Multicenter external validation of two malignancy risk prediction models in patients undergoing 18F-FDG-PET for solitary pulmonary nodule evaluation.

OBJECTIVES: To achieve multicentre external validation of the Herder and Bayesian Inference Malignancy Calculator (BIMC) models. METHODS: Two hundred and fifty-nine solitary pulmonary nodules (SPNs) collected from four major hospitals which underwent 18-FDG-PET characterization were included in this multicentre retrospective study. The Herder model was tested on all available lesions (group A). A subgroup of 180 SPNs (group B) was used to provide unbiased comparison between the Herder and BIMC models. Receiver operating characteristic (ROC) area under the curve (AUC) analysis was performed to assess diagnostic accuracy. Decision analysis was performed by adopting the risk threshold stated in British Thoracic Society (BTS) guidelines. RESULTS: Unbiased comparison performed In Group B showed a ROC AUC for the Herder model of 0.807 (95 % CI 0.742-0.862) and for the BIMC model of 0.822 (95 % CI 0.758-0.875). CONCLUSIONS: Both the Herder and the BIMC models were proven to accurately predict the risk of malignancy when tested on a large multicentre external case series. The BIMC model seems advantageous on the basis of a more favourable decision analysis. KEY POINTS: • The Herder model showed a ROC AUC of 0.807 on 180 SPNs. • The BIMC model showed a ROC AUC of 0.822 on 180 SPNs. • Decision analysis is more favourable to the BIMC model.

Assessing probability of malignancy in solid solitary pulmonary nodules with a new Bayesian calculator: improving diagnostic accuracy by means of expanded and updated features.

OBJECTIVES: A crucial point in the work-up of a solitary pulmonary nodule (SPN) is to accurately characterise the lesion on the basis of imaging and clinical data available. We introduce a new Bayesian calculator as a tool to assess and grade SPN risk of malignancy. METHODS: A set of 343 consecutive biopsy or interval proven SPNs was used to develop a calculator to predict SPN probability of malignancy. The model was validated on the study population in a "round-robin" fashion and compared with results obtained from current models described in literature. RESULTS: In our case series, receiver operating characteristic (ROC) analysis showed an area under the curve (AUC) of 0.893 for the proposed model and 0.795 for its best competitor, which was the Gurney calculator. Using observational thresholds of 5% and 10% our model returned fewer false-negative results, while showing constant superiority in avoiding false-positive results for each surgical threshold tested. The main downside of the proposed calculator was a slightly higher proportion of indeterminate SPNs. CONCLUSIONS: We believe the proposed model to be an important update of current Bayesian analysis of SPNs, and to allow for better discrimination between malignancies and benign entities on the basis of clinical and imaging data. KEY POINTS: • Bayesian analysis can help characterise solitary pulmonary nodules • Volume doubling time (VDT) is a good predictor of malignancy • A VDT of between 25 and 400 days is highly suggestive of malignancy • Nodule size, enhancement, morphology and VDT are the best predictors of malignancy.

Limited value of logistic regression analysis in solid solitary pulmonary nodules characterization: a single-center experience on 288 consecutive cases.

BACKGROUND AND OBJECTIVES: Preoperative characterization of the solitary pulmonary nodule is a delicate task faced by surgeons, radiologists, and clinicians. Mathematical models have been developed to overcome subjectivity. The Mayo Clinic model was suggested in the latest ACCP evidence-based clinical practice guidelines for the preoperative risk assessment of solitary pulmonary nodule malignancy. The aim of the study is to assess the validity of the Mayo Clinic model in a current continuous case series of biopsy-proven nodules. METHODS: The Mayo Clinic model was applied to estimate probability of malignancy in 288 consecutive cases in this single-center retrospective study. RESULTS: ROC curve analysis returned an AUC of 0.767, while analysis performed on 158 malignant nodules showed a mean predicted risk value of 38.15%. In our clinical setting, using a risk observational threshold set at 5% and a risk surgical threshold set at 60%, there would have been 4 cases of unnecessary surgery (false positives) at the cost of 13 cases of cancer progression (false negatives), while 68.75% of all nodules would have received non-decisional values. CONCLUSIONS: Surgeons should be aware that current data shows how the Mayo Clinic model is of little use in preoperative nodule characterization.

