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PubMed2002

Dynamic variations of local cerebral blood flow in maximal electroshock seizures in the rat.

PURPOSE: Measurement of cerebral blood flow is routinely used to locate the areas involved in generation and spread of seizures in epilepsy patients. Because the nature of the hyperperfused regions varies with the timing of injection of tracer, in this study, we used a rat model of maximal electroshock seizures to follow up the time-dependent changes in the distribution of seizure-induced cerebral blood flow (CBF) changes. METHODS: CBF was measured by the quantitative autoradiographic [14C]iodoantipyrine technique over a 30-s duration. The tracer was injected either at 15 s before seizure induction, simultaneous with the application of the electroshock (tonic phase), at the onset of the clonic phase, or at 3 and 6 min after the seizure (postictal phase). RESULTS: Rates of CBF underwent dynamic changes during the different phases of seizure activity and largely increased over control levels (< or =400%) in the 45 regions studied during all phases of the seizure (first 3 times). CBF remained higher than control levels in 35 and 15 areas at 3 and 6 min after the seizure, respectively. CONCLUSIONS: The distribution of maximal CBF increases showed a good correlation with their known involvement in the circuits underlying the clinical expression of the different types of seizure activity, tonic versus clonic.

Animals↗
PubMed2006

Evaluation of transcriptional activity of the oestrogen receptor with sodium iodide symporter as an imaging reporter gene.

BACKGROUND: Oestrogen receptors are ligand-dependent transcription factors whose activity is modulated either by oestrogens or by an alternative signalling pathway. Oestrogen receptors interact via a specific DNA-binding domain, the oestrogen responsive element (ERE), in the promoter region of sensitive genes. This binding leads to an initiation of gene expression and hormonal effects. OBJECTIVE: To determine the transcriptional activity of the oestrogen receptor, we developed a molecular imaging system using sodium iodide symporter (NIS) as a reporter gene. METHODS: The NIS reporter gene was placed under the control of an artificial ERE derived from pERE-TA-SEAP and named as pERE-NIS. pERE-NIS was transferred to MCF-7, human breast cancer cells, which highly expressed oestrogen receptor-alpha with lipofectamine. Stably expressing cells were generated by selection with G418 for 14 days. After treatment of 17beta-oestradiol and tamoxifen with serial doses, the (125)I uptake was measured for the determination of NIS expression. The inhibition of NIS activity was performed with 50 micromol x l(-1) potassium perchlorate. RESULTS: The MCF7/pERE-NIS treated with 17beta-oestradiol accumulated (125)I up to 70-80% higher than did non-treated cells. NIS expression was increased according to increasing doses of 17beta-oestradiol. MCF7/pERE-NIS treated with tamoxifen also accumulated (125)I up to 50% higher than did non-treated cells. Potassium perchlorate completely inhibited (125)I uptake. When MDA-MB231 cells, the oestrogen receptor-negative breast cancer cells, were transfected with pERE-NIS, (125)I uptake of MDA-MB-231/pERE-NIS did not increase. CONCLUSION: This pERE-NIS reporter system is sufficiently sensitive for monitoring transcriptional activity of the oestrogen receptor. Therefore, cis-enhancer reporter systems with ERE will be applicable to the development of a novel selective oestrogen receptor modulator with low toxicity and high efficacy.

Breast Neoplasms↗
PubMed2005

Gamma scintigraphic evaluation of a miniaturized AERx pulmonary delivery system for aerosol delivery to anesthetized animals using a positive pressure ventilation system.

