Analysis of the utility of 2-[18F]FDG PET/CT in the diagnosis of vascular graft infection.

BACKGROUND: As a result of constantly improving surgical methods, an increasing number of patients have medical devices implanted in the cardiovascular system (including vascular grafts and endografts). Such patients are characterised by their high risk of infectious complications due to the possibility of biofilm formation on implanted material. This work aims to analyse the utility of 2-[18F]FDG PET/CT in diagnosing vascular graft and endograft infections. MATERIAL AND METHODS: The study was undertaken on a group of 58 patients, of whom 34 were in the study group, and 24 were in the control group. The 2-[18F]FDG PET/CT study was conducted in the Nuclear Medicine Department at the University Hospital of Lublin. The inclusion criteria for the study group were the presence of a vascular graft or endograft that encompasses the aorta, and strong clinical suspicion of its infection. The inclusion criteria for the control group were the presence of a vascular graft or endograft in the large arteries and the absence of signs of its infection on 2-[18F]FDG PET/CT, as well as the absence of clinically apparent signs and symptoms during six months of observation after 2-[18F]FDG PET/CT. All patients found in the database that met the criteria were included. RESULTS: Vascular endografts were more common in the control group than in the study group. However, in the case of infection of the vascular endograft, signs of infection in 2-[18F]FDG PET/CT were more severe. Images in the study group were divided into three groups that represent image patterns based on CT and PET characteristics. The first pattern (P1) was recognised in six patients. The second (P2) and third (P3) were visible in 11 and 17 patients, respectively. CONCLUSIONS: Comparative analysis of the study and control groups demonstrates the utility of 2-[18F]FDG PET/CT in the diagnosis of vascular graft/endograft infection.

68 Ga-Prostate-Specific Membrane Antigen PET/CT in Imaging of Hemangiopericytoma.

ABSTRACT: Hemangiopericytoma is a mesenchymal neoplasm that derives from pericytes surrounding the capillaries presenting overexpression of PSMA, which can be a source of pitfall in 68 Ga-PSMA-11 PET/CT. We reported 2 cases with recurrent hemangiopericytoma grade III with high expression of 68 Ga-PSMA-11 in PET/CT. Based on the performed examination, one of them received targeted α-therapy with the IV injection of 225 Ac-PSMA-617.

Detection of a second primary cancer in a 18F-fluorocholine PET/CT - multicentre retrospective analysis on a group of 1345 prostate cancer patients.

BACKGROUND: Aim of this study was to evaluate the rate of incidental detection of second primary cancer (SPC) at 18F-fluorocholine ([18F]FCH) positron emission tomography/computed tomography (PET/CT) performed in prostate cancer patients. MATERIAL AND METHODS: A retrospective analysis was performed on a group of 1345 prostate cancer patients, who underwent [18F]FCH PET/CT study because of suspicion of recurrence (n = 937) or for initial staging (n = 408). Images were acquired after intravenous injection [18F]FCH with a mean activity of 200 ± 75 MBq (5.4 ± 2 mCi), from the top of the head to the half of the thigh. The confirmation of second primary cancer was obtained from the cancer registry. RESULTS: Based on the [18F]FCH PET/CT scans, a second primary cancer was suspected in 89 patients (6.6%). Of these, a malignancy was histologically confirmed in 26 patients (29% of all suspected findings and 1.9% of the complete cohort). Lung cancer (including adenocarcinoma, neuroendocrine cancer) was diagnosed in 13 patients (50%) and hematologic neoplasm (including chronic lymphocytic leukemia, Hodgkin lymphoma, follicular lymphoma, and multiple myeloma) in 5 patients (19%). 18F-fluorocholine PET/CT also revealed esophageal cancer, mesothelioma, testicular, renal, bladder, and colorectal cancer inindividual patients, non-keratinizing squamous cell carcinoma (SCC) of the skin as well as head and neck SCC with unknown primary. CONCLUSION: We conclude that incidental detection of a second primary cancer in prostate cancer patients using [18F]FCH PET/CT is not very common and that lung cancer and hematologic malignancies are most frequently detected.

