Nuclear Medicine

Nuclear Medicine

  • Gran Badshah added an answer:
    Which softwares are able to replace a voxel value by another one in a SPECT acquisition ? (files in DICOM format)
    i.e.: replace some hot spots (> X counts/vol unit) by a mean value.
    Gran Badshah · Universiti Malaysia Pahang

    Hi dears, please can any one help me how to write watermarked frames to a DICOM image back to hide watermarks to be ready for communication?

  • Ronnie C Mease added an answer:
    Does anyone have good comments about Cell tracking with nanoparticles or radiolabeling the cells?

    Does anyone have good comments about Cell tracking with nanoparticles or radiolabeling the cells?

    Ronnie C Mease · Johns Hopkins Medicine

    In-111 oxine and Tc-99m HMPAO are two radiopharmaceuticals that are used clinically to tag white blood cells ex-vivo for reinjection into patients. There are commercial cell membrane intercalating dyes that can be used for optical imaging. There are numerous radiolabeled cell membrane intercalating dyes and phospholipid analogs that also can tag cells. All of these methods have pros and cons which will depend on your particular application.

  • Lina Jia added an answer:
    Why will 18F- combine with the Al-NOTA complex instead of combining with free Al3+? And why 18F- is not free in [18F]AlF complex?

    Why 18F- will combine with the Al-NOTA complex instead of combining with free Al3+ in the method for 18F-labeling of peptides using [18F]AlF (aluminum fluoride) complex formation with 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA) derivatives? And why 18F- is not free in [18F]AlF complex?


    Thanks ! I have learned a lot.

  • Arjyabrata Sarker added an answer:
    What is the difference in parathyroid hormone (PTH) suppression activity between Calcium Carbonate and Calcium Citrate?

    As we know the intake of calcium supplement gradually improves the plasma calcium level and thus suppressing parathyroid secretion. Is there any definite value in what extent calcium carbonate and calcium citrate varies in view of PTH suppression?

    Arjyabrata Sarker · Jahangirnagar University it, though calcium citrate has a better absorption profile than carbonates for its chemical nature, which may tend to an additive benefit.

  • Teik Hin Tan added an answer:
    Should Cardiac SPECT or coronarography be performed first to distinguish coronary disease?

    Nuclear medicine physicians and cardiologist have disagreement in time of application of cardiac SPECT and coronarography in cases suspected for coronary disease.

    Nuclear physicians consider that cardiac SPECT is one non invasive method with very high efficiency for detection of coronary disease.

    Cardiologists consider that cardiac SPECT is not sufficient for detection of coronary disease and prefer coronarography as first diagnostic method   

    Teik Hin Tan · National Cancer Institute, Malaysia

    As far as I understand, the current trend of  cardiovascular imaging is not to detect stenosis only, but the test must be able to stratify the future CV risk and guide invasive intervention. Many trials have shown that critical stenosis >50% detected by CT angiography does not translate to ischaemia. Therefore, stress-imaging such as SPECT/ PET, stress echo and stress MR, plays an important role in risk stratification in the intermediate groups. For low risk group, exercise stress test is enough. CT + FFR are still new and need more data. Please refer to the guidelines:

    2013 ESC guidelines on the management of stable coronary artery disease. European Heart Journal (2013) 34, 2949–3003

    ACCF/AHA/ASE/ASNC/HFSA/HRS/SCAI/SCCT/SCMR/STS 2013 multimodality appropriate use criteria for the detection and risk assessment of stable ischemic heart disease. J Am Coll Cardiol. 2014 Feb 4;63(4):380-406.

    Clinical DecisionMakingWithMyocardial Perfusion Imagingin Patients With Known or Suspected CoronaryArteryDisease. Semin Nucl Med (2014) 44,320-329

  • Teik Hin Tan added an answer:
    Can anyone share with me their experience in paediatrics dose of radioiodine treatment in differentiated thyroid cancer?

    I tried to use the few suggestion of peadiatrics dosing of RAI treatment in the ATA and EANM guidelines. I realised that there was a wide range of dosing after using those suggestion. Please help. Thank you. 

