Search

Oral glucose and intravenous insulin (G/I) loading protocols are commonly used in 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) cardiac viability studies. Although the amount of insulin to be given per blood glucose range has been well described in guidelines, the amount of glucose to be given is not detailed well. In this retrospective study, we aimed to assess if certain parameters, particularly the amount of glucose and insulin given, may affect 18F-FDG uptake in the hibernating myocardium and also determine the problems with this protocol. 18F-FDG PET cardiac viability study with G/I loading protocols was performed in 49 patients. Fasting blood glucose (FBG), amount of glucose given, blood glucose level after glucose load, amount of insulin given, and blood glucose level at the time of 18F-FDG injection were recorded. Statistical analysis was performed to determine if there is any difference in the above values in PET viable and PET nonviable groups and also in subgroups assessing 18F-FDG uptake also in normal myocardium. For G/I loading, we used our local protocol in 43 patients, and other protocols in six. 18F-FDG PET showed viability in 31 patients, and it was negative for viability in 18. In 22 patients, mainly in PET viable group, there was varying degree of reduced 18F-FDG uptake in normal myocardium. There was no significant difference in FBG, amount of glucose given, blood glucose level after glucose load, amount of insulin given, and blood glucose level at the time of 18F-FDG injection in PET viable and PET nonviable groups and also in subgroups. The problems with G/I loading protocol included deciding on the amounts of glucose and insulin given, maximum amount of insulin to be given, handling diabetics, optimal time to measure blood glucose after insulin administration, and interpretation of findings in cases with diffusely reduced 18F-FDG uptake. Further improvements in current guidelines are necessary to obtain images in optimal conditions for accurate results.

The aim of this study is to investigate the relationship between brown adipose tissue (BAT) activation and myocardial fluorine-18-fluorodeoxyglucose ([18F] FDG) uptake in terms of intensity and patterns. The patients were divided into two groups as follows: BAT and control groups. The BAT group consists of 34 cases that showed BAT uptake. The control group, with no BAT uptake, included 68 patients who were matched for body mass index, gender, and season. The scans were retrospectively reviewed by two nuclear medicine physicians who visually evaluated the intensity of myocardial [18F] FDG uptake. The myocardial [18F] FDG uptake was visually classified into the following three patterns: diffuse, heterogeneous, and focal. The regions of activated BAT distribution were noted. The mean myocardial [18F] FDG uptake was 2.50 ± 0.75 for the BAT group and 2.13 ± 0.88 for the control group with a statistically significant difference (P = 0.031). The myocardial [18F] FDG uptake pattern was similar in the BAT and control groups with the diffuse pattern being the most common, followed by the heterogeneous and less commonly focal. In the BAT group, the anatomical distribution of BAT was mainly in supraclavicular, paravertebral, and axillary and to a lesser extent in cervical regions. BAT group had a significantly higher intensity of [18F] FDG myocardial uptake compared to that of the control group. The presence of activated BAT did not affect the pattern of myocardial uptake. Knowledge of these findings may help in understanding the variability of myocardial [18F] FDG uptake and consequently in avoiding misinterpretation of cardiac findings in positron-emission tomography/computed tomography studies.

Understanding the pathophysiology of disease is essential for all who study and work in any field of medicine. Since nuclear medicine deals with functional and molecular changes, it becomes crucial to understand the pathophysiological changes of relevant diseases and disease-like conditions to properly study and practice the field.

Objective: F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) has been increasingly used in myocardial viability imaging. In routine PET viability studies, oral glucose and intravenous insulin loading is commonly utilized. In an optimal study, glucose and insulin loading is expected to cause FDG uptake both in hibernating and normal myocardium. However, in routine studies it is not uncommon to see absent or reduced FDG uptake in normal myocardium. In this retrospective study we further analyzed our PET viability images to evaluate FDG uptake status in myocardium under the oral glucose and intravenous insulin loading protocol that we use in our hospital. Methods: Patients who had both myocardial perfusion single photon emission computed tomography (SPECT) and FDG PET cardiac viability studies were selected for analysis. FDG uptake status in normal and abnormal myocardial segments on perfusion SPECT was evaluated. Based on SPECT and PET findings, patients were divided into two main groups and four subgroups. Group 1 included PET viable studies and Group 2 included PET-nonviable studies. Subgroups based on FDG uptake in normal myocardium were 1a and 2a (normal uptake) and 1b and 2b (absent or significantly reduced uptake). Results: Seventy-one patients met the inclusion criteria. Forty-two patients were PET-viable and 29 were PET-nonviable. In 33 of 71 patients (46.4%) there was absent or significantly reduced FDG uptake in one or more normal myocardial segments, which was identified more in PET-viable than PET-nonviable patients (59.5% vs. 27.5%, p = 0.008). This finding was also more frequent in diabetic than nondiabetic patients (53% vs. 31.8%), but the difference was not significant (p = 0.160). Conclusions: In nearly half of our patients, one or more normal myocardial segments showed absent or significantly reduced FDG uptake. This finding, particularly if it is diffuse, could be from suboptimal study, inadequacy of current glucose and insulin loading protocols, or various other patient-related causes affecting FDG uptake both in the normal and hibernating myocardium. In cases with significantly reduced FDG uptake in normal myocardium, PET images should be interpreted cautiously to prevent false-negative results for viability. Keywords: Fluorodeoxyglucose, Glucose loading, Insulin loading, Myocardial viability, Positron emission tomography

Various positron emission tomography (PET) studies are available for prostate cancer which show various successes at demonstrating primary, recurrent, or metastatic tumor and assessing response to treatment. In this case report, we will present and compare pre- and post-therapy fluorodeoxyglucose, sodium fluoride, and gallium-68 prostate-specific membrane antigen PET images of a patient with prostate cancer.

