Ischemia-guided vs routine non-culprit vessel angioplasty for patients with ST segment elevation myocardial infarction and multi-vessel disease: the IAEA SPECT STEMI trial.

BACKGROUND: In patients with multi-vessel disease presenting with ST elevation myocardial infarction (STEMI), the efficacy and safety of ischemia-guided, vs routine non-culprit vessel angioplasty has not been adequately studied. METHODS: We conducted an international, randomized, non-inferiority trial comparing ischemia-guided non-culprit vessel angioplasty to routine non-culprit vessel angioplasty, following primary PCI for STEMI. The primary outcome was the between-group difference in percent ischemic myocardium at follow-up stress MPI. All MPI images were processed and analyzed at a central core lab, blinded to treatment allocation. RESULTS: In all, 109 patients were enrolled from nine countries. In the ischemia-guided arm, 25/48 (47%) patients underwent non-culprit vessel PCI following stress MPI. In the routine non-culprit PCI arm, 43/56 (77%) patients underwent angioplasty (86% within 6 weeks of randomization). The median percentage of ischemic myocardium on follow-up imaging (mean 16.5 months) was low, and identical (2.9%) in both arms (difference 0.13%, 95%CI - 1.3%-1.6%, P < .0001; non-inferiority margin 5%). CONCLUSION: A strategy of ischemia-guided non-culprit PCI resulted in low ischemia burden, and was non-inferior to a strategy of routine non-culprit vessel PCI in reducing ischemia burden. Selective non-culprit PCI following STEMI offers the potential for cost-savings, and may be particularly relevant to low-resource settings. (CTRI/2018/08/015384).

18F-FDG PET/CT in evaluation of squamous cell carcinoma.

OBJECTIVE: Squamous cell carcinomas (SCC) are a number of different types of cancer that result from squamous cells. These cells form on the surface of the skin, on the lining of the respiratory and digestive tracts etc. To evaluate SCC and frequencies of their localizations based on the findings of fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT). SUBJECTS AND METHODS: This study included 343 consecutive patients with SCC who were sent for the 18F-FDG PET/CT. Inclusion criteria were: Pathohistologically verified SCC; absence of malignancy of any other localization, as well as absence of infection; and glycemia ≤11mmol/L. RESULTS: The pathological findings on 18F-FDG PET/CT were present in 86% of patients. There was statistically significant difference in the finding of 18F-FDG PET/CT in relation to gender (P>0.006). The disease was more often present in women. The most common localizations of disease were: lungs (70%), vagina/cervix (18%), gastrointestinal tract (18%), head and neck (5%). Highest maximum standardized uptake value (SUVmax) levels were seen in the lungs 11.78±8.38, vagina/cervix 11.21±8.10, and head and neck area 6.32±3.96. CONCLUSION: Fluorine-18-FDG PET/CT can be informative in evaluation of SCC. Disease is present usually in women, although it is the same pathohistological type of disease, different organs accumulate this radioactive contrast differently.

Novel nuclear medical procedures in the detection of microvascular dysfunction.

Coronary microvascular dysfunction is present in two-thirds of patients showing symptoms and signs of myocardial ischemia. Their microcirculation has abnormalities due to endothelial and smooth muscle cell dysfunction. Impairment of this mechanism causes a high risk of adverse cardiovascular event. Diagnosing coronary microvascular dysfunction is challenging. Guidelines recommend the use of nuclear medicine procedures in the above-mentioned indications. Myocardial perfusion imaging with positron emission tomography is a novel procedure with high diagnostic accuracy and quality of images. It has short acquisition, low effective radiation dose and prognostic factors. There are still unknowns about this procedure and all its benefits.

Muscular sarcoidosis in the eyes of 18 F-FDG PET/CT.

PURPOSE: The aim of this study was to determine the frequency, symptoms, activity and pattern of muscle sarcoidosis, correlation with laboratory parameters, and to assess its therapy response with 18 F-FDG PET/CT. METHODS: Study included 90 patients with biopsy confirmed sarcoidosis and symptoms/biochemical/imaging findings suggestive of active disease. The exclusion criteria were: presence of cancer or other diseases that resemble sarcoidosis on PET/CT (Wegener syndrome, tuberculosis, aspergillosis), and the glucose level being greater than 11 mmol/L. All patients were screened for muscle sarcoidosis with 18 F-FDG PET/CT examination. Follow-up examination was done 1 year after the baseline in order to evaluate therapy response. RESULTS: Disease was very rare and present in only 7/90 patients. Most of the patients had polysymptomatic disease, while muscle pain was less frequent, present only in one-third of the patients. The disease was usually present in the lower limbs, upper limbs, and skeletal striated muscles. The most common pattern of disease was nodular. Disease activity estimated with SUVmax was not in correlation with the ACE findings, creatine kinase, and aldolase levels (p > 0.05). Follow-up PET/CT revealed complete remission in one patient and partial remission in two. CONCLUSION: 18 F-FDG PET/CT can be useful in asymptomatic young patients with nodular pattern of disease, who have easily relapsing form of disease. It can help in further management of these patients and can affect prognosis of the disease, since most of the laboratory parameters in this entity are within normal limits.