The purpose of this study was to characterize performance of a miniaturized AERx((R)) Pulmonary Delivery System designed for aerosol administration to large animal models. The miniaturized AERx System was developed through a systematic scaling down of the AERx System used for humans to allow for operation in certain animal models with lower inspiratory flow rates and inhaled volumes than those used for humans. We used gamma scintigraphy to characterize the in vivo particle deposition achieved with the miniaturized AERx System in two dogs. The dogs were 3-4 years old, and weighed 10.4 kg and 13.6 kg. Acepromazine was used as pre-anesthetic medication. Anesthesia was induced with 5% isoflurane. The trachea was intubated using an endotracheal tube (internal diameter 8.5 mm), and the dogs were ventilated using positive pressure during the exposure using the LRRI puff generator. An inhalation of aerosol was initiated by activation of the puff generator though the computer-controlled interface. Each dog inhaled approximately 0.8 L per puff, of which the aerosol volume comprised approximately 0.25 L, at a target flow rate of 15 L/min. The dogs were exposed to 10 AERx Strips in 10 puffs. The mass median aerodynamic diameter of the aerosolized formulation was approximately 1.25 microm with a fine particle fraction <3.5 microm of 0.976. The scintigraphic images showed uniform bilateral lung deposition following aerosol delivery with the AERx System. Total lung deposition for the two dogs was 10.7% and 18% of the loaded dose from the AERx Strip. The corresponding peripheral lung: inner lung (P/I) ratios were 0.83 and 0.75, suggestive of deposition in the deep lung. Only 0.1% to 0.2% of the loaded dose was exhaled. These results show the miniature AERx System can efficiently deliver aerosols to the deep lung of dogs. The miniaturized AERx System would be a valuable tool for conducting proof-of-concept studies as well as safety and tolerability analysis of inhaled drug candidates in large animal models.

Administration, Inhalation↗
PubMedDate not supplied

[The use of a new analogue DGlu-Octagastrin in scintigraphy of medullary thyroid carcinoma].

INTRODUCTION: Medullary thyroid carcinomas (MTC) reveal overexpression of several peptide receptors particularly of gastrin and cholecystokinin 2 (CCK2). Experimental studies of various CCK-2/gastrin analogues found that a C-terminal, 8-aminoacid peptide, (D)Glu-octagastrin, has optimal properties. Thus, the aim of our studies was to prepare (99m)Tc-labelled HYNIC-octagastrin, to evaluate its biologic tolerance in animals and introduce for scintigraphy in patients with MTC. MATERIAL AND METHODS: HYNIC-(D)Glu-octagastrin was from piCHEM (Graz, Austria), (99m)Tc generator from Amersham (Health), other reagents were purchased from Sigma. Labelling of the peptide was performed in phosphate buffer of pH 6.0 for 10 minutes at 100(o)C using EDDA and tricine as coligands. RESULTS: The labeling yields were high (above 95%); the specific activity amounted to 1200 to 1430 microCi/microg. Radiochemical purity on SepPak cartridge and ITLC ranged from 94 to 98%. No adverse effects were observed in mice after administration of 10 to 50 times greater doses that those used in patients. Clinical studies comprised 20 patients with MTC and high serum calcitonin. (99m)Tc-EDDA/HYNIC-(D)Glu-octagastrin, 500 to 700 MBq, was administered iv and whole body scintigraphy was performed using a double head gamma-camera (Varicam, Elscint) 2 and 4 hours later. Increased accumulation of the tracer in foci of MTC and its metastases was found in 8 patients. CONCLUSIONS: Scintigraphy with a new gastrin analogue ((D)Glu-octagastrin) makes it possible to detect MTC with overexpression of CCK-2/gastrin receptors and to select patients for receptor-mediated radiopeptide therapy using DOTA-gastrin analogues labelled with (177)Lu and (90)Y.

Animals↗
PubMed1990

Generation and characterization of human monoclonal antibody HMD4 against ovarian carcinoma and the study of radioimmunoimaging in nude mice.

Lymphocytes from regional lymph nodes of patients with ovarian carcinoma were immortalized by fusing them with a nonsecreting cell line of murine myeloma (Sp2/0-Ag14). By early cloning and recloning a hybrid cell line, named HMD4, was established. It has secreted human IgG for more than 15 months stably. Chromosome analysis corresponded with the characterization of human-mouse hybridoma. Large quantities of ascites were obtained after hybrid cells injection into the primed nude mice. Human IgG of light chain was detected and purified from the ascites. Twenty-six of 43 (60.5%) epithelial ovarian cancers were positively stained with HMD4 by ABC immunoperoxidase methods while nonepithelial ovarian cancers and almost all benign tumors and normal tissues were negative. The molecular weight of the antigen recognized by HMD4 was 55KDa determined by Western blotting. 131I labeled HMD4 was administered intraperitoneally to nude mice bearing human ovarian epithelial adenocarcinoma; 131I labeled normal human IgG and normal murine IgG were used as controls. Measurements of T/NT and T/B ratios of 131I-HMD4 were done. Radioimaging showed HMD4 clearly localized on tumor regions at 48 and 72 hours and the biodistribution and metabolism of the labeled HMD4 corresponded with the images. The above results indicate that HMD4 was specific to ovarian carcinoma, a hopeful clue for clinical applications.

