, should be considered on interpreting these findings. Awareness of developmental features should help to minimize misinterpretation of normal changes in the neonatal brain. (author)

Magnetic resonance imaging of neonatal brain. Assessment of normal and abnormal findings

Energy Technology Data Exchange (ETDEWEB)

Hasegawa, Koh; Kadono, Naoko; Kawase, Shohji; Kihara, Minako; Matsuo, Yasutaka; Yoshioka, Hiroshi; Kinugasa, Akihiko; Sawada, Tadashi (Kyoto Prefectural Univ. of Medicine (Japan))

1994-11-01

To establish the normal MRI appearance of the neonatal brain, magnetic resonance imaging (MRI) was performed on 124 neonates who admitted to our neonatal intensive care unit. Degree of myelination, ventricular size, width of the extracerebral space and focal lesion in the brain were evaluated to investigate the relationship between MRI findings of neonatal brain and the neurological prognosis. 85 neonates underwent MRI both at neonatal period and at the corrected age of one year. The change of abnormal MRI findings was evaluated. 19 neonates had abnormal neurological outcome on subsequent examinations. Delayed myelination, ventriculomegaly and large extracerebral space were seen in 13, 7 and 9 neonates respectively. 4, 3 and 5 neonates out of them showed abnormal neurological prognosis respectively. Of the 19 neonates with focal lesion in MRI, 2 had parenchymal hematoma in the brain, 2 had subdural hematoma, 5 had chronic hematoma following subependymal hemorrhage, 6 had cystic formation following subependymal hemorrhage, 2 had subcortical leukomalacia, one had periventricular leukomalacia and one had cyst in the parenchyma of cerebellum. 4 neonates of 19 with focal lesion in MRI showed abnormal development. Of the neonates who had abnormal neurological prognosis, 7 neonates showed no abnormal finding in MRI at neonatal period. 3 of them had mild mental retardation. MRI shows promise in the neonatal period. It facilitates recognition of abnormalities of neonatal brain and may be used to predict abnormal neurologic outcome. However physiological change in the brain of neonates, especially of premature neonates, should be considered on interpreting these findings. Awareness of developmental features should help to minimize misinterpretation of normal changes in the neonatal brain. (author).

Embroidered Coils for Magnetic Resonance Sensors

Directory of Open Access Journals (Sweden)

Michael I. Newton

2013-04-01

Full Text Available Magnetic resonance imaging is a widely used technique for medical and materials imaging. Even though the objects being imaged are often irregularly shaped, suitable coils permitting the measurement of the radio-frequency signal in these systems are usually made of solid copper. One problem often encountered is how to ensure the coils are both in close proximity and conformal to the object being imaged. Whilst embroidered conductive threads have previously been used as antennae in mobile telecommunications applications, they have not previously been reported for use within magnetic resonance. In this paper we show that an embroidered single loop coil can be used in a commercial unilateral nuclear magnetic resonance system as an alternative to a solid copper. Data is presented showing the determination of both longitudinal (T1 and effective transverse (T2eff relaxation times for a flat fabric coil and the same coil conformed to an 8 cm diameter cylinder. We thereby demonstrate the principles required for the wider use of fabric based conformal coils within nuclear magnetic resonance and magnetic resonance imaging.

Magnetic resonance imaging in spondyloarthritis--how to quantify findings and measure response

DEFF Research Database (Denmark)

Østergaard, Mikkel; Poggenborg, René Panduro; Axelsen, Mette Bjørndal

2010-01-01

Sensitive and reliable tools for monitoring disease activity and damage, and for prognostication, are essential in the management of patients with spondyloarthritis, including ankylosing spondylitis and psoriatic arthritis. Magnetic resonance imaging (MRI) allows direct visualisation of inflammat...... and clinical practice. The present article reviews key aspects of the status and recent important advances in MRI in spondyloarthritis, focussing on available MRI tools for assessing activity and damage in peripheral and, particularly, axial joints....

Magnetic resonance imaging in lower urinary tract endometriosis: iconographic essay

International Nuclear Information System (INIS)

Lima, Claudio Marcio Amaral de Oliveira; Coutinho, Elisa Pompeu Dias; Ribeiro, Erica Barreiros; Domingues, Marisa Nassar Aidar; Junqueira, Flavia Pegado; Coutinho Junior, Antonio Carlos

2009-01-01

Endometriosis is defined as the presence of functional endometrial tissue outside the endometrial cavity and myometrium. Although this is a frequent disease with multifactorial causes, involvement of the lower urinary tract is rare. Magnetic resonance imaging is highly sensitive, specific and accurate in the diagnosis of endometriosis in the lower urinary tract, especially for allowing the identification of lesions obscured by adhesions or with subperitoneal extension. The present iconographic essay presents the main magnetic resonance imaging findings of the lower urinary tract involvement by endometriosis. (author)

Increasing Benefit of Magnetic Resonance Imaging in Multiple Sclerosis

International Nuclear Information System (INIS)

Pyhtinen, J.; Karttunen, A.; Tikkakoski, T.

2006-01-01

Magnetic resonance imaging (MRI) has emerged as an essential tool of multiple sclerosis (MS) diagnosis and has opened up completely new prospects in MS research and treatment trials. It is a sensitive method that gives direct evidence of tissue pathology and has greatly increased our knowledge of MS. In clinical work, MRI is used to confirm and exclude the diagnosis of MS. The international recommendation is that every suspected MS patient should undergo at least one brain MRI. T2-weighted images are the standard tool in clinical work, and functional imaging methods are mainly used in MS research. The subtypes and the course of the disease cause variation in MRI findings. Here, we present a general overview of MR findings in MS. Brain, magnetic resonance imaging, multiple sclerosis, spinal cord

Increasing Benefit of Magnetic Resonance Imaging in Multiple Sclerosis

Energy Technology Data Exchange (ETDEWEB)

Pyhtinen, J.; Karttunen, A.; Tikkakoski, T. [Radiologian Klinikka, Oulu (Finland)

2006-11-15

Magnetic resonance imaging (MRI) has emerged as an essential tool of multiple sclerosis (MS) diagnosis and has opened up completely new prospects in MS research and treatment trials. It is a sensitive method that gives direct evidence of tissue pathology and has greatly increased our knowledge of MS. In clinical work, MRI is used to confirm and exclude the diagnosis of MS. The international recommendation is that every suspected MS patient should undergo at least one brain MRI. T2-weighted images are the standard tool in clinical work, and functional imaging methods are mainly used in MS research. The subtypes and the course of the disease cause variation in MRI findings. Here, we present a general overview of MR findings in MS. Brain, magnetic resonance imaging, multiple sclerosis, spinal cord.

Nuclear magnetic resonance imaging

International Nuclear Information System (INIS)

Young, I.R.

1984-01-01

In a method of imaging a body in which nuclear magnetic resonance is excited in a region including part of the body, and the free induction decay signal is measured, a known quantity of a material of known nuclear magnetic resonance properties, for example a bag of water, is included in the region so as to enhance the measured free induction decay signal. This then reduces the generation of noise during subsequent processing of the signal. (author)

Nuclear magnetic resonance diagnostic apparatus

International Nuclear Information System (INIS)

Sugimoto, H.

1985-01-01

Nuclear magnetic resonance diagnostic apparatus including a coil for generating a gradient field in a plane perpendicular to a static magnetic field, means for controlling the operation of the coil to rotationally shift in angular steps the gradient direction of the gradient field at an angle pitch of some multiple of the unit index angle through a plurality of rotations to assume all the shift positions of the gradient direction, a rough image reconstructor for reconstructing a rough tomographic image on the basis of nuclear magnetic resonance signals acquired during a rotation of the second gradient magnetic field, a rough image display for depicting the rough tomographic image, a final image reconstructor for reconstructing a final tomographic image on the basis of all nuclear magnetic resonance signals corresponding to all of the expected rotation shift positions acquired during a plurality of rotations and a final image display for depicting the final tomographic image

Nuclear magnetic resonance apparatus

International Nuclear Information System (INIS)

Lambert, R.

1991-01-01

In order to include the effect of a magnetic object in a subject under investigation, Nuclear Magnetic Resonance (NMR) apparatus is operable at more than one radio frequency (RF) frequency. The apparatus allows normal practice as far as obtaining an NMR response or image from a given nuclear species is concerned, but, in addition, interrogates the nuclear spin system at a frequency which is different from the resonance frequency normally used for the given nuclear species, as determined from the applied magnetic field. The magnetic field close to a magnetised or magnetisable object is modified and the given nuclear species gives a response at the different frequency. Thus detection of a signal at the frequency indicates the presence of the chosen nuclei close to the magnetised or magnetisable object. Applications include validation of an object detection or automatic shape inspection system in the presence of magnetic impurities, and the detection of magnetic particles which affect measurement of liquid flow in a pipe. (author)

Respiratory syncytial virus-related encephalitis: magnetic resonance imaging findings with diffusion-weighted study

International Nuclear Information System (INIS)

Park, Arim; Suh, Sang-il; Seol, Hae-Young; Son, Gyu-Ri; Lee, Nam-Joon; Lee, Young Hen; Seo, Hyung Suk; Eun, Baik-Lin

2014-01-01

Respiratory syncytial virus (RSV) is a common pathogen causing acute respiratory infection in children. Herein, we describe the incidence and clinical and magnetic resonance imaging (MRI) findings of RSV-related encephalitis, a major neurological complication of RSV infection. We retrospectively reviewed the medical records and imaging findings of the patients over the past 7 years who are admitted to our medical center and are tested positive for RSV-RNA by reverse transcriptase PCR. In total, 3,856 patients were diagnosed with RSV bronchiolitis, and 28 of them underwent brain MRI for the evaluation of neurologic symptoms; 8 of these 28 patients had positive imaging findings. Five of these 8 patients were excluded because of non-RSV-related pathologies, such as subdural hemorrhage, brain volume loss due to status epilepticus, periventricular leukomalacia, preexisting ventriculomegaly, and hypoxic brain injury. The incidence of RSV-related encephalitis was as follows: 3/3,856 (0.08 %) of the patients are positive for RSV RNA, 3/28 (10.7 %) of the patient underwent brain MRI for neurological symptom, and 3/8 (37.5 %) of patients revealed abnormal MR findings. The imaging findings were suggestive of patterns of rhombenmesencephalitis, encephalitis with acute disseminated encephalomyelitis, and limbic encephalitis. They demonstrated no diffusion abnormality on diffusion-weighted image and symptom improvement on the follow-up study. Encephalitis with RSV bronchiolitis occurs rarely. However, on brain MRI performed upon suspicion of neurologic involvement, RSV encephalitis is not infrequently observed among the abnormal MR findings and may mimic other viral and limbic encephalitis. Physicians should be aware of this entity to ensure proper diagnosis and neurologic care of RSV-positive patients. (orig.)

Respiratory syncytial virus-related encephalitis: magnetic resonance imaging findings with diffusion-weighted study

Energy Technology Data Exchange (ETDEWEB)

Park, Arim; Suh, Sang-il; Seol, Hae-Young [Korea University College of Medicine, Department of Radiology, Korea University Guro Hospital, Seoul (Korea, Republic of); Son, Gyu-Ri; Lee, Nam-Joon [Korea University College of Medicine, Department of Radiology, Korea University Anam Hospital, Seoul (Korea, Republic of); Lee, Young Hen; Seo, Hyung Suk [Korea University College of Medicine, Department of Radiology, Korea University Ansan Hospital, Gyeonggi-do (Korea, Republic of); Eun, Baik-Lin [Korea University College of Medicine, Department of Pediatrics, Korea University Guro Hospital, Seoul (Korea, Republic of)

2014-02-15

Respiratory syncytial virus (RSV) is a common pathogen causing acute respiratory infection in children. Herein, we describe the incidence and clinical and magnetic resonance imaging (MRI) findings of RSV-related encephalitis, a major neurological complication of RSV infection. We retrospectively reviewed the medical records and imaging findings of the patients over the past 7 years who are admitted to our medical center and are tested positive for RSV-RNA by reverse transcriptase PCR. In total, 3,856 patients were diagnosed with RSV bronchiolitis, and 28 of them underwent brain MRI for the evaluation of neurologic symptoms; 8 of these 28 patients had positive imaging findings. Five of these 8 patients were excluded because of non-RSV-related pathologies, such as subdural hemorrhage, brain volume loss due to status epilepticus, periventricular leukomalacia, preexisting ventriculomegaly, and hypoxic brain injury. The incidence of RSV-related encephalitis was as follows: 3/3,856 (0.08 %) of the patients are positive for RSV RNA, 3/28 (10.7 %) of the patient underwent brain MRI for neurological symptom, and 3/8 (37.5 %) of patients revealed abnormal MR findings. The imaging findings were suggestive of patterns of rhombenmesencephalitis, encephalitis with acute disseminated encephalomyelitis, and limbic encephalitis. They demonstrated no diffusion abnormality on diffusion-weighted image and symptom improvement on the follow-up study. Encephalitis with RSV bronchiolitis occurs rarely. However, on brain MRI performed upon suspicion of neurologic involvement, RSV encephalitis is not infrequently observed among the abnormal MR findings and may mimic other viral and limbic encephalitis. Physicians should be aware of this entity to ensure proper diagnosis and neurologic care of RSV-positive patients. (orig.)

Magnetic resonance imaging of the liver in postpartum stable women with HELLP syndrome

International Nuclear Information System (INIS)

Carvalho, Ana Rita Marinho Ribeiro; Amorim, Melania Maria Ramos de; Katz, Leila; Souza, Alex Sandro Rolland de; Santos, Aleksana Regina Viana Dutra; Lima, Ana Luiza Medeiros Vasconcelos de

2008-01-01

Objectives: To describe magnetic resonance (MR) findings in the liver of stable patients with HELLP syndrome in the puerperium. Methods: A descriptive study was carried out from August 2005 to July 2006, involving a series of 40 postpartum patients admitted to an obstetric intensive therapy unit in IMIP (Instituto Materno Infantil Prof. Fernando Figueira) with diagnosis of HELLP syndrome (complete and partial). Complete HELLP syndrome was defined when all laboratory parameters were present and incomplete when one or more but not all laboratory findings were present. All patients had stable clinical conditions and were evaluated with magnetic resonance of the liver and the main findings were recorded. Results. Average maternal age was 26.8 ± 6.4 years and gestational age at delivery was 34 ± 26.8 weeks. The MR imaging was performed between eight and 96 hours after diagnosis of HELLP syndrome (56 ± 31h). The most frequent findings were ascitis in 20% (n = 8), pleural effusion in 17.5% and hepatic steatosis in 7.5%. The periportal intensity signal was normal in all cases. Cases of liver infarction and sub-capsular or parenchymatous hematoma were not observed. Conclusion: Findings of magnetic resonance imaging of the liver in stable HELLP syndrome postpartum patients were few and unspecific. Severe liver injuries such as parenchymatous or sub-capsular hematoma, entailing life risk were not found. Results do not corroborate the use of magnetic resonance as routine examination for stable patients with HELLP syndrome. (author)

Corpus callosum dysgenesis and lipoma: embryologic and magnetic resonance imaging aspects

International Nuclear Information System (INIS)

Abreu Junior, Luiz de; Borri, Maria Lucia; Wolosker, Angela Maria Borri; Hartmann, Luiz Guilherme de Carvalho; Galvao Filho, Mario de Melo; D'Ippolito, Giuseppe

2005-01-01

The corpus callosum is the major system of association fibers that permits communication of both cerebral hemispheres. Magnetic resonance imaging has improved the study of brain malformations, including the corpus callosum dysgenesis. Lipoma is a common finding in the spectrum of corpus callosum dysgenesis. The purpose of these study was to review the embryologic events and the magnetic resonance imaging aspects related to the corpus callosum dysgenesis and to the formation of the related lipoma. (author)

Cardiac magnetic resonance radiofrequency tissue tagging for diagnosis of constrictive pericarditis: A proof of concept study.

Science.gov (United States)

Power, John A; Thompson, Diane V; Rayarao, Geetha; Doyle, Mark; Biederman, Robert W W

2016-05-01

Invasive cardiac catheterization is the venerable "gold standard" for diagnosing constrictive pericarditis. However, its sensitivity and specificity vary dramatically from center to center. Given the ability to unequivocally define segments of the pericardium with the heart via radiofrequency tissue tagging, we hypothesize that cardiac magnetic resonance has the capability to be the new gold standard. All patients who were referred for cardiac magnetic resonance evaluation of constrictive pericarditis underwent cardiac magnetic resonance radiofrequency tissue tagging to define visceral-parietal pericardial adherence to determine constriction. This was then compared with intraoperative surgical findings. Likewise, all preoperative cardiac catheterization testing was reviewed in a blinded manner. A total of 120 patients were referred for clinical suspicion of constrictive pericarditis. Thirty-nine patients were defined as constrictive pericarditis positive solely via radiofrequency tissue-tagging cardiac magnetic resonance, of whom 21 were positive, 4 were negative, and 1 was equivocal for constrictive pericarditis, as defined by cardiac catheterization. Of these patients, 16 underwent pericardiectomy and were surgically confirmed. There was 100% agreement between cardiac magnetic resonance-defined constrictive pericarditis positivity and postsurgical findings. No patients were misclassified by cardiac magnetic resonance. In regard to the remaining constrictive pericarditis-positive patients defined by cardiac magnetic resonance, 10 were treated medically, declined, were ineligible for surgery, or were lost to follow-up. Long-term follow-up of those who were constrictive pericarditis negative by cardiac magnetic resonance showed no early or late crossover to the surgery arm. Cardiac magnetic resonance via radiofrequency tissue tagging offers a unique, efficient, and effective manner of defining clinically and surgically relevant constrictive pericarditis

A clinical study and the diagnosis in magnetic resonance imaging of renal scarring

International Nuclear Information System (INIS)

Tsugaya, Masayuki; Hirao, Noriaki; Ohtaguro, Kazuo; Kato, Jiro.

1989-01-01

Twenty-nine kidneys of seventeen patients (nine boys and eight girls) with vesicoureteral reflux and repeated urinary tract infection were studied by magnetic resonance imaging for diagnosis of renal scarring and correlation between clinical data and the degree renal scarring. Renal scarring is classified into three types according to findings in magnetic resonance imaging. The degree of renal scarring are classified into five grades according to traditional grading of intravenous pyelogram. If a fine deformity of calyx is shown on intravenous pyelogram, magnetic resonance imaging demonstrates renal scarring. Magnetic resonance imaging without irradiation is exceedingly valuable for the diagnosis of renal scarring. The appearances of magnetic resonance imaging were supported by X-ray computed tomography. There is a substantial correlation between serum creatinine and the grades of renal scarring by magnetic resonance imaging. There is a substantial correlation between fever attacks and the grade of renal scarring, and there is a significant reverse correlation between the age of the onset of upper urinary tract infection and the grade of renal scarring. It is suggested that upper urinary tract infection is the most significant factor in scar formation. (author)

Parameter dependence of resonant spin torque magnetization reversal

International Nuclear Information System (INIS)

Fricke, L.; Serrano-Guisan, S.; Schumacher, H.W.

2012-01-01

We numerically study ultra fast resonant spin torque (ST) magnetization reversal in magnetic tunneling junctions (MTJ) driven by current pulses having a direct current (DC) and a resonant alternating current (AC) component. The precessional ST dynamics of the single domain MTJ free layer cell are modeled in the macro spin approximation. The energy efficiency, reversal time, and reversal reliability are investigated under variation of pulse parameters like direct and AC current amplitude, AC frequency and AC phase. We find a range of AC and direct current amplitudes where robust resonant ST reversal is obtained with faster switching time and reduced energy consumption per pulse compared to purely direct current ST reversal. However, for a certain range of AC and direct current amplitudes a strong dependence of the reversal properties on AC frequency and phase is found. Such regions of unreliable reversal must be avoided for ST memory applications.

Parameter dependence of resonant spin torque magnetization reversal

Science.gov (United States)

Fricke, L.; Serrano-Guisan, S.; Schumacher, H. W.

2012-04-01

We numerically study ultra fast resonant spin torque (ST) magnetization reversal in magnetic tunneling junctions (MTJ) driven by current pulses having a direct current (DC) and a resonant alternating current (AC) component. The precessional ST dynamics of the single domain MTJ free layer cell are modeled in the macro spin approximation. The energy efficiency, reversal time, and reversal reliability are investigated under variation of pulse parameters like direct and AC current amplitude, AC frequency and AC phase. We find a range of AC and direct current amplitudes where robust resonant ST reversal is obtained with faster switching time and reduced energy consumption per pulse compared to purely direct current ST reversal. However, for a certain range of AC and direct current amplitudes a strong dependence of the reversal properties on AC frequency and phase is found. Such regions of unreliable reversal must be avoided for ST memory applications.

Magnetic resonance and porous materials

International Nuclear Information System (INIS)

McDonald, P.; Strange, J.

