Nuclear Medicine Tests Research Articles

Comparison of planar bone scintigraphy and single photon emission computed tomography for diagnosis of active condylar hyperplasia.

The aim of this study was to compare the reliability and correlations with age and gender of two nuclear medicine tests used for diagnosis of active condylar hyperplasia, namely, planar bone scintigraphy versus single photon emission computed tomography (SPECT). This was a descriptive observational study carried out in 61 patients (38 women and 23 men) clinically diagnosed as having facial asymmetry and suspected unilateral condylar hyperplasia. The patients had both planar bone scintigraphy and SPECT diagnostic imaging as well as reference data of the percentage of (99)Tc(m) MDP (methylenediphosphonate) uptake in the condyle, clivus, and fourth lumbar vertebra (L4), respectively, for SPECT and planar scintigraphy calculations. Radioactive counts were measured per region of interest and the respective ratios were calculated. The age range of the patients was 13-50 years (mean ± standard deviation = 21.16 ± 8.75). The two groups were compared by a nonparametric (Mann-Whitney U test. Uptake percentage and delta values had normal distribution and consequently were compared by a Student t test. A total of 61 anterior planar images and 61 SPECT images were compared. Eight patients presented high uptake in planar bone scintigraphy images (13.11%), while 32 patients (52.46%) had high uptake with SPECT. The prevalence of condylar hyperactivity was higher in women than in men both for right condyle (ratio 4:3) and for left condyle (10:1) and the prevalence was significantly higher for the right condyle. The study indicates that SPECT is more sensitive to identify condylar hyperactivity as compared to planar bone scintigraphy in patients with clinical presumptive diagnostic of condylar hyperplasia.

Patient perspectives on radiation dose: reporting a survey of patient opinions.

With the marked increase in the number of CT scans, nuclear medicine tests and interventional radiological procedures, it is no longer possible to ignore the patients' increasingly vocal question: how much radiation is too much? The Powerful Patient conducted a survey of patient opinions in March-May 2014 to gather patient input for the International Conference on Radiation Protection in Medicine. Patients are eager to work with their physicians and radiology professionals to gather the data needed to answer their very real concerns. They clearly know and appreciate the value of these applications of radiation but want to use them wisely and without long-term consequences.

Cumulative Radiation Exposure from Medical Imaging in Two Hospital Systems – Implications for Medical Record Portability

This study assessed the estimated cumulative effective ionizing radiation dose from diagnostic imaging studies performed on a sample of patients identified in two emergency departments (ED) from different hospital systems over 5 years. A random sample of patients was retrospectively identified from a cohort of patients receiving diagnostic imaging during their visit. All imaging diagnostic studies performed on the sample patients over a five year period were retrieved and assigned an effective radiation dose by a radiation physicist, using published reference tables. During the five year study period there were 13,387 radiological studies performed on 1,243 patients sampled from the two hospitals. The mean cumulative radiation dose per patient in milliseiverts (mSv) was 45.0 (SD ±71.4) (range 0.1-674.6) mSv. There were 150 patients (12%) exposed to over 100 mSv of ionizing radiation over 5 years. Although CT scans accounted for only 25.5% of tests performed, they contributed to over 53% of the entire estimated effective radiation dose to this population. Moreover, nuclear medicine tests accounted for 5.3% of all tests performed but contributed to 29.7% of the total estimated effective radiation. The study identified a substantial number of patients exposed to estimated cumulative effective doses of ionizing radiation that would put them at risk of developing cancer based on the Linear No-Threshold Model. The study demonstrates that it is important for physicians to know how much cumulative radiation exposure from medical imaging their patients have received. This is one more example of the urgent need for medical record portability and information sharing.

Radiation Risk of Lung Cancer Screening

Lung cancer screening with low dose computed tomography (CT) is the only method ever proven to reduce lung cancer-specific mortality in high-risk current and former cigarette smokers. Radiation exposure from annual screening CT examinations and subsequent CT and nuclear medicine testing to further evaluate positive screening CTs is sometimes raised as a reason to avoid screening and is often misunderstood. With all testing, there are potential benefits and risks. As we sit on the brink of widespread adoption of lung cancer screening CT, we aim to explain why the risks associated with radiation exposure from lung cancer screening are very low and should not be used to avoid screening or dissuade individuals who qualify for screening CT to participate in a lung cancer screening program.

