Showing papers in "European Journal of Nuclear Medicine and Molecular Imaging in 1984"
TL;DR: This agent or a derivatized form of 99mTc-PnAO may be useful in assessment of regional cerebral blood flow in humans and will passively penetrate biological membranes including the intact blood-brain barrier (BBB) as evidenced by the high brain uptake observed shortly after IV injection.
Abstract: Propylene amine oxime (PnAO) forms a neutral lipid soluble complex with 99mTc. 99mTc-PnAO can be prepared by simple reduction of 99mTc-pertechnetate with stannous ion in the presence of excess PnAO in saline at or near neutral pH. This agent will passively penetrate biological membranes including the intact blood-brain barrier (BBB) as evidenced by the high brain uptake observed shortly after IV injection. The first-pass extraction efficiency in baboons was estimated to be 80% at normal blood flow. This agent or a derivatized form of 99mTc-PnAO may be useful in assessment of regional cerebral blood flow (rCBF) in humans.
92 citations
TL;DR: A comparative study of tumor detection with ten 11C-labeled amino acids including four newly synthesized amino acids was carried out to find the most valuable 11Clabeled Amino acid for the diagnosis of cancer using positron emission tomography.
Abstract: A comparative study of tumor detection with ten 11C-labeled amino acids including four newly synthesized amino acids was carried out to find the most valuable 11C-labeled amino acid for the diagnosis of cancer. 11C-l-methionine showed the highest uptake by the experimental rat hepatoma AH109A (2.7% administered dose/g at 20 min, tumor to blood ratio; 11.4). The second highest uptake was of 11C-aminocyclopentane-carboxylic acid (ACPC). The newly synthesized 11C-dl-methyl-ACPC characteristically showed higher accumulation in tumor than in liver and the tumor to liver ratio reached 3.0 at 60 min after injection. It is suggested that 11C-l-methionine and 11C-dl-methyl-ACPC are useful amino acids for the diagnosis of cancer using positron emission tomography.
78 citations
TL;DR: The studies show the feasibility of using specific antibody to lower the blood background just minutes prior to tumor imaging procedures using radiolabeled proteins.
Abstract: A major problem that arises when radiolabeled serum proteins are used for tumor imaging is the presence of a large amount of circulating background activity that persists for several days This delays imaging for at least 2 days following injection and necessitates computer subtraction of simulated background (second radiopharmaceutical injection) which introduces artifacts that are difficult to control We propose here the injection of specific antibody immediately before imaging as an alternate way of reducing blood background through clearance of the immune complex by the liver
111In-alkyl human transferrin and IgG were injected IV in BALB/c tumor mice, and followed in 18 h by anti-human transferrin and anti-human IgG antibody IV Two hours later, the tumor and organ distribution of activity was compared with control mice not receiving antibody 111In-transferrin blood activity was reduced to 1/48 of control with no decrease in tumor concentration: as a result, the tumor to blood ratio increased from 14:1 to 78:1 111In-IgG blood activity was reduced to 1/17 of control, again with no decrease in tumor The tumor to blood ratios increased from 07:1 to 17:1 The liver picked up most of the blood activity with none of the complex going to spleen, bone marrow, or kidney Dog experiments showed clearance of blood was 90% complete in less than 15 min following antibody injection Simultaneous scintillation images showed complete clearance of activity from the heart and great vessels in the chest and neck, and over the abdomen, with a concomitant increase in liver activity but no increase in spleen, kidney, or bone marrow activity These studies show the feasibility of using specific antibody to lower the blood background just minutes prior to tumor imaging procedures using radiolabeled proteins
75 citations
TL;DR: Segmental analysis of stress ECT yielded as high sensitivity and specificity in the diagnosis of CAD as the planar imaging, which can improve sensitivity in identifying individual vessels involved in deep myocardial regions, especially in those with multivessel disease.
