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PubMed2000

A threshold method to improve standardized uptake value reproducibility.

Although standardized uptake values (SUV) are widely used to quantify the uptake of 18F-fluorodeoxyglucose (18F-FDG) in tumours, there are systematic differences in the way this index is applied by different investigators. The aims of this study were to compare the effects of using maximum or mean region counts in the calculation of SUV and to investigate an alternative technique based on a fixed fraction of the maximum counts. Simulated PET projections of the thorax were generated together with spherical lesions that varied in diameter from 1.6 to 4.8 cm with uptake values of 2, 4 and 8. The lesion SUVs were determined using either the maximum (SUVmax) or mean count (SUVmean) values found in regions circumscribing the lesion. In addition, average values were calculated that only included region pixels that exceeded a selected fraction of maximum value (SUV0.6max or SUV0.75max). These methods were also applied to six clinical 18F-FDG PET studies with a total of 12 lesions. The SUVs for these lesions were determined independently by four observers. Decreases with respect to SUVmax of 57%, 23% and 14% were found for SUVmean, SUV0.6max and SUV0.75max approaches respectively in the simulation study. The variation in SUVmean with region size was 35%, while the SUV0.6max and SUV0.75max was less than 3%. Similar results were obtained for the clinical data. We conclude that the proposed technique produces SUVs that are essentially independent of lesion region size and shape. It is expected that this will provide a more stable and reliable result than current approaches.

Adult↗
PubMed1996

Age-related reduction in 99Tcm-DTPA alveolar-capillary clearance in normal humans.

Age is known to reduce the efficacy of body organs and systems, even in the absence of disease. The alveolar-capillary clearance (ACC) rate is representative of the alveolar-capillary barrier's functional state. We studied 29 healthy non-smokers, who were selected after clinical and radiographic evaluation. The patients were divided into three groups based on age: Group I, < or = 30 years (n = 10); Group II, 31-55 years (n = 9); Group III, > or = 56 years (n = 10). Each patient inhaled 750 MBq 99Tcm-diethylenetriamine pentaacetate (99Tcm-DTPA) aerosol generated by a Venticis nebulizer (particles with a mean diameter of 1.1 microns) for 5 min. Forty frames of 30 s duration each were acquired and the ACC rates for the right and left lungs determined using a computer program. The mean ACC rates for the three groups were as follows: Group I, 1.31% min-1; Group II, 1.08% min-1; Group III, 0.76% min-1. The differences between Groups I and III (P < 0.001) and Groups II and III (P = 0.03) were shown to be significant. There was no significant difference between Groups I and II. Possible explanations for an age-related reduction in ACC rates include a reduction in the internal alveolar surface, the closure of the small airways, a reduction in the lung blood capillaries and a reduction in cardiac output. We conclude that there appears to be an age-related reduction in ACC rates in healthy non-smokers, even in the absence of clinically and radiographically detectable lung disease. However, larger studies are required.

Administration, Inhalation↗
PubMed1989

Hepatic reticulo-endothelial function: a correlation of radioisotopic and immunohistochemical assessment.

Using an immunoperoxidase staining technique for muramidase (lysozyme)-containing cells in liver biopsies, the Kupffer cell population has been compared with the isotope liver scan abnormalities in 43 patients with various liver diseases. A significantly greater degree of scintigraphic abnormality was seen in cirrhotics compared with non-cirrhotics using both a visually assessed scan scoring technique (p less than 0.001) and computer-generated spleen-to-liver (S-L) relative activity ratios (p less than 0.01). The mean muramidase-positive cell count in cirrhotic biopsies was not significantly different from that in non-cirrhotics, neither was there any significant difference between alcoholic and non-alcoholic liver disease. The liver mass was shown to be significantly greater (p less than 0.02) in alcoholic compared with non-alcoholic disease, but even if corrections were made for this, no significant differences were found. A significant (p less than 0.02) negative correlation was found between liver scan score and muramidase-positive cell count in patients with cirrhosis but not in non-cirrhotic disorders. No significant correlations were observed if the computer-derived liver mass was taken into consideration. These results suggest that the scan defect seen in liver disease cannot be explained by loss of Kupffer cells alone, although they are consistent with the hypothesis that intrahepatic shunting plays a significant role. Chronic alcohol ingestion does not in itself appear to be a major independent influence.