18F-FDG PET/CT value in the detection of seminoma and correlation with CT and tumor marker levels - up to 8 years of follow-up.

OBJECTIVE: Positron emission tomography/computed tomography using fluorine-18 fluoro-deoxyglucose (18F-FDG PET/CT) is not routinely used for diagnosis of testicular carcinoma. Unlike CT which cannot confirm with certainty the nature of the lesions, especially in post-therapy setting, 18F-FDG PET/CT detects active disease by showing increased glucose metabolism within the lesions. AIM: Determination of 18F-FDG PET/CT usefulness in detection of seminoma, therapy response evaluation and comparison to CT findings and tumor marker levels. MATERIAL AND METHODS: Eighty-two men (age 39.8±10.1) after orchiectomy and histopathological confirmation of seminoma were included in this study. Indications for 18F-FDG PET/CT were initial staging, restaging after chemo/radiotherapy with positive/uncertain CT, suspected recurrence on CT, elevated tumor markers. All patients had clinical follow-up of up to 8 years (median 33.5) after the first 18F-FDG PET/CT examination. Degree of metabolic activity was analyzed visually and semi-quantitatively using maximum standardized uptake value(SUVmax). RESULTS: Fluorine-18-FDG PET/CT was true positive in 36 patients (43.9%) with average SUVmax of 7.9±4.8.Recurrence was mostly found in retroperitoneal lymph nodes and distant metastases in lungs, bones, liver. Six findings were false positive and 3 false negative. Sensitivity, specificity, accuracy of 18F-FDG PET/CT were 92.3%, 86.0%, 89.0% and of CT 60.8%, 66.6%, 63.4%. Pearson Chi-square test showed statistically significant difference between the results of 18F-FDG PET/CT and CT (P=0.016). Significant correlation was found between positive 18F-FDG PET/CT findings and levels of LDH (P=0.043), while non-significant between AFP, ß-hCG (P>0.05). CONCLUSION: Fluorine-18-FDG PET/CT was superior to CT in evaluation of therapy response, active disease in residual tissue and normal size lymph nodes, as well as when CT was negative and tumor markers were elevated. Elevated lactate dehydrogenase (LDH) contributes to positive 18F-FDG PET/CT findings.

PET/CT features of extrapulmonary tuberculosis at first clinical presentation: a cross-sectional observational 18F-FDG imaging study across six countries.

BACKGROUND: A large proportion of the huge global burden of extrapulmonary tuberculosis (EPTB) cases are treated empirically without accurate definition of disease sites and extent of multi-organ disease involvement. Positron emission tomography (PET) imaging using 2-deoxy-2-(fluorine-18) fluoro-d-glucose (18F-FDG) in tuberculosis could be a useful imaging technique for localising disease sites and extent of disease. METHODS: We conducted a study of HIV-negative adult patients with a new clinical diagnosis of EPTB across eight centres located in six countries: India, Pakistan, Thailand, South Africa, Serbia and Bangladesh, to assess the extent of disease and common sites involved at first presentation. 18F-FDG PET/computed tomography (CT) scans were performed within 2 weeks of presentation. FINDINGS: 358 patients with EPTB (189 females; 169 males) were recruited over 45 months, with an age range of 18-83 years (females median 30 years; males median 38 years). 350 (98%) out of 358 patients (183 female, 167 male) had positive scans. 118 (33.7%) out of 350 had a single extrapulmonary site and 232 (66.3%) out of 350 had more than one site (organ) affected. Lymph nodes, skeleton, pleura and brain were common sites. 100 (28%) out of 358 EPTB patients had 18F-FDG PET/CT-positive sites in the lung. 110 patients were 18F-FDG PET/CT-positive in more body sites than were noted clinically at first presentation and 160 patients had the same number of positive body sites. INTERPRETATION: 18F-FDG PET/CT scan has potential for further elucidating the spectrum of disease, pathogenesis of EPTB and monitoring the effects of treatment on active lesions over time, and requires longitudinal cohort studies, twinned with biopsy and molecular studies.

Sequential 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) scan findings in patients with extrapulmonary tuberculosis during the course of treatment-a prospective observational study.

