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To investigate changes in college student perceptions of radiation over time, we performed questionnaire surveys in November 1992 and January 2000. The subjects were students of the humanities or social sciences, numbering 290 (19.1±1.1 y) in 1992 and 226 (19.9±2.0 y) in 2000. The questionnaires had two sections. First, the students were asked to list words which they associated with the stimulus word“radiation”. Next, they performed a ten stage-evaluation (0 to 10 points) of the degree of“familiarity”, “danger”, “usefulness”, and“acceptability”with regard to 26 items which included radiation and things related to radiation. In both surveys, the top three responses to the stimulus word“radiation”, were“roentgen”, “atomic bomb”, and“nuclear power”. The students in 2000 associated the word“radiation”with words such as“Tokaimura”which were related to recent accidents. The evaluation ratings of“familiarity”, “usefulness”, and“acceptability”for nuclear power changed significantly between 1992 and 2000 (p

To evaluate the therapeutic effects of percutaneous nephroureterolithotomy, the renal function of eleven patients with renal calculi was studied, pre- and post-intervention. Renal function was determined, by renal scintigraphy with the renal agent, Tc-99m diethylenetriaminepentaacetic acid (DTPA). In each renal scintigram the renogram curve was analyzed and the following were determined by deconvolution analysis; the renal fraction of blood flow (RFBF), DTPA-glomerular filtration ratio (GFR), and the renal mean transit time (MTT). The successful results in percutaneous nephroureterolithotomy (PNL) was proven using the radionuclide technique in most cases. From these results it can be concluded that renal scintigraphy is an effective procedure to evaluate the effect of PNL for treating renal calculi and secondary hydronephrosis.

The temporal image subtraction technique was applied to bone scintigraphy, using Photoshop (commercially available image processing software) and Morpher (public domain warping software). For the temporal subtraction images, 81 subtraction images (19 cases) were prepared by a method used to subtract the previous images from the current ones. Registration of the current and previous images was performed by manual operation using Photoshop, and warping was done using the warping function of Morpher. In addition, difference images prepared after correcting the distributions of radioactive isotopes of the current and previous images using the count of the pelvic region were also examined. Compared with manual operation, alignment of images by warping improved registration and reduced the generation of pseudo-images of subtraction images. The rate of identification of abnormal accumulation-enhanced regions and subjective evaluation by doctors was improved for warping more than for manual operation. Furthermore, abnormal hot regions, which are difficult to find in film images, could be found in three subtraction images. In addition, it was confirmed that abnormal hot regions become more visible in many cases by preparing subtraction images after correcting the count between images using the count of the pelvic region. Thus, it is suggested that the temporal image subtraction technique in bone scintigraphy enables more accurate observation of enhancement of or changes in abnormal hot regions, which will support diagnostic reading. It is considered that enhancement of or changes in abnormal hot regions will be more accurately understood through further detailed discussion in the future.

In this study, we examined the usefulness of whole body coronal images and whole body cine display MIP images (CMIP) upon which image processing was carried out after whole body SPECT in comparison to the usefulness of whole body images (WB/SC) compensated by scattered radiation in tumor/inflammation scintigraphy with 67Ga-citrate (67Ga). Image interpretation was performed for the 120 patients with confirmed diagnoses, and the accuracy of their diagnoses was studied by three nuclear medical physicians and two clinical radiological technologists by means of sensitivity, specificity and ROC analysis. The resultant data show that sensitivity, specificity, accuracy and the area under the ROC curve Az in the WB/SC were approximately 65%, 86%, 74% and 0.724, respectively, whereas sensitivity, specificity, accuracy and Az of the image reading system in which CMIP is combined with whole body coronal images reconstructed by the OS-EM method were approximately 93%, 95%, 94% and 0.860, respectively. Furthermore, coronal images reconstructed by the OS-EM method tended to be superior to those produced by the FBP method in both diagnostic accuracy and ROC analysis. In conclusion, the image reading system in which CMIP is combined with whole body coronal images reconstructed by the OS-EM method was shown to be superior in diagnostic accuracy and ROC analysis. Our data suggest that whole body SPECT is an excellent technique as an alternative to WB/SC.

