Search

The aim of this study was to examine the value of an additional atropine injection in patients who do not achieve an adequate heart rate during dobutamine infusion for myocardial perfusion SPET (single photon emission tomography). Patients undergoing dobutamine myocardial SPET who failed to achieve > or = 85% of their age-predicted maximal heart rate at the end of dobutamine infusion (D protocol) had a second dobutamine myocardial SPET study on a separate day with the addition of an atropine injection during the dobutamine infusion (D + A protocol). Twenty-nine patients were studied. 201Tl was used in 27 patients and 99Tc(m)-MIBI in two patients. All patients underwent coronary angiography and significant coronary artery disease was found in 19 of 29 patients. The mean heart rate obtained at the peak of dobutamine infusion in the D + A protocol was significantly higher than that in the D protocol (153.8 +/- 13.8 vs 117.5 +/- 15.3 beats min[-1]). The D + A protocol resulted in a higher diagnostic sensitivity for the detection of stenosed coronaries compared with the D protocol (87 vs 80%, P > 0.05) without changing the specificity (89% for both protocols). On the other hand, the frequency of side-effects and ECG changes during the D + A protocol was higher than that with the D protocol (32 vs 47). In conclusion, the addition of an atropine injection during dobutamine infusion resulted in a higher diagnostic sensitivity for identifying stenosed coronaries compared to dobutamine alone.

Radionuclide scanning with tumour-seeking agents such as pentavalent technetium-99m dimercaptosuccinic acid [99mTc(V)-DMSA], thallium-201 and technetium-99m sestamibi (MIBI) has been reported to be useful in the detection of medullary thyroid carcinoma (MTC). We undertook a study in 14 MTC patients to determine the comparative imaging potential of 201Tl, MIBI and 99mTc(V)-DMSA in the detection of recurrent or metastatic MTC. All patients underwent total thyroidectomy and had persistently elevated serum calcitonin levels after the surgery. Scintigraphic studies were carried out 20 min after the injection of 111 MBq of 201Tl or 555 MBq of MIBI and 2 h following the injection of 370 MBq of 99mTc(V)-DMSA. All scintigraphic findings were correlated with contemporaneous CT or MRI studies. CT, MRI and bone scans showed 42 (26 bone, 16 soft tissue) metastatic sites in 11 of the 14 patients. In the remaining three patients no lesions were detected during diagnostic evaluation. 99mTc(V)-DMSA showed all of the soft tissue metastases but could not show two bone lesions. On the other hand, MIBI imaging was false-negative in 22 (52%) sites and 201Tl was false-negative in 34 (80%) sites. Overall, lesion detection sensitivities for 99mTc(V)-DMSA, MIBI and 201Tl were 95%, 47% and 19% respectively. We conclude that 99mTc(V)-DMSA is clearly superior to MIBI and 201Tl in the follow-up of MTC patients.

Technetium-99m-ethylenedicysteine (99mTc-EC) captopril scintigraphy performed in a patient with severe hypertension revealed increased parenchymal retention in the left kidney, suggesting renal artery stenosis. After angiographic confirmation of renal artery stenosis, percutaneous transluminal angioplasty (PTA) was performed on the left renal artery. Captopril scintigraphy after PTA showed normal findings with no evidence of parenchymal retention, consistent with reversal to normal kidney functions. In light of this case of renal artery stenosis, it was concluded that 99mTc-EC can be used successfully as a potential renal agent in the diagnosis and follow-up of renovascular hypertension.

SummaryGlutathione labelled with 99mTc was used to study blood clearance and normal distribution in 3 healthy volunteers and in 10 patients with biopsy-proven tumors in the head and neck region. Static scintigrams were obtained at 1, 3, 6, and 24 h. ROIs over tumors and normal soft tissues were compared to obtain T/N ratios. In normal subjects blood clearance reached a plateau at 6 h; no radioactivity accumulation in the head and neck region was observed. Only the cardiac blood pool, the liver, the kidneys and the urinary bladder were evident. Excretion was via the kidneys. Malignant tumors and metastases were well visualized in 7 patients (true-positive), starting at 1 h. The mean T/N ratio was 2.69 ± 0.77. The best images were obtained at 3-6 h. 1 false-positive (granula-matous reaction), 1 false-negative (malignant epithelial tumor in the radix of tongue) and 1 true-negative (angiofibroma) results were obtained. 99mTc-GSH is a potential radiopharmaceutical for the scintigraphic visualization of head and neck tumors. Further clinical studies are warranted to show its sensitivity and accuracy.

