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ABSTRACT: When confronted with a suspicious rise in CA 15.3 in asymptomatic breast cancer patients following primary treatment and negative or equivocal conventional imaging findings, FDG PET/CT allows assessment of the site and extent of the recurring disease with an accuracy of 83 %. Both FDG PET and FDG PET/CT are superior when compared to CT alone for the purpose of recurrence detection in patients suffering from ovarian carcinoma who have completed primary therapy but demonstrate a rising serum CA-125 level. As the global accuracy of CT alone for detection of recurrence of ovarian cancer approximates 80 %, CT scan should be performed upfront to identify the site of recurrence. When confronted with negative or equivocal CT findings, FDG PET alone or FDG PET/CT should be added. In patients with rising serum CEA levels that have undergone primary treatment for a colorectal carcinoma, both FDG PET and FDG PET/CT allow detection of tumor recurrence with an accuracy of 95 %, well above that of CT and MRI. Available studies further suggest that FDG/PET findings will affect treatment management in 28-50 % of these patients. The detection rate of both 11C-choline and 18F-choline PET and PET/CT for local, regional, and distant recurrence in prostate carcinoma patients with a biochemical recurrence increases with rising PSA value at the time of imaging and reaches about 75 % in patients with PSA >3 ng/mL. Furthermore, PET and PET/CT with [(11)C]- and [(18)F]-choline derivates may be helpful in the clinical setting for optimization of individualized treatment.
Annals of Nuclear Medicine 02/2013; 27(2):97-104. · 1.50 Impact Factor
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ABSTRACT: Data available in patients suffering from squamous cell carcinoma of the head and neck, lung carcinoma, oesophageal carcinoma and gynaecological malignancies suggest that metabolic tumour volume and to a lesser extent total lesion glycolysis have the potential to become valuable in the imaging of human solid tumours as prognostic biomarkers for short- to intermediate-term survival outcomes, adding value to clinical staging, for assessment of response to treatment with neoadjuvant and concurrent chemotherapy, and for treatment optimization; for example, based on early treatment response assessment using changes in metabolic tumour volume over time, it might be possible to select patients who require a more aggressive treatment to improve their outcome. Prospective studies enrolling consecutive patients, adopting standardized protocols for FDG PET acquisition and processing, adjusting for potential confounders in the analysis (tumour size and origin) and determining the optimal methodology for determination of these novel markers are mandatory.
European Journal of Nuclear Medicine 11/2012; · 4.53 Impact Factor
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ABSTRACT: Available literature on the differences in circulation and microcirculation of normal liver and liver metastases as well as in rheology of the different radiolabelled microspheres [(99m)Tc-labelled macroaggregates of albumin (MAA), (90)Y-TheraSpheres and (90)Y-SIR-spheres] used in selective internal radiation therapy (SIRT) are reviewed and implications thereof on the practice of SIRT discussed. As a result of axial accumulation and skimming, large microspheres are preferentially deposited in regions of high flow, whereas smaller microspheres are preferentially diverted to regions of low flow. As flow to normal liver tissue is considerably variable between segments and also within one segment, microspheres will be delivered heterogeneously within the microvasculature of normal liver tissue. This non-uniformity in microsphere distribution in normal liver tissue has a significant "liver-sparing" effect on the dose distribution of (90)Y-labelled microspheres. Arterial flow to liver metastases is most pronounced in the hypervascular rim of metastases, followed by the smaller metastases and finally by the central hypoperfused region of the larger metastases. Because of the wide variability in size of labelled MAAs and because of the skimming effect, existing differences in flow between metastatic lesions of variable size are likely exaggerated on (99m)Tc-MAA scintigraphy when compared to (90)Y-TheraSpheres and (90)Y-SIR-spheres (smaller variability in size and probably also in specific activity). Ideally, labelled MAAs would contain a size range similar to that of (90)Y-SIR-spheres or (90)Y-TheraSpheres. Furthermore, the optimal number of MAA particles to inject for the pretreatment planning scintigraphy warrants further exploration as it was shown that concentrated suspensions of microspheres produce more optimal tumour to normal liver distribution ratios. Finally, available data suggest that the flow-based heterogeneous distribution of microspheres to metastatic lesions of variable size might be optimized, that is rendered more homogeneous, through the combined use of angiotensin II and degradable starch microspheres.
