Post-treatment FDG PET/CT predicts progression-free survival in young patients with small round blue cell tumors: Ewing sarcoma and PNET.

PURPOSE: To determine if post-treatment F-18 FDG PET/CT results (overall positive findings, specific localizations) are independent predictors of disease progression in young patients with Ewing sarcoma and Primitive neuroectodermal tumor. METHOD: A consecutive sample of 48 patients (age 14 ±â€¯5 years, 32 male) was referred to F-18 FDG PET/CT for the suspected progression of Ewing sarcoma (39 patients) and Primitive neuroectodermal tumor (PNET) (9 patients) and followed-up clinically for 4.3 ±â€¯2.3 years after F-18 FDG PET/CT (range 1-8 years). The diagnostic value of F-18 FDG PET/CT was determined in comparison to the biopsy. Kaplan-Meier analysis was used to compare progression-free survival between the groups with positive and negative F-18 FDG PET/CT findings. Variables included in the Cox regression for predicting the progression-free survival were sex, age, F-18 FDG PET/CT findings, MDCT findings, and MR ratio. RESULTS: F-18 FDG PET/CT findings were positive in 32 (67 %) patients (sensitivity 93.7 %, specificity 87.5 %, accuracy 91.7 %) with an average SUVmax of 5.8 ±â€¯3.2 (95 % CI 4.8-7.1). The progression-free survival was significantly lower (p = 0.001) in patients with positive F-18 FDG PET/CT findings (median 28 months) and when recurrence was located in bones, soft tissues, and muscles (p = 0.02, median 21 months). The significant predictors of the disease progression were the overall positive F-18 FDG PET/CT findings (HR 8.36, p = 0.004) and, specifically, the local recurrence in the bone with infiltration of soft tissue/muscles (HR 4.08, p = 0.003). CONCLUSION: Post-treatment F-18 FDG PET/CT findings are useful for predicting the progression of Ewing sarcoma and PNET and should be included in the clinical monitoring of these patients.

Interobserver reproducibility of mercaptoacetyltriglicine renography in children and adults with suspected obstruction: parameters of drainage and function calculated by International Atomic Energy Agency software.

OBJECTIVE: The aim of this study was to estimate interobserver reproducibility of Tc-99m mercaptoacetyltriglycine renography in children and adults by assessing the parameters of the International Atomic Energy Agency (IAEA) software for the analysis of dynamic renal studies. METHODS: The renograms of 65 children and 65 adults covered a wide age range, different quality of drainage, overall function and differential renal function (DRF). Three observers were processing parameters of the IAEA software. Normalized residual activity at 20 min (NORA20), NORA on the postmicturition acquisition (NORApm), PM to maximum renal count ratio (PM/max), output efficiency at 20 min (OE20), OE 20 min after diuretic stimulation (OEF + 20), whole kidney mean transit time (MTT) and DRF by integral and Rutland-Patlak were calculated by observers. RESULTS: The overall agreement between three observers was almost perfect [the average intraclass correlation coefficient (ICC) above 0.99] in children and adults, with no significant difference between the parameters of renal drainage, transit and DRF. ICCs for all parameters were higher than 0.980 in children under 12 months, even slightly greater for PM/max and OEF+20. In children with poor/incomplete drainage and DRF below 40%, ICCs were above 0.98. In the subgroup of adults with impaired overall tubular extraction rate, level of reproducibility was almost perfect. Slightly lower but still insignificant values of ICC were presented in adults with poor/incomplete drainage. CONCLUSION: Our results indicate an excellent interobserver reproducibility for all quantitative parameters of IAEA software in both pediatric and adult patients.

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.

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.

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.

Validation of IAEA software package for the analysis of scintigraphic renal dynamic studies: parameters of renal transit in children with renal pelvic dilatation.