BACKGROUND: Initial studies of tuberculosis (TB) in macaques and humans using 18F-FDG positron emission tomography (PET) imaging as a research tool suggest its usefulness in localising disease sites and as a clinical biomarker. Sequential serial scans in patients with extrapulmonary TB (EPTB) could inform on the value of PET-CT for monitoring response to treatment and defining cure. PATIENTS AND METHODS: HIV-negative adults with EPTB from eight sites across six countries had three 18F-FDG PET/CT scans: (i) within 2 weeks of enrolment, (ii) at 2 months into TB treatment and (iii) at end of ATT treatment. Scanning was performed according to the EANM guidelines. 18F-FDG PET/CT scans were performed 60 ± 10 min after intravenous injection of 2.5-5.0 MBq/kg of 18F-FDG. FINDINGS: One hundred and forty-seven patients with EPTB underwent 3 sequential scans. A progressive reduction over time of both the number of active sites and the uptake level (SUVmax) at these sites was seen. At the end of WHO recommended treatment, 53/147 (36.0%) patients had negative PET/CT scans, and 94/147 (63.9%) patients remained PET/CT positive, of which 12 patients had developed MDR TB. One died of brain tuberculoma. INTERPRETATION: Current 18F-FDG PET/CT imaging technology cannot be used clinically as a biomarker of treatment response, cure or for decision-making on when to stop EPTB treatment. PET/CT remains a research tool for TB and further development of PET/CT is required using new Mycobacterium tuberculosis-specific radiopharmaceuticals targeting high-density surface epitopes, gene targets or metabolic pathways.

Prompt and consistent improvement of coronary flow velocity reserve following successful recanalization of the coronary chronic total occlusion in patients with viable myocardium.

BACKGROUND: Coronary chronic total occlusion (CTO) is characterized by the presence of collateral blood vessels which can provide additional blood supply to CTO-artery dependent myocardium. Successful CTO recanalization is followed by significant decrease in collateral donor artery blood flow and collateral derecruitment, but data on coronary hemodynamic changes in relation to myocardial function are limited. We assessed changes in coronary flow velocity reserve (CFVR) by echocardiography in collateral donor and recanalized artery following successful opening of coronary CTO. METHODS: Our study enrolled 31 patients (60 ± 9 years; 22 male) with CTO and viable myocardium by SPECT scheduled for percutaneous coronary intervention (PCI). Non-invasive CFVR was measured in collateral donor artery before PCI, 24 h and 6 months post-PCI, and 24 h and 6 months in recanalized artery following successful PCI of CTO. RESULTS: Collateral donor artery showed significant increase in CFVR 24 h after CTO recanalization compared to pre-PCI values (2.30 ± 0.49 vs. 2.71 ± 0.45, p = 0.005), which remained unchanged after 6-months (2.68 ± 0.24). Baseline blood flow velocity of the collateral donor artery significantly decreased 24 h post-PCI compared to pre-PCI (0.28 ± 0.06 vs. 0.24 ± 0.04 m/s), and remained similar after 6 months, with no significant difference in maximum hyperemic blood flow velocity pre-PCI, 24 h and 6 months post-PCI. CFVR of the recanalized coronary artery 24 h post-PCI was 2.55 ± 0.35, and remained similar 6 months later (2.62 ± 0.26, p = NS). CONCLUSIONS: In patients with viable myocardium, prompt and significant CFVR increase in both recanalized and collateral donor artery, was observed within 24 h after successful recanalization of CTO artery, which maintained constant during the 6 months. TRIAL REGISTRATION: ClinicalTrials.gov (Number NCT04060615 ).

Impact of hybrid molecular imaging in retroperitoneal fibrosis: a systematic review.

The aim of this article was to critically assess the usefulness of hybrid molecular imaging (FDG PET/CT and FDG PET/MR) procedures in the evaluation of inflammatory activity in retroperitoneal fibrosis (RPF). A systematic review of the literature was performed using PubMed without timeline restriction and using the following keywords: retroperitoneal fibrosis, disease activity, diagnostic techniques, PET/CT, PET/MR. We evaluated full text articles written in the English language. Case reports, review articles or editorials and articles not in the field of interest of this review were excluded. Nine articles comprising a total of 186 patients met the inclusion criteria and were included and described in this systematic review. The new hybrid molecular imaging methods give promising results in the evaluation of the activity of the disease, quantification and prediction of therapeutic response and in tailoring medical therapy in RPF. FDG PET/CT can be a valuable tool in detecting disease activity, particularly in asymptomatic patients with RPF with acute phase reactant increase. Hybrid imaging can predict therapy response outcome and the best time for stent removal. Although PET/MR has potential advantage in small lesions and has reduced radiation exposure in comparison to PET/CT, PET quantification parameters have potentially higher diagnostic value over MR parameters in the evaluation of RPF. Acute phase reactants alone may not be reliable for the management and follow-up assessment of the disease. Hybrid imaging in RFP could be more comfortable, more accurate, with less radiation burden than different separate imaging studies acquired at different points in time.

Renal output efficiency and normalized residual activity examined by technetium-99m-DTPA renography have by far greater specificity to diagnose obstructive disease as compared to other conventional parameters of the renogram. First such study of output efficiency.

