Molecular Imaging Diagnosis of Renal Cancer Using 99mTc-Sestamibi SPECT/CT and Girentuximab PET-CT-Current Evidence and Future Development of Novel Techniques

: Novel molecular imaging opportunities to preoperatively diagnose renal cell carcinoma is under development and will add more value in limiting the postoperative renal function loss and morbidity. We aimed to comprehensively review the research on single photon emission computed tomography/computed tomography (SPECT/CT) and positron emission tomography computed tomography (PET-CT) molecular imaging and to enhance the urologists' and radiologists' knowledge of the current research pattern. We identified an increase in prospective and also retrospective studies that researched to distinguish between benign and malignant lesions and between different clear cell renal cell carcinoma subtypes, with small numbers of patients studied, nonetheless with excellent results on specificity, sensitivity and accuracy, especially for 99mTc-sestamibi SPECT/CT that delivers quick results compared to a long acquisition time for girentuximab PET-CT, which instead gives better image quality. Nuclear medicine has helped clinicians in evaluating primary and secondary lesions, and has lately returned with new and exciting insights with novel radiotracers to reinforce its diagnostic potential in renal carcinoma. To further limit the renal function loss and post-surgery morbidity, future research is mandatory to validate the results and to clinically implement the diagnostic techniques in the context of precision medicine

Model-based correction for scatter and tailing effects in simultaneous 99mTc and 123I imaging for a CdZnTe cardiac SPECT camera

2015 Institute of Physics and Engineering in Medicine. An advantage of semiconductor-based dedicated cardiac single photon emission computed tomography (SPECT) cameras when compared to conventional Anger cameras is superior energy resolution. This provides the potential for improved separation of the photopeaks in dual radionuclide imaging, such as combined use of 99mTc and 123I . There is, however, the added complexity of tailing effects in the detectors that must be accounted for. In this paper we present a model-based correction algorithm which extracts the useful primary counts of 99mTc and 123I from projection data. Equations describing the in-patient scatter and tailing effects in the detectors are iteratively solved for both radionuclides simultaneously using a maximum a posteriori probability algorithm with one-step-late evaluation. Energy window-dependent parameters for the equations describing in-patient scatter are estimated using Monte Carlo simulations. Parameters for the equations describing tailing effects are estimated using virtually scatter-free experimental measurements on a dedicated cardiac SPECT camera with CdZnTe-detectors. When applied to a phantom study with both 99mTc and 123I, results show that the estimated spatial distribution of events from 99mTc in the 99mTc photopeak energy window is very similar to that measured in a single 99mTc phantom study. The extracted images of primary events display increased cold lesion contrasts for both 99mTc and 123I

New nuclear medicine techniques for the assessment of myocardial viability

Een dotterbehandeling of een bypassoperatie heeft alleen zin als er nog voldoende hartspierweefsel over is dat zich kan herstellen. Momenteel wordt de vitaliteit van de hartspier voor de ingreep nog onderzocht met een PET-scan, maar deze techniek is duur en maar in een paar ziekenhuizen in Nederland aanwezig. Riemer Slart constateert in zijn proefschrift dat een goedkopere scan het succes van een bypass of dotteren ook kan voorspellen.

Diagnostic value of nuclear cardiology in coronary artery disease

This thesis investigates the diagnostic value of cardiac positron emission tomography when compared to single photon emission computed tomography for detection of coronary artery disease. This prospective study involves comparison of myocardial perfusion single photon emission computed tomography with coronary calcium scores; optimization of nuclear cardiac protocols in cardiac phantom experiments; and determination of diagnostic performance of cardiac positron emission tomography in the evaluation of myocardial viability in patients with significant coronary disease

Visualization of Brown Fat Using X-ray Dark Field Imaging

Introduction: Obesity has become a major societal issue. Many researchers are looking for ways to combat this growing epidemic. Brown adipose tissue (BAT) might be a way to help individuals overcome the challenges associated with weight loss and maintenance of weight loss, but a better understanding of BAT and how to control and utilize it is needed. BAT differs from white adipose tissue (WAT) in that BAT is rich with mitochondria and therefore is metabolically active. BAT is a source of non-shivering thermogenesis and can be activated both by cold exposure and pharmacologically. Current methods of assessing BAT activity are invasive; a noninvasive method to visualize BAT is highly desirable. X-ray interferometry may be applicable to BAT imaging. Interferometry yields three images from one acquisition: an absorption image, a dark-field (DF) image, and a phase contrast image. The absorption image represents attenuation by the material, equivalent to conventional x-ray imaging; the phase contrast image shows refraction at interfaces through which the beam travels. Small angle scatter caused by microscopic structures in the material cause the DF image; DF has potential interest for BAT visualization. This study evaluated DF imaging as a means to image BAT. The expectation was the large number of mitochondria in BAT will cause a large DF signal, and furthermore that BAT activated by cold exposure would have a different DF signal than BAT at normal conditions. Materials and Methods: Mice were kept for one week at 8°C to activate BAT; control mice were kept at 22°C. Biochemical markers were used to verify BAT activation by the cold exposure regimen. DF images of cold-exposed and control mice were assessed visually and by region-of-interest analysis to determine if activated BAT could be distinguished from tissue in the same region in control mice. Absorption images provided the identification of an intrascapular region of interest for examination in the DF images. In vivo 99mTc-sestamibi SPECT was used as an independent means to assess BAT activation. Results: Biochemical markers showed that the cold exposure regimen caused activation of intrascapular BAT as well as the beiging of inguinal WAT; only the intrascapular BAT region was investigated by DF imaging. A region between the scapula and posterior to the spine was apparent in both 8°C and 22°C mice; this region did not show substantial differences in DF signal between the two groups, however. Region of interest analysis of the SPECT images showed increased uptake in the intrascapular region for cold-exposed mice, but the increase was not substantial enough to allow direct visual observation. Conclusion: Both absorption and DF imaging were capable of contrasting BAT depots from adjacent tissue in the intrascapular region. However, no significant difference in DF signal was seen for this intrascapular BAT between the cold-exposed group and the mice kept at 22°C. This indicated that BAT activation did not result in cellular changes, such as changes in cell size or number of mitochondria, that would alter the small-angle scattering signal