Objective: The prevalence of coronary artery disease (CAD) is high in patients with diabetes. Because ischemia and infarction are often silent in diabetic patients, diagnosis of CAD occurs inevitably late. It is essential to identify the presence of CAD in diabetic patients to start early treatment. Therefore, the aim of this study was to determine the prevalence of abnormal myocardial perfusion in asymptomatic type 2 diabetic patients using myocardial perfusion imaging. Methods: Fifty-nine patients with type 2 diabetes, who did not have any history of CAD, but did have risk factors underwent myocardial perfusion single-photon emission computed tomography (SPECT) imaging using 99mTc-tetrofosmin and a 2-day stress–rest protocol. Two nuclear medicine specialists independently interpreted the images. Statistical analysis was performed to determine if there is a correlation between the presence of perfusion abnormalities and the history of diabetes (duration of disease, type of treatment, level of control, and presence and type of complications). The influence of other factors such as age, sex, smoking history, and family history of CAD, with abnormal scans were also studied. Results: Of the 59 patients, abnormal scans were detected in 22 (37%) including 16 with reversible defects due to stress-induced ischemia. Hence the prevalence was 37%. Duration of diabetes, use of insulin, nephropathy, and neuropathy were significantly associated with abnormal scans (p = 0.048, p = 0.045, p = 0.006, and p = 0.03, respectively). Additionally, positive family history of CAD was highly associated with perfusion abnormalities (p

Gallium-68 prostate-specific membrane antigen (Ga-68 PSMA) ligand (HBED-CC) is a new promising positron emission tomography (PET) tracer for prostate cancer. Intense renal parenchymal uptake is a physiologic finding on Ga-68 PSMA ligand PET images. Evaluation of kidneys in low intensity demonstrates excellent distribution of this radiotracer in renal parenchyma with excellent image quality and resolution. In this article, we present the Ga-68 PSMA ligand PET renal images of four patients with prostate cancer. In two patients, there is normal distribution of radiotracer, and in other two, there are renal cysts causing parenchymal defects.

Aim This study was carried out to compare the efficacy of Y, Lu, and combination of both radiotracers (tandem) peptide receptor radionuclide therapy (PRRT) in patients with inoperable and metastatic neuroendocrine tumors. Materials and methods Systematic searches of PubMed and SciVerse Scopus databases were performed till December of 2016. The data were categorized into three groups: Y-PRRT, Lu-PRRT, and tandem-PRRT. Each group was subdivided on the basis of the response criteria used: Response Evaluation Criteria in Solid Tumors (RECIST) or Southwest Oncology Group (SWOG) criteria. Disease response and disease control rates of each group were analyzed. Results For the RECIST group, Y-PRRT disease response rates ranged from 22.81 to 56.1%, with a pooled random effect of 42.92%, and the disease control rate was 100%. Lu-PRRT disease response rates ranged from 27.63 to 57.35%, with a pooled random effect of 33.41%, and disease control rates ranged between 71.88 and 100%, with a pooled fixed effect of 79.32%. As for tandem-PRRT, disease response rates ranged between 42.11 and 66.67%, with a pooled fixed effect of 50.52%, and the disease control rate ranged between 93.33 and 100%, with a pooled fixed effect of 98.97%.For the SWOG group, Y-PRRT disease response rates ranged from 5.13 to 26.56%, with a pooled random effect of 13.4%, and disease control rates ranged between 76.56 and 85.9%, with a pooled fixed effect of 80.93%. Lu-PRRT disease response rates ranged from 6.06 to 60.29%, with a pooled random effect of 26.4%, and the disease control rates between 48.48 and 85.29%, with a pooled random effect of 74.53%. Conclusion Y-PRRT had the highest disease control rates under both RECIST and SWOG criteria. Tandem-PRRT had the highest disease response rate in the RECIST criteria, indicating that PRRT should be customized to each patient individually for maximum benefit.

The aim of this study was to correlate the uptake of 99mTc-methoxy-isobutyl-isonitrile (MIBI) with ultra-structural features of parathyroid adenomas. Twenty patients with proven primary hyperparathyroidism were evaluated prospectively. Preoperative double-phase 99mTc-MIBI scintigraphy was performed in all patients and the degree of tracer uptake by the parathyroid lesions was assessed visually and semi-quantitatively. The excised glands were examined histologically and ultrastructurally, and their features were correlated with the degree of the radiotracer uptake. At surgery, 21 parathyroid adenomas were removed (double adenoma in one patient and a solitary adenoma in each of the remaining 19 patients). 99mTc-MIBI scan detected 18 of the 21 adenomas. There was positive correlation between the degree of 99mTc-MIBI uptake and the mitochondrial contents of the parathyroid adenoma cells. Four adenomas with intense uptake had high content of mitochondria in the cells. The three false-negative scans had low-to-moderate mitochondrial content. 99mTc-MIBI uptake is related to the mitochondrial content of the parathyroid adenoma cells.

Objective: The goal of the study was to investigate whether or not gram-negative organisms that secrete antichemotactic factors cause the nonaccumulation pattern of 111In-oxine-labeled white blood cell (111In-WBC) scans. Materials and Methods:Staphylococcus aureus (gram-positive) (group 1) was injected into 25 rabbits and Escherichia coli (gram-negative) (group 2) into another 25 to induce infection in the lumbar vertebrae or left thigh bone (femur). Sixteen successfully infected and surviving rabbits from each group were used for imaging and analysis. Of the 16 rabbits, each group included 8 with vertebral infection and 8 with femur infection. For imaging, each rabbit was injected intravenously with 11.1 MBq (300 μCi) 111In-WBC, and images were acquired 24 h later. Microscopic histopathology was performed after decalcification to confirm osteomyelitis. Results: The 111In-WBC accumulation was observed in 7 (87.5%) of the 8 rabbits infected with S. aureus in the vertebrae and thigh bone. Of the rabbits infected with the gram-negative vertebrae, 1 (12.5%) showed little accumulation of 111In-WBC. Of the 8 rabbits with gram-negative-infected femurs, 1 had high accumulation and another had low accumulation of 111In-WBC, while the rest did not show any uptake. Osteomyelitis was confirmed by histopathology in all the successfully infected rabbits used for imaging. Conclusion: In the majority of the gram-positive-infected rabbit vertebrae there was high accumulation of 111In-WBC. However, no accumulation of 111In-WBC was observed in most of the vertebrae infected with gram-negative organisms, which release antichemotactic factors that prevent adequate accumulation of WBC at the infected area.

