Biomedical subjects

V Obradović

Publications and source records attributed to V Obradović.

At least 19 recordsLinked to original sources

PubMed2006

[Hepatobiliary scintigraphy in evaluation of liver transplant function].

The aim of the study is evaluation of hepatocellular function, as well as morphology and patency of the biliary three of the liver transplants by dynamic hepatobiliary scintigraphy. The study was performed in 10 controls and 10 patients after orthotopic transplantation (up to two years). Sixty minutes dynamic acquisition (1 frame/min) was performed with scintillation camera after injection of 360 MBq 99mTc-diethyl- IDA. Hepatobiliary scintigrams were analysed for morphology, and parenchymal and hepatobiliary TA curves were generated and analysed as regard to the time to maximal acitivity (Tmax) and the time to half of maximum acitivity (T1/2). Uptake of the radiopharmaceutical was slightly but not significantly delayed (Tmax=18.5 +/- 2.9 min) in comparison to the controls (Tmax=14.2 +/- 3.4min), while excretion was significantly prolonged (T1/2=59.5 +/- 12.1 min) than physiological (Tmax=34.2 +/- 4.1min). Intrahepatic bile flow was nonsignificantly prolonged (Tmax=31.3 +/- 3.7 min) in comparison to the controls (Tmax=25.7 +/- 3.5 min) while extrahepatic one is high significantly prolonged (T1/2=89.0 +/- 14.3 min) than physiological (T1/2 =45.0 +/- 7.2 min). Biliary phase of hepatobiliary scintigraphy showed increased accumulation of radiopharmaceutical in the left (n=1) or right (n=2) hepatic duct. Radionuclide methods are noninvasive, and apear to be sensitive and valuable for the monitoring of liver transplants.

Biliary Tract↗

PubMed2005

[Methods for the quantification of left ventricular volumes assessed by radionuclide ventriculography (first part)].

The purpose of this study was to point out the existing methods and to describe and evaluate the accuracy of new, original, "Geometric-count-based" (GCB) method, based on radionuclide ventriculography, for the measurement of left ventricular volumes compaired to the contrast ventriculography. By having done this, the aim was to compare the accuracy of GCB method and other two radionuclide methods available for left ventricular volume measurements: Count-bases Massardo method and gated blood pool SPECT method. In GCB method count based data from radionuclide ventriculography were combined with geometric ones assuming a prolate ellipsoid left ventricular's shape with identical short axes. The following equation for computing left ventricular end-diastolic volume was developed: EDV = 2 x c x M x C(tot)/C(max), (1) where: 2c--manually drown short axis of prolate ellipsoid (left ventricle) at end-diastolic frame, M-calibrated pixel size, C(tot)--total counts in left ventricular's region of interest at end-diastolic frame, C(max)--maximum pixel counts in left ventricular's region of interest. Physical experiments with two different heart shaped phantoms were used to compare volumes assessed by all three radionuclide methods with the true volumes. The true volumes of cylindrical and ellipsoid phantoms of 112.5 ml and 190.5 ml, were computed to be 114 ml and 196 ml by our GCB method, 168 ml and 180 ml by Massardo method and 142 ml and 222 ml by gated blood pool SPECT methods, respectively. In clinical study, in 65 patients volumes assessed by radionuclide methods were compared to volumes measured using single plane contrast ventriculography as a gold standard. A good correlation of our original method was obtained with a contrast ventriculography for both EDV/m2 and ESV/m2 (r = 0.94, r = 0.92), slightly lower for Massardo method (EDV/m2: r = 0.90, ESV/m2 : r = 0.89) and significantly lower for gated blood pool SPECT (EDV/m2: r = 0.85, ESV/m2: r = 0.81, p < 0.01). In conclusion, both, phantom and clinical studies indicate that GCB radionuclide method is accurate, noninvasive for left ventricular volumes' measurement and should be widely used in everyday clinical practice.

Contrast Media↗

PubMed2005

[Scintigraphic diagnosis of inflammation and infection].