Pediatric nuclear medicine and pediatric radiology

To improve clinical practice is our daily duty as specialists in radiology and in nuclear medicine. When a clinician asks us to perform an imaging examination, we have to advise that clinician about the best test or imaging strategy to study the clinical problem. Risk-to-benefit ratio and the ALARA principle have to be weighed, as well as modality and cost. Hybrid imaging is now the standard in nuclear medicine. The use of multimodality cameras such as SPECT/CT, PET/CT and PET/MR has been revolutionary [1–4]. The key is finding the exact location of functional or metabolic lesions. But adding CT increases the dosimetry [5–7], requires more detailed knowledge of imaging anatomy and depends on collaboration between radiologists and nuclear medicine specialists. The level of expertise among imaging specialists (at least in pediatric nuclear medicine) varies too much. In some countries nuclear medicine is an independent specialty, and in other countries radiologists are in charge of nuclear medicine tests. Physicians-in-training in radiology and in nuclear medicine have to receive multimodality training [8–12]. And continuing education in both specialties is vital to ensure that senior specialists are well-versed in the latest techniques. In any case, imaging specialists must be able to discuss the options with referring clinicians and to advise them on the appropriate technique for each clinical situation. Pediatric nuclear medicine can be performed in general nuclear medicine facilities or in dedicated pediatric nuclear medicine departments. The quality of the images has to be diagnostically excellent in pediatric nuclear medicine but superfluous scans must be avoided and doses must be as low as reasonably achievable and adjusted to each child according to international recommendations [7, 13–16]. These goals can be more easily reached in dedicated pediatric facilities. Dose reduction remains important. Contrary to general opinion the radiation dose of most nuclear medicine scans is lower than that of many comparable radiologic studies. The most typical example is abdominal CT, which has a higher dose than the most frequent nuclear medicine studies. Another example is that two-thirds of the radiation dose from PET/CT is from the CT component [12–14]. In the latter case it is possible to perform a diagnostic CT scan during the PET/CT examination rather than a separate diagnostic CT scan. Or a lower-dose CT scan could be performed in a patient who has recently undergone a diagnostic CT scan. The best option for the future in pediatric oncology, however, is PET/MR. In bone scintigraphy or an MIBG scan, performance of an SPECT/CT scan significantly increases the radiation dose [15–17]. A possibility is to use a lower-dose nondiagnostic CT scan in these cases. And the best practice is to report together with the radiologist, comparing the SPECT and the CT or MR images frame-by-frame. In many papers, correlative analysis of PET/CT images in children has been reported to be superior to separate analysis of CT and FDG/PET images. The term “correlative imaging” is the joint interpretation of different imaging modalities – CT, MR, US and scintigraphy [18]. This is the best example yet of why collaboration between radiologists and nuclear medicine physicians is so important.

Nuclear Medicine Tests for Acute Gastrointestinal Conditions

Acute cholecystitis (AC) and lower-gastrointestinal (GI) bleeding are 2 emergencies commonly encountered in nuclear medicine. Evidence of AC on hepatobiliary scintigraphy (HBS) allows for confident diagnosis and provides support for definitive surgical treatment. Proper patient preparation is essential for HBS including fasting and the use of pharmacologic adjuncts is sometimes required. Pharmacologic adjuncts may also be administered during HBS to shorten the length of the examination and increase its specificity. In the interpretation of HBS, there are several sources of false-positive results to be aware of, most commonly chronic cholecystitis. False-negative results on HBS are usually the result of mistaking another structure, such as a dilated cystic duct, for the gallbladder. Abdominal ultrasound is the appropriate initial test in patients with suspected AC, but HBS is an excellent second tier test for the diagnosis of AC in the work-up of indeterminate cases by sonography. GI bleeding scintigraphy plays an important role in the evaluation and management of patients with acute lower-GI bleeding. Scintigraphy serves to localize sites of active GI bleeding and stratify those patients who would benefit from aggressive treatment (surgery or arteriography) vs those who can be managed medically. Pretest involvement of respective services is critical for successful bleeding site confirmation and therapy by interventional radiology or surgery or both. Single photon emission computed tomography/computed tomography erythrocyte scintigraphy has demonstrated superior accuracy and precision over planar scintigraphy in the diagnosis of acute GI bleeding. Additionally, single photon emission computed tomography/computed tomography scintigraphy of GI bleeding provides useful supplemental anatomical information that benefits patient management.