The role of gallium-67 scintigraphy in Behcet's uveitis was evaluated. Pattern and quantitative comparisons were made in patients with active Behcet's uveitis, uveitis in remission, and ocular sarcoidosis. There were statistically significant differences between groups. Our data suggest the persistence of inflammatory cells even in remission stages of Behcet's uveitis. In the presence of certain patterns, gallium-67 scintigraphy can make limited contributions in the evaluation of Behcet's disease or sarcoidosis.

Twenty-eight patients were studied for regional cerebral blood flow changes as a result of chronic alcoholism. After the administration of 550 to 600 MBq Tc-99m HMPAO, tomographic slices were obtained using a SPECT camera. Eight regions per hemisphere were drawn on each transaxial section, and tracer redistribution was calculated for each region. Region-to-whole slice ratios were determined for each patient. Patients had significantly decreased frontal/whole slice (1 +/- 0.02) ratios in comparison with a normal group (p less than 0.01). Twenty-four out of 26 patients (85.7%) demonstrated abnormal rCBF. Eighteen out of 28 (64.3%) showed activity lower in the left hemisphere than in the right. Using CT parameters, 60% of the patients had either sulcal widening and/or ventricular enlargement. The frontal region and the left hemisphere were more affected by alcohol than other regions. More cerebral blood flow changes than morphologic changes were found caused by alcoholism.

Arterial and venous systems are the main points for the evaluation of vasculogenic impotence. To evaluate both of these systems in the same study we propose a dual radioisotopic study in which technetium-99m (Tc-99m) and xenon-133 (Xe-133) were used. The changes in Tc-99m and Xe-133 radioactivities administered intravenously and intracavernously, respectively, were monitored before and after intracavernous papaverine injection. These changes were determined as time activity curves, which were generated from the region of interest over the penis. A Tc-99m penogram index derived from the Tc-99m time activity curve was significantly different in the control and arteriogenic impotence groups (131.67 +/- 74.6 versus 62.94 +/- 51.6, p < 0.01). A meaningful correlation between Tc-99m penogram index results and duplex ultrasonographic findings were observed (r = 0.905). Xe-133 penogram index, derived from the Xe-133 washout curve was significantly different in the control and venogenic impotence groups (-25.65 +/- 24.9 versus -56.09 +/- 13.4, p < 0.01). Also, a meaningful correlation was obtained between pharmacocavernosometry and Xe-133 penogram index results of venogenic impotent patients (r = 0.86). These findings suggest that the dual radioisotopic study will be a useful technique in the evaluation of the entire vascular system of the penis, since it is a noninvasive method.

Glucose phosphate (GP) labelled with 99mTc was used to obtain scintigraphic images of bone lesions in one group of patients (n = 28) and of lung tumors in another (n = 35). All bone lesions detected by 99mTc-MDP were also demonstrated by 99mTc-GP; all lung tumors except 4 were detected by 99mTc-GP, the failure rate being about the same as that for 67Ga. The use of 99mTc-GP is preferable to that of 99mTc-MDP because the former does not accumulate in normal bone; the advantage of 99mTc-GP over 67Ga lies in its better physical characteristics and in the fact that the result of the study is available within a few hours rather than three days.

Nine maxillary sinuses of 8 patients who had undergone Caldwell-Luc surgery (CWL) were injected with 100-125 µCi 99mTc-DTPA in 0.2 ml from the gingivobuccal sulcus, passing through the canine fossa window. Sinus half-emptying times and percent contribution of the natural ostium (NO) and the nasoantral window (NA) to the clearance from the sinus were calculated, using time-activity curves as well as the activity of cotton wool plugs placed into the middle and lower conchae. Mean half-emptying times in patients in whom the mucosa had been removed were shorter than those in patients in whom it had been left in place. In the former group percent drainage through the NO was higher than that through the NA whereas in the latter group the opposite was the case. These findings are consistent with the thesis that if the mucosa is retained, the ciliae continue their sweeping action towards the NO but if it is removed the NA gains importance in the drainage. This method is promising for the evaluation of maxillary sinus drainage following CWL.