    Teik Hin Tan · National Cancer Institute, Malaysia

    Thanks Dr Lena. We have quite a number of patients in this age group. And, I do agree on giving radioiodine if tumour is >1.0cm. Because, in my experience, almost all patients demonstrated metastasis either lymph node or lungs on our first initial radioiodine whole body scan. They all received radioiodine treatment. Some responded but some were not that lucky. But, both of the two groups were well during follow up until adulthood. It seems likely that radioiodine improves survival outcome in these two groups. Anyway, these patients usually have very good prognosis and long survival whether metastases or not. So, it is very difficult to carry out such cohort.

  • Negri Roberto added an answer:
    Is it possible to conjugate DOTA with DOX (doxorubicine) and under which condition?
    Bioconjugation of bifunctional chelate DOTA with DOX.
    There is increasing interest in the bio-conjugation of peptides and antibody with bi functional chelating agent (DOTA, DTPA), used for RRNT and RIT.

    Is it possible to conjugate DOTA with DOX (doxorubicine) and under which condition?
    Negri Roberto · Amedeo Avogadro University of Eastern Piedmont

    It depends what functional group of DOX you want to use to make the bond... If the amino group is your choice, then you just need to use your DOX with any DOTA-like compound with a functional group that reacts with amines (DOTA-SA or DOTA with isothiocyanate mojety). You could find protocols for these reactions in the literature

  • Madhur KUMAR Srivastava added an answer:
    What is the lowest applicable activity with the earliest imaging time for sentinel node biopsy for breast cancer?

    Research for "easy to do Nuclear Medicine with low dose culture"

    Madhur KUMAR Srivastava · Jawaharlal Institute of Postgraduate Medical Education & Research

    Usually for sentinel node biopsy with surgery to be done same day, 20 MBq is adequate and should be injected at least 2 hours before the surgery. If surgery is planned the next day , then 37-100 MBq is recommended.

    It depends on center to center on type of injection, usually we prefer peri-areolar as peritumoral lymphatics may be heavily laden with tumoral cells so that lymphatics might not flow leading to failure of technique. Peri-areolar injection concept has come up because of unique nature of superficial lymphatics of breast (Sappy plexus).

    Imaging before the surgery, again varies between various centers depending on the time at your disposal. In many busy centers, they do not do imaging and send the patient directly for surgery, but in my opinion, we should do planar imaging and in doubt SPECT- CT for confirmation.

    During surgery, with the use of gamma probe, the injection site is marked and any node having more than 10% of injection site count is considered as positive. This should be taken out for frozen section. Again whole axilla should be surveyed for activity and same principle of 10% should be followed till we do not find anything more than background.

    Hope this would help...Best of luck

  • Jacek Koziorowski added an answer:
    Is it feasible to couple sestamibi (nuclear medicine) with magnetic particles?
    If so, any suggestions on how to couple them?
    Jacek Koziorowski · University Hospital Linköping

    If you look on the structure of sestamibi; a small microsphere - and want to coulpe it to a SPION - my guesstimate is that the biological property of Sestamibi (a MPI agent) will be lost. It is like attaching a car to a corn flake and hope to use it in the cereal for breakfast.

  • After injecting 99mTc-MIBI how much activity (MBq/ml or mCi/ml) is absorbed by a typical myocardium at peak absorption?

    As far as I know, within several min after injection activity absorption would be in the highest value possible. What is "the" value in (Mbq/ml or mCi/ml) ?

    F. Javier de Haro-del Moral · Hospital Universitario Puerta de Hierro-Majadahonda

    The uptake in myocardium in only 2-3%

  • Rame Miftari added an answer:
    What are the advantages of cardiac dynamic SPECT imaging over static (conventional) SPECT imaging?

    In some papers they say dynamic SPECT provides a better contrast between normal and decreased flow regions than can be obtained from static imaging. what are the other advantages,if any?


    The advantage of cardiac dynamic SPECT imaging over conventional SPECT imaging is that cardiac dynamic SPECT imaging allow to estimate the absolute kinetic parameters of left ventricle.
    Dynamic SPECT didn't mean "gated SPECT". In dynamic SPECT the data are collected in time of dose administration.