Adult↗
PubMed1989

Immunolocalisation and imaging of small cell cancer xenografts by the IgG2a monoclonal antibody SWA11.

We describe here a murine monoclonal antibody of the IgG2a isotype which was generated against the SW2 human small cell carcinoma cell line. The antibody, SWA11, was shown to bind to a partially defined antigen preferentially expressed on cell lines of small cell carcinoma origin. In vitro binding studies revealed 6.1 x 10(5) antigenic sites on the SW2 cell line and the Ka to be 1.2 x 10(9)M-1. Following injection into mice bearing 1-2 cm3 SW2 xenografts, SWA11 showed strong selective accumulation in the small cell heterotransplants with a tumour to blood ratio of 7.5:1 at day 4. Other tumour to organ ratios were similarly high at 19:1, 22:1 and 12:1 for liver, kidney and spleen respectively. The absolute amount of SWA11 which localised was 10.5% of total injected material per gram tumour at day 2 and this level did not markedly decrease by day 4. The high ability of SWA11 to localise to SCC xenografts was confirmed by external gamma scintigraphy. The potential application of SWA11 as a model system for in vivo radioimmunotherapy is discussed.

Animals↗
PubMed2004

Biodistribution and dosimetry of (99m)Tc-depreotide (P829) in patients suffering from breast carcinoma.

OBJECTIVE: This paper reports on the biodistribution and dosimetry of (99m)Tc-depreotide in patients. METHODS: Whole body planar images were acquired 30 minutes, 1, 2, 4, 9, and 24 hours after intravenous injection of 555-740MBq (99m)Tc-depreotide in 5 breast cancer patients. Urine was collected up to 24 hours after injection, allowing for a calculation of renal clearance and an interpretation of whole body clearance. Time activity curves were generated for the thyroid, lungs, liver, spleen, kidneys, colon, thoracic vertebrae/sternum, and whole body by fitting the organ-specific geometric mean counts, obtained from regions of interest (ROIs). The Medical Internal Radiation Dose (MIRD) formulation was applied to calculate the absorbed radiation dose for various organs. RESULTS: The whole body images show most of the activity distributed in the liver, spleen, and kidneys. Nearly all excretion of activity occurred by the renal system, and hepatobiliary excretion was negligible. Elimination of administered activity occurred predominantly through physical decay. The mean cumulative measured urinary excretion at 24 hours postinjection was 14.0% (standard deviation; 11.8%) of the administered activity. The highest absorbed dose was received by the kidneys, thyroid, and spleen. The average effective dose was estimated to be 1.15E-02mSv/MBq (standard deviation; 1.41E-03mSv/MBq). CONCLUSION: The biodistribution of (99m)Tc-depreotide demonstrated low lung and myocardial uptake allowing early imaging of the supradiaphragmatic region and this with a dosimetry favorable for clinical whole body and single photon emission computed tomography (SPECT) imaging.

Breast Neoplasms↗
PubMed1980

HIDA scanning in gall-bladder disease.