OBJECTIVE: The aim of this study was to assess the diagnostic ability of renal output efficiency (OE), normalized residual activity (NORA) and conventional interpretation of the diethylene triamine pentaacetic acid (99mTc-DTPA) diuretic renogram (CIR) in diagnosing urine flow obstruction. SUBJECTS AND METHODS: Group A consisted of 73 obstructed kidneys and Group B of 80 kidneys with dilated upper urinary tract. Forty eight kidneys were examined as the control Group C. A 40min acquisition with 240 of 10sec images was applied. Furosemide was administered after 20min (F+20). Post-void image was acquired at 50min. Output efficiency was calculated at 20min (OE20) and 20min after furosemide test (OE40) and NORA at 20min (NORA20) and on the post-micturition acquisition (NORAPM). RESULTS: Both the above parameters (OE40 and NORAPM) had high sensitivity (92% and 97%), specificity (99% for both) and accuracy (95% and 98%) in differentiating between obstructed and dilated unobstructed kidneys. The test of NORAPM correctly reclassified 40 out of 41 indeterminate or false positive results of the conventional interpretations of renograms (CIR) as obstructed (12 cases) or dilated (28 cases). Cut-off values for obstruction were <80% and ≥0.23 for OE40 and NORAPM, respectively. Compared to CIR, both parameters showed better specificity, especially NORAPM. CONCLUSION: Factors of OE40 and especially NORAPM of the renogram by 99mTc-DTPA were able to diagnose urine outflow obstruction better than CIR. Specifically, these factors well differentiated obstruction from urinary tract dilatation.

Diuresis renography and ultrasonography in children with antenatally detected hydronephrosis can support diagnoses and suggest related surgery treatment.

OBJECTIVE: Prenatal ultrasound (US) screening detects the hydronephrosis (HN)-dilatation of fetal renal collecting system in 1%-5% of all pregnancies. In most children, HN is detected by prenatal US screening between 18-20 gestational week. Pelvi- ureteric junction (PUJ) stenosis is the most common etiological factor of prenatal HN and requires postnatal follow-up. Diuresis renography plays important role in the follow-up by complementing morphological information obtained by US with the data about differential renal function (DRF) and drainage. We studied the association between ultrasound parameters and results of diuresis renography in first diagnosed PUJ stenosis and the predictive factors of pyeloplasty in order to evaluate the usefulness of diuresis renography in these children postnatally. PATIENTS AND METHODS: Children with antenatally detected HN attributed to presumed PUJ stenosis were investigated with mercapto-acetyltriglycine (MAG3) diuresis renography. Parents gave informed consent for the procedure. The inclusion criteria were: age up to 4 years, diagnosis of prenatal HN determined by US during pregnancy based on the antero-posterior diameter (APD) of renal pyelon and at least one post-natal US which confirmed diagnosis. Exclusion criteria were: APD of pyelon <10mm, previous surgical treatment of HN, vesicoureteral reflux excluded by micturating cystourethrography, and patients having any anomaly of the contralateral kidney. Sixty two patients 43 boys, 19 girls, median age 16 months were selected. They were divided into three groups based on the size of pyelon, three groups based on the calyceal size and two groups according to thickness of parenchyma. Renography was performed for 24 minutes after the iv. application of 99mTc MAG3, 144 ten-sec images were applied. Furosemide was administered after 2 min. (F+2). Post-void static images were acquired at 60min. The non-commercial software developed by International Atomic Energy Agency was applied to process the studies. The criteria for pathological findings (poor or no drainage) were the renographic curve maintaining a plateau, Normalized Residual Activity (NORA) at 20. min.>1.62, Output efficiency (OE) at 20. min.<71%, postmicturating NORA >0.11. The DRF was considered normal within the range of 45%-55%. RESULTS: Good drainage had 74% of children, partial drainage 11%, and poor 15%. There was a clear association between the size of pyelon, calyces, parenchyma thickness and drainage. There was also a clear association between the calyceal size, parenchyma thickness and DRF. Differential renal function was <45% in 18% of children. A relation between the type of drainage and DRF was not determined. Thus, 66.7% of those with poor drainage had preserved DRF. Seven out of nine children with poor drainage underwent pyeloplasty. The threshold for pyeloplasty was the pyelon of 18mm and calyces of 10mm. The model of the multivariate logistic regression which included ultrasound parameters (APD of pyelon, calyces size and parenchymal thickness), drainage and DRF, which were significant predictors in univariate analysis, showed that only drainage was an independent predictor for the need of pyeloplasty. CONCLUSION: Antero-posterior diameter of the pyelon <15mm indicates a favorable course of congenital HN in most children. Pattern of drainage obtained by diuresis renography was the only independent predictor for the need of pyeloplasty.

