[Pericardial liquid layer as an occasional finding in internal echography. Normal patterns and pathologic limits]. / Falda liquida pericardica come riscontro occasionale nell'ecografia internistica. Quadri normali e limiti con il patologico.

A small amount of fluid in the pericardial sac is often observed incidentally during upper abdomen US studies. In order to assess the normality range for this finding, 500 patients undergoing liver US were evaluated for the presence of pericardial fluid, the thickness of which was subsequently measured in positive cases. In a group of 20 patients with pericardial fluid thickness ranging 5-9 mm and in 6 cases with pericardial effusion greater than 10 mm, cardiologic evaluation was performed (clinical examination, ECG, echocardiography). Pericardial fluid was quite a common finding (20.8%) which had no clinical relevance when less than 10 mm. On the contrary, its clinical relevance was high when greater than 10 mm, and extending around the heart.

CT diagnosis of spontaneous dissection of the superior mesenteric artery.

We report two cases of spontaneous superior mesenteric artery dissection diagnosed by CT. In both cases lamination of the arterial wall and enhancement of both true and false lumina were the key to the diagnosis.

Gas-containing gallstones: their influence on ultrasound images.

The ultrasound image of gas-containing gallstones was evaluated in three cases. In two, the stones were studied in vitro in a phantom gallbladder by ultrasound, and then by microradiographic techniques. The third case was investigated in vivo by ultrasound and computerized tomography (CT). The presence of gas-containing fissures, which are not detectable on ultrasound, was demonstrated. In contrast, wider fissures, or a true gas bubble, produce reverberation echoes which depend upon the quantity of gas present within the gallstone.

[Liver metastases with posterior acoustic shadow in echography: causes and differential diagnosis]. / Metastasi epatiche con ombra acustica posteriore all'ecografia: cause e diagnosi differenziale.

Seven cases of metastases with acoustic shadow have been detected in a series of 108 liver metastases. In two cases this echographic pattern corresponded to calcified metastases and in one case to a necrotic metastasis, containing gas. In the last four cases the presence of an acoustic shadow (all colon carcinoma metastases in chemotherapy) must be attributed to the tissue characteristics of the lesion, since neither calcifications nor gas could be shown by CT. A possible effect of chemotherapy in causing this type of image can be thought to exist; this, according to the finding of hypoechogenic metastases turning to the same above mentioned pattern following chemotherapy.