On radionuclide somatostatin receptor imaging studies, the spleen shows high physiologic uptake. Reducing the intensity of the image settings helps to better assess the distribution of radiotracer in the spleen. In our routine studies, we incidentally recognized that 68Ga-DOTANOC PET provides higher-resolution splenic images than 111In-octreotide SPECT. Autoradiography and immunohistochemistry studies have shown that somatostatin receptors are located mainly in the red pulp of the spleen. The distribution of 68Ga-DOTANOC in the spleen appears to correlate with the distribution of red pulp. In this article, we present 68Ga-DOTANOC PET/CT spleen images of our patients.

We incidentally identified gallbladder activity on 18F sodium fluoride (NaF) positron emission tomography/computed tomography (PET/CT) bone images in five patients. Variable degree of bowel activity is usually seen on NaF PET/CT images, and its mechanism is unknown. Gallbladder activity in our cases may indicate that hepatobiliary excretion of the 18F NaF is the reason for bowel activity on NaF PET/CT images. However, excretion of radiotracer through bowel may also contribute to the bowel activity.

Respiratory disease is an increasingly significant contributor to morbidity and mortality in the Western world. Lung cancer and chronic bronchitis continue to be major clinical problems. As the population lives longer, there are many older patients with pulmonary disease. These elderly patients are increasingly likely to undergo both emergency and elective surgery, with the associated risks of pulmonary embolism and postoperative infection.

Renal scintigraphy provides a unique tool for the noninvasive evaluation of renal pathophysiology. This chapter familiarizes the reader with the most frequently used nuclear medicine procedures for the evaluation of the common pathologic conditions in genitourinary system. These include studies for renovascular hypertension, urinary tract obstruction, urinary tract infection, renal transplant complications, vesicoureteral reflux, and testicular torsion.

Despite continuous advancements in prevention and treatment methods, inflammation is still a common clinical problem. The delineation of the site and extent of inflammation is crucial for appropriate clinical management of infection and for monitoring the response to therapy.

Radionuclide imaging of endocrine diseases has been in clinical application for many years. Over the past six decades, an increasing number of radionuclides and radiolabeled compounds are available for imaging the endocrine organs/tissues functions. Radionuclide imaging provides functional as well as morphological information on multiple endocrine organs especially thyroid, parathyroid, and adrenal glands. Endocrine nuclear medicine includes not only diagnosis but also internal radionuclide therapy. Recently, radiolabeled peptides have also been used for diagnostic and for therapeutic purposes.

Several scintigraphic imaging procedures are being used to diagnose and follow up gastrointestinal and hepatobiliary conditions. These functional studies provide information that is complementary to those of the morphologic studies and may not be demonstrated by them. The following is a brief discussion of the most common procedures.

Cerebral blood flow and metabolism are generally interconnected. Alterations in brain function are associated with corresponding changes in perfusion. Radionuclide brain perfusion studies using lipophilic tracers are useful in the study of abnormalities of regional perfusion such as stroke and in the evaluation of changes related to neuronal activity like epilepsy and trauma. Their use in psychiatric conditions is promising. Several radiopharmaceuticals are used for imaging central nervous system. These include 99mTc-HMPAO (Fig. 9.1), PET tracers such as F-18 FDG (Fig. 9.2) and less commonly In-111 DTPA.

Nuclear medicine provides important information for the diagnosis and management of several cardiovascular disorders. It provides noninvasive means for the evaluation of cardiac function. Myocardial perfusion imaging (MPI) is a commonly performed nuclear medicine study to determine the adequacy of blood flow to the myocardium, especially in conjunction with exercise or pharmacological stress for the detection and evaluation of coronary artery disease (CAD). Myocardial perfusion studies can be obtained using different radioisotopes and protocols. The one isotope protocol is commonly performed with Tc-99m compounds. The dual isotope protocol is performed using Tc-99m compounds along with thalium-201. More recently, positron-emitting radiotracers are used with added value in the evaluation and quantification of coronary artery disease as well as in the evaluation of myocardial metabolism and viability. Nuclear medicine also helps in the diagnosis of hemangioma and lymphedema.

Nuclear medicine has an important role in the management of benign and malignant bone diseases. This role has been expanding significantly particularly in the diagnosis of many benign diseases which may not be detected by morphologic modalities. Table 7.1 summarizes the modalities used in the diagnosis of bone diseases and their main advantages.

Nuclear medicine is a relatively new and rapidly changing specialty. It is based on the utilization of radioactivity to diagnose and treat medical conditions. Diagnostically, this imaging field provides assessment of the physiological functions of organs.

The use of F-18 sodium fluoride (NaF) positron emission tomography/computed tomography (PET/CT) bone scan is increasing because of its higher sensitivity and specificity over standard bone scintigraphy (BS). Studies previously reported a prostate-specific antigen (PSA) cutoff value for ordering standard BS. However, this has not been determined for NaF PET yet. In this study, our goal was to determine a PSA cutoff level for ordering NaF PET/CT bone scan. Newly diagnosed and previously treated prostate cancer patients who had NaF PET/CT scan and PSA measurements within 2 mos of PET study were selected for analysis. When available, other parameters, such as Gleason score (GS), clinical stage, alkaline phosphatase levels, skeletal symptoms, and correlative image findings, were recorded. Receiver operating characteristic (ROC) analysis was performed to determine PSA cutoff values. Sixty-two patients (32 newly diagnosed and 30 previously treated) met the inclusion criteria. Near half of previously treated patients were on hormone therapy. NaF PET/CT was positive in 9 newly diagnosed (PSA mean: 91.6 ng/ml, range: 6.2–226 ng/ml) and in 6 previously treated patients (PSA mean: 146.4 ng/ml, range: 6.6–675 ng/ml). ROC analysis indicated that PSA cutoff value for NaF PET/CT positivity was >20 ng/ml in newly diagnosed and >6 ng/ml in previously treated patients. PSA cutoff value for ordering NaF PET/CT in newly diagnosed patients does not seem significantly different than the previous results for BS (>20 ng/ml). However, we found a lower PSA cutoff value of >6 ng/ml in previously treated patients.