Abstract: The value of stress thallium 201 myocardial emission computed tomography (ECT) in the assessment of coronary artery disease (CAD) was analyzed in 75 patients admitted for coronary arteriography. The ECT provided contiguous transaxial, short-axis, and long-axis sections of the myocardium and the myocardial images were divided into nine segments. The sensitivity and specificity in the diagnosis of CAD were 95% and 93%, respectively. Using selected segments, the ECT identified 97 of 111 (83%) major vessels involved: 89% for right coronary artery (RCA), 88% for left anterior descending (LAD), and 70% for left circumflex (LCx). Among the 75 cases, 35 underwent stress conventional planar imaging within 3 months. The planar imaging provided high sensitivity (90%) and specificity (100%) for the detection of CAD patients as well, but it showed lower sensitivity (57%, P<0.001) in identifying individual vessels involved: 55% for RCA (P<0.01), 70% for LAD, and 36% for LCx (P<0.05). Stress ECT detected vessel involvement more in two-vessel disease (85%) and three-vessel disease (78%) than the planar imaging (50%: P<0.05 and 44%: P<0.01, respectively). Thus, segmental analysis of stress ECT yielded as high sensitivity and specificity in the diagnosis of CAD as the planar imaging. This can improve sensitivity in identifying individual vessels involved in deep myocardial regions, especially in those with multivessel disease.
59 citations
TL;DR: A simple technique of autologous platelet labelling is described, which allows labelling within 40 min, and has the advantage of low costs, as no laminar air flow is required.
Abstract: A simple technique of autologous platelet labelling is described, which allows labelling within 40 min, and has the advantage of low costs, as no laminar air flow is required. Blood (16 ml) was withdrawn into 4 ml ACD, 500 ng prostacyclin was added. After 10 min sedimentation the vials were centrifuged for 5 min at 150 g. The plateletrich plasma in the supernatant was centrifuged at 500 g for 10 min to obtain a platelet pellet. The platelet-poor plasma was preserved in a sterile syringe and the platelet pellet was resuspended in 1 ml tyrode buffer. The cell suspension was labelled at 37° C for 5 min with 100 μCi 111In-oxine sulphate and reinjected after dilution with the plasma. Mean labelling efficiency was 90%±3%, mean recovery 2 h after reinjection 76%±3% (mean±SD).
58 citations
TL;DR: It was found that for the different radiopharmaceuticals, the effective dose equivalent per activity unit administered extends over an interval of five orders of magnitude, from 0.00015 to 20 mSv/MBq.
Abstract: The concept of “effective dose equivalent”, which was introduced by the International Commission on Radiological Protection (ICRP) for occupationally exposed workers, has also created the possibility of expressing by means of a single figure, the radiation risk to patients undergoing different medical radiodiagnostic procedures. In this study, we present the effective dose equivalent for various nuclear-medicine investigations. The figures given are primarily based on a review of data contained in the literature on the mean absorbed dose to various organs. In many cases, however, our own calculations, using biokinetic data derived from the literature, have been used.
44 citations
TL;DR: Data shows that insulin glucose, interfering with fatty acid metabolism, influences the myocardial washout of HDA, and thus support its use as a metabolic tracer.
Abstract: The feasibility of using 123I-heptadecanoic acid (HDA) as a metabolic tracer was studied. Different administration routes of HDA were compared. An intracoronary bolus injection was given to calves (n=3), and an intravenous injection was given to patients (n=4). In addition, we examined the influence of 4-h halothane anesthesia in calves and in patients the impact of an insulin (1.5 IU/kg)+ glucose (1.5 g/kg) infusion on the myocardial kinetics of HDA. Data were accumulated with a scintillation probe in calves (t=50 min) and a gamma camera in patients (t=70 min). In calves after an intracoronary bolus injection of HDA the myocardial time-activity curve could be described by two exponentials. The mean elimination halftime of the initial phase (ta 1/2) was 7.3 min and that of the second phase (tb 1/2) was 35 min. The ratio of the size of the initial and second component at to was 0.93. Halothane anesthesia prolonged the elimination half-times and reduced the component ratio. The biphasic behavior of the myocardial time-activity curve was maintained in patients after intravenous administration of HDA under basal conditions (initial ta 1/2=8.4 min). However, during infusion of insulin+glucose the decline in the myocardial activity was prolonged and monoexponential. This data shows that insulin glucose, interfering with fatty acid metabolism, influences the myocardial washout of HDA, and thus support its use as a metabolic tracer.
39 citations
TL;DR: Results indicate that autologous leucocytes can be efficiently labelled with 99mTc-stannous colloid with good residual cell function and shown in vitro to be viable and maintain normal bactericidal and chemotactic capacity.