European Journal of Nuclear Medicine 07/2012; 39(10):1646-55. · 4.53 Impact Factor
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ABSTRACT: No data is available on the different FDG PET and CT findings in the lymph nodes (LN) of patients with HIV and tuberculosis (TB) who respond compared with those who do not respond to anti-TB treatment by 4 months after initiation of TB treatment. These findings were the focus of our study.
PET/CT scans performed at 4 months after initiation of TB treatment in 20 consecutive HIV patients were analysed. SUVmax values were obtained for all regions of LN involvement. The diameter of the LNs was measured and the CT enhancement (LNs showing peripheral rim enhancement with central low attenuation, PRECLO, in comparison with homogeneously involved LNs) and the calcification patterns of involved LNs assessed. The relationship between the PET and CT findings and the clinical outcome, response or nonresponse, was evaluated.
FDG PET identified 91 sites of LN involvement, 20 of which were not identified by CT. SUVmax values were significantly higher in nonresponders (8 patients, SUVmax 11.2 ± 4.0, mean ± SD) when compared to responders (12 patients, SUVmax 2.6 ± 2.3; p = 0.0001). In ROC analysis (AUC 0.952) a cut-off value of 4.5 for SUVmax yielded a sensitivity and specificity of 95% and 85% for discriminating nonresponding from responding LNs. LNs were significantly larger in nonresponders (1.9 ± 0.4 cm) than in responders (1.4 ± 0.4 cm; p = 0.0001); the AUC in the ROC analysis was 0.76. PRECLO LNs were significantly larger (2.2 ± 0.3 cm) than homogeneous involved LN basins (1.5 ± 0.4 cm) and LN basins with calcification (1.4 ± 0.5 cm; p = 0.001). Using the presence of at least one LN basin with PRECLO as a criterion for nonresponse, responders could be separated from nonresponders with a sensitivity of 88% and a specificity of 66%.
LNs responding to TB treatment could be differentiated from nonresponding LNs with a sensitivity and specificity of 95% and 85% using a SUVmax cut-off value of 4.5 and a sensitivity and specificity of 88% and 66% using the presence of at least one LN basin with PRECLO.
European Journal of Nuclear Medicine 04/2012; 39(7):1184-90. · 4.53 Impact Factor
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ABSTRACT: In this paper, data available on nuclear medicine imaging using commercially available radiopharmaceuticals for the differentiation, staging, and prediction or assessment of the response to treatment in tuberculosis (TB) are reviewed. Limited available studies suggest that single photon emission computed tomography (SPECT) using either 201Tl, 99mTc-sestamibi, or 99mTc-tetrofosmin is accurate (≥85%) and has a high negative predictive value (≥90%) for the differentiation of TB from carcinoma in patients presenting with a solitary pulmonary nodule (SPN). The criteria for detection of TB on 201Tl SPECT are nondepiction of the suspicious lesion in the delayed image or a negative retention index [washout on the delayed images (3–4 h postinjection) vs. the early image (5–15 min postinjection)] and a comparable-to-background uptake on 99mTc-sestamibi or 99mTc-tetrofosmin SPECT. Another SPECT tracer of potential interest for the differentiation of TB from malignant SPN that warrants further exploration, is N-isopropyl-p-[123I]iodoamphetamine (123I-IMP). In contrast, 18F-fluorodeoxyglucose (18F-FDG) PET is unable to differentiate malignancy from TB and thus cannot be used as a tool to reduce futile biopsy/thoracotomy in these patients. A limited number of studies have reported on the potential of nuclear medicine imaging in assessment of the extent of disease in patients with extrapulmonary TB using 67Ga-citrate SPECT and 18F-FDG PET, respectively. 67Ga-citrate SPECT was shown to be as sensitive as bone scintigraphy for the detection of bone infection and was found to be complementary to computed tomography (CT) imaging. 18F-FDG PET was found to be significantly more efficient when compared with CT, respectively, in over half of patients for the identification of sites of lymph node involvement that were missed by CT and often the only sites of extrapulmonary TB identified. Unfortunately, 18F-FDG PET findings did not lead to alterations in treatment planning in any of the patients under study. Additional studies confirming these findings are urgently required. Similar to the setting of SPN, 18F-FDG PET cannot differentiate malignant lymph node involvement from lymph node involvement by TB. These results and the recent findings of Demura and colleagues using 18F-FDG PET further suggest that nuclear medicine imaging techniques could be used for the evaluation of therapeutic response. Prospective studies, focusing on specific subgroups of patients in whom such an imaging approach might be clinically relevant, for example in multidrug-resistant TB patients, are warranted. In acquired immunodeficiency syndrome patients, 67Ga scintigraphy proved to be a reliable and sensitive method for the primary detection and follow-up of opportunistic pneumonias, including TB. Combining 201Tl scintigraphy with 67Ga scintigraphy was shown to increase the specificity for both pulmonary and extrapulmonary TB, which is a 67Ga(+) and 201Tl(-) mismatch pattern in acquired immunodeficiency syndrome patients that is specific for mycobacterial infections. Finally, the results obtained using both SPECT and PET indicate that nuclear medicine could be an important noninvasive method for the determination of disease activity, detection of extrapulmonary TB, and determination of response to therapy.