Normal ranges of renal function parameters for 99mTc-EC renal scintigraphy.

BACKGROUND: Dynamic renal scintigraphy remains the recognized method for evaluation of kidney function and perfusion. Although there is an extensive body of knowledge about the use of technetium-99m-mercaptoacetyltriglycine (99mTc-MAG3), much less has been written about renal technetium-99m-ethylenedicysteine (99mTc-EC) scintigraphy. The aim of this study was to determine the normal value of renal function parameters in 99mTc-EC dynamic renal scintigraphy: Tmax and T1/2. The effects of age, left or right side in the retroperitoneal space, and sex on those parameters were examined. MATERIAL AND METHODS: The research was conducted on 123 patients (F/M: 70/53; aged 2-71; averaging 14.8 years of age) with at least one normal kidney. A total of 194 healthy kidneys were examined, including pediatric kidneys. RESULTS: According to this study, the normal value of Tmax is 2.85 min (± 1.16) and T1/2 is 8.7 min (± 3.61). Values calculated for pediatric studies are Tmax is 2.81 (± 1.16) and T1/2 is 8.63 (± 3.71). CONCLUSIONS: The normal value of secretory and excretory renal function parameters was calculated. Although the value is slightly lower for children, this is not statistically significant, as globally there are no differences between the kidney-location sides and sexes for any parameter.

Patterns of vascular graft infection in 18F-FDG PET/CT.

BACKGROUND: 18F-FDG PET/CT has become an important tool in diagnosis of prosthetic vascular graft infections (PVGI). The aim of the study was to identify the patterns of vascular graft infection in 18F-FDG PET/CT. MATERIAL AND METHODS: The study was performed in 24 patients with vascular graft infection, in 17 patients implanted in an open surgery mode and in 7 patients by endovascular aortic repair (EVAR). Vascular prostheses were evaluated by two visual scales and semi-quantitative analysis with maximum standardized uptake values (SUV max). RESULTS: In the 3-point scale: 23 patients were in grade 1 and one patient was in grade 2. In the 5-point scale: 19 patients were in grade 5 with the highest activity in the focal area, 4 patients were in grade 4 and one patient in grade 3. The visual evaluation of 18F-FDG PET/CT study revealed that peri-graft high metabolic activity was associated with occurrence of morphological abnormalities (n = 21) like gas bubbles and peri-graft fluid retention or without abnormal CT findings (n = 3). The presence of the gas bubbles was linked to higher uptake of 18F-FDG (p < 0.01, SUVmax 11.81 ± 4.35 vs 7.36 ± 2.80, 15 vs 9 pts). In EVAR procedure, the highest metabolic activity was greater than in classical prosthesis (SUVmax 21.5 vs 13). CONCLUSIONS: 18F-FDG PET/CT is a very useful tool for assessment of vascular graft infections. CT findings like gas bubbles, or peri-graft fluid retention were associated with significantly higher glucose metabolism; however, in some cases without anatomic alterations, increased metabolic activity was the only sign of infection.

Nuclear cardiology: an overview of radioisotope techniques used in the diagnostic workup of cardiovascular disorders.

Cardiovascular diseases are the most common cause of death in patients over 60 years old. Pivotal imaging modalities in cardiac diagnostic workup are echocardiography, magnetic resonance, multi­row detector computed tomography, coronary angiography, and radioisotope tests. In this study, we summarize the techniques of nuclear medicine (positron emission tomography, single­photon emission computed tomography, radionuclide ventriculography) that could be implemented in the cardiovascular diagnostic algorithms. Despite being acknowledged in a few cardiology guidelines, these imaging methods are still underestimated by practitioners. Nevertheless, noninvasive diagnostic tools are of increasing potential and should be implemented whenever possible. We discuss the usefulness of particular techniques in the management of patients with obstructive and nonobstructive coronary artery disease, including assessment of myocardial perfusion, contractility, viability, and detection of unstable atherosclerotic plaques. Radioisotope imaging can also be valuable in the diagnostic workup of infective endocarditis, as well as cardiac sarcoidosis and amyloidosis. Apart from theoretical principles of nuclear cardiology, we also provide 3 case reports illustrating a practical implementation of these imaging modalities.