Abstract: Autologous leucocytes were labelled in whole blood by phagocytic uptake of 99mTc-stannous colloid. This colloid has a mean particle size of 1.5 μm and labels leucocytes with 81% efficiency. Individual cell uptakes were: granulocytes 42%, monocytes 39%. Isotonic sodium citrate added after the labelling procedure did solubilise excess colloid but was not necessary for adequate removal of excess colloid. Labelled leucocytes were shown in vitro to be viable and maintain normal bactericidal and chemotactic capacity. Biodistribution, clearance rates and dosimetry are presented. These results indicate that autologous leucocytes can be efficiently labelled with 99mTc-stannous colloid with good residual cell function.
39 citations
TL;DR: The authors' results explain the high uptakes in the kidney and liver in biodistribution studies of the 18F-labeled pyrimidines.
Abstract: 18F-labeled 5-fluorouracil(FUra), 5-fluoro-2′-deoxyuridine(FdUrd), and 5-fluorouridine(FUrd) were synthesized with high radiochemical purities. The 18F-labeled pyrimidines were injected into rats. The metabolites in serum, bile, and urine were analyzed up to 2 h after administration by radio-high performance liquid chromatography(HPLC). The blood clearance of three pyrimidines was very rapid. In the serum the nucleosides and base disappeared very rapidly with a biological half-life of about 2 min and most of them had disappeared by 60 min. The metabolites in the urine were similar to those in the serum. In the bile pyrimidine nucleosides and base were not detected. 18F was found in the metabolites. Our results explain the high uptakes in the kidney and liver in biodistribution studies of the 18F-labeled pyrimidines.
37 citations
TL;DR: A patient with well-differentiated thyroid carcinoma had a whole body scan using 5 mCi 131I which demonstrated abnormal uptake of 131I in a palpable pelvic mass which was consistent with serous cystadenoma of the ovary.
Abstract: A patient with well-differentiated thyroid carcinoma had a whole body scan using 5 mCi 131I which demonstrated abnormal uptake of 131I in a palpable pelvic mass Approximately 24 years ago the patient had a total thyroidectomy followed by 131I treatment The histologic examination of the mass was consistent with serous cystadenoma of the ovary No thyroid tissue or teratoma was identified The mechanism for the unusual uptake of 131I in a benign ovarian tumor is not clear, and the differential diagnosis of metastatic thyroid cancer is briefly reviewed
34 citations
TL;DR: It is suggested that pretreatment with carbimazole reduces the degree of radiation induced thyroid damage.
Abstract: Of a group of 55 thyrotoxic patients given therapeutic radio-iodine (131I), 24 were made euthyroid with carbimazole before131I: the remainder were given131I alone. Carbimazole was discontinued 5 days before131I was administered. By 3 months after131I treatment there was a greater incidence of hypothyroidism in the group given131I alone (42% vs 25%), but a lower incidence of persistent thyrotoxicosis (16% vs 46%), (P>0.05). One year after treatment a similar proportion of each group had persistent thyrotoxicosis (21% vs 23%), but there remained a lower incidence of hypothyroidism in the group pretreated with carbimazole (25% vs 45%). It is suggested that pretreatment with carbimazole reduces the degree of radiation induced thyroid damage.
TL;DR: In this paper, the authors used perfusion scintigraphy of the legs to define intermittent claudication quantitatively, based on Sapirstein's indicator fractionation principle.
Abstract: 201Tl perfusion scintigraphy of the legs was evaluated to define intermittent claudication quantitatively, based on Sapirstein's indicator fractionation principle. After intravenous injection of 201Tl with or without exercise, the distribution of the radiotracer throughout the body was obtained using the whole blood scanner. Regional blood flow of cardiac output for three segments of the leg was estimated as a regional fractional uptake (rFU) distributed in these segments compared with the whole body distribution. The validity of the principle was confirmed by a comparative study with 99mTc-MAA (r = 0.979). Normal rFUs (%) for each section at rest and after stress, respectively, were 5.49 +/- 0.69 and 19.40 +/- 2.04 (whole leg); 3.57 +/- 0.49 and 12.26 +/- 1.91 (thigh); 1.59 +/- 0.34 and 6.58 +/- 0.61 (calf). The rates of rFU change from the state of rest to stress (delta rFU) in normals were 3.41 +/- 0.45 (whole leg), 3.44 +/- 0.61 (thigh), and 4.30 +/- 1.03 (calf). Although rFU was within normal limits in patients with arteriosclerosis obliterans (ASO) and thromboangitis obliterans (TAO), delta rFU of the whole leg was significantly decreased from the normal value of 3.41 +/- 0.45 to 1.95 +/- 0.40 for ASO (P less than 0.001) and 1.82 +/- 0.47 for TAO (P less than 0.001). A defect or decreased activity on the stress scintigraph was well correlated with the angiographic findings.