PURPOSE: The objectives of the study were to use the International Atomic Energy Agency (IAEA) software package for the analysis of scintigraphic renal dynamic studies to obtain values of curve parameters and excretory parameters in children with hydronephrosis and to validate the reliability of these numerical outputs by comparing with values established by consensus reports. PATIENTS AND METHODS: Fifty children with hydronephrosis (median age, 16 months; 30 boys, 20 girls; 99 kidneys) underwent Tc-MAG3 diuresis renography. Studies were analyzed by 2 observers, and according to the assessment of images, renograms, and differential function, kidneys were classified as normal (42, kidneys contralateral to hydronephrotic kidney), hypotonic unobstructed (49), and obstructed (8). The IAEA software was applied to each renogram. The parameters analyzed were as follows: normalized residual activity at 20 minutes (NORA 20) and on postmicturition (PM) acquisition, output efficiency at 20 minute (OE 20), PM to maximum renal count ratio (PM/max), and mean transit time (MTT). RESULTS: Mean values for normal, hypotonic unobstructed, and obstructed kidneys were as follows: NORA 20: 0.25, 0.57, and 2.16; OE 20 (%): 94.5, 87, and 57; normalized residual activity on PM acquisition: 0.02, 0.03, and 0.27; PM/max: 0.01, 0.02, and 0.13; and MTT (minutes): 1.9, 3.5, and 8.9, respectively. Difference between obstruction/dilatation and normal/dilatation was significant (P < 0.0001), as well as the correlation between NORA 20/OE 20 (R = -0.982). Cutoff values to predict obstruction were as follows: NORA 20, 1.6; OE 20, 73%; NORA PM, 0.11; PM/max, 0.06; and MTT, 8.23 minutes. CONCLUSIONS: The IAEA software package gives reliable values of numerical parameters of renal excretion. The use of the software improves diagnostic accuracy of diuresis renography in children.

Diagnostic and prognostic value of gated SPECT MIBI early post-stress imaging in patients with intermediate Duke Treadmill Score.

PURPOSE OF THE REPORT: The aims of this study were to compare perfusion and functional parameters between early (ES) and standard (SS) post-stress gated SPECT MIBI, to validate ES against coronary angiography, and to determine whether ES parameters can predict future cardiac events. PATIENTS AND METHODS: The sample included 63 patients with normal or mildly impaired left ventricular function and intermediate Duke Treadmill Score. They underwent a 2-day stress-rest gated SPECT MIBI with the post-stress data acquired at 15 minutes (ES) and 60 minutes (SS) after i.v. injection of 740 MBq of 99mTc-MIBI. The ES findings were compared to SS and against coronary angiography to determine their sensitivity/specificity for detecting >70% stenosis. The information about new-onset cardiac events was collected 26 ± 6 months later. RESULTS: Perfusion parameters did not significantly differ between ES and SS. Ejection fraction was significantly lower and regional wall motion abnormalities were significantly higher on ES than SS. The corresponding perfusion and functional parameters were strongly related (linear regression slope 0.65-1.00, intercept -0.36-8.5, R2 0.98-0.75). ES parameters had high sensitivity (96%) and specificity (83%) for detecting >70% stenosis. Lower early stress than rest EF (>5%), higher early stress than rest EDV, and early SSS >8 emerged as significant predictors of new-onset cardiac events. CONCLUSIONS: Early post-stress gated SPECT MIBI yields comparable perfusion and functional parameters as the standard post-stress protocol. ES parameters are useful for detecting the existing coronary disease and for predicting future cardiac events. ES protocol is recommended for improving patient compliance and efficiency of nuclear cardiology services.

Responsiveness of FDG PET/CT to treatment of patients with active chronic sarcoidosis.