  • Hanno Krieger added an answer:
    Why internal dosimetry in nuclear medicine is not taken as seriously by doctors as in radiotherapy?
    Prof. Dr. Ljungber, Dr. Stabin, Dr. Flux, Dr. Celler, Dr. Simpkin, Dr. Zazonico, Dr. Sgouros, Dr. Cremonesi, and many others Authors published a lot of papers, softwares, etc. Even so, very few centers apply internal dosimetry for nuclear medicine therapy. Why?
    Hanno Krieger · retired from Justus-Liebig-Universität Gießen

    Most has been said. I just want to show my experience. If you try to calculate doses, organ doses and especially effective doses, you must exactly know the volume and tissue of distribution. This issue is quite impossible, because each patient shows his own metabolism, anatomy and radio nuclide distribution. 

    Therefore doses are normally calculated by human models with standardised persons. The results can just give some ideas of the radiation exposition of the patients.

    A short remark to the diagnostic use of 131-Iodine. It´s completely out and has been substituated in mots cases to 99m-Tc compounds, which serve in same quality but minimize the dose to the patient. The same holds for 201Tl, it´s replaced for cardiac test by 99mTc (MIBA).

  • Alejandro sanchez crespo added an answer:
    In PET images, with the current methods of reconstruction, it is still a necessary denoising step?
    If so, what is the most common method for denoising?
    Alejandro sanchez crespo · Karolinska University Hospital

    Not necesary. One can use different filtration methods or even more advance techniques like waveletes but in clinical routine we do not denoise PET images before reconstruction.

  • Stephan Nekolla added an answer:
    What are the real values of cardiac kinetic parameters washin(k1) and washout(k2) for a normal myocardium?

    When using a two compartmental model

    Stephan Nekolla · Technische Universität München

    In addition to the aforementioned complexities, K1 varies vastly for different (radio)-tracers which are linked to the clinical target, namely the myocardial blood flow - if one uses the Renkin-Crone equation  K1 = E*MBF, E = (1-exp(-PS/MBF)). In other words, for a normal MBF of 0.8, K1 could be 0.8 for 15-O water, 0.75 for N-13 ammonia or 0.5 for 82-Rb (numbers gut feeling...) - depending on the extraction fraction (E) of the particular tracer.

  • Atena Aghaei added an answer:
    What is the lowest applicable activity with the earliest imaging time for sentinel node biopsy for breast cancer?

    Research for "easy to do Nuclear Medicine with low dose culture"

    Atena Aghaei · Mashhad University of Medical Sciences

    we use about 20 MBq for the same day surgery , peri-areolar, intradermal injection, near the tumor side, and we have had good results.

  • Dirk Rattat added an answer:
    What is the acceptable volume (in ml) of Technetium-99m that can be administered to rats?
    I want to tag my extract with technetium-99m and administer it in to the rats tail vein for bioavailability study in rats, but i am finding it difficult to know the volume to administer to the rats.
    Dirk Rattat · Umicore

    Minor remarks:

    "I want to use Tc-99m for Imaging as well as "cut and count assay". is it possible?"

    Perfectly possible. For a reliable procedure make sure not to loose urine, e.g. during scanning (tissues to collect it). Especially when injecting higher volumes, this may happen frequently and can ruin results.

    If the Tc-99m activity of your sample is too low, you can always consider concentrating (depending on the labelled molecule e.g. with spin colums when working with bigger labelled molecules) rather than increasing the volume to inject.

    (Finally, don't forget to have an eye on the pH of your solution, but that's clear anyway.)

  • Yónatan Calderón Pérez added an answer:
    Can multiple radio-labeled probes be used at the same time for PET imaging?
    If different isotopes (11-C, 89-Zr, 64Cu) are used to label different antibodies, can they all be used at the same time during PET imaging? Or because all of them undergo Beta+ decay and produce Gamma rays, is it not possible to distinguish between signals coming from the different probes?
    Yónatan Calderón Pérez · Autonomous University of Barcelona
    Hi Virginia.