Newcastle disease virus (NDV), the type member of the species Avian avulavirus 1 (formerly known as avian paramyxovirus serotype 1), causes a highly contagious and economically important disease in a myriad of avian species around the globe. While extensive vaccination programs have been implemented in ND-endemic countries, the disease is continuously spreading in commercial, backyard, and wild captive poultry. In order to investigate the evolution of the virus and assess the efficiency of the vaccine regimens that are currently being applied in commercial poultry, four wild-bird-origin NDV strains were characterized biologically, based on mean death time and intracerebral pathogenicity index, and genetically, based on the cleavage motif (112RRQKRF117) in the fusion (F) protein. Based on these features, all of the isolates were characterized as velogenic strains of NDV. Phylogenetic analysis based on the complete genome sequence revealed clustering of these isolates within class II, genotype VII. This class of NDV remains the predominant genotype in the Egyptian poultry industry, as well as in those of many Asian and African countries. To investigate the potential of these wild-bird-origin NDV isolates to cause infection in domesticated poultry and to assess the efficacy of currently available vaccines for protection of commercial poultry, an extensive animal challenge experiment was performed. Cumulative clinicopathological and immunological investigations of virus-challenged chickens indicate that these isolates can potentially be transmitted between chicken and cause systemic infections, and the currently applied vaccines are unable to prevent clinical disease and virus shedding. Taken together, the data represent a comprehensive evaluation of the ability of Egyptian wild-bird-origin NDV strains to cause infection in commercial poultry and highlights the need for a continuous and large-scale surveillance as well as revised vaccine approaches. These integrated and multifaceted strategies would be crucial in any efforts to control and eradicate the disease globally.

Sarikaya, Ali (Trakya author) F-18-FDG PET brain imaging is commonly used in the early detection and differential diagnosis of various subtypes of dementias.F- 18-FDG PET images are mainly evaluated visually, and semiquantitative analysis programs are also commonly used in many centers. However, visual and semiquantitative analysis carry certain limitations. Visual assessment is subjective and dependent on expertise. Commercially available semiquantitative analysis programs have certain limitations such as suboptimal selection of brain areas or erroneous uptake normalization procedures that may provide inaccurate results, and physicians reporting semiquantitative results should be aware of these. In this pictorial review article, we will discuss the current status of F-18-FDG PET brain imaging in patients with dementia and present figures and semiquantitative analysis results of various sub-types of dementias as well as certain artifacts seen on F-18-FDG PET brain imaging studies.

Fluorine-18-sodium fluoride (F-NaF) PET/CT is a relatively new and high-resolution bone imaging modality. Since the use of F-NaF PET/CT has been increasing, it is important to accurately assess the images and be aware of normal distribution and major artifacts. In this pictorial review article, we will describe the normal uptake patterns of F-NaF in the bone tissues, particularly in complex structures, as well as its physiologic soft tissue distribution and certain artifacts seen on F-NaF PET/CT images.

BACKGROUND Three-quarters of patients with major depressive disorder have late-onset depression. Late-onset depression is more often associated with cognitive impairment than earlyonset depression and evidences showed a relationship between vascular factors and late-life depression. OBJECTIVES To compare cognitive functions between late-onset (g60 years) and early-onset (

Although scintigraphy has a limited role in the diagnosis of rheumatic diseases, it can provide important complementary information, and familiarity with the scintigraphic patterns of different disease conditions of the joints and periarticular structures is important. Scintigraphy, however, could be more useful in evaluating the activity of the disease processes. The scintigraphic pattern of different arthropathies varies depending on the type and phase of the condition. Some conditions affect mainly small or large joints, while others affect both in either symmetrical or asymmetrical fashion. Primary osteoarthritis and rheumatoid arthritis show a classically symmetrical uptake. When large joints as the shoulders, hips, or knees are only involved, it indicates certain conditions such as osteoarthritis, ankylosing spondylitis, calcium pyrophosphate dihydrate (CPPD) crystal deposition disease, or joint infection. Other radionuclides used in the diagnosis and follow-up of these conditions include 111In- and 99mTc-labeled poly- and monoclonal antibodies such as Tc-99m-labeled human polyclonal immunoglobulin G, Tc-99m-anti-E-selectin-Fab, respectively, Tc-99m hexamethylpropylene amine oxime (Tc-99m HMPAO), Tc-99m SC, Tc-99m nanocolloid, F-18 sodium fluoride, and F-18 fluoro-2-deoxy-D-glucose (FDG). The use of SPECT and pinhole techniques should be remembered since they add diagnostic value to the scintigraphic methods. F-18 FDG positron emission tomography has a potential to quantitatively assess the degree of arthritis activity.

Bone marrow imaging has an important role in evaluating specific aspects of bone marrow anatomy, physiology, and pathology. This chapter provides a brief review of bone marrow structure and function essential to the understanding of basic principles of bone marrow radionuclide imaging and its clinical uses. Imaging bone marrow using indium-111 chloride, technetium-99m (Tc-99m)-labeled microcolloids, or Tc-99m-labeled monoclonal antigranulocytic and antimyelocytic antibodies is presented. Results of studies evaluating bone marrow scanning in several disease processes are summarized. Special attention is paid to the importance of bone marrow scintigraphy in inflammatory bone disease.

Benign and malignant primary bone tumors are rare, while metastatic disease is a common occurrence. The efficacy of the several currently available imaging modalities in the detection, staging, and follow-up of patients with skeletal neoplasia varies. Evaluation of bone tumors involves a multimodality approach. Standard radiographs play an important role in the diagnosis of both primary and metastatic tumors. Computed tomography (CT) scan and magnetic resonance imaging (MRI) are often complementary and are particularly useful in primary bone tumors. CT scan is especially useful in evaluating the cortex. MRI is superior in evaluating the extent of several primary tumors and detecting bone marrow lesions. The role of bone scintigraphy in preoperative evaluation of primary tumors is limited. Bone scintigraphy, on the other hand, is an excellent cost-effective screening modality in detecting metastatic disease in patients with skeletal as in the case of extraskeletal malignancies. In breast, lung, and head and neck tumors, bone scan is rarely positive for metastasis in patients with low stage disease. PET using F-18 sodium fluoride and FDG or combined is more sensitive in detecting metastases. Metaiodobenzylguanidine (MIBG) scintigraphy is valuable in children with neuroblastoma. Conentional bone scan and other radionuclide modalities are valuable in the long-term follow-up of several cancers and in estimating the prognosis. The therapeutic response of malignant bone disease can particularly be assessed using PET and alternatively Tl-201 and Tc-99m methoxyisobutylisonitrile (MIBI).