PURPOSE: This study aimed to compare baseline to follow-up 18F-FDG PET/CT findings after treatment for active chronic sarcoidosis and to correlate changes on 18F-FDG PET/CT with changes in clinical status. PATIENTS AND METHODS: The sample included 66 patients with chronic sarcoidosis and evidence of active inflammation on baseline F-FDG PET/CT for which they received therapy. Of these 66 patients, 30 returned for the follow-up 18F-FDG PET/CT after 12 (5) months to evaluate response to treatment. They were also asked to indicate changes in clinical status. Baseline characteristics of patients who did and did not return for the follow-up were compared to assess selection bias. RESULTS: SUVmax was significantly decreased at the follow-up compared with baseline 18F-FDG PET/CT (8.46 [3.52] vs 4.90 [0.96]; P = 0.006), primarily in the mediastinum. Inflammatory activity appeared absent in 9 patients, decreased in 12 patients, and increased in 9 patients, with the corresponding changes in SUVmax of -80%, -41%, and +54%, respectively. The changes on 18F-FDG PET/CT were in agreement with self-perceived changes in clinical symptoms (P = 0.019). The angiotensin-converting enzyme at the follow-up was not significantly different from baseline (49.80 [19.25] vs 46.35 [25.58], P = 0.522). There was no difference in baseline characteristics of patients who did and did not return for the follow-up. CONCLUSIONS: 18F-FDG PET/CT is able to detect clinically meaningful changes in magnitude and extent of inflammatory activity in patients receiving treatment for active chronic sarcoidosis. Thus, 18F-FDG PET/CT is a valuable adjunct to clinical evaluation for monitoring the response to treatment in these patients.

Dopamine transporter imaging (123)I-FP-CIT (DaTSCAN) SPET in differential diagnosis of dopa-responsive dystonia and young-onset Parkinson's disease.

Dopa-responsive dystonia (DRD) is a genetic disorder characterized by childhood onset dystonia, dominant inheritance, diurnal symptoms fluctuation and positive levodopa response. Adult-onset DRD is frequently combined with parkinsonism and can be mistaken with young onset Parkinson's disease (YOPD). Both conditions are caused by dopamine deficiency, due to nigral cells' loss in YOPD, and due to enzymatic defects in dopamine synthesis in DRD. Single photon emission tomography (SPET) with (123)I-N--fluoropropyl-2b-carbomethoxy-3b-(4-iodophenyl) nortropane ((123)I-FP-CIT)-DaTSCAN is a sensitive neuroimaging method for the assessment of nigrostriatal dopaminergic system integrity and degeneration. Our aim was to evaluate the usefulness of (123)I-FP-CIT( DaTSCAN) SPET in the differential diagnosis of DRD and YOPD in clinical practice. Brain SPET with (123)I-FP-CIT was performed in 13 patients (7 males, 6 females), age 20-58 years, with mean age of onset of their disease, 29 years, eleven patients with early onset parkinsonian symptoms and 2 with genetically proved DRD. The images were evaluated by visual and semiquantitative analyses (ROI). The ratio of specific-striatal to non specific-occipital binding was calculated. Ten out of 11 patients with YOPD had decreased accumulation of DaTSCAN in striatum, especially in putamen, that is typical findings for Parkinson's disease. In three patients DaTSCAN was normal with symmetric tracer uptake in both striata, caudate nucleus and putamen and the diagnosis of DRD was suspected. Two patients with initial dystonic symptoms and genetically proved DRD had normal DaTSCAN. In one patient after normal DaTSCAN findings the initial diagnosis of YOPD was changed to the diagnosis of DRD. Region of interest (ROI) analyses have shown significantly lower(123)I-FP-CIT binding ratios in YOPD than in DRD in all 3 regions of interest: striatum (1.95±0.32) vs (2.76±0.10) P<0.001, putamen (1.76±0.25) vs (2.84±0.14) P<0.0001 and caudate nucleus (2.37±0.51) vs (3.27±0.14) P<0.01. In conclusion, our results indicate that DaTSCAN is an objective neuroimaging method able to distinguisch neurodegenerative disease YOPD from DRD and clarify a clinical dilemma, which is important for the treatment, prognosis and genetic counseling of patients and their families.

The utility of two somatostatin analog radiopharmaceuticals in assessment of radiologically indeterminate pulmonary lesions.