A Clinician's Guide to Nuclear Oncology: Practical Molecular Imaging and Radionuclide Therapies

N.P. Alazraki, M.J. Shumate, and D.A. Kooby Reston, VA: Society of Nuclear Medicine and Molecular Imaging, 2007, 206 pages, $39 A Clinician’s Guide to Nuclear Oncology was written to educate clinicians about the types of nuclear medicine tests and treatments that are available for specific

FDA Approves Radioactive Drug to Help Assess Cognitive Decline

Back to table of contents Previous article Next article Clinical & Research NewsFull AccessFDA Approves Radioactive Drug to Help Assess Cognitive DeclineLeslie SinclairLeslie SinclairSearch for more papers by this authorPublished Online:1 Jun 2012https://doi.org/10.1176/pn.47.11.psychnews_47_11_23-bAbstractPhysicians will soon have a new tool to help them evaluate patients with cognitive decline who might have Alzheimer’s disease. The Food and Drug Administration (FDA) announced April 10 the approval of Amyvid (florbetapir F 18 injection), a radioactive drug that binds to brain beta-amyloid. Amyvid will be available from Avid Radiopharmaceuticals, a subsidiary of Eli Lilly and Company.Following intravenous injection, Amyvid can be detected by positron emission tomography (PET) to produce images of the amyloid neuritic plaques in the brains of individuals who are being evaluated for Alzheimer’s disease and other causes of cognitive decline.A negative Amyvid scan indicates few to no neuritic plaques and reduces the likelihood that any cognitive impairment is due to Alzheimer’s. A positive scan indicates moderate to frequent plaques, an amount that can be found in patients with Alzheimer’s, patients with other types of cognitive impairment, and older people with normal cognition.In a press release announcing the FDA’s approval of Amyvid, Eli Lilly was careful to note that Amyvid is not being touted as a diagnostic test for Alzheimer’s: “Amyvid is an adjunct to other diagnostic evaluations. A positive Amyvid scan does not establish a diagnosis of Alzheimer’s disease or other cognitive disorder. Additionally, the safety and effectiveness of Amyvid have not been established for predicting development of dementia or other neurologic conditions or monitoring responses to therapies.”Despite those limitations, Amyvid is likely to be a valuable addition to physicians’ armament for evaluating signs of Alzheimer’s, a disease that can be definitively diagnosed only by postmortem pathological exam.“Many Americans undergo evaluations to try to determine the cause for a decline in cognitive functioning,” said Janet Woodcock, M.D., director of the FDA’s Center for Drug Evaluation and Research, in a press release announcing Amyvid’s approval. “Until now, the brain content of beta-amyloid neuritic plaques could only be determined with a brain biopsy or examination of the brain at autopsy. This imaging agent is one tool to help physicians in the assessment of their patients by serving as an adjunct to other diagnostic evaluations.”Positron emission tomography units like this one will be used to detect the distribution of Amyvid in the brains of patients with cognitive decline.Jens LangnerAmyvid’s journey to FDA approval has not been without controversy. When Avid Radiopharmaceuticals researchers published the results of their study of florbetapir F 18 in the January 19 JAMA, concluding that their work provided evidence that a molecular imaging procedure can identify beta-amyloid pathology in the brains of individuals during life, critics argued that the researchers withheld critical data from the journal that showed substantial variation in the interpretation of the PET scans from one reader to the next.In a statement at the time of the drug’s approval, Eli Lilly said it had “worked collaboratively with the FDA and nuclear-medicine experts to identify the appropriate ways to support accurate and consistent interpretation of Amyvid scans by physicians. These efforts resulted in the development and validation by Lilly of both an online and in-person reader-training program for physicians using Amyvid.”Lilly cautioned that Amyvid images should be interpreted only by readers who have successfully completed Amyvid reader training and that errors may occur in the estimation of plaque density during image interpretation.The FDA reiterated those cautions to the general public, saying, “This is a new type of nuclear medicine test, and images should be interpreted only by health care professionals who successfully complete a special training program developed by the manufacturer.”The availability of Amyvid may be limited initially. Because Amyvid loses over half of its radioactivity every two hours, it must be distributed directly from a radiopharmacy to the imaging centers where it will be administered within several hours. According to Avid Radiopharmaceuticals, a limited number of radiopharmacies will be distributing Amyvid beginning this month, with the goal of making the product available in more areas as soon as possible. An abstract of “Use of Florbetapir-PET for Imaging Beta-Amyloid Pathology” is posted at http://jama.jamanetwork.com/article.aspx?articleid=645188. ISSUES NewArchived