1998-01-01

Mention the words magnetic resonance to your medical advisor and he or she will immediately think of a multi-million pound scanner that peers deep into the brain. A chemist, on the other hand, will imagine a machine that costs several hundred thousand pounds and produces high-resolution spectra for chemical analysis. Food technologists will probably think of a bench-top instrument for determining moisture content, while an oil prospector will envisage a device that can be operated several kilometres down an oil well. To a physicist the term is more likely to conjure up a mental picture of nuclear spins precessing in a magnetic field. These examples illustrate the diverse aspects of a phenomenon discovered by physicists over 50 years ago. Electron spin resonance was first discovered by Russian scientists, and nuclear magnetic resonance was discovered in the US shortly afterwards by Ed Purcell at Harvard University and Felix Bloch at Stanford University. Today, nuclear magnetic resonance (NMR) is the most widely used technique. Modern NMR machines are making it possible to probe microstructure and molecular movement in materials as diverse as polymers, cements, rocks, soil and foods. NMR allows the distribution of different components in a material to be determined with a resolution approaching 1μm, although the signal can be sensitive to even smaller lengthscales. In this article the authors describe how physicists are still developing magnetic resonance to exploit a range of new applications. (UK)

Magnetic resonance imaging by using nano-magnetic particles

Energy Technology Data Exchange (ETDEWEB)

Shokrollahi, H., E-mail: Shokrollahi@sutech.ac.ir [Electroceramics Group, Department of Materials Science and Engineering, Shiraz University of Technology, Shiraz (Iran, Islamic Republic of); Khorramdin, A. [Electroceramics Group, Department of Materials Science and Engineering, Shiraz University of Technology, Shiraz (Iran, Islamic Republic of); Isapour, Gh. [Department of Materials and Engineering, Hakim Sabzevari University (Iran, Islamic Republic of)

2014-11-15

Magnetism and magnetic materials play a major role in various biological applications, such as magnetic bioseparation, magnetic resonance imaging (MRI), hyperthermia treatment of cancer and drug delivery. Among these techniques, MRI is a powerful method not only for diagnostic radiology but also for therapeutic medicine that utilizes a magnetic field and radio waves. Recently, this technique has contributed greatly to the promotion of the human quality life. Thus, this paper presents a short review of the physical principles and recent advances of MRI, as well as providing a summary of the synthesis methods and properties of contrast agents, like different core materials and surfactants. - Highlights: • This paper studies the physics of MRI as a powerful diagnostic technique. • MRI uses the differentiation between healthy and pathological tissues. • The relaxation times can be shortened by the use of a magnetic contrast agent. • The magnetic nanoparticles act as contrast agents, helping to increase the resolution. • Different synthesis methods can influence the magnetic resonance behavior.

Cardiac magnetic resonance imaging in clinical practice

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Adriana Dias Barranhas

2014-01-01

Full Text Available Objective To evaluate and describe indications, mainly diagnoses and cardiac magnetic resonance imaging findings observed in clinical practice. Materials and Methods Retrospective and descriptive study of cardiac magnetic resonance performed at a private hospital and clinic in the city of Niterói, RJ, Brazil, in the period from May 2007 to April 2011. Results The sample included a total of 1000 studies performed in patients with a mean age of 53.7 ± 16.2 years and predominance for male gender (57.2%. The majority of indications were related to assessment of myocardial perfusion at rest and under pharmacological stress (507/1000; 51%, with positive results in 36.2% of them. Suspected myocarditis was the second most frequent indication (140/1000; 14%, with positive results in 63.4% of cases. These two indications were followed by study of arrhythmias (116/1000; 12%, myocardial viability (69/1000; 7% and evaluation of cardiomyopathies (47/1000; 5%. In a subanalysis, it was possible to identify that most patients were assessed on an outpatient basis (58.42%. Conclusion Cardiac magnetic resonance has been routinely performed in clinical practice, either on an outpatient or emergency/inpatient basis, and myocardial ischemia represented the main indication, followed by investigation of myocarditis, arrhythmogenic right ventricular dysplasia and myocardial viability.

Magnetic resonance imaging of the pediatric airway

International Nuclear Information System (INIS)

Auringer, S.T.; Bisset, G.S. III; Myer, C.M.

1991-01-01

Evaluation of the pediatric airway is often complex and may require multiple imaging techniques and invasive procedures. We performed magnetic resonance (MR) imaging of the airway in 34 children with clinical evidence of chronic airway obstruction and compared MR findings with those obtained by surgery and/or endoscopy. MR diagnoses included vascular compression in 15 patients, primary tracheomalacic states in 12 patients, and mediastinal masses in 4 patients. Findings were normal for 3 patients. The MR findings were in agreement with the endoscopic findings in 25 to 28 cases and in agreement with the surgical findings in 21 to 21 cases. (orig./GDG)

Magnetic resonance tomography of renal allografts - Diagnostic possibilities

International Nuclear Information System (INIS)

Dewey, C.; Luening, M.

1988-01-01

It is the aim of the use of magnetic resonance tomography (MRT) to reduce the existing insufficiency in imaging diagnostics of complications after kidney transplantation. The topical status of examination technique is presented and the criteria of normal and pathological MRT findings are described in detail. (author)

Magnetic resonance imaging of the prostate

DEFF Research Database (Denmark)

Iversen, P; Kjaer, L; Thomsen, C

1988-01-01

Magnetic resonance imaging offers new possibilities in investigation of the prostate gland. Current results of imaging and tissue discrimination in the evaluation of prostatic disease are reviewed. Magnetic resonance imaging may be useful in the staging of carcinoma of the prostate....

Usefulness of magnetic resonance imaging in diagnosis of varicocele

International Nuclear Information System (INIS)

Akiyama, Hironobu; Nagai, Atsushi; Ichikawa, Takaharu; Oeda, Tadashi; Nasu, Yasutomo; Ohmori, Hiroyuki; Togami, Izumi; Katoh, Katsuya; Hiraki, Yoshio

1996-01-01

Magnetic resonance imaging (MRI) was applied for diagnosis of varicocele testis. Twelve of fourteen patients with varicocele had positive findings on MRI. In addition, four of seven patients with clinically undetectable varicocele had positive findings on MRI. We think MRI is one of the useful means for detection of varicocele including subclinical form. (author)

Magnetic resonance imaging of the prostate

DEFF Research Database (Denmark)

Iversen, P; Kjaer, L; Thomsen, C

1987-01-01

Magnetic resonance imaging offers new possibilities in the investigation of the prostate. The current results of imaging and tissue discrimination in the evaluation of prostatic disease are reviewed. Magnetic resonance imaging may be of value in the staging of carcinoma of the prostate....

Magnetic resonance of low dimensional magnetic solids

Energy Technology Data Exchange (ETDEWEB)

Gatteschi, D.; Ferraro, F.; Sessoli, R. (Florence Univ. (Italy))

1994-06-01

The utility of EPR and NMR in the study of low-dimensional magnetic solids is shown. A short summary of the basis of magnetic resonance in these systems is reported, and the importance of spin-diffusion and magnetic anisotropy evidenced. Some results from experiments on metal-radical chains and clusters are presented. (authors). 37 refs., 7 figs.

Magnetic resonance of low dimensional magnetic solids

International Nuclear Information System (INIS)

Gatteschi, D.; Ferraro, F.; Sessoli, R.

1994-01-01

The utility of EPR and NMR in the study of low-dimensional magnetic solids is shown. A short summary of the basis of magnetic resonance in these systems is reported, and the importance of spin-diffusion and magnetic anisotropy evidenced. Some results from experiments on metal-radical chains and clusters are presented. (authors). 37 refs., 7 figs

The value of fetal ultrasonography and magnetic resonance imaging in the assessment of diaphragmatic hernias

International Nuclear Information System (INIS)

Amim, Bruno; Guerra, Fernando; Marchiori, Edson; Gasparetto, Emerson Leandro

2008-01-01

To demonstrate the relevance of ultrasonography and magnetic resonance imaging findings in the prenatal characterization and prognostic evaluation in cases of congenital diaphragmatic hernia. Materials And Methods: Fourteen pregnant women (mean gestational age = 28.7 weeks) who had undergone ultrasonography for suspicion of fetuses with congenital diaphragmatic hernia were assessed by means of magnetic resonance imaging on a 1.5 tesla equipment, following the standard protocol. Two radiologists evaluated the images and the findings were defined by consensus. Results: Twelve fetuses had left diaphragmatic hernia and two, right diaphragmatic hernia. Ultrasonography showed the fetal liver inside the thorax of five fetuses (three with left diaphragmatic hernia, and two with right diaphragmatic hernia) and magnetic resonance imaging in eight fetuses (six with left diaphragmatic hernia, and two with right diaphragmatic hernia). Stomach and small bowel loop herniation was observed in all of the fetuses with left diaphragmatic hernia (n = 12) at both magnetic resonance imaging and ultrasonography. Eight fetuses (seven with left diaphragmatic hernia and one with right diaphragmatic hernia) survived after surgical treatment. Conclusion: Ultrasonography and magnetic resonance imaging are complementary imaging methods in the evaluation of congenital diaphragmatic hernia. Magnetic resonance imaging is a helpful diagnostic method complementary to ultrasonography for evaluation of the fetal liver positioning, considering its relevance as a prognostic factor in cases of congenital diaphragmatic hernia. (author)

The nuclear magnetic resonance spectroscopy

International Nuclear Information System (INIS)

Goyer, Ph.

1997-01-01

The spectroscopy of nuclear magnetic resonance constitutes a major analytical technique in biological and organic analysis. This technique appears now in the programme of preparatory classes and its teaching is developed in the second year of DEUG. The following article reviews on the nuclear magnetic resonance and on the possibilities it offers to bring to the fore the physico-chemical properties of molecules. (N.C.)

Advances in magnetic resonance 2

CERN Document Server

Waugh, John S

2013-01-01

Advances in Magnetic Resonance, Volume 2, features a mixture of experimental and theoretical contributions. The book contains four chapters and begins with an ambitious and general treatment of the problem of signal-to-noise ratio in magnetic resonance. This is followed by separate chapters on the interpretation of nuclear relaxation in fluids, with special reference to hydrogen; and various aspects of molecular theory of importance in NMR.

Magnetic resonance annual, 1988

International Nuclear Information System (INIS)

Kressel, H.Y.

1987-01-01

This book features reviews of high-resolution MRI of the knee, MRI of the normal and ischmeic hip, MRI of the heart, and temporomandibular joint imaging, as well as thorough discussion on artifacts in magnetic resonance imaging. Contributors consider the clinical applications of gadolinium-DTPA in magnetic resonance imaging and the clinical use of partial saturation and saturation recovery sequences. Timely reports assess the current status of rapid MRI and describe a new rapid gated cine MRI technique. Also included is an analysis of cerebrospinal fluid flow effects during MRI of the central nervous system

Magnetic resonance angiography

Science.gov (United States)

... Saunders; 2015:chap 17. Litt H, Carpenter JP. Magnetic resonance imaging. In: Cronenwett JL, Johnston KW, eds. Rutherford's Vascular Surgery . 8th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap ...

Children's (Pediatric) Magnetic Resonance Imaging

Medline Plus

Full Text Available ... magnetic resonance imaging (MRI) uses a powerful magnetic field, radio waves and a computer to produce detailed ... problems, medications, recent surgeries and allergies. The magnetic field is not harmful, but it may cause some ...

Cortical magnetic resonance imaging findings in familial pediatric bipolar disorder.

Science.gov (United States)

Chang, Kiki; Barnea-Goraly, Naama; Karchemskiy, Asya; Simeonova, Diana Iorgova; Barnes, Patrick; Ketter, Terence; Reiss, Allan L

2005-08-01

Morphometric magnetic resonance imaging (MRI) studies of pediatric bipolar disorder (BD) have not reported on gray matter volumes but have reported increased lateral ventricular size and presence of white matter hyperintensities (WMH). We studied gray matter volume, ventricular-to-brain ratios (VBR), and number of WMH in patients with familial, pediatric BD compared with control subjects. Twenty subjects with BD (aged 14.6 +/- 2.8 years; 4 female) according to the Washington University in St. Louis Kiddie Schedule for Affective Disorders and Schizophrenia, each with a parent with BD, and 20 age-, gender-, and intelligence quotient-matched healthy control subjects (aged 14.1 +/- 2.8 years; 4 female) were scanned at 3 T. Most subjects were taking psychotropic medications. A high-resolution T1-weighted spoiled gradient echo three-dimensional MRI sequence was analyzed by BrainImage for volumetric measurements, and T2-weighted images were read by a neuroradiologist to determine presence of WMH. After covarying for age and total brain volume, there were no significant differences between subjects with BD and control subjects in volume of cerebral (p = .09) or prefrontal gray matter (p = .34). Subjects with BD did not have elevated numbers of WMH or greater VBR when compared with control subjects. Children and adolescents with familial BD do not seem to have decreased cerebral grey matter or increased numbers of WMH, dissimilar to findings in adults with BD. Gray matter decreases and development of WMH might be later sequelae of BD or unique to adult-onset BD.

Magnetic resonance imaging findings as predictors of clinical outcome in patients with sciatica receiving active conservative treatment

DEFF Research Database (Denmark)

Jensen, Tue Secher; Albert, Hanne B; Sorensen, Joan S

2007-01-01

OBJECTIVE: The aims of this study were to investigate the possible prognostic value of disk-related magnetic resonance imaging (MRI) findings in relation to recovery at 14 months in patients with severe sciatica, and whether improvement of disk herniation and/or nerve root compromise is concurrent...... with recovery. METHODS: All patients included in this prospective observational study of patients with sciatica receiving active conservative treatment were scanned at baseline and at 14 months' follow-up. Definite recovery at follow-up was defined as an absence of sciatic leg pain and a Roland Morris...... in that the prevalence of disk-related MRI findings was different for men and women, and they had different recovery rates. Improvement of disk herniations and nerve root compromise over time did not coincide with definite recovery. CONCLUSIONS: In patients with sciatica receiving active conservative treatment, broad...

Magnetic resonance imaging of the central nervous system. Comparison with X-ray CT

Energy Technology Data Exchange (ETDEWEB)

Kajima, Toshio; Kagawa, Yoshihiro; Katsuta, Shizutomo.

1987-06-01

Magnetic resonance imaging (MRI) and X-ray computed tomography (X-ray CT) have been performed in 169 consecutive patients with central nervous system diseases. The findings from the two methods were compared for the capacity to defect lesions. Magnetic resonance imaging was more sensitive than or equivalent to X-ray CT in detecting lesions - especially detecting. Arnold-Chiari malformation, syringomyelia, spinal cord injury, and pituitary adenoma - in 158 patients (94 %). In six patients (10 %), lesion detection was possible only by MRI. Magnetic resonance imaging was inferior to X-ray CT in 11 patients (7 %) in detecting calcified lesions, meningioma, and cavernous hemangioma. (Namekawa, K.).

Magnetic resonance imaging: hazard, risk and safety

International Nuclear Information System (INIS)

Narayan, Pradeep; Suri, S.; Singh, P.

2001-01-01

The hazard and risk associated with magnetic resonance imaging is a matter of concern. In 1982, the Food and Drug Administration (FDA), USA issued guidelines to Hospital's Investigational Review Board (IRBs) in 'Guidelines for Evaluating Electromagnetic Exposure Risks for Trials of Clinical Nuclear Magnetic Resonance (NMR)'. In 1997, the Berufsgenossenschaft (BG), professional association for precision engineering and electronics of Germany, in their preliminary proposal for safety limits extended their concerns on static magnetic field. Owing to both time varying and static magnetic fields applied in Magnetic Resonance Imaging (MRI) this became of immediate concern to user community to assess the potential hazard and risk associated with the NMR system

Magnetic resonance phenomena in dynamics of relativistic particles

International Nuclear Information System (INIS)

Ternov, I.M.; Bordovitsyn, V.A.

1987-01-01

A relativistic generalization of Rabi's formula for magnetic resonance is given. On this basis, we consider fast and slow passage through resonance. We define a magnetic resonance exterior field as usual, using unit vectors of a Cartesian coordinate system, a homogeneous magnetic field, and the amplitude of a rotating magnetic field. For the description of spin dynamics we use the Bargmann-Michel-Telegdi equation

Magnetic resonance in multiple sclerose twins

International Nuclear Information System (INIS)

Polman, C.H.; UitdeHaag, B.M.J.; Koetsier, C.J.; Valk, J.; Lucas, C.J.

1989-01-01

Magnetic resonance imaging (MR) examinations were performed in a series of 7 twin sets (4 monozygotic and 3 dizygotic) and one triplet set who were clinically discordant for multiple sclerosis (MS). MRI abnormalities were detected in a number of the unaffected members of the nonzygotic twin pairs. The authors discuss the possible implications of their findings for the present view on the aetiology of MS. (author). 3 refs.; 1 fig.; 1 tab

Magnetic resonance imaging in sudden deafness

International Nuclear Information System (INIS)

Ramos, Hugo Valter Lisboa; Barros, Flavia Alencar; Penido, Norma de Oliveira; Souza, Ana Claudia Valerio de; Yamaoka, Wellington Yugo; Yamashita, Helio

2005-01-01

The etiology of sudden deafness can remain undetermined despite extensive investigation. This study addresses the value of magnetic resonance imaging in the analysis of sudden deafness patients.Study Design: transversal cohort.Material And Method: In a prospective study, 49 patients attended at otolaryngology emergency room of Federal University of Sao Paulo - Escola Paulista de Medicina, from April 2001 to May 2003, were submitted to magnetic resonance imaging.Results: Magnetic Resonance abnormalities were seen in 23 (46.9%) patients and revealed two tumors suggestive of meningioma, three vestibular schwannomas, thirteen microangiopathic changes of the brain and five (21.7%) pathological conditions of the labyrinth.Conclusion: Sudden deafness should be approached as a symptom common to different diseases. The presence of cerebellopontine angle tumors in 10.2% of our cases, among other treatable causes, justifies the recommendation of gadolinium-enhanced magnetic resonance use, not only to study the auditory peripheral pathway, but to study the whole auditory pathway including the brain. (author)

The utility of ultrasound and magnetic resonance imaging versus surgery for the characterization of müllerian anomalies in the pediatric and adolescent population.

Science.gov (United States)

Santos, X M; Krishnamurthy, R; Bercaw-Pratt, J L; Dietrich, J E

2012-06-01

To evaluate the utility of transabdominal ultrasound and magnetic resonance imaging in the evaluation of American Society for Reproductive Medicine (†)(ASRM)-classified müllerian anomalies compared to surgical findings in the pediatric and adolescent population. Retrospective chart review. Tertiary academic center. Thirty-eight patients with müllerian anomalies seen in our pediatric and adolescent gynecology clinic were identified both on the basis of ICD-9 codes and having magnetic resonance imaging at Texas Children's Hospital between 2004 and 2009. None. Correlation among transabdominal ultrasound and magnetic resonance imaging findings with surgical findings. Mean age was 12.2 (± 4.1) years. Twenty-eight patients underwent magnetic resonance imaging and required surgical intervention, and 88.5% demonstrated correlative consistency with surgical findings. Twenty-two patients underwent ultrasound, magnetic resonance imaging, and surgery, which revealed consistency among ultrasound and surgical findings (59.1%) and consistency among magnetic resonance imaging and surgical findings (90.9%). In ASRM diagnoses evaluated by magnetic resonance imaging, surgical findings correlated in 92% (Pearson 0.89). Overall, 55.2% of patients had a renal malformation. Magnetic resonance imaging is the gold standard imaging modality for müllerian anomalies and is an effective technique for noninvasive evaluation and accurate classification of the type of anomaly in the pediatric and adolescent population. Magnetic resonance imaging should be considered as an adjunct to transabdominal ultrasound to evaluate müllerian anomalies. Copyright © 2012 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

Magnetic Resonance Imaging (MRI): Brain (For Parents)

Science.gov (United States)

... Staying Safe Videos for Educators Search English Español Magnetic Resonance Imaging (MRI): Brain KidsHealth / For Parents / Magnetic Resonance Imaging (MRI): Brain What's in this article? What ...

Magnetic resonance signal moment determination using the Earth's magnetic field

KAUST Repository

Fridjonsson, Einar Orn; Creber, Sarah A.; Vrouwenvelder, Johannes S.; Johns, Michael L.

2015-01-01

We demonstrate a method to manipulate magnetic resonance data such that the moments of the signal spatial distribution are readily accessible. Usually, magnetic resonance imaging relies on data acquired in so-called k-space which is subsequently Fourier transformed to render an image. Here, via analysis of the complex signal in the vicinity of the centre of k-space we are able to access the first three moments of the signal spatial distribution, ultimately in multiple directions. This is demonstrated for biofouling of a reverse osmosis (RO) membrane module, rendering unique information and an early warning of the onset of fouling. The analysis is particularly applicable for the use of mobile magnetic resonance spectrometers; here we demonstrate it using an Earth's magnetic field system.