A 34-year-old woman with severe hypertension underwent Tc-99m ethylenedicycteine (Tc-99m EC) captopril renal scintigraphy. There was bilateral parenchymal retention of the tracer suggesting renal artery stenosis. Angiography confirmed bilateral renal artery stenosis and also demonstrated contour irregularities of the abdominal aorta, and stenosis in mesenteric and subclavian arteries with increased collateral circulation consistent with Takayasu's arteritis. In light of this case of renal artery stenosis, it was concluded that Tc-99m EC can be used successfully as a potential renal agent in the diagnosis of renal involvement in patients with Takayasu's arteritis.

SummaryA sequential 99mTc-MAG3 renogram of a 20-year-old male who received a kidney from a living related donor is presented. Pre-transplant angiography of the donor showed the kidney had a single renal artery with upper and lower branches. The transplantation procedure was uneventful, allowing rapid simultaneous perfusion to the entire kidney. The first scan performed 2 days after the transplantation was normal except for retention of the radiotracer at the upper pole of the kidney. The renal collecting system was normal and no signs of dilatation or obstruction were noticed on ultrasonographic examination. A follow-up scan done on the 5th day of transplantation showed almost complete evacuation of the parenchymal retention previously seen on the upper pole of the kidney. This unusual finding was consistent with segmental acute tubular necrosis (ATN) of the upper pole of the kidney and showed that ATN might involve only a portion of a kidney in spite of the existence of a single artery of the transplant.

We attempted to ascertain the impact of Co-60 conventional external radiotherapy (cRT) on the perfusion of normal brain tissue in relation to the radiation doses delivered to the tumors in patients with primary brain tumors.After surgery 18 patients (pts) were due to undergo cRT with a total dose of 5400- 6400 cGy. All the patients had a Tc-99m-HMPAO SPECT study prior to cRT (basal), 15th and 30th days of cRT as well as 1 (in 6 pts), 3 (in 9 pts), and 6 (in 3 pts) months after cRT. For quantitative evaluation, the entire set of transverse slices were divided into 4 regions as frontal, parietal, occipital and temporal regions by means of a computer software program. Semi-automated quantification was performed on a total of 1392 regions in 87 studies to determine left to right ratios. An interregional difference of at least 10% was considered abnormal.After elimination of tumor sites, 80 normal brain regions showed decreased perfusion after cRT. The percent decrease in perfusion was (mean 22.5+/-9.9) significantly higher in areas irradiated with doses3000 cGy (p0.05).cRT has adverse effects on the perfusion of normal brain tissue for doses500 cGy. Our findings justify treating patients with small and limited lesions with stereotactic radiotherapy in order to minimize the adverse effects of cRT on normal tissues.

A 60-year-old man with primary splenic hemangiosarcoma (PSH) presented with weakness, weight loss, abdominal pain, and anemia. Physical examination revealed hepatomegaly, ascites, and firm, huge splenomegaly. Ultrasonography showed many nodular structures characterized by hypoechogenic and hyperechogenic areas. The patient also had portal hypertension, which was confirmed by physical findings and by measurement of portal vein pressure during operation. A liver-spleen scan using Tc-99m sulfur colloid and Tc-99m labeled heat denatured erythrocytes failed to demonstrate any splenic uptake, a reliable feature of functional asplenia. Although on a total body scan with Ga-67 citrate there was no splenic uptake, there was gallium uptake in the liver, where the presence of the metastatic lesion was histopathologically verified and confirmed by operation. There was also uptake in the middle zones of the lungs. Ga-67 citrate imaging appears to be helpful in the diagnosis of metastasis of PSH, and PSH can rarely cause portal hypertension.

