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Rapid acquisition of magnetic resonance imaging of the shoulder using three-dimensional fast spin echo sequence with compressed sensing. Magn Reson Imaging 2017; 42:152-157. [DOI: 10.1016/j.mri.2017.07.022] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 07/22/2017] [Accepted: 07/23/2017] [Indexed: 11/18/2022]
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Martín Noguerol T, Luna A, Gómez Cabrera M, Riofrio AD. Clinical applications of advanced magnetic resonance imaging techniques for arthritis evaluation. World J Orthop 2017; 8:660-673. [PMID: 28979849 PMCID: PMC5605351 DOI: 10.5312/wjo.v8.i9.660] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Revised: 04/18/2017] [Accepted: 05/05/2017] [Indexed: 02/06/2023] Open
Abstract
Magnetic resonance imaging (MRI) has allowed a comprehensive evaluation of articular disease, increasing the detection of early cartilage involvement, bone erosions, and edema in soft tissue and bone marrow compared to other imaging techniques. In the era of functional imaging, new advanced MRI sequences are being successfully applied for articular evaluation in cases of inflammatory, infectious, and degenerative arthropathies. Diffusion weighted imaging, new fat suppression techniques such as DIXON, dynamic contrast enhanced-MRI, and specific T2 mapping cartilage sequences allow a better understanding of the physiopathological processes that underlie these different arthropathies. They provide valuable quantitative information that aids in their differentiation and can be used as potential biomarkers of articular disease course and treatment response.
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Affiliation(s)
| | - Antonio Luna
- MRI Unit, Clínica Las Nieves, SERCOSA, Health Time, 23007 Jaén, Spain
- Department of Radiology, University Hospitals of Cleveland, Case Western Reserve University, Cleveland, OH 44106, United States
| | | | - Alexie D Riofrio
- Department of Radiology, Duke Regional Hospital, Durham, NC 27710, United States
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Santucci D, Lee SS, Hartman H, Walgampaya S, AlObaidy M, Ramalho M, Dale BM, Semelka RC. Comparison of Cartesian and radial acquisition on short-tau inversion recovery (STIR) sequences in breast MRI. Radiol Bras 2017; 50:216-223. [PMID: 28894328 PMCID: PMC5586511 DOI: 10.1590/0100-3984.2015-0197] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Objective The purpose of this study was to compare two short-tau inversion recovery
(STIR) sequences, Cartesian and radial (BLADE) acquisitions, for breast
magnetic resonance imaging (MRI) examinations. Materials and Methods Ninety-six women underwent 1.5 T breast MRI exam (48 Cartesian and 48 BLADE).
Qualitative analysis including image artifacts, image quality,
fat-suppression, chest-wall depiction, lesion detection, lymph node
depiction and overall impression were evaluated by three blinded readers.
Signal to noise ratios (SNRs) were calculated. Cronbach's alpha test was
used to assess inter-observer agreement. Subanalyses of image quality,
chest-wall depiction and overall impression in 15 patients with implants and
image quality in 31 patients with clips were correlated using Pearson test.
Wilcoxon rank sum test and t-test were performed. Results Motion artifacts were present in 100% and in 0% of the Cartesian and the
BLADE exams, respectively. Chemical-shift artifacts were present in 8% of
the Cartesian exams. Flow artifacts were more frequent on BLADE. BLADE
sequence was statistically superior to Cartesian for all qualitative
features (p < 0.05) except for fat-suppression
(p = 0.054). In the subanalysis, BLADE was superior for
implants and clips (p < 0.05). SNR was statistically
greater for BLADE (48.35 vs. 16.17). Cronbach ranged from 0.502 to
0.813. Conclusion BLADE appears to be superior to Cartesian acquisition of STIR imaging as
measured by improved image quality, fewer artifacts, and improved chest wall
and lymph node depiction.
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Affiliation(s)
- Domiziana Santucci
- MD, Department of Radiological Sciences, University of Rome "Sapienza", Rome, Italy, Department of Radiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Sheila S Lee
- MD, Department of Radiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Heidi Hartman
- MD, Department of Radiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Shyama Walgampaya
- MD, Department of Radiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Mamdoh AlObaidy
- MD, Department of Radiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Miguel Ramalho
- MD, Department of Radiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Brian M Dale
- PhD, Siemens Medical Solutions, Inc., Morrisville, NC, USA
| | - Richard C Semelka
- MD, Department of Radiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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104
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Sung S, Kim HS, Kwon JW. MRI assessment of sacroiliitis for the diagnosis of axial spondyloarthropathy: comparison of fat-saturated T2, STIR and contrast-enhanced sequences. Br J Radiol 2017; 90:20170090. [PMID: 28749173 DOI: 10.1259/bjr.20170090] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
OBJECTIVE To evaluate whether there are significant differences between contrast-enhanced fat-saturated T1 weighted imaging and non-enhanced fat-suppression imaging for diagnosing sacroiliitis in patients with inflammatory back pain. METHODS 92 patients, consisting of 46 males and 46 females (mean age: 34 years; range: 15-63 years), who met at least 4 out of 5 Assessment in SpondyloArthritis international Society criteria for inflammatory low back pain were enrolled in this study. All patients underwent MRI consisting of a coronal short tau inversion recovery (STIR) sequence, axial fat-saturated T2 weighted imaging (T2FS), and coronal and axial contrast-enhanced fat-saturated T1 weighted imaging (c & a T1CE). Two observers independently reviewed an image set of coronal STIR with axial T2FS, and an image set of c & a T1CE, at separate times. The degree of bone marrow edema and osteitis was evaluated from each image set. A decision for sacroiliitis positivity for each image set was made based on the findings. The presence of additional active inflammatory findings of spondyloarthropathy such as synovitis, enthesitis and capsulitis were also evaluated. RESULTS Interobserver and intersequence agreement for the degree of bone marrow edema and osteitis were good or excellent in all quadrants. Cohen's kappa coefficients for sacroiliitis positivity between the two observers were 0.978 and 0.956, and Cohen's kappa coefficients between the two image sets for each observer were 0.892 and 0.870, respectively. The intersequence agreement of additional active inflammatory findings was substantial, and the interobserver agreement was almost perfect or substantial. CONCLUSION STIR with T2FS image is comparable to T1CE image for diagnosing spondyloarthropathy. T1CE images may have a role in evaluating additional active inflammatory findings of spondyloarthropathy such as synovitis, enthesitis and capsulitis. Advances in knowledge: Coronal STIR with axial T2FS may be sufficient for diagnosis spondyloarthropathy without use of contrast administration.
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Affiliation(s)
- Siyoun Sung
- 1 Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine , Seoul , Republic of Korea
| | - Hyun Su Kim
- 1 Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine , Seoul , Republic of Korea
| | - Jong Won Kwon
- 1 Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine , Seoul , Republic of Korea
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105
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Berkowitz JL, Potter HG. Advanced MRI Techniques for the Hip Joint: Focus on the Postoperative Hip. AJR Am J Roentgenol 2017; 209:534-543. [PMID: 28537800 PMCID: PMC5578463 DOI: 10.2214/ajr.16.17789] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
OBJECTIVE Imaging the hip joint with optimized MRI protocol parameters provides the radiologist with the ability to reliably diagnose complex hip abnormalities. The institution of appropriate metal artifact reduction techniques and dedicated sequences can enhance visualization of the periprosthetic bone and soft tissues and allow improved detection of the more frequently encountered total hip arthroplasty-related conditions, such as mechanical loosening, polyethylene wear, and adverse local tissue reactions. CONCLUSION Finally, through the use of dynamic contrast-enhanced MRI, abnormal femoral head perfusion, one of the most common complications associated with femoral neck fracture internal fixation, can be detected before the development of femoral head osteonecrosis, subchondral collapse, and secondary osteoarthritis. Thus, through the institution of the techniques described in this review article, the challenges associated with MRI of hip arthroplasty and instrumentation can be overcome, allowing for the diagnosis of common associated complications.
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Affiliation(s)
- Jennifer L Berkowitz
- 1 Department of Radiology and Imaging, Hospital for Special Surgery, 535 East 70th St, New York, NY 10021
| | - Hollis G Potter
- 1 Department of Radiology and Imaging, Hospital for Special Surgery, 535 East 70th St, New York, NY 10021
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Pezeshk P, Alian A, Chhabra A. Role of chemical shift and Dixon based techniques in musculoskeletal MR imaging. Eur J Radiol 2017; 94:93-100. [DOI: 10.1016/j.ejrad.2017.06.011] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 06/13/2017] [Accepted: 06/14/2017] [Indexed: 12/25/2022]
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Wu W, Miller KL. Image formation in diffusion MRI: A review of recent technical developments. J Magn Reson Imaging 2017; 46:646-662. [PMID: 28194821 PMCID: PMC5574024 DOI: 10.1002/jmri.25664] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2016] [Accepted: 01/25/2017] [Indexed: 12/13/2022] Open
Abstract
Diffusion magnetic resonance imaging (MRI) is a standard imaging tool in clinical neurology, and is becoming increasingly important for neuroscience studies due to its ability to depict complex neuroanatomy (eg, white matter connectivity). Single-shot echo-planar imaging is currently the predominant formation method for diffusion MRI, but suffers from blurring, distortion, and low spatial resolution. A number of methods have been proposed to address these limitations and improve diffusion MRI acquisition. Here, the recent technical developments for image formation in diffusion MRI are reviewed. We discuss three areas of advance in diffusion MRI: improving image fidelity, accelerating acquisition, and increasing the signal-to-noise ratio. LEVEL OF EVIDENCE 5 Technical Efficacy: Stage 1 J. MAGN. RESON. IMAGING 2017;46:646-662.