Magnetic resonance signal moment determination using the Earth's magnetic field

KAUST Repository

Fridjonsson, Einar Orn

2015-03-01

We demonstrate a method to manipulate magnetic resonance data such that the moments of the signal spatial distribution are readily accessible. Usually, magnetic resonance imaging relies on data acquired in so-called k-space which is subsequently Fourier transformed to render an image. Here, via analysis of the complex signal in the vicinity of the centre of k-space we are able to access the first three moments of the signal spatial distribution, ultimately in multiple directions. This is demonstrated for biofouling of a reverse osmosis (RO) membrane module, rendering unique information and an early warning of the onset of fouling. The analysis is particularly applicable for the use of mobile magnetic resonance spectrometers; here we demonstrate it using an Earth\\'s magnetic field system.

Cardiac magnetic resonance imaging in Alström syndrome

Directory of Open Access Journals (Sweden)

Carey Catherine M

2009-06-01

Full Text Available Abstract Background A case series of the cardiac magnetic resonance imaging findings in seven adult Alström patients. Methods Seven patients from the National Specialist Commissioning Group Centre for Alström Disease, Torbay, England, UK, completed the cardiac magnetic resonance imaging protocol to assess cardiac structure and function in Alström cardiomyopathy. Results All patients had some degree of left and right ventricular dysfunction. Patchy mid wall gadolinium delayed enhancement was demonstrated, suggesting an underlying fibrotic process. Some degree of cardiomyopathy was universal. No evidence of myocardial infarction or fatty infiltration was demonstrated, but coronary artery disease cannot be completely excluded. Repeat scanning after 18 months in one subject showed progression of fibrosis and decreased left ventricular function. Conclusion Adult Alström cardiomyopathy appears to be a fibrotic process causing impairment of both ventricles. Serial cardiac magnetic resonance scanning has helped clarify the underlying disease progression and responses to treatment. Confirmation of significant mutations in the ALMS1 gene should lead to advice to screen the subject for cardiomyopathy, and metabolic disorders.

Magnetic Resonance Imaging. Chapter 15

Energy Technology Data Exchange (ETDEWEB)

Leach, M. O. [The Institute of Cancer Research and The Royal Marsden Hospital, London (United Kingdom)

2014-09-15

In Chapter 14, the principles of nuclear magnetic resonance were presented, along with an introduction to image forming processes. In this chapter, magnetic resonance imaging (MRI) will be reviewed, beginning with the hardware needed and its impact on image quality. The acquisition processes and image reconstruction will be discussed, as well as the artefacts that are possible, with discussion of the important area of safety and bioeffects completing the chapter.

Force detection of nuclear magnetic resonance

International Nuclear Information System (INIS)

Rugar, D.; Zueger, O.; Hoen, S.; Yannoni, C.S.; Vieth, H.M.; Kendrick, R.D.

1994-01-01

Micromechanical sensing of magnetic force was used to detect nuclear magnetic resonance with exceptional sensitivity and spatial resolution. With a 900 angstrom thick silicon nitride cantilever capable of detecting subfemtonewton forces, a single shot sensitivity of 1.6 x 10 13 protons was achieved for an ammonium nitrate sample mounted on the cantilever. A nearby millimeter-size iron particle produced a 600 tesla per meter magnetic field gradient, resulting in a spatial resolution of 2.6 micrometers in one dimension. These results suggest that magnetic force sensing is a viable approach for enhancing the sensitivity and spatial resolution of nuclear magnetic resonance microimaging

Abnormal pulmonary vein drainage in upper right lobe associated with double aortic arch : magnetic resonance angiography

International Nuclear Information System (INIS)

Busto, M.; Dolz, J.L.; Capdevilla, A.; Castanon, M.; Mulet, J.

1997-01-01

We present the magnetic resonance (MR) and magnetic resonance angiography (MRA) findings in a case of abnormal pulmonary vein drainage from upper right lobe to superior vena cava, associated with double aortic arch, in a six-month-old boy. (Author) 9 refs

Principles of magnetic resonance imaging

International Nuclear Information System (INIS)

Mlynarik, V.; Tkac, I.; Srbecky, M.

1995-01-01

The aim of this review is to describe and explain the basic principles of magnetic resonance imaging. The first part of the text is devoted to the phenomenon of magnetic resonance (the interaction of RF magnetic field with the set of magnetic moments in the homogeneous magnetic field) and to relaxation processes. Then, the creation of MR image is described (slice selection, phase and frequency encoding of spatial information). The basic and the most frequently used techniques are explained (spin echo, gradient echo). The way the repetition and echo times influence the image quality and contrast (T1 or T2 weighing) is described. The part with the technical description of the MR equipment is included in the review. The MR imagination examination are compared with X-ray computer tomography technique

Nuclear magnetic resonance method and apparatus

International Nuclear Information System (INIS)

Burl, M.; Young, I.R.

1984-01-01

A method and apparatus for determining the rate of flow of a liquid in a selected region of a body by nuclear magnetic resonance techniques are described. The method includes a sequence of applying a first magnetic pulse effective to excite nuclear magnetic resonance of a chosen nucleus within the liquid preferentially in a slice of the body which includes the selected region. A period of time (tsub(D)) is waited and then a second magnetic pulse is applied which is effective to excite nuclear magnetic resonance of the nuclei preferentially in the slice, and the free induction decay signal is measured. The whole sequence is repeated for different values of the period of time (tsub(D)). The variation in the value of the measured signal with tsub(D) is then related to the rate of flow of the liquid through the slice. (author)

Caroli's disease: magnetic resonance imaging features

Energy Technology Data Exchange (ETDEWEB)

Guy, France; Cognet, Francois; Dranssart, Marie; Cercueil, Jean-Pierre; Conciatori, Laurent; Krause, Denis [Department of Radiology and Imaging, Dijon Le Bocage University Hospital, 2 Blvd. Marechal de Lattre de Tassigny, BP 1542, 21034 Dijon Cedex (France)

2002-11-01

Our objective was to describe the main aspects of MR imaging in Caroli's disease. Magnetic resonance cholangiography with a dynamic contrast-enhanced study was performed in nine patients with Caroli's disease. Bile duct abnormalities, lithiasis, dot signs, hepatic enhancement, renal abnormalities, and evidence of portal hypertension were evaluated. Three MR imaging patterns of Caroli's disease were found. In all but two patients, MR imaging findings were sufficient to confirm the diagnosis. Moreover, MR imaging provided information about the severity, location, and extent of liver involvement. This information was useful in planning the best therapeutic strategy. Magnetic resonance cholangiography with a dynamic contrast-enhanced study is a good screening tool for Caroli's disease. Direct cholangiography should be reserved for confirming doubtful cases. (orig.)

Advances in magnetic resonance 3

CERN Document Server

Waugh, John S

2013-01-01

Advances in Magnetic Resonance, Volume 3, describes a number of important developments which are finding increasing application by chemists. The book contains five chapters and begins with a discussion of how the properties of random molecular rotations reflect themselves in NMR and how they show up, often differently, in other kinds of experiments. This is followed by separate chapters on the Kubo method, showing its equivalence to the Redfield approach in the cases of most general interest; the current state of dynamic nuclear polarization measurements in solutions and what they tell us abou

Interaction of magnetic resonators studied by the magnetic field enhancement

Directory of Open Access Journals (Sweden)

Yumin Hou

2013-12-01

Full Text Available It is the first time that the magnetic field enhancement (MFE is used to study the interaction of magnetic resonators (MRs, which is more sensitive than previous parameters–shift and damping of resonance frequency. To avoid the coherence of lattice and the effect of Bloch wave, the interaction is simulated between two MRs with same primary phase when the distance is changed in the range of several resonance wavelengths, which is also compared with periodic structure. The calculated MFE oscillating and decaying with distance with the period equal to resonance wavelength directly shows the retardation effect. Simulation also shows that the interaction at normal incidence is sensitive to the phase correlation which is related with retardation effect and is ultra-long-distance interaction when the two MRs are strongly localized. When the distance is very short, the amplitude of magnetic resonance is oppressed by the strong interaction and thus the MFE can be much lower than that of single MR. This study provides the design rules of metamaterials for engineering resonant properties of MRs.

Nuclear Magnetic Resonance Spectroscopy

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 9; Issue 1. Nuclear Magnetic Resonance Spectroscopy. Susanta Das. General Article Volume 9 Issue 1 January 2004 pp 34-49. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/009/01/0034-0049. Keywords.

Magnetic resonance imaging of the fetal brain.

Science.gov (United States)

Tee, L Mf; Kan, E Yl; Cheung, J Cy; Leung, W C

2016-06-01

This review covers the recent literature on fetal brain magnetic resonance imaging, with emphasis on techniques, advances, common indications, and safety. We conducted a search of MEDLINE for articles published after 2010. The search terms used were "(fetal OR foetal OR fetus OR foetus) AND (MR OR MRI OR [magnetic resonance]) AND (brain OR cerebral)". Consensus statements from major authorities were also included. As a result, 44 relevant articles were included and formed the basis of this review. One major challenge is fetal motion that is largely overcome by ultra-fast sequences. Currently, single-shot fast spin-echo T2-weighted imaging remains the mainstay for motion resistance and anatomical delineation. Recently, a snap-shot inversion recovery sequence has enabled robust T1-weighted images to be obtained, which is previously a challenge for standard gradient-echo acquisitions. Fetal diffusion-weighted imaging, diffusion tensor imaging, and magnetic resonance spectroscopy are also being developed. With multiplanar capabilities, superior contrast resolution and field of view, magnetic resonance imaging does not have the limitations of sonography, and can provide additional important information. Common indications include ventriculomegaly, callosum and posterior fossa abnormalities, and twin complications. There are safety concerns about magnetic resonance-induced heating and acoustic damage but current literature showed no conclusive evidence of deleterious fetal effects. The American College of Radiology guideline states that pregnant patients can be accepted to undergo magnetic resonance imaging at any stage of pregnancy if risk-benefit ratio to patients warrants that the study be performed. Magnetic resonance imaging of the fetal brain is a safe and powerful adjunct to sonography in prenatal diagnosis. It can provide additional information that aids clinical management, prognostication, and counselling.

NMR magnetic field controller for pulsed nuclear magnetic resonance experiments

International Nuclear Information System (INIS)

Scheler, G.; Anacker, M.

1975-01-01

A nuclear magnetic resonance controller for magnetic fields, which can also be used for pulsed NMR investigations, is described. A longtime stability of 10 -7 is achieved. The control signal is generated by a modified time sharing circuit with resonance at the first side band of the 2 H signal. An exact calibration of the magnetic field is achieved by the variation of the H 1 - or of the time-sharing frequency. (author)

Resonance of magnetization excited by voltage in magnetoelectric heterostructures

Science.gov (United States)

Yu, Guoliang; Zhang, Huaiwu; Li, Yuanxun; Li, Jie; Zhang, Dainan; Sun, Nian

2018-04-01

Manipulation of magnetization dynamics is critical for spin-based devices. Voltage driven magnetization resonance is promising for realizing low-power information processing systems. Here, we show through Finite Element Method (FEM) simulations that magnetization resonance in nanoscale magnetic elements can be generated by a radio frequency (rf) voltage via the converse magnetoelectric (ME) effect. The magnetization dynamics induced by voltage in a ME heterostructures is simulated by taking into account the magnetoelastic and piezoelectric coupling mechanisms among magnetization, strain and voltage. The frequency of the excited magnetization resonance is equal to the driving rf voltage frequency. The proposed voltage driven magnetization resonance excitation mechanism opens a way toward energy-efficient spin based device applications.

Laser magnetic resonance spectroscopy

International Nuclear Information System (INIS)

Ferrari, C.A.

1985-01-01

The technique of laser resonance magnetic resonance allows one to study the high-resolution spectroscopy of transient paramagnetic species, viz, atoms, radicals, and molecular ions. This article is a brief exposition of the method, describing the principles, instrumentation and applicability of the IR and FIR-LMR and shows results of HF + . (Author) [pt

Magnetic resonance imaging findings after rectus femoris transfer surgery

International Nuclear Information System (INIS)

Gold, Garry E.; Asakawa, Deanna S.; Blemker, Silvia S.; Delp, Scott L.

2004-01-01

We describe the magnetic resonance (MR) imaging appearance of the knee flexor and extensor tendons after bilateral rectus femoris transfer and hamstring lengthening surgery in five patients (10 limbs) with cerebral palsy. Three-dimensional models of the path of the transferred tendon were constructed in all cases. MR images of the transferred and lengthened tendons were examined and compared with images from ten non-surgical subjects. The models showed that the path of the transferred rectus femoris tendon had a marked angular deviation near the transfer site in all cases. MR imaging demonstrated irregular areas of low signal intensity near the transferred rectus femoris and around the hamstrings in all subjects. Eight of the ten post-surgical limbs showed evidence of fluid near or around the transferred or lengthened tendons. This was not observed in the non-surgical subjects. Thus, MR imaging of patients with cerebral palsy after rectus femoris transfer and hamstring-lengthening surgery shows evidence of signal intensity and contour changes, even several years after surgery. (orig.)

Waveguide volume probe for magnetic resonance imaging and spectroscopy

DEFF Research Database (Denmark)

2015-01-01

The present disclosure relates to a probe for use within the field of nuclear magnetic resonance, such as magnetic resonance imaging (MRI), and magnetic resonance spectroscopy (MRS)). One embodiment relates to an RF probe for magnetic resonance imaging and/or spectroscopy comprising a conductive...... non-magnetic hollow waveguide having an internal volume and at least one open end, one or more capacitors and at least a first conductive non-magnetic wire, wherein said first conductive wire connects at least one of said one or more capacitors to opposite walls of one open end of the waveguide...

Presurgical mapping with magnetic source imaging. Comparisons with intraoperative findings

International Nuclear Information System (INIS)

Roberts, T.P.L.; Ferrari, P.; Perry, D.; Rowley, H.A.; Berger, M.S.

2000-01-01

We compare noninvasive preoperative mapping with magnetic source imaging to intraoperative cortical stimulation mapping. These techniques were directly compared in 17 patients who underwent preoperative and postoperative somatosensory mapping of a total of 22 comparable anatomic sites (digits, face). Our findings are presented in the context of previous studies that used magnetic source imaging and functional magnetic resonance imaging as noninvasive surrogates of intraoperative mapping for the identification of sensorimotor and language-specific brain functional centers in patients with brain tumors. We found that magnetic source imaging results were reasonably concordant with intraoperative mapping findings in over 90% of cases, and that concordance could be defined as 'good' in 77% of cases. Magnetic source imaging therefore provides a viable, if coarse, identification of somatosensory areas and, consequently, can guide and reduce the time taken for intraoperative mapping procedures. (author)

Observation of ferromagnetic resonance in a microscopic sample using magnetic resonance force microscopy

International Nuclear Information System (INIS)

Zhang, Z.; Hammel, P.C.; Wigen, P.E.

1996-01-01

We report the observation of a ferromagnetic resonance signal arising from a microscopic (∼20μmx40μm) particle of thin (3μm) yttrium iron garnet film using magnetic resonance force microscopy (MRFM). The large signal intensity in the resonance spectra suggests that MRFM could become a powerful microscopic ferromagnetic resonance technique with a micron or sub-micron resolution. We also observe a very strong nonresonance signal which occurs in the field regime where the sample magnetization readily reorients in response to the modulation of the magnetic field. This signal will be the main noise source in applications where a magnet is mounted on the cantilever. copyright 1996 American Institute of Physics

76 FR 58281 - Magnetic Resonance Imaging Safety; Public Workshop

Science.gov (United States)

2011-09-20

...] Magnetic Resonance Imaging Safety; Public Workshop AGENCY: Food and Drug Administration, HHS. ACTION... announcing a public workshop entitled: ``Magnetic Resonance Imaging (MRI) Safety Public Workshop.'' The purpose of the public workshop is to discuss factors affecting the safe use of magnetic resonance imaging...

Functional magnetic resonance imaging of the primary motor cortex ...

Indian Academy of Sciences (India)

Unknown

Abbreviations used: BOLD, Blood oxygenation level dependent; CBF, cerebral blood flow; fMRI, functional magnetic resonance imaging; EPI, eco-planar imaging; FOV, field of view; MRI, Magnetic resonance imaging; MRS, magnetic resonance spectroscopy;. PET, position emission tomography; rCBF, regional cerebral ...

Magnetic resonance angiography for the head and neck region

International Nuclear Information System (INIS)

Aschenbach, R.; Esser, D.

2004-01-01

Magnetic resonance angiography is a noninvasive method in vascular imaging using noncontrast- enhanced and contrast-enhanced techniques. The contrast media used in contrast- enhanced magnetic resonance angiography are different from the X-ray contrast media and do not affect the thyroid gland or renal function. In detecting hypervascularized lesions in the head and neck, contrast-enhanced magnetic resonance angiography is the method of choice, which provides an acceptable quality in comparison to digital subtraction angiography. Future developments in magnetic resonance imaging techniques will cause a wider use of magnetic resonance angiography, especially in head and neck imaging. Digital subtraction angiography should therefore only be used in problem cases and for preoperative embolization [de

Magnetic resonance imaging in deep pelvic endometriosis: iconographic essay

International Nuclear Information System (INIS)

Coutinho Junior, Antonio Carlos; Coutinho, Elisa Pompeu Dias; Lima, Claudio Marcio Amaral de Oliveira; Ribeiro, Erica Barreiros; Aidar, Marisa Nassar; Gasparetto, Emerson Leandro

2008-01-01

Endometriosis is characterized by the presence of normal endometrial tissue outside the uterine cavity. In patients with deep pelvic endometriosis, uterosacral ligaments, rectum, rectovaginal septum, vagina or bladder may be involved. Clinical manifestations may be variable, including pelvic pain, dysmenorrhea, dyspareunia, urinary symptoms and infertility. Complete surgical excision is the gold standard for treating this disease, and hence the importance of the preoperative work-up that usually is limited to an evaluation of sonographic and clinical data. Magnetic resonance imaging is of paramount importance in the diagnosis of endometriosis, considering its high accuracy in the identification of lesions intermingled with adhesions, and in the determination of peritoneal lesions extent. The present pictorial review describes the main magnetic resonance imaging findings in deep pelvic endometriosis. (author)

Magnetic resonance imaging in deep pelvic endometriosis: iconographic essay

Energy Technology Data Exchange (ETDEWEB)

Coutinho Junior, Antonio Carlos; Coutinho, Elisa Pompeu Dias; Lima, Claudio Marcio Amaral de Oliveira; Ribeiro, Erica Barreiros; Aidar, Marisa Nassar [Clinica de Diagnostico por Imagem (CDPI), Rio de Janeiro, RJ (Brazil); Clinica Multi-Imagem, Rio de Janeiro, RJ (Brazil); E-mail: cmaol@br.inter.net; Gasparetto, Emerson Leandro [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Dept. de Radiologia

2008-03-15

Endometriosis is characterized by the presence of normal endometrial tissue outside the uterine cavity. In patients with deep pelvic endometriosis, uterosacral ligaments, rectum, rectovaginal septum, vagina or bladder may be involved. Clinical manifestations may be variable, including pelvic pain, dysmenorrhea, dyspareunia, urinary symptoms and infertility. Complete surgical excision is the gold standard for treating this disease, and hence the importance of the preoperative work-up that usually is limited to an evaluation of sonographic and clinical data. Magnetic resonance imaging is of paramount importance in the diagnosis of endometriosis, considering its high accuracy in the identification of lesions intermingled with adhesions, and in the determination of peritoneal lesions extent. The present pictorial review describes the main magnetic resonance imaging findings in deep pelvic endometriosis. (author)

Agreement between computed tomography, magnetic resonance imaging, and surgical findings in dogs with degenerative lumbosacral stenosis.

Science.gov (United States)

Suwankong, Niyada; Voorhout, George; Hazewinkel, Herman A W; Meij, Björn P

2006-12-15

To assess the extent of agreement between computed tomography (CT), magnetic resonance imaging (MRI), and surgical findings in dogs with degenerative lumbosacral stenosis. Observational study. 35 dogs with degenerative lumbosacral stenosis. Results of preoperative CT and MRI were compared with surgical findings with respect to degree and location of disk protrusion, position of the dural sac, amount of epidural fat, and swelling of spinal nerve roots. A lumbosacral step was seen on radiographic images from 22 of 32 (69%) dogs, on CT images from 23 of 35 (66%) dogs, and on MR images from 21 of 35 (60%) dogs. Most dogs had slight or moderate disk protrusion that was centrally located. There was substantial or near perfect agreement between CT and MRI findings in regard to degree of disk protrusion (kappa, 0.88), location of disk protrusion (0.63), position of the dural sac (0.89), amount of epidural fat (0.72), and swelling of spinal nerve roots (0.60). The degree of agreement between CT and surgical findings and between MRI and surgical findings was moderate in regard to degree and location of disk protrusion (kappa, 0.44 to 0.56) and swelling of spinal nerve roots (0.40 and 0.50). Results indicate that there is a high degree of agreement between CT and MRI findings in dogs with degenerative lumbosacral stenosis but that the degree of agreement between diagnostic imaging findings and surgical findings is lower.