Nuclear medicine has a limited but important role in trauma and its complications. It is particularly useful and indicated in radiologically occult acute fractures including those in children who are the victims of physical abuse and in stress fractures. It is also used in the assessment of physeal closure and stimulation after trauma and to predict the outcome of leg length by semiquantitative analysis. Bone scintigraphy can also detect chronic ligament and acute and chronic meniscal lesions. Certain technical considerations, particularly related to meticulous positioning, the use of single-photon emission computed tomography (SPECT), and the use of magnification during acquisition, are important to maximize the diagnostic yield of scintigraphic modalities, particularly bone scan in traumatic disorders. SPECT/CT has become an important tool in the evaluation and management of a wider variety of orthopedic patients including many traumatic conditions.

Although the use of SPECT/CT, PET/CT, and PET/MR in different bone diseases was discussed in several chapters of this book, a separate chapter putting together the clinical uses and impacts of such important modalities in the diagnosis and follow-up of bone diseases is thought to be warranted given the importance of such modern imaging modalities.

Aim The sulfonamide group is widely used for bacterial diseases including kidney and urinary tract infections. The present study investigates the effect of a sulfa drug on kidney function and renography studies by using a radionuclide. Methods Renography studies were performed on New Zealand white rabbits. Each rabbit was injected with 48.1 MBq technetium-99m mercaptoacetyltriglycine (99mTc-MAG-3). Dynamic images were acquired using a gamma camera. Radioactivity time curves were generated from the regions of interest, time to peak activity (Tmax) and time from peak to 50% activity (T1/2). Each rabbit served as its own control. The sulfa drug was given to these rabbits for 7 days (i.v injection 130 mg/kg daily in two divided doses; i.e. the single dose is 65 mg/kg), then dynamic images were acquired. Results Treatment with sulfa shifted the experimental curves to the right of the control curves. This result showed that there was a delayed renal uptake of 99mTc-MAG-3 and its clearance. Calculated averages of Tmax were 2.2 ± 0.3 and 5.9 ± 0.5 min; while for T1/2 were 3.1 ± 0.3 and 8.4 ± 0.6 min for control and sulfa-treated rabbits, respectively (n = 20; P

Objective: The aim of this study is to investigate the effect of microbiological characteristics of causative organisms on the scintigraphic patterns of labeled-white blood cells (WBC) scan in cases of proven osteomyelitis. Materials and Methods: Retrospective analysis of 25 patients referred with suspected osteomyelitis and had both bone and labeled-WBC scans performed and complete records of the microbiological culture of the causative organism. The bone and labeled-WBC scans were retrieved and reviewed by two nuclear medicine physicians. Any definite focal accumulation of labeled WBCs within the bone was considered positive for osteomyelitis. Diagnosis of osteomyelitis in the discharge summary was considered the reference standard and was based on a combination of the clinical scenario, imaging, and laboratory findings including microbiology. Correlation of the pattern of labeled WBC and the type of microorganisms was done. Results: A total of 16 patients were included in this study, seven females and nine males. Of these, seven patients had Gram-positive whereas nine patients had Gram-negative organisms. The majority (85.7%) of Gram-positive organisms showed increased accumulation of labeled WBCs, whereas only one-third (33.3%) of patients with Gram-negative organisms had such finding. Conclusion: The pattern observed in this study shows that the false-negative results of labeled-WBC scans were mainly noted in patients with Gram-negative as opposed to Gram-positive infections. This confirms the experimental animal study findings that the secretion of anti-chemotactic factors by Gram-negative organisms, seems to be inhibiting the migration of labeled WBCs to the site of infection. The inhabitation is decreasing the accumulation of labeled WBCs and consequently resulting in a false-negative finding. The study adds to evidence that microbiological characteristics of the causative organisms are another explanation for the false-negative WBC in proven osteomyelitis.

Thyroid scintigraphy plays an important role in the anatomical and functional evaluation of thyroid nodules which carry the risk of malignancy. The presence of multiple nodules carries overall smaller risk of cancer than solitary nodule. Missing nodules, whether solitary or multiple, may mean delaying detection of possible cancer. Therefore, it is important to improve the delectability of thyroid scintigraphy using most optimal imaging techniques. For pinhole thyroid imaging, there is a recent trend to omit oblique projections by some laboratories. The objective of this study was to reevaluate the impact of oblique projections in the detection of thyroid nodules. A total of 92 cases with nodular thyroid disease on routine pinhole thyroid scintigraphy was reviewed retrospectively. Two nuclear medicine physicians recorded the number of nodules based on the anterior view only and another time with adding the oblique views. A total of 192 nodules was detected using the three views. Sixty nodules (31%) were only seen on the oblique views and were missed on the anterior projections. Oblique pinhole projections are mandatory for adequate thyroid scintigraphy since 31% of nodules are missed if only anterior projection was used for interpretation. Following proper techniques will avoid missing of detection of nodule that may harbor cancer.