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Affiliation(s)
- Wenchuan Wu
- FMRIB Centre, Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUK
| | - Karla L. Miller
- FMRIB Centre, Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUK
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Variance in infra-patellar fat pad volume: Does the body mass index matter?—Data from osteoarthritis initiative participants without symptoms or signs of knee disease. Ann Anat 2017; 213:19-24. [DOI: 10.1016/j.aanat.2017.04.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2016] [Revised: 03/05/2017] [Accepted: 04/12/2017] [Indexed: 11/18/2022]
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109
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Advanced MRI Techniques of the Shoulder Joint: Current Applications in Clinical Practice. AJR Am J Roentgenol 2017; 209:544-551. [PMID: 28829170 DOI: 10.2214/ajr.17.17945] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVE We are fortunate to live in a time when real advances in medicine are happening at an increasingly rapid pace. This is especially true in the field of radiology, and keeping abreast of these advances is one of the main challenges of clinical practice. Traditionally, cutting edge techniques in our field have been researched and validated at major academic medical centers before slowly making their way into the armamentarium of routine clinical practice. However, the improved ability to communicate and disseminate information in our modern age has facilitated more rapid implementation of new techniques to allow us to better serve our patients. CONCLUSION As such, this article aims to review the current standards for MRI of the shoulder used in routine practice. Furthermore, we will discuss some of the most recent advances in shoulder MRI, with particular emphasis on the applicability of an additional axial 3D T1-weighted FLASH sequence with Dixon-based water-fat separation in routine clinical practice that can be useful in characterizing several commonly encountered pathologic processes of the shoulder joint.
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Park HJ, Lee SY, Choi SH, Hong HP, Choi YJ, Kim MS. Reduced metallic artefacts in 3 T knee MRI using fast spin-echo multi-point Dixon compared to fast spin-echo T2-weighted sequences. Clin Radiol 2017; 72:996.e1-996.e6. [PMID: 28807564 DOI: 10.1016/j.crad.2017.07.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 06/18/2017] [Accepted: 07/06/2017] [Indexed: 10/19/2022]
Abstract
AIM To compare multi-point Dixon magnetic resonance imaging (MRI) and fast spin-echo (FSE) T2-weighted imaging (WI) with regard to the size of metallic artefacts when imaging the knee joint. MATERIALS AND METHODS A total of 42 patients who underwent anterior cruciate ligament (ACL) reconstruction and follow-up imaging with 3 T MRI using the multi-point Dixon technique was included in this retrospective study. The maximal distance of the image distortion area around the metallic artefact was measured (interference screw of femoral tunnel area) on sagittal images of both FSE T2WI (T2WI and fat-suppressed [FS] T2WI) and multi-point Dixon (water only image and in-phase image) sequences. The maximal distance of the image distortion were compared using paired t-tests across the image sequences (multi-point Dixon water only image versus FS T2WI and multi-point Dixon in-phase image versus T2WI). RESULTS The mean distance of the image distortion from metallic artefacts regardless of the image sequence ranged from 16.6 mm to 24.5 mm (Table 2). The mean distances measured by two readers on multi-point Dixon (water only image) sequences were significantly shorter than those in FS T2WI sequences (p<0.001). In contrast, the mean distances measured by two readers on multi-point Dixon (in-phase image) sequences did not differ from those of T2WI (p>0.05) sequences. CONCLUSION The water-only image of multi-point Dixon technique reduces the amount of metallic artefacts compared to that in FS FSE T2WI sequences; however, the metallic artefacts were not significantly different between in-phase images of multi-point Dixon and FSE T2WI.
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Affiliation(s)
- H J Park
- Department of Radiology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - S Y Lee
- Department of Radiology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - S H Choi
- Department of Radiology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - H P Hong
- Department of Radiology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Y J Choi
- Department of Radiology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
| | - M S Kim
- Department of Radiology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
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Mavroidis P, Boci N, Kostopoulos S, Ninos C, Glotsos D, Oikonomou G, Bakas A, Roka V, Sakkas GK, Tsagkalis A, Chatzigeorgiou V, Batsikas G, Zaimis G, Cavouras D, Lavdas E. Investigation of the Possibility to Reduce Susceptibility Artifacts in MRI Knee Examination. J Med Biol Eng 2017. [DOI: 10.1007/s40846-017-0260-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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112
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Which MR sequences should we use for the reliable detection and localization of bone marrow edema in spondyloarthritis? Radiol Med 2017; 122:752-760. [PMID: 28593478 PMCID: PMC5596031 DOI: 10.1007/s11547-017-0778-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 05/25/2017] [Indexed: 12/17/2022]
Abstract
Objectives To assess the diagnostic confidence in detecting and localizing areas of bone marrow edema in the sacroiliac joint of patients with suspected spondyloarthritis using a single-plane method and comparing it with multiplanar unenhanced and enhanced methods. Materials and methods Patients with clinical suspicion of spondyloarthritis undergoing an MRI of the sacroiliac joint were included in this retrospective study. To assess sacroiliitis, three methods were applied: single-plane (i.e., para-coronal STIR alone), multiplanar unenhanced (i.e., para-coronal STIR and para-axial PD-fs), and multiplanar enhanced method (i.e., para-coronal and para-axial post-contrast T1-fs). Two 4-point scales were used to evaluate, respectively, the diagnostic confidence in detection and localization of bone marrow edema. The distribution of certain and uncertain rating according to signal intensity and size of the lesions was also calculated. Results Seventy-four patients met the inclusion criteria. Both multiplanar methods increased the diagnostic confidence in detection (p < 0.001) and localization (p < 0.001) of sacroiliitis; no significant difference occurred between the multiplanar unenhanced and enhanced methods (p = 0.405 and p = 1.00, respectively, for detection and localization). A statistically significant difference between the distributions of certain and uncertain rating for detection based on the size and signal intensity of each lesion emerged (p = 0.006 and p < 0.001, respectively), whereas no statistically significant difference occurred for the confidence of localization (p = 0.452 and p = 0.694, respectively). Conclusions The multiplanar methods increased the diagnostic confidence in detection and localization of sacroiliitis. The absence of a significant difference between the proposed unenhanced and enhanced methods suggests that contrast medium is not mandatory for the detection of sacroiliitis.
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Organji H, Rajabkhah S, Fatehi F. A giant cervicothoracic cord lipoma: an uncommon finding. Acta Neurol Belg 2017; 117:541-543. [PMID: 27670441 DOI: 10.1007/s13760-016-0700-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Accepted: 09/20/2016] [Indexed: 10/20/2022]
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114
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115
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Diagnosis of Internal Derangement of the Knee: Volume Isotropic Turbo Spin-Echo Acquisition MRI With Fat Suppression Versus Without Fat Suppression. AJR Am J Roentgenol 2017; 208:1304-1311. [DOI: 10.2214/ajr.16.17217] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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116
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Klengel A, Stumpp P, Klengel S, Böttger I, Rönisch N, Kahn T. Detection of Traumatic Bone Marrow Lesions after Knee Trauma: Comparison of ADC Maps Derived from Diffusion-weighted Imaging with Standard Fat-saturated Proton Density–weighted Turbo Spin-Echo Sequences. Radiology 2017; 283:469-477. [DOI: 10.1148/radiol.2016160306] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Alexis Klengel
- From the Department of Diagnostic and Interventional Radiology, University Hospital Leipzig, Liebigstr 20, 04103 Leipzig, Germany (A.K., P.S., T.K.); and Department of Radiology, Medical Service Center RadCom, Riesa, Germany (S.K., I.B., N.R.)
| | - Patrick Stumpp
- From the Department of Diagnostic and Interventional Radiology, University Hospital Leipzig, Liebigstr 20, 04103 Leipzig, Germany (A.K., P.S., T.K.); and Department of Radiology, Medical Service Center RadCom, Riesa, Germany (S.K., I.B., N.R.)
| | - Steffen Klengel
- From the Department of Diagnostic and Interventional Radiology, University Hospital Leipzig, Liebigstr 20, 04103 Leipzig, Germany (A.K., P.S., T.K.); and Department of Radiology, Medical Service Center RadCom, Riesa, Germany (S.K., I.B., N.R.)
| | - Ina Böttger
- From the Department of Diagnostic and Interventional Radiology, University Hospital Leipzig, Liebigstr 20, 04103 Leipzig, Germany (A.K., P.S., T.K.); and Department of Radiology, Medical Service Center RadCom, Riesa, Germany (S.K., I.B., N.R.)
| | - Nadja Rönisch
- From the Department of Diagnostic and Interventional Radiology, University Hospital Leipzig, Liebigstr 20, 04103 Leipzig, Germany (A.K., P.S., T.K.); and Department of Radiology, Medical Service Center RadCom, Riesa, Germany (S.K., I.B., N.R.)
| | - Thomas Kahn
- From the Department of Diagnostic and Interventional Radiology, University Hospital Leipzig, Liebigstr 20, 04103 Leipzig, Germany (A.K., P.S., T.K.); and Department of Radiology, Medical Service Center RadCom, Riesa, Germany (S.K., I.B., N.R.)