Nuclear medicine, diagnostic and therapeutic application of open sources of ionizing radiation in medicine, has wide range of possibilities for non-invasive infection and inflammation detection. The broad spectrum of methods, some of which are already in routine use while the others are still in the phase of investigation, improvement, or clinical trials, is presented. Most of the methods in routine use are capable of detection and localisation of both inflammation and infection. Antibiotic and antimicrobe peptides labelings have the possibility to diagnose infection and to differentiate it from inflammation, which is not the case with other scintigraphic methods. Availability of the radiopharmaceuticals and nuclear-medicine equipment, radiation exposure of the patient, clinical situation, the baseline pathophysiology of a process, and costs are the factors which contribute to the choice of the diagnostic approach. In order to ease the choice of the appropriate diagnostic method for inflammation/infection detection in different clinical situations, the recommendations from the ISORBE (International Society of Radiolabelled Blood Elements) are quoted.

Humans↗

PubMed2005

[Radionuclide detection of Helicobacter pylori infection].

The aim is the assessment of the HP infection in stomach using breath test and comparison to other diagnostic methods, as well as following up the effect of therapy. In 83 patients with digestive discomfort rapid urease test, histology and breath test were performed, while in 25 patients with proven HP infection the effect of therapy was followed up using breath test and clinical findings. For rapid urease test and histology, samples were taken from antral mucosa. Breath test was performed after per oral administration of the capsule of 14C- urea (37 kBq) (Izotop, Hungary and Laboratory for radioactive isotopes, Vinca) which, in the presence of Helicobacter pylori breaks up to 14CO2 and NH3. Radioactivity was measured by beta counter in the exhaled air fasting and 30 minutes after ingestion of the capsule. According to our results, the rise of activity over 100% was considered positive. From 83 patients, 58 were breath test was positive, 24 negative and one equivocal. Fast urease test was in 54 positive, in 29 negative while histology was in 57 postitive and 26 negative. Findings of the breath and urease tests were in accordance in 93% patients while breath test and histology in 98% patients. During follow up of the therapeutic effects, breath test and clinical findings were in accordance in 98% patients. Breath test can be useful in diagnosis but is a method of choice in following up the patients after therapy for H. pylori infection, because it is non-invasive, fast and precise.

Breath Tests↗

PubMed2005

[Implementation of the radiolabelled antibiotic in the detection of orthopedic infections].

The aim of the study is detection and evaluation of the orthopedic infections using 99mTc-ciprofloxacin, radiopharmaceutical supposed to distinguish inflammation from infection. There were 15 true positive findings, 9 true negative, and two were false positive, while 1 was false negative. Sensitivity was 94%, specificity 82%, positive predictive value 88%, negative predictive value 90% and accuracy 89%. According to our results, scintigraphy with 99mTc-ciprofloxacin is a useful method for detection and assessment of exact localization of orthopedic infections, which might be useful for (differential) diagnosis, surgical treatment in due time as well as monitoring of the treatment of conservative therapy.

Arthritis, Infectious↗

PubMed2005

[Initial 111In-platelet kinetics: indicator of platelet sequestration/destruction site or quality control of platelet labelling?].