Magnetic resonance findings of the corpus callosum in canine and feline lysosomal storage diseases.

Science.gov (United States)

Hasegawa, Daisuke; Tamura, Shinji; Nakamoto, Yuya; Matsuki, Naoaki; Takahashi, Kimimasa; Fujita, Michio; Uchida, Kazuyuki; Yamato, Osamu

2013-01-01

Several reports have described magnetic resonance (MR) findings in canine and feline lysosomal storage diseases such as gangliosidoses and neuronal ceroid lipofuscinosis. Although most of those studies described the signal intensities of white matter in the cerebrum, findings of the corpus callosum were not described in detail. A retrospective study was conducted on MR findings of the corpus callosum as well as the rostral commissure and the fornix in 18 cases of canine and feline lysosomal storage diseases. This included 6 Shiba Inu dogs and 2 domestic shorthair cats with GM1 gangliosidosis; 2 domestic shorthair cats, 2 familial toy poodles, and a golden retriever with GM2 gangliosidosis; and 2 border collies and 3 chihuahuas with neuronal ceroid lipofuscinoses, to determine whether changes of the corpus callosum is an imaging indicator of those diseases. The corpus callosum and the rostral commissure were difficult to recognize in all cases of juvenile-onset gangliosidoses (GM1 gangliosidosis in Shiba Inu dogs and domestic shorthair cats and GM2 gangliosidosis in domestic shorthair cats) and GM2 gangliosidosis in toy poodles with late juvenile-onset. In contrast, the corpus callosum and the rostral commissure were confirmed in cases of GM2 gangliosidosis in a golden retriever and canine neuronal ceroid lipofuscinoses with late juvenile- to early adult-onset, but were extremely thin. Abnormal findings of the corpus callosum on midline sagittal images may be a useful imaging indicator for suspecting lysosomal storage diseases, especially hypoplasia (underdevelopment) of the corpus callosum in juvenile-onset gangliosidoses.

Magnetic resonance findings of the corpus callosum in canine and feline lysosomal storage diseases.

Directory of Open Access Journals (Sweden)

Daisuke Hasegawa

Full Text Available Several reports have described magnetic resonance (MR findings in canine and feline lysosomal storage diseases such as gangliosidoses and neuronal ceroid lipofuscinosis. Although most of those studies described the signal intensities of white matter in the cerebrum, findings of the corpus callosum were not described in detail. A retrospective study was conducted on MR findings of the corpus callosum as well as the rostral commissure and the fornix in 18 cases of canine and feline lysosomal storage diseases. This included 6 Shiba Inu dogs and 2 domestic shorthair cats with GM1 gangliosidosis; 2 domestic shorthair cats, 2 familial toy poodles, and a golden retriever with GM2 gangliosidosis; and 2 border collies and 3 chihuahuas with neuronal ceroid lipofuscinoses, to determine whether changes of the corpus callosum is an imaging indicator of those diseases. The corpus callosum and the rostral commissure were difficult to recognize in all cases of juvenile-onset gangliosidoses (GM1 gangliosidosis in Shiba Inu dogs and domestic shorthair cats and GM2 gangliosidosis in domestic shorthair cats and GM2 gangliosidosis in toy poodles with late juvenile-onset. In contrast, the corpus callosum and the rostral commissure were confirmed in cases of GM2 gangliosidosis in a golden retriever and canine neuronal ceroid lipofuscinoses with late juvenile- to early adult-onset, but were extremely thin. Abnormal findings of the corpus callosum on midline sagittal images may be a useful imaging indicator for suspecting lysosomal storage diseases, especially hypoplasia (underdevelopment of the corpus callosum in juvenile-onset gangliosidoses.

Imaging of plantar fascia disorders: findings on plain radiography, ultrasound and magnetic resonance imaging.

Science.gov (United States)

Draghi, Ferdinando; Gitto, Salvatore; Bortolotto, Chandra; Draghi, Anna Guja; Ori Belometti, Gioia

2017-02-01

Plantar fascia (PF) disorders commonly cause heel pain and disability in the general population. Imaging is often required to confirm diagnosis. This review article aims to provide simple and systematic guidelines for imaging assessment of PF disease, focussing on key findings detectable on plain radiography, ultrasound and magnetic resonance imaging (MRI). Sonographic characteristics of plantar fasciitis include PF thickening, loss of fibrillar structure, perifascial collections, calcifications and hyperaemia on Doppler imaging. Thickening and signal changes in the PF as well as oedema of adjacent soft tissues and bone marrow can be assessed on MRI. Radiographic findings of plantar fasciitis include PF thickening, cortical irregularities and abnormalities in the fat pad located deep below the PF. Plantar fibromatosis appears as well-demarcated, nodular thickenings that are iso-hypoechoic on ultrasound and show low-signal intensity on MRI. PF tears present with partial or complete fibre interruption on both ultrasound and MRI. Imaging description of further PF disorders, including xanthoma, diabetic fascial disease, foreign-body reactions and plantar infections, is detailed in the main text. Ultrasound and MRI should be considered as first- and second-line modalities for assessment of PF disorders, respectively. Indirect findings of PF disease can be ruled out on plain radiography. Teaching Points • PF disorders commonly cause heel pain and disability in the general population.• Imaging is often required to confirm diagnosis or reveal concomitant injuries.• Ultrasound and MRI respectively represent the first- and second-line modalities for diagnosis.• Indirect findings of PF disease can be ruled out on plain radiography.

Magnetic Resonance Findings of the Corpus Callosum in Canine and Feline Lysosomal Storage Diseases

Science.gov (United States)

Hasegawa, Daisuke; Tamura, Shinji; Nakamoto, Yuya; Matsuki, Naoaki; Takahashi, Kimimasa; Fujita, Michio; Uchida, Kazuyuki; Yamato, Osamu

2013-01-01

Several reports have described magnetic resonance (MR) findings in canine and feline lysosomal storage diseases such as gangliosidoses and neuronal ceroid lipofuscinosis. Although most of those studies described the signal intensities of white matter in the cerebrum, findings of the corpus callosum were not described in detail. A retrospective study was conducted on MR findings of the corpus callosum as well as the rostral commissure and the fornix in 18 cases of canine and feline lysosomal storage diseases. This included 6 Shiba Inu dogs and 2 domestic shorthair cats with GM1 gangliosidosis; 2 domestic shorthair cats, 2 familial toy poodles, and a golden retriever with GM2 gangliosidosis; and 2 border collies and 3 chihuahuas with neuronal ceroid lipofuscinoses, to determine whether changes of the corpus callosum is an imaging indicator of those diseases. The corpus callosum and the rostral commissure were difficult to recognize in all cases of juvenile-onset gangliosidoses (GM1 gangliosidosis in Shiba Inu dogs and domestic shorthair cats and GM2 gangliosidosis in domestic shorthair cats) and GM2 gangliosidosis in toy poodles with late juvenile-onset. In contrast, the corpus callosum and the rostral commissure were confirmed in cases of GM2 gangliosidosis in a golden retriever and canine neuronal ceroid lipofuscinoses with late juvenile- to early adult-onset, but were extremely thin. Abnormal findings of the corpus callosum on midline sagittal images may be a useful imaging indicator for suspecting lysosomal storage diseases, especially hypoplasia (underdevelopment) of the corpus callosum in juvenile-onset gangliosidoses. PMID:24386203

Single voxel magnetic resonance spectroscopy in distinguishing ...

African Journals Online (AJOL)

Objective: Assess diagnostic utility of combined magnetic resonance imaging and magnetic resonance spectroscopy (MRI, MRS) in differentiating focal neoplastic lesions from focal non- neoplastic (infective or degenerative) brain lesions. Design: Descriptive, analytical - prospective study. Setting: The Aga Khan University ...

Your Radiologist Explains Magnetic Resonance Angiography (MRA)

Medline Plus

Full Text Available ... Sponsored by Image/Video Gallery Your Radiologist Explains Magnetic Resonance Angiography (MRA) Transcript Welcome to Radiology Info dot ... I’d like to talk with you about magnetic resonance angiography, or as it’s commonly known, MRA. MRA ...

Magnetic resonance imaging in MELAS syndrome

International Nuclear Information System (INIS)

Rosen, L.; Phillips, S.; Enzmann, D.

1990-01-01

MELAS syndrome is a distinct clinical entity belonging to a group of mitochondrial encephalomyopathies characterized by the tetrad of myopathy, encephalopathy, lactic acidosis, and stroke-like episodes. Computed tomography (CT) and magnetic resonance (MR) findings are reviewed in a patient with MELAS. Serial CT studies demonstrated multiple 'migrating' infarcts in various stages of evolution involving primarily the posterior temporal and occipital regions. MR was more sensitive than CT in demonstrating the number and extent of cortical lesions in this disease entity. (orig.)

Comparative magnetic resonance imaging findings between gliomas and presumed cerebrovascular accidents in dogs.

Science.gov (United States)

Cervera, Vicente; Mai, Wilfried; Vite, Charles H; Johnson, Victoria; Dayrell-Hart, Betsy; Seiler, Gabriela S

2011-01-01

Cerebrovascular accidents, or strokes, and gliomas are common intraaxial brain lesions in dogs. An accurate differentiation of these two lesions is necessary for prognosis and treatment decisions. The magnetic resonance (MR) imaging characteristics of 21 dogs with a presumed cerebrovascular accident and 17 with a glioma were compared. MR imaging findings were reviewed retrospectively by three observers unaware of the final diagnosis. Statistically significant differences between the appearance of gliomas and cerebrovascular accidents were identified based on lesion location, size, mass effect, perilesional edema, and appearance of the apparent diffusion coefficient map. Gliomas were predominantly located in the cerebrum (76%) compared with presumed cerebrovascular accidents that were located mainly in the cerebellum, thalamus, caudate nucleus, midbrain, and brainstem (76%). Gliomas were significantly larger compared with presumed cerebrovascular accidents and more commonly associated with mass effect and perilesional edema. Wedge-shaped lesions were seen only in 19% of presumed cerebrovascular accidents. Between the three observers, 10-47% of the presumed cerebrovascular accidents were misdiagnosed as gliomas, and 0-12% of the gliomas were misdiagnosed as cerebrovascular accidents. Diffusion weighted imaging increased the accuracy of the diagnosis for both lesions. Agreement between observers was moderate (kappa = 0.48, P < 0.01).

Magnetic resonance imaging of Parkinsonism

International Nuclear Information System (INIS)

Mukai, Eiichiro; Makino, Naoki; Fujishiro, Kenichiro.

1989-01-01

We have analyzed magnetic resonance images in 33 patients; 18 patients with Parkinson's disease, 1 patient with diurnally fluctuating progressive dystonia, 1 patient with pure akinesia, 6 patients with multiple system atrophy, 1 patient with flunarizine induced parkinsonism, and 4 patients with unclassified parkinsonism. The MR images were obtained using a 1.5-T GE MR System. A spin-echo pulse sequence was used with a TE of 30 msec and 80 msec and a TR of 2000 msec. No signal abnormalities were seen in any patient with Parkinson's disease but 3 showed slightly decreased signal intensity of the putamen on T2-weighted sequences. Patients with diurnally fluctuating progressive dystonia and pure akinesia evidensed no abnormal findings. All six patients with multiple system atrophy demonstrated decreased signal intensity of the putamen, particularly along their lateral and posterior portions, and an enlarged substantia nigra. Atrophy of the pons and cerebellum was detected in all cases with multiple system atrophy. One case of flunarizine induced parkinsonism showed slightly decreased signal intensity of the putamen. Four cases of unclassified parkinsonism showed decreased signal in the putamen on T2-weighted sequences. Magnetic resonance imaging has the potential to become a useful diagnostic tool in the management of parkinsonism. (author)

Magnetic resonance imaging of Parkinsonism

Energy Technology Data Exchange (ETDEWEB)

Mukai, Eiichiro [National Hospital of Nagoya (Japan); Makino, Naoki; Fujishiro, Kenichiro

1989-06-01

We have analyzed magnetic resonance images in 33 patients; 18 patients with Parkinson's disease, 1 patient with diurnally fluctuating progressive dystonia, 1 patient with pure akinesia, 6 patients with multiple system atrophy, 1 patient with flunarizine induced parkinsonism, and 4 patients with unclassified parkinsonism. The MR images were obtained using a 1.5-T GE MR System. A spin-echo pulse sequence was used with a TE of 30 msec and 80 msec and a TR of 2000 msec. No signal abnormalities were seen in any patient with Parkinson's disease but 3 showed slightly decreased signal intensity of the putamen on T2-weighted sequences. Patients with diurnally fluctuating progressive dystonia and pure akinesia evidensed no abnormal findings. All six patients with multiple system atrophy demonstrated decreased signal intensity of the putamen, particularly along their lateral and posterior portions, and an enlarged substantia nigra. Atrophy of the pons and cerebellum was detected in all cases with multiple system atrophy. One case of flunarizine induced parkinsonism showed slightly decreased signal intensity of the putamen. Four cases of unclassified parkinsonism showed decreased signal in the putamen on T2-weighted sequences. Magnetic resonance imaging has the potential to become a useful diagnostic tool in the management of parkinsonism. (author).

Anatomical Brain Magnetic Resonance Imaging of Typically Developing Children and Adolescents

Science.gov (United States)

Giedd, Jay N.; Lalonde, Francois M.; Celano, Mark J.; White, Samantha L.; Wallace, Gregory L.; Lee, Nancy R.; Lenroot, Rhoshel K.

2009-01-01

Methodological issues relevant to magnetic resonance imaging studies of brain anatomy are discussed along with the findings on the neuroanatomic changes during childhood and adolescence. The development of the brain is also discussed.

Magnetic resonance imaging of pelvic endometriosis

International Nuclear Information System (INIS)

Vieira, G.P.; Martin, B.; Tubiana, J.M.

1994-01-01

Twenty-five magnetic resonance imaging (MRI) studies were performed in 18 patients with proven endometriosis. MRI findings were analyzed and compared with laparoscopic or surgical findings; MRI accurately demonstrated ovarian endometrial cysts as well as ectopic foci of endometriosis. Adhesions may be also suggested. Contrary to laparoscopy, MRI easily depicts both deep lesions and endometrial implants under the peritoneum. Consequently, MRI appears as an useful adjunct to laparoscopy for initial diagnosis before starting a medical treatment and above all as the imaging modality of choice for evaluation of the answer to treatment, avoiding iterative and often adhesions limited laparoscopies. (author). 7 refs.; 9 figs

Contrast agents in magnetic resonance imaging

International Nuclear Information System (INIS)

Karadjian, V.

1987-01-01

The origine of nuclear magnetic resonance signal is reminded and different ways for contrast enhancement in magnetic resonance imaging are presented, especially, modifications of tissus relaxation times. Investigations have focused on development of agents incorporating either paramagnetic ions or stable free radicals. Pharmacological and toxicological aspects are developed. The diagnostic potential of these substances is illustrated by the example of gadolinium complexes [fr

Magnetic resonance: discovery, investigations, and applications

International Nuclear Information System (INIS)

Kessenikh, Aleksandr V

2009-01-01

The history of the development of the theoretical ideas and experimental methods of magnetic resonance, as well as the applications of these methods in modern natural science, technology, and medicine, are outlined, with allowance for the contribution of Russian researchers. An assessment of some promising trends of studies and applications of magnetic resonance is given. (from the history of physics)

Reducing Field Distortion in Magnetic Resonance Imaging

Science.gov (United States)

Eom, Byeong Ho; Penanen, Konstantin; Hahn, Inseob

2010-01-01

A concept for a magnetic resonance imaging (MRI) system that would utilize a relatively weak magnetic field provides for several design features that differ significantly from the corresponding features of conventional MRI systems. Notable among these features are a magnetic-field configuration that reduces (relative to the conventional configuration) distortion and blurring of the image, the use of a superconducting quantum interference device (SQUID) magnetometer as the detector, and an imaging procedure suited for the unconventional field configuration and sensor. In a typical application of MRI, a radio-frequency pulse is used to excite precession of the magnetic moments of protons in an applied magnetic field, and the decaying precession is detected for a short time following the pulse. The precession occurs at a resonance frequency proportional to the strengths of the magnetic field and the proton magnetic moment. The magnetic field is configured to vary with position in a known way; hence, by virtue of the aforesaid proportionality, the resonance frequency varies with position in a known way. In other words, position is encoded as resonance frequency. MRI using magnetic fields weaker than those of conventional MRI offers several advantages, including cheaper and smaller equipment, greater compatibility with metallic objects, and higher image quality because of low susceptibility distortion and enhanced spin-lattice-relaxation- time contrast. SQUID MRI is being developed into a practical MRI method for applied magnetic flux densities of the order of only 100 T

Pulse sequences for contrast-enhanced magnetic resonance imaging

International Nuclear Information System (INIS)

Graves, Martin J.

2007-01-01

The theory and application of magnetic resonance imaging (MRI) pulse sequences following the administration of an exogenous contrast agent are discussed. Pulse sequences are categorised according to the contrast agent mechanism: changes in proton density, relaxivity, magnetic susceptibility and resonant frequency shift. Applications in morphological imaging, magnetic resonance angiography, dynamic imaging and cell labelling are described. The importance of optimising the pulse sequence for each application is emphasised

Magnetic field induced incommensurate resonance in cuprate superconductors

International Nuclear Information System (INIS)

Zhang Jingge; Cheng Li; Guo Huaiming; Feng Shiping

2009-01-01

The influence of a uniform external magnetic field on the dynamical spin response of cuprate superconductors in the superconducting state is studied based on the kinetic energy driven superconducting mechanism. It is shown that the magnetic scattering around low and intermediate energies is dramatically changed with a modest external magnetic field. With increasing the external magnetic field, although the incommensurate magnetic scattering from both low and high energies is rather robust, the commensurate magnetic resonance scattering peak is broadened. The part of the spin excitation dispersion seems to be an hourglass-like dispersion, which breaks down at the heavily low energy regime. The theory also predicts that the commensurate resonance scattering at zero external magnetic field is induced into the incommensurate resonance scattering by applying an external magnetic field large enough

Ultrasound and magnetic resonance imaging findings in Schistosomiasis mansoni: expanded gallbladder fossa and fatty hilum signs

Directory of Open Access Journals (Sweden)

Luciana Cristina dos Santos Silva

2012-08-01

Full Text Available INTRODUCTION: There is no study relating magnetic resonance imaging (MRI to ultrasound (US findings in patients with Schistosomiasis mansoni. Our aim was to describe MRI findings inpatients with schistosomal liver disease identified by US. METHODS: Fifty-four patients (mean age 41.6±13.5years from an area endemic for Schistosomiasis mansoni were selected for this study.All had US indicating liver schistosomal fibrosis and were evaluated with MRI performed witha 1.5-T superconducting magnet unit (Sigma. RESULTS: Forty-seven (87% of the 54 patientsshowing signs of periportal fibrosis identified through US investigation had confirmed diagnosesby MRI. In the seven discordant cases (13%, MRI revealed fat tissue filling in the hilar periportalspace where US indicated isolated thickening around the main portal vein at its point of entryto the liver. We named this the fatty hilum sign. One of the 47 patients with MRI evidence ofperiportal fibrosis had had his gallbladder removed previously. Thirty-five (76.1% of the other46 patients had an expanded gallbladder fossa filled with fat tissue, whereas MRI of the remainingeleven showed pericholecystic signs of fibrosis. CONCLUSIONS: Echogenic thickening of thegallbladder wall and of the main portal vein wall heretofore attributed to fibrosis were frequentlyidentified as fat tissue in MRI. However, the gallbladder wall thickening shown in US (expandedgallbladder fossa in MRI is probably secondary to combined hepatic morphologic changes inschistosomiasis, representing severe liver involvement.

Magnetic resonance imaging- physical principles and clinical application

International Nuclear Information System (INIS)

Tavri, Omprakash J.

1996-01-01

The advances in equipment and knowledge related to radiology are occurring at an astonishingly rapid rate. On November 8, 1895, William Conrad Roentgen discovered x-rays. In 1972, Godfrey Hounsfield and George Ambrose introduced computec tomography at a meeting of the British Institute of Radiology. In the same year, Paul Lauterbur published the idea of spatially resolving nuclear magnetic resonance samples, naming it zeugmatography. In 1977, Waldo Hinshaw and co-workers published a magnetic resonance image of a human hand and wrist, and by 1981 several centres were obtaining clinical magnetic resonance (MR) images. In a very short time, magnetic resonance imaging (MRI) has gained acceptance as a clinically useful imaging tool. (author)

Quantum speed limit time in a magnetic resonance

Science.gov (United States)

Ivanchenko, E. A.