[Ultrasonography in acute diverticulitis of the colon: semiologic features]. / L'ecografia nella diverticolite acuta del colon: aspetti semeiologici.

To assess the ultrasonographic (US) patterns of acute colonic diverticulitis, we prospectively examined 21 patients. US was performed in all of them, CT in 13/21, contrast enema in 18/21 and endoscopy in 2/21 patients. US follow-up was carried out in 15/17 patients managed with conservative treatment. To analyze the US patterns of simple diverticula, we carried out an in vitro study of two surgical specimens with simple colonic diverticulosis. Wall thickening was seen in 21/21 cases, diverticula in 19/21, changes in pericolic fat in 11/21, local tenderness on gradual compression in 19/21 and changes in peristaltic activity in 21/21 cases. Even though diverticula may appear differently, we found 4 main patterns: round or linear hyperechoic pericolic outpouchings with no definite wall, usually with shadowing or reverberation artifacts (pattern 1), a saccular focus with a well-defined wall and various contents (pattern 2), a tubular structure with no content but with central linear echoes (pattern 3), and a flask-like or arrowhead-like hypoechoic focus (pattern 4). Patterns 1, 2 and 3 were shown in inflamed colic segments and in unaffected adjacent tracts, both in the acute phase and at follow-up, with no relevant morphological changes. In contrast, pattern 4 was observed in 10/19 patients, always in the acute phase and in affected colic tracts. The follow-up showed a decrease in size in 3 cases and a change to patterns 1, 2 or 3 in 7 patients. The authors believe pattern 4 to represent inflamed diverticula, while patterns 1, 2 and 3 indicate simple diverticula. Moreover the detection of diverticula and thickened wall segments does not necessarily indicate diverticulitis: thus, the diagnosis of this condition must rely on the presence of several signs, the most specific of which were, in our series, the flask-like and arrowhead-like patterns, presumptively expressing peridiverticular abscess.

[Do radiologists develop perceptual learning contrast sensitivity?]. / Esiste nei radiologi l'apprendimento percettivo nella sensibilità al contrasto?

A slight difference in brightness between objects close to each other and with no clear-cut outlines separating them can be recognized by the visual function called contrast sensitivity. This function is particularly developed in the radiologist, whose task is to analyze images in many shades of grey and with no clear-cut outlines, due to kinetic and radiogeometrical shading. Assuming that professional habit might develop this function, the authors compared contrast sensitivity in a group of 26 radiologists with contrast sensitivity in a control group (30 non-radiologists). The Vistech VTCS 6500 test was chosen for the task because of its practicality and reliability. The test consists in the recognition of the orientation of 5 series of alternate bright and dark lines differencing in thickness and contrast. The results obtained in the two groups were studied and compared with the statistical test of the analysis of variance, the T-test by Student and the U-test by Mann-Whitney. Contrast sensitivity was surprisingly higher in the radiologists group, in 4 of 5 series of images with bright and dark lines, than in controls and the difference was statistically significant: p < 0.001 with the test and the U-test. A deviation standard increase in contrast sensitivity was found also in radiologists with short-term professional activity (a few years). To explain these results, two hypotheses one suggested by the authors: radiologists pay greater attention to image details, because of their profession; perceptual learning--that is an improvement in the image-research cortical function--might occur, because of constant training. In the radiologist to conclude repeated stimulation of research capabilities in low-contrast images is thought to improve the efficiency of this cortical function.

[The echo-guided percutaneous therapy of dysontogenetic liver cysts]. / La terapia percutanea ecoguidata delle cisti epatiche disontogenetiche.