Nuclear Medicine Communications 03/2012; 33(6):581-90. · 1.40 Impact Factor
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ABSTRACT: This prospective pilot study examined the relationship between the severity and extent of tuberculosis as assessed by (18)F-FDG PET at the time of diagnosis and response to treatment or treatment failure at 4 mo.
Twenty-four consecutive HIV patients with newly diagnosed tuberculosis were prospectively included in the study after providing written informed consent. Seventeen patients had pulmonary tuberculosis, and 7 patients had extrapulmonary tuberculosis. All patients underwent whole-body (18)F-FDG PET; none were receiving tuberculostatics at the time of the PET investigation. After undergoing (18)F-FDG PET, the patients were given tuberculosis treatment (the classic triad: isoniazid, rifampicin, and ethambutol) and reevaluated for treatment response: monthly assessment of sputum, smears, and cultures in patients who proved positive at the time of diagnosis, and clinical and radiologic (when relevant) assessment 4 mo after treatment instigation in all patients. Quantitative (18)F-FDG PET results (averaged (18)F-FDG maximum standardized uptake value [SUVmax] derived from early and delayed imaging), percentage change in SUVmax, and number of involved lymph node bastions were related to treatment response or failure.
Age, sex, viral load, CD4 status, duration of HIV treatment, SUVmax of lung and splenic lesions (early and delayed), and percentage change in SUVmax of lymph nodes were not significantly different between responders and nonresponders (P ≥ 0.3). In contrast, SUVmax of involved lymph node bastions (both early and delayed) and number of involved lymph node bastions were significantly higher in nonresponders than in responders (respective P values were 0.03, 0.04, and 0.002). Using a cutoff of 5 or more involved lymph node bastions, responders could be separated from nonresponders with a sensitivity, specificity, and positive and negative predictive value of, respectively, 88%, 81%, 70%, and 93%. Using a cutoff of 8.15 for early SUVmax of lymph node bastions and of 10 for late SUVmax of lymph node bastions, a comparable sensitivity of 88% came at the cost of a lower specificity: 73% and 67%, respectively.
In this pilot study, a cutoff of 5 or more involved lymph node bastions allowed for separation of tuberculostatic responsive and nonresponsive tuberculosis-infected HIV patients with a sensitivity of 88%, a specificity of 81%, and a negative predictive value of 93%. These findings warrant confirmation by additional studies on larger cohorts of patients.
Journal of Nuclear Medicine 06/2011; 52(6):880-5. · 6.38 Impact Factor
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ABSTRACT: Fluorodeoxyglucose (FDG)-positron emission tomography (PET) is an accurate non-invasive imaging test for differentiating benign from malignant solitary pulmonary nodules (SPNs). We aimed to assess its diagnostic accuracy for differentiating benign from malignant SPNs in a tuberculosis (TB)-endemic area.
Thirty patients, 22 men and 8 women, mean age 60 years, underwent dual time point FDG-PET/computed tomography (CT) imaging, followed by histological examination of the SPN. Maximum standard uptake values (SUVmax) with the greatest uptake in the lesion were calculated for two time points (SUV1 and SUV2), and the percentage change over time per lesion was calculated (%DSUV). Routine histological findings served as the gold standard.