HIDA labelled with 99Tcm is a new hepatobiliary imaging radiopharmaceutical which is selectively taken up by the liver and excreted into the biliary tree; it has been shown to demonstrate the gall bladder in normal subjects. Using a gamma-camera computer system, dynamic liver scans were performed during the first hour on 97 patients who, on the basis of standard investigations and on the findings at surgery, were divided into six groups as follows. 1. Normal. 2. Hepatocellular disease. 3. Biliary obstruction. 4. Chronic gall-bladder disease. 5. Acute gall-bladder disease. 6. Acute abdomen (not due to gall-bladder disease). Pictures were taken and activity-time curves of "regions of interest" were generated from the computer data. From these the presence or absence of a gall-bladder image was easily determined. The gall bladder was visualized in all normals but in none of the patients with acute gall-bladder disease. In the group with an acute abdomen suggestive of acute gall-bladder disease, but subsequently shown to be otherwise, the gall bladder was visualized in all cases. The gall bladder was not visualized in 42% of hepatocellular disease patients, nor in any of those with biliary obstruction, due to poor uptake or poor secretion of the HIDA. In cases of chronic gall-bladder disease, visualization of the gall bladder corresponded with gall-bladder opacification on the oral cholecystogram; in these cases the HIDA scan offers no advantage over the oral cholecystogram. These results suggest that in cases of "acute abdomen" an absent gall bladder image with a normal hepatogram will strongly support the diagnosis of acute gall-bladder disease, and that visualization of the gall bladder excludes such a diagnosis, making the HIDA scan a useful first-line investigation in these patients.

Abdomen, Acute↗
PubMed2006

[Recombinant TSH in ablative therapy and follow-up of patients with differentiated thyroid carcinoma].

The studies evaluating the efficacy and safety of recombinant TSH in the ablative therapy and follow-up of patients with differentiated thyroid carcinoma by serum thyroglobulin (Tg) measurement and iodine scanning were reviewed in this article. Recombinant TSH is comparable to hypothyroidism in the generation of Tg and in the execution of iodine-131 whole-body scanning, with the advantage of sparing patients from the symptoms of hypothyroidism and from impaired quality of life induced by levothyroxine withdrawal, in addition to a reduced exposure to elevated TSH and shorter absence from work, with recombinant TSH being the preparation indicated for the diagnosis of metastases in both low risk (Tg after recombinant TSH) and moderate or high risk patients (Tg and iodine-131 scanning after recombinant TSH). In the case of ablative therapy, the results are promising when using a dose of 100 mCi for remnant ablation, but hypothyroidism is still preferred, except for patients in whom the desired TSH elevation after levothyroxine withdrawal is not achieved, patients with base diseases that are aggravated by acute and severe hypothyroidism (severe heart and lung disease, coronary disease, compromised renal function, history of psychosis due to myxedema), patients debilitated by advanced disease, and elderly individuals. The studies also show that the administration of recombinant TSH is safe, with few mild or moderate adverse effects.

Carcinoma↗
PubMedDate not supplied

Preliminary validation of the opposing view method for quantitative gamma camera imaging.

We perform gamma camera imaging to generate data for estimation of internal radiation dose in our radioimmunotherapy candidates. Because of the inability of single photon emission computed tomography (SPECT) to account for patient attenuation variability without serious error, quantitative planar imaging was performed to estimate the radioactive content of normal organs. We undertook the following studies to further validate this method. A realistic fillable human phantom was used to determine the accuracy of I-131 filled organ estimation. A transmission scan of the unfilled phantom was produced with an I-131 filled flat flood source. Anterior and posterior planar images of the filled organs were acquired with region of interest determination of the activity in the organ. Correction by the attenuation factor and a camera calibration factor yielded the MBq in the organ. The procedure was also performed in a simple phantom. Three dogs were imaged and sacrificed to validate the technique in vivo. A high degree of accuracy in estimation of organ radioactive content was found to be present using the phantom and dog models. Use of this method requires further validation but provides a solid basis for estimation of internal radiation dosimetry in radioimmunotherapy planning.

Animals↗
PubMed2001

Prediction of the usefulness of combined mammography and scintimammography in suspected primary breast cancer using ROC curves.