A Call to “Image Gently”

In August 2011, The Joint Commission (2011) issued a sentinel event alert discussing how high-radiation dosages delivered at any one timemay cause a risk and long-term injury to patients. This has been a particular concern for pediatric patients for many years. In a study by Brenner, Elliston, Hall, and Berdon (2001) in the American Journal of Roentgenology, concern was raised about the possible induction of added cancers because of the ionizing radiation of children undergoing computed tomography (CT). More recently, Brenner and Hall (2007) published that up to 2% of all cancers in theUnited States could be because ofCT radiation exposure. Although many experts disagree on the extent of cancers that may occur from diagnostic imaging, we, as pediatric nurses, should be aware of the possible risk to our patients and the need to provide education to their caregivers. Radiation is found all around us, and we have been exposed to radiation since we were born. Radiation occurs naturally; we are laid bare to these background sources daily as we breathe air (radon gas), ingest food that has absorbed trace radioisotopes, such as potassium, and absorb particles through means of cosmic bombardment. Artificial sources of radiation can either be from nonionizing radiation, such as the type that is used in cell phones or microwaves, or from ionizing radiation used in medical imaging (International Atomic Energy Agency, 2011). Since the creation of CT scans in the early 1970s, the number of ionizing studies have risen from 2 million studies per year to more than 72 million completed in the United States during 2007 (National Council on Radiation Protection, 2009). CT scans are essential for the diagnosis of certain conditions in children such as appendicitis, head injuries, multiple trauma, and congenital heart defects (Frosh, 2011). However, it is the call of the medical community to determine whether a CT scan is necessary. If the medical