Radioactivity after administration of 123I-sodium iodide was measured in breast milk samples obtained from a patient with postpartum thyroiditis. The breast milk was collected over 93 h during the infant's regular feeding times. The radioactivity in the breast milk was calculated with a 123I capsule of the same lot number as the standard source. 123I was excreted exponentially with an effective half-life of 5.5 h; 2.5% of the total radioactivity administered was excreted in the breast milk over the 93 h, 95% of which was excreted within the first 24 h, and 98.2% within 36 h. The first milk sample collected at 7 h after administration of the radiopharmaceutical contained 48.5% of the total radioactivity excreted. We estimated the potential absorption of radioactivity to an infant's thyroid in uninterrupted breast-feeding to be 30.3 mGy. With a 24-hour interruption, the absorbed radioactivity would be 1.25 mGy; with a 36-hour interruption, it would be 0.24 mGy. According to our calculations, breast feeding should be curtailed for 36 h to reduce the infant's exposure to 123I radioactivity. By using a correction factor based on maximum radioactivity from another 123I capsule of the same lot, we were able to ascertain the appropriate protocol for our patient and establish a measurement method that can be applied in similar clinical situations.

Six patients with cardiomyopathy were imaged following intravenous injection of an indium-111 labeled monoclonal antibody directed against the heavy chain of cardiac myosin. Two patients had hypertrophic non-obstructive cardiomyopathy (HNCM), two patients had dilated cardiomyopathy (DCM), and two patients had specific heart muscle disease. One of 2 patients with HNCM and one of 2 patients with DCM had a positive antimyosin scan. The 2 patients with specific heart muscle disease manifested persistent blood pool activity of the antibody, thereby precluding interpretation of the images. The present report demonstrates that antimyosin antibody imaging may provide evidence of myocardial injury, or necrosis in some patients with cardiomyopathy.

To evaluate the primary site, pulmonary hilar, and mediastinal lesions in patients with lung cancer, thallium-201 using single-photon emission computed tomography (SPECT) was used as a tumor agent. The study population consisted of 7 patients (5 men and 2 women), aged 57 to 82 years (mean 68). Tl-201 tomography imaged positive at the primary site in all patients with lung cancer. The images demonstrated the tumor and/or mediastinal lymph nodes that were greater than 2.0cm. In particular, each tomograms facilitated the identification of the Tl-201 increased uptake in proportion to primary site. The short waiting period after injection with Tl-201 clearly offers a major advantage over alternative tumor imaging agents, such as Ga-67 or radiolabeled monoclonal antibodies. Furthermore, Tl-201 SPECT may be useful to detect the tumor and/or mediastinal lymph nodes in patients with lung cancer.

The recent expansion of interventional cardiovascular techniques has stimulated the development of non-invasive cardiac studies, to evaluate the outcome of the interventional therapy. Radionuclide ventriculographic technique provides to quantify global left ventricular systolic/diastolic performance, and evaluate the regional left ventricular wall motion during rest or exercise. This concept was extended from the "bedside" to the ambulatory environment with the description of a battery powered device, the radionuclide ventricular function monitor. To assess the performance of cardiac function using radionuclide ventriculography to that using the ambulatory ventricular function monitor, the systolic and diastolic function were measured at rest in a series of healthy volunteers (n = 10) and in patients with cardiovascular disease (n = 23). Seventeen patients had coronary artery disease (CAD) with prior myocardial infarction, three patients had coronary artery disease, and three patients had dilated cardiomyopathy. The 23 patients manifested a wide variation in LV systolic function. The relationship between the multiple gated acquisition (MUGA)-ejection fraction and the ambulatory ventricular function monitor-ejection fraction correlated well (r = 0.90). As a complement to the radionuclide perfusion studies, cardiac blood pool imaging and radionuclide ventricular function monitoring allow for through non-invasive description of cardiac physiology and function in patients with various cardiac disorders.

In a DAB-hepatoma organic tumor, Ga-67 accumulated markedly in the hepatocellular carcinoma with scant stroma but not in the cholangioma that was rich in connective tissue. No granulation tissue was formed around the tumor. In transplanted tumors (Ehrlich's tumor and Sarcoma 180), Ga-67 accumulated in the granulation tissue within the fibroblasts, leukocytes and capillaries surrounding the tumor, rather than in the tumor. In inflammatory lesions, Ga-67 uptake was similar in granulation tissue with large numbers of phagocytes, such as leukocytes and histiocytes, and capillaries. There was a very good correlation between the degree of Ga-67 uptake and of cellular infiltration and the proliferation of capillaries. Ga-67 uptake, both in inflammatory lesions and in transplanted tumors, was observed in the granulation tissue. This result implies that the mechanisms of Ga-67 uptake in tumor and inflammatory tissues are not the same, because Ga-67 accumulated in the DAB-hepatoma that had no inflammatory granulation tissue. This study indicates that a non-transplanted tumor is required to study Ga-67 accumulation in tumors, as different results may occur in tumors with and without inflammatory granulation tissue.

