• Title/Summary/Keyword: High resolution MRI

Search Result 129, Processing Time 0.019 seconds

Review of Recent Advancement of Ultra High Field Magnetic Resonance Imaging: from Anatomy to Tractography

  • Cho, Zang-Hee
    • Investigative Magnetic Resonance Imaging
    • /
    • v.20 no.3
    • /
    • pp.141-151
    • /
    • 2016
  • Purpose: Advances of magnetic resonance imaging (MRI), especially that of the Ultra-High Field (UHF) MRI will be reviewed. Materials and Methods: Diffusion MRI data was obtained from a healthy adult young male of age 30 using a 7.0T research MRI scanner (Magnetom, Siemens) with 40 mT/m maximum gradient field. The specific imaging parameters used for the data acquisition were a single shot DW echo planar imaging. Results: Three areas of the imaging experiments are focused on for the study, namely the anatomy, angiography, and tractography. Conclusion: It is envisioned that, in near future, there will be more 7.0T MRIs for brain research and explosive clinical application research will also be developed, for example in the area of connectomics in neuroscience and clinical neurology and neurosurgery.

Usefulness of High Resolution MRI in Confirmation of Mechanism:A Case Report (척추동맥폐색의 기전 확인에서 고해상도MRI의 유용성:증례 보고)

  • Hur, Wook;Kang, Hyun Goo
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.19 no.7
    • /
    • pp.239-244
    • /
    • 2018
  • Both arterial dissection and atherosclerosis are major causes of cerebral infarction and appear to be occlusion or stenosis in magnetic resonance angiography(MRA) and computed tomographic angiography(CTA). But there are differences in treatment because they have different mechanisms. Recently, as high resolution magnetic resonance image(HR-MRI) develops, the image of blood vessel wall can be confirmed non-invasively. Though HR-MRI has become a very useful method for patients with suspected arterial dissection, differential diagnosis of the two diseases has not yet been fully established due to differences in the findings according to stages of arterial dissection and atherosclerosis. We investigated the differences between vertebral artery dissection and atherosclerosis through HR-MRI in two patients and confirmed the diagnosis by CTA follow-up. In addition to the previously established diagnostic criteria, we determined that the long and severe stenosis and recanalization suggest arterial dissection. Characteristics of arterial dissection confirmed by HR-MR and additional studies will be helpful for the treatment.

Compressed Sensing Based Dynamic MR Imaging: A Short Survey (Compressed Sensing 기법을 이용한 Dynamic MR Imaging)

  • Jung, Hong;Ye, Jong-Chul
    • Journal of the Institute of Electronics Engineers of Korea SP
    • /
    • v.46 no.5
    • /
    • pp.25-31
    • /
    • 2009
  • The recently developed sampling theory, "compressed sensing" is gathering huge interest in MR reconstruction area because of its feasibility of high spatio-temporal resolution of dynamic MRI which has been limited in conventional methods based on Nyquist sampling theory. Since dynamic MRI usually has high redundant information along temporal direction, this can be very sparsely represented in most of cases. Therefore, compressed sensing that exploits the sparsity of unknown images can be effectively applied in most of dynamic MRI. This review article briefly introduces currently proposed compressed sensing based dynamic MR imaging algorithms and other methods exploiting sparsity. By comparing them with conventional methods, you may have insight how the compressed sensing based methods can impact nearly every area of clinical dynamic MRI.

Imaging of the Brachial Plexus (상완신경총의 영상)

  • Suh, Kyung-Jin;Lee, Jeong-Hyun;Lee, Gyung Kyu
    • Investigative Magnetic Resonance Imaging
    • /
    • v.11 no.2
    • /
    • pp.119-126
    • /
    • 2007
  • MR (magnetic resonance) imaging of the brachial plexus is challenging because of the complex and tangled anatomy of the brachial plexus and the multifariouness of pathologies that can put on it. Improvements in imaging techniques, including the availability of high resolution MR image systems and high channels multidetector computed tomography (CT), have led to more accurate diagnoses and improved serve for treatment planning. For the purpose of imaging and treatment of the brachioplexopathy, it is considerate to divide traumatic and nontraumatic diseases affecting the brachial plexus. MRI is the current gold standard imaging modality for nontraumatic brachial plexopathy. CT myelography is the preferred for the diagnosis of nerve root avulsions affecting the brachial plexus. Other modalities, such as CT, ultrasonography and positron emission tomography, have a limited role in the evaluation of brachial plexus pathology. High-quality, high-resolution MRI remains the main tool for imaging the brachial plexopathy.