The importance of FDG PET/CT in the diagnostic process of the middle aortic syndrome in a 15-year-old boy patient with suspected systemic vasculitis and final diagnosis of Williams-Beuren syndrome.

The differential diagnosis in children with the systemic vasculopathy is still a challenge for clinicians. The progress in vascular imaging and the latest recommendations improve the diagnostic process, but only single reports describe the use of new imaging tests in children. The publication aims to demonstrate the important role of 18F-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography combined with anatomical computed tomography angiography (PET/CTA) imaging in the case of a 15-year-old boy with chest pain, intermittent claudication, hypertension and features of middle aortic syndrome in computed tomography angiography (CTA). The patient was suspected to have Takayasu arteritis, but was finally diagnosed with Williams-Beuren syndrome. The case indicates that the FDG PET/CT imaging might be essential in the diagnostic process of middle aortic syndrome in children. We suggest that this imaging technique should be considered in the diagnostic process of systemic vasculopathy particularly in children.

Replacement of infected aortoiliac vascular grafts with bifurcated BioIntegral Surgical No-React® bovine pericardial xenografts.

The infection of a vascular prosthesis is potentially fatal, and its effective treatment still remains the greatest challenge for vascular surgeons. We present our initial experience using bovine pericardial vascular prostheses to replace infected aortoiliac vascular grafts. Six consecutive patients with infection of the graft were prospectively included in this study. Infection of the vascular graft was confirmed by clinical symptoms, laboratory tests and the results of computed tomography and positron emission tomography/computed tomography. In all cases, the infected aortoiliac graft was surgically removed and replaced by the bovine-pericardial BioIntegral aortic-bifemoral prosthesis. Technical success was achieved in every case with no in-hospital or 30 days mortality. One patient required revision of distal anastomosis due to recurrent bleeding at day four after surgery. One patient presented with upper gastrointestinal tract bleeding during the postoperative period, which was managed endoscopically. The mean hospital stay was 14 days (range 9-19). The control CT scan performed 2 months after surgery showed significant regression of abscesses and periprosthetic inflammation. Two patients died within 32 months of follow-up: one due to heart attack, the other due to generalized sepsis, which was correlated with the previous infection. Four patients are still in follow-up. The BioIntegral prosthesis is patent in all four cases, with no clinical or ultrasonographic signs of infection. Our brief investigation shows that a bovine pericardial prosthesis may be a valuable option in the treatment of vascular grafts infections.

Subclinical hyperthyroidism in the course of autonomous nodules - clinical evaluation.

INTRODUCTION: Subclinical hyperthyroidism (SCH), also known as mildly symptomatic hyperthyroidism, has recently been diagnosed more frequently. One of the main endogenous causes of this disorder is autonomously functioning thyroid nodule (AFTN). Despite the fact that it is usually asymptomatic, SCH entails repercussions on the cardiovascular system and bone, and it carries a risk of progression to overt hyperthyroidism with a typical clinical picture. Treatment is still controversial, and its benefits are widely debated in literature. MATERIAL AND METHODS: From 459 patients authors selected a group of 49 patients (10.6% of all subjects with hyperthyroidism), 41 women (83.7%) with AFTN at the stage SCH treated in the Outpatient Endocrinological Clinic and the Department of Endocrinology of the Medical University of Lublin over a three-year period. The method applied in the study was a retrospective analysis of medical records with a particular account of medical history, physical examination, and additional tests obtained during the process of diagnostic and therapeutic procedures. RESULTS: Forty-one patients (83.7%) suffered from typical symptoms of hyperthyroidism; only eight patients (16.3%) were asymptomatic. The most frequently reported symptoms were tachycardia in women (51.2%) and anxiety in men (50%). The type of thyrostatic drugs and the length of therapy did not affect the outcome of iodine-131 therapy. In the vast majority of the patients (87.8%) radioidodine therapy was effective; 30 patients (61.2%) reached euthyreosis and 13 patients (22.5%) developed hypothyroidism. CONCLUSIONS: Most patients with SCH in the course of AFTN suffered from typical symptoms of overt hyperthyroidism; only every sixth patient was asymptomatic. The volume of autonomous adenomas did not affect the result of 131I therapy; however, the impact of AFTN volume as well as the thyroid volume on RIT efficacy requires futher investigation. In the vast majority of patients 131I therapy was an effective method of treatment, and an earlier therapeutic effect was observed more often in the patients with focal lesions located in the right lobe.