Congenital hepatic cysts are a frequent disease, symptomatic in 16-18% of the cases. The Authors report their personal experience about 4 cases and they make a review about 56 cases treated with ultrasonically-guided therapy. In 20 cases the therapy was simple aspiration, in 39 was alcohol sclerotherapy and in 1 was external percutaneous drainage. All the 20 cysts treated with simple aspiration recurred after 0.5-24 months. All the 39 patients treated with alcohol sclerotherapy presented a complete remission of symptoms and are disease-free after 1-48 months. The patient treated with percutaneous drainage, is disease-free after 10 months from the procedure. The alcohol sclerotherapy is the treatment of choice for the congenital hepatic cysts. The simple aspiration is an effective procedure only from a diagnostic point of view but not therapeutic. The external percutaneous drainage is the treatment of choice in case of infected cysts. Surgery is indicated only in the cysts with acute presentation, with biliary content and in case of failure of alcohol sclerotherapy.

[Radiological aspects of intestinal lipomas]. / Aspetti radiologici dei lipomi intestinali.

The radiological detection of intestinal lipomas is not unusual; however, in-depth studies of their radiological features have never been carried out, so far. Eighteen cases of intestinal lipoma were observed, out of different clinical histories. Through a careful survey of these cases, the authors describe the semiological characteristics of the lipomas, which were studied with radiographic contrast examinations of the small intestine and colon. In most cases the characteristics of the mass and--when present--the even more revealing features of its pedicle allowed the identification of such expansive lesions as lipomas. In some lesions detected by means of conventional methods CT proved extremely useful in diagnosing the nature of the lipomas. Such a diagnosis is extremely useful for it allows extensive surgery to be avoided and replaced with less extensive procedures--e.g. endoscopic removal of the lesion, or no specific treatment at all.

[Echographic monitoring of 80 renal transplants. Critical analysis of signs of graft rejection]. / Monitoraggio ecografico di 80 trapianti renali. Analisi critica dei segni di rigetto.

In a period of one year and a half, the follow-up of 80 patients after renal transplant has been monitored with echography. Altogether were made 418 echographies, which later were correlated with the clinical conditions of the patients at the moment of each echography. As rejection represents the most important complication, care was particularly given to the possibility of sonographic identification of such pathology. The sensitivity, specificity and diagnostic accuracy of each echographic sign in the diagnosis of rejection were evaluated. The absent or reduced renal sinus (sensitivity 63%) and hyperechogenicity of the cortical parenchyma (sensitivity 50%) resulted the most important signs in the diagnosis of rejection, while the increase of renal volume and the increased hypoechogenic pyramids resulted less reliable. The combination of three or more signs proved to be particularly significant.

[Importance of the dimensions and histologic nature of polyps of the colon in a comparison between double contrast enema and colonoscopy]. / Importanza delle dimensioni e della natura istologica dei polipi del colon nel confronto tra clisma opaco a doppio contrasto e colonscopia.

In 244 patients the results obtained by double contrast barium enema and endoscopy in the detection of small colonic polyps were compared. The results were evaluated by subdividing the polyps according to size. In order to define the endoscopic false positives percentage, controversial cases were re-examined with a second double contrast barium enema. The authors put forward a few considerations on the suitability of diagnosing small colonic polyps on the basis of their histologic nature.

[Ileal occlusion caused by the rupture and dislocation of a Celestin prosthesis. Radiological aspects. Presentation of 2 cases]. / Occlusione ileale da rottura e dislocazione di protesi di Celestin. Aspetti radiologici. Presentazione di 2 casi.

When the Celestin tube is used for treatment of benign oesophageal strictures after several months structural deterioration and fatigue occur. The tube disruption and displacement are serious complications which can be early identified with routine-radiological examinations.

[The syndrome of solitary rectal ulcer. Problems of radiologic diagnosis]. / La sindrome dell'ulcera solitaria del retto. Problemi di diagnosi radiologica.

The authors review 7 cases of syndrome of the solitary ulcer of the rectum, examined with barium enema. The radiological signs of this syndrome, rarely described in literature, are compared with those observed in this series.