The Role of the 18F-FDG PET/CT in the Management of Patients Suspected of Cardiac Implantable Electronic Devices' Infection.

Background: Infection of Cardiac Implantable Electronic Devices (CIEDI) is a real public health problem. The main aim of this study was to determine the diagnostic performance of 18F-FDG PET/CT in the diagnosis of CIEDI. Methods: A total of 48 patients, who performed 18F-FDG PET/CT for the clinical suspicion of CIEDI were retrospectively analyzed; all patients were provided with a model with procedural recommendations before the exam. Sensitivity (Se), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy (DA) of 18F-FDG PET/CT were calculated; the reproducibility of qualitative analysis was assessed with Cohen's κ test. The semi-quantitative parameters (SUVmax, SQR and TBR) were evaluated in CIEDI+ and CIEDI- patients using the Student' t-test; ROC curves were elaborated to detect cut-off values. The trend of image quality with regards to procedural recommendation adherence was evaluated. Results: Se, Sp, PPV, NPV and DA were respectively 96.2%, 81.8%, 86.2%, 94.7% and 89.6%. The reproducibility of qualitative analysis was excellent (K = 0.89). Semiquantitative parameters resulted statistically different in CIEDI+ and CIEDI- patients. Cut-off values were SUVmax = 2.625, SQR = 3.766 and TBR = 1.29. Trend curves showed increasing image quality due to adherence to procedural recommendations. Conclusions:18F-FDG-PET/CT is a valid tool in the management of patients suspected of CIEDI and adherence to procedural recommendations improves its image quality.

Lympho-SPECT/CT as a Key Tool in the Management of a Patient with Chylous Ascites.

Chylous ascites is a rare form of ascites usually associated with cirrhosis, abdominal malignancies, surgeries or infections. We presented a case of chylous ascites after robotic laparoscopic prostatectomy (PLDN-RALP), in which the correct diagnosis was achieved by SPECT/CT lymphoscintigraphy. A 72-year-old male developed chylous ascites after surgery and underwent lymphoscintigraphy with radiolabeled albumin nanocolloids for the supplementary study of the lymph flow and to detect a possible site of leakage. The scintigraphic imaging demonstrated the abdominal effusion and lymph stasis in the left iliac region. The combination of planar imaging with SPECT/CT can resolve the assessment of chylous disorders.

18F-Fluorocholine PET/CT, Tc-99m-MIBI and TC-99m-MDP SPECT/CT in Tertiary Hyperparathyroidism with Renal Osteodystrophy.

Tertiary hyperparathyroidism (HPT) is a metabolic disorder characterized by the semi-autonomous hypersecretion of parathyroid hormone (PTH), leading to hypercalcemia. It can be the end result of persistent secondary hyperparathyroidism and is most commonly observed in patients with long-standing chronic kidney disease (CKD) and often after renal transplantation. Untreated HPT can lead to progressive bone disease, fibrocystic osteitis, and soft-tissue calcifications, along with other severe complications. In the 2009 Kidney Disease Improving Global Outcomes (KDIGO) guidelines, CKD-Mineral and Bone Disorder (CKD-MBD) is used to describe the broader clinical syndrome encompassing mineral, bone, and calcific cardiovascular abnormalities that develop as a complication of CKD. We report a 62-year-old female with a severe HPT evolved from advanced chronic kidney disease (stage 5D, KDIGO). Patient was evaluated with multimodality nuclear medicine functional imaging to assess hyperfunctioning parathyroid glands and bone lesions. Tc-99m-methoxyisobutylisonitrile (MIBI) dual-phase scintigraphy, Tc-99m-methylenediphosphonate (MDP) bone scan and 18F-Fluorocholine positron emission tomography/computed tomography (18F-FCH PET/CT) were performed before surgery.

Usefulness of 18F-FDG PET/CT in Patients with Cardiac Implantable Electronic Device Suspected of Late Infection.

