磁気共振における分子間相関性に基づく正確な温度イメージング
Gigi Galiana1, Rosa T Branca, Elizabeth R Jenista
1Department of Chemistry, Princeton University, Princeton, NJ 08544, USA.
Science (New York, N.Y.)
|October 18, 2008
まとめ
この研究は,さまざまな組織における正確な温度測定のための新しい磁気共鳴画像法を導入しています. この技術は,従来の方法の限界を克服し,イン・ビヴォの正確な温度マッピングを可能にします.
科学分野:
- バイオメディカルエンジニアリング
- メディカルイマージング (医学イメージング)
- 物理 物理学 物理学とは
背景:
- 従来の磁気共鳴 (MR) 温度測定法では,磁場不均一性と探査機の動力学により,精度に問題があります.
- 既存のテクニックは,脂肪組織などの特定の組織で不十分なパフォーマンスを発揮し,臨床的有用性を制限しています.
- 正確な内部温度モニタリングは,高温療法のようなアプリケーションにとって非常に重要です.
研究 の 目的:
- 頑丈で正確な in vivo 温度イメージングのための新しい MR 方法の開発と検証.
- 困難な環境での従来のMR温度計の限界に対処するために.
- 生物組織における絶対温度スケール測定のための信頼できるツールを提供すること.
主な方法:
- 温度依存の信号生成のために利用された分子間ゼロ-量子相関性 (iZQC).
- 水と脂肪のスピンを同時に操作する技術を採用した.
- 快速で正確な in vivo 温度割り当ての方法を検証しました.
主要な成果:
- 新しく開発されたMRメソッドは,さまざまな環境で温度を画像化するのに適していることを示しています.
- この技術は,不均質な磁場に関連する不正確さを克服します.
- 絶対的なスケールでの迅速かつ正確な in vivo 温度割り当てが成功しました.
結論:
- 開発されたiZQCベースのMR温度計は,従来の方法よりも著しく進歩しています.
- この技術は,難しい脂肪組織を含む様々な生物学的組織で,正確かつ信頼性の高い温度マッピングを提供します.
- この方法は,特に高温症の治療において,臨床応用の強化を約束しています.
関連する概念動画
01:24Magnetic Resonance Imaging
Magnetic resonance imaging (MRI) is a noninvasive medical imaging technique based on a phenomenon of nuclear physics discovered in the 1930s, in which matter exposed to magnetic fields and radio waves was found to emit radio signals. In 1970, a physician and researcher named Raymond Damadian noticed that malignant (cancerous) tissue gave off different signals than normal body tissue. He applied for a patent for the first MRI scanning device in clinical use by the early 1980s. The early MRI...
01:15¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR
The axial and equatorial protons in cyclohexane can be distinguished by performing a variable-temperature NMR experiment. In this process, except for one proton, the remaining eleven protons are replaced by deuterium. The deuterium substitution avoids the possible peak splitting caused by the spin-spin coupling between the adjacent protons. The remaining proton flips between the axial and equatorial positions.
01:14NMR Spectrometers: Resolution and Error Correction
When magnetic nuclei in a sample achieve resonance and undergo relaxation, the signal detected in NMR is an approximately exponential free induction decay. Fourier transform of an exponential decay yields a Lorentzian peak in the frequency domain. Lorentzian peaks in an NMR spectrum are defined by their amplitude, full width at half maximum, and position, where the peak width is governed by the spin-spin relaxation time alone. In real experiments, however, the applied magnetic field is rendered...
01:05Atomic Nuclei: Magnetic Resonance
The number of nuclear spins aligned in the lower energy state is slightly greater than those in the higher energy state. In the presence of an external magnetic field, as the spins precess at the Larmor frequency, the excess population results in a net magnetization oriented along the z axis. When a pulse or a short burst of radio waves at the Larmor frequency is applied along the x axis, the coupling of frequencies causes resonance and flips the nuclear spins of the excess population from the...
01:27Imaging Studies IV: Magnetic Resonance Imaging
Introduction:Magnetic Resonance Imaging, or MRI, can include a specialized imaging technique of the urinary system known as Magnetic Resonance Urography (MRU). This radiation-free technique uses strong magnetic fields and radio waves to produce detailed images with the help of a computer. MRU is particularly effective for visualizing fluid-filled structures like the kidneys, ureters, and bladder.Applications of MRI in the Genitourinary SystemKidneys and Ureters: MRI detects tumors, cysts,...
01:27Atomic Spectroscopy: Effects of Temperature
Atomization, converting samples into gas-phase atoms and ions, is essential for atomic spectroscopy. The flame temperature required for atomization affects the efficiency of the atomic spectroscopic methods by increasing the atomization efficiency and the relative population of the excited and ground states.
At thermal equilibrium, the relative populations of excited and ground state atoms can be estimated using the Maxwell–Boltzmann distribution. For example, an increase in temperature from...
At thermal equilibrium, the relative populations of excited and ground state atoms can be estimated using the Maxwell–Boltzmann distribution. For example, an increase in temperature from...