Taking into consideration the existing disagreement in the literature, the aim of this paper was to estimate the value of the initial kinetics of autologous platelets labelled with 111In-oxinate, performed during the first 20 minutes after their intravenous injection. Two hypothesis were tested: 1. Initial 111In-platelet kinetics indicates the platelet sequestration site (in patients with normal mean platelet life span)/destruction site (in patients with shortened mean platelet life span), 2. Initial 111In-platelet kinetics indicates the quality of platelet separation and labelling procedure. We performed initial labelled platelet kinetics in thrombocytopenic patients (in order to test the first hypothesis) as well as in control (healthy) subjects (in order to test the second hypothesis). Thirty-nine persons were investigated: 33 with thrombocytopenia: 25 with shortened mean platelet life span, caused by chronic im mune thrombocytopenic purpura (ITP), eight with normal platelet life span and thrombocytopenia caused by myelodysplastic syndrome (MDS), six healthy, control subjects (C). In all 39 persons platelet blood count on the day of platelet labelling was determined, autologous platelet labelling with 111In-oxinate was performed, general and differential yields of platelet labelling (GYL and DYL), as well as mean labelled platelets life span were determined. Besides that, initial labelled platelets kinetics was performed with initial 111In-platelets accumulation in the liver (IPAL) calculation, as well as the late platelet kinetics for platelet sequestration index and platelet sequestration/destruction site determination. We obtained two types of initial labelled platelets kinetics (not only in the patients with shortened platelet life span, but also in the subjects with normal labelled platelets life span), which differed in the IPAL value and in the ratio of the liver and the heart radioactivity: IPAL < 20% and IPAL>20%. We found statistically significant difference in GYL and DYL between the two groups: IPAL<20% and IPAL > 20%. Both yields were higher in IPAL<20% group. There was no significant difference between the two IPAL groups in the platelet blood count, labelled platelet life span, sequestration index and sequestration site. No correlation could be found between IPAL on one side and platelet blood count, sequestration index, and sequestration site on another. We concluded that initial labelled platelet kinetics could not indicate the platelet sequestration/destructon site (which is accomplished by the late labelled platelets kinetics), but nevertheless, it is very sensitive and useful method of platelet separation and labelling quality control. While in vitro quality control parameters (GYL and DYL) indicate the quality of only one part of this procedure, initial labelled platelet kinetics reflects discrete platelet function disturbance that might happen from the moment of blood sample collection till the labelled platelets intravenous injection.

Adult↗

PubMed2005

[Prediction of the splenectomy efficacy in chronic immune thrombocytopenic purpura].

The aim of this investigation was to estimate the possibility of predicting the splenectomy response in patients with chronic immune thrombocytopenic purpura (ITP). The patients' age, sex, megakaryocytes abundance, platelet blood count, production, life span, sequestration/destruction site were considered as possible predictive factors. Thirty-four ITP patients (23 female and 11 male) aged from five to 83 years were investigated. Platelet blood count ranged from 4 to 106 x 10(9)l (mean value was 43 x 10(9)/l). Megakaryocyte abundance was determined in 19/34 ITP patients. Megakaryocytes were numerous in 11/19, present in 7/19 ITP patients and in one patient low megakaryocyte number was registered. In all 34 ITP patients autologous platelet labelling with 111In-oxinate was performed and labelled platelets were reinjected to the ITP patients. This enabled platelet life span, production, sequestration index and sequestration/destruction site determination. Platelet life span ranged from 0,4-5 days (mean value was 1 day). Mean value for platelet production index was 1,1. Platelet sequestration/destruction site in 16 ITP patients was the spleen, and in two it was the liver. Mixed platelet sequestration/destruction site (the liver and the spleen) was registered in 7 ITP patients, while predominantly splenic sequestration/destruction was present in 9 ITP patients. All 34 ITP patients were later submitted to splenectomy, which is a therapeutic option in ITP. Splenectomy result was favorable in 28/34 ITP patients while it was unfavorable in 6/34 (17,6%). Highly significant correlation was noticed between the splenectomy result and platelet sequestration site (p < 0.01). On the other hand, there was no correlation between the splenectomy result on one side, and patient's age, sex, megakaryocyte abundance, platelet production, life span and blood count on the other. Splenectomy result was favorable in all ITP patients with splenic sequestration/detruction of labelled platelets. It was unfavorable in ITP patients with hepatic sequestration of labelled platelets. In ITP patients with mixed platelet sequestration (hepatic and splenic) there were more unfavorable than favorable splenectomy results. Non-invasive method of platelet labelling and platelet sequestration/ /destruction site determination makes easier the clinicians' and ITP patients' decision for the splenectomy in the case when the spleen is the only sequestration site of the labelled platelets, and against the splenectomy, when exclusively hepatic platelet sequestration/destruction is registered.

Adolescent↗

PubMed2005

[Liver hemangioma blood pool as a function of time].

