BackgroundVariation of the gene coding for D2 receptors (DRD2) has been associated with risk for schizophrenia and with working memory deficits. A functional intronic SNP (rs1076560) predicts relative expression of the two D2 receptors isoforms, D2S (mainly pre-synaptic) and D2L (mainly post-synaptic). However, the effect of functional genetic variation of DRD2 on striatal dopamine D2 signaling and on its correlation with prefrontal activity during working memory in humans is not known.MethodsThirty-seven healthy subjects were genotyped for rs1076560 (G>T) and underwent SPECT with [123I]IBZM (which binds primarily to post-synaptic D2 receptors) and with [123I]FP-CIT (which binds to pre-synaptic dopamine transporters, whose activity and density is also regulated by pre-synaptic D2 receptors), as well as BOLD fMRI during N-Back working memory.ResultsSubjects carrying the T allele (previously associated with reduced D2S expression) had striatal reductions of [123I]IBZM and of [123I]FP-CIT binding. DRD2 genotype also differentially predicted the correlation between striatal dopamine D2 signaling (as identified with factor analysis of the two radiotracers) and activity of the prefrontal cortex during working memory as measured with BOLD fMRI, which was positive in GG subjects and negative in GT.ConclusionsOur results demonstrate that this functional SNP within DRD2 predicts striatal binding of the two radiotracers to dopamine transporters and D2 receptors as well as the correlation between striatal D2 signaling with prefrontal cortex activity during performance of a working memory task. These data are consistent with the possibility that the balance of excitatory/inhibitory modulation of striatal neurons may also affect striatal outputs in relationship with prefrontal activity during working memory performance within the cortico-striatal-thalamic-cortical pathway.

BackgroundTo evaluate the common sources of diagnostic errors in emergency ultrasonography.MethodsThe authors performed a Medline search using PubMed (National Library of Medicine, Bethesda, Maryland) for original research and review publications examining the common sources of errors in diagnosis with specific reference to emergency ultrasonography. The search design utilized different association of the following terms : (1) emergency ultrasonography, (2) error, (3) malpractice and (4) medical negligence. This review was restricted to human studies and to English-language literature. Four authors reviewed all the titles and subsequent the abstract of 171 articles that appeared appropriate. Other articles were recognized by reviewing the reference lists of significant papers. Finally, the full text of 48 selected articles was reviewed.ResultsSeveral studies indicate that the etiology of error in emergency ultrasonography is multi-factorial. Common sources of error in emergency ultrasonography are: lack of attention to the clinical history and examination, lack of communication with the patient, lack of knowledge of the technical equipment, use of inappropriate probes, inadequate optimization of the images, failure of perception, lack of knowledge of the possible differential diagnoses, over-estimation of one’s own skill, failure to suggest further ultrasound examinations or other imaging techniques.ConclusionsTo reduce errors in interpretation of ultrasonographic findings, the sonographer needs to be aware of the limitations of ultrasonography in the emergency setting, and the similarities in the appearances of various physiological and pathological processes. Adequate clinical informations are essential. Diagnostic errors should be considered not as signs of failure, but as learning opportunities.