TL;DR: A case of systemic AL (amyloid light-chain-derived) amyloidosis is presented, in which a 99mTc-diphosphonate bone scan demonstrated the intense uptake of tracer in the liver, spleen, heart, thyroid, oropharyngeal region, intestinal tract and uterus.
Abstract: A case of systemic AL (amyloid light-chain-derived) amyloidosis is presented, in which a 99mTc-diphosphonate bone scan demonstrated the intense uptake of tracer in the liver, spleen, heart, thyroid, oropharyngeal region, intestinal tract and uterus. The presence of amyloid deposits in these organs was confirmed at autopsy. A review of the literature is given. In amyloidosis, the binding of radionuclide-labeled calcium-seeking agents, such as diphosphonate and pyrophosphate, may be explained by the high calcium content of amyloid. The presence of calcium in amyloid is due to the presence of the non-fibrillar protein, amyloid P-component (AP). In our patient, the amyloid deposits reacted on immunofluorescence with antibodies directed against AP.
TL;DR: Cardiac scintigraphy was performed in six patients with a documented previous myocardial infarction, in one patient with mitral regurgitation, and in four healthy volunteers following administration of 99mTc-tris-DMPE.
Abstract: Cardiac scintigraphy was performed in six patients with a documented previous myocardial infarction, in one patient with mitral regurgitation, and in four healthy volunteers following administration of 99mTc-tris-DMPE. An intense early blood pool phase permitted gated blood pool scintigraphy and left ventricular ejection fraction calculation. A myocardial phase 12–14 h later permitted myocardial perfusion imaging. The rest myocardial perfusion image quality with 99mTc-tris-DMPE appeared to be superior to the resting image quality obtained with 99mTc-dichloro-DMPE but was inferior to the resting image quality obtained with 201Tl.
TL;DR: 99mTc-Ap is an excellent agent for renal imaging and seems promising for renal function studies, especially in patients with far advanced renal failure.
Abstract: Aprotinin (Ap), a low-molecular-weight polypeptide (6500 dalton), is a protease inhibitor which is electively and stably accumulated in the kidney. In 112 adult patients, with either uni- or bilateral renal disease with different degrees of renal impairment (from normal GFR to advanced renal failure), renal scans were performed by means of Ap labelled with99mTc. Highly satisfactory renal scans were obtained in all patients. In 20 patients with renal failure (serum creatinine 1.8–8.5 mg/dl, mean 4.7) a comparison was made of the renal scans obtained with99mTc-Ap and with99mTc-DMSA.99mTc-Ap was slightly better than99mTc-DMSA, especially in patients with far advanced renal failure.
TL;DR: The reproducibility of the technique is quite good, its capacity to detect minor esophageal transit disorders is demonstrated, and its principal advantage is its ultra-short half-life.
Abstract: A method for quantifying esophageal transit by means of 81mKr is described. The principal advantage of 81mKr compared with 99mTc is its ultra-short half-life with its consequences on radiation dose and counting statistics. Factors which may influence the esophageal transit time such as body posture, volume of the tracer, and the nature of the tracer were studied. The reproducibility of the technique is quite good and its capacity to detect minor esophageal transit disorders is demonstrated.
TL;DR: The renal handling of99mTc-DMSA seems to be an indicator of proximal tubular function and the relative β2-microglobulin clearance was found to be a clear distinction between patients with proximal Tubulopathy and control patients.