We studied the influence of pH, using 131I solution, as for a skin contamination and obtained the following results : 1) in regard to alkalinity, the skin surface contamination was large and in regard to acidity, the contamination in skin surface was less than in skin deep part. 2) the internal contamination in acidity was larger than in alkalinity.

The recognition of signal was varied by the chart form and in proportion as signal and S/B ratio increase, the subject image become more clear. The subject image less than some size could not recognized even in proportion as signal and S/B ratio increase.

The use of gadolinium (Gd) as a “band pass” filter for the X-ray contrast examination is discussed. Vinyl tubes filled with iodine solution were placed in a water phantom (15 cm thickness). When this phantom was exposed to a 70 kVp X-ray filtered by a Gd-filter, to give an equal film density as an aluminium (Al) filter, the surface dose was reduced by 45 % . The effective attenuation coefficient of the iodine for an 80 kVp X-ray filtered with a Gdfilter of 0.4 mm thickness corresponds to that for a 70 kVp X-ray filtered with an Al-filter of 2 mm thickness. These results indicate that a decrease of skin dosage and an increase of film contrast are obtained by using a Gd-filter for the X-ray examination with an iodine contrast medium.

The heart-to-liver (H/L) uptake ratio in rats was determined 8 min after the rectal administration of 201Tl. Apart from normal controls, three groups of rats were examined; these were composed of animals with induced (1) acute hepatic damage, (2) liver cirrhosis, and (3) partial portal-vein ligation. After the rectal administration of 201Tl, 51Cr-labeled microspheres were injected into the spleen. The radioactivity of the removed liver, lungs, and heart was determined in a gamma-well scintillation counter, and the radioactivity of 201Tl and the 51Cr-labeled microspheres was separately calculated using simultaneous equations derived from the results of a preliminary experiment. The H/L ratios (201Tl) in the normal controls and the animals with acute hepatic damage were not significantly different; however, there was a positive correlation (P less than 0.01) between the H/L ratio and the shunt index (51Cr microspheres) in three groups, i.e., normal controls, liver cirrhosis, and partial portal-vein ligation.

On removing radioisotopes that contacted with skin, a contamination removal reagent was used. If radioisotopes was handled direct after use of the contamination removal reagent, the internal contamination got to be increased. For the prevention of it, hand cream was effective because the hand cream applied after use of the contamination removal reagent was reduced the internal contamination to 1/5 compared with no use of hand cream. The application of hand cream after use of the contamination removal reagent was simple way to prevent the internal contamination.

The renal circulation of patients with essential hypertension and renovascular hypertension was evaluated using 99mTc-DTPA. The first renal peak count (the first Cmax; FCmax), time phase distribution (the first Tmax; FTmax), and blood velocity (the FCmax/FTmax) were calculated by digital imaging. This yields a visual image of the renal circulation. We consider that the increase in the renal first pass blood flow in patients with essential hypertension is best observed pixel by pixel. The FCmax and FCmax/FTmax images before and after treatment by percutaneous transluminal renal angioplasty in patients with renovascular hypertension clearly show its therapeutic effect. The FI technique, therefore, has the advantage that it can be performed at the same time as the conventional routine examinations of renal function. This makes it very useful clinically.

Functional Image (FI), which represents dynamic local renal function in one image, has been made possible only by digital image processing. The first FT obtained by rapid bolus injection of the radiolabeled medium is considered to be useful for evaluation of initial local renal blood flow. FT has the advantage that it can be performed simultaneously with conventional rou-tine examinations of the renal function.

Bones of immature rabbits were irradiated during the growth period, and followed with bone scintigraphy using Tc-99 m methylene diphosphonate. The accumulation of the radionuclide was decreased in the irradiated bone at an early period as compared to the control side, and the decrease was more pronounced as the dose of irradiation was increased. In the groups irradiated with less than 4, 000 rad, the accumulation ratio reached a minimum at 5 weeks and was followed by a gradual recovery. In the group irradiated with 6, 000 rad, the recovery was small; and no recovery was observed in the 8, 000 rad group. These changes were compared to the inhibition of the longitudinal growth of the bone. The accumulation ratio for the radionuclide was a more sensitive index of the effect of radiation than the growth rate.