0000000000306862
AUTHOR
Michael V. Knopp
Nuclear magnetic resonance imaging of airways in humans with use of hyperpolarized3He
The nuclear spin polarization of noble gases can be enhanced strongly by laser optical pumping followed by electron-nuclear polarization transfer. Direct optical pumping of metastable 3He atoms has been shown to produce enormous polarization on the order of 0.4-0.6. This is about 105 times larger than the polarization of water protons at thermal equilibrium used in conventional MRI. We demonstrate that hyperpolarized 3 He gas can be applied to nuclear magnetic resonance imaging of organs with air-filled spaces in humans. In vivo 3 He MR experiments were performed in a whole-body MR scanner with a superconducting magnet ramped down to 0.8 T. Anatomical details of the upper respiratory tract …
Bone marrow after autologous blood stem cell transplantation and total body irradiation: magnetic resonance and chemical shift imaging.
Magnetic resonance studies of the lumbar, pelvic, and femoral bone marrow were performed in 10 patients after autologous blood stem cell transplantation, including total body irradiation and myeloablative chemotherapy. The posttreatment interval varied between 2 and 6 yr. The appearance on T1-weighted images and the quantitative data obtained from chemical shift imaging (relative fat signal) were compared to 10 age-matched healthy volunteers. The classification of the T1-weighted images yielded no significant differences between the two groups. Chemical shift imaging by determination of the relative fat signal was able to detect a significant fatty replacement of the patients' lumbar (p < .…
Angiogenesis of cancer of the cervix. Contrast-enhanced dynamic MRT, histological quantification of capillary density and lymph system infiltration
Purpose: It was the aim of this project to examine (i) the relationships between contrast-enhanced dynamic MR imaging derived characteristics and histologic microvessel density counts – a recognized surrogate of tumor angiogenesis – from tumors in patients with primary or recurrent cancer of the uterine cervix, and (ii) to correlate these parameters with lymphatic involvement (i. e. lymphatic channels) to assess tumorbiological aggressiveness in terms of lymphatic spread. Materials and methods: Pharmacokinetic MR imaging parameters (amplitude A, exchange rate constant k 21) were derived from contrast-enhanced dynamic MR imaging in thirty-three patients with biopsy proven cancer of the uteri…
Normal and abnormal pulmonary ventilation: visualization at hyperpolarized He-3 MR imaging.
To assess the feasibility of helium-3 magnetic resonance (MR) imaging with a three-dimensional fast low-angle shot (FLASH) sequence, He-3 gas (volume, 300 mL; pressure, 3 x 10(5) Pa; polarized up to 45% by means of optimal pumping) was inhaled by five healthy volunteers and five patients with pulmonary diseases. All breath-hold examinations (22-42 seconds) were completed successfully. Normal ventilation was depicted with homogeneous high signal intensity, lesions were depicted as causing defects, and obstructive lung disease was depicted with severely inhomogeneous signal intensity.
Nuclear magnetic resonance imaging with hyperpolarised helium-3
Abstract Summary Background Magnetic resonance imaging (MRI) relies on magnetisation of hydrogen nuclei (protons) of water molecules in tissue as source of the signal. This technique has been valuable for studying tissues that contain significant amounts of water, but biological settings with low proton content, notably the lungs, are difficult to image. We report use of spin-polarised helium-3 for lung MRI. Methods A volunteer inhaled hyperpolarised 3 He to fill the lungs, which were imaged with a conventional MRI detector assembly. The nuclear spin polarisation of helium, and other noble gases, can be greatly enhanced by laser optical pumping and is about 10 5 times larger than the polari…
Magnetically labeled water perfusion imaging of the uterine arteries and of normal and malignant cervical tissue: initial experiences.
Purpose: The aim of this pilot study was to evaluate a magnetically labeled water perfusion imaging technique as a non-contrast-enhanced approach to demonstrate the uterine artery, its branches, and to assess the cervical uterine blood flow in healthy volunteers and in patients with advanced uterine cervical carcinoma (FIGO IIB-IVA). Methods and Materials: Seven healthy volunteers (mean age, 29 years) and twenty-two patients (mean age, 52 years) with advanced cancer of the uterine cervix (FIGO IIB-IVA) were prospectively examined by magnetically labeled water perfusion imaging at different inversion delay times (300–900 ms). The magnetic resonance imaging (MRI) findings of all patients were…
Fatty replacement of bone marrow after radiation therapy for Hodgkin disease: Quantification with chemical shift imaging
The authors studied the long-term fatty replacement of bone marrow in 23 patients who had received radiation therapy for Hodgkin disease, with T1-weighted magnetic resonance imaging and quantitative chemical shift imaging. T1-weighted images revealed a mostly homogeneous high-signal-intensity pattern, in contrast to the hypointense pattern of nonirradiated marrow. The degree of fatty replacement was objectively assessed with chemical shift imaging, comparing patients to age-matched healthy volunteers. The authors found an increase in relative fat signal of 37% in the thoracic spine and 34% in the lumbar spine. The relative fat signal of nonirradiated pelvic and femoral marrow was decreased …
Darstellung des Blutflusses in den Gebärmutterarterien und im normalen sowie malignen Gebärmuttergewebe mittels einer 2D-Multiphasen-Tagging-Technik
PURPOSE The aim of this pilot study was to evaluate a 2D-STAR technique as a non contrast-enhanced approach to demonstrate the uterine artery and its branches and to assess the cervical uterine blood flow in healthy volunteers and in patients with advanced uterine cervical carcinoma. MATERIALS AND METHODS Seven healthy volunteers (mean age, 29 years) and twenty-two patients (mean age, 52 years) with advanced cancer of the uterine cervix (FIGO IIB-IVA) were prospectively examined by 2D-STAR imaging at different inversion delay times (300 ms-1900 ms) which showed the passage of a blood bolus through normal and malignant tissue of the uterine cervix. RESULTS The uterine artery was well visuali…
Cervical carcinoma: standard and pharmacokinetic analysis of time-intensity curves for assessment of tumor angiogenesis and patient survival
Since detailed knowledge regarding the pathophysiological properties—which in turn are responsible for differences in contrast enhancement—remain fairly undetermined, it was the aim of this study (i) to examine the association of standard and pharmacokinetic analysis of time-intensity curves in dynamic MRI with histomorphological markers of tumor angiogenesis (microvessel density [MVD]; vascular endothelial growth factor [VEGF]) and (ii) to determine the ultimate value of a histomorphological and a dynamic MRI approach by correlation of those data with disease outcome in patients with primary cancer of the uterine cervix. Pharmacokinetic parameters (amplitude A, exchange rate constantk 21) …