TeleNEN as a telemedicine model for neuroendocrine neoplasm management in case of Meckel's diverticulum NET.

A case of 25- years-old female with NET deriving from Meckel's diverticulum is described. The patient had one year history of dermatological skin problems. Ultrasound examination of abdomen performed because of arterial hypertension, revealed multiple hepatic lesions, which was confirmed in contrast enhanced CT. The typical contrast enhanced metastatic lesions in CT and elevated levels of chromogranin A suggested NET of unknown origin. SRS with 99mTc-HYNICTOC was perform for primary tumor localization, and revealed liver and paraaortic lymph nodes metastases, but no sign of primary tumor location. As a next step for primary tumor localization 68Ga-DOTATATE PET/CT was done, which revealed focus of increased uptake in small intestine considered to be the primary tumor site. The imaging and clinical history of patient was discussed on ENETS Tumor Board. Due to location of primary tumor in the small intestine with no anatomical changes in CT, laparotomy guided with gamma probe after 68Ga-DOTATATE injection was performed. During surgery procedure, the primary tumor was hardly palpable in the tip of Meckel's diverticulum, confirmed by gamma probe. After surgery, tandem peptide receptor radionuclide therapy (PRRT) was started. Patient received 4 doses of 90Y/177Lu-DOTATATE with total activity of 360 mCi (13.32 GBq). The three months follow up 68Ga-DOTATATE PET/CT had shown stable disease of patient. The presented case showed importance role of multidisciplinary team cooperation in patient management. Use of RGS is essential in cases like presented, when the tumor cannot be localized only by surgical palpation.

Therapeutic use of carbohydrate-restricted diets in an autistic child; a case report of clinical and 18FDG PET findings.

The ketogenic diet (KD) is a high-fat, adequate-protein, and low-carbohydrate diet that has been used successfully in the treatment of refractory epilepsies for almost 100 years. There has been accumulating evidence to show that the KD may provide a therapeutic benefit in autism spectrum disorders, albeit by a yet-unknown mechanism. We report a case of a 6-year-old patient with high-functioning autism and subclinical epileptic discharges who responded poorly to several behavioural and psychopharmacological treatments. The patient was subsequently placed on the KD due to significant glucose hypometabolism in the brain as revealed by an 18FDG PET. As soon as one month after starting the KD, the patient's behavior and intellect improved (in regard to hyperactivity, attention span, abnormal reactions to visual and auditory stimuli, usage of objects, adaptability to changes, communication skills, fear, anxiety, and emotional reactions); these improvements continued until the end of the observation period at 16 months on the KD. The 18FDG PET, measured at 12 months on the KD, revealed that 18F-FDG uptake decreased markedly and diffusely in the whole cerebral cortex with a relatively low reduction in basal ganglia in comparison to the pre-KD assessment. It warrants further investigation if the 18FDG PET imaging could serve as a biomarker in identifying individuals with autism who might benefit from the KD due to underlying abnormalities related to glucose hypometabolism.

Role of 18F-FDG PET/CT in the diagnosis of inflammatory and infectious vascular disease.