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Moore MM, Chung T. Review of key concepts in magnetic resonance physics. Pediatr Radiol 2017; 47:497-506. [PMID: 28409253 DOI: 10.1007/s00247-017-3791-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Revised: 11/19/2016] [Accepted: 01/26/2017] [Indexed: 11/25/2022]
Abstract
MR physics can be a challenging subject for practicing pediatric radiologists. Although many excellent texts provide very comprehensive reviews of the field of MR physics at various levels of understanding, the authors of this paper explain several key concepts in MR physics that are germane to clinical practice in a non-rigorous but practical fashion. With the basic understanding of these key concepts, practicing pediatric radiologists can build on their knowledge of current clinical MR techniques and future advances in MR applications. Given the challenges of both the increased need for rapid imaging in non-sedated children and the rapid physiological cardiovascular and respiratory motion in pediatric patients, many advances in complex MR techniques are being applied to imaging these children. The key concepts are as follows: (1) structure of a pulse sequence, (2) k-space, (3) "trade-off triangle" and (4) fat suppression. This review is the first of five manuscripts in a minisymposium on pediatric MR. The authors' goal for this review is to aid in understanding the MR techniques described in the subsequent manuscripts on brain imaging and body imaging in this minisymposium.
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Affiliation(s)
- Michael M Moore
- Department of Radiology, The Pennsylvania State College of Medicine, Penn State Hershey Children's Hospital, Hershey, PA, 17033, USA
| | - Taylor Chung
- Department of Diagnostic Imaging, UCSF Benioff Children's Hospital Oakland, 747 52nd St., Oakland, CA, 94609, USA.
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119
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Housley D, Caine A, Cherubini G, Taeymans O. Evaluation of T2-weighted versus short-tau inversion recovery sagittal sequences in the identification and localization of canine intervertebral disc extrusion with low-field magnetic resonance imaging. Vet Radiol Ultrasound 2017; 58:433-443. [PMID: 28429414 DOI: 10.1111/vru.12500] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 12/23/2016] [Accepted: 01/16/2017] [Indexed: 11/27/2022] Open
Abstract
Sagittal T2-weighted sequences (T2-SAG) are the foundation of spinal protocols when screening for the presence of intervertebral disc extrusion. We often utilize sagittal short-tau inversion recovery sequences (STIR-SAG) as an adjunctive screening series, and experience suggests that this combined approach provides superior detection rates. We hypothesized that STIR-SAG would provide higher sensitivity than T2-SAG in the identification and localization of intervertebral disc extrusion. We further hypothesized that the parallel evaluation of paired T2-SAG and STIR-SAG series would provide a higher sensitivity than could be achieved with either independent sagittal series when viewed in isolation. This retrospective diagnostic accuracy study blindly reviewed T2-SAG and STIR-SAG sequences from dogs (n = 110) with surgically confirmed intervertebral disc extrusion. A consensus between two radiologists found no significant difference in sensitivity between T2-SAG and STIR-SAG during the identification of intervertebral disc extrusion (T2-SAG: 92.7%, STIR-SAG: 94.5%, P = 0.752). Nevertheless, STIR-SAG accurately identified intervertebral disc extrusion in 66.7% of cases where the evaluation of T2-SAG in isolation had provided a false negative diagnosis. Additionally, one radiologist found that the parallel evaluation of paired T2-SAG and STIR-SAG series provided a significantly higher sensitivity than T2-SAG in isolation, during the identification of intervertebral disc extrusion (T2-SAG: 78.2%, paired T2-SAG, and STIR-SAG: 90.9%, P = 0.017). A similar nonsignificant trend was observed when the consensus of both radiologists was taken into consideration (T2-SAG: 92.7%, paired T2-SAG, and STIR-SAG = 97.3%, P = 0.392). We therefore conclude that STIR-SAG is capable of identifying intervertebral disc extrusion that is inconspicuous in T2-SAG, and that STIR-SAG should be considered a useful adjunctive sequence during preliminary sagittal screening for intervertebral disc extrusion in low-field magnetic resonance.
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Affiliation(s)
- Daniel Housley
- Dick White Referrals, Diagnostic Imaging, Newmarket, Cambridgeshire, United Kingdom of Great Britain and Northern Ireland
| | - Abby Caine
- Dick White Referrals, Diagnostic Imaging, Newmarket, Cambridgeshire, United Kingdom of Great Britain and Northern Ireland
| | - Giunio Cherubini
- Dick White Referrals, Diagnostic Imaging, Newmarket, Cambridgeshire, United Kingdom of Great Britain and Northern Ireland
| | - Olivier Taeymans
- Dick White Referrals, Diagnostic Imaging, Newmarket, Cambridgeshire, United Kingdom of Great Britain and Northern Ireland
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Evaluating the utility of a scoring system for lipomas of the cerebellopontine angle. Acta Neurochir (Wien) 2017; 159:739-750. [PMID: 28110401 DOI: 10.1007/s00701-017-3076-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 01/04/2017] [Indexed: 10/20/2022]
Abstract
BACKGROUND Cerebellopontine angle (CPA) lipomas are rare, benign, slow-growing masses. Resections are considered in symptomatic patients who are refractory to targeted medical therapies, but at those stages the lipomas have often reached considerable sizes and encompass critical neurovascular structures. The objective of this study is to develop and to evaluate the utility of a scoring system for CPA lipomas. The hypothesis is that CPA lipomas with lower scores are probably best managed with early surgery. METHODS The PubMed database was searched using relevant terms. Data on patient and lipoma characteristics were extracted and used to design a scoring system. CPA lipomas were stratified by scores with corresponding managements and outcomes analyzed. RESULTS One hundred and seventeen patients with CPA lipomas were identified and 40 CPA lipomas were scored. The remaining CPA lipomas were deficient in data and not scored. No lipomas were scored as 1. Score 2 lipomas (n = 12; 30%) most often underwent serial surveillances (n = 5; 41.6%), with the majority of symptoms remaining unimproved (n = 2; 40%). Patients with score 2 CPA lipomas treated with medical therapies (n = 3; 25%) often experienced symptom resolution (n = 2; 66.6%) (p = 0.0499). Patients with score 2 CPA lipomas undergoing surgical resections (n = 3; 25%) all experienced symptom resolution (n = 3; 100%) (p = 0.0499). Score 3 was most common (n = 16; 40%) and these lipomas were often surgically resected (n = 10; 62.5%). The majority of patients with score 3 CPA lipomas having undergone surgical resections (n = 10; 62.5%) experienced symptom improvement (n = 1; 10%) or resolution (n = 4; 40%). CONCLUSIONS Score 2 CPA lipomas are smaller and would be deemed non-surgical in general practice. However, our data suggest that these lipomas may benefit from either medical therapies or early surgical resections. The advantages of early surgery are maximal resection, decreased surgical morbidity, and improved symptom relief.
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Lipomatous/Extensively Vacuolated Ependymoma with Signet-Ring Cell-Like Appearance: Analysis of a Case with Extensive Literature Review. Case Rep Pathol 2017; 2017:8617050. [PMID: 28286687 PMCID: PMC5329680 DOI: 10.1155/2017/8617050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Accepted: 01/22/2017] [Indexed: 11/18/2022] Open
Abstract
"Lipomatous" and "extensively vacuolated" are descriptive captions that have been used to portray a curious subset of ependymomas distinctively bearing cells with a large vacuole pushing the nucleus to the periphery and, thus, simulating a signet-ring cell appearance. Here, we would like to report the first ependymoma of this kind in a Latin American institution. A 16-year-old boy experienced cephalea during three months. Magnetic resonance imaging scans showed a left paraventricular tumour which corresponded to anaplastic ependymoma. Intriguingly, it was also composed of cells with single or multiple hollow cytoplasmic vacuoles sometimes giving a signet-ring cell-like configuration. Immunolabeling of these showed membrane positivity for GFAP, PS100, and CD99, while Ki-67 expression was null. Ultrastructural examination of retrieved paraffin-embedded tissue showed the presence of scarce microlumina filled with microvilli but failed to demonstrate any content in such optically empty vacuoles as only scant granulofibrillary debris was observed. A schism prevails at present regarding these unusual morphological variants, being either "lipomatous" or "vacuolated" based mainly on the EMA immunoprofile. This, however, is a misappropriate approaching. Could it be that perhaps we are dealing with the same histopathological entity or it may simply happen that fixation and artefacts cannot allow for their proper identification?
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Ünal E, Karaosmanoğlu AD, Akata D, Özmen MN, Karçaaltıncaba M. Invisible fat on CT: making it visible by MRI. Diagn Interv Radiol 2017; 22:133-40. [PMID: 26782156 DOI: 10.5152/dir.2015.15286] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Presence of fat in a lesion significantly narrows the differential diagnosis. Small quantities of macroscopic fat and intracellular fat are invisible on computed tomography (CT) and ultrasonography. Magnetic resonance imaging (MRI) can reveal any fatty change in a lesion and can also differentiate macroscopic fat from intracellular and intravoxel fat. Hypodensity on CT may be a sign of invisible fat and MRI can help to diagnose even minute amounts of fat in liver, pancreas, adrenal, musculoskeletal, and omental pseudolesions and lesions. This article will review the superiority of MRI over CT in demonstrating fat in abdominal lesions.
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Affiliation(s)
- Emre Ünal
- Department of Radiology, Hacettepe University School of Medicine Ankara, Turkey; Department of Radiology, Zonguldak Atatürk State Hospital, Zonguldak, Turkey.