Background/Aim The Respiratory system can be affected by exposure to cold. It is well known that acute cold exposure induces asthmatic attacks. However, the influence of chronic cold environment exposure on lung perfusion and the pulmonary circulation was not studied in any previous study. Therefore this study was designed to investigates the effects of chronic cold exposure on lung perfusion using radionuclide study. Methods New Zealand White rabbits were used in these experiments. The rabbits were kept in the cold room (4 °C) for 7 weeks. Lung perfusion scintigraphy was performed at the end of this period. Each rabbit was injected with 74 MBq (2 mCi) technetium-99m macroaggregated of albumin ( 99m Tc MAA). Perfusion studies were done using Gamma camera equipped with a low energy, high resolution, parallel hole collimator interfaced with a computer. Static images were obtained 5 min after administration of the radiotracer. Static images were acquired include anterior/posterior (Ant/Post), right anterior oblique/left posterior oblique (RAO/LPO), right lateral/left lateral (RLat/LLat), right posterior oblique/left anterior oblique (RPO/LAO). Results Rabbits chronically exposed to cold had lesser lung perfusion than controls using radionuclide perfusion study. The lung counts of chronic cold exposure (4 °C) for 7 weeks on rabbit lung perfusion for 5 min was 64±4%. ( n =6, ⁎⁎⁎ P Conclusions Our results indicate that chronic cold exposure decreased pulmonary circulation and lung perfusion in normal subjects. Therefore chronic cold exposure might worsen some diseases that are affected by cold such as asthma.

Renal function and disease are commonly evaluated by radionuclide studies. The choice of radiopharmaceutical agent for various studies is crucial for proper interpretation. (99m)Tc-mercaptoacetyltriglycine ((99m)Tc-MAG3) is excreted almost exclusively by the renal tubules, whereas (99m)Tc-diethylenetriamine pentaacetic acid ((99m)Tc-DTPA) is predominantly excreted by glomerular filtration. The present study compared the effect of the nonsteroidal antiinflammatory drug (NSAID) diclofenac, which is the most commonly used drug to relieve kidney pain, on the kinetic behavior of administered (99m)Tc-MAG3 and (99m)Tc-DTPA in experimental animals.Two groups of 12 New Zealand White rabbits ((99m)Tc-MAG3 and (99m)Tc-DTPA) were used for the renography. Each rabbit served as its own control. The animals were given 60 mL of saline intravenously 30 min before each renographic study. A baseline study (control) was done by injecting 48 MBq (1.3 mCi) of (99m)Tc-MAG3, and renography was performed. Two days later, a single intravenous dose of diclofenac (2 mg/kg) (treated animals) was given, and after 20 min, (99m)Tc-MAG3 renography was performed. This procedure was repeated for the (99m)Tc-DTPA group after administration of 96 MBq (2.6 mCi) of the tracer. Dynamic images (as 2-s frames for the first minute and 30-s frames for the next 30 min on a 64 × 64 matrix) were acquired using a γ-camera equipped with a low-energy high-resolution collimator interfaced with a computer. Regions of interest were drawn over the whole kidneys. Time-activity curves were generated from the region of interest. Time to peak activity (T(max)), time from peak to 50% activity (T(1/2)), and the uptake slope of each kidney were calculated from the renograms for control and treated rabbits.Administration of diclofenac shifted the experimental renogram curves to the right, compared with the control curves, indicating that there was a delayed renal uptake of the 2 tracers and clearance of the radioactivity. The calculated average values of T(max) for control and treated rabbits using (99m)Tc-MAG3 were 1.8 ± 0.5 and 6.35 ± 0.4 min, respectively, whereas those of (99m)Tc-DTPA were 3.4 ± 0.4 and 18.2 ± 2 min, respectively. The T1/2 for control and treated rabbits for (99m)Tc-MAG3 were 3.2 ± 0.07 and 6.6 ± 0.07 min, respectively, whereas those for (99m)Tc-DTPA were 10.1 ± 1 and 35 ± 4 min, respectively. The differences were statistically significant (P0.05).This study showed that diclofenac delayed both T(max) and T1/2. The NSAID-induced kinetic changes were considerably greater for (99m)Tc-DTPA than for (99m)Tc-MAG3. On the basis of these findings, it is suggested that (99m)Tc-MAG3 be used to perform renography for studies involving the use of NSAID administration to decrease any change that may occur due to the type of tracer and not to the condition of the kidney.

Metabolic bone disease due to hyperparathyroidism is characterized by increased bone resorption and new bone formation. (99m)Tc- hexakis-2-methoxyisobutylisonitrile ((99m)Tc MIBI) accumulation is controlled by metabolic function and cell viability. To investigate, for the first time, the potential of whole body (99m)Tc MIBI scan for detecting, visually and with the aid of quantitative analysis, bony changes associated with hyperparathyroidism. Eighty-six patients with hyperparathyroidism, referred routinely for parathyroid localization, were included in this case-control prospective study. Each patient was injected with 20-25 mCi of (99m)Tc MIBI. Routine anterior cervico-thoracic images were obtained for parathyroid localization. Two extra whole body images were acquired and assessed visually and by drawing regions of interest over the mandible, sternum, femur, humeri, spine, and the soft tissue adjacent to the bone. The ratios of bone to soft tissue were calculated and compared to ratios drawn in a control group routinely referred for cardiac imaging and injected with (99m)Tc MIBI, after confirming the absence of any bone disease. The visual interpretation of the scans showed 48 patients to have increased bone uptake. Quantitative assessment showed significant difference between the mean ratios of the case and control groups. The Kruskal-Wallis test showed significant agreement between visual and quantitative ratios drawn from delayed right and left femora and left humerus images (P < 0.05). (99m)Tc MIBI whole body imaging is a potentially useful technique for assessing metabolic bone disease associated with hyperparathyroidism. Quantitative analysis helped in confirming the visual findings.

