The role of the deep convolutional neural network as an aid to interpreting brain [18F]DOPA PET/CT in the diagnosis of Parkinson's disease.

OBJECTIVES: To test the performance of a 3D convolutional neural network (CNN) in analysing brain [18F]DOPA PET/CT in order to identify patients with nigro-striatal neurodegeneration. We evaluated the robustness of the 3D CNN by testing it against a manual regional analysis of the striata by using a striatal-to-occipital ratio (SOR). METHODS: We analyzed patients who had undergone [18F]DOPA PET/CT from 2016 to 2018. Two examiners interpreted PET/CT images as positive or negative. Only patients with at least 2 years of follow-up and an ascertained neurological diagnosis were included. A 3D CNN was developed to evaluate [18F]DOPA PET/CT and refine the diagnosis of movement disorder. This system required training and testing, which were carried out on 2/3 and 1/3 of patients, respectively. A regional analysis was also conducted by drawing region of interest on T1-weighted 3D MRI scans, on which the [18F]DOPA PET images were first co-registered. RESULTS: Ninety-eight patients were enrolled: 43 presented nigro-striatal degeneration and 55 negative cases used as controls. After training on 69 patients, the diagnostic performance of the 3D CNN was then calculated in 29 patients. Sensitivity, specificity, negative predictive value, positive predictive value and accuracy were 100%, 89%, 100%, 85% and 93%, respectively. When we compared the 3D CNN results with the SOR analysis, we found that the two patients falsely classified as positive by the 3D CNN procedure showed SOR values ≤ 5th percentile of the negative cases' distribution. CONCLUSIONS: 3D CNNs are able to interpret [18F]DOPA PET/CT properly, revealing patients affected by Parkinson's disease. KEY POINTS: • [18F]DOPA PET/CT is a sensitive diagnostic tool to identify patients with nigro-striatal neurodegeneration. • A semiquantitative evaluation of the images allows a more confident interpretation of the PET findings. • 3D convolutional neural network allows an accurate interpretation of 18F-DOPA PET/CT images, revealing patients affected by Parkinson's disease.

A pilot study assessing tolerance safety and feasibility of diagnostic transnasal esophagogastroduodenoscopy using an improved larger caliber endoscope and an adapted topical anesthesia.

BACKGROUND: Transnasal esophagogastroduodenoscopy (TN-EGDS) is well tolerated by patients and the examination is perceived comfortable without the need of a sedative drug. Conversely, mainly in Western literature, some authors report limitations in illumination, image quality, and working channel as affecting TN-EGDS diffusion. To overcome these disadvantages, a new transnasal endoscope (TNE) was tested but, due to its larger diameter, we have no evidence of its clinical safety and tolerability. A new adapted nasal anesthesia could be useful to improve TNE tolerance. In an independent, not sponsored, pilot prospective study we enrolled, in a busy clinical hospital setting, 30 adult patients receiving nasal atomized Lidocaine and Xylometazoline (XAL) to undergo a diagnostic TN-EGDS with TNE to evaluate its tolerance, safety, and feasibility. METHODS: Three physicians enrolled inpatients and outpatients with indication to diagnostic EGDS during a 6-month period. Main outcome measures were cardio-pulmonary monitoring data and patients' answers to an adapted questionnaire investigating pain, anxiety level, willingness to repeat the examination, operators' scores about endoscopy quality, examination conduction and anesthesia-related complications. RESULTS: The examination was completed by the transnasal route in 100 % of the enrolled patients, endoscopy satisfaction and feasibility were scored to nearly the highest levels by the three different physicians. A total of 29/30 patients (96.6 %) declared the willingness to repeat the same examination if needed. The mean patients' score for overall pain was 3.7 ± 1 SD (range 1-10 by Visual Analog Scale). Mean endoscopy duration was 11.1 ± 2.6 min (range 5.0-19.0). In a total of 17/30 TN-EGDS that lasted more than 11 min, higher heart frequency variations and worse tolerance scores were found (p < 0.05). CONCLUSION: Our pilot study demonstrates that TN-EGDS with TNE and NA is safe, well tolerated, and feasible. The best clinical tolerance is reached when TN-EGDS lasts <11 min.

Intentional ingestion of elemental mercury requiring multi-step decontamination and prophylactic appendectomy: a case report and treatment proposal.

BACKGROUND: Ingestion of elemental mercury (Hg0) is considered non-toxic. After massive ingestion, local intestinal complications may develop: retention within appendix is quite frequent but treatment is debated. We describe a case of intentional ingestion of Hg0 requiring multi-step decontamination and prophylactic appendectomy. Case detail: A 19-year-old woman was admitted to ED for abdominal pain. History revealed ingestion of large amount of Hg0 as suicide attempt. To prevent absorption, facilitate elimination, and avoid complications a conservative approach was started. Due to inefficacy of initial maneuvers colonoscopy with irrigation/aspiration was performed, repeated whole bowel irrigation was continued and second colonoscopy was performed to clean residual metal. Abdominal plain films confirmed the presence of retained mercury within the appendix in asymptomatic patient. To reduce risk of appendicitis, potential perforation, and possibly systemic toxicity, a prophylactic laparoscopic appendectomy was performed at day 5 with removal of all retained mercury without peritoneal spillage. Highest mercury concentration was 22.7 mcg/L in serum (1-4.5 mcg/L) and 5.1 mcg/L in urine (0.1-5 mcg/L). CONCLUSIONS: After ingestion, metal retention in appendix is quite frequent. Evidence about optimal treatment are different and based on case reports. A multi-step approach with multidisciplinary evaluation tailored to the patient is suggested.