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MRI assessment of bone marrow oedema in the sacroiliac joints of patients with spondyloarthritis: is the SPAIR T2w technique comparable to STIR? Eur Radiol 2017; 27:3669-3676. [DOI: 10.1007/s00330-017-4746-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 01/06/2017] [Accepted: 01/13/2017] [Indexed: 01/19/2023]
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Woo S, Kim SH. Differentiation of Small, Solid Renal Masses: A Pattern Recognition Approach. Semin Ultrasound CT MR 2017; 38:28-36. [DOI: 10.1053/j.sult.2016.08.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Sahin H, Abdullazade S, Sanci M. Mature cystic teratoma of the ovary: a cutting edge overview on imaging features. Insights Imaging 2017; 8:227-241. [PMID: 28105559 PMCID: PMC5359144 DOI: 10.1007/s13244-016-0539-9] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 12/11/2016] [Accepted: 12/16/2016] [Indexed: 01/30/2023] Open
Abstract
Mature cystic teratoma (MCT) is the most common neoplasm of the ovary and includes at least two well- differentiated germ cell layers. Different combinations of mature tissue derivatives with varying arrangements in the tumour cause a wide spectrum of radiological presentation ranging from a purely cystic mass to a complex cystic mass with a considerable solid component. In different imaging modalities, each radiological feature reflects a specific pathologic equivalent that forms because of diverse compositions of histological components. Understanding uncommon findings as well as the classic signs with basic knowledge of pathological equivalents permits a more accurate diagnosis and guides adequate treatment. In this review, radiological features of MCT in different imaging modalities (US, CT, MR imaging) including specific signs and useful radiological artefacts with brief emphasis on pathological basics are discussed. Teaching points • Ovarian mature cystic teratomas (MCTs) have a wide spectrum of radiological presentation. • Each radiological feature of MCT reflects a specific pathologic equivalent. • Understanding radiological signs with basic knowledge of pathology can permit a more accurate diagnosis.
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Affiliation(s)
- Hilal Sahin
- Department of Radiology, Tepecik Training and Research Hospital, 35110, Yenisehir, Izmir, Turkey.
| | - Samir Abdullazade
- Department of Pathology, Tepecik Training and Research Hospital, 35110, Yenisehir, Izmir, Turkey
| | - Muzaffer Sanci
- Department of Gynecologic Oncology, Tepecik Training and Research Hospital, 35110, Yenisehir, Izmir, Turkey
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Liu J, Peters DC, Drangova M. Method of B0 mapping with magnitude-based correction for bipolar two-point Dixon cardiac MRI. Magn Reson Med 2016; 78:1862-1869. [PMID: 27933641 DOI: 10.1002/mrm.26569] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 11/14/2016] [Accepted: 11/14/2016] [Indexed: 12/22/2022]
Abstract
PURPOSE The conventional two-point (2pt) Dixon technique explicitly estimates B0 map by performing phase unwrapping. When signal loss, phase singularity, artifacts, or spatially isolated regions corrupt the measured phase images, this unwrapping-based technique will face difficulty. This work aims to improve the reliability of B0 mapping by performing unwrapping error correction. METHOD To detect the unwrapping-caused phase errors, we determined a magnitude-based fat/water mask and used it as reference to identify pixels being mismatched by the phase-based mask, which was derived from the B0-corrected phase term of the Hermitian product between echoes. Then, we corrected the afore-determined phase error on a region-by-region basis. We tested the developed method with nine patients' data, and the results were compared with a well-established region-growing technique. RESULTS By adding the step to correct unwrapping-caused error, we improved the robustness of B0 mapping, resulting in better fat-water separation when compared with the conventional 2pt and the phasor-based region-growing techniques. CONCLUSION We showed the feasibility of B0 mapping with bipolar 2pt human cardiac data. The software is freely available to the scientific community. Magn Reson Med 78:1862-1869, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Junmin Liu
- Imaging Research Laboratories, Robarts Research Institute, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Dana C Peters
- Department of Radiology and Biomedical Imaging, Yale Medical School, New Haven, Connecticut, USA
| | - Maria Drangova
- Imaging Research Laboratories, Robarts Research Institute, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada.,Department of Medical Biophysics, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
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Fahmy AS, Ibrahim ESH, Osman NF. Spectrally-Presaturated Modulation (SPM): An efficient fat suppression technique for STEAM-based cardiac imaging sequences. Magn Reson Imaging 2016; 37:209-215. [PMID: 27826082 DOI: 10.1016/j.mri.2016.11.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 11/03/2016] [Indexed: 10/20/2022]
Abstract
Stimulated-echo acquisition mode (STEAM) is a key pulse sequences in MRI in general, and in cardiac imaging in particular. Fat suppression is an important feature in cardiac imaging to improve visualization and eliminate off-resonance and chemical-shift artifacts. Nevertheless, fat suppression comes at the expense of reduced temporal resolution and signal-to-noise ratio (SNR). The purpose of this study is to develop an efficient fat suppression method (Spectrally-Presaturated Modulation) for STEAM-based sequences to enable imaging with high temporal-resolution, high SNR, and no increase in scan time. The developed method is based on saturating the fat magnetization prior to applying STEAM modulation; therefore, only the water-content of the tissues is modulated by the sequence, resulting in fat-suppressed images without the need to run the fat suppression module during image acquisition. The potential significance of the proposed method is presented in two STEAM-based cardiac MRI applications: complementary spatial-modulation of magnetization (CSPAMM), and black-blood cine imaging. Phantom and in vivo experiments are conducted to evaluate the developed technique and compare it to the commonly implemented chemical-shift selective (CHESS) and water-excitation using spectral-spatial selective pulses (SSSP) fat suppression techniques. The results from the phantom and in vivo experiments show superior performance of the proposed method compared to the CHESS and SSSP techniques in terms of temporal resolution and SNR. In conclusion, the developed fat suppression technique results in enhanced image quality of STEAM-based images, especially in cardiac applications, where high temporal-resolution is imperative for accurate measurement of functional parameters and improved performance of image analysis algorithms.
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Affiliation(s)
- Ahmed S Fahmy
- Biomedical Engineering Department, Cairo University, Cairo, Egypt
| | | | - Nael F Osman
- Department of Radiology, Johns Hopkins University, Baltimore, USA
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Abstract
Interpreting body MRI cases can seem overwhelming to an uninitiated radiologist. The standard study includes a variety of pulse sequences, the names of which vary depending on the MR vendor. Pulse sequences may be displayed haphazardly on the picture archiving and communication system (PACS), frequently not synchronized with the imaging protocol. Adding to the complexity is the use of different gadolinium-based contrast agents, which may affect the timing and diagnostic yield of each sequence. The following introductory primer for interpreting body MRI cases is meant to create a basic framework for efficiently reviewing body MRI cases to provide high quality interpretations, fully utilizing the diagnostic information of the modality. There are 4 components that need to be mastered when interpreting body MRI cases including: (1) recognizing the key sequences in a basic body MRI protocol, (2) learning how to best display the key pulse sequences on PACS, (3) understanding the technique and clinical utility of each sequence and learning how to utilize sequences to be an "MR Pathologist", and (4) understanding the key features of the different gadolinium based contrast agents.
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van Heijst TCF, van Asselen B, Pijnappel RM, Cloos-van Balen M, Lagendijk JJW, van den Bongard D, Philippens MEP. MRI sequences for the detection of individual lymph nodes in regional breast radiotherapy planning. Br J Radiol 2016; 89:20160072. [PMID: 27164032 DOI: 10.1259/bjr.20160072] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE In regional radiotherapy (RT) for patients with breast cancer, lymph node (LN) targets are delineated on CT, defined by anatomical boundaries. By identifying individual LNs, MRI-based delineations may reduce target volumes and thereby toxicity. We optimized MRI sequences for this purpose. Our aim was to evaluate the techniques for LN delineation in RT planning. METHODS Supine MRI was explored at 1.5 T in RT position (arms in abduction). 5 MRI techniques were optimized in 10 and evaluated in 12 healthy female volunteers. The scans included one T1 weighted (T1w), three T2 weighted (T2w) and a diffusion-weighted imaging (DWI) technique. Quantitative evaluation was performed by scoring LN numbers per volunteer and per scan. Qualitatively, scans were assessed on seven aspects, including LN contrast, anatomical information and insensitivity to motion during acquisition. RESULTS Two T2w fast spin-echo (FSE) methods showed the highest LN numbers (median 24 axillary), high contrast, excellent fat suppression and relative insensitivity to motion during acquisition. A third T2w sequence and DWI showed significantly fewer LNs (14 and 10) and proved unsuitable due to motion sensitivity and geometrical uncertainties. T1w MRI showed an intermediate number of LNs (17), provided valuable anatomical information, but lacked LN contrast. CONCLUSION Explicit LN imaging was achieved, in supine RT position, using MRI. Two T2w FSE techniques had the highest detection rates and were motion insensitive. T1w MRI showed anatomical information. MRI enables direct delineation of individual LNs. ADVANCES IN KNOWLEDGE Our optimized MRI scans enable accurate target definition in MRI-guided regional breast RT and development of personalized treatments.