Animals↗
PubMed1986

The (F)utility of the thallium-201 quantitative lung/myocardial ratio in the detection of coronary artery disease.

Exercise-induced increases in pulmonary uptake of thallium-201 (201Tl) have been associated with exercise-induced myocardial dysfunction. To evaluate this phenomenon more replicably, a quantitative semi-automated computer program was used to generate, from anterior exercise and delayed views, lung-myocardial ratios (LMR) of 201Tl uptake in 78 patients [40 normal, 38 with coronary artery disease (CAD)]. Patients with CAD had a significantly higher mean exercise lung myocardial ratio (EXLMR) than normals (30.8 vs. 27.3; P less than 0.003). In patients with adequate exercise (greater than or equal to 85% of an age-adjusted maximal heart rate), the EXLMRs of CAD patients were significantly higher than those of normals (29.7 vs. 25.5; P = 0.003). However, this difference between CAD and normal patients was not apparent in a patient subgroup with submaximal exercise levels (less than 85% of an age-adjusted maximal heart rate). In both normal and CAD patients, EXLMR decreased with increasing exercise levels (r = -0.555; P = 0.007). In patients with 201Tl scans lacking visually defined perfusion defects (visually normal), an elevated LMR detected 60% of CAD cases with 81% specificity. A considerably elevated EXLMR in patients achieving adequate exercise should suggest the presence of CAD, even if there are no visually apparent cardiac perfusion defects. With submaximal exercise, however, the EXLMR is not a useful discriminator between CAD patients and normals.

Adult↗
PubMed2005

Preparation and evaluation of (68)Ga-DOTA-hEGF for visualization of EGFR expression in malignant tumors.

UNLABELLED: Detection of epidermal growth factor receptor (EGFR) overexpression in many carcinomas provides important diagnostic information, which can influence patient management. The use of PET may enable such detection in vivo by a noninvasive procedure with high sensitivity. The aim of this study was to develop a method for preparation of a positron-emitting tracer based on a natural ligand to EGFR, the recombinant human epidermal growth factor (hEGF), and to perform a preclinical evaluation of the tracer. METHODS: DOTA-hEGF (DOTA is 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid) was prepared by coupling of a N-sulfosuccinimide ester of DOTA to hEGF. The conjugate was labeled with a generator-produced positron-emitting nuclide, (68)Ga (half-life = 68 min), using microwave heating. Binding specificity, affinity, internalization, and retention of (68)Ga-DOTA-hEGF was studied in 2 EGFR-expressing cell lines, U343 glioma cells and A431 cervical carcinoma cells. Biodistribution and microPET visualization studies were performed in BALB/c nu/nu mice bearing A431 carcinoma xenografts. RESULTS: A 1-min-long microwave-assisted labeling provided radioactivity incorporation of 77% +/- 4%. Both cell lines demonstrated receptor-specific uptake of the conjugate, rapid internalization of the tracer, and good retention of radioactivity. Binding to both cell lines occurred with high affinity, approximately 2 nmol/L. The biodistribution study demonstrated accumulation of radioactivity in xenografts and in EGFR-expressing organs. The microPET imaging study enabled visualization of tumors and demonstrated quick--within 5 min--localization of radioactivity in tumors. CONCLUSION: (68)Ga-DOTA-hEGF has potential for imaging EGFR overexpression in tumors.

Animals↗
PubMed1996

Utility of technetium-99m-DTPA in determining regional ventilation.