  • PDF

High-resolution magnetic resonance imaging of teeth and periodontal tissues using a microscopy coil

  • Shinya Kotaki;Hiroshi Watanabe;Junichiro Sakamoto;Ami Kuribayashi;Marino Araragi;Hironori Akiyama;Yoshiko Ariji
    • Imaging Science in Dentistry
    • /
    • v.54 no.3
    • /
    • pp.276-282
    • /
    • 2024
  • Purpose: This study aimed to assess the performance of 2-dimensional (2D) imaging with microscopy coils in delineating teeth and periodontal tissues compared with conventional 3-dimensional(3D) imaging on a 3 T magnetic resonance imaging (MRI) unit. Materials and Methods: Twelve healthy participants (4 men and 8 women; mean age: 25.6 years; range: 20-52 years) with no dental symptoms were included. The left mandibular first molars and surrounding periodontal tissues were examined using the following 2 sequences: 2D proton density-weighted (PDw) images and 3D enhanced T1 high-resolution isotropic volume excitation (eTHRIVE) images. Two-dimensional MRI images were taken using a 3 T MRI unit and a 47 mm microscopy coil, while 3D MRI imaging used a 3 T MRI unit and head-neck coil. Oral radiologists assessed dental and periodontal structures using a 4-point Likert scale. Inter- and intra-observer agreement was determined using the weighted kappa coefficient. The Wilcoxon signed-rank test was used to compare 2D-PDw and 3D-eTHRIVE images. Results: Qualitative analysis showed significantly better visualization scores for 2D-PDw imaging than for 3D-eTHRIVE imaging (Wilcoxon signed-rank test). 2D-PDw images provided improved visibility of the tooth, root dental pulp, periodontal ligament, lamina dura, coronal dental pulp, gingiva, and nutrient tract. Inter-observer reliability ranged from moderate agreement to almost perfect agreement, and intra-observer agreement was in a similar range. Conclusion: Two-dimensional-PDw images acquired using a 3 T MRI unit and microscopy coil effectively visualized nearly all aspects of teeth and periodontal tissues.

Cranial Nerve Disorders: Clinical Application of High-Resolution Magnetic Resonance Imaging Techniques

  • Lee, Ji Ye;Park, Hye Min;Lee, Boeun;Kim, Ji-hoon
    • Investigative Magnetic Resonance Imaging
    • /
    • v.25 no.4
    • /
    • pp.281-292
    • /
    • 2021
  • Cranial-nerve disorders can be caused by a wide spectrum of diseases, including congenital, inflammatory, and tumorous diseases, and are often encountered in practice. However, the imaging of cranial-nerve disorders is challenging, and understanding the anatomical differences of each region is essential for conducting the best protocols and for detecting subtle changes in cranial nerves during magnetic resonance imaging (MRI) examinations. In this review we discuss which MRI techniques are best for observing normal and pathologic appearance, according to the different regions of the cranial nerves.