UNLABELLED: The aim of this study was to compare the accuracy of 99mTc-methoxyisobutylisonitrile scintimammography (SMM) and conventional mammography in patients presenting with suspected primary breast cancer. Receiver-operating-characteristic (ROC) curve analysis was applied to determine if a combination of x-ray mammography (XMM) and SMM was more accurate than a single test alone. METHODS: The results of SMM, XMM, and a combination of both studies performed over a 3-y period on 374 suspicious lesions in 353 patients with no previous history of breast cancer were reviewed. Each scan report was reviewed and graded as follows: grade 1, definitely normal or benign; grade 2, probably normal or benign; grade 3, equivocal; grade 4, probably cancer; and grade 5, definitely cancer. The results were verified by pathologic examination of biopsy material obtained from each suspicious mass. ROC curves were generated from these results. RESULTS: There were 204 malignant breast tumors and 170 nonmalignant breast lesions. SMM diagnosed correctly 181 breast cancers and was true-negative in 122 benign breast lesions: sensitivity, 89%; specificity, 71%; positive predictive value (PPV), 79%; and negative predictive value (NPV), 84%. XMM diagnosed correctly 143 malignant tumors and was true-negative in 117 nonmalignant lesions. The sensitivity, specificity, PPV, and NPV for XMM were 70%, 69%, 73%, and 66%, respectively. Using a combination of the two tests, the combined sensitivity was 93%, specificity was 72%, PPV was 80%, and NPV was 90%. Using the index of the area under the ROC curve obtained by the rating method showed that the combination of XMM and SMM was significantly more accurate than either of the individual tests if performed alone (P < 0.05). CONCLUSION: This study shows that the combination of XMM and SMM produces more accurate results than either modality alone. Therefore, if there is doubt about the accuracy of XMM, SMM should be used as the second-line test in breast imaging.

Adult↗
PubMed2001

Biodistribution and dosimetry of 99mTc-ciprofloxacin, a promising agent for the diagnosis of bacterial infection.

This study reports on the biodistribution and dosimetry of technetium-99m ciprofloxacin, a radio-ligand developed for the visualisation of bacterial infection. Whole body scans were performed up to 24 h after intravenous injection of 370 MBq 99mTc-ciprofloxacin in three male and three female volunteers. Blood samples were taken at various times up to 24 h after injection. Urine was also collected up to 24 h after injection, allowing calculation of renal clearance and interpretation of whole body clearance. Time-activity curves were generated for the thyroid, heart, liver and whole body by fitting the organ-specific geometric mean counts, obtained from regions of interest. The MIRD formulation was applied to calculate the absorbed radiation doses for various organs. The images showed rapid, predominantly urinary excretion of 99mTc ciprofloxacin, with low to absent brain, lung and bone marrow uptake and low liver uptake and excretion. Accordingly, imaging conditions are excellent for both the thoracic and the abdominal region, even at early time points (60 min) post injection. In none of the volunteers was the gallbladder visualised. Approximately 60% of the injected activity was recovered in urine by 24 h post injection. The highest absorbed doses were received by the urinary bladder wall, the thyroid, the upper large intestine, the lower large intestine and the uterus. The estimated mean effective dose for the adult subject, taking into account the weight factors of the ICRP60 publication, was 0.0083 mSv/MBq. The amount of 99mTc ciprofloxacin required for adequate planar and tomographic imaging results in an acceptable effective dose to the patient.

Adult↗
PubMed1987

Detection of coronary artery disease by thallium imaging using a combined intravenous dipyridamole and isometric handgrip test in patients with aortic valve stenosis.

Detection of coronary artery disease (CAD) in patients with aortic valve stenosis (AS) is clinically difficult. Thallium-201 images were generated in 27 patients with AS during combined intravenous dipyridamole and handgrip test, which induces a marked acute increase in coronary blood flow. Isolated AS was noted in 21 patients and combined AS and aortic regurgitation in 6. Thirteen patients had more than 50% diameter stenosis in 1 or more coronary arteries on angiography. Eleven of them had reversible perfusion defects on post-stress thallium scans (sensitivity 85%). Two patients had thallium defects without angiographic evidence of significant CAD (specificity 86%). In the other 12 patients with normal coronary angiographic findings, the thallium scans were normal. Two patients had dizziness and hypotension after dipyridamole infusion, which disappeared during the handgrip test; 2 others had chest pain during handgrip. One of them was treated with aminophylline and the other with aminophylline and nitroglycerin. No other adverse effects were reported by the patients and no major complications occurred during stress testing. Thus, thallium imaging during combined intravenous dipyridamole and handgrip test appears to be a promising noninvasive method of revealing CAD in patients with AS.