UNLABELLED: Aim of the study was to determine the time needed for establishing maximal labelled red blood cell concentration in hemangioma by scintigraphic semiquantitative blood pool estimation as a function of time. PATIENTS AND METHODS: Eleven patients (eight females and three males) with total number of fourteen liver hemangiomas have been examined. Nine of them had solitary lesions and remaininig two patients had two and three liver hemangiomas, respectively. All patients underwent blood pool scintigraphy 40, 60, 120 and 180 minutes after in vivo labelling of autologous red blood cells using 740 MBq of 99mTc. After correction for radioactive decay of 99mTc and back-ground correction blood pool indexes, as hemangioma/heart and liver/heart counting rate ratios, have been calculated. RESULTS: Mean blood pool indexes obtained 40-180 minutes after in vivo red blood cell labelling did not differ significantly (p > 0.05) neither in hemangioma (0.84-0.86) nor in liver tissue (0.55-0.58). In every acquisition time hemangioma blood pool index was substantialy higher than that of liver tissue (p < 0.01). CONCLUSION: The results of the study indicates that labelled red blood cells concentration reaches its plateau before 40th minute following in vivo labelling. The concentration difference between hemangioma and liver tissue also does not differ significantly after 40th minute of blood pool examination. In most patients blood pool scintigrams taken 60, 120 and 180 minutes following in vivo RBC labelling do not contribute to diagnostic value of the method.

Erythrocytes↗

PubMed2004

[Modern diagnostic procedures of nasopharyngeal carcinoma].

The aim of this study is a research of single photon emission tomography (SPET) values with talium 201 and tehnetium 99m MIBI, comparing it with other methods CT, MRI and ultrasonography. In our investigation there were two groups of patients 24 treated with T1-201 and 17 with Tc-99m-MIBI. Before the therapy 7 patients had been tested with T1 201 and was 100% proved the sensibility, specificity, sensitivity and also 6 patients as really positive TP and 1 patient really negative TN. The same result was gotten in the group where TC 99m was used, where 3 of them were really positive and 1 negative. All discoveries were confirmed pathohistologically and leaning on this we determined the status of really positive and really negative patients. After the therapy there were 7 positive and 7 negative patients, and also one positive, and 2 negatives that were false, who were treated by thalium. On the basis of formula of sensibility these findings show that 77,8%, if it observed only a group of patients who were being tested after the therapy, while all sensibility of methode is 86.7%, where in the analise was included a group of patients at whom was registred the primary tumor. The specificity of the method for this group of patients after the therapy is 87.5%, and the whole 88.9% where the accuarsy is 82.4% in the group after therapy and the whole is 87.5%.

Adult↗

PubMed2003

[Detection of abdominal infections using radio-labeled antibiotics].

The aim of the study is detection of the abdominal infective foci using 99mTc-ciprofloxacin, radiopharmaceutical supposed to distinguish inflammation from infection. Twenty-one patient was investigated. There were 11 true positive findings, 7 true negative, two were false negative, while 1 was false positive. Sensitivity of the method was 79% and specificity 91%. According to our results, scintigraphy with infection is a useful method for detection and assessment of exact localization of deep seated bacterial infections, which might be useful for (differential) diagnosis, surgical treatment in due time as well as monitoring of the treatment of conservative therapy.

Abdomen↗

PubMed2003

[Indium 111-labeled antibodies in the detection of colorectal carcinoma].

The aim of the study is detection of the recurrences and metastases of colorectal carcinomas using (111)In labelled antibodies B72.3 in 14 patients. With tomography, we can access better distinction of tumour in comparison to other structures and estimation of its size. Other imaging methods (CT, US) have advantage in detection of liver metastases, while immunoscintigraphy is more specific for the assessment of malignant abdominal tumours and extrahepatic metastases. The first results point out that Oncoscint CR-103 can be useful in diagnosis of recurrences and metastases of colorectal carcinoma, viability assessment after radiotherapy and in the choice of the adequate surgical treatment in dependence of the spread of the disease.