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Affiliation(s)
| | - Bram van Asselen
- 1 Department of Radiotherapy, University Medical Centre Utrecht, Utrecht, Netherlands
| | - Ruud M Pijnappel
- 2 Department of Radiology, University Medical Centre Utrecht, Utrecht, Netherlands
| | | | - Jan J W Lagendijk
- 1 Department of Radiotherapy, University Medical Centre Utrecht, Utrecht, Netherlands
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130
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Bakhda RN. Specialized Diagnostic Investigations to Assess Ocular Status in Hypertensive Diseases of Pregnancy. Diseases 2016; 4:diseases4020019. [PMID: 28933399 PMCID: PMC5456274 DOI: 10.3390/diseases4020019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2016] [Revised: 03/27/2016] [Accepted: 04/15/2016] [Indexed: 11/16/2022] Open
Abstract
This review describes specialized diagnostic investigations to assess ocular status in hypertensive diseases of pregnancy. Ocular assessment can aid in early detection for prompt multidisciplinary treatment, obstetric intervention and follow-up. The investigations accurately predict the possible causes of blindness in hypertensive diseases of pregnancy. The investigations include fluorescein angiography, ophthalmodynamometry, fluorophotometry, imaging modalities, OCT, ultrasonography, doppler velocimetry and blood chemistry analysis. The review includes a summary of imaging techniques and related recent developments to assess the neuro-ophthalmic aspects of the disease. The imaging modalities have been instrumental in understanding the complex neuropathophysiological mechanisms of eclamptic seizures. The importance of blood chemistry analysis in hypertensive diseases of pregnancy has been emphasized. The investigations have made a significant contribution in improving the standards of antenatal care and reducing maternal and fetal morbidity and mortality.
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Affiliation(s)
- Rahul Navinchandra Bakhda
- Consultant Ophthalmologist, Ex-Resident, M & J Western Regional Institute of Ophthalmology, Ahmedabad 380016, Gujarat, India.
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131
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Chabiniok R, Wang VY, Hadjicharalambous M, Asner L, Lee J, Sermesant M, Kuhl E, Young AA, Moireau P, Nash MP, Chapelle D, Nordsletten DA. Multiphysics and multiscale modelling, data-model fusion and integration of organ physiology in the clinic: ventricular cardiac mechanics. Interface Focus 2016; 6:20150083. [PMID: 27051509 PMCID: PMC4759748 DOI: 10.1098/rsfs.2015.0083] [Citation(s) in RCA: 139] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
With heart and cardiovascular diseases continually challenging healthcare systems worldwide, translating basic research on cardiac (patho)physiology into clinical care is essential. Exacerbating this already extensive challenge is the complexity of the heart, relying on its hierarchical structure and function to maintain cardiovascular flow. Computational modelling has been proposed and actively pursued as a tool for accelerating research and translation. Allowing exploration of the relationships between physics, multiscale mechanisms and function, computational modelling provides a platform for improving our understanding of the heart. Further integration of experimental and clinical data through data assimilation and parameter estimation techniques is bringing computational models closer to use in routine clinical practice. This article reviews developments in computational cardiac modelling and how their integration with medical imaging data is providing new pathways for translational cardiac modelling.
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Affiliation(s)
- Radomir Chabiniok
- Division of Imaging Sciences and Biomedical Engineering, King's College London, St Thomas’ Hospital, London SE1 7EH, UK
- Inria and Paris-Saclay University, Bâtiment Alan Turing, 1 rue Honoré d'Estienne d'Orves, Campus de l'Ecole Polytechnique, Palaiseau 91120, France
| | - Vicky Y. Wang
- Auckland Bioengineering Institute, University of Auckland, 70 Symonds Street, Auckland, New Zealand
| | - Myrianthi Hadjicharalambous
- Division of Imaging Sciences and Biomedical Engineering, King's College London, St Thomas’ Hospital, London SE1 7EH, UK
| | - Liya Asner
- Division of Imaging Sciences and Biomedical Engineering, King's College London, St Thomas’ Hospital, London SE1 7EH, UK
| | - Jack Lee
- Division of Imaging Sciences and Biomedical Engineering, King's College London, St Thomas’ Hospital, London SE1 7EH, UK
| | - Maxime Sermesant
- Inria, Asclepios team, 2004 route des Lucioles BP 93, Sophia Antipolis Cedex 06902, France
| | - Ellen Kuhl
- Departments of Mechanical Engineering, Bioengineering, and Cardiothoracic Surgery, Stanford University, 496 Lomita Mall, Durand 217, Stanford, CA 94306, USA
| | - Alistair A. Young
- Auckland Bioengineering Institute, University of Auckland, 70 Symonds Street, Auckland, New Zealand
| | - Philippe Moireau
- Inria and Paris-Saclay University, Bâtiment Alan Turing, 1 rue Honoré d'Estienne d'Orves, Campus de l'Ecole Polytechnique, Palaiseau 91120, France
| | - Martyn P. Nash
- Auckland Bioengineering Institute, University of Auckland, 70 Symonds Street, Auckland, New Zealand
- Department of Engineering Science, University of Auckland, 70 Symonds Street, Auckland, New Zealand
| | - Dominique Chapelle
- Inria and Paris-Saclay University, Bâtiment Alan Turing, 1 rue Honoré d'Estienne d'Orves, Campus de l'Ecole Polytechnique, Palaiseau 91120, France
| | - David A. Nordsletten
- Division of Imaging Sciences and Biomedical Engineering, King's College London, St Thomas’ Hospital, London SE1 7EH, UK
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Weygand J, Fuller CD, Ibbott GS, Mohamed ASR, Ding Y, Yang J, Hwang KP, Wang J. Spatial Precision in Magnetic Resonance Imaging-Guided Radiation Therapy: The Role of Geometric Distortion. Int J Radiat Oncol Biol Phys 2016; 95:1304-16. [PMID: 27354136 DOI: 10.1016/j.ijrobp.2016.02.059] [Citation(s) in RCA: 113] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 02/05/2016] [Accepted: 02/25/2016] [Indexed: 12/11/2022]
Abstract
Because magnetic resonance imaging-guided radiation therapy (MRIgRT) offers exquisite soft tissue contrast and the ability to image tissues in arbitrary planes, the interest in this technology has increased dramatically in recent years. However, intrinsic geometric distortion stemming from both the system hardware and the magnetic properties of the patient affects MR images and compromises the spatial integrity of MRI-based radiation treatment planning, given that for real-time MRIgRT, precision within 2 mm is desired. In this article, we discuss the causes of geometric distortion, describe some well-known distortion correction algorithms, and review geometric distortion measurements from 12 studies, while taking into account relevant imaging parameters. Eleven of the studies reported phantom measurements quantifying system-dependent geometric distortion, while 2 studies reported simulation data quantifying magnetic susceptibility-induced geometric distortion. Of the 11 studies investigating system-dependent geometric distortion, 5 reported maximum measurements less than 2 mm. The simulation studies demonstrated that magnetic susceptibility-induced distortion is typically smaller than system-dependent distortion but still nonnegligible, with maximum distortion ranging from 2.1 to 2.6 mm at a field strength of 1.5 T. As expected, anatomic landmarks containing interfaces between air and soft tissue had the largest distortions. The evidence indicates that geometric distortion reduces the spatial integrity of MRI-based radiation treatment planning and likely diminishes the efficacy of MRIgRT. Better phantom measurement techniques and more effective distortion correction algorithms are needed to achieve the desired spatial precision.
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Affiliation(s)
- Joseph Weygand
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas; The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas.
| | - Clifton David Fuller
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas; Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Geoffrey S Ibbott
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas; The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas
| | - Abdallah S R Mohamed
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas; Department of Clinical Oncology and Nuclear Medicine, Alexandria University, Alexandria, Egypt
| | - Yao Ding
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Jinzhong Yang
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas; The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas
| | - Ken-Pin Hwang
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Jihong Wang
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas; The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas
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MRI technique for the preoperative evaluation of deep infiltrating endometriosis: current status and protocol recommendation. Clin Radiol 2016; 71:179-94. [DOI: 10.1016/j.crad.2015.09.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 08/20/2015] [Accepted: 09/16/2015] [Indexed: 12/31/2022]
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134
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Lim D, Han Lee Y, Kim S, Song HT, Suh JS. Clinical value of fat-suppressed 3D volume isotropic spin-echo (VISTA) sequence compared to 2D sequence in evaluating internal structures of the knee. Acta Radiol 2016; 57:66-73. [PMID: 25585850 DOI: 10.1177/0284185114567560] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 12/16/2014] [Indexed: 11/17/2022]
Abstract
BACKGROUND Although many three-dimensional (3D) magnetic resonance imaging (MRI) sequences have been used in the clinical field, there are no studies on fat-suppressed (FS) 3D sequences for the diagnosis of knee abnormalities. PURPOSE To evaluate the usefulness of FS 3D volume isotropic turbo spin echo acquisition (VISTA) imaging for diagnosis of internal structures of knee. MATERIAL AND METHODS In 137 patients with 138 knee MRI examinations who had undergone both FS 3D VISTA MRI and two-dimensional (2D) MRI of the knee at 3.0 T, arthroscopic surgery was subsequently performed. Multiplanar reformations (MPR) of FS 3D VISTA images and their MPR sequences were compared with 2D MR images of axial T1-weighted (T1W) images, axial FS T2-weighted (T2W) images, coronal FS T2W images, and sagittal T2W images. Two musculoskeletal radiologists reviewed the images independently. RESULTS Arthroscopy revealed 33 anterior cruciate ligament tears, three posterior cruciate ligament tears, 42 lateral meniscus tears, and 68 medial meniscus tears. Five medial collateral ligament tears were clinically confirmed. Image acquisition time was shorter for FS 3D VISTA imaging than 2D imaging. There were no significant differences in diagnostic values between FS 3D VISTA and 2D imaging (P > 0.05). There were excellent inter-observer agreements for both FS 3D VISTA and 2D imaging (κ > 0.84). CONCLUSION FS 3D VISTA imaging could replace 2D imaging because of equal diagnostic ability and shorter scan time.