Histological examination showed that 14 lesions were malignant and 16 benign, 12 of which were TB. SUVmax for benign and malignant lesions were 11.02 (standard deviation (SD) 6.6) v. 10.86 (SD 8.9); however, when tuberculomas were excluded from the analysis, a significant difference in mean SUV1max values between benign and malignant lesions was observed (p=0.0059). Using an SUVmax cut-off value of 2.5, a sensitivity of 85.7% and a specificity of 25% was obtained. Omitting the TB patients from analysis resulted in a sensitivity of 85.7% and a specificity of 100%. Mean %DSUV of benign lesions did not differ significantly from mean %DSUV of malignant lesions (17.1% (SD 16.3%) v. 19.4% (SD 23.7%)). Using a cut-off of %DSUV>10% as indicative of malignancy, a sensitivity of 85.7% and a specificity of 50% was obtained. Omitting the TB patients from the analysis yielded a sensitivity of 85.7% and a specificity of 75%.
Our findings suggest that FDG-PET cannot distinguish malignancy from tuberculoma and therefore cannot reliably be used to reduce futile biopsy/thoracotomy.
South African medical journal = Suid-Afrikaanse tydskrif vir geneeskunde 09/2010; 100(9):598-601. · 2.04 Impact Factor
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ABSTRACT: To evaluate differences in glucose uptake by skeletal muscle tissue and subcutaneous fat in HIV patients on highly active antiretroviral therapy (HAART) presenting with and without lipodystrophy as well as in drug-naive HIV patients using F-fluorodeoxyglucose (FDG) positron emission tomography.
Thirty-nine consecutive patients suffering from HIV: seven drug-naive patients, 21 nonlipodystrophic patients on HAART and 11 patients on HAART, respectively, suffering from lipodystrophy were prospectively included. All patients underwent a whole-body FDG positron emission tomography examination. Standardized uptake values (SUV values) of muscle and subcutaneous fat were compared and related to demographic and biochemical variables.
SUV mean values of subcutaneous fat were significantly higher in patients under HAART presenting with lipodystrophy when compared with untreated and treated, nonlipodystrophic patients (P=0.000). SUV mean values of subcutaneous fat significantly correlated with treatment duration (r=0.56, P=0.000) and CD4 count (r=0.51, P=0.001) and inversely correlated with viral load (r=-0.61, P=0.000). Finally, SUV mean values of thigh muscles were not significantly different between the three different patient groups under study.
Quantitative FDG uptake by subcutaneous fat proved significantly higher in HIV patients under HAART presenting with lipodystrophy. HAART did not influence FDG uptake by human skeletal muscle tissue under basal conditions.
Nuclear Medicine Communications 02/2010; 31(4):311-4. · 1.40 Impact Factor
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ABSTRACT: To assess prospectively the relationship between fluorodeoxyglucose uptake by lymph nodes, the number of sites of lymph node involvement and cluster of differentiation 4 (CD4) cell count. An inverse relationship, if existing, between these variables would provide indirect support for the concept of homing induced apoptosis.
We evaluated the intensity and extent of fluorodeoxyglucose uptake in lymph nodes of HIV patients under antiviral treatment by means of PET imaging. Quantitative results obtained were related to CD4 cell count and viral loads. Correlation analysis was performed using a nonparametric test and correction for multiple comparisons.
Predominant sites of lymph node involvement were the cervical and axillary regions, followed by the inguinal region. CD4 cell count was inversely correlated to the average of the averaged standardized uptake values (SUV) of involved lymph nodes and to the number of sites of lymph node involvement. Viral load was positively correlated to the average of the averaged SUV-mean values of involved lymph nodes and also to the number of sites of lymph nodes involved. An inverse correlation between CD4 cell count and viral load was identified.
The inverse relationship between CD4 cell count and the average of the averaged SUV-mean values of involved lymph nodes and between CD4 cell count and the number of sites of lymph node involvement observed, indirectly supports the theory of CD4 cell depletion through forced lymph node homing.
Nuclear Medicine Communications 12/2009; 31(2):137-40. · 1.40 Impact Factor
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ABSTRACT: Locoregional lymph node metastasis is an important prognostic factor in patients with bladder cancer. Multimodal treatment, depending on preoperative stage, may improve survival. The standard imaging modalities for staging (computed tomography [CT] or magnetic resonance imaging [MRI]) have an accuracy range of 70-90% for lymph node staging. A more accurate preoperative diagnostic test could improve survival rates even more.