2017-12-01

A visualization for dynamics of a qudit spin vector in a time-dependent magnetic field is realized by means of mapping a solution for a spin vector on the three-dimensional spherical curve (vector hodograph). The obtained results obviously display the quantum interference of precessional and nutational effects on the spin vector in the magnetic resonance. For any spin the bottom bounds of the quantum speed limit time (QSL) are found. It is shown that the bottom bound goes down when using multilevel spin systems. Under certain conditions the non-nil minimal time, which is necessary to achieve the orthogonal state from the initial one, is attained at spin S = 2. An estimation of the product of two and three standard deviations of the spin components are presented. We discuss the dynamics of the mutual uncertainty, conditional uncertainty and conditional variance in terms of spin standard deviations. The study can find practical applications in the magnetic resonance, 3D visualization of computational data and in designing of optimized information processing devices for quantum computation and communication.

Breast Magnetic Resonance Imaging Findings in Women Treated with Toremifene for Premenstrual Mastalgia

International Nuclear Information System (INIS)

Oksa, S.; Parkkola, R.; Luukkaala, T.; Maeenpaeae, J.

2009-01-01

Background: Toremifene, a selective estrogen receptor modulator, has been shown to be effective in alleviating premenstrual breast pain. However, the exact mechanism by which toremifene and related compounds work in premenstrual mastalgia is poorly understood. Purpose: To find out if the effect of toremifene on breast would be detectable with dynamic magnetic resonance imaging (MRI). Material and Methods: This randomized, double-blind crossover study was performed on women suffering from marked premenstrual mastalgia. Ten women were randomized to receive either toremifene (20 mg) or placebo from cycle day 15 until next menstruation for three menstrual cycles. After a washout period, the treatment was crossed over for three additional cycles. The MRI evaluations were performed premenstrually at the end of each treatment phase. Breast pain and quality-of-life scores were collected from one baseline cycle and from all the treatment cycles. Results: Nine patients were evaluable for this analysis. Both the enhancement ratio and the maximum slope of enhancement tended to be smaller during the toremifene cycles as compared to placebo. On the left side, the difference in the maximum slope of enhancement between toremifene and placebo was statistically significant (median 5.150 [range 3.7-6.7] and 6.500 [range 4.9-9.5], respectively; P=0.047). T2 relaxation times as well as breast pain and quality-of-life scores were inconsistent. Conclusion: Use of toremifene is associated with measurable changes in dynamic breast MRI findings in women with cyclic breast pain

Breast Magnetic Resonance Imaging Findings in Women Treated with Toremifene for Premenstrual Mastalgia

Energy Technology Data Exchange (ETDEWEB)

Oksa, S. (Dept. of Obstetrics and Gynecology, Satakunta Central Hospital, Pori (Finland)); Parkkola, R. (Dept. of Radiology, Univ. Hospital of Turku, Turku (Finland)); Luukkaala, T.; Maeenpaeae, J. (Medical School, Univ. of Tampere, Tampere (Finland))

2009-11-15

Background: Toremifene, a selective estrogen receptor modulator, has been shown to be effective in alleviating premenstrual breast pain. However, the exact mechanism by which toremifene and related compounds work in premenstrual mastalgia is poorly understood. Purpose: To find out if the effect of toremifene on breast would be detectable with dynamic magnetic resonance imaging (MRI). Material and Methods: This randomized, double-blind crossover study was performed on women suffering from marked premenstrual mastalgia. Ten women were randomized to receive either toremifene (20 mg) or placebo from cycle day 15 until next menstruation for three menstrual cycles. After a washout period, the treatment was crossed over for three additional cycles. The MRI evaluations were performed premenstrually at the end of each treatment phase. Breast pain and quality-of-life scores were collected from one baseline cycle and from all the treatment cycles. Results: Nine patients were evaluable for this analysis. Both the enhancement ratio and the maximum slope of enhancement tended to be smaller during the toremifene cycles as compared to placebo. On the left side, the difference in the maximum slope of enhancement between toremifene and placebo was statistically significant (median 5.150 [range 3.7-6.7] and 6.500 [range 4.9-9.5], respectively; P=0.047). T2 relaxation times as well as breast pain and quality-of-life scores were inconsistent. Conclusion: Use of toremifene is associated with measurable changes in dynamic breast MRI findings in women with cyclic breast pain

Low field magnetic resonance imaging

Science.gov (United States)

Pines, Alexander; Sakellariou, Dimitrios; Meriles, Carlos A.; Trabesinger, Andreas H.

2010-07-13

A method and system of magnetic resonance imaging does not need a large homogenous field to truncate a gradient field. Spatial information is encoded into the spin magnetization by allowing the magnetization to evolve in a non-truncated gradient field and inducing a set of 180 degree rotations prior to signal acquisition.

Magnetic Resonance Imaging (MRI) -- Head

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Full Text Available ... by the interpreting radiologist. Frequently, the differentiation of abnormal (diseased) tissue from normal tissues is better with ... Tumor Treatment Magnetic Resonance Imaging (MRI) Safety Alzheimer's Disease Head Injury Brain Tumors Images related to Magnetic ...

Cavernous sinus invasion by pituitary adenomas. Relationship between magnetic resonance imaging findings and histologically verified dural invasion

Energy Technology Data Exchange (ETDEWEB)

Daita, Go; Yonemasu, Yukichi; Nakai, Hirofumi; Takei, Hidetoshi; Ogawa, Katsuhiro [Asahikawa Medical Coll., Hokkaido (Japan)

1995-01-01

The relationship between magnetic resonance (MR) imaging findings and histologically verified invasion of the cavernous sinus by tumor cells was studied in 26 patients treated surgically for pituitary adenoma. Dural invasion of the sellar floor by tumor cells was found in 10 cases (38%). All patients were classified according to MR imaging findings into three types. Type I showed a gadolinium-enhanced stripe medial to the carotid artery (5 patients), none of which showed dural invasion. Type II showed no enhanced stripe (17 patients), six of which showed dural invasion. Within this type, tumor size and dural invasion showed no correlation. Type III showed displacement or encasement of the carotid artery by the tumor with or without extracranial extension (4 patients), all of which showed massive infiltration of the tumor cells into the dura mater. This study shows that preoperative MR imaging can provide information for assessment of invasion into the cavernous sinus in patients with pituitary adenoma. (author).

Role of proton magnetic resonance spectroscopy in diagnosis of ...

African Journals Online (AJOL)

Mohammed Mahmoud Donia

2012-01-23

Jan 23, 2012 ... Subjects and methods: This study included seven pediatric patients ... ton magnetic resonance spectroscopy was done using either single or multi-voxel technique. ... with increased NAA/Cr ratio (2.32 ± 1.1). ... Table 1 Summary of the spectroscopic MRI findings in the seven patients included in the study.

Big cat scan: magnetic resonance imaging of the tiger

International Nuclear Information System (INIS)

Snow, Thomas M.; Gregory, Richard J.W.; Litster, Annette L.; Hanger, Jonathan J.

2004-01-01

In August 2002, we performed MRI scans on a female juvenile Bengal tiger. We present the clinical course, imaging and autopsy findings, and some comparative anatomy of the tiger brain and skull. Magnetic resonance images of a tiger have not previously been published Copyright (2004) Blackwell Publishing Asia Pty Ltd

Tuning Coler Magnetic Current Apparatus with Magneto-Acoustic Resonance

Science.gov (United States)

Ludwig, Thorsten

An attempt was made to tune the Coler magnetic current apparatus with the magneto acoustic resonance of the magnetic rods. Measurements with a replica of the famous Coler "Magnetstromapparat" were conducted. In order to tune the acoustic, magnetic and electric resonance circuits of the Coler device the magneto-acoustic resonance was measured with a frequency scan through a function generator and a lock-in amplifier. The frequency generator was powering a driving coil, while the lock-in was connected to a pickup coil. Both coils were placed on a magnetic rod. Resonances were observed up to the 17th harmonic. The quality Q of the observed resonances was 270. To study the magneto-acoustic resonance in the time domain a pair of Permendur rods were employed. The magneto-acoustic resonances of the Permendur rods were observed with an oscilloscope. Spectra of the magneto acoustic resonance were measured for the Permendur rods and for a Coler replica magnet in the frequency range from 25 kHz to 380 kHz. The next step was to bring the resonances of the Permendur rods close together so that they overlap. The 10thharmonic was chosen because it was close to the 180 kHz that Hans Coler related to ferromagnetism. Further more magneto-acoustic coupling between the Permendur rods was studied. Finally the question was explored if Hans Coler converted vacuum fluctuations via magnetic and acoustic resonance into electricity. There is a strong connection between magnetism and quantum field zero point energy (ZPE). An outlook is given on next steps in the experiments to unveil the working mechanism of the Coler magnetic current apparatus.

Rotational characteristics in the resonance state of the HTSC-permanent magnet hybrid magnetic bearing

Energy Technology Data Exchange (ETDEWEB)

Morii, Y.; Sukedai, M. [Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-8680 (Japan); Ohashi, S., E-mail: ohashi@kansai-u.ac.jp [Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-8680 (Japan)

2011-11-15

The hybrid magnetic bearing has been developed. In the hybrid system, effect of the pinning force becomes smaller. Influence of the vibration and the gradient angle in the resonance state is large. The resonance frequency becomes small in the hybrid bearing system. The hybrid magnetic bearing using permanent magnets and the high-Tc bulk superconductor (HTSC) has been developed. Repulsive force of the permanent magnet is introduced to increase the load weight of the magnetic bearing. Effect of the hybrid system has been shown. In this paper, influence of the hybrid system on the dynamic characteristics of the rotor is studied. The rotational characteristics in the mechanical resonance state are studied, and the equivalent magnetic spring coefficient is estimated from the experimental results of the load weight. The resonance frequency is measured by the rotation experiments. The rotor achieves stable levitation even in the resonance state. In the hybrid system, effect of the pinning force becomes smaller than that of the lateral force generated by the repulsive force between the two permanent magnets at the smaller air gap. Thus influence of the lateral vibration and the gradient angle in the resonance state becomes larger at a smaller air gap. The equivalent magnetic spring coefficient becomes also small, and the resonance frequency becomes small in the hybrid bearing system.

Cardiovascular magnetic resonance in congenital heart disease

International Nuclear Information System (INIS)

Cazacu, A.; Ciubotaru, A.

2010-01-01

The increasing prevalence of congenital heart disease can be attributed to major improvements in diagnosis and treatment. Cardiovascular magnetic resonance imaging plays an important role in the clinical management strategy of patients with congenital heart disease. The development of new cardiovascular magnetic resonance (CMR) techniques allows comprehensive assessment of complex cardiac anatomy and function and provides information about the long-term residual post-operative lesions and complications of surgery. It overcomes many of the limitations of echocardiography and cardiac catheterization. This review evaluates the role of cardiovascular magnetic resonance imaging modality in the management of subject with congenital heart disease (CHD). (authors)

Children's (Pediatric) Magnetic Resonance Imaging

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Full Text Available ... Related Articles and Media Catheter Angiography Magnetic Resonance, Functional (fMRI) - Brain Children's (Pediatric) CT (Computed Tomography) Magnetic ... the possible charges you will incur. Web page review process: This Web page is reviewed regularly by ...

Magnetic resonance imaging of the central nervous system

International Nuclear Information System (INIS)

Brant-Zawadzki, M.; Norman, D.

1987-01-01

This book presents the papers on technological advancement and diagnostic uses g magnetic resonance imaging. A comparative evaluation with computerized tomography is presented. Topics covered are imaging principles g magnetic resonance;instrumentation of magnetic resonance (MR);pathophysiology;quality and limitations g images;NMR imaging of brain and spinal cord;MR spectroscopy and its applications;neuroanatomy;Congenital malformations of brain and MR imaging;planning g MR imaging of spine and head and neck imaging

Nuclear magnetic resonance spectroscopy and imaging

International Nuclear Information System (INIS)

Jiang Weiping; Wang Qi; Zhou Xin

2013-01-01

This paper briefly introduces the basic principle of nuclear magnetic resonance (NMR). Protein's structures and functions and dynamics studied by liquid NMR are elaborated; methods for enhancing the resolution of solid state NMR and its applications are discussed; the principle of magnetic resonance imaging (MRI) is interpreted, and applications in different aspects are reviewed. Finally, the progress of NMR is commented. (authors)

Acromial Findings Associated with Rotator cuff's Lesions in Magnetic Resonance

International Nuclear Information System (INIS)

Avila, Mercedes; Atencio, Elizabeth; Moreno, Franklin

2008-01-01

The objective is to evaluate by means of magnetic resonance the acromial alterations associated to rotator cuff (RC) lesions (MR). Materials and methods: A prospective, descriptive and cross-sectional type study was performed in 30 patients aged between 40 and 70 years who attended the Resomer imaging center during the period comprised between October-December 2007, with clinical diagnosis of RC lesion, using a 1.5 T magnet. Results: Most of the studied population were females (66.67%), the mean age being of 56.93 years with a typical deviation of 8.75, with partial lesions in 63.33%, Type II acromion was the dominant acromion in 50%, of anterior orientation (90%), with absent os acromiale (96.66%). Likewise, clavicular and acromial articular hypertrophy was demonstrated in 93.33% of cases. The glenoid-acromion distance had a mean value of 3.15 cm and a typical deviation of 0.55 while the glenoid-humeral distance was 4.65 cm with a typical deviation of 0.46 and the acromial index of 0.67. The humeral-acromion space exhibited a mean value of 6.3 mm with a typical deviation of 1.72. Conclusion: The predominantly degenerative acromial alterations are a conditioning factor of compression resulting from incarceration in the clamp form with a larger > supraspinous tendon wear-out with later affectation to the remaining tendons of the RC as the exposure evolves.

Diagnostic apparatus employing nuclear magnetic resonance

International Nuclear Information System (INIS)

Hoshino, K.; Yamada, N.; Yoshitome, E.; Matsuura, H.

1987-01-01

An NMR diagnostic apparatus is described comprising means for applying a primary magnetic field to a subject; means for applying RF pulses to the subject to give nuclear magnetic resonance to the nuclei of atoms in the subject; means for applying gradient magnetic fields to project an NMR signal of the nuclei at least in one direction; means for observing the NMR signal projected by the gradient magnetic fields applying means; and arithmetic means for constructing a distribution of information on resonance energy as an image from an output signal from the observing means; wherein the gradient magnetic fields applying means comprises means for applying the gradient magnetic fields at a predetermined time and for not applying the gradient magnetic fields at another predetermined time, during the time period of one view; and wherein the gradient magnetic fields applying means further comprises means for measuring the NMR signal during the predetermined time when the gradient magnetic fields are applied, and means for measuring the intensity of the primary magnetic field during the other predetermined time when no gradient magnetic fields are applied

Children's (Pediatric) Magnetic Resonance Imaging

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Full Text Available ... immediately after the exam. A few patients experience side effects from the contrast material, including nausea and local ... Related Articles and Media Catheter Angiography Magnetic Resonance, Functional (fMRI) - Brain Children's (Pediatric) CT (Computed Tomography) Magnetic ...

Magnetic resonance angiography of the pediatric abdomen and pelvis: techniques and imaging findings.

Science.gov (United States)

Sada, David M; Vellody, Ranjith; Liu, Peter S

2013-11-01

Although traditional catheter-based angiography has been the gold standard for pediatric abdominal and pelvic vascular imaging for the past several decades, advances in magnetic resonance angiography (MRA) have made it a viable alternative. MRA offers several advantages in that it is noninvasive, can be performed without ionizing radiation, and does not necessarily rely on contrast administration. The ability of modern MRA techniques to define variant vascular anatomy and detect vascular disease may obviate traditional angiography in some patients. Copyright © 2013 Elsevier Inc. All rights reserved.

Evaluation of nuclear magnetic resonance spectroscopy variability

Energy Technology Data Exchange (ETDEWEB)

Barreto, Felipe Rodrigues; Salmon, Carlos Ernesto Garrido, E-mail: garrido@ffclrp.usp.br [Universidade de Sao Paulo (FFCLRP/USP), Ribeirao Preto, SP (Brazil). Fac. de Filisofia, Ciencias e Letras; Otaduy, Maria Concepcion Garcia [Universidade de Sao Paulo (FAMUS/USP), Sao Paulo, SP (Brazil). Fac. de Medicina. Departamento de Radiologia

2014-11-01

Introduction: the intrinsically high sensitivity of Magnetic Resonance Spectroscopy (MRS) causes considerable variability in metabolite quantification. In this study, we evaluated the variability of MRS in two research centers using the same model of magnetic resonance image scanner. Methods: two metabolic phantoms were created to simulate magnetic resonance spectra from in vivo hippocampus. The phantoms were filled with the same basic solution containing the following metabolites: N-acetyl-aspartate, creatine, choline, glutamate, glutamine and inositol. Spectra were acquired over 15 months on 26 acquisition dates, resulting in a total of 130 spectra per center. Results: the phantoms did not undergo any physical changes during the 15-month period. Temporal analysis from both centers showed mean metabolic variations of 3.7% in acquisitions on the same day and of 8.7% over the 15-month period. Conclusion: The low deviations demonstrated here, combined with the high specificity of Magnetic Resonance Spectroscopy, confirm that it is feasible to use this technique in multicenter studies in neuroscience research. (author)

Magnetic Resonance Imaging (MRI): Lumbar Spine (For Parents)

Science.gov (United States)

... Staying Safe Videos for Educators Search English Español Magnetic Resonance Imaging (MRI): Lumbar Spine KidsHealth / For Parents / Magnetic Resonance Imaging (MRI): Lumbar Spine What's in this article? ...

Nuclear magnetic resonance and earth magnetic field

International Nuclear Information System (INIS)

Anon.

1998-01-01

Nuclear magnetic resonance concerns nuclei whose spin is different from 0. These nuclei exposed to a magnetic field is comparable to a peg top spinning around its axis while being moved by a precession movement called Larmor precession. This article presents an experiment whose aim is to reveal nuclear magnetism of nuclei by observing Larmor precession phenomena due to the earth magnetic field. The earth magnetic field being too weak, it is necessary to increase the magnetization of the sample during a polarization phase. First the sample is submitted to a magnetic field B perpendicular to the earth magnetic field B 0 , then B is cut off and the nuclei move back to their equilibrium position by executing a precession movement due to B 0 field. (A.C.)

Resonance double magnetic bremsstrahlung in a strong magnetic field

International Nuclear Information System (INIS)

Fomin, P.I.; Kholodov, R.I.

2003-01-01

The possibility of resonance double magnetic bremsstrahlung in the approximation of weakly excited electron states in a strong external magnetic field is analyzed. The differential probability of this process in the Breit-Wigner form is obtained. The probability of double magnetic bremsstrahlung (second-order process of perturbation theory) is compared with the probability of magnetic bremsstrahlung (first-order process of perturbation theory)

Evaluation of urogenital fistulas by magnetic resonance urography

International Nuclear Information System (INIS)

Mamere, Augusto Elias; Coelho, Rafael Darahem Souza; Cecin, Alexandre Oliveira; Feltrin, Leonir Terezinha; Lucchesi, Fabiano Rubiao; Seabra, Daniel

2008-01-01

Objective: Vesicovaginal and ureterovaginal fistulas are unusual complications secondary to pelvic surgery or pelvic diseases. The therapeutic success in these cases depends on an appropriate preoperative evaluation for diagnosis and visualization of the fistulous tract. The present study is aimed at demonstrating the potential of magnetic resonance urography for the diagnosis of vesicovaginal and ureterovaginal fistulas as well as for defining the fistulous tracts. Materials And Methods: Seven female patients clinically diagnosed with vesicovaginal or ureterovaginal fistulas had their medical records, radiological and magnetic resonance images retrospectively reviewed. Magnetic resonance urography included 3D-HASTE sequences with fat saturation. Results: Six patients presented vesicovaginal fistulas and, in one patient, a right-sided ureterovaginal fistula was diagnosed. Magnetic resonance urography allowed the demonstration of the fistulous tract in six (85.7%) of the seven patients evaluated in the present study, without the need of bladder catheterization or contrast injection. Conclusion: This study demonstrates both the potential and applicability of magnetic resonance urography in the evaluation of these types of fistulas. (author)

Childhood temporal lobe epilepsy: correlation between electroencephalography and magnetic resonance spectroscopy: a case-control study.