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Affiliation(s)
- Daekeon Lim
- Department of Radiology, Research Institute of Radiological Science, Medical Convergence Research Institute, and Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea
- Department of Radiology, Catholic Kwandong University International St. Mary’s Hospital, Incheon, Republic of Korea
| | - Young Han Lee
- Department of Radiology, Research Institute of Radiological Science, Medical Convergence Research Institute, and Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Sungjun Kim
- Department of Radiology, Research Institute of Radiological Science, Medical Convergence Research Institute, and Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Ho-Taek Song
- Department of Radiology, Research Institute of Radiological Science, Medical Convergence Research Institute, and Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Jin-Suck Suh
- Department of Radiology, Research Institute of Radiological Science, Medical Convergence Research Institute, and Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea
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136
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Sions JM, Smith AC, Hicks GE, Elliott JM. Trunk Muscle Size and Composition Assessment in Older Adults with Chronic Low Back Pain: An Intra-Examiner and Inter-Examiner Reliability Study. PAIN MEDICINE 2015; 17:1436-46. [PMID: 26814258 DOI: 10.1093/pm/pnv023] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Accepted: 09/05/2015] [Indexed: 11/13/2022]
Abstract
OBJECTIVE To evaluate intra- and inter-examiner reliability for the assessment of relative cross-sectional area, muscle-to-fat infiltration indices, and relative muscle cross-sectional area, i.e., total cross-sectional area minus intramuscular fat, from T1-weighted magnetic resonance images obtained in older adults with chronic low back pain. DESIGN Reliability study. SUBJECTS n = 13 (69.3 ± 8.2 years old) METHODS After lumbar magnetic resonance imaging, two examiners produced relative cross-sectional area measurements of multifidi, erector spinae, psoas, and quadratus lumborum by tracing regions of interest just inside fascial borders. Pixel-intensity summaries were used to determine muscle-to-fat infiltration indices; relative muscle cross-sectional area was calculated. Intraclass correlation coefficients were used to estimate intra- and inter-examiner reliability; standard error of measurement was calculated. RESULTS Intra-examiner intraclass correlation coefficient point estimates for relative cross-sectional area, muscle-to-fat infiltration indices, and relative muscle cross-sectional area were excellent for multifidi and erector spinae across levels L2-L5 (ICC = 0.77-0.99). At L3, intra-examiner reliability was excellent for relative cross-sectional area, muscle-to-fat infiltration indices, and relative muscle cross-sectional area for both psoas and quadratus lumborum (ICC = 0.81-0.99). Inter-examiner intraclass correlation coefficients ranged from poor to excellent for relative cross-sectional area, muscle-to-fat infiltration indices, and relative muscle cross-sectional area. CONCLUSIONS Assessment of relative cross-sectional area, muscle-to-fat infiltration indices, and relative muscle cross-sectional area in older adults with chronic low back pain can be reliably determined by one examiner from T1-weighted images. Such assessments provide valuable information, as muscle-to-fat infiltration indices and relative muscle cross-sectional area indicate that a substantial amount of relative cross-sectional area may be magnetic resonance-visible intramuscular fat in older adults with chronic low back pain.
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Affiliation(s)
- Jaclyn Megan Sions
- *Department of Physical Therapy, University of Delaware, Newark, Delaware, USA;
| | - Andrew Craig Smith
- Department of Physical Therapy and Human Movement Sciences, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Gregory Evan Hicks
- *Department of Physical Therapy, University of Delaware, Newark, Delaware, USA
| | - James Matthew Elliott
- Department of Physical Therapy and Human Movement Sciences, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
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137
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Lavdas E, Vlychou M, Zaloni E, Vassiou K, Tsagkalis A, Dailiana Z, Fezoulidis I. Elimination of motion and pulsation artifacts using BLADE sequences in shoulder MR imaging. Skeletal Radiol 2015; 44:1619-26. [PMID: 26306388 DOI: 10.1007/s00256-015-2232-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2015] [Revised: 07/02/2015] [Accepted: 08/02/2015] [Indexed: 02/02/2023]
Abstract
OBJECTIVES To evaluate the ability of proton-density with fat-suppression BLADE (proprietary name for periodically rotated overlapping parallel lines with enhanced reconstruction in MR systems from Siemens Healthcare, PDFS BLADE) and turbo inversion recovery magnitude-BLADE (TIRM BLADE) sequences to reduce motion and pulsation artifacts in shoulder magnetic resonance examinations. MATERIALS AND METHODS Forty-one consecutive patients who had been routinely scanned for shoulder examination participated in the study. The following pairs of sequences with and without BLADE were compared: (a) Oblique coronal proton-density sequence with fat saturation of 25 patients and (b) oblique sagittal T2 TIRM-weighed sequence of 20 patients. Qualitative analysis was performed by two experienced radiologists. Image motion and pulsation artifacts were also evaluated. RESULTS In oblique coronal PDFS BLADE sequences, motion artifacts have been significantly eliminated, even in five cases of non-diagnostic value with conventional imaging. Similarly, in oblique sagittal T2 TIRM BLADE sequences, image quality has been improved, even in six cases of non-diagnostic value with conventional imaging. Furthermore, flow artifacts have been improved in more than 80% of all the cases. CONCLUSIONS The use of BLADE sequences is recommended in shoulder imaging, especially in uncooperative patients because it effectively eliminates motion and pulsation artifacts.
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Affiliation(s)
- E Lavdas
- Department of Medical Radiological Technologists, Technological Education Institute of Athens, Greece, Athens, Greece
| | - M Vlychou
- Department of Radiology, Faculty of Medicine, University of Thessaly, Larissa, Greece.
| | - E Zaloni
- Department of Medical Radiological Technologists, Technological Education Institute of Athens, Greece, Athens, Greece
| | - K Vassiou
- Department of Radiology, Faculty of Medicine, University of Thessaly, Larissa, Greece
| | - A Tsagkalis
- Department of Orthopedics, IASO Hospital, Larissa, Greece
| | - Z Dailiana
- Department of Orthopedics, Faculty of Medicine, University of Thessaly, Larissa, Greece
| | - I Fezoulidis
- Department of Radiology, Faculty of Medicine, University of Thessaly, Larissa, Greece
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138
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Pagé M, Quarto C, Mancuso E, Mohiaddin RH. Metabolically Active Brown Fat Mimicking Pericardial Metastasis on PET/CT: The Discriminating Role of Cardiac Magnetic Resonance Imaging. Can J Cardiol 2015; 32:1039.e15-7. [PMID: 26860773 DOI: 10.1016/j.cjca.2015.10.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 10/06/2015] [Accepted: 10/12/2015] [Indexed: 10/22/2022] Open
Abstract
Metabolically active mediastinal brown adipose tissue may be mistakenly diagnosed as a malignancy on 18F-fluoro-2-deoxy-D-glucose (FDG)/positron emission tomography (PET). We report the case of a patient with locally recurrent breast carcinoma in which staging PET/CT revealed a suspicious pericardial lesion for which the patient was referred to our centre. The novelty of this case resides in the fact that by tissue characterization, cardiac magnetic resonance imaging allowed the determination that the lesion corresponded to brown fat, a reassuring finding with important impact on management, because the presence of pericardial metastasis would have disqualified this patient for curative resection of her cancer recurrence.
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Affiliation(s)
- Maude Pagé
- Cardiovascular Magnetic Resonance Unit, Royal Brompton Hospital, London, United Kingdom; Department of Cardiology, Hôpital du Sacré-Coeur de Montréal, Montréal, Québec, Canada
| | - Cesare Quarto
- Department of Cardiac Surgery, Royal Brompton Hospital, London, United Kingdom
| | - Enrico Mancuso
- Department of Cardiac Surgery, Royal Brompton Hospital, London, United Kingdom
| | - Raad H Mohiaddin
- Cardiovascular Magnetic Resonance Unit, Royal Brompton Hospital, London, United Kingdom; National Heart and Lung Institute, Imperial College London, United Kingdom.
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139
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Prakash JS, Rajamanickam K. Aptamers and Their Significant Role in Cancer Therapy and Diagnosis. Biomedicines 2015; 3:248-269. [PMID: 28536411 PMCID: PMC5344239 DOI: 10.3390/biomedicines3030248] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 08/07/2015] [Indexed: 02/07/2023] Open
Abstract
Aptamers are nucleic acid/peptide molecules that can be generated by a sophisticated, well-established technique known as Systematic Evolution of Ligands by EXponential enrichment (SELEX). Aptamers can interact with their targets through structural recognition, as in antibodies, though with higher specificity. With this added advantage, they can be made useful for clinical applications such as targeted therapy and diagnosis. In this review, we have discussed the steps involved in SELEX process and modifications executed to attain high affinity nucleic acid aptamers. Moreover, our review also highlights the therapeutic applications of aptamer functionalized nanoparticles and nucleic acids as chemo-therapeutic agents. In addition, we have described the development of "aptasensor" in clinical diagnostic application for detecting cancer cells and the use of aptamers in different routine imaging techniques, such as Positron Emission Tomography/Computed Tomography, Ultrasound, and Magnetic Resonance Imaging.
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Affiliation(s)
- Joy Sebastian Prakash
- Faculty of Allied Health Sciences (FAHS), Chettinad Academy of Research and Education, Kelambakkam, Chennai 603103, Tamil Nadu, India.
| | - Karunanithi Rajamanickam
- Faculty of Allied Health Sciences (FAHS), Chettinad Academy of Research and Education, Kelambakkam, Chennai 603103, Tamil Nadu, India.