핵의학 일반영상 검사업무 오류개선 활동에 따른 환자 만족도

핵의학과에서 시행되는 일반 영상 검사는 수검자의 검사 접수로부터 의사의 판독까지의 과정 동안 오류가 발생된다. 이러한 오류는 최종단계인 의사 판독 시에 확인되어 재검사나 추가촬영, 결과의 재분석, 그리고 PACS 영상의 수정등의 내용을 영상실 검사 담당자에게 지시한다. 이러한 과정을 거쳐 얻어진 결과는 검사에서부터 판독까지의 시간 지연을 초래하고 또한 추가검사가 발생될 경우 환자 만족도와 병원의 신뢰도가 하락하게 된다. 따라서 영상 검사의 접수부터 결과 확정까지 발생되는 오류를 개선하여 수검자들의 불만 감소에 따른 환자 만족도 증가와 근무자들의 업무 효율 증가를 목적으로 한다. 2008년 3월부터 12월까지 9개월간 서울아산병원 핵의학과 일반 영상 검사를 하는 수검자의 검사 오류를 분석하여 2009년 1월부터 12월까지 12개월간 1차 개선 활동으로 검사 절차서의 재 확립 및 검사 업무기술서 작성, 2010년 1월부터 6월까지 6개월간 2차 개선 활동으로 Pre-filtering & Post-Filtering, 2010년 7월부터 10월까지 3개월간 3차 개선 활동 Cross-Check와 스티커 제작 및 부착 실시 이후 검사 오류 건수를 수집하여 비교하였다. 연도별 오류 건 수는 92건에서 1차, 2차 개선 후 32건, 3차 개선 후 46건으로 나타났고, 검사자에 의한 오류는 전체 오류원인의 94.6%이던 것이 74.3%로 감소되었다. 핵의학 일반 영상 검사는 다양한 검사의 종류와 서로 다른 전처치 및 결과산출, 영상의 구성, PACS 전송 영상의 차이로 인하여 검사자의 실수가 발생될 가능성이 높기 때문에 이를 줄이기 위한 개선 활동이 지속되어야 하며 각 영상실 담당자들의 지속적인 Cross-Check와 판독실의 Confirm 과정을 통하여 개인별 편차를 줄여나가야 할 것이다. To n the field of nuclear medicine, with regard to checking regular patients, from the moment they register up to the doctor's diagnosis, the person in charge of the checks can find errors in the diagnosis, reexamine, reanalyze the results or save images to PACS. Through this process, the results obtained from the readings are delayed due to checks and additional tests which occur in hospitals, causing patient satisfaction and affected reliability. Accordingly, the purpose is to include visual inspection of the results to minimize error, improve efficiency and increase patient satisfaction. Nuclear medicine and imaging tests from examines at Asan Medical Center, Seoul, from March 2008 to December 2008, were analyzed for errors. The first stage, from January 2009 to December 2009, established procedures and know-how. The second stage from January 2010 until June 2010 conducted Pre-and Post-filtering assessment, and the third stage from July 2010 until October 2010 consisted of cross-checks and attaching stickers and comparing error cases. Of 92 errors, the 1st, 2nd and 3rd stage had 32 cases, and there were 46 cases after the 4th stage, with the overall errors reduced by 74.3% from 94.6%. In the field of general nuclear medicine, where various kinds of checks are performed according to the patient's needs, analysis, image composition, differing images in PACS, etc, all have the potential for mistakes to be made. In order to decrease error rates, the image can continuously Cross-Check and Confirm diagnosis.

High resolution SPECT imaging for visualization of intratumoral heterogeneity using a SPECT/CT scanner dedicated for small animal imaging

Tumor interiors are never homogeneous and in vivo visualization of intratumoral heterogeneity would be an innovation that contributes to improved cancer therapy. But, conventional nuclear medicine tests have failed to visualize heterogeneity in vivo because of limited spatial resolution. Recently developed single photon emission computed tomographic (SPECT) scanners dedicated for small animal imaging are of interest due to their excellent spatial resolution of <1mm, but few studies have focused on the evaluation of intratumoral heterogeneity. We investigated the optimal conditions related to high resolution imaging of heterogeneous tumor interiors using a small animal SPECT scanner. The conditions related to SPECT/CT visualization of heterogeneous tumor interiors were investigated using phantoms with (111)In and simulations of actual small animal imaging. The optimal conditions obtained were validated by in vivo imaging of sarcoma 180-bearing mice. Larger number of counts must be obtained within limited acquisition time to visualize tumor heterogeneity in vivo in animal imaging, compared to cases that simply detect tumors. At an acquisition time of 30min, better image quality was obtained with pinhole apertures diameter of 1.4mm than of 1.0mm. The obtained best spatial resolution was 1.3mm, it was acceptable for our purpose, though a little worse than the best possible performance of the scanner (1.0mm). Additionally, the reconstruction parameters, such as noise suppression, voxel size, and iteration/subset number, needed to be optimized under the limited conditions and were different from those found under the ideal condition. The minimal radioactivity concentration for visualization of heterogeneous tumor interiors was estimated to be as high as 0.2-0.5MBq/mL. Liposomes containing (111)In met this requirement and were administered to tumor-bearing mice. SPECT imaging successfully showed heterogeneous (111)In distribution within the tumors in vivo with good spatial resolution. A threshold of 0.2MBq/g for clear visualization of tumor heterogeneity was validated. Autoradiograms obtained ex vivo of excised tumors confirmed that the in vivo SPECT images accurately depicted the heterogeneous intratumoral accumulation of liposomes. Intratumoral heterogeneity was successfully visualized under the optimized conditions using a SPECT/CT scanner.