The detection of endocarditis, post implantation grafts, arteritis and other related disorders by 18F-FDG PET/CT.

INTRODUCTION: Positron emission tomography with computed tomography (18F-FDG PET/CT) is a nuclear medicine diagnostic method which, unlike other technological modalities that asses anatomical features, detects increased glucose metabolism inside the cells, thus is very helpful in diagnosing cardiovascular infection and inflammation and also in therapy planning. AIM: Aim of this study was to assess the significance of 18F-FDG PET/CT in detection of an active disease in patients with infection and inflammation of cardiovascular system. MATERIAL AND METHODS: In this cohort retrospective study 73 cardiovascular patients (56.9±15.3 years; 33 male and 40 female) with persistent symptoms of inflammatory syndrome were referred to 18F-FDG PET/CT in order to evaluate active disease. Biochemical blood analyses (erytrocite sedimentation, CRP, leukocytic formula), CT, MRI, ultrasound were performed in all the patients. Out of 73 patients, 7 had a second 18F-FDG PET/CT examination (62.1±12.3 years; 6 men and 1 woman) with a previous pathological PET/CT finding after which the therapy was changed. The degree of metabolic activity was analyzed visually and quantitatively using the maximal standardized uptake value (SUVmax). 18F-FDG PET/CT findings were considered positive in case of higher focal glucose accumulation in projection of heart and diffuse uptake in blood vessels' wall than accumulation in surrounding tissue and liver. RESULTS: Vasculitis was diagnosed in 36 patients (49,3%), endocarditis in 23 (31,5%) and graft inflammation in 14 (19,2%). The results were compared to the gold standard, biopsy of the blood vessel and histopathological verification during surgical treatment, or clinical follow up. Forty nine patients with the sights of an increased FDG uptake were considered true positive (TP) (SUVmax5.7±2.9). In 21 patients 18F-FDG uptake was physiological and they were considered true negative (ТN). Two who used corticosteroid therapy which decreases inflammation, were false negative (FN), and only 1 false positive (FP) finding in the region of recent iatrogenic vein injury. Sensitivity of this method was 96.08±, specificity 95.45±, positive predictive value 98.0±, negative predictive value 91.3± and accuracy 95.89±. CONCLUSION: Our results indicate that 18F-FDG PET/CT could be useful diagnostic method for the detection of sights of metabolically active disease in patients with persistent symptoms of infection and inflammation of cardiovascular system, as well as in monitoring therapy response.

Diagnosis of Raynaud's phenomenon by 99mTc-pertechnetate hand perfusion scintigraphy: a pilot study.

We assess the usefulness of 99mTc-pertechnetate hand perfusion scintigraphy in patients with Raynaud's phenomenon (RP). The study population consisted of 18 patients with primary RP, 25 patients with secondary RP within systemic sclerosis (SSc), and ten healthy individuals. Gamma camera dynamic first-pass study during the first 60 s and a static scintigraphy after 5 min were recorded following a bolus injection of 99mTc-pertechnetate via a cubital vein. Regions of interest were drawn on the summed images around the fingers and the palmar region. The fingers-to-palm ratios were then calculated. The mean fingers-to-palm ratio for dynamic study (blood flow) was 0.58 ± 0.19 for the healthy group, 0.45 ± 0.18 for the primary RP, and 0.43 ± 0.21 for the SSc patients. The mean fingers-to-palm ratio for static study (blood pool) was 0.44 ± 0.06 for the healthy group, 0.42 ± 0.06 for the primary RP, and 0.36 ± 0.07 for the SSc patients. Analysis of variance showed these differences to be significant (p = 0.039 from blood flow and p = 0.004 from blood pool). The receiver operating characteristic curve showed sensitivity of 80% and a specificity of 60% when using cutoff values of 0.40 for blood flow and sensitivity of 79% and a specificity of 70% when using cutoff values of 0.37 for blood pool. Our method is able to differentiate between patients with normal and those with abnormal microcirculation of the hands. Dynamic study separates the healthy subjects from patients with RP, while static study separates primary from secondary RP.

Validation of numerical outputs of IAEA software by the analysis of diuretic nephrogram in children with antenatally detected hydronephrosis.

