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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.

A horseshoe kidney was incidentally diagnosed while performing an abdominal scan using autologous human red blood cells labeled with Tc-99m (Tc-99m RBC) on a patient with suspected gastrointestinal bleeding. This patient repeatedly tested positive on occult blood stool examinations. In the first scintigram, an increase in well-defined activity was found on the right side under the liver. This could have been caused either by bleeding of the gastric antrum or the duodenal bulb. A second abdominal scan with Tc-99m RBC revealed faint radionuclide accumulation in the shape of a horseshoe with symmetrical, well-defined activity. However, the well-defined activity decreased with time on both images, and on this basis a horseshoe kidney was diagnosed.

Although the accumulation of Ga-67 citrate in gynecomastia has been described, no researchers have reported that Ga-67 citrate accumulates in a "doughnut" pattern. Basically, gynecomastia is due to an increase of estrogens. Since estrogens accelerate the proliferation of lactiferous ducts in the center of breast, Ga-67 citrate may accumulate in it. On the hand, prolactin increases the proliferation of the glandular lobules and the acinus. When the serum prolactin increases after child birth or renal insufficiency, the image from the accumulation of Ga-67 citrate in the breast may have a "doughnut" pattern. A patient with gynecomastia had high levels estrogens because he was being treated with an estrogen medication. He was referred for liver cirrhosis. The results of the present report indicate that the "doughnut" pattern occurs in the margin of the hyperplasic glandular lobule.

A case of intestinal bleeding caused by multiple ulcerations near the terminal ileum is presented. Abdominal scanning with Tc-99m tagged red blood cells (Tc-99m RBC) demonstrated the intermittent bleeding in short intervals. Selective angiography did not demonstrate the bleeding site. Exploratory laparotomy showed 3 ulcers on the ileum at a site near the terminal ileum, with bleeding from one site. Tc-99m RBC abdominal scanning was very useful in this case for localization of the site of gastrointestinal bleeding before laparotomy.

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 case of Hashimoto's disease complicated by thyroid gland cancer, the primary site of the cancer was visualized as a cold nodule on Tc-99m pertechnetate scintigraphy, as a warm nodule on Tl-201 early imaging, and as a hot nodule on Tl-201 delayed imaging. Generally, Tl-201 shows markedly diffuse accumulation in the lesions of Hashimoto's disease. The warm nodules observed on early scans suggested similar accumulation at the sites of Hashimoto's disease and thyroid cancer. The hot nodules on delayed imaging may be due to the difference in Tl-201 washout time between the sites of Hashimoto's disease and thyroid cancer. There was markedly increased Tl-201 accumulation in bilateral cervical metastatic lymph nodes on both early and delayed images.

Kidney transplants have been evaluated using a radionuclide technique to determine perfusion index (PI), mean transit time (MTT), and the parameters in renogram curve (Tmax, T1/2, and T2/3). The values for Tmax, T1/2, and T2/3 were also determined in normal volunteers. The results indicated that the Tmax value was less than 2 minutes, one week after transplantation. The other data were within normal limits. The appearance of Tmax was very early. The early time activity curve (TAC) was quite similar to the blood disappearance curve, TAC did not have the functional-phase, so-called, 2nd-phase. These data suggested that there could be an abnormality of the renal circulation in the transplanted kidney. The suggestion offers the new finding in a field of renal transplantation using radionuclide technique.

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.

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.

Using N-isopropyl-(I-123)p-iodo-amphetamine (I-123 IMP) and gallium-67 citrate, it was possible to detect human malignant melanomas. I-123 IMP imaging was helpful in detecting melanomas occurring in the legs and arms, and the 4 hour image was better than the 1 hour image. Moreover, while gallium scintigraphy more clearly detects human malignant melanoma, I-123 IMP allows for the detection of human malignant melanoma within 1 hour after administration.

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.

Menetrier's disease is a relatively rare disease characterized by greatly enlarged gastric rugae resembling the convolutions of the brain and often associated with hypoproteinemia. Although radiographic examination of the stomach is one of the most reliable diagnostic measures of this disease, it is hard to clarify the structure of the gastric wall by this method. Ultrasonographic examination of the stomach, which has recently become more practical, has the advantage of delineating the structure of the gastric wall. We report here the ultrasonogram in a case of Menetrier's disease. The ultrasound demonstrated gastric wall thickening (pseudo-kidney sign), crinkled mucosal folds projecting into the lumen, a smooth serosal surface with a clear boundary between the adjacent organs, and a pliable gastric wall. The follow-up study revealed no changes in the sonographic appearance. The diagnostic value of ultrasound in Menetrier's disease and its limitations are discussed.

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.