PURPOSE: The aim of our study was to assess diagnostic accuracy of Tc-99m depreotide and Tc-99m-EDDA/HYNIC-TOC scintigraphy for evaluation of pulmonary lesions that appeared ambiguous on computed tomography (CT). MATERIAL AND METHODS: Forty-nine consecutive patients (37 men and 12 women; mean age, 60 ± 11 years) with 60 pulmonary lesions on chest radiography and CT were referred for nuclear imaging. They were prospectively allocated to undergo whole-body scintigraphy (WBS) and single photon emission computed tomography (SPECT) using either Tc-99m depreotide (26 patients, group 1) or Tc-99m-EDDA/HYNIC-TOC imaging (23 patients, group 2). Histologic findings after tissue biopsy served as a gold standard for determining diagnostic accuracy of the 2 somatostatin analogs. Visual assessment was complemented by semiquantitative analysis based on target to background ratio. RESULTS: Among the 32 pulmonary lesions scanned with Tc-99m depreotide, focal uptake was increased in 22 of 25 malignancies, whereas no uptake was found in 6 of 7 benign lesions (88% sensitivity, 85% specificity, and 88% accuracy) on both WBS and SPECT. Imaging of 28 pulmonary lesions with Tc-99m-EDDA/HYNIC-TOC had a similar diagnostic yield (sensitivity 87%, specificity 84%, and accuracy 86%). Overall, target to background ratios were higher on SPECT than WBS but not significantly different between groups 1 and 2 (SPECT 2.72 ± 0.70 vs. 2.71 ± 0.50, WBS 1.61 ± 0.32 vs. 1.62 ± 0.28, respectively). CONCLUSION: This study demonstrates that Tc-99m depreotide and Tc-99m-EDDA/HYNIC-TOC have similar diagnostic value for characterizing pulmonary lesions that appear ambiguous on CT.

The diagnostic role of gated myocardial perfusion imaging and radionuclide ventriculography in severe congenital heart disease.

Several techniques have been applied for the assessment of severe congenital heart diseases (SCHD) including echocardiography, cardiac catheterization with angiocardiography, and more recently, cardiovascular multi detector tomography and magnetic resonance imaging (MRI). The value of gated single photon emission tomography (GSPET) myocardial perfusion imaging (MPI) and radionuclide ventriculography (RNV) for evaluating myocardial ischemia, tissue viability, and left ventricular function in SCHD is less apparent. The risk of radiation exposure is greatest in the youngest patients. Both, GSPET MPI and RNV seem to be underutilized in pediatric clinical practice due to increased radiation exposure. We have reviewed basic and specific technical and diagnostic aspects, as well as specific clinical indications of GSPET MPI and RNV in children with SCHD in comparison with other cardiology methods. Some of our own tests are also presented where they apply. In conclusion, GSPET MPI and RNV can provide clinical relevant information of functional significance of SCHD in pediatric patients especially when the other cardiology methods are indeterminate. With regard to radiation exposure appropriate patient selection and recommendations for reduction of radiation exposure are of great importance.

Possible role of the scintigraphic estimation of the relative liver perfusion in the diagnosis and therapy of liver carcinomas.

BACKGROUND: The aim of the study is evaluation of the possible role of the scintigraphic estimation of the relative liver perfusion in diagnosis and the choice of treatment of liver carcinomas. MATERIAL AND METHODS: Hepatic perfusion index was obtained by dynamic scintigraphy in 126 patients. RESULTS: In the control group values did not differ from the value in the patients with benign tumors (p > 0.05). However, in hepatocellular carcinoma and liver metastases of different tumors, HPI values were significantly decreased in comparison to controls and benign tumors (p < 0.01), but they didn't differ between themselves (p > 0.05). The values were especially low in the patients with malignant diseases in the liver accosciated with vascular disturbances in the portal system. CONCLUSION: HRA could be easily done during the different conventional nuclear medicine methods. It can be an useful method for the assessment of different degrees of hemodynamic alterations in portal system, for differential diagnosis of benign and malignant liver tumors, as well as for assessment of the liver tissue and tumor perfusion, which might be helpful in the decision making for the undertaking of intraarterial (radionuclide, chemotherapy etc.) therapy.

Investigation of blood perfusion and metabolic activity of brain tumours in adults by using 99mTc-methoxyisobutylisonitrile.