The aim of this investigation was to test for the scintigraphic detection of metastases of malignant melanoma with a new radiopharmaceutical, 99 Tc m -glutathione ( 99 Tc m -GSH), in comparison with 99 Tc m -anti-melanoma antibody ( 99 Tc m -AMAb). Glutathione was labelled with 99 Tc m by a Sn 2+ reduction method with an efficiency of > 99% as determined by instant thin layer chromatography (ITLC). Anti-melanoma antibody was obtained as a kit from SORIN (Italy) and labelled with 99 Tc m O - 4 . Forty-three patients with a total of 55 biopsy-proven metastatic melanoma foci, 1 ocular melanoma and 20 benign pathologic foci, also confirmed by ultrasound, computed tomography and magnetic resonance imaging, were included in the study after giving their informed consent. Following the intravenous (i.v.) injection of 500 MBq 99 Tc m -AMAb, scintigraphic images of the involved areas were obtained 6 h post-injection. Three days later, the same patients were given 500 MBq 99 Tc m -GSH i.v. and images were obtained 6 and 24 h post-injection. The images were classified as positive (focal abnormal accumulation) or negative. Quantitative evaluation was also applied. Regions of interest were drawn over the involved areas and nearby soft tissues and the target-to-nontarget (T/NT) ratios obtained with 99 Tc m -AMAb (T/NT: 1.92 ± 0.2) and 99 Tc m -GSH (T/NT: 1.84 ± 0.2) were compared (0.1 < P ≤ 0.3). The sensitivity (and specificity) of 99 Tc m -AMAb and 99 Tc m -GSH in the detection of malignant melanoma metastases were 91% (95%) and 84% (90%), respectively. Compared with 99 Tc m -AMAb, the advantages of 99 Tc m -GSH are lower levels of blood radioactivity, lower costs and easy in-house preparation. In conclusion, our results show that 99 Tc m -GSH is a potentially useful radiopharmaceutical for the detection of metastases of malignant melanoma.

The authors present a prospective analysis of Tc-99m MDP and Tc-99m citrate scintigraphy in 29 patients who were clinically suspected of having chronic osteomyelitis. All of the patients showed increased Tc-99m MDP uptake on bone scintigraphy involving the area of concern. However, Tc-99m citrate scintigraphy clearly identified the patients with osteomyelitis (N = 18) confirmed either by biopsy or clinical follow-up. Eleven patients who were free of osteomyelitis showed only minimal radiotracer uptake on Tc-99m citrate scintigraphy. These patients had other benign musculoskeletal diseases that were diagnosed by other imaging modalities. In addition to visually interpreting the scintigraphic images, a semi-quantitative analysis was performed by drawing regions of interest over the areas involved and the normal contralateral side, and patients with osteomyelitis were found to have lesion to nonlesion ratios of greater than 1.70. Because Tc-99m MDP is a nonspecific radiopharmaceutical for the evaluation of bone infection, other imaging agents have been investigated. Tc-99m citrate is a small molecule that makes it suitable to penetrate injured capillaries to the edema fluid known to be present in areas of infection. The authors conclude that Tc-99m citrate is a promising agent for localizing and showing the extent of bone infection that will help the surgeon to determine areas of debridement before surgery.

Since somatostatin has been reported to have a negative inotropic and chronotropic effect on atria and positive inotropic effect on ventricle, present study was designed to investigate the acute effects of somatostatin analogue SMS 201-995 infusion on the left ventricular function in healthy volunteers. After labeling the autologous red blood cells with 750-1000 MBq 99mTc-pertechnetate, ECG-gated radionuclide ventriculography was performed. Using Fourier analysis of the left ventricular time-activity curve, ejection fraction (EF), peak ejection rate (PER), peak filling rate (PFR), time to end-systole (TES) and normalized TES/T values were calculated. Study group consisted of 12 healthy volunteers. Somatostatin analogue SMS 201-995 infusion was given at a rate of 100 micrograms/h during 2h. Baseline, 1st, 2nd h and 4th h imagings were done using the same protocol. Simultaneously heart rate and blood pressure were recorded. The difference between parameters was tested using Kruskall-Wallis test. The mean heart rate, systolic and diastolic blood pressures and did not show any statistically significant change during the somatostatin analogue infusion and 2h later in comparison to baseline values. The mean PER and PFR had a slight decrease at the first hour of infusion, but the change was not significant. However, the significant correlation of PER values with heart rate, EF and TES observed at baseline study were disappeared during the infusion. These results indicate that somatostatin analogue infusion does not appear to change the left ventricular systolic and diastolic function in healthy persons significantly.

To evaluate the behavior of circulating endothelin and atrial natriuretic peptide (ANP) during coronary artery bypass graft (CABG) surgery, blood samples from patients with coronary artery disease (n = 8) were investigated before, during and after operation. Plasma levels of endothelin and ANP were determined using the radioimmunoassay method. Baseline plasma levels were compared to those of normal volunteers (n = 6). Left ventricular function at rest and as a response to isometric exercise was evaluated using radionuclide ventriculography before and after coronary bypass surgery. The mean endothelin value was found to be within normal limits, however the mean ANP value was slightly higher than control. Patients had significantly improved left ventricular systolic and diastolic function after surgery. The mean endothelin level was higher than initial values immediately after extra-corporeal circulation and returned to initial values in two hours. However, ANP values were increased and remained higher than initial values. Baseline endothelin values were negatively correlated with systolic function parameters, whereas endothelin and heart rate had a positive correlation before extra-corporeal circulation. Coronary artery bypass graft surgery may cause an increase in the circulating endothelin level either due to endothelial injury or due to myocardial ischemia and hypothermia. Following surgery, increased endothelin levels returned to normal values immediately.

