In Vivo 7.0-Tesla Magnetic Resonance Imaging of the Wrist and Hand: Technical Aspects and Applications

Friedrich, Klaus; Chang, Gregory; Vieira, Renata; Wang, Ligong; Wiggins, Graham C.; Schweitzer, Mark E.; Regatte, Ravinder R.

doi:10.1055/s-0029-1202942

Cited by 34 publications

(30 citation statements)

References 39 publications

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“…Our results show better visibility of articular cartilage surfaces, higher diagnostic accuracy, and higher levels of confidence for 3.0T than for 7.0T. Although there have been initial reports about 7.0T wrist MRI (14,25,28), this is, to our best knowledge, the first study on MR arthrography and the first study which uses a reliable reference standard (pathologic dissection). We used standard spin-echo-based MR sequences with identical acquisition parameters on both field strengths.…”

Section: Discussionmentioning

confidence: 56%

“…In the study of Ashman et al (29) a customdesigned wrist coil with a 12 cm diameter was used at 8.0T. Regatte's group (14,25) reported the use of an eight-receive four-transmit coil at 7.0T which was initially developed for dedicated MRI of carotid arteries. The latter coil allowed parallel imaging as well as a low RF power deposition due to its transmit capability.…”

Section: Discussionmentioning

confidence: 99%

“…Both coils had an identical design and allowed accommodation to different wrist sizes. Specific absorption rate (SAR) limits are usually not a problem in wrist MRI, as it is thought that local transmit coils reduce the amount of RF required for imaging of small joints to negligible levels that are within the regulatory limitations for specific absorption rates (25). Recently, the first commercial extremity coils for 7.0T have become available; however, to the best of our knowledge, there is still no dedicated wrist coil available.…”

Section: Discussionmentioning

confidence: 99%

“…The overall acquisition time was similar for both field strengths. Since this is the first MR arthrography comparison between 3.0T and 7.0T and due to the limited knowledge of 7.0T tissue and contrast media relaxation parameters, we decided to keep most acquisition parameters identical between 3.0T and 7.0T with the exception of the receiver bandwidth, which was adjusted for 7.0T-primarily to account for chemical shift artifacts (25).…”

Section: Mrimentioning

confidence: 99%

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Direct MR arthrography of cadaveric wrists: Comparison between MR imaging at 3.0T and 7.0T and gross pathologic inspection

Donati

Nordmeyer-Massner

Nanz

et al. 2011

Magnetic Resonance Imaging

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Purpose: To prospectively evaluate the diagnostic accuracy of magnetic resonance (MR) arthrography for the detection of articular cartilage abnormalities at 3.0T and 7.0T in cadaveric wrists.Materials and Methods: MR imaging (MRI) was performed in nine cadaveric wrists (four right wrists, five left; mean age, 81.0 6 9.8 years) after the intraarticular administration of gadoterate-meglumine. A 3.0T and 7.0T MR system, mechanically identical custom-built 8-channel wrist coil arrays and a similar standard MRI protocol, were used. MR images were evaluated for visibility of articular cartilage surfaces, presence of cartilage lesions, and confidence of diagnosis by two independent radiologists. Open pathologic inspection served as reference standard. Sensitivity, specificity, negative predictive values (NPV) and positive predictive values (PPV), and accuracy (ACC) were calculated. Wilcoxon signed rank test was used to assess differences in the diagnostic performance.Results: Visibility of articular cartilage surfaces was significantly better at 3.0T than at 7.0T (P < 0.001). Mean sensitivity, specificity, NPV, PPV, ACC for both readers were 63%, 90%, 85%, 76%, 82% at 3.0T, respectively, and 52%, 91%, 82%, 75%, 79% at 7.0T. The difference between 3.0T and 7.0T was not significant for reader 1 (P ¼ 0.51), but was significant for reader 2 (P ¼ 0.01). The level of confidence was significantly higher at 3.0T than at 7.0T for both readers (P ¼ 0.004; P ¼ 0.03).Conclusion: MR arthrography of the wrist at 7.0T is still limited by the lack of commercially available radiofrequency coils and limited experience in sequence optimization, resulting in a significantly lower visibility of anatomy, lower diagnostic accuracy, and level of confidence in judging cartilage lesions compared to 3.0T. MAGNETIC RESONANCE IMAGING (MRI) is an important noninvasive diagnostic imaging tool for the evaluation of wrist lesions. It has been shown to be particularly helpful for the detection of tears of the triangular fibrocartilage complex (TFCC), the scapholunate (SL), and lunotriquetral (LT) ligament, as well as for the evaluation of tendon abnormalities around the wrist (1-5). With regard to the evaluation of articular cartilage lesions, however, the literature is sparse.High-field MRI at a field strength of 3.0T has shown promising results in musculoskeletal radiology (6)(7)(8)(9)(10)(11)(12) and is increasingly used in clinical practice (13). Imaging at 3.0T offers an %2-fold increase in signalto-noise ratio (SNR) when compared to 1.5T MRI systems. The increase in SNR may directly improve the diagnostic accuracy due to better lesion conspicuity or it can be translated into an increase in spatial resolution or imaging speed (14). Thus, a potential clinical advantage of 3.0T over 1.5T MRI includes improved imaging of small or thin structures such as the articular cartilage of the radiocarpal and intercarpal joints, which is typically less than 1 mm thick (15-18).In the past 3 years, ultrahigh-field whole-body MRI scanners operating at a field str...