Adenocarcinoma↗

PubMed2002

[Elective resection of the spleen--overview of resection technics and description of a new technic based on radiofrequency coagulation and dessication].

The authors present a short overview of the development of elective splenic resections. Past and present indications are presented. Contemporary hemostatic technique for elective splenic resection are discussed. An original new technique for transsegmental partial splenic resection using RF generator Radionic Cool Tip(without any aditional hemostatic procedures is presented. This technique is inovative and when use properly it is a practically zero blood loos technique. A patient with transsegmental splenic resection using RF generator is presented. Further clinical application of the technique is necessary.

Catheter Ablation↗

PubMed2001

Preinfarction angina prevents left ventricular remodeling in patients treated with thrombolysis for myocardial infarction.

BACKGROUND: It has been shown that preinfarction angina may have beneficial effects on infarct size and mortality. However, there are no studies that have serially assessed the impact of preinfarction angina on left ventricular (LV) function in a large series of patients. HYPOTHESIS: The study was undertaken to determine whether preinfarction angina (within 7 days before infarction) influences LV remodeling. METHODS: In all, 119 consecutive patients with acute myocardial infarction were serially evaluated by 2-dimensional echocardiography (on Days 1, 2, 3, and 7; at 3 and 6 weeks; and at 3, 6, and 12 months following infarction). Left ventricular volumes were determined using Simpson's biplane formula and normalized for body surface area. Wall motion score index and sphericity index were calculated for each study. Coronary angiography was performed before discharge. RESULTS: Preinfarction angina was detected in 39 of 119 patients. Initial echocardiographic and clinical data as well as the incidence of patent infarct-related artery and collaterals were similar for patients with and without preinfarction angina. In the subset of thrombolysed patients, patients with preinfarction angina showed decrease of LV end-diastolic and end-systolic volumes during the follow-up period (p = 0.033 and p = 0.001, respectively), and improvement of wall motion score index (p < 0.001) and ejection fraction occurred (p = 0.001), without changing of LV shape (p > 0.05); in addition, patients with preinfarction angina had smaller LV volumes and higher ejection fraction than did those without angina, from 3 weeks onward. These favorable effects were not detected in patients not treated with thrombolysis. CONCLUSIONS: These data indicate that preinfarction angina has an inhibiting effect on long-term LV remodeling in patients who underwent thrombolysis for first acute myocardial infarction. It appears that preinfarction angina has no impact on infarct size and early postinfarction LV function.

Angina Pectoris↗

PubMed2001

[Study of blood flow in liver hemangiomas using radionuclide angiography].

Hepatic radionuclide angiography (HRA) is a recognised method of investigation of liver blood flow disorders caused by: diffuse and focal diseases of liver parenchyma or disorders of blood flow in extrahepatic liver vessels. Hepatic perfusion index (HPI) based on Sarper's slope method is significantly lower in patients with e.g. liver cirrhosis, malignant primary and metastatic liver diseases and portal vene thrombosis, but not in patients with benign focal liver leasions. Determined in liver as a whole, HPI is a sensitive indicator of the presence of malignant liver tumours, but is within normal range in patients with hepatic hemangioma. The aim of the study was to investigate characteristic of blood flow in hemangioma itself, separately from but in relation to the liver blood flow, using hepatic radionuclide angiography. We have examined 12 patients with liver hemangioma confirmed mainly by positive 99mTc-labeled red blood cell scintigraphy, which diagnostic specificity for liver hemangiomas is near 100%. 8/12 hemangiomas resulted in photopenic areas on angioscintigrams, indicating lower blood flow, and rest were isoactive to surrounding liver tissue. Regions of interest have been delineated around the photopenic areas (hemangiomas) and surrounding liver tissue. Time-activity curves have been generated and slope of the fitted hepatic artery and (portal) venous portions of the hemangioma and liver curves have been determined. Perfusion indexes of hemangioma (PIH) and liver (HPI) have been calculated from the slopes, expressing portal venous flow as a portion of entire blood flow to the region. In addition, times of arrival and transit of intravenous bolus of 99mTc-pertechnetate through the hemangioma and liver tissue have also been derived from time-activity curves. Slope of the venous portion of the hemangioma time-activity curve is significantly lower then that of the venous portion of the liver curve (p < 0.01). So that, perfusion index of hemangioma (PIH = 0.34 +/- 0.12 (mean +/- SD) is significantly lower then hepatic perfusion index (HPI = 0.57 +/- 0.08) (p < 0.05). Bearing in mind interference of superimposed liver activity with that of hemangioma, these results indicate that liver hemangiomas are dominantly if not exclusively irrigated by hepatic artery branches. There are no data regarding relation between arterial and venous blood flow in liver hemangiomas determined by HRA. Obtained results are in harmony with arteriography data which confirm slow arterial blood flow through hemangiomas. Portal venous inflow of some angiomatous liver lesions in infants and children, and arterio-portal shunting in hemangiomas have been rarely reported. Results of this study indicate that regional determination of perfusion index and other HRA parameters in patients with focal liver lesion enables differentiation between tissues with different intensity and pattern of blood flow. The method could be used in examination of vascularisation pattern of other focal liver lesions.