A patient with parathyroid cancer is presented who underwent Tc-99m MIBI scintigraphy. The Tc-99m MIBI image demonstrated increased accumulation of activity at the lower pole of the left thyroid lobe which was later confirmed as a parathyroid cancer. Uptake by parathyroid cancer must be kept in mind as a cause of increased Tc-99m MIBI accumulation when a disease is in question in the thyroid or parathyroid gland.

In this study we investigated bleomycin-induced pulmonary toxicity in patients with germ-cell tumour by means of technetium-99m diethylene triamine penta-acetic acid aerosol scintigraphy. Twenty untreated patients who had no clinical or radiological evidence of pulmonary disease received four courses of etoposide, cisplatin and bleomycin chemotherapy. Aerosol lung scintigraphy and pulmonary function tests were performed in all patients before bleomycin treatment and after administration of 180 and 360 mg bleomycin. On the basis of the scintigrams the percentage decline in activity per minute (Kep) was evaluated, which represented an accurate parameter of lung membrane permeability. Pretreatment Kep values (0.891 +/- 0.286) were significantly lower than those obtained following 180 and 360 mg bleomycin treatment (1.176 +/- 0.336 and 1.389 +/- 0.477, respectively; P0.0005). The Kep values obtained with 180 and 360 mg bleomycin treatments were also significantly different (P0.005). In contrast, no significant change was observed in the results of pulmonary function tests. Our results demonstrate that evaluation of the pulmonary clearance of 99mTc-DTPA represents a useful means of monitoring the functional status of the lung epithelial membrane during bleomycin treatment. Further prospective studies are needed to assess the relationship between increase in permeability and development of lung toxicity in order to decide which patients should discontinue bleomycin therapy.

The tumor markers; CEA, CA 19-9, CA 125, CA 15-3 levels in effusions caused by some common malignant tumors, such as breast, gastrointestinal tract and ovarian cancers were compared to the serum levels of the same group of patients. Thirty three patients were included in the study group. Comparison with benign effusions (12 patients) was also carried out. Corresponding tumor markers designated for each tumor type were analyzed besides CEA which was measured in all patients. Although we got more positive results in malign effusions than the sera, this difference was not statistically significant (p>0.05). But mean values of tumor markers were found to be statistically higher in malign effusions when they are compared to the sera of the same patients and to the benign effusions of control group (p < 0.05). As a result, determination of tumor markers in the effusions is more sensitive than in the sera and this method is also useful for differential diagnosis of benign and malign effusions.

Regional cerebral blood flow was investigated in 14 patients with major depression diagnosed according to the DSM-III-R criteria (six patients with single and eight patients with recurrent episodes) and in ten healthy volunteers. The mean ages of the patients and the controls were 33.5 +/- 2.7 and 31.6 +/- 2.6 years, respectively. The severity of the depression was assessed using the 17-item Hamilton Depression Scale (mean: 23.2 +/- 1.5). None of the patients was under medication. After administration of 500 MBq technetium-99m hexamethylpropylene amine oxime, a single photon emission tomography study was performed and then transaxial, sagittal and coronal slices were obtained. For the semiquantitative analysis of the data, the ratios of the mean counts/pixel to the whole slice were calculated for 24 regions on three consecutive transaxial slices in the orbitomeatal plane. Additionally, left/right and frontal/occipital ratios were calculated. Both sides of the temporal region had a significantly decreased cerebral blood flow (CBF) when compared to the controls. The left/right ratio of the prefrontal region was also significantly lower in the patients than in the controls. The Hamilton score had a negative correlation with blood flow in the anterofrontal and left prefrontal regions. According to our results, regional CBF seems to be decreased in the left prefrontal and in both temporal regions in major depression. The severity of depression is correlated with the reduction in CBF in the regions of the anterofrontal and left prefrontal cortex.