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Section: Discussionmentioning

confidence: 56%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Mrimentioning

confidence: 99%

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Direct MR arthrography of cadaveric wrists: Comparison between MR imaging at 3.0T and 7.0T and gross pathologic inspection

Donati

Nordmeyer-Massner

Nanz

et al. 2011

Magnetic Resonance Imaging

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“…The wrist with its smaller anatomical structures may benefit greatly from the improved diagnostic capabilities that 7.0-T MR has to offer, if the current technical challenges are overcome. 61 MR arthrography of the wrist at 7.0 T currently remains problematic because of the lack of dedicated radiofrequency coils and limited experience in sequence optimization; the result is poor assessment of anatomy, and lower diagnostic accuracy and level of confidence in judging cartilage lesions compared with 3.0 T. 62 …”

Section: Future Developmentsmentioning

confidence: 99%

Imaging of the wrist

Khanna¹,

Walker²

2014

Imaging

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MR or CT is advocated in the assessment of radiographically occult fractures. • The intrinsic ligaments of the wrist are better visualized at 3.0-T MRI than at 1.5-T MRI; however, MR or multidetector CT arthrography is the most sensitive at detecting intrinsic ligament and triangular fibrocartilage complex (TFCC) tears. • MR is more sensitive at detecting scapholunate ligament tears than lunotriquetral ligament tears. • TFCC tears can be divided into traumatic or degenerative tears, the latter being related to ulnar impaction syndrome. • Chronic wrist pain as a result of trauma may be secondary to scaphoid avascular necrosis, malunion, non-union, scapholunate advanced collapse and scaphoid nonunion advanced collapse wrist or chronic regional pain syndrome. • Specific ulnar-sided wrist pain has its own unique causes that are optimally imaged with MR. • Doppler ultrasound and dynamic-enhanced MRI are the most sensitive imaging tools for diagnosing and monitoring synovitis in inflammatory arthropathies. • Most masses in the wrist and hand are benign and have typical imaging appearances.Abstract. This article details the current imaging modalities utilized in the assessment of wrist pathology, with particular emphasis on recent developments and difficult areas. A stepwise approach for the assessment of wrist pathology in the context of clinical presentation will be discussed. The radiologist's role in the evaluation of wrist pain continues to evolve with the growing development of new techniques in order to evaluate with greater sensitivity the disorders affecting the complex joint and ligamentous structures of the wrist. The imaging strategy for wrist pathology begins with radiographs, with the use of further imaging such as ultrasound, CT, MRI and arthrography techniques if the diagnosis remains unclear.Acutely painful wrist following trauma

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Encapsulated gadolinium and dysprosium ions within ultra‐short carbon nanotubes for MR microscopy at 11.75 and 21.1 T

Rosenberg

Cisneros

Matson

et al. 2014

Contrast Media & Molecular

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Single-walled carbon nanotubes (SWNTs) have gained interest for their biocompatibility and multifunctional properties. Ultra-short SWNTs (US-tubes) have demonstrated high proton relaxivity when encapsulating gadolinium ions (Gd(3+)) at clinical field strengths. At higher field strengths, however, Gd(3+) ions demonstrate decreased proton relaxation properties while chemically similar dysprosium ions (Dy(3+)) improve relaxation properties. This report investigates the first use of Gd(3+) and Dy(3+) ions within US-tubes (GNTs and DNTs, respectively) at ultra-high magnetic field (21.1 T). Both agents are compared in solution and as an intracellular contrast agent labeling a murine microglia cell line (Bv2) immobilized in a tissue-mimicking agarose phantom using two high magnetic fields: 21.1 and 11.75 T. In solution at 21.1 T, results show excellent transverse relaxation; DNTs outperformed GNTs as a T(2) agent with measured r(2)/r(1) ratios of 247 and 47, respectively. Additionally, intracellular DNTs were shown to be a better T(2) agent than GNTs with higher contrast percentages and contrast-to-noise ratios. As such, this study demonstrates the potential of DNTs at high magnetic fields for cellular labeling and future in vivo, MRI-based cell tracking.

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In Vivo 7.0-Tesla Magnetic Resonance Imaging of the Wrist and Hand: Technical Aspects and Applications

Cited by 34 publications

References 39 publications

Direct MR arthrography of cadaveric wrists: Comparison between MR imaging at 3.0T and 7.0T and gross pathologic inspection

Direct MR arthrography of cadaveric wrists: Comparison between MR imaging at 3.0T and 7.0T and gross pathologic inspection

Imaging of the wrist

Encapsulated gadolinium and dysprosium ions within ultra‐short carbon nanotubes for MR microscopy at 11.75 and 21.1 T

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