Aged↗
PubMed1994

How accurate is dobutamine stress electrocardiography for detection of coronary artery disease? Comparison with two-dimensional echocardiography and technetium-99m methoxyl isobutyl isonitrile (mibi) perfusion scintigraphy.

OBJECTIVES: This study was designed to establish the appropriate diagnostic criteria for positive dobutamine electrocardiographic (ECG) stress test results and to compare their accuracy with those of dobutamine two-dimensional echocardiography and perfusion scintigraphy. BACKGROUND: Conventional criteria for positive findings on ECG exercise testing may not be appropriate for use with dobutamine ECG stress testing. METHODS: One hundred twenty-nine consecutive patients with an interpretable ECG and without previous myocardial infarction were prospectively studied at the time of coronary arteriography. All completed a standard dobutamine protocol (5 to 40 micrograms/kg body weight per min in 3-min dose increments) without side effects. Significant coronary artery disease, defined as > 50% lumen diameter stenosis of a major epicardial coronary artery on coronary angiography, was present in 83 patients. Empiric receiver operating curves were generated for various ECG criteria derived from computer-averaged signals. RESULTS: The best ECG criterion, with a sensitivity of 42% and a specificity of 83%, was an ST segment shift, relative to baseline, of 0.5 mm 80 ms after the J point. The sensitivity of this criterion was greater than that of the conventional criterion of 1-mm ST segment depression 60 (23%) or 80 (18%) ms after the J point, was comparable to that of chest pain occurring during the test (44%, p = NS) but remained inferior to the sensitivities of technetium-99m methoxyl isobutyl isonitrile (mibi) perfusion (76%) or stress echocardiography (76%, p < 0.001, for both). The specificity of this criterion was not significantly different from that of technetium-99m mibi perfusion tomography (65%) or stress echocardiography (89%) but was superior to that of chest pain (59%, p < 0.025). CONCLUSIONS: We conclude that this new criterion for dobutamine electrocardiography is specific but that an imaging technique is still required to accurately predict coronary artery disease.

Adult↗
PubMed1988

Biliary obstruction after cholecystectomy: diagnosis with quantitative cholescintigraphy.

Fifty patients with recurrent post-cholecystectomy pain underwent hepatobiliary scintigraphy. Time-activity curves were generated from regions of interest over the liver, bile duct, duodenum, and bowel. Patients were divided into obstructed and unobstructed groups with endoscopic retrograde cholangiopancreatography criteria. Measurements from the liver, duodenum, and bowel curves contributed little to the analysis. The washout phase of the bile duct curve showed intermittent emptying in both obstructed and unobstructed groups. Less than one-third of peak activity remained in both groups at 90 minutes. Retention fell more rapidly in the later portion of the sequence in patients with obstruction. Quantification was essential, since differences were subtle and could not be appreciated visually. In the absence of hepatocellular disease, the most reliable criterion was the time at which maximal bile duct activity occurred. A cutoff level of 29 minutes or more was used in the diagnosis of obstruction. A sensitivity of 93% with an adequate specificity of 64% and an overall accuracy of 80% was achieved in the prediction of obstruction.

Adult↗
PubMed1988

[Immuno-scanning of human colon cancer xenografts using a labeled monoclonal antibody to the carcinoembryonic antigen].