Regional cerebral blood flow was investigated in 14 patients with major depression diagnosed according to the DSM-III-R criteria (six patients with single and eight patients with recurrent episodes) and in ten healthy volunteers. The mean ages of the patients and the controls were 33.5 +/- 2.7 and 31.6 +/- 2.6 years, respectively. The severity of the depression was assessed using the 17-item Hamilton Depression Scale (mean: 23.2 +/- 1.5). None of the patients was under medication. After administration of 500 MBq technetium-99m hexamethylpropylene amine oxime, a single photon emission tomography study was performed and then transaxial, sagittal and coronal slices were obtained. For the semiquantitative analysis of the data, the ratios of the mean counts/pixel to the whole slice were calculated for 24 regions on three consecutive transaxial slices in the orbitomeatal plane. Additionally, left/right and frontal/occipital ratios were calculated. Both sides of the temporal region had a significantly decreased cerebral blood flow (CBF) when compared to the controls. The left/right ratio of the prefrontal region was also significantly lower in the patients than in the controls. The Hamilton score had a negative correlation with blood flow in the anterofrontal and left prefrontal regions. According to our results, regional CBF seems to be decreased in the left prefrontal and in both temporal regions in major depression. The severity of depression is correlated with the reduction in CBF in the regions of the anterofrontal and left prefrontal cortex.

The regional clearance of 133Xe from the lungs after intravenous administration as well as following rebreathing was assessed in 7 normals and 18 patients with various lung disorders. Each lung was divided into three zones as upper, middle and lower. Regional ventilation (V) and regional perfusion (P) were determined using the area under the first peak at the beginning of the ventilation study and the area under the peak after intravenous administration, respectively. Slopes were calculated using the first exponential of the washout curve. Absolute slope values of the wash-out curves after perfusion (Pwo) and ventilation (Vwo) were expressed as a percentage of the total for each lung. Correlation coefficients between V and Vwo, V and Pwo, P and Pwo were .695, .584 and .882 in normals and .610, .461 and .685 in patients, respectively. It is concluded that Pwo is influenced by both perfusion and ventilation; it may reflect the fractional contribution to the gas exchange and can be used in the prediction of residual lung function after lung resection.

Tc-99-m-latex particles (LP) is a newly developed radiopharmaceutical for the evaluation of the gastrointestinal (GI) tract. Following oral ingestion, it passes through the entire GI tract undissolved. The purpose of the present investigation was to introduce the clinical application of Tc-99-m-LP. A group of 11 healthy volunteers was studied. Following a 12 h fast, the subjects were given 150 ml of water containing 37 MBq of Tc-99-m-LP orally. Dynamic images up to 2 h were recorded to document temporal progression of radioactivity. Static images of the abdomen and whole body were taken at intervals. In normal subjects the tracer arrival times at the caecum and sigmoid colon were 3.2 +/- 0.9 and 11.2 +/- 3.2 h, respectively. The average t1/2 value for gastric emptying, 50% colonic filling and small bowel transit time were found to be 21.6 +/- 5.6, 233 +/- 72 and 211 +/- 66.4 min, respectively. In conclusion, Tc-99-m-LP has the potential of providing functional information of the GI tract.

99mTc-Dextran (99mTc-D) was evaluated as an iliopelvic lymphoscintigraphic agent in 49 patients with malignant lymphoma and the results were compared with ultrasound (US), lymphangiography (LA) and CT where available. Scintigrams were obtained by a gamma camera at 2 h postinjection and evaluated by comparing opposite sides. In 29 of 49 patients, normal lymphoscintigrams of excellent quality, deliniating the iliopelvic and paraaortic lymph nodes bilaterally were obtained. In 20 patients lymphoscintigraphy (LS) was positive. US was performed in 46 patients, 20 had positive and 26 negative findings. There was one false positive and one false negative in LS compared to US. Ten patients had LA and 3 had CT. These results were in complete agreement with LS. There was also a positive correlation between the clinical stages and the results of LS. This study showed that 99mTc-D is an excellent radiopharmaceutical for the visualization of the lymph system with high correlation with other imaging modalities.