Erythrocytes↗

PubMed2001

[Protoscolecides in the surgical treatment of hepatic echinococcosis--myth or reality].

Traditionally protoscolicidal agents have been used during conservative surgery for cystic liver hydatidosis to sterilize the cyst cavity and to avoid dissemination. Many surgeons questions the effect of the procedure due to lack of objective data and possible complications for their use. Recently introduced minimally invasive techniques--percutaneous (PAIR), endoscopic and laparoscopic--have reestablished the need for the evaluation of protoscolocidal agents.

Anthelmintics↗

PubMed2001

[Evaluation of enterogastric reflux in relation to functional status of the gallbladder].

The aim of the study was estimation of the relation between the gallbladder (GB) motility function and the presence and quantity of enterogastric reflux (EGR). We investigated 172 patients with: physiological GB function (filling and emptying)(FGB), impaired GB function (prolonged filling and ejection fraction < 45%) and afunctional gallbladder (AGB)(without visualization). The study was performed during 90 min (1 f/min) after i.v. application of 185 MB 99mTc-dietil IDA. After 30 min. test meal was given while at the end stomach was marked. According to the parameters from time activity curves over stomach and hepatobiliary system, the index of ERG was calculated, while GB filling and ejection fraction were estimated from the GB time/activity curve. We can conclude that EGR occurs more frequently in the patients with afunctional GB in comparison to those with functional and decreased motor function. Also, EGR quantity is in correlation with the impairment of the GB function.

Duodenogastric Reflux↗

PubMed2001

Aortal aneurysm as a cause of ileus.

A 62-year-old patient presented with flatulence, abdominal distension and other symptoms of ileus. Roentgenographic finding found compression on duodenum. Blood pool scintigraphy ((99m)Tc erythrocytes) showed aortal aneurysm, while simultaneous gastric emptying study with liquid meal ((99m)Tc-S-colloid) showed dislocation of duodenum and compression from abdominal aortal aneurysm.

Journal Article↗

PubMed1999

[The presence and significance of Helicobacter pylori in patients with enterogastric reflux].

The aim of the study is assessment of the relationship between enterogastric reflux and the presence of Helicobacter pylori infection as a factors that cause gastritis, peptic ulcer and adenocarcinoma ventriculi. The study was performed in 52 patients with different digestive disorders, using gamma camera, during 90 minutes (1 frame/min) after intravenous injection of 185 MBq 99mTc-dietil IDA in cubital vein. According to time activity curves from the region of hepatobiliary system and gaster, index of enterogastric reflux was assessed (EGR). There is no correlation between the presence of Helicobacter pylori and EGR (r = 0.181, DF = 52, P < 0.05). However, Helicobacter is present more frequently in the patients with positive EGR (p 0.01). However, there is no significant difference (p < 0.05) in reflux value in patients with both positive and negative finding of Helicobacter.

Duodenogastric Reflux↗