Preliminary experimental results in humans and animals with a superconducting, whole-body, nuclear magnetic resonance scanner.

Alfidi, Ralph J.; Haaga, John R.; El-Yousef, S J; Bryan, Patrick J.; Fletcher, Barry D.; LiPuma, J. P.; Morrison, Stuart C.; Kaufman, Benjamin; Richey, Joseph; Hinshaw, W. S.; Kramer, David; Yeung, Hong N.; Cohen, Alan M.; Butler, Harold E.; Ament, Albert E.; Lieberman, James M.

doi:10.1148/radiology.143.1.7063723

Cited by 141 publications

(23 citation statements)

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“…Early investigators felt that differences in relaxation times between tumors and normal tissue made contrast agents unnecessary. However, despite this intrinsic tissue contrast, the absence of oral or intravenous contrast agents has proved disadvantageous (1,2). Various intravenous and oral contrast agents have been proposed, including paramagnetic metal ions and their chelates and complexes (3,4).…”

mentioning

confidence: 99%

Selective modification of NMR relaxation time in human colorectal carcinoma by using gadolinium-diethylenetriaminepentaacetic acid conjugated with monoclonal antibody 19-9.

Curtet¹,

Tellier²,

Bohy³

et al. 1986

Proc. Natl. Acad. Sci. U.S.A.

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Monoclonal antibody 19-9 (mAb 19-9) against human colon adenocarcinoma was conjugated with gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA) and used as a contrast agent in nuclear magnetic resonance (NMR) in an effort to improve tumor target selectivity in nude mice. The data indicate that Gd-DTPA-mAb 19-9 in solution decreased the T1 relaxation of water protons at 90 MHz in direct proportion to the gadolinium concentration, and this effect was greater than in Gd-DTPA solutions. T1 relaxation time at 90 MHz, measured in tumors removed from nude mice 24 hr after injection of GdDTPA-mAb 19-9 (Gd, 20 pumol/kg; 16 DTPA molecules per mAb molecule), was significantly decreased (by 15%) as compared with the control group. Similar results were obtained in tumors from mice injected with GdDTPA-mAb 19-9 solutions in which Gd was used at 2, 6, or 10 jsmol/kg (16 DTPA molecules per mAb molecule). These doses are lower than those commonly used for GdDTPA (10-100 j#mol/kg) as contrast agent. Tumor localiztion by the Gd-DTPA-mAb 19-9 complex containing radioactive Gd (0.3 IACi/tg of ls3Gd) to confirm scintigraphy revealed significant concentrations of the complex (5% of the injected dose per gram of tissue) in the tumor. Scan images recorded in planar scintigraphy at day 5 showed good visualization of tumors.Nuclear magnetic resonance (NMR) proton imaging provides sharp contrast between tissues based on their intrinsic T1 and T2 relaxation times when varied pulse sequences are used. By exploiting the differences in relaxation times, images have been produced that provide previously unobtainable anatomic and physiologic information. Early investigators felt that differences in relaxation times between tumors and normal tissue made contrast agents unnecessary. However, despite this intrinsic tissue contrast, the absence of oral or intravenous contrast agents has proved disadvantageous (1, 2). Various intravenous and oral contrast agents have been proposed, including paramagnetic metal ions and their chelates and complexes (3, 4). Recently, attention has focused on gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA), a complex that produces a marked reduction in the proton relaxation ratio in vitro and in vivo and appears to have minimal acute toxicity in imaging doses (5, 6). One approach to increasing the specificity of NMR image contrast is to use paramagnetic contrast agents coupled with a monoclonal

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mentioning

confidence: 99%

Selective modification of NMR relaxation time in human colorectal carcinoma by using gadolinium-diethylenetriaminepentaacetic acid conjugated with monoclonal antibody 19-9.

Curtet¹,

Tellier²,

Bohy³

et al. 1986

Proc. Natl. Acad. Sci. U.S.A.

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“…13 there are only a few reports on its application to experimental studies in animals. [4][5][6] A new imaging technique was safely developed for animal experiments. It is of interest to evaluate the characteristics of NMR imaging and its potential application to neuropathology, based on an experimental model such as brain edema induced by cryo-injury.…”

Section: Resultsmentioning

confidence: 99%

Acute NMR changes during MCA occlusion: a preliminary study in primates.

Spetzler¹,

Zabramski²,

Kaufman³

et al. 1983

Stroke

Self Cite

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SUMMARY Advancements in computer science and magnet design have resulted in the recent development of high resolution NMR imaging systems. Using our primate model we evaluated the ability of NMR scanning to detect early changes following middle cerebral artery (MCA) occlusion.Serial NMR scans documented progressive changes secondary to edema and swelling beginning ninety minutes after MCA occlusion. NMR was also able to readily demonstrate the area of cerebral infarct 10 days after a six hour episode of MCA occlusion.Soft tissue contrast and image resolution were superb. Correlation with pathologic sections was excellent.Stroke, Vol 14, No 2, 1983 THE PHENOMENON OF NUCLEAR MAGNETIC RESONANCE (NMR) was first reported for the hydrogen nuclei of water and paraffin in 1946. '• 2 Hydrogen nuclides (protons, deuterium, and tritium) and the isotopes of certain other elements ( 13 C, 31 P, etc.) share the common property of having an intrinsic nuclear magnetic dipole moment. As a result they can be thought of as behaving like small bar magnets. Normally in a sample containing the nuclides, these nuclear magnets are randomly orientated so that the net nuclear magnetism is zero ( fig. la). When such a sample is placed in a strong static magnetic field, however, the nuclear magnets tend to realign themselves with the direction of the lines of force in the magnetic field (fig. lb) so that the nuclear magnetic forces are additive ( fig. lb). Thermal motions within the sample tend to disturb this alignment. The net effect of these opposing forces is a macroscopic quantity called magnetization. At equilibrium the magnitude of this nuclear magnetization vector is directly proportional to the strength of the applied magnetic field, and inversely proportional to the absolute temperature (Curie's Law). One of the most common ways to obtain an NMR signal is to use a short, intense radio frequency (RF) pulse applied transverse to the direction of the static magnetic field. By choosing an appropriate frequency for the RF pulse the nuclei of interest (e.g. the hydrogen proton, 'H) can be forced to rotate (or precess) about the axis of the static magnetic field ( fig. 2). Following the RF pulse, then, the magnetization of these stimulated nuclei (the sum of the rotating nuclear magnetic vector moments) is no longer in alignment with the static field and undergoes free precession in the magnetic field at an

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“…Gated cardiac images in man which have been generated using a gated saturation re covery or spin echo pulse sequence tend to highlight proton density [2], Figure 5 clearly depicts cardiac anatomy throughout the car diac cycle; the anticipated changes in cardiac chamber size can be seen. In addition, the aortic outflow tract and thoracic arteries can be seen in figure 6.…”

Section: Proton Nmr Imaging Of the Heartmentioning

confidence: 99%