New insights on the active degassing system of the Lipari-Vulcano complex (South Italy) inferred from Local Earthquake Tomography.

Seismic tomography is a very powerful and effective approach to look at depths beneath volcanic systems thus helping to better understand their behaviour. The P-wave and S-wave velocity ratio, in particular, is a key parameter useful to discriminate the presence of gas, fluids and melts. We computed the first 3-D overall model of Vp, Vs and Vp/Vs for the Lipari-Vulcano complex, central sector of the Aeolian volcanic archipelago (southern Italy). The investigated area has been characterized in recent times by fumaroles, hydrothermal activity and active degassing. In particular, in the Vulcano Island, several episodes of anomalous increases of fumarole temperature and strong degassing have been recorded in the past decades and the last "crisis", started in September 2021, is still ongoing. For tomographic inversion we collected ~ 4400 crustal earthquakes that occurred in the last thirty years and we used the LOcal TOmography Software LOTOS. The results clearly depicted two low Vp and Vp/Vs anomalies located up to ~ 8 km depths below Vulcano and the western offshore of Lipari, respectively. These anomalies can be associated to the large presence of gas and they furnish a first picture of the gas-filled volumes feeding the main degassing activity of the area.

[Computerized tomography and magnetic resonance in the diagnosis of recurrent rectal neoplasms: comparison of reliability and errors of both methods]. / Tomografia computerizzata e Risonanza Magnetica nella diagnosi di recidiva delle neoplasie del retto: affidabilità ed errori delle due metodiche a confronto.

Our work was aimed at assessing the accuracy of CT and MRI in the early identification of postoperative recurrences of rectosigmoid cancer, quantifying false positive and false negative ratios and questionable findings. A homogeneous series of 50 patients submitted to surgery for primary rectosigmoid carcinoma was studied with both CT and MRI and followed-up for up to 2 years: local recurrences were observed in 15 patients (30%) which occurred within the first year of surgery in 67% of cases and were in extraluminal site in 86% of cases. CT appeared to be a reliable and highly sensitive screening method, with 82% sensitivity: only 2 false negatives were observed, which were nevertheless followed-up because CT had yielded questionable, and not negative, findings. In contrast, CT had only 78% specificity, being unable to differentiate fibrosis, displaced normal structures and recurrences in 7 cases; its positive predictive value (PPV) was 66%, with 89% negative predictive value (NPV) and 80% accuracy. MRI had a complementary role to CT, because of its capabilities in discriminating all the questionable CT cases and in identifying all CT false positives, thanks to its higher specificity (100%). MRI had 74% sensitivity, which was lower than that of CT; MRI yielded 2 false negatives which, however, had been previously diagnosed with CT. MRI had 100% PPV, 89% NPV and 92% accuracy. Therefore, for the early detection of rectal cancer recurrences, the following diagnostic protocol is suggested: CT should be performed first, as a screening method, within 2-4 months of surgery, and repeated every 6-8 months during the first 2 years-together with CEA values monitoring. MRI should be reserved to the patients in whom CT findings were positive, questionable, or in disagreement with clinical symptoms and/or with increasing CEA values. If MRI fails to solve the diagnostic doubt, a CT-guided biopsy of the mass should be performed.

[The role of the radiological hemithorax examination in closed trauma of the chest]. / Ruolo dell'esame radiologico dell'emicostato nei traumi chiusi del torace.

January, 1992, to September, 1994, a hundred and seventy-eight blunt chest trauma patients were examined with plain chest films and detailed rib studies. The patients were subdivided into three groups according to: a) the presence/absence of rib fractures correlated with clinical data; b) the depiction of rib fractures and/or thoracic complications; c) treatment customization in the presence/absence of rib fractures. In our series of patients the clinical data and the presence of rib fractures were poorly correlated. The detection rates of minor and major complications were also investigated on plain chest films and detailed rib studies. Plain chest films most frequently depicted the complications requiring conservative or surgical management and gave the indication for further imaging investigations. The detailed rib studies of the involved hemithorax yielded no further information useful to therapy except in few cases: and should therefore be limited to the cases exhibiting complications on chest films, which may benefit from surgical fixation. The accurate study of rib fractures is paramount in the cases where legal action may be undertaken.

[Imaging technics in the indications for laparoscopic cholecystectomy. Echotomography and cholangiography compared]. / Tecniche di imaging nell'indicazione alla colecistectomia laparoscopica. Ecotomografia e colangiografia a confronto.

March 1991 through October 1992, in the Clinica Chirurgica II of the Bologna University, 59 patients were submitted to laparoscopic cholecystectomy; the age range was 25 to 76 years and the mean 50 years. In no patient stones bigger than 35 mm were observed and 31% of the subjects were treated with litholysis before surgery. Fifty-eight patients were affected with single or multiple cholelithiasis, 1 had adenomyomatosis and 4 patients had associated choledocholithiasis treated with preoperative ERCP. Both US and cholangiography were performed to detect absolute contraindications--e.g., acute cholecystitis, cholangitis, peritonitis and cirrhosis--or relative contraindications--e.g., choledocholithiasis, > 5 mm stones and short cystic duct. US proved to be more sensitive than cholangiography to assess the number of stones and gallbladder wall thickness and to diagnose acute cholecystitis or scleroatrophic gallbladder, but it appeared to be less reliable in case of choledocholithiasis, where cholangiography was the technique of choice, and in possible anatomical variations--e.g., short cystic duct--which must be detected before laparoscopic cholecystectomy. Cholangiography appeared to be rather inadequate to study cholelithiasis when associated with functional gallbladder exclusion (as it happened in 17% of our patients). Intraoperative cholangiography was performed on 2 patients only, because their obesity hindered the preoperative study. In conclusion, the need is stressed of combining US and cholangiography for the accurate preoperative evaluation of gallbladder stones patients.