UNLABELLED: Diuretic nephrogram is important diagnostic tool in the postnatal follow-up of asymptomatic antenatally detected hydronephrosis (HN). In the last decades, two quantitative indices of renal excretion, output efficiency and the residual kidney counts normalized to the 1-2min counts (normalized residual activity, NORA) have been proposed, that enhance the accuracy of technique to detect kidneys with obstruction. Unfortunately, in many nuclear medicine departments in developing countries the obsolete computer systems do not give the opportunity of sophisticated analysis of nephrogram. Almost a decade ago, the Nuclear Medicine Section of the International Atomic Energy Agency (IAEA) has developed non-commercial software for nephrogram processing on a simple p-computer, which allows access to the developments in this field. However, till now, the software has not been widely implemented in the nuclear medicine institutions in developing countries. Furthermore, the accuracy of numerical outputs of the software has not been assessed in comparison with commercial software. The aims of this study in children were: a) to calculate, by means of the International Atomic Energy Agency (IAEA) software, the values of the technetium-99m mercapto-acetyl-triglycine ((99m)Tc MAG3) parameters in three categories of kidneys: normal kidneys, obstructed kidneys and hypotonic unobstructed kidneys and b) to assess the accuracy of the obtained numerical parameters by comparing with the values published by other authors. Investigation was carried out on a sample of 62 children: 43 boys and 19 girls (median age: 16 months) with antenatally detected HN attributed to pelviureteric junction (PUJ) stenosis. Neither of kidneys had undergone pyeloplasty prior to our investigation. 130 nephrogram curves were analyzed. 22-minutes acquisition with 132 10sec images was applied. Furosemide was administered after 2min (F+2). Post-void static image was acquired at 60min. Two observers analyzed each study and classified kidneys into three categories. Group 1: 84 kidneys contralateral to hydronephrotic kidney, without structural abnormality on previous diagnostics; Group 2: 30 hypotonic non-obstructed kidneys; Group 3: 16 obstructed kidneys. Parameters analyzed were: output efficiency (OE), residual kidney counts at 20min normalized to the 1-2min counts (NORA20) and residual kidney counts on post-micturition acquisition normalized to the 1-2min counts (NORAPM). Results were presented as mean±SD. For group 1 they were: OE: 95±1.5%; NORA20: 0.25±0.06; NORAPM: 0.02±0.007. Results for group 2 were: OE: 87±7.8%; NORA20: 0.57±0.19; NORAPM: 0.03±0.02. For group 3: OE: 56±9.6%; NORA20: 2.16±0.33; NORAPM: 0.27±0.13. Linear regression analysis showed significant inverse linear correlation between NORA20 and ROE20 (R=-0.982; y=99.6-21.1x) at 0.01 level. ROC analysis revealed cutoff values of predicting obstruction at 71%, 1.62 and 0.11 for OE, NORA20 and NORAPM, respectively. CONCLUSION: We have calculated in children by means of the IAEA software the values of three advanced parameters of the (99m)Tc MAG3 F+2 diuresis nephrogram for normal kidneys, hypotonic non-obstructed and obstructed kidneys. The overall results provided evidence of excellent agreement of obtained results with previously reported values of the quantitative parameters of renal washout. The parameters of IAEA software has been shown to be reliable in assessing kidney drainage. The nuclear medicine section of the IAEA should be encouraged to produce final version of the software and to release it through IAEA Web site.

The diagnostic performance and added value of (18)F-FDG PET/CT in the detection of liver metastases in recurrent colorectal carcinoma patients.

OBJECTIVE: The aim of this study was to assess the value of (18)F-fluorodeoxyglucose ((18)F-FDG) PET/CT in detection of liver metastases in patients with suspected recurrent colorectal carcinoma, as well as to compare diagnostic performance of (18)F-FDG PET/CT with conventional imaging methods (MDCT). SUBJECTS AND METHODS: This study included 73 patients with resected primary colorectal adenocarcinoma referred for (18)F-FDG PET/CT to the National PET Center, at the Clinical Center of Serbia, Belgrade, from January 2010 to May 2013, with suspicion of recurrence. The patients underwent (18)F-FDG PET/CT examination on a 64-slice hybrid PET/CT scanner (Biograph, TruePoint64, Siemens Medical Solutions, Inc. USA). Prior to (18)F-FDG PET/CT all patients underwent contrast-enhanced MDCT. Findings of (18)F-FDG PET/CT and MDCT were compared to findings of subsequent histopathological examinations or with results of clinical and imaging follow-up over at least six months. Final diagnosis of liver metastases of colorectal cancer was made either by histopathological examination of specimen after biopsy or surgery, or based on clinical, laboratory and imaging evaluation during first six months after PET/CT scan. RESULTS: In detection of liver metastases (18)F-FDG PET/CT showed sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 83.3%, 95.3%, 92.6%, 89.1% and 90.4%, respectively. In addition, MDCT showed sensitivity, specificity, positive predictive value, negative predictive value and accuracy in detection of liver metastases of 60%, 88.4%, 78.3%, 76% and 76.7%, respectively. There was significant difference in sensitivity (83.3% vs 60%; P=0.045) between these two methods. In addition, significant difference was observed in accuracy between PET/CT and MDCT (90.4% vs 76.7%; P=0.016). The higher specificity in visualization of liver metastases was also achieved by (18)F-FDG PET/CT compared to MDCT (95.3% vs 88.4%), but this difference was not significant (P=0.37). CONCLUSION: (18)F-FDG PET/CT was highly sensitive, specific and accurate method in detection of liver metastases in patients with suspected recurrent colorectal carcinoma in our study. This hybrid imaging showed superior diagnostic performance in evaluation of suspected colorectal cancer liver metastases compared to conventional imaging.

