Medical imaging by fluorescent x-ray CT: its preliminary clinical evaluation

Abstract

Fluorescent x-ray CT (FXCT) with synchrotron radiation (SR) is being developed to detect the very low concentration of specific elements. The endogenous iodine of the human thyroid and the non-radioactive iodine labeled BMIPP in myocardium were imaged by FXCT. FXCT system consists of a silicon (1 1 1) double crystal monochromator, an x-ray slit, a scanning table for object positioning, a fluorescent x-ray detector, and a transmission x-ray detector. Monochromatic x-ray with 37 keV energy was collimated into a pencil beam (from 1 mm to 0.025 mm).FXCT clearly imaged endogenous iodine of thyroid and iodine labeled BMIPP in myocardium, whereas transmissionx-ray CT could not demonstrate iodine. The distribution of iodine was heterogeneous within thyroid cancer, and its concentration was lower than that of normal thyroid. Distribution of BMIPP in normal rat myocardium was almost homogeneous, however reduced uptake was slightly shown in ischemic region. FXCT is a highly sensitive imaging modality to detect very low concentration of specific element and will be applied to reveal endogenous iodine distribution in thyroid and to use tracer study with various kinds of labeled material.

Phase-contrast X-ray imaging with a large monolithic X-ray interferometer

“…3(a). According to our previous observation with phase-contrast X-ray computed tomography, the ®brous capsule surrounding a cancer should cause contrast Takeda, Momose, Yu et al, 2000; Interference pattern obtained using the large X-ray interferometer recorded using an imaging plate. Takeda, Momose, Hirano et al, 2000).…”

“…A slice of a rat cerebellum (Momose & Fukuda, 1995) and a human metastatic liver tumor (Takeda et al, 1995) were imaged and the various structures could be revealed. Phase-contrast X-ray computed tomography (Momose, 1995) has demonstrated rabbit cancer lesions (Momose et al, 1996a,b), rat brain (Beckmann et al, 1997(Beckmann et al, , 1999 and human cancer lesions Momose et al, 1999;Takeda et al, 1998;Takeda, Momose, Yu et al, 2000;Takeda, Momose, Hirano et al, 2000). However, the available view size has been limited to 5 mm  5 mm in the previous phase-contrast X-ray imaging system (Momose, Takeda, Itai, Yoneyama & Hirano, 1998) because of the small size of the monolithic X-ray interferometer.…”

Visualization of age-dependent myocardial metabolic impairment in cardiomyopathic model hamster obtained by fluorescent X-ray computed tomography using I-127 BMIPP

“…Thus, we originally designed a fluorescent X-ray computed-tomography (FXCT) imaging system that did not require the preparation of specimens like in planar mode (Takeda, Akiba et al, 1996), and the sensitivity of the FXCT was about 80-fold higher than that of absorption X-ray computed tomography (CT) . The cross-sectional distribution of iodine in human thyroid was imaged first (Rust & Weigelt, 1998;Takeda et al, 2000, and our interests are now towards the use of FXCT in determining tracer elements including iodine. Since radio-iodinated I-5-( p-iodophenyl)-3-(R,S)-methylpentadecanoic acid ( 123 I-BMIPP) is a potential tracer for detecting the myocardial fatty acid metabolism in clinical SPECT studies (Fujibayashi et al, 1990;Inoue et al, 2007;Ogata, 1989;Thet-Thet-Lwin et al, 2003), we chose to use this agent for FXCT imaging.…”

Radiation background and beam quality in secondary X-ray imaging for human angiography with Au as contrast agent

“…It would be smaller or would be altogether absent if either the object to be imaged were less wide, or if it were to be shifted slightly forward from the center, or if Df were increased (vanishing for Df ¼ 2p). While these considerations indicate that there is room for design improvement, 18 our purpose is to evaluate feasibility rather than optimize performance, therefore, here we will not pursue this further.…”

“…Recently, very significant progress has been achieved by applying this technique to the detection of trace materials, particularly in medical imaging, and demonstrating its high sensitivity [15][16][17][18]. To accomplish that goal, a well monochromatized and collimated primary X-ray beam irradiates the sample.…”