Diagnostic accuracy of combined 99mTc-sulesomab and 99mTc-nanocolloid bone marrow imaging in detecting prosthetic joint infection

Autologous-labeled leukocytes combined with sulfur colloid bone marrow scan is the current nuclear medicine gold standard for the diagnosis of prosthetic joint infection. The goal of this study is to assess the diagnostic accuracy of a new nuclear medicine modality for detecting infection in this context. Twenty-seven patients with suspicious hip and knee arthroplasties were enrolled prospectively and underwent nuclear medicine testing using 99mTc-sulesomab and 99mTc-nanocolloids sequentially. These results were then crossed with the final diagnosis to determine the test(s) diagnostic accuracy. An isolated 99mTc-sulesomab scan shows 100% sensitivity (0.40-1) and negative predictive value (0.31-1) but only 20% specificity (0.05-0.48). Combining it with a 99mTc-nanocolloid bone marrow scan increases the specificity (0.75-1) and the positive predictive value (0.40-1) to 100%. Furthermore, the combined test has fewer equivocal readings and higher interreader agreement: κ test value 0.59 vs. 0.44. The results support the hypothesis that these technically simpler and ready-to-use products may be an alternative to autologous-labeled leukocytes/sulfur colloid marrow scan.

New American Thyroid Association and American Association of Clinical Endocrinologists Guidelines for Thyrotoxicosis and Other Forms of Hyperthyroidism: Significant Progress for the Clinician and a Guide to Future Research

New American Thyroid Association and American Association of Clinical Endocrinologists Guidelines for Thyrotoxicosis and Other Forms of Hyperthyroidism: Significant Progress for the Clinician and a Guide to Future Research

Biodistribution and radiation dosimetry of the α7 nicotinic acetylcholine receptor ligand [11C]CHIBA-1001 in humans

4-[(11)C]Methylphenyl 2,4-diazabicyclo[3.2.2]nonane-2-carboxylate ([(11)C]CHIBA-1001) is a newly developed positron emission tomography (PET) ligand for mapping α(7) nicotinic acetylcholine receptors. We investigated whole-body biodistribution and radiation dosimetry of [(11)C]CHIBA-1001 in humans and compared the results with those obtained in mice. Dynamic whole-body PET was carried out for three human subjects after administering a bolus injection of [(11)C]CHIBA-1001. Emission scans were collected in two-dimensional mode over five bed positions. Regions of interest were placed over 12 organs. Radiation dosimetry was estimated from the residence times of these source organs using the OLINDA program. Biodistribution data from mice were also used for the prediction of radiation dosimetry in humans, and results with and those without accommodation of different proportions of organ-to-total-body mass were compared with the results from the human PET study. In humans, the highest accumulation was observed in the liver, whereas in mice, the highest accumulation was observed in the urinary bladder. The estimated effective dose from the human PET study was 6.9 μSv/MBq, and that from mice was much underestimated. Effective dose estimates for [(11)C]CHIBA-1001 were compatible with those associated with other common nuclear medicine tests. Absorption doses among several organs were considerably different between the human and mouse studies. Human dosimetry studies for the investigation of radiation safety are desirable as one of the first clinical trials of new PET probes before their application in subsequent clinical investigations.