Abstract: The clearance of125I-sodium iothalamate,131I-sodium hippurate,99mTc-DMSA, and β2-microglobulin were determined in 20 patients with proven or suspected proximal tubular dysfunction and in 18 control patients with various renal diseases. A clear distinction in the relative99mTc-DMSA clearance was observed between patients with proximal tubulopathy (14%–35%) and control patients (>14%). A similar difference between the two groups was found in the relative β2-microglobulin clearance. Nine patients with proximal tubulopathy showed an elevated filtration fraction versus only two control patients. The renal handling of99mTc-DMSA seems to be an indicator of proximal tubular function.
TL;DR: This investigation concludes that the observed lymph flow directions in patients injected peritumorally are of value for the follow-up and Quantitative lymphoscintigraphy in patients with melanoma of the lower extremities is of no value for excluding ilio-inguinal lymph node metastases.
Abstract: Lymphoscintigraphy using 99mTcSb2S3 colloid was performed in 32 patients with malignant melanoma. Subcutaneous injections were made peritumorally in 20 patients and dorsopedally in 12 patients. Regional lymph node dissections were carried out on the following day in 16 patients and the resected lymph nodes were weighed, measured for radioactivity, and examined by light microscopy.
TL;DR: An absolute quantitation of regional extravascular lung water is possible after absorption correction of the PET data via transmission measurements and calibration of the camera system and the values agree also with gravimetric lung water determinations.
Abstract: Continuous infusion of 15O-labeled water allows a quantitative measurement of the total water pool in the chest region by positron emission tomography (PET). By subsequent inhalation of 11CO the intravascular space (blood pool) can be quantitated as well. After a suitable normalization of the intravascular activities the extravascular water can be determined by subtraction of the blood pool from the water pool. The regional extravascular lung water distribution can be visualized in tomographic slices. The method was validated in an animal experiment using five dogs. They were measured before and after induction of a lung edema by IV injection of oleic acid. The increase of extravascular lung water was monitored by the thermodye-dilution method (TDD). The correlation of extravascular lung water as measured by TDD with PET measurements is good (r=0.94). The PET values agree also with gravimetric lung water determinations. An absolute quantitation of regional extravascular lung water is possible after absorption correction of the PET data via transmission measurements and calibration of the camera system. The uncertainty in the absolute quantification is±20%. In the experiments described here the mean extravascular lung water was 0.13 g/cm3 before and 0.25 g/cm3 after induction of lung edema.
TL;DR: Using the depth-response of a rCBF detector in combination with a computer model of the human brain, it was possible to calculate the signal contributions from different regions in the brain and showed that large errors may be introduced in the calculation of regional gray matter blood flow when flow assymetries exist.
Abstract: In bilateral regional cerebral blood flow measurements with xenon 133, Compton scatter and hemispheric cross talk obscure the regional resolution and increase the uncertainty of the results. In order to evaluate the effects of these extraregional signal sources on the calculation of regional gray matter blood flow, a computerized simulation procedure was developed. Using the depth-response of a rCBF detector in combination with a computer model of the human brain, it was possible to calculate the signal contributions from different regions in the brain. The results obtained show that large errors may be introduced in the calculation of regional gray matter blood flow when flow assymetries exist.
TL;DR: The pubis/sacrum uptake ratio obtained by the use of scan techniques appears to be a useful parameter for following the evolution of the pain.
Abstract: We studied 32 cases of pubic pain in sportsmen and compared the radiographic and scintigraphic findings. Six case histories are presented in detail. The pubis/sacrum uptake ratio obtained by the use of scan techniques appears to be a useful parameter for following the evolution of the pain.
TL;DR: A 39-year-old woman was admitted to hospital with headaches, vomiting, psychic impairment and diplopia, and at operation, two brain cysts were totally extirpated without rupture.
Abstract: A 39-year-old woman was admitted to hospital with headaches, vomiting, psychic impairment and diplopia. Three hydatid cysts of the lung had been previously removed. An avascular mass in the left hemisphere with left-to-righ displacement of the anterior cerebral arteries was noted during a brain angioscintigraphy. A computed tomography (CT) brain scan showed two cystic lesions situated in the left-frontal and occipital regions. A CT abdominal scan showed multiple cysts in the liver, spleen and both kidneys. At operation, two brain cysts were totally extirpated without rupture. The definite pathological diagnosis was secondary hydatid cysts. The headaches, vomiting and diplopia were persistent in the post-operative period. Seven days after the operation, a CT brain scan showed an infratenrorial cyst. The patient rejected any surgical intervention.