UNLABELLED: The goal of this study was to determine the usefulness of radiolabeled aerosols in the assessment of regional ventilation in tracheotomized patients maintained on mechanical ventilation. METHODS: Three commercially available radioaerosol nebulizer kits were studied on the bench to determine nebulizer efficiency and particle distribution of 99mTc-DTPA aerosols. We studied ventilated tracheotomized human subjects with a gamma camera and simultaneously measured regional ventilation with 81mKr gas and 99mTc-DTPA aerosol. Images were compared by analysis of radioactivity distributions in computer-generated regions of interest. RESULTS: The UltraVent nebulizing system produced the smallest particles with a mass median aerodynamic diameter of 0.9 micron compared to the AeroTech I and Venti-Scan II systems, which both produced aerosols of 1.3 microns. Despite relatively small particle sizes, 99mTc-DTPA deposition images with the UltraVent nebulizer did not accurately represent regional ventilation as measured by 81mKr equilibrium. Visual inspection of images revealed significant amounts of particle deposition in the region of the trachea which was diminished but not eliminated following replacement of the tracheotomy tube inner cannula. Based on regional analysis, correlation between radioactivity distributions of both isotopes was poor (r = 0.262, p = 0.162) with segmental analysis suggesting that the upper and middle lung regions were significantly affected by residual tracheal activity. CONCLUSION: The lungs of patients maintained on mechanical ventilation can be imaged after the inhalation of 99mTc-DTPA from commercially available delivery kits, but the correlation between aerosol deposition and regional ventilation is poor. Better definition of ventilated lung segments is obtained when using a gas such as 81mKr because tracheal activity with the radiolabeled gas is minimized.

Adult↗
PubMed2002

Model-based comparison of maternal and foetal organ doses from (99m)Tc pertechnetate, DMSA, DTPA, HDP, MAA and MAG(3) diagnostic intakes during pregnancy.

Organ residence times were calculated for diagnostic intakes of (99m)Tc pertechnetate, 2,3-dimercaptosuccinic acid (DMSA), diethylene triamine penta-acetic acid (DTPA), hydroxymethylene diphosphonate (HDP), macroaggregated albumin (MAA) and mercapto-acetyltriglycine (MAG(3)) during the 1st and 3rd stages of pregnancy and used with the MIRDOSE3 pregnant female phantoms for generation of dose estimates. At stage 3 individual foetal organ doses were estimated via a surrogate phantom based on that for the new-born but with mean dose/cumulated activity ( S) values scaled for compatibility with foetal whole body S. Stage 1 or 3 whole foetus doses ranged from 5.2 to 0.77 microGy MBq(-1) respectively, analogous to current ICRP estimates for these agents using similar in vivo biodistribution model databases. Most stage 3 maternal and foetal organ doses were similar within a factor of 3, being higher in the foetus than the mother with pertechnetate, DTPA and MAG(3), and lower with DMSA, HDP and MAA. Doses were more uniformly distributed among foetal organs than in the mother. Placental transfer was greatest with pertechnetate, where dose to the stage 3 foetal thyroid was 60-140 microGy MBq(-1). With each agent there was more placental transfer in stage 3 than in stage 1, but doses to stage 1 whole foetus were always higher, with the contribution from the mother dominant. For DMSA, HDP and MAG(3) the maternal contribution to total foetal body dose exceeded 93% for both stages.

Animals↗
PubMed1991

Acute and chronic bioeffects of single and multiple doses of piezoelectric shockwaves (EDAP LT.01).

Piezoelectric second generation lithotriptors are an established means of administering extracorporeal shockwave lithotripsy (ESWL) enabling treatment to be performed without anaesthesia or analgesia, but higher shockwave doses and multiple or staged treatment are frequently required. The bioeffects of this modality of ESWL, therefore, require further assessment. Seven experimental groups of adult male rabbits were treated using the EDAP LT.01 in order to determine the acute and chronic bioeffects of clinical dose, excess dose, divided excess dose, high frequency and multiple treatment (X10) piezoelectric shockwaves (PSW). Renal function was measured before and after treatment using mercaptoacetyltriglycine (MAG 3) scans. Gross and histological morphological changes were assessed at one and 30 days following application of PSW. Application of single clinical dose PSW was not associated with any significant functional or morphological renal injury. Excess dose PSW caused transient gross renal contusion, which resolved in the majority of animals with no persistent microscopic abnormality. Divided excess dose PSW resulted in no gross or microscopic damage. High frequency PSW was associated with mild histological abnormality. Multiple PSW treatments caused small discrete fibrotic lesions in all cases, without any change in renal function.