    In the case of PET, as many of my coleages pointed out, it is not possible to distiguish the gamma photons emited by the different radiotracers. The reason is that all of them share the same energy (511 keV).

    In the case of SPECT it may be possible. But in most of the cases, it is not. The reason is the energy resolution of the scintillator crystals (>10% FWHM). This low energy resolution does not allow to discard scatter events which can amount up to 50% of your signal (and that is using a single radiotracer, imagine using multiple).

    By using semiconductor detectors (Ge,Si,CdTe,...) it is possible to distinguish radiotracers with different energies and use them simultaneously in the case of SPECT or Compton camera.

    Here is a link to an article of the 2007 IEEE NSS/MIC conference where multiple radiotracers are used simultaneously with a mouse. The scanner is a prototype Compton camera.
  • Manish K. Mishra added an answer:
    Why is Radon-222 itself a gas but its decay products solids?
    see above
    Manish K. Mishra · Department of Atomic Energy
    Radioactivity is a nuclear phenomena. It is number of protons in the nucleus which decides the 'State' of that element. An element can naturally exist in Solid, Liquid or Gas state. So, if by any means the number of protons in the nucleus varies ( be it by Alpha or Beta emission or by EC), the state of the element can also vary. Solid elements can change into Gas/Liquid or Gaseous ones into Solid/Liquid by radioactive transformation.
  • Carl A Wesolowski added an answer:
    What is the value of predictions in nuclear studies?
    Monte Carlo simulations to predict experimental data in the costly nuclear experiments!
    Carl A Wesolowski · University of Saskatchewan
    For modeling in general, one has data, and in some sense application of a model to the data extracts features from that data that have should have physical meaning. If we have done everything correctly, the difference between the model and the data should be at the noise limit of the data. It is generally assumed that models that have less than 10% relative error of fitting are good models, although frankly, noise levels are closer to 1% for nuclear studies, and most models are not very good ones.

    Concerning prediction, a very good model has predictive ability only if it has been designed for the prediction of a particular thing. This may seem somewhat confusing. Let us consider ordinary least squares in y of a functional model of concentration in time to some data. If we have measurement time intervals that are exact and invariant, like 1, 2, 3, 4,,,,n-1,n minutes, then we can predict the n+1 st concentration without regression error, and the only error would be modeling error and data noise. However, if we measure concentrations at unequal time intervals, like 5, 7, 11, 20, 23, 30,,,n-1,n. Then ordinary least squares regression yields a prediction tor concentration at the n+1 time that is too large, and the regression equation slope will be too shallow.

    There are many other examples of error types. Consider for example, that we may not be modeling what we think we are. If we model concentration of a bolus IV injected agent, it is common to assume that we are modeling concentration by ordinary least squares fit of an exponential decay function to that concentration.

    The first error results from the concentration being zero initially, but our model, the exponential decay, is maximum at that time. It would be better to model the concentration as the convolution of a vascular model and a parenchymal model, which then allows one to have both Cobs(t=0)=0 for the concentration and C(t=0)=maximum for the parenchymal model.

    The second error results from assuming an exponential shape where no such thing occurs. An exponential shape does not conserve mass. It comes from C'(t)=-CL*C(t), which is incorrect since C'(t) not only clears (CL) but also dilutes in parencyhmal fluid, and so if the clearance is only renal, then M'(t)=-CL*C(t), which latter is the urinary definition of clearance, and C'(t)>M'(t) leading to inflated CL values, which are even more inflated when there is excess fluid, i.e., when parenchymal fluid is increased in amount.

    Suppose we want to fit this concentration data to find clearance, how do we fit it? As it turns out ordinary least squares would do a poor job of measuring clearance, better would be to use weighted least squares where we minimize Norm[{k*Cobs(t)-C(t)}/{k*Cobs(t)}, best would be to minimize SD(CL)/CL. i.e., it is best to minimize the error of the quantity we wish to measure. Next, it is better to use a fit function that has a shape parameter rather than a fixed, incorrect shape, i.e. a gamma variate rather than an exponential.