Science.gov (United States)

Azab, Seham Fa; Sherief, Laila M; Saleh, Safaa H; Elshafeiy, Mona M; Siam, Ahmed G; Elsaeed, Wafaa F; Arafa, Mohamed A; Bendary, Eman A; Sherbiny, Hanan S; Elbehedy, Rabab M; Aziz, Khalid A

2015-04-18

The diagnosis of epilepsy should be made as early as possible to give a child the best chance for treatment success and also to decrease complications such as learning difficulties and social and behavioral problems. In this study, we aimed to assess the ability of magnetic resonance spectroscopy (MRS) in detecting the lateralization side in patients with Temporal lobe epilepsy (TLE) in correlation with EEG and MRI findings. This was a case-control study including 40 patients diagnosed (clinically and by EEG) as having temporal lobe epilepsy aged 8 to 14 years (mean, 10.4 years) and 20 healthy children with comparable age and gender as the control group. All patients were subjected to clinical examination, interictal electroencephalography and magnetic resonance imaging (MRI). Proton magnetic resonance spectroscopic examination (MRS) was performed to the patients and the controls. According to the findings of electroencephalography, our patients were classified to three groups: Group 1 included 20 patients with unitemporal (lateralized) epileptic focus, group 2 included 12 patients with bitemporal (non-lateralized) epileptic focus and group 3 included 8 patients with normal electroencephalography. Magnetic resonance spectroscopy could lateralize the epileptic focus in 19 patients in group 1, nine patients in group2 and five patients in group 3 with overall lateralization of (82.5%), while electroencephalography was able to lateralize the focus in (50%) of patients and magnetic resonance imaging detected lateralization of mesial temporal sclerosis in (57.5%) of patients. Magnetic resonance spectroscopy is a promising tool in evaluating patients with epilepsy and offers increased sensitivity to detect temporal pathology that is not obvious on structural MRI imaging.

Object-oriented magnetic resonance classes and objects, calculations and computations

CERN Document Server

Mehring, Michael

2001-01-01

This book presents, for the first time, a unified treatment of the quantum mechanisms of magnetic resonance, including both nuclear magnetic resonance (NMR) and electron spin resonance (ESR). Magnetic resonance is perhaps the most advanced type of spectroscopy and it is applied in biology, chemistry, physics, material science, and medicine. If applied in conjunction with spectroscopy, the imaging version of magnetic resonance has no counterpart in any type of experimental technique. The authors present explanations and applications from fundamental to advanced levels. Additionally, the

Extra-adrenal pheochromocytoma in pregnancy: ultrasonography and magnetic resonance imaging findings

Energy Technology Data Exchange (ETDEWEB)

Carson, B.J.W.; Johnston, M.A.; Iwaniuk, G.

1995-04-01

The case of a 24-year-old woman with extra-adrenal pheochromocytoma during pregnancy was described. Initial ultrasonography (US) at 27 weeks gestational age failed to show the pheochromocytoma, which was subsequently found by US at 35 weeks gestational age. Magnetic resonance imaging (MRI) provided diagnostic confirmation, as well as important information used by the obstetrician and the surgeon in operative planning. MRI proved to be ideally suited to investigation of extra-adrenal pheochromocytomas in pregnancy because it does not use ionizing radiation, and it has multiplanar capability and high contrast resolution. In the case described, the lesion was demonstrated with all MRI pulse sequences, but was best visualized with turbo spin-echo T2-weighted imaging, as well as with fat-suppressed imaging. 7 refs., 2 figs.

Diagnosis of pericardial cysts using diffusion weighted magnetic resonance imaging: A case series

Directory of Open Access Journals (Sweden)

Mousavi Negareh

2011-09-01

Full Text Available Abstract Introduction Congenital pericardial cysts are benign lesions that arise from the pericardium during embryonic development. The diagnosis is based on typical imaging features, but atypical locations and signal magnetic resonance imaging sequences make it difficult to exclude other lesions. Diffusion-weighted magnetic resonance imaging is a novel method that can be used to differentiate tissues based on their restriction to proton diffusion. Its use in differentiating pericardial cysts from other pericardial lesions has not yet been described. Case presentation We present three cases (a 51-year-old Caucasian woman, a 66-year-old Caucasian woman and a 77-year-old Caucasian woman with pericardial cysts evaluated with diffusion-weighted imaging using cardiac magnetic resonance imaging. Each lesion demonstrated a high apparent diffusion coefficient similar to that of free water. Conclusion This case series is the first attempt to investigate the utility of diffusion-weighted magnetic resonance imaging in the assessment of pericardial cysts. Diffusion-weighted imaging may be a useful noninvasive diagnostic tool for pericardial cysts when conventional imaging findings are inconclusive.

Theoretical study of ferromagnetic resonance in exchange - coupled magnetic / nonmagnetic / magnetic multilayer structure

International Nuclear Information System (INIS)

Oezdogan, K.; Oezdemir, M.; Yalcin, O.; Aktas, B.

2002-01-01

The dispersion relation on ferromagnetic films was calculation by using torque equation of motion with a damping term. The total energy including zeeman, demagnetizing and anisotropy energy terms was used to get ferromagnetic resonance frequency for both uniform and higher order spin wave modes. In antiferromagnetic films, the torque equation of motion for each sub-lattice were written to derive an expression for the dispersion relation. The magnetic trilayer system under investigation consist of two ferromagnetic layers separated by a nonmagnetic layer. The dispersion relation of magnetic/nonmagnetic/magnetic three layers is calculated by using Landau-Lifshitz dynamic equation of motion for the magnetization with interlayer exchange energy. As for the exchange-coupled resonance of ferromagnetic resonance (FMR), the theoretical study has been calculated for both symmetrical and asymmetrical structures. In this systems, the exchange-coupling parameter A 12 between neighboring layers was used to get resonance fields as a function of the angle between the magnetization vectors of each magnetic layers

Magnetic elliptical polarization of Schumann resonances

International Nuclear Information System (INIS)

Sentman, D.D.

1987-01-01

Measurements of orthogonal, horizontal components of the magnetic field in the ELF range obtained during September 1985 show that the Schumann resonance eigenfrequencies determined separately for the north-south and east-west magnetic components differ by as much as 0.5 Hz, suggesting that the underlying magnetic signal is not linearly polarized at such times. The high degree of magnetic ellipticity found suggests that the side multiplets of the Schumann resonances corresponding to azimuthally inhomogeneous normal modes are strongly excited in the highly asymmetric earth-ionosphere cavity. The dominant sense of polarization over the measurement passband is found to be right-handed during local daylight hours, and to be left-handed during local nighttime hours. 16 references

Accuracy of magnetic resonance in identifying traumatic intraarticular knee lesions

International Nuclear Information System (INIS)

Vaz, Carlos Eduardo Sanches; Camargo, Olavo Pires de; Santana, Paulo Jose de; Valezi, Antonio Carlos

2005-01-01

Purpose: To evaluate the diagnostic accuracy of magnetic resonance imaging of the knee in identifying traumatic intraarticular knee lesions. Method: 300 patients with a clinical diagnosis of traumatic intraarticular knee lesions underwent prearthoscopic magnetic resonance imaging. The sensitivity, specificity, positive predictive value, negative predictive value, likelihood ratio for a positive test, likelihood ratio for a negative test, and accuracy of magnetic resonance imaging were calculated relative to the findings during arthroscopy in the studied structures of the knee (medial meniscus, lateral meniscus, anterior cruciate ligament, posterior cruciate ligament, and articular cartilage). Results: Magnetic resonance imaging produced the following results regarding detection of lesions: medial meniscus: sensitivity 97.5%, specificity 92.9%, positive predictive value 93.9%, positive negative value 97%, likelihood positive ratio 13.7, likelihood negative ratio 0.02, and accuracy 95.3%; lateral meniscus: sensitivity 91.9%, specificity 93.6%, positive predictive value 92.7%, positive negative value 92.9%, likelihood positive ratio 14.3, likelihood negative ratio 0.08, and accuracy 93.6%; anterior cruciate ligament: sensitivity 99.0%, specificity 95.9%, positive predictive value 91.9%, positive negative value 99.5%, likelihood positive ratio 21.5, likelihood negative ratio 0.01, and accuracy 96.6%; posterior cruciate ligament: sensitivity 100%, specificity 99%, positive predictive value 80.0%, positive negative value 100%, likelihood positive ratio 100, likelihood negative ratio 0.01, and accuracy 99.6%; articular cartilage: sensitivity 76.1%, specificity 94.9%, positive predictive value 94.7%, positive negative value 76.9%, likelihood positive ratio 14.9, likelihood negative ratio 0.25, and accuracy 84.6%. Conclusion: Magnetic resonance imaging is a satisfactory diagnostic tool for evaluating meniscal and ligamentous lesions of the knee, but it is unable to clearly

Accuracy of magnetic resonance in identifying traumatic intraarticular knee lesions

Directory of Open Access Journals (Sweden)

Vaz Carlos Eduardo Sanches

2005-01-01

Full Text Available PURPOSE: To evaluate the diagnostic accuracy of magnetic resonance imaging of the knee in identifying traumatic intraarticular knee lesions. METHOD: 300 patients with a clinical diagnosis of traumatic intraarticular knee lesions underwent prearthoscopic magnetic resonance imaging. The sensitivity, specificity, positive predictive value, negative predictive value, likelihood ratio for a positive test, likelihood ratio for a negative test, and accuracy of magnetic resonance imaging were calculated relative to the findings during arthroscopy in the studied structures of the knee (medial meniscus, lateral meniscus, anterior cruciate ligament, posterior cruciate ligament, and articular cartilage. RESULTS: Magnetic resonance imaging produced the following results regarding detection of lesions: medial meniscus: sensitivity 97.5%, specificity 92.9%, positive predictive value 93.9%, positive negative value 97%, likelihood positive ratio 13.7, likelihood negative ratio 0.02, and accuracy 95.3%; lateral meniscus: sensitivity 91.9%, specificity 93.6%, positive predictive value 92.7%, positive negative value 92.9%, likelihood positive ratio 14.3, likelihood negative ratio 0.08, and accuracy 93.6%; anterior cruciate ligament: sensitivity 99.0%, specificity 95.9%, positive predictive value 91.9%, positive negative value 99.5%, likelihood positive ratio 21.5, likelihood negative ratio 0.01, and accuracy 96.6%; posterior cruciate ligament: sensitivity 100%, specificity 99%, positive predictive value 80.0%, positive negative value 100%, likelihood positive ratio 100, likelihood negative ratio 0.01, and accuracy 99.6%; articular cartilage: sensitivity 76.1%, specificity 94.9%, positive predictive value 94.7%, positive negative value 76.9%, likelihood positive ratio 14.9, likelihood negative ratio 0.25, and accuracy 84.6%. CONCLUSION: Magnetic resonance imaging is a satisfactory diagnostic tool for evaluating meniscal and ligamentous lesions of the knee, but it is

Clinical relevance of magnetic resonance imaging and magnetic resonance spectroscopy for the cirrhotic without overt hepatic encephalopathy

Energy Technology Data Exchange (ETDEWEB)

Fujishima, Yukou; Kato, Akinobu; Suzuki, Kazuyuki [Iwate Medical Univ., Morioka (Japan). School of Medicine

1999-04-01

To clarify the changes of pallidal high intensity on T1-weighted magnetic resonance imaging (MRI) and brain metabolites on magnetic resonance spectroscopy (MRS) as related to the severity of hepatic functions, the concentrations of blood ammonia (B-NH{sub 3}) and the levels of trace elements (Mn, Cu and Zn), 30 patients with liver cirrhosis without hepatic encephalopathy (HE) and 5 age-matched healthy control subjects underwent MRI and proton MRS. Pallidal high intensity (Pl index) and glutamine are higher in cirrhosis, and myo-inositol is lower than that of control statistically. In cirrhosis, there were statistically negative correlation between B-NH{sub 3} and myo-inositol and positive correlation between B-NH{sub 3} and glutamine. There was a statistically lower myo-inositol and higher Pl index, glutamine as the severity of hepatic functions increased. Furthermore there was a statistically positive correlation between Pl index and Mn. These data suggest that the changes of MRI and MRS findings already detected in cirrhosis without HE and these abnormalities may be reflect the B-NH{sub 3} and Mn metabolism and the severity of the hepatic functions. (author)

Clinical relevance of magnetic resonance imaging and magnetic resonance spectroscopy for the cirrhotic without overt hepatic encephalopathy

International Nuclear Information System (INIS)

Fujishima, Yukou; Kato, Akinobu; Suzuki, Kazuyuki

1999-01-01

To clarify the changes of pallidal high intensity on T1-weighted magnetic resonance imaging (MRI) and brain metabolites on magnetic resonance spectroscopy (MRS) as related to the severity of hepatic functions, the concentrations of blood ammonia (B-NH 3 ) and the levels of trace elements (Mn, Cu and Zn), 30 patients with liver cirrhosis without hepatic encephalopathy (HE) and 5 age-matched healthy control subjects underwent MRI and proton MRS. Pallidal high intensity (Pl index) and glutamine are higher in cirrhosis, and myo-inositol is lower than that of control statistically. In cirrhosis, there were statistically negative correlation between B-NH 3 and myo-inositol and positive correlation between B-NH 3 and glutamine. There was a statistically lower myo-inositol and higher Pl index, glutamine as the severity of hepatic functions increased. Furthermore there was a statistically positive correlation between Pl index and Mn. These data suggest that the changes of MRI and MRS findings already detected in cirrhosis without HE and these abnormalities may be reflect the B-NH 3 and Mn metabolism and the severity of the hepatic functions. (author)

Knee dislocations: a magnetic resonance imaging study correlated with clinical and operative findings

Energy Technology Data Exchange (ETDEWEB)

Bui, Kimmie L. [Cleveland Clinic, Department of Radiology, Cleveland, OH (United States); Cleveland Clinic, Department of Radiology, HB6, Cleveland, OH (United States); Ilaslan, Hakan; Sundaram, Murali [Cleveland Clinic, Department of Radiology, Cleveland, OH (United States); Parker, Richard D. [Cleveland Clinic, Department of Orthopaedics, Cleveland, OH (United States)

2008-07-15

Our objectives were to determine retrospectively the prevalence, patients' demographics, mechanism of injury, combination of torn ligaments, associated intra-articular and extra-articular injuries, fractures, bone bruises, femoral-tibial alignment and neurovascular complications of knee dislocations as evaluated by magnetic resonance (MR) imaging. From 17,698 consecutive knee examinations by magnetic resonance imaging (MRI) over a 6-year period, 20 patients with knee dislocations were identified. The medical records of these patients were subsequently reviewed for relevant clinical history, management and operative findings. The prevalence of knee dislocations was 0.11% [95% confidence interval (95% CI) 0.06-0.16]. There were 16 male patients and four female patients, with ages ranging from 15 years to 76 years (mean 31 years). Fifteen patients had low-velocity injuries (75%), of which 11 were amateur sports related and four were from falls. Four patients (20%) had suffered high-velocity trauma (motor vehicle accidents). One patient had no history available. Anatomic alignment was present at imaging in 16 patients (80%). Eighteen patients had three-ligament tears, two had four-ligament tears. The four-ligament tears occurred with low-velocity injuries. The anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) were torn in every patient; the lateral collateral ligament (LCL) was torn in 50%, and the medial collateral ligament (MCL) in 60%. Intra-articular injuries included meniscal tears (five in four patients), fractures (eight in seven patients), bone bruises (15 patients), and patellar retinaculum tears (eight partial, two complete). The most common extra-articular injury was a complete biceps femoris tendon tear (five, 25%). There were two popliteal tendon tears and one iliotibial band tear. One patient had received a vascular injury following a motor vehicle accident (MVA) and had been treated prior to undergoing MRI. Bone bruises

Functional magnetic resonance imaging by visual stimulation

International Nuclear Information System (INIS)

Nishimura, Yukiko; Negoro, Kiyoshi; Morimatsu, Mitsunori; Hashida, Masahiro

1996-01-01

We evaluated functional magnetic resonance images obtained in 8 healthy subjects in response to visual stimulation using a conventional clinical magnetic resonance imaging system with multi-slice spin-echo echo planar imaging. Activation in the visual cortex was clearly demonstrated by the multi-slice experiment with a task-related change in signal intensity. In addition to the primary visual cortex, other areas were also activated by a complicated visual task. Multi-slice spin-echo echo planar imaging offers high temporal resolution and allows the three-dimensional analysis of brain function. Functional magnetic resonance imaging provides a useful noninvasive method of mapping brain function. (author)

Novel diffusion-weighted magnetic resonance imaging findings in leptomeningeal carcinomatosis: a case report

Energy Technology Data Exchange (ETDEWEB)

Hu, Y.F.; Chang, F.C.; Hu, H.H.; Hsu, L.C. [Taipei Veterans General Hospital, Taiwan (China). Depts. of Internal Medicine and Radiology, and Neurological Inst.

2006-12-15

This report presents a rare case of leptomeningeal carcinomatosis initially presenting with mental impairment and rapidly progressing to coma without any history of malignancy. In addition to highlighting the diagnostic difficulties, the linear high signal intensity along the cortex on the diffusion-weighted imaging (DWI) sequence of magnetic resonance (MR) imaging was identified accidentally. High signal change in the corresponding areas was also noted on unenhanced fluid-attenuated inversion recovery (FLAIR) MR imaging, which may be a novel method of diagnosing leptomeningeal carcinomatosis, which should be studied further.

Musculoskeletal applications of magnetic resonance imaging: Council on Scientific Affairs

International Nuclear Information System (INIS)

Harms, S.E.; Fisher, C.F.; Fulmer, J.M.

1989-01-01

Magnetic resonance imaging provides superior contrast, resolution, and multiplanar imaging capability, allowing excellent definition of soft-tissue and bone marrow abnormalities. For these reasons, magnetic resonance imaging has become a major diagnostic imaging method for the evaluation of many musculoskeletal disorders. The applications of magnetic resonance imaging for musculoskeletal diagnosis are summarized and examples of common clinical situations are given. General guidelines are suggested for the musculoskeletal applications of magnetic resonance imaging

Hallervorden Spatz syndrome: magnetic resonance findings. Case report; Sindrome de Hallervorden Spatz: achados na ressonancia magnetica. Relato de caso

Energy Technology Data Exchange (ETDEWEB)

Farage, Luciano; Castro, Mario Augusto Padula; Macedo, Tulio Augusto Alves [Universidade Federal de Uberlandia, MG (Brazil). Hospital de Clinicas. Setor de Radiologia; Assis, Marcelo Cardoso de [Universidade Federal de Uberlandia, MG (Brazil). Faculdade de Medicina. Dept. de Cirurgia; Souza, Lincoln Pereira de; Freitas, Luiz Oliveira de [Universidade Federal de Uberlandia, MG (Brazil). Dept. de Clinica Medica

2004-09-01

Hallervorden-Spatz syndrome is a neuro degenerative disease, autosomic recessive with two clinical features: early and late onset. Psychiatric, pyramidal and extrapyramidal signs are present in the late subtype. We report the case of a 41-old woman with extrapyramidal signs. Magnetic resonance imaging (MRI) showed the eye-of-the-tiger sign in the medial globus pallidus. This is due to a gliosis (increased signal) and accumulation of surrounding iron (decreased signal intensity) in long T R sequences. There is a strong relationship between MRI findings and the gene mutation responsible for this disease. It makes the MRI sensible for diagnosing this syndrome. (author)

Magnetic resonance force microscopy of paramagnetic electron spins at millikelvin temperatures.

Science.gov (United States)

Vinante, A; Wijts, G; Usenko, O; Schinkelshoek, L; Oosterkamp, T H

2011-12-06

Magnetic resonance force microscopy (MRFM) is a powerful technique to detect a small number of spins that relies on force detection by an ultrasoft magnetically tipped cantilever and selective magnetic resonance manipulation of the spins. MRFM would greatly benefit from ultralow temperature operation, because of lower thermomechanical noise and increased thermal spin polarization. Here we demonstrate MRFM operation at temperatures as low as 30 mK, thanks to a recently developed superconducting quantum interference device (SQUID)-based cantilever detection technique, which avoids cantilever overheating. In our experiment, we detect dangling bond paramagnetic centres on a silicon surface down to millikelvin temperatures. Fluctuations of such defects are supposedly linked to 1/f magnetic noise and decoherence in SQUIDs, as well as in several superconducting and single spin qubits. We find evidence that spin diffusion has a key role in the low-temperature spin dynamics.

Magnetic resonance of native defects of spin-Peierls magnetics CuGeO3

International Nuclear Information System (INIS)

Smirnov, A.I.; Glazkov, V.N.; Leonyuk, L.I.; Vetkin, A.G.; Eremina, R.M.

1998-01-01

Magnetic resonance within 9-75 GHz frequency range and 1.2-25 K temperature range was studied in pure monocrystalline spin-Peierls CuGwO 3 . Splitting of the magnetic resonance line is observed within temperature range below 5 K. Analysis of magnetic resonance spectra at various directions of magnetic field and under various temperatures enables to set off EPR-signals of spin-Peierls phase defects with S=1/2 and defects with S=1 from these components; g-factor corresponding to these EPR signals is similar one and close to values typical for Cu 2+ ion [ru

Green’s function theory of ferromagnetic resonance in magnetic superlattices with damping

International Nuclear Information System (INIS)

Qiu, R.K.; Guo, F.F.; Zhang, Z.D.