Diagnostic Performance of Rectal CT for Staging Rectal Cancer: Comparison with Rectal MRI and Histopathology (직장암 병기결정에서 직장 CT의 진단능: 직장 MRI 및 병리결과와의 비교분석)

  • Seok Yoon Son;Yun Seok Seo;Jeong Hee Yoon;Bo Yun Hur;Jae Seok Bae;Se Hyung Kim
    • Journal of the Korean Society of Radiology
    • /
    • v.84 no.6
    • /
    • pp.1290-1308
    • /
    • 2023
  • Purpose To compare the diagnostic performance of rectal CT with that of high-resolution rectal MRI and histopathology in assessing rectal cancer. Materials and Methods Sixty-seven patients with rectal cancer who underwent rectal CT with rectal distension using sonographic gel and high-resolution MRI were enrolled in this study. The distance from the anal verge/anorectal junction, distance to the mesorectal fascia (MRF), extramural depth (EMD), extramesorectal lymph node (LN) involvement, extramural venous invasion (EMVI), and T/N stages in rectal CT/MRI were analyzed by two gastrointestinal radiologists. The CT findings of 20 patients who underwent radical surgery without concurrent chemoradiotherapy were compared using histopathology. Interclass correlations and kappa statistics were used. Results The distance from the anal verge/anorectal junction showed an excellent intraclass correlation between CT and MRI for both reviewers. For EMD, the distance to the MRF, presence of LNs, extramesorectal LN metastasis, EMVI, T stage, and intermodality kappa or weighted kappa values between CT and MRI showed excellent agreement. Among the 20 patients who underwent radical surgery, T staging, circumferential resection margin involvement, EMVI, and LN metastasis on rectal CT showed acceptable concordance rates with histopathology. Conclusion Dedicated rectal CT may be on par with rectal MRI in providing critical information to patients with rectal cancer.

Experience with 7.0 T MRI in Patients with Supratentorial Meningiomas

  • Song, Sang Woo;Son, Young Don;Cho, Zang-Hee;Paek, Sun Ha
    • Journal of Korean Neurosurgical Society
    • /
    • v.59 no.4
    • /
    • pp.405-409
    • /
    • 2016
  • Meningiomas are typically diagnosed by their characteristic appearance on conventional magnetic resonance imaging (MRI). However, detailed image findings regarding peri- and intra-tumoral anatomical structures, tumor consistency and vascularity are very important in pre-surgical planning and surgical outcomes. At the 7.0 T MRI achieving ultra-high resolution, it could be possible to obtain more useful information in surgical strategy. Four patients who were radiologically diagnosed with intracranial meningioma in 1.5 T MRI underwent a 7.0 T MRI. Three of them underwent surgery afterwards, and one received gamma knife radiosurgery. In our study, the advantages of 7.0 T MRI over 1.5 T MRI were a more detailed depiction of the peri- and intra-tumoral vasculature and a clear delineation of tumor-brain interface. In the safety issues, all patients received 7.0 T MRI without any adverse event. One disadvantage of 7.0 T MRI was the reduced image quality of skull base lesions. 7.0 T MRI in patients with meningiomas could provide useful information in surgical strategy, such as the peri-tumoral vasculature and the tumor-brain interface.

Fascicular Involvement of the Median Nerve Trunk in the Upper Arm: Manifestation as Anterior Interosseous Nerve Syndrome With Unique Imaging Features

  • Jae Eun Park;Darryl B. Sneag;Yun Sun Choi;Sung Hoon Oh;SeongJu Choi
    • Korean Journal of Radiology
    • /
    • v.25 no.5
    • /
    • pp.449-458
    • /
    • 2024
  • Selective fascicular involvement of the median nerve trunk above the elbow leading to anterior interosseous nerve (AIN) syndrome is a rare form of peripheral neuropathy. This condition has recently garnered increased attention within the medical community owing to advancements in imaging techniques and a growing number of reported cases. In this article, we explore the topographical anatomy of the median nerve trunk and the clinical features associated with AIN palsy. Our focus extends to unique manifestations captured through MRI and ultrasonography (US) studies, highlighting noteworthy findings, such as nerve fascicle swelling, incomplete constrictions, hourglass-like constrictions, and torsions, particularly in the posterior/posteromedial region of the median nerve. Surgical observations have further enhanced the understanding of this complex neuropathic condition. High-resolution MRI not only reveals denervation changes in the AIN and median nerve territories but also illuminates these alterations without the presence of compressing structures. The pivotal roles of high-resolution MRI and US in diagnosing this condition and guiding the formulation of an optimal treatment strategy are emphasized.