The presence of a cardiovascular implantable electronic device (CIED) can be burdened by complications such as late infections that are associated with significant morbidity and mortality and require immediate and effective treatment. The aim of this study was to evaluate the role of 18F-fluorodeoxyglucose positron-emission tomography/computed tomography (18F-FDG PET/CT) in patients with suspected CIED infection. Fifteen patients who performed a 18F-FDG PET/CT for suspicion of CIED infection were retrospectively analyzed; 15 patients, with CIED, that underwent 18F-FDG PET/CT for oncological reasons, were also evaluated. Visual qualitative analysis and semi-quantitative analysis were performed. All patients underwent standard clinical management regardless 18F-FDG PET/CT results. Sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) resulted as 90.91%, 75%, 86.67%, 90.91% and 75% respectively. Maximum standardized uptake values (SUVmax) and semi-quantitative ratio (SQR) were collected and showed differences statistically significant between CIED infected patients and those who were not. Exploratory cut-off values were derived from receiver operating characteristic (ROC) curves for SUVmax (2.56) and SQR (4.15). This study suggests the clinical usefulness of 18F-FDG PET/CT in patients with CIED infection due to its high sensitivity, repeatability and non-invasiveness. It can help the clinicians in decision making, especially in patients with doubtful clinical presentation. Future large-scale and multicentric studies should be conducted to establish precise protocols about 18F-FDG PET/CT performance.

The impact of lung perfusion scintigraphy in the emergency management of patients with suspected pulmonary embolism.

OBJECTIVE: Pulmonary Embolism (PE) is an emergency condition that requires immediate treatment. As the symptoms and the risk factors are nonspecific, PE differential diagnosis is often required. Even if angio-CT is considered the gold standard for PE diagnosis, the frequent allergic condition and/or chronic renal failure of patients make, in most cases, not possible the use of contrast enhancement in emergency with even more increasing use of Lung Perfusion Scintigraphy (LPS), as a simple and fast examination with no preparation/contraindication. The aim of our study is to highlight the role of LPS in the management of patients (pts) with suspected PE admitted to our hospital as an emergency in the "on-call" 24 hours (hrs) service. MATERIALS AND METHOD: We retrospectively revised 2166 LPS performed for suspected PE from January 2012 to December 2016, of which 1730 were urgent. LPS was performed according to the EANM guidelines in the 4 standard projections. The relation between symptoms, risk factors, dosage of D-dimers, other imaging diagnostic tools and LPS results were evaluated by contingency tables and Odds Ratio (OR). RESULTS: The origin unit of pts was: emergency (56.7%), pneumology (10.8%), neurology (4.8%), internal medicine (6.5%), surgery (5.2%), cardiology (3.3%) and other departments (11.2%). 59.3% of the examinations were performed during the on-call 24 hrs service. Symptoms were chest pain in 39%, dyspnea in 75%, cough in 22%. In 34% were present two symptoms, while 10% were asymptomatic. D-dimer dosage before LPS was increased in 97% (>500 ug/L). 55.5% had only one risk factor, 18.7% had two or more risk factors. 75.5% of pts had previously performed another diagnostic exam (Chest X-ray in 57%, chest CT in 8.4%, both in 10.1%) while 24.5% did not undergo previous diagnostic exam. The Chest X-ray and/or chest CT resulted negative in 25.4%, suspected for PE in 24.4%, non-specific with pleural effusion in 18.8% and non-specific with inflammatory interstitial diseases in 31.4%. LSP resulted positive for PE in 17% and then treated; LPS resulted negative in the remnant 83%. LPS results were associated with those of CT and Rx (χ2=17.5 P=0.001). LPS resulted positive in 13.8% with negative Chest X-ray and/or CT, in 23.4% with suspected PE, in 15.2% with pleural effusion and in 14.7% with inflammatory interstitial diseases. Furthermore LPS resulted positive in 17.32% without previous diagnostic exam. The increased value of D-Dimers (>500ng/ml) observed in 97% was not predictive of PE (OR=0.598 P=0.152). A similar result was observed for cough (OR=1.146 P=0.395) and chest pain (OR=0.927 P=0.601). Conversely, dyspnea appeared to be a significant symptom of PE (OR=1.596 P=0.003). The presence of risk factors is not predictor of PE detected by LPS (OR=1.297 P=0.089). CONCLUSION: LPS has a key role in the early diagnosis but even more in the exclusion of PE, optimizing the management of pts who do not require admission to intensive care unit with high costs and limited availability. LPS confirms to be a simple, quick and inexpensive examination. It does not require preparation and has no side effect so it can be performed in all types of pts including pregnant women, politraumatized and complicated patients, with great impact on resource optimization for intensive care units. Our multi-year and large-scale experience related to a metropolitan area suggests that, to date, given the great demand and relevance of this examination, Nuclear Medicine Units must necessarily be organized in order to provide LPS as emergency in on-call 24 hrs service.