This review article discusses the utility of 18F-FDG PET/CT in diagnosis and management of vascular disease. We stress usefulness of this method in large vessel inflammation and infection. In our work we based on the literature analysis and clinical cases diagnosed in our institution by use of 18F-FDG PET/CT. The literature exploration was focusing on vascular inflammation and infections and 18-FDG PET. The search was performed on PubMed database and cross referencing. We present the practical review with several images of vascular diseases like: Takayasu arteritis, giant cell arteritis, vascular graft infections, abdominal aortic aneurysm infections and cases of aortitis and periaortitis. From this work inflammation associated with atheromatic process and vulnerable atherosclerotic plaque we excluded. 18F-FGD PET/CT is a sensitive metabolic, reliable, non-invasive imaging modality suitable for diagnosis and follow-up of inflammation and infections in vascular system.

Parathyroid cancer - difficult diagnosis - a case report.

Parathyroid cancer is a rare disorder of unclear etiology that is difficult to diagnose and treat. It is most often diagnosed incidentally based on multi-organ non-specific symptoms of hypercalcemia as a consequence of parathyroid hormone oversecretion. We present a case of a male with primary hyperparathyroidism who was diagnosed with parathyroid cancer ectopically located in the mediastinum only after the third surgery. However, due to chronic hypercalcemia, problems with localization and a bad clinical condition, the patient was not able to undergo a radical resection and one year after the first pathological fracture died. Taking into consideration the whole clinical picture we want to emphasize the need to apply comprehensive differential diagnosis of hypercalcemia and localization diagnosis of parathyroid tissue with a use of MIBI scintigraphy accompanied by the computed tomography and magnetic resonance imaging, as the most specific diagnostic tools employed in this pathology.

Multiple and solitary skeletal muscle metastases on 18F-FDG PET/CT imaging.

OBJECTIVE: The aim of this study was to investigate the features and patterns of skeletal muscle metastases (SMM) detected with F-fluorodeoxyglucose (F-FDG) PET/computed tomography (PET/CT). PARTICIPANTS AND METHODS: Our database was analyzed for patients with pathologically proven malignancy, who underwent F-FDG PET/CT in our institution. The patients with SMM were included in the study group on the basis of the final diagnosis confirmed by follow-up or histopathology. Images were acquired using a PET/CT system Biograph mCT S(64)-4R. CT was performed without contrast enhancement. RESULTS: The selected group included 31 patients (1.7% of the database, which consisted of 1805 patients). A total of 233 lesions were found. The prevalence of SMM evaluated in specific primary malignancies was the highest in melanoma (6.9%), followed by carcinoma of unknown primary (4.4%), colorectal cancer (4.1%) and lung cancer (2.8%). Three patterns of skeletal muscle metastatic involvement were observed: multiple SMM accompanied by other metastases (64.5%), solitary lesion associated with other metastases (29%) and isolated intramuscular lesions (two cases, 6.5%). Isolated SMM represented recurrence of the malignant disease. In patients with extraskeletal metastases, solitary or multiple SMM did not affect tumor staging. CONCLUSION: Solitary SMM are less common than multiple on F-FDG PET/CT imaging. SMM are usually associated with other metastases and do not affect tumor staging. The cases of isolated SMM are very rare. Nevertheless, in patients with a diagnosis of malignant disease, a solitary, F-FDG avid intramuscular focus should be suspected to represent metastasis.

Early brain perfusion improvement after ventriculoperitoneal shunt surgery in patients with idiopathic normal pressure hydrocephalus evaluated by 99mTc-HMPAO SPECT - preliminary report.