To determine whether the use of 2-deoxy-2 [F] fluoro-D-glucose (FDG) positron emission tomography (PET) in combination with CT (FDG-PET/CT) can increase the reliability of preoperative lymph node staging in patients with nonmetastatic invasive bladder cancer (T2 or higher, M0) or recurrent high-risk superficial disease (T1G3 with or without Tis, M0).
Fifty-one patients underwent a preoperative FDG-PET/CT between April 2004 and December 2007. Independent of the result for lymph node status, all patients underwent a radical cystectomy and an extended lymphadenectomy. The FDG-PET/CT and CT results were compared with the definitive pathologic results.
Among the 51 patients, 13 patients had metastatically involved locoregional lymph nodes, diagnosed on histopathology. In six patients, these nodes demonstrated increased FDG uptake on PET. In seven patients, PET/CT did not diagnose the positive lymph nodes. PET/CT was false positive in one patient.
For the diagnosis of node-positive disease, the accuracy, the sensitivity, and the specificity of FDG-PET/CT were 84%, 46%, and 97%, respectively. When analysing the results of CT alone, there was accuracy of 80%, sensitivity of 46%, and specificity of 92%. The use of FDG-PET/CT is hampered by technical limitations.
We found no advantage for combined FDG-PET/CT over CT alone for lymph node staging of invasive bladder cancer or recurrent high-risk superficial disease.
European urology 06/2009; 57(4):641-7. · 7.67 Impact Factor
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Nuclear Medicine Communications 05/2009; 30(4):255-7. · 1.40 Impact Factor
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ABSTRACT: This paper reviews currently available PET studies performed either to improve our understanding of the pathogenesis of HIV-1 infection or to assess the value of PET imaging in the clinical decision making of patients infected with HIV-1 presenting with AIDS-related opportunistic infections and malignancies. FDG PET has shown that HIV-1 infection progresses by distinct anatomical steps, with involvement of the upper torso preceding involvement of the lower part of the torso, and that the degree of FDG uptake relates to viral load. The former finding suggests that lymphoid tissues are engaged in a predictable sequence and that diffusible mediators of activation might be important targets for vaccine or therapeutic intervention strategies. In lipodystrophic HIV-infected patients, limited available data support the hypothesis that stavudine-related lipodystrophy is associated with increased glucose uptake by adipose tissue as a result of the metabolic stress of adipose tissue in response to highly active antiretroviral treatment (HAART). Finally, in early AIDS-related dementia complex (ADC), striatal hypermetabolism is observed, whereas progressive ADC is characterized by a decrease in subcortical and cortical metabolism. In the clinical setting, PET has been shown to allow the differentiation of AIDS-related opportunistic infections and malignancies, and to allow monitoring of side effects of HAART. However, in patients suffering from HIV infection and presenting with extracerebral lymphoma or other human malignancies, knowledge of viraemia is essential when interpreting FDG PET imaging.
European Journal of Nuclear Medicine 05/2009; 36(7):1176-84. · 4.53 Impact Factor
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ABSTRACT: To investigate dynamic ictal perfusion changes during temporal lobe epilepsy (TLE).
We investigated 37 patients with TLE by ictal and interictal SPECT. All ictal injections were performed within 60 s of seizure onset. Statistical parametric mapping was used to analyse brain perfusion changes and temporal relationships with injection time and seizure duration as covariates.
The analysis revealed significant ictal hyperperfusion in the ipsilateral temporal lobe extending to subcortical regions. Hypoperfusion was observed in large extratemporal areas. There were also significant dynamic changes in several extratemporal regions: ipsilateral orbitofrontal and bilateral superior frontal gyri and the contralateral cerebellum and ipsilateral striatum.
The study demonstrated early dynamic perfusion changes in extratemporal regions probably involved in both propagation of epileptic activity and initiation of inhibitory mechanisms.
European Journal of Nuclear Medicine 02/2009; 36(5):823-30. · 4.53 Impact Factor
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ABSTRACT: MR imaging, ictal single-photon emission CT (SPECT) and ictal EEG play important roles in the presurgical localization of epileptic foci. This multi-center study was established to investigate whether the complementary role of perfusion SPECT, MRI and EEG for presurgical localization of temporal lobe epilepsy could be confirmed in a prospective setting involving centers from India, Thailand, Italy and Argentina.
We studied 74 patients who underwent interictal and ictal EEG, interictal and ictal SPECT and MRI before surgery of the temporal lobe. In all but three patients, histology was reported. The clinical outcome was assessed using Engel's classification. Sensitivity values of all imaging modalities were calculated, and the add-on value of SPECT was assessed.