Role of (18)F-FDG PET/CT in the evaluation of response to antibiotic therapy in patients affected by infectious spondylodiscitis.

OBJECTIVE: Spondylodiscitis is characterized by infection involving the intervertebral disc and adjacent vertebrae. It can occur anywhere in the vertebral column but more commonly involves lumbar spine. Our aim was to evaluate the usefulness of (18)F-FDG PET/CT to detect the early response to antibiotic therapy in patients affected by infectious spondylodiscitis and to compare the role of (18)F-FDG PET/CT and MRI in post-treatment evaluation. MATERIALS AND METHODS: 15 patients (12M, 3F), with mean age 65±13 years old, with typical clinical symptoms of Infectious Spondylodiscitis (pain, fever and increase of inflammatory indexes) and confirmed by blood culture or vertebral biopsy underwent within three day-interval a (18)F-FDG PET/CT and Magnetic Resonance (MR) at "baseline" and after antibiotic therapy. Semiquantitative parameters at (18)F-FDG PET/CT "baseline" SUVmax1, MTV1 and TLG1 and after therapy SUVmax2, MTV2 and TLG2 of involved vertebrae were calculated. Follow-up period of at least three months was available for all patients. T-student test for paired groups was performed to compare baseline and after therapy (18)F-FDG PET/CT semiquantitative parameters. RESULTS: According to (18)F-FDG PET/CT parameters all patients showed a response to antibiotic therapy. All patients were positive at "baseline" MRI of the spine, while at follow-up, 7/15 patients showed MR signs of infection and were considered "positive" and 8/15 showed resolution of infectious condition and, therefore they were considered "negative". A statistical significant difference between (18)F-FDG PET/CT "baseline" and after antibiotic therapy was found for all semiquantitative parameters: SUVmax (t=5.8, P=0.01); MTV (t=5.17, P=0.001); TLG (t=5,26, P=0,001). The comparison between the "baseline" and "after treatment" (18)F-FDG semiquantitative parameters showed a significant reduction of all parameters. This reduction was relevant also in patients with positive post-treatment MRI. This can be probably related to the tissue remodeling in the very immediate phase post-treatment, resulted positive at MRI and negative at (18)F-FDG PET/CT. Clinical follow-up of at least three months confirmed these results. CONCLUSIONS: (18)F-FDG PET/CT is useful to detect the early response to antibiotic therapy in patients affected by infectious spondylodiscitis. (18)F-FDG PET/CT semiquantitative parameters provide critical diagnostic information of the infectious process. (18)F-FDG PET/CT should be considered as first-line exam in the early post-treatment evaluation of spondylodiscitis while MR should be preferred for delayed assessment.

[Unusual sentinel lymph nodes detected by lymphoscintigraphy in cutaneous melanoma patients]. / Linfonodi sentinella "inusuali" alla linfoscintigrafia in pazienti con melanoma cutaneo.

Lymphoscintigraphy and radio-guided research of the sentinel lymph node is the most important investigation in the staging of patients with cutaneous melanoma, because it allows the identification of the lymphatic drainage pathways, not always predictable, and locate the sentinel node in classic basins and in "unexpected" regions. The aim of this study was to evaluate the incidence of cases of unusual sentinel nodes detected by lymphoscintigraphy and their prognostic significance in patients with cutaneous melanoma.

18F-FDGPET/CT: diabetes and hyperglycaemia.