Animals↗
PubMed2005

Examination of dosimetry accuracy as a function of seed detection rate in permanent prostate brachytherapy.

The variation of permanent prostate brachytherapy dosimetry as a function of seed detection rates was investigated for I125 implants with seed activities commonly employed in contemporary practice. Post-implant imaging and radiation dosimetry data from nine patients who underwent PPB served as the basis of this simulation study. One-thousand random configurations of detected seeds were generated for each patient dataset using various seed detection levels from 30% to 99%. Dose parameters, including D90, were computed for each configuration and compared with the actual dosimetry data. A total of 108 000 complete sets of post-PPB dose volume statistics were computed. The results demonstrated that although the average D90 differed from the true value by less than 5% when 70% or more seeds were identified, the D90 of an individual case could deviate up to 13%. The 95% confidence interval (CI) of estimated D90 values differ by less than 5% from the actual value when 95% or more seeds are detected, or approximately a 7 Gy difference in the D90 value for a prescription dose of 144 Gy. Estimated target volume dose parameters tended to decrease with reduced seed detection rates. The most variable dose parameter was the prostate V100 in absolute scale while the urethral V100 was most variable in a relative sense. Based on this comprehensive simulation study, it is suggested that 95% or more seeds need to be localized in order to provide an accurate estimation of dose parameters for contemporary iodine 125 permanent prostate brachytherapy.

Brachytherapy↗
PubMed1986

Regional comparison of technetium-99m DTPA aerosol and radioactive gas ventilation (xenon and krypton) studies in patients with suspected pulmonary embolism.

The regional distribution of [99mTc]DTPA aerosol was compared with that of 133Xe (n = 30) and krypton (n = 24) in a group of patients with suspected pulmonary embolism. All patients had an aerosol study using a recently available commercial generator system, a ventilation study with one of the gases, and perfusion imaging. Regional information was assessed visually on xenon, krypton, and aerosol studies independently by considering each lung as three equal-sized zones. In addition, gas ventilation findings peripheral to regions of aerosol turbulence ("hot spots") were evaluated. Only 64% of the zones were in complete agreement on xenon and aerosol. Most of the discordance between xenon and aerosol was accounted for by minor degrees of 133Xe washout retention in zones that appeared normal in the aerosol study. An agreement rate of 85% was noted between 81mKr and aerosol regionally. The regions of discordance between aerosol and gas studies, however, usually were associated with unimpressive perfusion defects that did not change the scintigraphic probability for pulmonary embolism in any patient. Regarding zones of aerosol hyperdeposition, 76% had associated washout abnormalities on xenon; however, there was no correlation between the presence of these abnormalities or perfusion abnormalities. The results confirm the high sensitivity of 133Xe washout imaging, but suggest that radioaerosol imaging will detect most parenchymal abnormalities associated with perfusion defects of significance.

Adult↗
PubMed1993

99mTc-DTPA aerosol for same-day post-perfusion ventilation imaging: results of a multicentre study.

A multicentre study was performed in an attempt to evaluate a submicronic technetium-99m diethylene triamine penta-acetic acid aerosol generated by a newly developed delivery system, the aerosol production equipment (APE nebulizer), for same-day post-perfusion ventilation imaging in patients with clinically suspected pulmonary embolism. Quantitative comparison between the DTPA aerosol and krypton gas demonstrated a close correlation with respect to regional pulmonary distribution of activity and peripheral lung penetration (n = 14, r = 0.94, P < 0.001 and r = 0.75, P < 0.0025, respectively). In 169 consecutive patients, DTPA aerosol images performed immediately following perfusion (inhalation scan I) were compared to those carried out on the next day (inhalation scan II) with respect to image quality and assessment of perfusion-ventilation matches or mismatches. Agreement between inhalation scans I and II with respect to perfusion defects matched or mismatched to ventilation was found in 166/169 (98%) studies. The image quality of inhalation scan I was equal to that of scan II in 72%; inhalation scan I was superior in 11% of cases, while scan II was superior in 17%. This submicronic 99mTc-labelled DTPA aerosol is well suited for fast same-day post-perfusion ventilation imaging in patients with clinical suspicion of pulmonary embolism.