Outcome (Engel's classification) in 74 patients was class I, 89%; class II, 7%; class III, 3%; and IV, 1%. Regarding the localization of seizure origin, sensitivity was 84% for ictal SPECT, 70% for ictal EEG, 86% for MRI, 55% for interictal SPECT and 40% for interictal EEG. Add-on value of ictal SPECT was shown by its ability to correctly localize 17/22 (77%) of the seizure foci missed by ictal EEG and 8/10 (80%) of the seizure foci not detected by MRI.
This prospective multi-center trial, involving centers from different parts of the world, confirms that ictal perfusion SPECT is an effective diagnostic modality for correctly identifying seizure origin in temporal lobe epilepsy, providing complementary information to ictal EEG and MRI.
European Journal of Nuclear Medicine 02/2008; 35(1):107-15. · 4.53 Impact Factor
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Paul Mertens, Alex Maes,
Johan Nuyts,
Ann Belmans,
Walter Desmet,
Enric Esplugas,
Filip Charlier,
Jaime Figueras,
Gianmario Sambuceti,
Markus Schwaiger,
Luc Mortelmans,
Frans Van de Werf
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ABSTRACT: Inflammatory responses induced by reperfusion of previously ischemic myocardial tissue may lead to further damage of the microvascular structures. A group of cell adhesion molecules, named selectins, initiate those inflammatory changes at the endothelial wall surface. Recombinant P-selectin glycoprotein ligand-immunoglobulin (rPSGL-Ig), a P-selectin antagonist, was shown to have beneficial effects in several animal models of acute myocardial ischemia. We performed a mechanistic study with positron emission tomography to test the potential benefits of rPSGL-Ig in patients with ST-segment elevation acute myocardial infarction.
Patients with ST-elevation acute myocardial infarction presenting within the first 6 hours of onset of chest pain were enrolled. All patients received alteplase. Patients were randomly assigned in a 1:1:1 ratio to 3 treatment groups: placebo; 75 mg rPSGL-Ig; 150 mg rPSGL-Ig, given intravenously. Coronary angiography was performed 90 minutes after the start of thrombolytic therapy for TIMI flow grading. Myocardial blood flow (MBF) was measured with 13NH3 at rest and after adenosine administration on day 5. Myocardial blood flow at rest was measured again at day 30, followed by measurement of 18FDG uptake. In addition, a multigated acquisition, gated equilibrium blood pool study was performed at day 30. Continuous 12-lead electrocardiogram recording was performed during the first 24 hours.
The trial was prematurely stopped by the sponsor for lack of efficacy in an accompanying larger trial after enrolling 88 patients in the current study. Median MBF in the infarct-related territory (expressed as percentage of the normalized blood flow) at day 5 was similar in the 3 treatment groups (9.1% in the placebo group vs 3.8% in the 75-mg dose and 4.3% in the 150-mg rPSGL-Ig treatment group; P = not significant). No significant differences in MBF reserve, myocardial metabolism, ST-segment resolution, left ventricular ejection fraction, or TIMI flow grade were found among the 3 groups.
In this prematurely stopped mechanistic study, there was no evidence of a benefit of rPSGL-Ig given as an adjunct to thrombolysis on epicardial vessel patency, myocardial tissue reperfusion, or recovery of function.
American heart journal 08/2006; 152(1):125.e1-8. · 4.65 Impact Factor
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ABSTRACT: Clinical differential diagnosis in parkinsonism can be difficult especially at early stages. We investigated whether combined perfusion and dopamine transporter (DAT) imaging can aid in the differential diagnosis of parkinsonian disorders: idiopathic Parkinson's disease (IPD), progressive supranuclear palsy (PSP), multiple system atrophy (MSA), dementia with Lewy bodies (LBD), and essential tremor (ET).
One hundred twenty-nine patients were studied, retrospectively (69 males; 24 MSA, 12 PSP, 8 LBD, 27 ET, and 58 IPD; mean disease duration, 3.5 +/- 3.7 y). Diagnosis was based on established clinical criteria after follow-up of 5.5 +/- 3.8 y in a university specialist movement disorders clinic. Group characterization was done using a categoric voxel-based design and, second, a predefined volume-of-interest approach along Brodmann areas (BA) and subcortical structures, including striatal asymmetry and anteroposterior indices. Stepwise forward discriminant analysis was performed with cross-validation (CV) using the leave-one-out technique.