TL;DR: An improved method for parathyroid scanning using thallium-201 and technetium-99m subtraction imaging is described, which successfully localised ten of eleven parathy thyroid adenomas confirmed at neck exploration and was negative in a single patient with recurrent, functionalParathyroid carcinoma.
Abstract: An improved method for parathyroid scanning using thallium-201 and technetium-99m subtraction imaging is described. The technique successfully localised ten of eleven parathyroid adenomas confirmed at neck exploration. Two false-positive studies were encountered in patients with no adenoma at operation, probably due to thyroid nodules. The technique was less successful in identifying diffusely hyperplastic parathyroid glands and was negative in a single patient with recurrent, functional parathyroid carcinoma.
TL;DR: This study clearly shows that PPT can be detected in vivo with an easy, noninvasive scintillation camera method.
Abstract: It has been reorted in earlier in vitro studies that soft tissue trauma and endotoxin-induced shock causes pulmonary platelet trapping (PPT). This paper describes a noninvasive in vivo technique for dynamic studies of PPT in rabbits. Autologous platelets were labeled with111In and reinfused into the animals. The following day, the rabbits were anesthetized and placed in a supine position under a scintillation camera. Continuous measurement of the activity distribution in the animal was performed for 35 min. The first 5 min represented a preshock measurement, whereafter endotoxinE. coli was injected IV. The following 2–3 min showed a sudden increase of radioactivity in the lungs indicating PPT, and thereafter a slow decrease to almost the preshock level. A simultaneous decrease in the number of platelets and the radioactivity in peripheral blood also indicated the induction of PPT. This study clearly shows that PPT can be detected in vivo with an easy, noninvasive scintillation camera method.
TL;DR: In 42 patients with untreated Paget's disease there was a linear relationship between the visually assessed score and the logarithm of the computermeasured ratio, and in 27 patients treated with APD a decrease in uptake was measured in all lesions.
Abstract: Two methods of evaluating bone scintigrams in Paget's disease of bone were compared. Bone scintigraphy was performed after IV injection of 20 mCi 99mTc-Sn-EHDP. Qualitative evaluation was carried out by visual assessment of the photographs of the oscilloscope of the gamma camera, using a scale of six well-defined scores. Quantitative evaluation of uptake of radionuclide was obtained by calculating the ratio of the number of counts per pixel in pagetoid bone with that in comparable normal bone; measurements were performed by a computer interfaced to the gamma camera, after marking the regions of interest with a light-pen. In 42 patients with untreated Paget's disease there was a linear relationship between the visually assessed score and the logarithm of the computer-measured ratio. In 27 patients treated with APD a decrease in uptake was measured in all lesions and was usually also detected visually; however, in 14% of these lesions the changes (ranging from 9% to 70%) were not visible to the eye. Here too, visual estimation of the changes corresponded to the logarithm of the measured changes. In conclusion, there is a semilogarithmic relationship between the visual and the physical methods.
TL;DR: It is shown that in isolated perfused guinea-pig hearts halide diffusion from the mitochondrion to the blood is the rate-determining step of IHA pharmacokinetics in normal myocardium, and in normal hearts a single phase iodide elimination half-time was observed.
Abstract: Long-chain ω-halofatty acids, especially ω-123I-iodoheptadecanoic acid (IHA), are widely used clinically as radiopharmaceuticals for functional heart imaging. The metabolic interpretation of the various elimination rates, however, remains in dispute. It has been previously shown (Kloster and Stocklin 1982) that in isolated perfused guinea-pig hearts halide diffusion from the mitochondrion to the blood is the rate-determining step of IHA pharmacokinetics in normal myocardium. We have now extended these in vitro experiments to normal and globally ischaemic isolated perfused rabbit hearts. Again, in normal hearts a single phase iodide elimination half-time (14.3±2.1 min) was observed. In hearts made globally ischaemic for 90 min, the iodide elimination was biphasic with a first fast phase (T1/2=3.8±0.49 min) and a late slow phase (T1/2=60.5±14.0 min). The first fast phase is attributed to iodide ion released by residual β-oxidation (more rapid than in normal hearts due to damaged membranes in ischaemia), while the late slow phase is explained by β-oxidation of IHA slowly released by hydrolysis of intracellular lipid stores. These data were compared with published data from investigations in patients which seem to support our interpretation.