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140
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Extremity-dedicated low-field MRI shows good diagnostic accuracy and interobserver agreement for the diagnosis of the acutely injured knee. Clin Imaging 2015; 39:871-5. [DOI: 10.1016/j.clinimag.2015.05.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 04/28/2015] [Accepted: 05/13/2015] [Indexed: 11/24/2022]
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141
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Olivieri LJ, Cross RR, O'Brien KE, Ratnayaka K, Hansen MS. Optimized protocols for cardiac magnetic resonance imaging in patients with thoracic metallic implants. Pediatr Radiol 2015; 45:1455-64. [PMID: 26040508 PMCID: PMC7610221 DOI: 10.1007/s00247-015-3366-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 03/31/2015] [Accepted: 04/15/2015] [Indexed: 11/29/2022]
Abstract
BACKGROUND Cardiac magnetic resonance (MR) imaging is a valuable tool in congenital heart disease; however patients frequently have metal devices in the chest from the treatment of their disease that complicate imaging. Methods are needed to improve imaging around metal implants near the heart. Basic sequence parameter manipulations have the potential to minimize artifact while limiting effects on image resolution and quality. OBJECTIVE Our objective was to design cine and static cardiac imaging sequences to minimize metal artifact while maintaining image quality. MATERIALS AND METHODS Using systematic variation of standard imaging parameters on a fluid-filled phantom containing commonly used metal cardiac devices, we developed optimized sequences for steady-state free precession (SSFP), gradient recalled echo (GRE) cine imaging, and turbo spin-echo (TSE) black-blood imaging. We imaged 17 consecutive patients undergoing routine cardiac MR with 25 metal implants of various origins using both standard and optimized imaging protocols for a given slice position. We rated images for quality and metal artifact size by measuring metal artifact in two orthogonal planes within the image. RESULTS All metal artifacts were reduced with optimized imaging. The average metal artifact reduction for the optimized SSFP cine was 1.5+/-1.8 mm, and for the optimized GRE cine the reduction was 4.6+/-4.5 mm (P < 0.05). Quality ratings favored the optimized GRE cine. Similarly, the average metal artifact reduction for the optimized TSE images was 1.6+/-1.7 mm (P < 0.05), and quality ratings favored the optimized TSE imaging. CONCLUSION Imaging sequences tailored to minimize metal artifact are easily created by modifying basic sequence parameters, and images are superior to standard imaging sequences in both quality and artifact size. Specifically, for optimized cine imaging a GRE sequence should be used with settings that favor short echo time, i.e. flow compensation off, weak asymmetrical echo and a relatively high receiver bandwidth. For static black-blood imaging, a TSE sequence should be used with fat saturation turned off and high receiver bandwidth.
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Affiliation(s)
- Laura J Olivieri
- Division of Cardiology, Children's National Health System, W3-200, 111 Michigan Ave. NW, Washington, DC, 20010, USA,
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142
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Mikhail AS, Partanen A, Yarmolenko P, Venkatesan AM, Wood BJ. Magnetic Resonance-Guided Drug Delivery. Magn Reson Imaging Clin N Am 2015; 23:643-55. [PMID: 26499281 DOI: 10.1016/j.mric.2015.05.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The use of clinical imaging modalities for the guidance of targeted drug delivery systems, known as image-guided drug delivery (IGDD), has emerged as a promising strategy for enhancing antitumor efficacy. MR imaging is particularly well suited for IGDD applications because of its ability to acquire images and quantitative measurements with high spatiotemporal resolution. The goal of IGDD strategies is to improve treatment outcomes by facilitating planning, real-time guidance, and personalization of pharmacologic interventions. This article reviews basic principles of targeted drug delivery and highlights the current status, emerging applications, and future paradigms of MR-guided drug delivery.
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Affiliation(s)
- Andrew S Mikhail
- Center for Interventional Oncology, Department of Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, 10 Center Drive, Bethesda, MD 20892, USA
| | - Ari Partanen
- Center for Interventional Oncology, Department of Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, 10 Center Drive, Bethesda, MD 20892, USA; Philips Healthcare, 3000 Minuteman Road, Andover, MA 01810, USA
| | - Pavel Yarmolenko
- The Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Medical Center, 111 Michigan Avenue, Washington, DC 20010, USA
| | - Aradhana M Venkatesan
- Section of Abdominal Imaging, Department of Diagnostic Radiology, M.D. Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030-4009, USA
| | - Bradford J Wood
- Center for Interventional Oncology, Department of Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, 10 Center Drive, Bethesda, MD 20892, USA.
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143
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Takayama Y, Nishie A, Asayama Y, Ishigami K, Kakihara D, Ushijima Y, Fujita N, Yoshiura T, Takemura A, Obara M, Takahara T, Honda H. Optimization and Clinical Feasibility of Free-breathing Diffusion-weighted Imaging of the Liver: Comparison with Respiratory-Triggered Diffusion-weighted Imaging. Magn Reson Med Sci 2015; 14:123-32. [PMID: 25740235 DOI: 10.2463/mrms.2014-0032] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
PURPOSE We compared the image quality of free-breathing diffusion-weighted imaging (FB-DWI) to that of respiratory-triggered DWI (RT-DWI) after proper optimization. MATERIALS AND METHODS Three healthy subjects were scanned to optimize magnetic resonance (MR) parameters of FB-DWI to improve image quality, including spatial resolution, image noise, and chemical shift artifacts. After this optimization, we scanned 32 patients with liver disease to assess the clinical feasibility of the optimized FB-DWI. Of the 32 patients, 14 had a total of 28 hepatocellular carcinomas (HCCs), four had a total of 15 metastatic liver tumors, and the other 14 had no tumor. Qualitatively, we compared the image quality scores of FB-DWI with those of RT-DWI with the Wilcoxon signed-rank test. Quantitatively, we compared the signal-to-noise ratios (SNRs) of the liver parenchyma, lesion-to-nonlesion contrast-to-noise ratios (CNRs) and apparent diffusion coefficient (ADC) values of the liver parenchyma and liver tumor by the paired t-test. RESULTS The average scores of image quality for sharpness of liver contour, image noise, and chemical shift artifacts were significantly higher for FB-DWI than RT-DWI (P < 0.05). SNRs, CNRs, and ADC values of the liver parenchyma and tumors did not differ significantly between the 2 DWI methods. CONCLUSION Compared with RT-DWI, the optimized FB-DWI provided better spatial resolution, fewer artifacts, and comparable SNRs, lesion-to-nonlesion CNRs, and ADC values.
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Affiliation(s)
- Yukihisa Takayama
- Department of Radiology Informatics and Network, Graduate School of Medical Sciences, Kyushu University
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144
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Del Grande F, Santini F, Herzka DA, Aro MR, Dean CW, Gold GE, Carrino JA. Fat-suppression techniques for 3-T MR imaging of the musculoskeletal system. Radiographics 2015; 34:217-33. [PMID: 24428292 DOI: 10.1148/rg.341135130] [Citation(s) in RCA: 223] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Fat suppression is an important technique in musculoskeletal imaging to improve the visibility of bone-marrow lesions; evaluate fat in soft-tissue masses; optimize the contrast-to-noise ratio in magnetic resonance (MR) arthrography; better define lesions after administration of contrast material; and avoid chemical shift artifacts, primarily at 3-T MR imaging. High-field-strength (eg, 3-T) MR imaging has specific technical characteristics compared with lower-field-strength MR imaging that influence the use and outcome of various fat-suppression techniques. The most commonly used fat-suppression techniques for musculoskeletal 3-T MR imaging include chemical shift (spectral) selective (CHESS) fat saturation, inversion recovery pulse sequences (eg, short inversion time inversion recovery [STIR]), hybrid pulse sequences with spectral and inversion-recovery (eg, spectral adiabatic inversion recovery and spectral attenuated inversion recovery [SPAIR]), spatial-spectral pulse sequences (ie, water excitation), and the Dixon techniques. Understanding the different fat-suppression options allows radiologists to adopt the most appropriate technique for their clinical practice.