2016-01-01

We explore a quantum Green’s-function method to study the resonance absorption of magnetic materials. The relationship between the resonance magnon (spin wave) density and the resonance frequency of a superlattice consisting of two magnetic layers with damping and antiferromagnetic interlayer exchange coupling is studied. The effects of temperature, interlayer coupling, anisotropy, external magnetic field and damping on the the resonance frequency and resonance magnon density are investigated. The resonance excitation probability for a magnon is proportional to the resonance magnon density. In the classic methods, the imaginary part of magnetic permeability represents the resonance absorption in magnetic materials. In the quantum approach, the resonance magnon density can be used to estimate the strength of the resonance absorption. In the present work, a quantum approach is developed to study resonance absorption of magnetic materials and the results show the method to obtain a magnetic multilayered materials with both high resonance frequency and high resonance absorption.

Green’s function theory of ferromagnetic resonance in magnetic superlattices with damping

Energy Technology Data Exchange (ETDEWEB)

Qiu, R.K., E-mail: rkqiu@163.com [Shenyang University of Technology, Shenyang 110870 (China); Guo, F.F. [Shenyang University of Technology, Shenyang 110870 (China); Zhang, Z.D. [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China)

2016-02-01

We explore a quantum Green’s-function method to study the resonance absorption of magnetic materials. The relationship between the resonance magnon (spin wave) density and the resonance frequency of a superlattice consisting of two magnetic layers with damping and antiferromagnetic interlayer exchange coupling is studied. The effects of temperature, interlayer coupling, anisotropy, external magnetic field and damping on the the resonance frequency and resonance magnon density are investigated. The resonance excitation probability for a magnon is proportional to the resonance magnon density. In the classic methods, the imaginary part of magnetic permeability represents the resonance absorption in magnetic materials. In the quantum approach, the resonance magnon density can be used to estimate the strength of the resonance absorption. In the present work, a quantum approach is developed to study resonance absorption of magnetic materials and the results show the method to obtain a magnetic multilayered materials with both high resonance frequency and high resonance absorption.

Magnetic resonance imaging findings in bipartite medial cuneiform – a potential pitfall in diagnosis of midfoot injuries: a case series

Directory of Open Access Journals (Sweden)

Elias Ilan

2008-08-01

Full Text Available Abstract Introduction The bipartite medial cuneiform is an uncommon developmental osseous variant in the midfoot. To our knowledge, Magnetic Resonance Imaging (MRI characteristics of a non-symptomatic bipartite medial cuneiform have not been described in the orthopaedic literature. It is important for orthopaedic foot and ankle surgeons, musculoskeletal radiologists, and for podiatrists to identify this osseous variant as it may be mistakenly diagnosed as a fracture or not recognized as a source of non-traumatic or traumatic foot pain, which may sometimes even require surgical treatment. Case presentations In this report, we describe the characteristics of three cases of bipartite medial cuneiform on Magnetic Resonance Imaging and contrast its appearance to that of a medial cuneiform fracture. Conclusion A bipartite medial cuneiform is a rare developmental anomaly of the midfoot and may be the source of midfoot pain. Knowledge about its characteristic appearance on magnetic resonance imaging is important because it is a potential pitfall in diagnosis of midfoot injuries.

Clinical magnetic resonance: imaging and spectroscopy

International Nuclear Information System (INIS)

Andrew, E.R.; Bydder, Graeme; Griffiths, John; Iles, Richard; Styles, Peter

1990-01-01

This book begins with a readable, comprehensive but non-mathematical introduction to the basic underlying principles of magnetic resonance. Further chapters include information on the theory and principles of MRI and MRS, the interpretation of MR images, the clinical applications and scope of MRI and MRS, practical aspects of spectroscopy and magnetic resonance, and also the practical problems associated with the siting, safety and operation of large MRI and MRS equipment. (author)

Magnetic resonance imaging of the wrist: Diagnostic performance statistics

International Nuclear Information System (INIS)

Hobby, Jonathan L.; Tom, Brian D.M.; Bearcroft, Philip W.P.; Dixon, Adrian K.

2001-01-01

AIM: To review the published diagnostic performance statistics for magnetic resonance imaging (MRI) of the wrist for tears of the triangular fibrocartilage complex, the intrinsic carpal ligaments, and for osteonecrosis of the carpal bones. MATERIALS AND METHODS: We used Medline and Embase to search the English language literature. Studies evaluating the diagnostic performance of MRI of the wrist in living patients with surgical confirmation of MR findings were identified. RESULTS: We identified 11 studies reporting the diagnostic performance of MRI for tears of the triangular fibrocartilage complex for a total of 410 patients, six studies for the scapho-lunate ligament (159 patients), six studies for the luno-triquetral ligament (142 patients) and four studies (56 patients) for osteonecrosis of the carpal bones. CONCLUSIONS: Magnetic resonance imaging is an accurate means of diagnosing tears of the triangular fibrocartilage and carpal osteonecrosis. Although MRI is highly specific for tears of the intrinsic carpal ligaments, its sensitivity is low. The diagnostic performance of MRI in the wrist is improved by using high-resolution T2* weighted 3D gradient echo sequences. Using current imaging techniques without intra-articular contrast medium, magnetic resonance imaging cannot reliably exclude tears of the intrinsic carpal ligaments. Hobby, J.L. (2001)

Pattern of magnetic resonance imaging and magnetic resonance venography changes in cerebral venous sinus thrombosis

International Nuclear Information System (INIS)

Zafar, A.; Ali, Z.

2012-01-01

Background: Cerebral venous sinus thrombosis is a common but highly under-recognised condition, which is missed not only by general practitioners but also by neurologists. Computerised tomography (CT) or magnetic resonance imaging (MRI) of brain alone is not sufficient to diagnose this condition. Objective of this study was to explore the pattern of magnetic resonance imaging (MRI) and magnetic resonance venography (MRV) changes in cerebral venous sinus thrombosis (CVST). Methods: This was a descriptive study in which 52 cases of cerebral venous sinus thrombosis with special emphasis on their MRI and MRV findings were included. The study was conducted in Neurology Unit, Lady Reading Hospital, Peshawar, Pakistan, from January 2010 to July 2011. All patients suffering from cerebral venous sinus thrombosis were included in the study. Multi-planar/multi-sequential, Tesla 1.5 MRI/MRV time of flight images were done in all cases where there was suspicion of cerebral venous sinus thrombosis. Results: Out of 52 patients with cerebral venous sinus thrombosis 41 (78.84%) were female and 11 (21.15%) were male. Mean age was 37+-5 years. Definite risk factors were found in 38 (73.076%) patients with pregnancy, use of oral contraceptives or puerperium being the most frequently found risk factor in 20 (73.076%) patients. Most common complaint was headache found in 41 (78.84%) patients, followed by focal neurological deficits, and altered mental status and seizures. Papilloedema was seen in 20 (38.46%) patients. The cerebral venous sinuses most frequently involved were transverse and sigmoid sinuses in 17 patients (32.69%) while superior sagittal sinus alone in 10 (19.23%) patients. Overall CT brain was normal in 30% and MRI brain in 23.07% patients; however, MRV of these patients revealed CVST. Conclusion: Imaging plays a primary role in the diagnosis of cerebral venous sinus thrombosis because the clinical picture of CVST is non-specific and highly variable. Thrombosis of

Magnetic resonance imaging in patients with panhypopituitarism

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Pozzi Mucelli, R.S. [Ist. di Radiologia, Univ. di Trieste, Ospedale di Cattinara (Italy); Frezza, F. [Ist. di Radiologia, Univ. di Trieste, Ospedale di Cattinara (Italy); Magnaldi, S. [Ist. di Radiologia, Univ. di Trieste, Ospedale di Cattinara (Italy); Proto, G. [Servizio di Endocrinologia, Ospedale Civile di Udine (Italy)

1992-02-01

Primary panhypopituitarism consists of functional deficiency of the anterior pituitary lobe, which appears during infancy or adolescence. The magnetic resonance findings in 10 patients with a history of primary hypopituitarism are presented. The findings include: reduced pituitary size in all cases; partially (8 cases) or totally (2 cases) empty sella; thin (4 cases), partially visible (3 cases) or absent (2 cases) pituitary stalk; absence of the posterior lobe in 9 cases; bright spot corresponding to an ectopic posterior lobe in 8 cases. These findings are similar to those already reported in pituitary dwarfism and may help understanding of the pathogenesis of the disease, which seems to be related to a pituitary stalk lesion. (orig.)

Magnetic resonance imaging in patients with panhypopituitarism

International Nuclear Information System (INIS)

Pozzi Mucelli, R.S.; Frezza, F.; Magnaldi, S.; Proto, G.

1992-01-01

Primary panhypopituitarism consists of functional deficiency of the anterior pituitary lobe, which appears during infancy or adolescence. The magnetic resonance findings in 10 patients with a history of primary hypopituitarism are presented. The findings include: reduced pituitary size in all cases; partially (8 cases) or totally (2 cases) empty sella; thin (4 cases), partially visible (3 cases) or absent (2 cases) pituitary stalk; absence of the posterior lobe in 9 cases; bright spot corresponding to an ectopic posterior lobe in 8 cases. These findings are similar to those already reported in pituitary dwarfism and may help understanding of the pathogenesis of the disease, which seems to be related to a pituitary stalk lesion. (orig.)

Role of chelates in magnetic resonance imaging studies

Directory of Open Access Journals (Sweden)

Tripathi Laxmi

2009-01-01

Full Text Available Imaging studies are tests performed with a variety of techniques that produce pictures of the inside of a patient′s body. Magnetic resonance imaging (MRI is an imaging technique based on the principles of nuclear magnetic resonance. MRI uses a powerful magnetic field, radio waves, and a computer to produce detailed pictures of organs, soft tissues, bone, and virtually all other internal body structures. Chelates have a wide application in such imaging techniques. Chelates in imaging studies are used alone as radioactive agents or conjugated to monoclonal antibodies or to DNA as radioactive agents. Technetium chelates and gadolinium chelates are being widely used as magnetic resonance contrast media.

Recommendations concerning magnetic resonance spectroscopy

International Nuclear Information System (INIS)

1986-01-01

In medicine the technique of nuclear magnetic resonance (NMR) is applied in the form of in vivo nuclear magnetic resonance spectroscopy (MRS). In vivo MRS can be carried out non-invasively. The committee of the Dutch Health Council briefly discusses the qualities and potentialities of the nuclei that will probably be used in future clinical spectroscopy: 31 P, 13 C, 1 H (and possibly 19 F and 23 Na). The committee discusses several possibilities of combining imaging and spectroscopy. The imaging of nuclei other than protons is also possible with MRS. Potential applications are considered in oncology, cardiology, neurology and hepatology. (Auth.)

Prebiopsy magnetic resonance spectroscopy and imaging in the diagnosis of prostate cancer

International Nuclear Information System (INIS)

Kumar, V.; Jagannathan, N.R.; Thulkar, S.; Kumar, R.

2012-01-01

Existing screening investigations for the diagnosis of early prostate cancer lack specificity, resulting in a high negative biopsy rate. There is increasing interest in the use of various magnetic resonance methods for improving the yield of transrectal ultrasound-guided biopsies of the prostate in men suspected to have prostate cancer. We review the existing status of such investigations. A literature search was carried out using the Pubmed database to identify articles related to magnetic resonance methods for diagnosing prostate cancer. References from these articles were also extracted and reviewed. Recent studies have focused on prebiopsy magnetic resonance investigations using conventional magnetic resonance imaging, dynamic contrast enhanced magnetic resonance imaging, diffusion weighted magnetic resonance imaging, magnetization transfer imaging and magnetic resonance spectroscopy of the prostate. This marks a shift from the earlier strategy of carrying out postbiopsy magnetic resonance investigations. Prebiopsy magnetic resonance investigations has been useful in identifying patients who are more likely to have a biopsy positive for malignancy. Prebiopsy magnetic resonance investigations has a potential role in increasing specificity of screening for early prostate cancer. It has a role in the targeting of biopsy sites, avoiding unnecessary biopsies and predicting the outcome of biopsies. (author)

Magnetic resonance instrumentation

International Nuclear Information System (INIS)

Bell, R.A.

1987-01-01

Magnetic resonance (MR), while opening new vistas to diagnostic medicine, utilizes equipment that is unfamiliar to most clinicians. Beyond learning to cope with new terms, such as spin-echo, T1, T2, and spin density, health care professionals are faced with the inclusion of magnetic and radiofrequency effects in their facilities produced by a complex array of devices. It is the purpose of this chapter to outline the components of an MR imaging system, to discuss their functions, and to note the variations in equipment commercially available

Nuclear magnetic resonance spectroscopy in organic chemistry. 2. ed.

International Nuclear Information System (INIS)

Zschunke, A.

1977-01-01

The fundamentals of nuclear magnetic resonance spectroscopy are discussed only briefly. The emphasis is laid on developing reader's ability to evaluate resonance spectra. The following topics are covered: principles of nuclear magnetic resonance spectroscopy; chemical shift and indirect nuclear spin coupling constants and their relation to the molecular structure; analysis of spectra; and uses for structural analysis and solution of kinetic problems, mainly with regard to organic compounds. Of interest to chemists and graduate students who want to make themselves acquainted with nuclear magnetic resonance spectroscopy

Autologous blood injection to the temporomandibular joint: magnetic resonance imaging findings

Energy Technology Data Exchange (ETDEWEB)

Candirili, Celal; Yuece, Serdar; Cavus, Umut Yuecel; Akin, Kayihan; Cakir, Banu [Fatih University Hospital, Ankara (Turkmenistan)

2012-03-15

The aim of this study was to investigate the effect of the autologous blood injection (ABI) for chronic recurrent temporomandibular joint (TMJ) dislocation using magnetic resonance imaging (MRI). ABI was applied to 14 patients who had chronic recurrent TMJ dislocation. MRIs of the patients were taken and compared before and one month after the injection. All of the patients had no dislocations of their TMJs on clinical examination one month after the injection. In the pre-injection, unilateral or bilateral TMJ dislocations were observed on MRIs in all patients. One month after the injection, TMJ dislocations were not observed in MRI evaluation of any patients. A significant structural change that caused by ABI was not observed. The procedure was easy to perform and it caused no foreign body reaction. However, it was unclear how the procedure prevented the dislocation.

Agreement between magnetic resonance imaging and ultrasonography in the classification of Schistosomal periportal fibrosis, according to Niamey's criteria

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Scortegagna Junior, Eduardo; Leao, Alberto Ribeiro de Souza; Sales, Danilo Moulin; Shigueoka, David Carlos; D' Ippolito, Giuseppe [Universidade Federal de Sao Paulo (UNIFESP-EPM), Sao Paulo, SP (Brazil). Dept. of Imaging Diagnosis]. E-mail: E-mail: giuseppe_dr@uol.com.br; Santos, Jose Eduardo Mourao; Colleoni Neto, Ramiro [Universidade Federal de Sao Paulo (UNIFESP-EPM), Sao Paulo, SP (Brazil); Aguiar, Luciane Aparecida Kopke de; Brant, Paulo Eugenio [Universidade Federal de Sao Paulo (UNIFESP-EPM), Sao Paulo, SP (Brazil). Dept. of Gastroenterology; Borges, Durval Rosa [Universidade Federal de Sao Paulo (UNIFESP-EPM), Sao Paulo, SP (Brazil). Dept. of Medicine

2008-01-15

Objective: To evaluate the reproducibility of magnetic resonance imaging and the agreement between ultrasound and magnetic resonance imaging in the classification of periportal fibrosis in patients with schistosomiasis based on Niamey's qualitative criteria. Materials and methods: A prospective, double-blinded study was conducted between February 2005 and June 2006 with 20 patients (10 men and 10 women, with ages ranging between 24 and 60 years, mean age 42.7 years) diagnosed with schistosomiasis mansoni. Both ultrasound and magnetic resonance images were independently evaluated by two experienced observers. Interobserver agreement was evaluated for findings of periportal fibrosis on magnetic resonance images and in a comparison between magnetic resonance and ultrasound images. Results: The analysis of magnetic resonance images showed total interobserver agreement in 14 patients (70%). The comparison between ultrasound and magnetic resonance imaging showed agreement between images in only six cases (30%) by observer 1, and in eight cases (40%) by observer 2. Conclusion: Magnetic resonance imaging presents a good reproducibility in the evaluation of periportal fibrosis in later stages of schistosomiasis, however, the correlation between magnetic resonance imaging and ultrasound is poor. (author)

Magnetic resonance imaging findings of periosteal interposition in a distal tibial Salter-Harris type I fracture with surgical correlation: A case report

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Kim, Nara; Jung, Jee Young; Kang, Ki Ser [Chung-Ang University Hospital, Seoul (Korea, Republic of)

2013-08-15

The complication of growth disturbance after physeal fracture of the distal tibia has been well recognized. Although irreducible fractures of the physis due to trapped soft tissue, including periosteum, are not common, it could still cause growth disturbances. Therefore, the detection of periosteal interposition with physeal injury on imaging study is important. We present a case of a 10-year-old girl with surgically confirmed periosteal interposition in the distal tibial Salter-Harris type I fracture, through magnetic resonance imaging findings.

Magnetic resonance imaging findings of periosteal interposition in a distal tibial Salter-Harris type I fracture with surgical correlation: A case report

International Nuclear Information System (INIS)

Kim, Nara; Jung, Jee Young; Kang, Ki Ser

2013-01-01

The complication of growth disturbance after physeal fracture of the distal tibia has been well recognized. Although irreducible fractures of the physis due to trapped soft tissue, including periosteum, are not common, it could still cause growth disturbances. Therefore, the detection of periosteal interposition with physeal injury on imaging study is important. We present a case of a 10-year-old girl with surgically confirmed periosteal interposition in the distal tibial Salter-Harris type I fracture, through magnetic resonance imaging findings.

Magnetic resonance imaging - first human images in Australia

International Nuclear Information System (INIS)

Baddeley, H.; Doddrell, D.M.; Brooks, W.M.; Field, J.; Irving, M.; Williams, J.E.

1986-01-01

The use of magnetic resonance imaging, in the demonstration of internal human anatomy and in the diagnosis of disease, has the major advantages that the technique is non-invasive, does not require the use of ionizing radiation and that it can demonstrate neurological and cardiovascular lesions that cannot be diagnosed easily by other imaging methods. The first magnetic resonance images of humans were obtained in Australia in October 1985 on the research instrument of the Queensland Medical Magnetic Resonance Research Centre, which is based at the Mater Hospital in Brisbane

Magnetic resonance imaging of radiation optic neuropathy

International Nuclear Information System (INIS)

Zimmerman, C.F.; Schatz, N.J.; Glaser, J.S.

1990-01-01

Three patients with delayed radiation optic neuropathy after radiation therapy for parasellar neoplasms underwent magnetic resonance imaging. The affected optic nerves and chiasms showed enlargement and focal gadopentetate dimeglumine enhancement. The magnetic resonance imaging technique effectively detected and defined anterior visual pathway changes of radionecrosis and excluded the clinical possibility of visual loss because of tumor recurrence

Giant magnetic modulation of a planar, hybrid metamolecule resonance

International Nuclear Information System (INIS)

Gregory, Simon A; Stenning, Gavin B G; Bowden, Graham J; De Groot, Peter A J; Zheludev, Nikolay I

2014-01-01

Coupling magnetic elements to metamaterial structures creates hybrid metamolecules with new opportunities. Here we report on the magnetic control of a metamolecule resonance, by utilizing the interaction between a single split ring resonator (SRR) and a magnetic thin film of permalloy. To suppress eddy current shielding, the permalloy films are patterned into arrays of 30–500 μm diameter discs. Strong hybridized resonances were observed at the anticrossing between the split ring resonance and the ferromagnetic resonance (FMR) of the permalloy. In particular, it is possible to achieve 40 dB modulation of the electric (symmetric) mode of the SRR on sweeping the applied magnetic field through the SRR/FMR anticrossing. The results open the way to the design of planar metamaterials, with potential applications in nonlinear metamaterials, tunable metamaterials and spintronics. (papers)

Magnetic resonance of rubidium atoms passing through a multi-layered transmission magnetic grating

International Nuclear Information System (INIS)

Nagata, Y; Kurokawa, S; Hatakeyama, A

2017-01-01

We measured the magnetic resonance of rubidium atoms passing through periodic magnetic fields generated by two types of multi-layered transmission magnetic grating. One of the gratings reported here was assembled by stacking four layers of magnetic films so that the direction of magnetization alternated at each level. The other grating was assembled so that the magnetization at each level was aligned. For both types of grating, the experimental results were in good agreement with our calculations. We studied the feasibility of extending the frequency band of the grating and narrowing its resonance linewidth by performing calculations. For magnetic resonance precision spectroscopy, we conclude that the multi-layered transmission magnetic grating can generate periodic fields with narrower linewidths at higher frequencies when a larger number of layers are assembled at a shorter period length. Moreover, the frequency band of this type of grating can potentially achieve frequencies of up to hundreds of PHz. (paper)

Magnetic resonance imaging of breast implants.