    Fine suppose that gets us clearance. Does it get us a model for concentration? No, a concentration model would a convolution of a vascular first pass model, like a gamma distribution and a parenchymal impulse response like a different gamma distribution. Such a model would be expected to match concentration to approximately the level of the noise in the data, e.g., 1%. But, it would not be a model of Clearance. Only the second part of it, the parenchymal impulse response would relate to clearance.

    In summary: 1) The art of finding answers in data is often an inverse problem requiring extensive use of numerical methods chosen for definite reasons, and not chosen by reason of the accidental familiarity to the reader of such methods.
    2) Physical equations must be used, like those that conserve mass, have correct units that balance.

    Using these above principles, predictions and extrapolations can be made accurately, if that is made the explicit purpose of modeling. To do so, requires enough numerical tools in the hands of the modeler, that the correct ones can be discovered by a combination of theory and goodness of fit testing. Moreover, it can take years to solve any single problem type, and there are too few reviewers who can even read the results of such material.
  • Joern Nybo Fog added an answer:
    Where to find a new state of the art nuclear medicine department?
    I have a project establishing a new state of the art nuclear medicine department inclusive at new radiopharmaceutical laboratory and a clean room for blood labeling. The department will have 3 PET/CT, 3 SPECT/CT, 1-2 dedicated cardiac gamma camera and 1 mobile gamma camera.

    The department will have about 30 employees technicians, physicians and a physicist.
    So my question is, does anyone know where to visit a modern, state of the art and productive nuclear department?
    Joern Nybo Fog · Medical Institute, Region southdenmark
    Than you Marco, Swen, Willy and Niels.
  • Radu A. Vasilache added an answer:
    Is nuclear medicine beneficial in the long period?
    For quick recovery we are using nuclear medicine. Experts should handle otherwise these technologies are more harmful than beneficial.
    Radu A. Vasilache · Canberra Packard CE GmbH
    Nuclear medicine is not really used for quick recovery. It is used in two instances:
    1. for diagnostic (SPECT, PET, old fashioned scintigraphy...), and it is used because some of the techniques are simply the best way for identifying a condition
    2. for therapy of cancer, when we speak about metabolic radiotherapy, but this is not leading to quick recovery.
    For the diagnostic, the doses are higher than in classic radiology, but to the best of my knowledge there is no evidence that SPECT or PET investigations resulted in increased incidence of secondary cancers.
    For metabolic radiotherapy, the dose is lower than when using external radiotherapy and even much better localised and targeted, so in fact it saves dose to the patient.
    Summing all this, I would say developing a nuclear medicine program saves lives, either through precise diagnostic or through therapy.
  • Maria Lyra added an answer:
    Does anyone know how to obtain the S factors tables for S factors for 67Ga, 111In and Holmium 166?
    The new version, not the one which was calculated in 1975 and printed in MIRD Pamphlet11.
    Maria Lyra · National and Kapodistrian University of Athens
    Try the http://www.doseinfo-radar.comor Olinda or the older one mirdose 3.1 and you can calculate S
  • Grant Hardy added an answer:
    How to calculate %ID/Pixel?
    I'm confused about the calculation of %ID/Pixel. Most papers said the animals should be sacrificed and the organs be taken out into a r-counter for calculating the %ID. Is there another way which uses a standard radiological source near the animal during the scans to substitute the in-vitro organ measuring after the sacrifice of the animal ?
    Grant Hardy · Shanghai Jiao Tong University
    Thank you very much! How do you think about the method of the article "Tumour uptake of 57-cobalt-bleomycin in patients with breast cancer"(PMID: 7678495)? The author calculates the %ID/Pixel as ROI's counts/minutes/pixel/ID. I'm eager to get your reply.
  • Jim F Malone added an answer:
    What is the period of discharge of patients receiving Iodine131 for thyroid therapy?
    Patient Discharge periods.
    Jim F Malone · Trinity College Dublin
    The issue of releasing patients after radio-iodine therapy is comprehensively reviewed in an IAEA publication:
    Release of Patients from hospital following radionuclide therapy. IAEA Safety Report Series No. 63 2009.
    It can be accessed and downloaded at:
    There are very large differences between countries. The big divide is between the US and the rest of the world. In the US system, patients even with very large doses can be discharged immediately.