Aim The diagnosis, severity and extent of a sterile inflammation or a septic infection could be challenging since there is not one single test able to achieve an accurate diagnosis. The clinical use of 18F-fluorodeoxyglucose ([ 18 F]FDG) positron emission tomography/computed tomography (PET/CT) imaging in the assessment of inflammation and infection is increasing worldwide. The purpose of this paper is to achieve an Italian consensus document on [ 18 F]FDG PET/CT or PET/MRI in inflammatory and infectious diseases, such as osteomyelitis (OM), prosthetic joint infections (PJI), infective endocarditis (IE), prosthetic valve endocarditis (PVE), cardiac implantable electronic device infections (CIEDI), systemic and cardiac sarcoidosis (SS/CS), diabetic foot (DF), fungal infections (FI), tuberculosis (TBC), fever and inflammation of unknown origin (FUO/IUO), pediatric infections (PI), inflammatory bowel diseases (IBD), spine infections (SI), vascular graft infections (VGI), large vessel vasculitis (LVV), retroperitoneal fibrosis (RF) and COVID-19 infections. Methods In September 2020, the inflammatory and infectious diseases focus group (IIFG) of the Italian Association of Nuclear Medicine (AIMN) proposed to realize a procedural paper about the clinical applications of [ 18 F]FDG PET/CT or PET/MRI in inflammatory and infectious diseases. The project was carried out thanks to the collaboration of 13 Italian nuclear medicine centers, with a consolidate experience in this field. With the endorsement of AIMN, IIFG contacted each center, and the pediatric diseases focus group (PDFC). IIFG provided for each team involved, a draft with essential information regarding the execution of [ 18 F]FDG PET/CT or PET/MRI scan (i.e., indications, patient preparation, standard or specific acquisition modalities, interpretation criteria, reporting methods, pitfalls and artifacts), by limiting the literature research to the last 20 years. Moreover, some clinical cases were required from each center, to underline the teaching points. Time for the collection of each report was from October to December 2020. Results Overall, we summarized 291 scientific papers and guidelines published between 1998 and 2021. Papers were divided in several sub-topics and summarized in the following paragraphs: clinical indications, image interpretation criteria, future perspectivess and new trends (for each single disease), while patient preparation, image acquisition, possible pitfalls and

SPECT imaging is widely used for the differential diagnosis of degenerative parkinsonisms by exploiting the high affinitiy of the radiotracer (123)I-FP-CIT for the dopamine transporter. Reduced levels of DAT are found in Parkinson Disease (PD), Dementia with Lewy Bodies (DLB), and Progressive Supranuclear Palsy (PSP) compared to in Essential Tremor (ET) and Healthy Controls (HC). However, the extent of the neurodegenerative process may extend beyond nigrostriatal system. We have exploited the affinity of the same radiotracer (123)I-FP-CIT for the serotonin transporter to investigate SERT levels in the midbrain of patients with PD, DLB, PSP, and ET compared to HC. Using MRI images as anatomical templates for midbrain uptake quantification, we found a mild decrease in SERT levels in PD compared to ET and HC, with marked inter-individual variability; on the other side, PSP and DLB patients displayed markedly reduced to undetectable levels of SERT, respectively. These findings show that the neurodegenerative process affects serotoninergic neurons in parkinsonisms, with much more severe involvement in DLB than in PD patients, despite the comparable loss of striatal DAT. SERT-dependent (123)I-FP-CIT uptake may allow a more comprehensive assessment of neurochemical disturbances in degenerative parkinsonisms and may have a value for differential diagnosis.

Copper (Cu) is an important trace element in humans; it plays a role as a cofactor for numerous enzymes and other proteins crucial for respiration, iron transport, metabolism, cell growth, and hemostasis. Natural copper comprises two stable isotopes, 63Cu and 65Cu, and 5 principal radioisotopes for molecular imaging applications (60Cu, 61Cu, 62Cu, and 64Cu) and in vivo targeted radiation therapy (64Cu and 67Cu). The two potential ways to produce Cu radioisotopes concern the use of the cyclotron or the reactor. A noncopper target is used to produce noncarrier-added Cu thanks to a chemical separation from the target material using ion exchange chromatography achieving a high amount of radioactivity with the lowest possible amount of nonradioactive isotopes. In recent years, Cu isotopes have been linked to antibodies, proteins, peptides, and nanoparticles for preclinical and clinical research; pathological conditions that influence Cu metabolism such as Menkes syndrome, Wilson disease, inflammation, tumor growth, metastasis, angiogenesis, and drug resistance have been studied. We aim to discuss all Cu radioisotopes application focusing on 64Cu and in particular its form 64CuCl2 that seems to be the most promising for its half-life, radiation emissions, and stability with chelators, allowing several applications in oncological and nononcological fields.