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Affiliation(s)
- Filippo Del Grande
- From the Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Hospital, Baltimore, Md (F.D.G., M.R.A., J.A.C.); Division of Radiological Physics, Department of Radiology, Clinic of Radiology and Nuclear Medicine, University of Basel Hospital, Basel, Switzerland (F.S.); Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, Md (D.A.H.); Department of Radiology, University of Florida College of Medicine, Gainesville, Fla (C.W.D.); and Departments of Radiology, Bioengineering, and Orthopaedic Surgery, Stanford University School of Medicine, Stanford, Calif (G.E.G.). Recipient of a Certificate of Merit award for an education exhibit at the 2012 RSNA Annual Meeting
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145
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Nogueira L, Brandão S, Nunes RG, Ferreira HA, Loureiro J, Ramos I. Breast DWI at 3 T: influence of the fat-suppression technique on image quality and diagnostic performance. Clin Radiol 2014; 70:286-94. [PMID: 25555315 DOI: 10.1016/j.crad.2014.11.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Revised: 11/12/2014] [Accepted: 11/19/2014] [Indexed: 10/24/2022]
Abstract
AIM To evaluate two fat-suppression techniques: short tau inversion recovery (STIR) and spectral adiabatic inversion recovery (SPAIR) regarding image quality and diagnostic performance in diffusion-weighted imaging (DWI) of breast lesions at 3 T. MATERIALS AND METHODS Ninety-two women (mean age 48 ± 12.1 years; range 21-78 years) underwent breast MRI. Two DWI pulse sequences, with b-values (50 and 1000 s/mm(2)) were performed with STIR and SPAIR. The signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), suppression homogeneity, and apparent diffusion coefficient (ADC) values were quantitatively assessed for each technique. Values were compared between techniques and lesion type. Receiver operating characteristics (ROC) analysis was used to evaluate lesion discrimination. RESULTS One hundred and fourteen lesions were analysed (40 benign and 74 malignant). SNR and CNR were significantly higher for DWI-SPAIR; fat-suppression uniformity was better for DWI-STIR (p < 1 × 10(-4)). ADC values for benign and malignant lesions and normal tissue were 1.92 × 10(-3), 1.18 × 10(-3), 1.86 × 10(-3) s/mm(2) for DWI-STIR and 1.80 × 10(-3), 1.11 × 10(-3), 1.79 × 10(-3) s/mm(2) for SPAIR, respectively. Comparison between fat-suppression techniques showed significant differences in mean ADC values for benign (p = 0.013) and malignant lesions (p = 0.001). DWI-STIR and -SPAIR ADC cut-offs were 1.42 × 10(-3) and 1.46 × 10(-3) s/mm(2), respectively. Diagnostic performance for DWI-STIR versus SPAIR was: accuracy (81.6 versus 83.3%), area under curve (87.7 versus 89.2%), sensitivity (79.7 versus 85.1%), and specificity (85 versus 80%). Positive predictive value was similar. CONCLUSION The fat-saturation technique used in the present study may influence image quality and ADC quantification. Nevertheless, STIR and SPAIR techniques showed similar diagnostic performances, and therefore, both are suitable for use in clinical practice.
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Affiliation(s)
- Luisa Nogueira
- Department of Radiology, School of Health Technology of Porto/Polytechnic Institute of Porto (ESTSP/IPP), Rua Valente Perfeito, 4400-330, Vila Nova de Gaia, Portugal; Department of Radiology, Hospital de São João/Faculty of Medicine of Porto University (FMUP), Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal.
| | - Sofia Brandão
- MRI Unit, Department of Radiology, Hospital de São João, Alameda Prof. Hernani Monteiro, 4200-319 Porto, Portugal
| | - Rita G Nunes
- Institute of Biophysics and Biomedical Engineering (IBEB), Faculty of Sciences, University of Lisbon, Campo Grande, 1749-016, Lisboa, Portugal
| | - Hugo Alexandre Ferreira
- Institute of Biophysics and Biomedical Engineering (IBEB), Faculty of Sciences, University of Lisbon, Campo Grande, 1749-016, Lisboa, Portugal
| | - Joana Loureiro
- MRI Unit, Department of Radiology, Hospital de São João, Alameda Prof. Hernani Monteiro, 4200-319 Porto, Portugal
| | - Isabel Ramos
- Department of Radiology, Hospital de São João/Faculty of Medicine of Porto University (FMUP), Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal
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146
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Young BD, Mankin JM, Griffin JF, Fosgate GT, Fowler JL, Levine JM. Comparison of two fat-suppressed magnetic resonance imaging pulse sequences to standard t2-weighted images for brain parenchymal contrast and lesion detection in dogs with inflammatory intracranial disease. Vet Radiol Ultrasound 2014; 56:204-11. [PMID: 25395066 DOI: 10.1111/vru.12220] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2014] [Accepted: 08/20/2014] [Indexed: 11/28/2022] Open
Abstract
T2-weighted (T2w) sequences are commonly relied upon in magnetic resonance imaging protocols for the detection of brain lesions in dogs. Previously, the effect of fluid suppression via fluid-attenuated inversion recovery (FLAIR) has been compared to T2-weighting with mixed results. Short tau inversion recovery (STIR) has been reported to increase the detection of some CNS lesions in people. The purpose of the current study was to evaluate the effect of fat suppression on brain parenchymal contrast resolution and lesion detection in dogs. We compared three sequences: T2w images, STIR, and T2w FLAIR with chemical fat suppression (T2-FLAIR-FS) in dogs with meningoencephalitis. Dogs with meningoencephalitis and dogs with idiopathic epilepsy were retrospectively identified and anonymized. Evaluators recorded the presence or absence of lesions within 12 predetermined brain regions on randomized sequences, viewing and scoring each sequence individually. Additionally, signal-to-noise ratios, contrast-to-noise ratios, and relative contrast (RC) were measured in a reference population. Short tau inversion recovery sequences had the highest RC between gray and white matter. While descriptively more lesions were identified by evaluators on T2-FLAIR-FS images, there was no statistical difference in the relative sensitivity of lesion detection between the sequences. Nor was there a statistical difference in false lesion detection within our reference population. Short tau inversion recovery may be favored for enhanced anatomic contrast depiction in brain imaging. No benefit of the inclusion of a fat-suppressed T2-FLAIR sequence was found.
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Affiliation(s)
- Benjamin D Young
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843
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147
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Chemical shift and fat suppression magnetic resonance imaging of thymus in myasthenia gravis. Can J Neurol Sci 2014; 41:782-6. [PMID: 25385429 DOI: 10.1017/cjn.2014.104] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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148
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Schieda N, Al Dandan O, Kielar A, Flood T, McInnes M, Siegelman E. Pitfalls of adrenal imaging with chemical shift MRI. Clin Radiol 2014; 69:1186-97. [DOI: 10.1016/j.crad.2014.06.020] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 06/17/2014] [Accepted: 06/24/2014] [Indexed: 10/25/2022]
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149
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Woo S, Cho JY, Kim SY, Kim SH. Adrenal adenoma and metastasis from clear cell renal cell carcinoma: can they be differentiated using standard MR techniques? Acta Radiol 2014; 55:1120-8. [PMID: 24252816 DOI: 10.1177/0284185113512301] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
BACKGROUND Chemical-shift magnetic resonance imaging (MRI) has been known to successfully differentiate adenomas from metastases. However, there has been concern that metastasis from extra-adrenal primary malignancies which contain high lipid content such as clear cell renal cell carcinoma (RCC) could mimic adrenal adenomas. PURPOSE To evaluate the ability of MR to differentiate adrenal adenoma from metastasis using chemical-shift imaging and MR feature analysis in patients with clear cell RCC. MATERIAL AND METHODS This study was institutional review board-approved; informed consent was waived. Eleven patients with 13 metastases and 13 patients with 15 adrenal adenomas in patients with clear cell RCC for evaluation of an adrenal mass underwent MR. Signal intensity on in- and opposed-phases, signal intensity index (SII), size, T2 SI, cystic change, necrosis, and hemorrhage were evaluated. Statistical analyses included Student t-test and Fisher exact test. If available, precontrast CT attenuation of the adrenal adenomas was measured. SII was correlated with attenuation using Pearson correlation coefficient. RESULTS Mean size of adenomas was smaller than that of metastases (P < 0.002). Mean SII of adenomas (45.0% ± 24.6) was significantly greater than that of metastases (6.6% ± 4.7; P < 0.001). With a threshold of 16.5% for SII, the sensitivity, specificity, and accuracy for adenomas were 80%, 100%, and 89.2%, respectively. All six lipid-rich adenomas were diagnosed as adrenal adenoma. Three of eight (37.5%) lipid-poor adenomas were misdiagnosed as metastases. While up to 53.8% (7/13) of the metastases demonstrated cystic change, necrosis, or hemorrhage, only one (6.7%) adenoma exhibited cystic change or necrosis (P < 0.05 for all). Precontrast attenuation and SII were significantly correlated: r = -0.810 (P < 0.001). CONCLUSION In patients with clear cell RCC who underwent MR for adrenal masses, SII and MR features such as cystic change, necrosis, and hemorrhage were helpful in differentiating adenomas from metastases.
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Affiliation(s)
- Sungmin Woo
- Department of Radiology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Jeong Yeon Cho
- Department of Radiology, Seoul National University College of Medicine, Seoul, Republic of Korea
- Institute of Radiation Medicine and Kidney Research Institute, Seoul National University Medical Research Center, Seoul, Republic of Korea
| | - Sang Youn Kim
- Department of Radiology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Seung Hyup Kim
- Department of Radiology, Seoul National University College of Medicine, Seoul, Republic of Korea
- Institute of Radiation Medicine and Kidney Research Institute, Seoul National University Medical Research Center, Seoul, Republic of Korea
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150
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Amini B, Jessop AC, Ganeshan DM, Tseng WW, Madewell JE. Contemporary imaging of soft tissue sarcomas. J Surg Oncol 2014; 111:496-503. [DOI: 10.1002/jso.23801] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 08/14/2014] [Indexed: 12/15/2022]
Affiliation(s)
- Behrang Amini
- Department of Diagnostic Radiology; The University of Texas M.D. Anderson Cancer Center; Houston Texas
| | - Aaron C. Jessop
- Department of Diagnostic Radiology; The University of Texas M.D. Anderson Cancer Center; Houston Texas
| | - Dhakshina M. Ganeshan
- Department of Diagnostic Radiology; The University of Texas M.D. Anderson Cancer Center; Houston Texas
| | - William W. Tseng
- Division of Upper GI/General Surgery; Section of Surgical Oncology; University of Southern California; Los Angeles California
- Hoag Family Cancer Institute, Hoag Memorial Hospital Presbyterian, Newport Beach; California
| | - John E. Madewell
- Department of Diagnostic Radiology; The University of Texas M.D. Anderson Cancer Center; Houston Texas
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