The results of experiments using 131I-labelled monoclonal antibody (131I-MoAb) were described. The experiments were staged on nude male mice with transplanted human colon adenocarcinoma of the 34th generation (RTK-12). Tumor sizes by the time of 131I-MoAb administration varied from 1 to 3 cm. 131I-MoAb specific radioactivity was 456.6 kBq/micrograms in the volume of 0.3 ml. The same amount of 131I-Na was administered to control animals. Scanning on the Scintimat-2F (Siemens) was performed 1, 2, 3 and 4 days after injection of 131I-MoAb. Three days before scanning 0.2% KI was added to the drinking water. Some animals were decapitated on the 2nd-3rd day for radiometry of organs and tissues. After the injection of 131I-MoAb 10-fold less than the CEA serum concentration and with specific radioactivity of 370-444 kBq its tumor accumulation in 48 h was 10-15-fold higher than that in the surrounding tissues resulting in better tumor scans. Intensive dehalogenation of 131I-MoAb in vivo and related 131I accumulation in the thyroid and adrenal glands (in the medullary layer) required the administration of stable iodine not only before but also after injection of the radioactive agent.

Adenocarcinoma↗
PubMed1989

Uptake and kinetics of Tc-99m hexakis 2-methoxy isobutyl isonitrile in benign and malignant lesions in the lungs.

Kinetics of Tc-99m MIBI uptake was studied in 19 patients with lung lesions (6 benign, 13 malignant). Two dynamic studies were acquired after the I.V. injection of 10-15mCi (370-550 MBq); the first was every second for 60 seconds, followed by a second one every minute for 30 minutes. Delayed images were acquired at two and three hours. By assigning regions of interest (ROI) over the lung lesions (TR), contralateral normal lung (NL) and the heart (Ht), time activity curves (TAC) were generated and time to peak activity was calculated as well as the ratios of TR/NL, Ht/TR and Ht/NL. The Ht/NL ratio was also assessed in five patients referred with diagnosis of ischaemic heart disease (IHD) for myocardial imaging. There was a localized increase of Tc-99m MIBI uptake in ten patients with untreated malignant tumours of the lung. No localized uptake was found in one patient with untreated poorly differentiated squamous cell carcinoma, two treated lung cancer and four patients with non-malignant lesions of the lungs. Two patients with fibrosing alveolitis showed diffuse increase lung uptake. In all positive studies peak tumour was reached within the first minute. There was no statistical difference in the ratio of Ht/NL between all groups except in patients with fibrosing alveolitis. There was no significant difference between the ratios TR/NL, Ht/TR and Ht/NL at 5-10 minutes and 25-30 minutes. The ratio of TR/NL at 25-30 minutes was 1.58 +/- 0.36 in the positive cases versus 1 +/- 0.22 in the negative ones.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Assessment of bile flow by radioscintigraphy in patients with biliary-type pain after cholecystectomy.

Scintigraphy of the biliary system using 99mTc di-isopropyl iminodiacetic acid (DIDA) was performed in 65 subjects who had previously undergone cholecystectomy. Of the 65 subjects, 20 were free of pain and 45 had biliary-type pain both with (group I) and without (group II) features of sphincter of Oddi dysfunction. This dysfunction comprised dilatation of the bile duct, a transient rise in serum levels of liver enzymes after episodes of pain, or both abnormalities. After computer acquisition of images at intervals of 60 seconds for at least 90 minutes, time/activity curves were generated for five regions of interest: liver, common hepatic duct, common bile duct, duodenum, and background. The time at which counts in the common bile duct reached 50% of maximum (CBD T50) and the time of first entry of isotope into the duodenum (TD) were used to compare asymptomatic subjects with those with biliary-type pain. Patients in group I, but not those in group II, showed significant prolongation of CBD T50 (p less than 0.002) and TD (p less than 0.02) when compared to values in asymptomatic subjects. Six patients had a second scan at six to 12 months after endoscopic sphincterotomy and all showed a reduction in values for CBD T50 and TD. In patients with pain, a significant correlation was shown between bile duct diameter and CBD T50 (p less than 0.01) and between bile duct diameter and TD (p less than 0.02) but results from scintigraphy were independent of responses to morphine-neostigmine and motility in the sphincter of Oddi as assessed by endoscopic manometry.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed2004

Augmented 18F-FDG uptake in activated monocytes occurs during the priming process and involves tyrosine kinases and protein kinase C.