Aerosols↗
PubMed2006

Localization of 131I-labelled monoclonal antibody ERIC1 in a subcutaneous xenograft model of neuroblastoma in SCID mice.

PURPOSE: To evaluate a novel strategy of immunolocalization of human neuroblastoma by targeting the neural cell adhesion molecule (NCAM), which is over-expressed on neuroblastoma. METHODS: NCAM expression on the cell surface of established neuroblastoma cells was shown by flow cytometry. A SCID mouse model using IMR5-75 neuroblastoma cells to induce subcutaneous tumour growth was established. 131I was used to label monoclonal NCAM specific ERIC1 antibodies generating the 131I-ERIC1 antibody, which showed a high affinity to NCAM also after labelling (KD=9 x 10(-8) mol . l(-1)). RESULTS: Measurement of organ-specific radioactivity showed low organ-specific uptake (5.33%ID/g (percent of injected dose per gram of tissue) after 72 h), which continuously decreased over the 96 h investigation period, demonstrating clearance of radioactivity. In contrast, tumours accumulated radioactivity continuously up to a peak of 42.07%ID/g at the 96 h time point (31.07%ID/g at 72 h). This specific uptake could be blocked by application of unlabelled ERIC1 antibodies. Measurement of blood specific radioactivity revealed a characteristic clearance over the first 72 h. With 37 Gy, tumour-specific radioactivity reached therapeutic doses after 96 h. CONCLUSIONS: These results indicate that 131I-labelled ERIC1 has the ability to probe NCAM-expressing tumour cells in vivo with high efficiency and is a promising reagent for the diagnosis and treatment of NCAM-positive human tumours, especially for neuroblastoma.

Animals↗
PubMedDate not supplied

The reliability of probability analysis in the prediction of coronary artery disease in two hospitals.

To assess the accuracy of the Bayesian computer program CADENZA for the prediction of coronary artery disease, the authors examined the probabilities generated by the application of this program to the clinical and noninvasive test results of 303 patients in a private referral center and 199 patients in a veterans' hospital. These probabilities were compared with those produced by applying a six-variable discriminant function derived by logistic regression at the private referral center. Two statistical approaches were employed in evaluating the relative performances of the Bayesian program and the discriminant function. The first of these involved the sorting of patients in both test groups into ascending deciles of probability and comparing expected probability with observed angiographic disease prevalence in each decile. The second involved the calculation and comparison of a standardized reliability measure. The latter was significantly lower for the discriminant function both at the private hospital (0.200 for the discriminant function versus -17.5 +/- 1.96 for the Bayesian program) and at the veterans' hospital (-0.8 +/- 1.96 for the discriminant function versus -11.3 for Bayesian program). This suggests that the discriminant function is significantly superior to the Bayesian algorithm CADENZA for predicting coronary artery disease probabilities in subjects who have relatively high pretest disease probabilities.

Bayes Theorem↗
PubMed1982

Effective penetration of the lung periphery using radioactive aerosols: concise communication.

Radioactive microspheres could offer several advantages over gases in the investigation of pulmonary ventilation. Monodisperse microspheres of human serum albumin have been produced using a spinning-disc generator, and kits were prepared for subsequent labelling with technetium-99m. The average labeling efficiency was 88% and unlabeled Tc-99m was removed before aerosol delivery. A simple system was constructed to nebulize and deliver dry monodisperse microspheres. The ventilation images obtained were compared quantitatively with the corresponding krypton-81m images, subdividing the lung regions into inner, central, and peripheral zones. No significant difference was found in the proportions of the total counts for any lung region. There was good agreement between the distributions of microspheres obtained on separate days (r = 0.97, p less than 0.0001), An "aerosol penetration index" was defined as the ratio of the peripheral to the inner counts for the microspheres normalized by the corresponding ratio for krypton-81m. The mean value of this index for 16 normal subjects was 0.98 +/- 0.23 (s.d.), indicating that the microspheres had achieved penetration of the lung periphery. For patients with chronic obstructive lung disease, more localized defects were observed with the microspheres than with krypton-81m. The mean penetration index for this group was only 0.69 +/- 0.21 (s.d.). This was significantly different from the value for normal subjects (p less than 0.002).