Can (18)F-FDG PET/CT scan change treatment planning and be prognostic in recurrent colorectal carcinoma? A prospective and follow-up study.

OBJECTIVE: To prospectively study whether in patients with resected primary colorectal cancer fluorine- 18-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) examination could diagnose the stage, specify treatment procedure and be prognostic. SUBJECTS AND METHODS: This prospective study included 75 patients with resected primary colorectal adenocarcinoma referred for (18)F-FDG PET/CT to the National PET Center, at the Clinical Center of Serbia, Belgrade, from January 2010 to May 2013. Findings of (18)F-FDG PET/CT were compared to findings of subsequent histopathological examinations or with results of clinical and imaging follow-up. Patients were followed after PET/CT examination for a mean follow-up time of 16.7±5.9 months. RESULTS: In the detection of recurrent disease (18)F-FDG PET/CT showed overall sensitivity, specificity, PPV, NPV and accuracy of 96.6%, 82.4%, 94.9%, 87.5% and 93.3%, respectively. In the detection of stages I and II sensitivity, specificity and accuracy of (18)F-FDG PET/CT were: 88%, 96.6% and 94.7%, respectively, and in the detection of stages III and IV sensitivity, specificity and accuracy were 94.9%, 87.5% and 93.3%, respectively. These findings prevented or changed intended surgical treatment in 12/32 cases. Univariate and multivariate Cox proportional regression analyses revealed that metastatic recurrence (stages III and IV) was the only and independent prognostic factor of disease progression during follow-up (P=0.012 and P=0.023, respectively). Although, survival seemed better in patients with local recurrence compared to metastatic recurrent disease, this difference did not reach significance (Log-rank test; P=0.324). In addition, progression-free survival time was significantly longer in patients in whom (18)F-FDG PET/CT scan led to treatment changes (Log-rank test; P=0.037). CONCLUSION: (18)F-FDG PET/CT was sensitive and accurate for the detection and staging of local and metastatic recurrent colorectal carcinoma, with higher specificity in the detection of local recurrences. The (18)F-FDG PET/CT scan induced treatment changes in 30/75 patients, including 12/32 patients in which surgical treatment was previously planned, and progression free survival time was significantly longer in these patients.

Acute insulin resistance in ST-segment elevation myocardial infarction in non-diabetic patients is associated with incomplete myocardial reperfusion and impaired coronary microcirculatory function.

BACKGROUND: Insulin resistance (IR) assessed by the Homeostatic Model Assessment (HOMA) index in the acute phase of myocardial infarction in non-diabetic patients was recently established as an independent predictor of intrahospital mortality. In this study we postulated that acute IR is a dynamic phenomenon associated with the development of myocardial and microvascular injury and larger final infarct size in patients with ST-segment elevation myocardial infarction (STEMI) treated by primary percutaneous coronary intervention (pPCI). METHODS: In 104 consecutive patients with the first anterior STEMI without diabetes, the HOMA index was determined on the 2nd and 7th day after pPCI. Worst-lead residual ST-segment elevation (ST-E) on postprocedural ECG, coronary flow reserve (CFR) determined by transthoracic Doppler echocardiography on the 2nd day after pPCI and fixed perfusion defect on single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI) determined six weeks after pPCI were analyzed according to HOMA indices. RESULTS: IR was present in 55 % and 58 % of patients on day 2 and day 7, respectively. Incomplete post-procedural ST-E resolution was more frequent in patients with IR compared to patients without IR, both on day 2 (p = 0.001) and day 7 (p < 0.001). The HOMA index on day 7 correlated with SPECT-MPI perfusion defect (r = 0.331), whereas both HOMA indices correlated well with CFR (r = -0.331 to -0.386) (p < 0.01 for all). In multivariable backward logistic regression analysis adjusted for significant univariate predictors and potential confounding variables, IR on day 2 was an independent predictor of residual ST-E ≥ 2 mm (OR 11.70, 95% CI 2.46-55.51, p = 0.002) and CFR < 2 (OR = 5.98, 95% CI 1.88-19.03, p = 0.002), whereas IR on day 7 was an independent predictor of SPECT-MPI perfusion defect > 20% (OR 11.37, 95% CI 1.34-96.21, p = 0.026). CONCLUSION: IR assessed by the HOMA index during the acute phase of the first anterior STEMI in patients without diabetes treated by pPCI is independently associated with poorer myocardial reperfusion, impaired coronary microcirculatory function and potentially with larger final infarct size.

Detection of post-exercise stunning by early gated SPECT myocardial perfusion imaging: results from the IAEA multi-center study.