BACKGROUND: Some patients who undergo 18F-FDG PET/CTfor neoplastic or benign disease are also affected by diabetes or hyperglycaemia. We propose different preparation procedures inpatients (pts) with hyperglycaemia (acute, temporary or chronic)or diabetes (type 1 or 2) at the time of the 18F-FDG injection, in order to improve the diagnostic scheduling of 18F-FDG PET/CT. MATERIAL AND METHODS: We evaluated a sample of 13,063 pts, examined in two different PET/CT centres, one with a stationary scanner (94.4%) and the other with a mobile device (5.6%). High blood sugar was present in 1,698 patients (13%) at the time of the 18F-FDG injection (hyperglycaemia was defined as fasting blood glucose > 11.1 mmol/l). We considered all 18F-FDG PET/CT tests performed over a period of 4 years (2006-2009). In the first 2 years (6,236 tests), scheduling was done directly by the administrative secretary. In the next two years, 6,827 pts underwent a preliminary visit to assess the test indications, medical history, and therapy as well as pre-test preparation. We evaluated different preparation protocols for hyperglycaemic or diabetic pts, especially those recommended in the guidelines of the European Association of Nuclear Medicine (EANM) and Society of Nuclear Medicine (SNM). RESULTS: In the four-year period, 713/13,063 patients (5.45%)were rescheduled; of these, 78.8% were rescheduled in the two years before the implementation of our preparation protocols and 21.2% in the next two years.Before the implementation of our preparation protocols, 562 patients (9%) presented occasional, acute or chronic hyperglycaemia (56.7%), or diabetes (43.3%), requiring postponement of the test to a later date. The test was not performed in 17 of 6,236 pts (0.27%) because of blood glucose levels above 11.1 mmol/l for several days, while in 16/6236 pts (0.26%) the18F-FDG injection was performed despite high blood glucose levels, in view of the clinical urgency.After the implementation of the preparation protocols, 2.2% of pts were rescheduled because of occasional, acute or chronic hyperglycaemia (79%), or diabetes (21%); 0.1% of pts did not undergo the test because of chronic high blood glucose levels. Although the administration of insulin is recommended in theEANM and SNM guidelines, in our new preparation procedures experience it was not necessary, because we reduced the numbers of hyperglycaemic pts thanks to screening at the preliminary visit and a subsequent good preparation of the patient before scheduling. CONCLUSIONS: The application of our preparation protocols improves the on-time performance and diagnostic accuracy,and increases patients' compliance.

[Striatal dopamine transporter levels in patients with REM sleep behavior disorder: assessment with 123I-FP-CIT SPECT]. / Livelli striatali del trasportatore della dopamina nei pazienti affetti da disturbo comportamentale del sonno REM: uno studio SPECT con 123I-FP-CIT.

REM sleep Behaviour Disorder (RBD) is a sleep disorder that can precedes the development of motor signs of Parkinson's disease by years. The aim of this study was to assess the functional integrity of nigrostriatal dopaminergic system in RBD patients using 123I-2b-carbomethoxy-3b-(4-iodophenyl)-N-(3-fluoropropyl) nortropane (123I-FP-CIT) Single-Photon Emission Computed Tomography (SPECT). 5 patients with RBD and 5 normal healthy controls were included in the study and underwent SPECT imaging 3 hours after injection of 111-185 MBq of 123I-FP-CIT. All RBD patients showed reduced 123I-FP-CIT striatal binding. 123I-FP-CIT SPECT is a useful diagnostic tool in RBD patients.

[Lymphoscintigrams with anatomical landmarks obtained with vector graphics]. / Linfoscintigrafie distrettuali e whole body associate a profilo anatomico modificabile, prodotte con tecnica vettoriale.

Nuclear medicine images are difficult to interpret because they do not include anatomical details. The aim of this study was to obtain lymphoscintigrams with anatomical landmarks that could be easily interpreted by General Physicians. Traditional lymphoscintigrams were processed with Adobe© Photoshop® CS6 and converted into vector images created by Illustrator®. The combination with a silhouette vector improved image interpretation, without resulting in longer radiation exposure or acquisition times.