TL;DR: Autoradiographic and pharmacologic studies performed in mice and dogs receiving radioiodinated mIBG suggest that the m IBG and catecholamine uptake mechanisms are only partially the same and indicate the high affinity of mibG for adrenal medulla.
Abstract: In order to investigate the mechanism of uptake of meta-iodobenzylguanidine (mIBG) by the adrenal glands, autoradiographic and pharmacologic studies were performed in mice and dogs receiving radioiodinated mIBG.
TL;DR: The ejection fraction of RV was found to be significantly decreased in patients with RVAMI compared with the other group, and the clinical and prognostic importance of the early diagnosis of RVAMI is stressed.
Abstract: Studies of pathology have shown that involvement of the right ventricle (RV) in acute myocardial infarction (AMI) is relatively common. Our experience in the noninvasive diagnosis of RVAMI and its early prognosis is presented. Sixty patients with AMI were prospectively studied: 40 patients with inferior AMI and 20 patients with anterior AMI. The evaluation was made by: (1) Clinical findings: hypotension, congestive heart failure, sinus bradycardia>40/min, dysrhythmia, and conduction disturbances; (2) ECG record including precordial lead (V4R); (3) Radioisotope heart scintigraphy:99mTc-PYP infarct scintigraphy and multigated acquisition MUGA blood pool scanning. Of the 40 patients diagnosed as having inferior AMI, 20 cases (50%) were found to be associated with RVAMI. All of them were diagnosed by positive radionuclide studies, and 17 (85%) also demonstrated a ST segment elevation of 01. mV, and pathological Q waves in the V4R lead. The ejection fraction (EF) of RV was found to be significantly decreased in patients with RVAMI compared with the other group (mean, 27% versus 57%). Among the 20 patients with RVAMI, 16 (80%) showed various complications during the hospitalization period, versus 9 patients (45%) from the group with inferior AMI. The most common complication in RVAMI patients was conduction disturbances (7 of 20 versus 2 of 20 patients).
TL;DR: In 106 kidneys including solitary and pathological kidneys, individual renal volume correlated well with individual DMSA renal uptake rate which demonstrates cortical functioning mass, depending on the cortical blood flow.
Abstract: The in vivo renal volume was determined using SPECT for 99mTc-DMSA renal imaging The total renal volume was derived by summing the DMSA distribution volumes of the transaxial slices in the whole kidney In 20 healthy subjects the renal volume in the right kidney was 220 ml for men and 1952 ml for women, while that in the left kidney was 213 ml for men and 1937 ml for women Differences in those values were not statistically significant A good correlation was found between renal volumes in both kidneys and body surface area In 106 kidneys including solitary and pathological kidneys, individual renal volume correlated well with individual DMSA renal uptake rate which demonstrates cortical functioning mass, depending on the cortical blood flow Thus, SPECT enables an accurate noninvasive means of estimating in vivo functioning renal volume
TL;DR: Using ERPFs estimated from compartment analysis of the entire 60-min plasma disappearance curve, this work has compared the errors of data calculated from use of eight SI methods made at various times along the disappearance curve with that from the optimum SS curve.
Abstract: Numerous simplified methods for the estimation of ERPF have been described, including the so-called slope/intercept (SI) methods, based on the analysis of the slope of certain segments of the131I-OIH plasma disappearance curve and its y-axis intercept, and the single sample (SS) clearance method, based on theoretical volumes of OIH distribution at some fixed time after injection. Using ERPFs estimated from compartment analysis of the entire 60-min plasma disappearance curve, we have compared the errors of data calculated from use of eight SI methods made at various times along the disappearance curve with that from the optimum SS curve. The errors obtained from the SS method were approximately 50% less than those obtained from the SI methods. The errors of the SI methods are greater at both ends of the 60-min plasma curve than when samples are drawn near the mid-time. The SS method appears to be the method of choice for the estimation of ERPF using single injection techniques.