Twenty-nine dogs anesthetized with Na-pentobarbital were laparatomized and liver blood flow was measured by 133Xe clearance method. Fifteen dogs of the experimental group were subjected to rapid i.v. glucose tolerance test whereas 14 animals of the control group were treated identically except for infusion of glucose. It was found that the arterial and the portal venous blood glucose rose significantly during the glucose tolerance test. Liver blood flow in the experimental group was 123.8 ml/100 g L/min after operative procedures. It reached 171.9 ml/100 g L/min at 10 min after infusion of glucose (P0.01). At 20, 30, and 40 min of the test it was 145.4 (P0.05), 143.4 (P0.01), 135.1 (P0.05) mg/100 g L/min, respectively. Liver blood flow did not change significantly during the observation period in the control series. It is concluded that glucose loading may produce some metabolic effects secondary to rising liver blood flow in addition to changes induced by its rising concentration.

Pancretic blood flow rates were determined using a 133Xe washout technique in a total of 40 dogs, 14 of which were used as a control group and the remaining 26 as the experimental group. The initial pancreatic blood flow rates of control group and of the experimerntal group were 85.1 +/- 10.1 ml/100 g/min of pancreas/min and 81.1 +/- 5.4 ml/100 g/min respectively. These values were not significantly different from each other (P0.05). In the control group the blood flow was determined 3 times at 30 min intervals. These mean values were 73.0 +/- 9.4, 74.6 +/- 8.7, and 79.4 +/- 10.4 m/100 g/min respectively (P0.05). The dogs in the experimental group were bled and the peripheral arterial blood pressure was reduced stepwise to 80, 50, and 30 mm Hg. At each level at 30 min of stabilization period the pancreatic blood flow rates were 49.8 +/- 3.7, 29.3 +/- 2.3 and 20.2 +/- 2.3 ml/100 g/min respectively. These mean values were very significantly reduced compared to those of the control group at 30 min (P0.02), at 60 and 90 min (P0.001). They were also very significantly different from their own initial values (P0.001). The metabolic consequences of this reduction in pancreatic blood flow are discussed.

The water/gas, plasma/gas, erythrocyte/gas and pancreas/gas partition coefficients of133Xe were measured at 37° C using dog tissues. The pancreas/blood partition coefficients were calculated from these figures and plotted as a function of hematocrit. The133Xe pancreas/blood partition coefficient in the normal range was 1.2 ml/g.

Cyclosphospahamide, a chemotherapeutic drug, was labelled with 99 Tc m . The chemical nature and the in vitro stability of the labelled compound was tested by paper chromatography, ITLC and column chromatography. The biological distribution was studies in a group of ten normal mice and in another group of ten mice bearing an implanted fibrosarcoma. The tumour/muscle ratio was 4.1±0.2 1 hr after the injection. In cancer patients, blood clearance and excretion of the agent in urine and faeces were followed for a period of 24hr. The radioactive count rate in the normal and tumorous tissues was measured and compared in three patients with breast carcinoma. This ratio was 1.6±0.3, 1–4 hr after the injection. In scintigraphic studies positive results were obtained in 12 out of 15 patients.

Red blood cells of 10 patients were labelled with 99mTc by the in vivo method, 5 of the patients were orally administered with 400 mg potassium perchlorate at the time of stannous pyrophosphate injection and 5 ml blood was withdrawn at 10 min postinjection of pertechnetate to determine the labelling efficiency of RBC's. The RBC and plasma volumes were also determined in all patients by the 51Cr method. Our results indicated higher incorporation of injected radioactivity into RBC's in the perchlorate administered group (83.8% +/- 9.2%) compared to the other (58.5% +/- 22.0%) (P less than 0.01). The thyroid and stomach were visualized in the control group, but not in the perchlorate administered group. In routine application, 50 MUGA studies have been done with perchlorate administration with excellent results. In 60 patients without perchlorate administration previous to the present study the EF could not be determined in 6 patients (10%). Our results indicated that potassium perchlorate may be used routinely for in vivo labelling of RBC's to improve the labelling efficiency and the quality of gated cardiac imaging.

Two patients with active tuberculosis confirmed by chest radiography and positive sputum smears were included in this study to determine whether a Tc-99m labeled agent, such as DMSA or citrate could localize such lesions in comparison to Ga-67 citrate. Both patients had Tc-99m (V) DMSA, Tc-99m citrate, and Ga-67 citrate scanning at 1-day to 5-day intervals. Both patients had positive scan findings with all three radiopharmaceuticals. However, the quality of Tc-99m (V) DMSA scans was superior to Tc-99m citrate, which showed faint uptake. Tc-99m (V) DMSA may be a better alternative to Ga-67 citrate in the assessment of the activity and extent of tuberculosis.