Development of a Comprehensive Software Application for Calculations in Nuclear Medicine and Radiopharmacy

In the daily practice of in-hospital or centralized radiopharmacies, there is a need to perform reliable numeric calculations. Furthermore, several nuclear medicine diagnostic tests also involve carrying out calculations. In both cases, these calculations are sometimes complex or tedious and prone to error. We report the development of a computer software program that performs a comprehensive range of calculations required in radiopharmacy and nuclear medicine diagnostic tests. This software was developed and compiled in the Visual Basic programming language using algorithms and methods reflected in the scientific literature. We developed 2 versions of the software program, which we call Nucleolab. It automatically performs calculations relating to radiopharmacy practice as well as 9 diagnostic nuclear medicine tests. The 0.1 version performs all these calculations, and the 1.2 version also has a database that enables the user to save and recover diagnostic test results and issue custom reports. The software can be downloaded at www.radiofarmacia.org/nucleolab-english. To our knowledge, ours is the first attempt to develop a comprehensive software application that facilitates calculations in nuclear medicine and radiopharmacy, reducing errors and improving efficiency and accuracy.

TU‐B‐204C‐01: Breast Specific Gamma Imaging

Molecular Breast Imaging is a new modality for diagnosing breast cancer. Screening Mammography has vastly improved over the last 30 years, but radiologists still miss 10% of breast cancers especially in women with dense breast tissue. The use of breast ultrasound and breast MRI has definitely helped radiologists to detect additional cases of breast cancer and to evaluate the extent of breast cancer.There now is a new different test that can be used to solve difficult or confusing cases. It also is an excellent test when MRI is not feasible or available. It is a nuclear medicine test that analyzes cellular activity. Since cancer cells are usually more active than normal cells, they usually will absorb more of the radioactive isotope producing a black (hot spot) on the image.This lecture will explain the underlying physics of the procedure and the technique in using the machine. Examples of real cases will be used to demonstrate how this new test fits in with the more traditional methods of breast cancer detection.Learning Objectives:1. Understanding the physics behind Molecular Breast Imaging.2. Understanding the clinical applications of this test.3. Understanding how this test fits in with Mammography, Breast Ultrasound and Breast MRI.

Application of ICRP-103 in the calculation of effective dose associated to nuclear medicine tests

Objective Re-evaluate the effective dose (E) of typical nuclear medicine procedures using the new ICRP-103 weighting factors and the latest dosimetry data and relate E with Background Equivalent Radiation Time (BERT). Material and methods Effective dose associated with radiopharmaceuticals and nuclear medicine procedures has been calculated for the following ages: adult, 15, 10, 5 and 1 year. Dosimetry data have been extracted from ICRP-106, ICRP-80, ICRP-53 and/or manufacturer's brochure. Results The relationship of the data of effective dose associated with radiopharmaceuticals and explorations is shown. The new tissue weighting factors result in a decreased value of the effective dose, except in cases that particularly affect the breast, in which it increases. The effective dose associated with nuclear medicine procedures is in the range 0.1–60 mSv. BERT ranges from a few days to 20 years. The effective dose associated to tests in children is generally higher than the effective dose for an adult. Conclusions The results shown in this paper are an updated collection of effective dose values for commonly used radiopharmaceuticals in nuclear medicine. Expressing the effective dose equivalent time in units of natural radiation helps to explain issues associated with radiation exposure to patients and healthcare personnel.

Abstract 4325: The requisites for in vivo clear visualization of intratumoral heterogeneity by a SPECT/CT scanner dedicated for small animal imaging