OBJECTIVES: (i) To examine blood perfusion and metabolic activity of various brain tumours using radionuclide cerebral angiography (RCA) and single-photon emission tomography (SPET) after a single dose of Tc-methoxyisobutylisonitrile (MIBI). (ii) To examine if the inclusion of RCA can improve insight into the relative contribution of tumour perfusion to the uptake of MIBI shown by SPET, and to improve evaluation of tumour biology. (iii) To determine the value and the roles of MIBI in the management of brain tumour patients. METHODS: Fifty adult patients (38 male, 12 female) with a total of 56 intracranial space-occupying lesions have been included prospectively, 37 of which were newly diagnosed and the remaining with signs of recurrence/rest of earlier resected and irradiated brain tumours. The control group consisted of nine volunteers with no evidence of organic cerebral disease. Scintigraphic examination consisted of a dynamic first-pass study lasting 60 s (3 s/frame) and two SPET studies (60 projections each, 25 s/projection), starting 15 min and 2 h after intravenous injection of MIBI. Regions of interest of the tumour and normal brain tissue were drawn on RCA and both early and delayed SPET slices. The following tumour/brain activity ratios have been calculated: (i) tumour perfusion index (P); (ii) early uptake index (E); (iii) delayed uptake index (D); and(iv) retention index (R). Analogous indices have been calculated from the same examinations performed in controls, reflecting maximal physiologic regional variations of perfusion and uptake in brain tissue. RESULTS: Mean P of various brain tumours (low-grade gliomas 0.98, anaplastic gliomas 1.14, glioblastoma multiforme 1.20, metastases 1.09, lymphomas 1.08) differ little from each other and do not exceed maximal physiologic regional variations of cerebral perfusion (1.33), with the exception of meningioma (1.87, F=2.83, P=0.015). The receiver operating characteristics curve analysis of P showed that for the cut-off value of 1.45 the sensitivity for distinguishing meningioma from other tumours is 75%, specificity 87%, positive predictive value 33% and negative predictive value 97%. Mean E of malignant brain tumours (8.3, n=31, 23 primary, eight secondary), except anaplastic gliomas (3.5, n=5), differed significantly (P=0.02) from those of benign gliomas (3, n=9) but not from that of meningioma (11.9, n=4). The cut-off value for distinguishing malignant from benign lesions on the basis of E set at 4.8 resulted in sensitivity 67%, specificity 75%, accuracy 70%, positive predictive value 80% and negative predictive value 60%. D and R showed tendency of wash-out of MIBI from meningiomas, but otherwise did not improve the results substantially. CONCLUSION: Integrated results of RCA and SPET with Tc-MIBI indicate that blood perfusion, blood-tumour barrier permeability and metabolic activity of the tumour are all very important for the resultant uptake shown by SPET. If the perfusion index is less than 1.45, then meningioma can be ruled out. Early SPET is recommendable for distinguishing glioblastoma from low-grade gliomas, as a complement to standard magnetic resonance imaging and/or computed tomography.

Evaluation of myocardial perfusion and function by gated single-photon emission computed tomography technetium-99m methoxyisobutylisonitrile in children and adolescents with severe congenital heart disease.

OBJECTIVES: The value of gated single-photon emission computed tomography technetium-99m methoxyisobutylisonitrile (gated SPECT (99m)Tc-MIBI) in children is not yet established probably because gated SPECT (99m)Tc-MIBI has rarely been used in pediatric clinical and research studies. The purpose of this study was to evaluate perfusion abnormalities and left ventricular (LV) function by gated SPECT (99m)Tc-MIBI in children and adolescents with severe congenital heart disease (CHD). METHODS: Seventeen children and adolescents with severe CHD (11 boys and six girls, mean age 11+/-4 years) underwent 2-day rest-stress (11 boys) or 1-day rest (six girls) gated SPECT (99m)Tc-MIBI. Myocardial perfusion was evaluated by a 17-segment model with a 5-point score to derive the summed stress score, the summed rest score (SRS), and the summed difference score based on the 4D-MSPECT software results. The extent of myocardial perfusion abnormalities was also expressed as a percentage of the LV size. The 4D-MSPECT software was used to calculate LV end-diastolic volume, end-systolic volume (ESV), and ejection fraction (EF). RESULTS: Reversible myocardial perfusion defect was found in 7 of 11 children (64%) who underwent rest-stress gated SPECT (99m)Tc-MIBI. The LV segments involved were anterior, anteroseptal, anterolateral, apical and inferior. These seven children showed significantly larger perfusion abnormalities on stress compared with rest study (18+/-5 vs. 7+/-4%, P<0.01) and higher summed stress score compared to SRS (11+/-4 vs. 4+/-2, P<0.01). Children and adolescents with myocardial ischemia had significantly lower poststress EF than rest EF (53+/-12 vs. 59+/-11%, P<0.05) and significantly higher poststress ESV than rest ESV (81+/-24 vs. 61+/-25 ml, P<0.05). In six children evaluated only at rest, perfusion defects involved anterior, anteroseptal and apical, or inferolateral segments, accounting for 31+/-12% of LV and with SRS of 12+/-5. Their global LV parameters were: end-diastolic volume 118+/-23 ml, ESV 56+/-16 ml, EF 51+/-10%. CONCLUSION: Poststress and rest-gated SPECT (99m)Tc-MIBI results indicate that children and adolescents with severe CHD show a range of abnormalities in myocardial perfusion and LV function, which is useful for determining functional importance of morphological malformations. Thus, gated SPECT (99m)Tc-MIBI provides complementary information that may guide clinical decision making in children and adolescents with severe CHD.