Science.gov (United States)

Shah, Mala; Tanna, Neil; Margolies, Laurie

2014-12-01

Silicone breast implants have significantly evolved since their introduction half a century ago, yet implant rupture remains a common and expected complication, especially in patients with earlier-generation implants. Magnetic resonance imaging is the primary modality for assessing the integrity of silicone implants and has excellent sensitivity and specificity, and the Food and Drug Administration currently recommends periodic magnetic resonance imaging screening for silent silicone breast implant rupture. Familiarity with the types of silicone implants and potential complications is essential for the radiologist. Signs of intracapsular rupture include the noose, droplet, subcapsular line, and linguine signs. Signs of extracapsular rupture include herniation of silicone with a capsular defect and extruded silicone material. Specific sequences including water and silicone suppression are essential for distinguishing rupture from other pathologies and artifacts. Magnetic resonance imaging provides valuable information about the integrity of silicone implants and associated complications.

Magnetic Resonance (MR) Defecography

Science.gov (United States)

... to a CD or uploaded to a digital cloud server. Magnetic resonance (MR) defecography is a special ... with you. top of page What are the benefits vs. risks? Benefits MR defecography helps assess pelvic ...

Fetal abdominal magnetic resonance imaging

International Nuclear Information System (INIS)

Brugger, Peter C.; Prayer, Daniela

2006-01-01

This review deals with the in vivo magnetic resonance imaging (MRI) appearance of the human fetal abdomen. Imaging findings are correlated with current knowledge of human fetal anatomy and physiology, which are crucial to understand and interpret fetal abdominal MRI scans. As fetal MRI covers a period of more than 20 weeks, which is characterized not only by organ growth, but also by changes and maturation of organ function, a different MR appearance of the fetal abdomen results. This not only applies to the fetal intestines, but also to the fetal liver, spleen, and adrenal glands. Choosing the appropriate sequences, various aspects of age-related and organ-specific function can be visualized with fetal MRI, as these are mirrored by changes in signal intensities. Knowledge of normal development is essential to delineate normal from pathological findings in the respective developmental stages

Fetal abdominal magnetic resonance imaging

Energy Technology Data Exchange (ETDEWEB)

Brugger, Peter C. [Center of Anatomy and Cell Biology, Integrative Morphology Group, Medical University of Vienna, Waehringerstrasse 13, 1090 Vienna (Austria)]. E-mail: peter.brugger@meduniwien.ac.at; Prayer, Daniela [Department of Radiology, Medical University of Vienna, Waehringerguertel 18-20, 1090 Vienna (Austria)

2006-02-15

This review deals with the in vivo magnetic resonance imaging (MRI) appearance of the human fetal abdomen. Imaging findings are correlated with current knowledge of human fetal anatomy and physiology, which are crucial to understand and interpret fetal abdominal MRI scans. As fetal MRI covers a period of more than 20 weeks, which is characterized not only by organ growth, but also by changes and maturation of organ function, a different MR appearance of the fetal abdomen results. This not only applies to the fetal intestines, but also to the fetal liver, spleen, and adrenal glands. Choosing the appropriate sequences, various aspects of age-related and organ-specific function can be visualized with fetal MRI, as these are mirrored by changes in signal intensities. Knowledge of normal development is essential to delineate normal from pathological findings in the respective developmental stages.

First national meeting of magnetic resonance and hyperfine interactions

International Nuclear Information System (INIS)

1985-07-01

Works performed at CNEA's: Magnetic Resonance Division; Moessbauer Spectroscopy; Solid State Physics Division; Nuclear magnetic Resonance Laboratory and Theoretical Physics Group; Mossbauer Spectroscopy Group; Nuclear Quadrupole Resonance; Physics and Materials Group; Perturbed Angular Correlation and Moessbauer Spectroscopy and Physics Department. (M.E.L.) [es

Deep-level defects in semiconductors: studies by magnetic resonance

International Nuclear Information System (INIS)

Ammerlaan, C.A.J.

1983-01-01

This work is divided into two parts. In the first one, the following topics are discussed: paramagnetic centers in semiconductors, principles of magnetic resonance, spin-Hamiltonian, g-tensor, hyperfine interaction, magnetic resonance spectrometer. In the second part it is dicussed defects studied by magnetic resonance including vacancy and divacancy in silicon, iron in silicon, nitrogen in diamond and antisite defects in III-V compounds. (A.C.A.S.) [pt

CT and magnetic resonance imaging finding of lipomatous hemanioperisytoma of skull base: A case report

Energy Technology Data Exchange (ETDEWEB)

Park, Hee Girl; Yu, In Kyu; Kim, Han Kyu; Kim, Seung Min; Kang, Dong Wook [Eulji University Hospital, Daejeon (Korea, Republic of)

2013-07-15

Lipomatous hemangiopericytoma (LHPC) is recently recognized as a rare hemangiopericytoma variant. To our knowledge, imaging features of LHPC involving skull base have not yet been reported. We present the imaging features of LHPC of skull base in a 44-year-old female, along with a literature review CT and magnetic resonance imagings showed well-enhanced fatty issues containing temporal skull base masses, with pressure bony erosions.

An introduction to magnetic resonance in medicine. 2. rev. ed.

International Nuclear Information System (INIS)

Rinck, P.A.; Muller, R.N.; Petersen, S.B.

1990-01-01

The second edition of this introduction to magnetic resonance in medicine is published five years after the first. During these years, magnetic resonance has established itself as a leading diagnostic modality in medicine. With the introduction of fast imaging methods and contrast agents, magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) have become even more complicated and complex than before. The purpose of this introduction to biomedical MRI and MRS is to give the readers a basic knowledge that will make it possible for them to pursue studies of their own and to cope with some of the most common problems such as image artifacts or patient questions concerning possible hazards of magnetic resonance. (orig./MG) With 99 figs., 11 tabs

Controlling interactions between highly magnetic atoms with Feshbach resonances.

Science.gov (United States)

Kotochigova, Svetlana

2014-09-01

This paper reviews current experimental and theoretical progress in the study of dipolar quantum gases of ground and meta-stable atoms with a large magnetic moment. We emphasize the anisotropic nature of Feshbach resonances due to coupling to fast-rotating resonant molecular states in ultracold s-wave collisions between magnetic atoms in external magnetic fields. The dramatic differences in the distribution of resonances of magnetic (7)S3 chromium and magnetic lanthanide atoms with a submerged 4f shell and non-zero electron angular momentum is analyzed. We focus on dysprosium and erbium as important experimental advances have been recently made to cool and create quantum-degenerate gases for these atoms. Finally, we describe progress in locating resonances in collisions of meta-stable magnetic atoms in electronic P-states with ground-state atoms, where an interplay between collisional anisotropies and spin-orbit coupling exists.

Resonant Magnetization Tunneling in Molecular Magnets: Where is the Inhomogeneous Broadening?

Science.gov (United States)

Friedman, Jonathan R.; Sarachik, M. P.

1998-03-01

Since the discovery(J. R. Friedman, et al., Phys. Rev. Lett. 76), 3830 (1996) of resonant magnetization tunneling in the molecular magnet Mn_12 there has been intense research into the underlying mechanism of tunneling. Most current theories( V. Dobrovitski and A. Zvezdin, Europhys. Lett. 38), 377 (1997); L. Gunther, Europhys. Lett. 39, 1 (1997); D Garanin and E. Chudnovsky, Phys. Rev. B 56, 11102 (1997). suggest that a local internal (hyperfine or dipole) field transverse to the easy magnetization axis induces tunneling. These theories predict a resonance width orders of magnitude smaller than that actually observed. This discrepancy is attributed to inhomogeneous broadening of the resonance by the random internal fields. We present a detailed study of the tunnel resonance lineshape and show that it is Lorentzian, suggesting it has a deeper physical origin. Since the hyperfine fields are believed to be comparable to the observed width, it is surprising that there is no Gaussian broadening.

Surgical evaluation of magnetic resonance imaging findings in piriformis muscle syndrome

International Nuclear Information System (INIS)

Pecina, Hrvoje Ivan; Boric, Igor; Smoljanovic, Tomislav; Pecina, Marko; Duvancic, Davor

2008-01-01

The objective of this study was to evaluate the accuracy of magnetic resonance imaging (MRI) in the diagnosis of the piriformis muscle syndrome (PMS). In ten patients, seven female and three male, with a long history of clinical symptoms of the PMS, an MRI was performed as the last preoperative diagnostic tool. All patients were imaged using 2T MR system (Elscint, Haifa, Israel). Axial and coronal spin-echo, fast spin-echo (FSE), and fat-suppressed FSE-weighted images were made through the pelvic region with 3-mm section thickness and a 0.5-mm gap to show the whole piriformis muscle and the course of sciatic nerve on its way out of the pelvis. A routine examination also included axial fast spin-echo T2, three-dimensional gradient echo. In seven cases, an MRI abnormality for the PMS was found. In two women, the MRI demonstrated a bigastric appearance of the piriformis muscle with a tendinous portion between the muscle heads and the course of the common peroneal nerve through the muscle between the tendinous portions of the muscle. In one female patient, the common peroneal nerve passed through the hypertrophied piriformis muscle. In four patients, the MRI showed a hypertrophied aspect of the piriformis muscle and an anteriorly displaced sciatic nerve. All MRI findings were confirmed surgically. In three patients, no apparent abnormalities could be observed, but after a surgical treatment, i.e., a tenotomy of the piriformis muscle and neurolysis of the sciatic nerve, all symptoms disappeared. In piriformis muscle syndrome, MRI may demonstrate signal abnormalities of the sciatic nerve as well as its relationship with the normal and abnormal piriformis muscle. (orig.)

Magnetic Resonance Imaging Verification of a Case of Sacrococcygeal Teratoma

OpenAIRE

Dedushi, Kreshnike; Kabashi, Serbeze; Mucaj, Sefedin; Ramadani, Naser; Hoxhaj, Astrit; Shatri, Jeton; Hasbahta, Gazmend

2016-01-01

Although rare, sacrococcygeal teratoma is the most common congenital neoplasm, occurring in 1 in 40,000 infants. Approximately 75% of affected infants are female. The aim of the present study was to correlate ultrasonography and magnetic resonance imaging (MRI) findings in patients with fetal sacrococcygeal teratoma. Three pregnant women in 27th week of gestation underwent fetal MRI after ultrasonography examination, with findings suggestive for fetal sacrococcygeal teratoma. Tumor size, loca...

Diffusion-Weighted Magnetic Resonance Imaging in Rhombencephalitis due to Listeria monocytogenes

Energy Technology Data Exchange (ETDEWEB)

Hatipoglu, H.G.; Onbasioglu Gurbuz, M.; Sakman, B.; Yuksel, E. [Dept. of Radiology, Ankara Numune Education and Research Hospital, Ankara (Turkey)

2007-04-15

We present diffusion-weighted imaging findings of a case of rhombencephalitis due to Listeria monocytogenes. It is a rare, life-threatening disorder. The diagnosis is difficult by clinical findings only. In this report, we aim to draw attention to the role of conventional and diffusion-weighted magnetic resonance imaging findings. To our knowledge, this is the first case report in the literature with apparent diffusion coefficient values of diseased brain parenchyma.

SQUID-detected magnetic resonance imaging in microtesla magnetic fields

International Nuclear Information System (INIS)

McDermott, Robert; Kelso, Nathan; Lee, SeungKyun; Moessle, Michael; Mueck, Michael; Myers, Whittier; Haken, Bernard ten; Seton, H.C.; Trabesinger, Andreas H.; Pines, Alex; Clarke, John

2003-01-01

We describe studies of nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI) of liquid samples at room temperature in microtesla magnetic fields. The nuclear spins are prepolarized in a strong transient field. The magnetic signals generated by the precessing spins, which range in frequency from tens of Hz to several kHz, are detected by a low-transition temperature dc SQUID (Superconducting QUantum Interference Device) coupled to an untuned, superconducting flux transformer configured as an axial gradiometer. The combination of prepolarization and frequency-independent detector sensitivity results in a high signal-to-noise ratio and high spectral resolution (∼1 Hz) even in grossly inhomogeneous magnetic fields. In the NMR experiments, the high spectral resolution enables us to detect the 10-Hz splitting of the spectrum of protons due to their scalar coupling to a 31P nucleus. Furthermore, the broadband detection scheme combined with a non-resonant field-reversal spin echo allows the simultaneous observation of signals from protons and 31P nuclei, even though their NMR resonance frequencies differ by a factor of 2.5. We extend our methodology to MRI in microtesla fields, where the high spectral resolution translates into high spatial resolution. We demonstrate two-dimensional images of a mineral oil phantom and slices of peppers, with a spatial resolution of about 1 mm. We also image an intact pepper using slice selection, again with 1-mm resolution. In further experiments we demonstrate T1-contrast imaging of a water phantom, some parts of which were doped with a paramagnetic salt to reduce the longitudinal relaxation time T1. Possible applications of this MRI technique include screening for tumors and integration with existing multichannel SQUID systems for brain imaging

Magnetic resonance of field-frozen and zero-field-frozen magnetic fluids

International Nuclear Information System (INIS)

Pereira, A.R.; Pelegrini, F.; Neto, K. Skeff; Buske, N.; Morais, P.C.

2004-01-01

In this study magnetic resonance was used to investigate magnetic fluid samples frozen under zero and non-zero (15 kG) external fields. The magnetite-based sample containing 2x10 17 particle/cm 3 was investigated from 100 to 400 K. Analysis of the temperature dependence of the resonance field revealed bigger magnetic structures in the frozen state than in the liquid phase. Also, differences in the mesoscopic organization in the frozen state may explain the data obtained from samples frozen under zero and non-zero fields

Capacitor-based detection of nuclear magnetization: nuclear quadrupole resonance of surfaces.

Science.gov (United States)

Gregorovič, Alan; Apih, Tomaž; Kvasić, Ivan; Lužnik, Janko; Pirnat, Janez; Trontelj, Zvonko; Strle, Drago; Muševič, Igor

2011-03-01

We demonstrate excitation and detection of nuclear magnetization in a nuclear quadrupole resonance (NQR) experiment with a parallel plate capacitor, where the sample is located between the two capacitor plates and not in a coil as usually. While the sensitivity of this capacitor-based detection is found lower compared to an optimal coil-based detection of the same amount of sample, it becomes comparable in the case of very thin samples and even advantageous in the proximity of conducting bodies. This capacitor-based setup may find its application in acquisition of NQR signals from the surface layers on conducting bodies or in a portable tightly integrated nuclear magnetic resonance sensor. Copyright © 2010 Elsevier Inc. All rights reserved.

The galenic venous system: Surgical anatomy and its angiographic and magnetic resonance venographic correlations

International Nuclear Information System (INIS)

Kilic, Tuerker; Ozduman, Koray; Cavdar, Safiye; Oezek, M. Memet; Pamir, M. Necmettin

2005-01-01

Objective: This study aims at evaluating the adequacy of digital subtraction angiography and magnetic resonance venography in imaging of the galenic venous system for surgical planning of approaches to the pineal region. Anatomical dissections were carried out in 10 cadavers of several age groups and these were compared to imaging findings in 10 living subjects. Methods: The presence or absence of 10 predetermined veins or vein groupings belonging to the galenic venous system were prospectively analyzed in 10 cadaver dissections and imaging findings of 10 age matched human subjects. The studied vessels were the vein of galen, the internal cerebral veins, both basal vein of Rosenthals, internal occipital vein, occipitotemporal veins, precentral cerebellar veins, tectal veins, pineal veins, superior vermian veins (including superior cerebellar veins (SCVs)) and posterior pericallosal veins. Each of the subjects had both digital subtraction angiography and magnetic resonance venography studies performed. Diagnostic digital subtraction angiography was performed using the transfemoral route and the venous phase was used for the study. Magnetic resonance venography was performed in 1.5 T MRI equipment using the 2D-TOF sequence. All studies were reported to be normal. Results: There was wide variation in the anatomy of the galenic venous system. There were interpersonal, intrapersonal and age related variations. Both the digital subtraction angiography and the magnetic resonance venography were efficient at demonstrating large veins. However, smaller veins were less readily demonstrated in either study. The general sensitivities of the digital subtraction angiography and the magnetic resonance venography for the galenic venous system were 45.5% and 32.5%, respectively. Surgically important veins were missed in most studies. Conclusions: Anatomically, the galenic venous system is highly variable. This variability is caused by interpersonal, intrapersonal and age related

The galenic venous system: Surgical anatomy and its angiographic and magnetic resonance venographic correlations

Energy Technology Data Exchange (ETDEWEB)

Kilic, Tuerker [Marmara University, Department of Neurosurgery, PK 53, Maltepe, 81532 Istanbul (Turkey) and Marmara University, Department of Anatomy, Istanbul (Turkey)]. E-mail: turkilic@tnn.net; Ozduman, Koray [Marmara University, Department of Neurosurgery, PK 53, Maltepe, 81532 Istanbul (Turkey); Cavdar, Safiye [Marmara University, Department of Anatomy, Istanbul (Turkey); Oezek, M. Memet [Marmara University, Department of Neurosurgery, PK 53, Maltepe, 81532 Istanbul (Turkey); Pamir, M. Necmettin [Marmara University, Department of Neurosurgery, PK 53, Maltepe, 81532 Istanbul (Turkey)

2005-11-01

Objective: This study aims at evaluating the adequacy of digital subtraction angiography and magnetic resonance venography in imaging of the galenic venous system for surgical planning of approaches to the pineal region. Anatomical dissections were carried out in 10 cadavers of several age groups and these were compared to imaging findings in 10 living subjects. Methods: The presence or absence of 10 predetermined veins or vein groupings belonging to the galenic venous system were prospectively analyzed in 10 cadaver dissections and imaging findings of 10 age matched human subjects. The studied vessels were the vein of galen, the internal cerebral veins, both basal vein of Rosenthals, internal occipital vein, occipitotemporal veins, precentral cerebellar veins, tectal veins, pineal veins, superior vermian veins (including superior cerebellar veins (SCVs)) and posterior pericallosal veins. Each of the subjects had both digital subtraction angiography and magnetic resonance venography studies performed. Diagnostic digital subtraction angiography was performed using the transfemoral route and the venous phase was used for the study. Magnetic resonance venography was performed in 1.5 T MRI equipment using the 2D-TOF sequence. All studies were reported to be normal. Results: There was wide variation in the anatomy of the galenic venous system. There were interpersonal, intrapersonal and age related variations. Both the digital subtraction angiography and the magnetic resonance venography were efficient at demonstrating large veins. However, smaller veins were less readily demonstrated in either study. The general sensitivities of the digital subtraction angiography and the magnetic resonance venography for the galenic venous system were 45.5% and 32.5%, respectively. Surgically important veins were missed in most studies. Conclusions: Anatomically, the galenic venous system is highly variable. This variability is caused by interpersonal, intrapersonal and age related

Magnetic Resonance Imaging of Liver Metastasis.

Science.gov (United States)

Karaosmanoglu, Ali Devrim; Onur, Mehmet Ruhi; Ozmen, Mustafa Nasuh; Akata, Deniz; Karcaaltincaba, Musturay

2016-12-01

Liver magnetic resonance imaging (MRI) is becoming the gold standard in liver metastasis detection and treatment response assessment. The most sensitive magnetic resonance sequences are diffusion-weighted images and hepatobiliary phase images after Gd-EOB-DTPA. Peripheral ring enhancement, diffusion restriction, and hypointensity on hepatobiliary phase images are hallmarks of liver metastases. In patients with normal ultrasonography, computed tomography (CT), and positron emission tomography (PET)-CT findings and high clinical suspicion of metastasis, MRI should be performed for diagnosis of unseen metastasis. In melanoma, colon cancer, and neuroendocrine tumor metastases, MRI allows confident diagnosis of treatment-related changes in liver and enables differential diagnosis from primary liver tumors. Focal nodular hyperplasia-like nodules in patients who received platinum-based chemotherapy, hypersteatosis, and focal fat can mimic metastasis. In cancer patients with fatty liver, MRI should be preferred to CT. Although the first-line imaging for metastases is CT, MRI can be used as a problem-solving method. MRI may be used as the first-line method in patients who would undergo curative surgery or metastatectomy. Current limitation of MRI is low sensitivity for metastasis smaller than 3mm. MRI fingerprinting, glucoCEST MRI, and PET-MRI may allow simpler and more sensitive diagnosis of liver metastasis. Copyright © 2016 Elsevier Inc. All rights reserved.

Contribution of magnetic resonance imaging to the diagnosis of eosinophilic granuloma in children

International Nuclear Information System (INIS)