BACKGROUND: Transient post-ischemic LV dysfunction due to myocardial stunning in patients with coronary artery disease can be missed by conventional gated SPECT (GSPECT) acquisitions. The aim of this IAEA-sponsored multi-center study was to determine whether early post-exercise imaging is more likely to detect stunning than conventional without adversely affecting image quality or perfusion information. METHODS AND RESULTS: Patients undergoing exercise/rest GSPECT were enrolled in this international multicenter study. Post-exercise studies were acquired at 15 ± 5 minutes after radiotracer injection (Stress-1) and repeated at 60 ± 15 minutes (Stress-2). Rest studies (R) were acquired at 60 minutes post injection. A core laboratory quantitatively assessed perfusion pattern and LV blinded to the acquisition time. Ischemia was defined as summed stress score (SDS) ≥4, and stunning was defined as the difference between rest and post-stress LVEF (Δ-LVEF). In the 229 patients enrolled into the study, both image quality and perfusion information were similar between Stress-1 and Stress-2. Post-stress LVEF was associated with both ischemia and time of acquisition, with a significant correlation between SDS and Δ-LVEF, which was stronger at Stress-1 than Stress-2 in the ischemic compared to the non-ischemic population (r = 0.23 vs 0.08, P = 0.10). CONCLUSIONS: Early post-exercise imaging is feasible, and can potentially improve the detection of post-ischemic stunning without compromising image quality and perfusion data.

Correlates of markers of dyssynchrony in patients with STEMI and multivessel disease: an analysis from the IAEA SPECT STEMI trial.

BACKGROUND: In this substudy of the Value of Gated-SPECT MPI for Ischemia- Guided PCI of non-culprit vessels in STEMI Patients with Multi vessel Disease after primary PCI trial on the value of myocardial perfusion imaging (MPI) for ischemia-guided percutaneous coronary intervention (PCI) of nonculprit vessels in patients with ST-segment-elevation myocardial infarction (STEMI) and multivessel disease after primary PCI we aim to assess if infarct size affects conventional measures of dyssynchrony at rest. Additionally, we explore if there is an independent correlation of stress-inducible ischemia with dyssynchrony at rest. METHODS: The 48 patients with imaging at randomization were analyzed. Gated-single-photon emission computed tomography (SPECT) MPI with vasodilator stress and technetium-99m-labeled tracers was performed. The phase histogram bandwidth (HBW), phase SD, and entropy were obtained with the QGS software. Correlation between dyssynchrony at rest and infarct size and inducible ischemia was performed using the Spearman test. RESULTS: According to normal database limits dyssynchrony parameters at rest were abnormal for men. In women only HBW was abnormal. Correlation between the summed rest score with dyssynchrony was significant only for entropy (P = 0.035). No correlation was observed for dyssynchrony and stress-induced ischemia. CONCLUSION: Entropy, as a measure of dyssynchrony, has potential in the assessment of patients with STEMI and multivessel disease after primary PCI. Smaller residual myocardial scars in PCI-reperfused patients with STEMI may contribute to the lack of correlation between dyssynchrony at rest and infarct size and stress-induced ischemia, respectively.

Correlation of Non-Invasive Transthoracic Doppler Echocardiography with Invasive Doppler Wire-Derived Coronary Flow Reserve and Their Impact on Infarct Size in Patients with ST-Segment Elevation Myocardial Infarction Treated with Primary Percutaneous Coronary Intervention.

Background: Coronary microvascular dysfunction is associated with adverse prognosis after ST-segment elevation myocardial infarction (STEMI). We aimed to compare the invasive, Doppler wire-based coronary flow reserve (CFR) with the non-invasive transthoracic Doppler echocardiography (TTDE)-derived CFR, and their ability to predict infarct size. Methods: We included 36 patients with invasive Doppler wire assessment on days 3-7 after STEMI treated with primary percutaneous coronary intervention (PCI), of which TTDE-derived CFR was measured in 47 vessels (29 patients) within 6 h of the invasive Doppler. Infarct size was assessed by cardiac magnetic resonance at a median of 8 months. Results: The correlation between invasive and non-invasive CFR was modest in the overall cohort (rho 0.400, p = 0.005). It improved when only measurements in the LAD artery were considered (rho 0.554, p = 0.002), with no significant correlation in the RCA artery (rho -0.190, p = 0.435). Both invasive (AUC 0.888) and non-invasive (AUC 0.868) CFR, measured in the recanalized culprit artery, showed a good ability to predict infarct sizes ≥18% of the left ventricular mass, with the optimal cut off values of 1.85 and 1.80, respectively. Conclusions: In patients with STEMI, TTDE- and Doppler wire-derived CFR exhibit significant correlation, when measured in the LAD artery, and both have a similarly strong association with the final infarct size.