One-year follow-up of myocardial perfusion and function evaluated by gated SPECT MIBI in patients with earlier myocardial infarction and chronic total occlusion.

OBJECTIVE: Optimal treatment for chronic total occlusion (CTO) in the infarct-related coronary artery is not clear. Our aim was to assess myocardial perfusion, left ventricular ejection fraction (EF), and left ventricular size using gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging with 99mTc-methoxy-isobutyl-isonitrile in patients with CTO before and 1 year after recanalization. METHODS: Thirty patients with earlier myocardial infarction and at least one CTO underwent percutaneous coronary intervention (PCI) as well as nitrate-enhanced gated SPECT myocardial perfusion and dobutamine stress echocardiography before and 11 +/- 1 months after recanalization. They were divided into three groups based on the outcome of the follow-up angiography: (i) successful recanalization with no evidence of in-stent restenosis (n=13); (ii) successful recanalization with in-stent restenosis (n=7) and (iii) unsuccessful recanalization (n=10). RESULTS: Overall success of recanalization for CTO was 74%. In group 1, myocardial viability was preserved in 11 of 13 (85%) patients at baseline. Gated SPECT at 1 year showed a significant decrease in perfusion abnormalities (29 +/- 12 to 23 +/- 14%, P < 0.05) and left ventricular end-diastolic volume (EDV) (168 +/- 47 to 151 +/- 47 ml, P < 0.05). Improvement in EF (51 +/- 11 to 54 +/- 13%, P > 0.05) and reduction in left ventricular end-systolic volume (ESV) (84 +/- 37 to 77 +/- 40 ml, P > 0.05) did not reach the level of significance. Myocardial viability was preserved in only two of seven patients (28%) in group 2. Neither mean perfusion abnormalities (37 +/- 24 to 35 +/- 22%, P > 0.05) nor global left ventricular parameters (EF 41 +/- 15 vs. 42 +/- 19%, EDV 298 +/- 33 vs. 299 +/- 57 mL, ESV 197 +/- 12 vs. 195 +/- 32 ml; P > 0.05) changed at the follow-up. In group 3, myocardial viability was preserved in seven of 10 patients (70%) at baseline, but no significant changes in perfusion (40 +/- 18 vs. 41 +/- 19%, P > 0.05) and left ventricular function (EF 42 +/- 17 vs. 44 +/- 14%, EDV 228 +/- 101 vs. 227 +/- 81 ml, ESV 143 +/- 87 vs. 146 +/- 8 ml; P > 0.05) were seen at the follow-up. CONCLUSION: Myocardial perfusion and EDV may significantly improve 1 year after PCI provided recanalization of CTO was successful. Our preliminary findings suggest that successful recanalization of CTO may have favorable outcome on left ventricular perfusion and function, particularly in patients with viable myocardium before PCI. The gated SPECT myocardial perfusion imaging with 99mTc-methoxy-isobutyl-isonitrile may be useful for monitoring long-term functional outcome of PCI in patients with CTO.

Site of myocardial infarction and severity of perfusion abnormalities impact on post-stress left ventricular function in patients with single-vessel disease: gated single-photon emission computed tomography methoxyisobutylisonitrile study.