Abstract Objectives: Although even conventional nuclear medicine tests could successfully detect tumor masses in vivo, they did not always visualize heterogeneous interiors of tumor masses. The clear visualization of intratumoral heterogeneity in vivo will give us additional information about the choice of cancer therapy. Recently developed single photon emission computed tomography (SPECT) scanners dedicated for small animal imaging show excellent spatial resolution (&amp;lt; 1 mm) and they are expected to visualize intratumoral heterogeneity in vivo even for mouse tumors. But, little studies have revealed the requisites for this purpose. In this study, we considered the conditions to image intratumoral heterogeneity in vivo. Materials and Methods: A small animal SPECT/CT scanner with four detectors equipped with 9-pinhole collimators (1.0 mm or 1.4 mm of pinholes, Bioscan, Washington, D.C.) was used. First, phantom experiments with 111In of similar radioactivity that is commonly used in mouse imaging studies were performed to evaluate the optimal conditions to obtain best spatial resolution and concentration linearity. Then, mouse tumors were imaged. 111In-labeled liposomes with high specific activity and high concentration were injected to Sarcoma180 bearing ddY mice. In vivo SPECT images and ex vivo autoradiograms were compared and the radioactivity distribution in tumors and other tissues was measured. Results: In phantom experiments with 111In, the best spatial resolution under the current experimental conditions simulating in vivo small animal imaging was 1.1 mm (1.4 mmϕ, 5 MBq/mL, 120 min of total acquisition), although they greatly depended on total acquisition counts or total radioactivity. The good linearity between the concentration and SPECT values was obtained under the condition of 0.5-1.5 MBq/mL. 111In-labeled liposomes (15-20 MBq/mouse) were strongly accumulated in the tumor (1-2 MBq/g, 10-15% of injected dose/g), predominantly in the marginal regions of tumors. And, SPECT clearly visualized this heterogeneous intratumoral localization in vivo with good spatial resolution with the acquisition time of 60 min at 24h after the injection. The threshold to clearly visualize the tumor heterogeneity was about 0.5 MBq/g. Ex vivo autoradiograms of excised tumors demonstrated that the small animal SPECT scanner could successfully image the heterogeneous intratumoral accumulation of liposomes. Conclusion: The SPECT/CT scanner dedicated for small animal imaging successfully visualized the tumor heterogeneity in vivo using radioactive probes with rather high specific radioactivity and high concentration. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4325.

Additive Value of Nuclear Medicine Shuntograms to Computed Tomography for Suspected Cerebrospinal Fluid Shunt Obstruction in the Pediatric Emergency Department

To measure the predictive value of nuclear medicine studies (cerebrospinal fluid [CSF] shuntograms) and radiographic studies (computed tomographic [CT] scans) in a cohort of children undergoing evaluation for suspected shunt obstruction in a tertiary care pediatric emergency department (ED). A retrospective chart review was conducted on patients younger than 18 years who presented to the pediatric ED of the Children's Hospital of Western Ontario and had both CT of the head and a CSF shuntogram ordered by the attending pediatric emergency medicine physician between December 1998 and April 2003 because of suspected shunt obstruction. A total of 69 patients were evaluated for suspected shunt obstruction in the ED during this period with both a CT and a CSF shuntogram. Twenty-seven patients (39.1%) subsequently required corrective surgery for suspected shunt obstruction that was confirmed intraoperatively. The CT scans showed abnormalities suggestive of CSF shunt obstruction in 21 of the patients who required surgery (sensitivity, 77.8%; negative predictive value, 82.4%), whereas the CSF shuntograms showed abnormalities suggestive of CSF obstruction in 25 of the patients who required surgery (sensitivity, 92.6%; negative predictive value, 92.6%). The CT scans and the shuntograms combined revealed abnormalities suggestive of CSF shunt obstruction in 26 of the 27 patients who required surgery (sensitivity, 96.3%; negative predictive value, 97.4%). Over one third of pediatric ED patients evaluated with CT and CSF shuntograms required surgical management. Sensitivity was increased with CT and CSF shuntogram compared with CT alone. Prospective studies are required to assess the use of radiographic and nuclear medicine tests for the shunt evaluation in conjunction with the development of a clinical prediction rule for the pediatric emergency physician.

A Pervasive System for Nuclear Medicine Department

Pervasive Computing technologies can be successfully adopted in designing smart and enhanced healthcare services and applications. Within a typical healthcare institution, one particular facility which can greatly benefit from pervasive technologies is the Nuclear Medicine Department, where nuclear medicine diagnostic tests like PET scan and nuclear scintigraphy are routinely carried out involving the use of radioactive substances. This paper presents a pervasive healthcare system which is intended to support clinicians in handling nuclear medicine test sessions within an appropriate, safety-aware context. The proposed system also includes features to easily interoperate with heterogeneous software and databases already present in traditional hospitals. Its design lies on a methodology which integrates RFID and photoelectric sensor technologies. An experimental prototype has been implemented and tested showing the feasibility of the system in a real healthcare facility.