    The best documented counterpoint to this is in the European Union where, even with relatively small doses for thyrotoxicosis, the patient may still be detained. In most cases the decision to release a patient is based on some measure of retained activity that is relatively crudely determined. Different countries have different release levels even in the EU. This gives rise to "radioiodine tourism" where people may travel to neighbouring countries for therapy to avail of less stringent release regimes.
  • Saeed Shanehsazzadeh asked a question:
    Why magnificent uptakes of dextran coated NP happened in the RES?
    More than 65 percent of ID's were taken up within 15 post injections of the Liver.
  • ragıp Kayar added an answer:
    Can anyone help me to find a research tool to assess discomfort when performing ROLL (radionuclide occult lesion localisation) rather than pain?
    I am going to assess the patients discomfort while performing ROLL and compare it to wire guided localisation.
    ragıp Kayar · Private Outpatient Breast Clinic
    Dear Mercieca,
    you can compare following items in your study:
    a-The duration of procedures(under local and/or general anesthesia and total time)
    b-patient opinion about them:(painstaking,bothering,unacceptable,acceptable,quite acceptable....e.g)
    c-Physician's(user's) opinion about easiness of procedures(difficult,moderate and easy)
    d-the cost of procedures..
    These factors may give better understanding about the discomfort of each modality...
    kind regards
  • Svetlana Agranovich added an answer:
    Can anyone help me with formula for calculating gastric emptying with solid food?
    While doing calculations in a nuclear medicine gastric emptying study, we are encountering a problem of increased retention in third and fourth hour of the study. Decay correction is taken care of.
  • Ramin Sadeghi added an answer:
    Could anyone share his experience in calculating the 99m-Tc-mebrofenine uptake rate to evaluate hepatic function with hepatobilary scintigraphy?
    I would particularly appreciate if anyone could share a template of the spreadsheet he/she uses for the calculations based on the ROI & curves.
    Ramin Sadeghi · Mashhad University of Medical Sciences
    There are many ways to analyse the hepatic function by semi-quantitative methods. Recently, our research center performed an meta-analysis and you can find several methods in the Table 1 of this study.
  • Robert Njoagwuani added an answer:
    Do we need the Society of Nuclear Medicine (SNM) Guidelines? As the survey shows that a good percentage of institutions do not follow them.
    This is a very simple and interesting study, but one wonders how this lack of adherence to the SNM guideline affects the interpretation of a thyroid scintigram especially among the surveyed population.
    Robert Njoagwuani · Mercy University Hospital
    Just to mention that Guidelines are Guidelines, they are recommendations / suggestions and are not strictly binding. Lawyers would tell you that you do not win a suit strictly based on them. Protocols are different as they outline to you what you are expected do during a procedure/study. This is not to relegate the importance of the SNM and like bodies, they are very useful bodies but my argument is you to not base your practice strictly on their guidelines. These Guidelines can be modified to suit different patient or a particular situation during a study.
  • Henry Levenson added an answer:
    Interested in working on computer models for myocardial viability? Any takers?
    There are difficultiies to ascertain myocardial viability. Do you map it based upon electrical conductivity patterns of the heart or upon MRI or photo emission studies such as with nuclear medicine type images?
    Henry Levenson · University of Southern California
    I believe simply labeling something "viable" is inadequate. It has to be evidence based to justify the idea of what is best to define to define myocardial viability using the constraint of a model. However, technology would vary in many parts of the world so some models would be more accurate than other. As you describe, the model could include functional recovery of the myocardium before or after coronary revascularization, ECG, echocardiogram, arrhythmogenity, myocardial response to exercise, image evaluation with nuclear or MRI imaging.
    Essentially, a multivariate model would essentially describe what is myocardial
    viability and would give a a statistical answer to this semantic enigma.
    I would suggest using a retrospective study using data already available in population groups with cardiac disease in humans.

About Nuclear Medicine

A specialty field of radiology concerned with diagnostic, therapeutic, and investigative use of radioactive compounds in a pharmaceutical form.

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