The practice of nuclear medicine in Kuwait began in 1965 as a clinic for treating thyroid diseases. The practice developed gradually and until 1981 when the Faculty of Medicine established the Division of Nuclear Medicine in the Department of Radiology, which later became a separate department responsible for establishing and managing the practice in all hospitals of Kuwait. In 1987, a nuclear medicine residency program was begun and it is administered by Kuwait Institute for Medical Specializations originally as a 4-year but currently as a 5-year program. Currently there are 11 departments in the ministry of health hospitals staffed by 49 qualified attending physicians, mostly the diplomats of the Kuwait Institute for Medical Specializations nuclear medicine residency program, 4 academic physicians, 2 radiopharmacists, 2 physicists, and 130 technologists. These departments are equipped with 33 dual-head gamma cameras, 10 SPET/CT, 5 PET/CT, 2 cyclotrons, 1 breast-specific gamma imaging, 1 positron-emitting mammography, 10 thyroid uptake units, 8 technegas machines, 7 PET infusion systems, and 8 treadmills. Activities of nuclear medicine in Kuwait include education and training, clinical service, and research. Education includes nuclear medicine technology program in the Faculty of Allied Health Sciences, the 5-year residency program, medical school teaching distributed among different modules of the integrated curriculum with 14 didactic lecture, and other teaching sessions in nuclear medicine MSc program, which run concurrently with the first part of the residency program. The team of Nuclear Medicine in Kuwait has been active in research and has published more than 300 paper, 11 review articles, 12 book chapters, and 17 books in addition to 36 grants and 2 patents. A PhD program approved by Kuwait University Council would begin in 2016.

Post-poliomyelitis syndrome causes variable musculoskeletal manifestations including pain, muscle weakness and fatigue. These manifestations are commonly secondary to overuse and misuse of muscles and joints and could follow a fall. Bone scan can be useful in determining the underlying cause and follow-up. The objective of this study was to describe the late scintigraphic patterns on bone scan following poliomyelitis.Bone scans of 8 adult patients (7 female and 1 male), aged 35 to 53 years, who were known to have paralytic poliomyelitis, were retrospectively studied. Six patients had unilateral while 1 had bilateral disease. All patients had three-phase bone scan and 5 had SPECT study as well. Studies were reviewed by two qualified nuclear medicine physicians and findings were recorded and analyzed.Several patterns were consistently identified: decreased blood pool activity in the affected lower limb of all patients; deformed ipsilateral hemi-pelvis with reduced uptake on the affected side in all patients with unilateral disease; stress changes with increased uptake in the bones of the contra-lateral lower extremity; and degenerative changes in multiple joints (shoulder, knee, hip, ankle and spine). Significant scoliosis was only noted in the patient with bilateral disease.Scintigraphic patterns on bone scan associated with the post-poliomyelitis syndrome and persistent weakness following a distant episode of poliomyelitis have been described. Awareness of these characteristic scintigraphic findings may facilitate an accurate diagnosis and lead to more appropriate patient management.

Background Heatstroke is a serious condition and clinical studies indicate that vascular stroke increases with excessive consumption of alcohol (ethanol). It was our objective to test the influence of ethanol on cerebral perfusion at normal and higher temperatures. Methods Recording of isometric tension in rabbit carotid artery strips in organ baths with different concentrations of ethanol at 37 degrees C and during hyperthermia (39-43 degrees C) and scintigraphic cerebral imaging of a radioactive isotope in the control situation and during hyperthermia. Results Stepwise heating induced reproducible reversible graded contraction, proportional to temperature. At high concentrations (toxic levels), ethanol induced an increase in tension and heating potentiated these responses. Extracellular Mg(2+) potentiated both heat-induced contraction and ethanol-induced contraction while extracellular Ca(2+) had no effect on these responses. During hyperthermia and ethanol scintigraphic isotope uptake was reduced in cortical and cerebellar regions. Conclusions Carotid artery vasomotor tone is temperature dependent and heating induces vasoconstriction. Alcohol (ethanol) at 37 degrees C elicited carotid artery contraction at high concentrations (toxic levels) but at any concentration during elevated temperature (39-43 degrees C). Ethanol potentiated the effect of hyperthermia-induced vasoconstriction and reduced cerebral perfusion as shown by radionuclide imaging. The synergistic effect of ethanol and hyperthermia may induce heat stroke and brain damage.

Background/Aim: Fever can be caused by different reasons such as environmental conditions, acute rejection after kidney transplantation and bacterial diseases including kidney and urinary tract infections. The present study represents a novel idea of investigating the direct effect of body temperature elevation on kidney function to determine whether hyperthermia alters the kidney function transiently leading to inaccurate findings and possible misinterpretation of the radionuclide (99mTc-MAG-3) renography studies. Methods: Renography studies were performed on New Zealand White rabbits weighing approximately 3–3.5 kg. Each rabbit was inject with 48.1 MBq (1.3 mCi) technetium-99m-mercaptoacetyltriglycine (99mTc-MAG-3). Studies were acquired using a gamma camera equipped with a low-energy, high-resolution collimator interfaced with a computer. Dynamic images were acquired as 2-s frames for the first 1 min and every 30 s for the next 30 min on a matrix of 64 × 64. Regions of interest were drawn over the whole kidneys. Radioactivity time curves were generated from the regions of interest. Time to peak activity (Tmax), time from peak to 50% activity (T½), and the uptake slope of each kidney were calculated from the renograms. Three days later the same protocol was repeated for the same rabbit but with a higher body temperature by 2°C. Then it was repeated with a higher body temperature by 3°C, then 4°C with the same interval period. Blood pressure was measured using a catheter inserted into the femoral artery connected to a Lectromid recorder at normal temperature and during increasing the temperature by 2, 3 and 4°C. Renal blood flow was also measured via the renal artery using an electromagnetic blood flow sensor connected to a flowmeter. Creatinine and blood urea nitrogen (BUN) in blood were measured in control and hyperthermic rabbits. Results: During hyperthermia the experimental curves shifted to the right of the control curves indicating that there was a delayed renal uptake of 99mTc-MAG-3 and clearance of radioactivity. This delay was proportional to body temperature. Calculated averages were: Tmax 1.6 ± 0.1, 2.8 ± 0.3, 8.8 ± 1, 15 ± 4 min; T½ 2.77 ± 0.2, 3 ± 0.4, 8.9 ± 1.1, 20 ± 3.4 min, and perfusion index 190 ± 5, 201 ± 4, 218 ± 7, 224 ± 9 of control and hyperthermic (elevation of temperature 2, 3, and 4°C) rabbits, respectively (n = 6; p < 0.05). Mean arterial pressure and renal blood flow did not significantly change during hyperthermia. Creatinine and BUN were proportionally elevated to high temperature. Conclusions: Our results indicate that hyperthermia causes a transient alteration in the function of the kidney and scintigraphic pattern on radionuclide renography. Radionuclide renography studies may be performed at normothermic temperature since interpretation at higher body temperature could lead to misleading results, and temperature should be checked and recorded for single and follow-up radionuclide renography studies.