UNLABELLED: Activated monocytes with a high (18)F-FDG accumulation can affect the results of clinical PET studies. To better understand the mechanisms regulating monocytic (18)F-FDG uptake, we investigated the effect of priming and respiratory-burst generation and further evaluated the role of potential protein kinase pathways. METHODS: Purified human monocytes were primed with interferon-gamma (IFN-gamma), and respiratory burst was generated by stimulation of primed cells with phorbol-12-myristate-13-acetate (PMA). Oxygen-intermediate generation was assessed by luminescence measurements after the addition of lucigenin. (18)F-FDG uptake after 30 min of incubation was measured for unprimed control cells, primed cells, and PMA-stimulated cells. The role of protein kinases was investigated using respective inhibitors. RESULTS: PMA stimulation of primed monocytes dramatically increased oxygen-intermediate generation, leading to a 42.2 +/- 1.1 fold higher level of cumulative luminescence compared with unprimed control cells, whereas IFN-gamma priming alone resulted in low luminescence levels (13.9% +/- 4.6% of PMA-stimulated cells). In contrast, priming alone was sufficient to augment monocytic (18)F-FDG uptake to 273.3% +/- 16.7% of control levels (P < 0.001), and it was not further increased by PMA stimulation. The tyrosine kinase inhibitor, genistein, and the specific protein kinase C inhibitor, staurosporine, completely abolished the priming-induced enhancement of (18)F-FDG uptake and lowered uptake to control levels. Under the same conditions, wortmannin, a phosphatidylinositol 3 kinase (PI3 kinase)-specific inhibitor, and cycloheximide, a protein synthesis inhibitor, were associated with only minor reductions in the enhanced-uptake effect of priming. CONCLUSION: IFN-gamma priming alone, without stimulation of respiratory-burst activity, is sufficient to induce maximal augmentation of (18)F-FDG uptake in monocytes. Furthermore, this metabolic effect appears to involve tyrosine kinases and the protein kinase C pathway but is independent of the PI3 kinase pathway.

Cells, Cultured↗
PubMed2005

Hemodynamic evaluation of varicocele: the role of scrotal scintigraphy and Doppler ultrasonography in the prediction of postoperative seminal improvement.

AIM: The aim of this study was to evaluate the hemodynamics of varicocele using Doppler ultrasonography and scrotal scintigraphy, and to compare the value of these two methods in the prediction of seminal improvement after varicocelectomy. MATERIALS AND METHODS: A total of 40 men with left sided varicocele presented for surgery because of infertility of at least one year in duration. Preoperative and postoperative sperm counts and per cent motility were obtained. Dynamic scrotal scintigraphy and Doppler ultrasonography were performed in all patients. Three perfusion patterns according to the time-activity curves (TAC) generated from scrotal perfusion images were defined. Type 1: radioactivity shows faster accumulation and maintenance of a higher level on the left side than on the right side. Type 2: time-activity curve rises gradually to a higher level on the left than on the right. Type 3: time-activity curve increases symmetrically and slowly on both sides. The relationship between preoperative TAC patterns and postoperative seminal findings, and preoperative Doppler grades and postoperative seminal findings were investigated. RESULTS: Improvement in total motile sperm counts was not statistically significant (37.8% +/- 3.2% versus 45.2% +/- 8.5%) (p = 0.751). Following varicocelectomy, sperm concentration (million sperm per ml) increased from 16.9 +/- 3.3 to 26.6 +/- 8.6 (p = 0.015). According to the Doppler examinations, postoperative improvement in sperm concentration was demonstrated in patients with grade 1 varicocele (66%). Scintigraphic evaluation showed improvement in patients showing TAC-2 and TAC-3 patterns (63%). CONCLUSION: Local hemodynamics of varicoceles demonstrated by scintigraphy and Doppler seemed to be different. Grade 1, TAC-2 and TAC-3 patients may be better candidates for varicocelectomy. Scintigraphy and Doppler ultrasonography showed similar success rates in the prediction of improvement following varicocelectomy in the present study.

Adult↗