Characteristic patterns for perfusion and DAT were found for all pathologies. In the parkinson-plus group, MSA, PSP, and LBD could be discriminated in 100% (+CV) of the cases. When including IPD, discrimination accuracy was 82.4% (99% without CV). 2beta-Carbomethoxy-3beta-(4-iodophenyl)nortropane imaging as a single technique was able to discriminate between ET and neurodegenerative forms with an accuracy of 93.0% (+CV); inclusion of perfusion information augmented this slightly to 97.4% (+CV).
Dual-tracer DAT and perfusion SPECT in combination with discrimination analysis allows an automated, accurate differentiation between the most common forms of parkinsonism in a clinically relevant setting.
Journal of Nuclear Medicine 04/2006; 47(3):384-92. · 6.38 Impact Factor
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ABSTRACT: We compared the accuracy of fluorine-18 labelled 2-fluoro-2-deoxy- d-glucose positron emission tomography ((18)FDG PET) with that of technetium-99m hexamethylpropylene amine oxime leucocyte scintigraphy (LS) in the detection of infected hip prosthesis. Seventeen patients with a hip prosthesis suspected for infection were prospectively included and underwent (99m)Tc-methylene diphosphonate bone scintigraphy (BS), LS and an (18)FDG-PET scan within a 2-week period. Seven volunteers with ten asymptomatic hip prostheses were used as a control group and underwent BS and an (18)FDG-PET scan. Bacteriology of samples obtained by surgery or by needle aspiration and/or clinical follow-up for up to 6 months were used as the gold standard. Planar images of BS and LS (4 and 24 h p.i.) were acquired, followed by single-photon emission tomography (SPET) LS images (after 4 h). These images were scored as positive or negative by two experienced readers. The (18)FDG-PET scans of the patients were compared with the tracer distribution pattern in the asymptomatic control group and with BS. A phantom study was performed in order to identify artefacts. For this purpose, three different attenuation correction methods were tested. The combined analysis of the planar BS and LS resulted in a 75% sensitivity and a 78% specificity. The SPET LS images showed a better lesion contrast, resulting in an 88% sensitivity and a 100% specificity, while 24-h planar images were of no additional value. The analysis of PET images alone resulted in an 88% sensitivity and a 78% specificity. The combination of (18)FDG-PET and BS images resulted in an 88% sensitivity and a 67% specificity. Given the presence of small errors near the edge of the metal, which can induce significant artefacts in the corrected emission image, we decided to use the data without attenuation correction. In this preliminary study, (18)FDG-PET scans alone showed the same sensitivity as combined BS and LS, although the specificity was slightly lower.
European journal of nuclear medicine and molecular imaging 06/2003; 30(5):705-15. · 4.99 Impact Factor
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ABSTRACT: We compared the accuracy of fluorine-18 labelled 2-fluoro-2-deoxy-d-glucose positron emission tomography (18FDG PET) with that of technetium-99m hexamethylpropylene amine oxime leucocyte scintigraphy (LS) in the detection of infected hip prosthesis. Seventeen patients with a hip prosthesis suspected for infection were prospectively included and underwent 99mTc-methylene diphosphonate bone scintigraphy (BS), LS and an 18FDG-PET scan within a 2-week period. Seven volunteers with ten asymptomatic hip prostheses were used as a control group and underwent BS and an 18FDG-PET scan. Bacteriology of samples obtained by surgery or by needle aspiration and/or clinical follow-up for up to 6 months were used as the gold standard. Planar images of BS and LS (4 and 24 h p.i.) were acquired, followed by single-photon emission tomography (SPET) LS images (after 4 h). These images were scored as positive or negative by two experienced readers. The 18FDG-PET scans of the patients were compared with the tracer distribution pattern in the asymptomatic control group and with BS. A phantom study was performed in order to identify artefacts. For this purpose, three different attenuation correction methods were tested. The combined analysis of the planar BS and LS resulted in a 75% sensitivity and a 78% specificity. The SPET LS images showed a better lesion contrast, resulting in an 88% sensitivity and a 100% specificity, while 24-h planar images were of no additional value. The analysis of PET images alone resulted in an 88% sensitivity and a 78% specificity. The combination of 18FDG-PET and BS images resulted in an 88% sensitivity and a 67% specificity. Given the presence of small errors near the edge of the metal, which can induce significant artefacts in the corrected emission image, we decided to use the data without attenuation correction. In this preliminary study, 18FDG-PET scans alone showed the same sensitivity as combined BS and LS, although the specificity was slightly lower.