Humans↗
PubMed1998

Variability of quantitative scintigraphic salivary indices in normal subjects.

UNLABELLED: Several quantitative measures of salivary uptake and discharge have been proposed recently in the scintigraphic evaluation of xerostomia. We investigated the scatter of four time-activity curve C(TAC)-derived indices in a group of volunteer subjects who met extensive inclusionary and exclusionary criteria of salivary normalcy. METHODS: Thirty-one adult volunteers underwent dynamic salivary scintigraphy with gustatory stimulation. Any candidates with subjective xerostomia, conditions or medications associated with dry mouth, salivary gland enlargement or pregnancy were excluded from study. All subjects had normal oral exams, xerostomia scores and unstimulated whole-mouth salivary flow rates. After the intravenous administration of 99mTcO-4, scintigraphy was performed with generation of TACs derived from regions of interest centered about the four major salivary glands and the oral cavity. At 45 min postinjection, hard lemon candy was given for 15 min as a gustatory stimulus. The following functional indices were calculated for each gland: partitioned percentage (PP) of total prestimulated activity, maximum net uptake ratio (NUR) and its time of occurrence (TNUR) and percentage stimulated discharge fraction (DF). RESULTS: The following ranges were observed: parotid PP, 22%-49%; submandibular PP, 4%-31%; parotid NUR, 2.2-16.0; submandibular NUR, 1.4-16.2; parotid TNUR, 8-45 min; submandibular TNUR, 2-45 min; parotid DF, 20%-99%; and submandibular DF, 27%-98%. Every subject except one 91-yr-old man showed frequent periodic unstimulated oral transfer of salivary activity with a rising oral TAC and responded to gustatory stimulation. CONCLUSION: So-called quantitative indices may perform poorly in the scintigraphic evaluation of xerostomic patients because the effects of normal simultaneous glandular trapping, uptake, oral discharge and possible vascular washout combine to widen reference limits. Coordinated analysis of oral cavity and glandular activities, glandular index averaging and better temporal resolution may help improve diagnostic performance.

Adult↗
PubMed2002

Functional and morphologic evaluation of congenital urinary tract dilatation by using combined static-dynamic MR urography: findings in kidneys with a single collecting system.

PURPOSE: To assess combined static-dynamic magnetic resonance (MR) urography in the evaluation of congenital urinary tract dilatation in infants and children. MATERIALS AND METHODS: Sixty-two patients with urinary tract dilatation underwent prospective examination with combined static-dynamic MR urography. A combination examination involved use of a static T2-weighted three-dimensional inversion-recovery fast spin-echo sequence and a dynamic T1-weighted two-dimensional fast field-echo sequence with gadopentetate dimeglumine-DTPA and furosemide application. Twelve additional patients underwent examination with only static MR urography. Thus, both image quality and morphologic features were assessed in 74 patients with the use of MR urography. The results were compared with those of ultrasonography and, when available, conventional urography or surgery. In 62 patients, the dynamic sequence was used to calculate split renal function from renograms generated from parenchymal regions of interest and to assess urinary excretion from whole-kidney renograms. Results were compared with those of diuretic renal scintigraphy (DRS) for split function (Spearman rank correlation coefficient) and urinary excretion (kappa coefficient). RESULTS: Stenoses at the ureteropelvic (n = 33) and ureterovesical (n = 31) junctions and within the ureter (n = 3) and nonstenotic dilatation (n = 23) were clearly depicted, while the normal urinary tract (n = 51) was depicted in its entirety in 47 of 51 examinations. Image quality was considered good or excellent in 95% of the kidney-ureter units. For split renal function, dynamic MR urography and DRS showed significant correlation (r = 0.92, P <.001). For urinary excretion, MR urography and DRS showed strong agreement (kappa = 0.67), with concordant classification of urinary excretion in 59 (81%) of 73 abnormal kidney-ureter units and in all 47 (100%) normal kidney-ureter units. CONCLUSION: Combined static-dynamic MR urography provides high-quality depiction of the urinary tract in infants and children, while allowing accurate determination of single-kidney function and reliable evaluation of urinary excretion.

Child↗