BACKGROUND: Idiopathic normal pressure hydrocephalus (iNPH) is a clinical syndrome that consists of the triad: gait disturbance, mental deterioration and urinary incontinence associated with normal cerebrospinal fluid pressure (CSF), without pre-existing abnormalities. The most popular treatment option is surgical implantation of a shunt. Brain perfusion increase occurring months or years after successful shunt surgery is well described in the literature. Early improvement of perfusion is not well documented. Therefore, the objective of the present study was to determine patterns of brain perfusion changes 3-6 days after the ventriculoperitoneal shunting in patients with iNPH by using 99mTc-HMPAO SPECT. MATERIAL AND METHODS: Sixteen patients with iNPH (9 women, 7 men, mean age 64.1 ± 12.7 years) who underwent ventriculoperitoneal shunt surgery were included into the study group. Indications for implanting a shunt were based on clinical history, neuroimaging and CSF dynamic studies with an infusion test. Brain perfusion SPECT was performed 1-2 days before and 3-6 days after the surgical treatment. For comparison of perfusion before and after the surgery SPECT scans were assessed visually and semiquantitatively with voxel based analysis. RESULTS: No side effects were observed after the surgery. Brain perfusion improvement after shunting was observed in 10 patients (62.5%). Patterns of perfusion changes varied between patients, with combinations of different bilateral and lateralized brain regions involved. Perfusion increased in the whole brain (3 patients), in the right cerebral hemisphere (1 patient) or in the separate cerebral regions (6 patients): frontal, parietal, temporal, cerebellum, cingulate gyrus. Perfusion improvement was predominantly observed in the frontal lobes: right frontal (3 cases, 18.8%), left frontal (3 cases, 18.8%). CONCLUSIONS: Cerebral perfusion is recovered promptly after ventriculoperitoneal shunt surgery in about 60% of patients with iNPH. This improvement may be global or regional in different cerebral areas with prevalence of the frontal lobes.

[Difficulty in diagnosis of primary hyperaldosteronism as the cause of resistant hypertension and severe hypokalemia--case report]. / Trudnosci diagnostyczne pierwotnego hiperaldosteronizmu, jako przyczyny opornego na leczenie nadcisnienia tetniczego i hipokaliemii--opis przypadku.

The most common endocrinological cause of secondary hypertension is primary hyperaldosteronism. Despite great progress in laboratory and imaging techniques, its identification is often difficult. We report the case of the 52-year-old man with resistant hypertension and severe hypokalemia. Renovascular hypertension, Cushing syndrome and pheochromocytoma were excluded as potential causes of drug-resistant hypertension in the presented case. Renal potassium excretion was significantly high. The results of plasma aldosterone concentration measured in supine position as well as in standing position were ambiguous. Computed tomography revealed abnormal round solid mass with a maximum diameter of 11 mm in the left adrenal. As there were not diagnostic results of laboratory research and ambiguous character of pathological structure in research computed tomography we have decided to carry adrenal cortex scintigraphy with iodomethyl-norcholesterol 131I. The result of this research was consistent with left adrenal scan of computed tomography and left adrenal adenoma has been confirmed. Normal blood pressure and normokalemia were restored after surgical treatment.

Cardiac sympathetic hyperactivity in chronic kidney disease--a comparison between haemodialysis and peritoneal dialysis patients.

BACKGROUND: The effect of renal replacement therapy on cardiac sympathetic function in patients with chronic kidney disease has not yet been completely elucidated. The aim of this study was to evaluate the impact of renal replacement therapy on the activity of cardiac sympathetic nervous system. MATERIAL AND METHODS: Thirty-four patients with chronic kidney disease were studied: 14 patients (6 men, mean age 48 ± 11 years) were receiving peritoneal dialysis (PD) and 20 patients (20 men, mean age 52 ± 10 years) were receiving haemodialysis (HD). Patients with diabetes and heart failure were excluded from the study. All patients underwent resting gated myocardial perfusion and ¹²³I-mIBG myocardial scintigraphy from which early and late heart to mediastinum ratios (HRM) and myocardial washout rate (WR) values were calculated. RESULTS: PD and HD patients did not differ with respect to left ventricular ejection fraction (52 ± 9% vs. 57 ± 7%) and summed rest score (3.8 ± 2.4 vs. 3.5 ± 0.3). Similarly, early (1.89 ± 0.23 vs. 1.87 ± 0.27) and late (1.76 ± 0.47 vs. 1.74 ± 0.25) HMR, and washout rate (35.5 ± 15.8% vs. 31.3 ± 9.4%) were not significantly different between the two groups of patients. CONCLUSIONS: These results suggest that the applied method of renal replacement therapy has no significant influence on global activity of cardiac sympathetic nervous system.