European journal of nuclear medicine and molecular imaging 04/2003; 30(5):705-715. · 4.99 Impact Factor
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Frank Weidemann,
Christoph Dommke,
Bart Bijnens,
Piet Claus,
Jan D'hooge,
Paul Mertens,
Eric Verbeken, Alex Maes,
Frans Van de Werf,
Ivan De Scheerder,
George R Sutherland
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ABSTRACT: In a correlative functional/histopathologic study, we investigated the regional deformation characteristics of both chronic nontransmural and transmural infarctions before and after a dobutamine challenge.
After stenosing copper-coated stent implantation to produce circumflex artery endothelial proliferation, 18 pigs were followed up for 5 weeks. Posteuthanasia histology showed 10 to have a nontransmural and 8 a transmural infarction. Eight nonstented animals served as controls. Regional radial function was monitored by measuring ultrasound-derived peak systolic strain rates (SR(SYS)) and systolic strains (epsilon(SYS)) (1) before stent implantation and (2) at 5 weeks, at baseline (bs) and during an incremental dobutamine infusion. In controls, dobutamine induced a linear increase in SR(SYS) (dobutamine: bs, 4.8+/-0.4 s(-1); 20 microg x kg(-1) x min(-1), 9.9+/-0.7 s(-1); P<0.0001) and an initial increase of epsilon(SYS) at low dose (bs, 58+/-5%; at 5 microg x kg(-1) x min(-1), 78+/-6%; P<0.05) but a subsequent decrease during higher infusion rates. In the nontransmural group, bs SR(SYS) and epsilon(SYS) were significantly lower than prestent values (SR(SYS), 2.9+/-0.5 s(-1) and epsilon(SYS), 32+/-6%, P<0.05 versus prestent). During dobutamine infusion, SR(SYS) increased slightly at 5 microg x kg(-1) x min(-1) (4.7+/-0.6 s(-1), P<0.05) but fell during higher infusion rates, whereas epsilon(SYS) showed no change. For nontransmural infarctions, transmural scar extension correlated closely with epsilon(SYS) at bs (r=0.88). For transmural infarctions, SR(SYS) at bs was significantly reduced and epsilon(SYS) was almost not measurable (SR(SYS), 1.8+/-0.3 s(-1); epsilon(SYS), 3+/-4%). Both deformation parameters showed no further change during the incremental dobutamine infusion.
Ultrasonic deformation values could clearly differentiate chronic nontransmural from transmural myocardial infarction. The transmural extension of the scar could be defined by the regional deformation response.
Circulation 02/2003; 107(6):883-8. · 14.74 Impact Factor
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ABSTRACT: In an ongoing international multi-centre trial, positron emission tomography (PET) is being used to evaluate the effect of a new P-selectin antagonist on the infarct size in patients with acute myocardial infarction, treated with thrombolysis. Although it is possible to correct for site-dependent factors, it is desirable to reduce these factors to a minimum. Therefore, acquisition and reconstruction protocols have been defined that can be closely followed by all participating centres. The resulting reconstructed images are transferred to the core centre for central processing with semi-automatic software. This paper reports on the multi-centre phantom experiment that was carried out to assess the inter-centre reproducibility of defect size determination with this protocol. Also, the spatial resolution of the short axis slices was examined. In addition, the analysis procedure was applied to normal PET studies to evaluate the specificity of perfusion defect detection. The transmural cold defect in the phantom occupied 14.8% of the left ventricular area. The automated analysis was applied to the phantom measurements from the 14 participating PET cameras. It yielded an accurate estimate of 15.1% with a standard deviation of 0.6%, indicating excellent reproducibility. The spatial resolution in the short axis slices was similar for all PET systems: 9.6+/-0.8 mm. The same procedure produced a defect size of zero in the studies of normal volunteers. This study indicates that cardiac studies from multiple PET systems can be pooled for statistical analysis.
European journal of nuclear medicine and molecular imaging 01/2003; 29(12):1588-93. · 4.99 Impact Factor