The Cell: Structure, Function, and Molecular Biology.- Pathophysiology and Mechanisms of Radiopharmaceutical Localization.- Basis of Positron Emission Tomography Imaging.-Inflammation.- Nuclear Hematology.- Musculoskeletal System.- Thyroid Gland.- Parathyroid Gland.- Adrenal Gland.- Renal Scintigraphy.- Oncology 1: Basic Principles of Tumor Pathology and Biology.- Oncology 2: Tumor Imaging: Scintigraphic and Pathophysiologic Correlation.- Respiratory System.- Cardiology 1: Myocardial Contractility and Assessment of Cardiac Function.- Cardiology 2: Basis of Myocardial Perfusion, Metabolism, Infarction, and Receptor Imaging in Coronary Artery Disease and Congestive Heart Failure.- Digestive system 1: Gastrointestinal Tract.- Digestive system 2: Liver and Biliary Tract.- Basis and Clinical Application of Functional Brain Imaging.-Pathophysiological Aspects of Antibody Imaging.- Lymphoscintigraphy.- Basis of other Diagnostic Nuclear Medicine Procedures. Basis of Therapeutic Nuclear Medicine.- Biological Effects of Ionizing Radiation.

Aim To compare the quantitative algorithms Emory Cardiac Toolbox (ECTb), quantitative gated SPECT (QGS), layer of maximum counts (LMC), and left ventricular global thickening fraction (LVGTF) using gated myocardial tomography in the calculation of the left ventricular ejection fraction using the regression without truth (RWT) technique. Materials and methods Seventy-four consecutive patients were included in the study (59 males). All patients underwent stress-rest myocardial perfusion SPECT using 99m Tc-tetrofosmin. Analysis of variance (ANOVA), the paired Student's t-test, the Pearson correlation coefficient and Bland-Altman were used for comparing the methods. The relative accuracy was performed by RWT. Results ANOVA revealed a significant difference among the methods in calculating the ejection fraction. RWT showed that ECTb and QGS outperformed the other two methods. The ECTb was slightly better than QGS, and LMC was slightly better than LVGTF. QGS and ECTb achieved good correlations in end diastolic volume, end systolic volume and ejection fraction measurements. One-way ANOVA demonstrated that QGS was the only software program affected by the category of the perfusion summed stress score (SSS), P= 0.038. The ejection fraction determined by the QGS, ECTb and LVGTF methods correlated significantly with defect size (r= 0.545, P

Aim To compare the currently available gated SPECT software programs, quantitative gated SPECT (QGS), Emory Cardiac Toolbox (ECTb), Left Ventricular Global Thickening Fraction (LVGTF), and the recently developed Layer of Maximum Count (LMC) method with equilibrium Gated Blood Pool (GBP) scintigraphy in calculating the ejection fraction in patients with small hearts. Methods Twenty patients with small hearts (end diastolic volume

The digestive system consists of the gastrointestinal tract, hepatobiliary system (Fig. 16.1), pancreas, and salivary glands. Nuclear medicine is concerned with the evaluation of normal and abnormal functions of the gastrointestinal tract and hepatobiliary system. To date, the role of nuclear medicine in pancreatic disorders is limited to evaluation of its tumors which is dealt with elsewhere in the book. This chapter will deal with gastrointestinal tract and salivary glands, while the next chapter is devoted to the hepatobiliary system.

Several biological effects can result from ionizing radiation. These can be due to direct or indirect mechanisms, and they can be acute or delayed. Acute effects occur with exposure to high-level radiation. Delayed effects may appear after a long time and include cancer, genetic effects, effects on the unborn child, and other effects such as cataracts and hypothyroidism. Based on our current knowledge, no level of exposure to radiation can be described as absolutely safe and no level is uniformly dangerous. Radiation doses have to reach a certain level to produce acute injury but not to cause cancer or genetic damage. No biological effects in individuals have ever been documented as being due to levels of ionizing radiation employed for medical diagnosis. Absorbed doses from nuclear medicine procedures are very low. Fear of radiation must not be permitted to undermine the great value of radiation in clinical practice. However, safe handling of all levels of radiation is important to prevent or minimize possible biological effects.

Therapeutic applications of nuclear medicine are expanding (Table 20.1). Until few years ago, the use of radioisotopes in therapy was limited predominantly to treatment of hyperthyroidism, thyroid cancer, and polycythemia rubra vera. Strontium-89 (Sr-89), rhenium-186 (Re-186), samarium-153 (Sm-153), and tin-117m (Sn-117) have been increasingly used more recently in treating bone pain secondary to metastases. Additionally, treatment of certain neuroendocrine tumors with I-131 MIBG and labeled octreotide and pentreotide, the use of radiolabeled monoclonal antibodies for lymphomas, radionuclide treatment of primary and secondary liver lesions, and radionuclide synovectomy have revolutionized the field of therapeutic nuclear medicine.

Objective: To assess the efficacy and toxicity of rhenium-186 HEDP in treating metastases. Patients: Twenty-six patients with bone pain from metastatic cancer were treated with 35 mCi of 186Re HEDP administered intravenously in the outpatient clinic. Methods: Patients were followed with pain diaries, records of medication, morbidity, sleep patterns, serial bone scans and a Karnofsky index. Twenty-five patients with complete records were evaluated. Patients were grouped according to the extent of bone metastases as seen in the bone scans. Results: Sixteen patients (64%) showed clinical responses of which 4 became completely pain-free. Pain relief typically began 10–20 days after 186Re HEDP was administered, while maximum benefit was normally achieved by 6 weeks. Relief of pain was maintained for 4–15 months (mean 6 months). No immediate adverse reactions were observed following the administration of 186Re HEDP. Only a mild transient fall in platelet levels was noted, which normalized by 6 weeks. Conclusion: 186RE HEDP appears as a safe, convenient and an effective palliative for pain secondary to bone metastases in cancer patients.