OBJECTIVES: We used gated single-photon emission computed tomography methoxyisobutylisonitrile (SPECT MIBI) to (i) determine whether location of myocardial infarction (MI) and severity of perfusion abnormalities affect post-stress left ventricular function in patients with single-vessel coronary artery disease, and (ii) correlate changes between post-stress and rest ejection fraction (EF) with the severity of perfusion and regional wall motion abnormalities (RWMAs). METHODS: Eighty-eight patients with a history (> or =3 months) of anterior MI (n=45) or inferior MI (n=43) underwent a 2-day stress-rest gated SPECT MIBI. 4D-MSPECT software was used to calculate left ventricular end-diastolic volume (EDV), end-systolic volume (ESV), EF, and the difference from post-stress to rest EF (EFs-EFr). Summed stress scores, summed rest scores, and summed difference scores (SDS) were calculated based on the 17-segment model. RWMAs were visually assessed using a 5-point score. RESULTS: Patients with anterior MI, compared with those with inferior MI, showed significantly greater perfusion abnormalities (summed stress score 11.0+/-5.5 vs. 7.5+/-2.4, P<0.01, summed rest score 7.4+/-4.7 vs. 5.2+/-1.9, P<0.01, SDS 3.3+/-1.0 vs. 1.9+/-1.0, P<0.05) and higher post-stress and rest RWMA (RWMSS 12.2+/-6.0 vs. 8.7+/-4.1, P<0.01, RWMRS 8.7+/-5.4 vs. 5.6+/-3.0, P<0.01). In 22 patients with anterior reversible ischemia in addition to fixed defect, post-stress and rest EDV and ESV were significantly larger and post-stress EF decreased more than in 21 patients with inferior MI (EDV 144.0+/-28.9 ml vs. 108.6+/-36.9 ml, ESV 70.6+/-22.2 ml vs. 53.4+/-20.5 ml, EFs-EFr -4.2+/-3.5% vs. -1.5+/-2.2%, P<0.01). SDS and RWMA were highly correlated with EFs-EFr. CONCLUSION: In patients with single-vessel coronary artery disease, the extent and severity of perfusion and RWMAs assessed by gated SPECT MIBI are greater after anterior MI than inferior MI. Global left ventricular function is significantly more affected after anterior MI only in patients with reversible ischemia in addition to fixed wall defect. Decrease in EF from post-stress to rest is closely associated with the severity of perfusion and RWMAs. Overall results suggest that the extent and severity of perfusion and RWMAs are more prominent in the myocardial region supplied by left anterior descending coronary artery than by right coronary artery, which may explain significantly worse post-stress left ventricular function after anterior MI.

Evaluation of undifferentiated carcinoma of nasopharyngeal type with thallium-201 and technetium-99m MIBI SPECT.

OBJECTIVE: To determine the value of 201-thallium (201-Tl) and technetium-99m sestamibi (Tc-99m MIBI) single photon emission computed tomography (SPECT) for detecting primary undifferentiated carcinoma of nasopharyngeal type (UCNT), residual/recurrent tissue, and lymph node involvement. STUDY DESIGN AND SETTING: SPECT of head and neck was prospectively performed in 46 patients with a history of UCNT (201-Tl in 24 patients, Tc-99m MIBI in 22). CT/MRI findings, clinical follow-up, and pathohistological verification served as a gold standard for calculating sensitivity, specificity, and accuracy of each scintigraphic technique. Tumor-to-background index (T/Bg) was derived when SPECT findings were positive. RESULTS: Sensitivity of 201-Tl SPECT was 87 percent, with 78 percent specificity, 83 percent accuracy, and T/Bg of 4.05 +/- 1.50. Tc-99m MIBI SPECT had 85 percent sensitivity, 78 percent specificity, 82 percent accuracy, and T/Bg of 4.45 +/- 1.27. CONCLUSION AND SIGNIFICANCE: 201-Tl SPECT and Tc-99m MIBI SPECT are useful for detecting primary UCNT, residual/recurrent disease, and lymph node involvement. This use is particularly valuable after chemoradiotherapy when CT/MRI may be ambiguous.