[The magnetic resonance of small hepatocarcinoma. A comparison with echography, computed tomography, digital angiography and computed tomography with lipiodol]. / La risonanza magnetica del piccolo epatocarcinoma. Confronti con ecografia tomografia computerizzata, angiografia digitale e tomografia computerizzata con Lipiodol.

Diagnostic techniques as a whole and periodic ultrasonography (US) in particular frequently allows tumors < 3 cm (small hepatocellular carcinomas) to be detected in patients suffering from liver cirrhosis. Multifocal diseases are a major limitation to surgery. Recently, MR imaging has shown its capabilities in the diagnosis of small hepatocellular carcinomas. In our study the diagnostic value of MR imaging was compared with that of US, of pre- and post-contrast CT, of digital angiography and of CT after lipiodol injection (Lipiodol CT). The morphologic and signal intensity MR features of small hepatocellular carcinomas were investigated. Fifteen cirrhotic patients with 31 nodules of hepatocellular carcinoma < 3 cm were examined. All patients were studied with US, MR imaging, angiography and Lipiodol CT; 12/15 patients underwent CT. Histologic confirmation was obtained in 12 nodules (2 at surgery and 10 by means of percutaneous biopsy); in the extant 19 cases the diagnosis was made by combining US, CT, MR, angiographic and lipiodol-CT findings; in 9 tumors < 1 cm Lipiodol retention one month after angiography was considered as diagnostic. MR imaging detected 21/31 nodules (63%), US 22/31 (66.6%), CT 12/24 (50%), angiography 24/31 (74%), lipiodol CT 29/31 (92.5%). Mc Nemar test showed no difference in sensitivity between MR imaging and CT, MR and angiography, MR and US, lipiodol CT and angiography; however, the differences between the detection rates of MR imaging and Lipiodol CT and CT and lipiodol CT and US were statistically significant (p < 0.05). The difference in sensitivity between the detection rates of lipiodol CT and US was just above the threshold value which is usually considered significant (p = 0.065). One false positive was observed on US and none with MR, CT, angiography and lipiodol CT. On Se T1-weighted images 18 nodules were hyperintense, 2 isointense and 2 hypointense; on proton-density images 14 nodules were hyperintense, 7 isointense and none hypointense. On SE T2-weighted images 18 nodules were hyperintense, 3 isointense and none hypointense. A pseudocapsule was seen in 10/17 nodules (58%), especially on T1-weighted images. Accuracy and limitations of each technique and morphologic and signal intensity MR findings of small hepatocellular carcinoma are discussed. We believe that US is still the best diagnostic technique for the screening of hepatocellular carcinomas in cirrhotic livers.(ABSTRACT TRUNCATED AT 400 WORDS)

MR of benign peripheral nerve sheath tumors.

Seventeen benign peripheral nerve sheath tumors were studied using MR. In all cases T2 relaxation time, signal intensity on T1-weighted images (lesion/muscle ratio), detectability of nerve of origin, nerve-lesion relationship, and presence of a capsule were assessed. Sixteen tumors showed marked hyperintensity on T2-weighted images with T2 relaxation times values greater than 95 ms. One schwannoma was almost isointense with fat (T2 60 ms). All lesions were isointense with muscle on T1-weighted images. In schwannomas the nerve was usually situated at the periphery of the lesion and only in one case was it obliterated by the mass. In neurofibromas the nerve was either visible in a central position within the mass (two cases) or no longer visible (five cases). A capsule could be detected in 70% of the schwannomas and in 30% of the neurofibromas. In patients with soft tissue masses, MR may contribute to recognition of nerve sheath tumors by showing the nerve of origin and typical signal hyperintensity on T2-weighted images. It can also be helpful in distinguishing between schwannomas and neurofibromas by the location of the nerve of origin and the presence of a capsule.

Hydatid disease: MR imaging study.

Fifteen patients with hydatidosis, 13 with hepatic echinococcosis and two with isolated lesions of the spleen and the shoulder, were examined with magnetic resonance (MR) imaging. Of the 13 patients with hepatic hydatidosis, four had secondary peritoneal lesions, and one also had involvement of the dorsal spine. The presence of a hypointense rim and a multiloculated or multicystic appearance are distinctive features. When evaluating the viability of hydatid cysts the authors found that MR imaging findings were not particularly valuable, as the MR imaging signs (daughter cysts and detachment of the membranes) are rare and are also evident at computed tomography and ultrasound examinations. T2 measurements were not useful due to the wide range of values obtained. Despite these limitations, MR imaging is still an important technique in the study of echinococcosis to depict the presence of a rim as a characteristic sign and to obtain a complete anatomic evaluation.

[Magnetic resonance imaging in non-Q wave infarction]. / Localizzazione con risonanza magnetica nucleare dell'infarto non Q.

The aim of this study is to evaluate magnetic resonance (MR) as a clinical tool to identify the site of non-Q myocardial infarction, when other techniques are inadequate. Ten patients underwent MR examination 3 - 15 days after the onset of symptoms. The examinations were performed with a General Electric 1.5 Tesla II unit, by means of ECG-gated MR imaging. The 10 patients were 35 to 56 years of age, 9 were men. In 5 patients it was the first myocardial infarction, in 5 patients the second. MR allowed us to identify the site of myocardial infarction: 5 inferior, 1 posterior, 2 postero-inferior, 1 apical, 2 subendocardial. Thus the MR examination is suggested in non-Q myocardial infarction to detect the site and the extent of the infarct. The MR is useful when echocardiography is technically non adequate or when it is not possible to identify regional wall motion abnormalities. We suggest to use this technique in patients with coronary artery bypass and in patients with multiple infarctions.

Bone marrow infiltration in hairy cell leukemia after interferon therapy detected by magnetic resonance imaging.

Magnetic resonance imaging (MRI) can detect bone marrow infiltration by neoplastic cells in many hematological malignancies. We studied 10 patients affected by hairy cell leukemia (HCL) and treated with interferon (IFN) with both MRI and bone marrow biopsy. T1-weighted MR scans of femurs and pelvis proved to be effective to score hairy cell infiltration, while less information was obtained from the study of the lumbar vertebral column. A good correlation (less than 10% difference) was noted between biopsy and MRI in over 90% of cases. MR scans showed, in general, a higher grade of infiltration. MR scan, however, can be useful for monitoring the course of HCL and the response to the treatment. Moreover, MRI evaluating a large amount of tissue, can detect a nodular type of infiltration which can be missed in biopsy specimens.

[Perinatal cerebral ischemic injury. Neuropathologic bases and correlations with computerized tomography]. / Il danno ischemico cerebrale perinatale. Basi neuropatologiche e correlazioni con la tomografia computerizzata.

The term "hypoxic-ischemic encephalopathy" covers a large part of neonatal neuropathology including the various forms of intracerebral haemorrhage. In the present work the term is confined to ischemic brain edema and actual infarction, be it diffuse or focal. Eighteen newborns with CT evidence of ischemic brain lesions and infarct necrosis were selected. Emphasis is placed on current data on neuropathology of ischemic brain edema and its CT appearance. Particular entities such as periventricular leukomalacia and multicystic encephalopathy are discussed. Relationship between CT and temporal profile of cerebral damage is emphasized in order to predict the structural sequelae and the longterm prognosis.

[Fibrinolytic therapy in acute myocardial infarction. Coronarographic evaluation of short-term results]. / La terapia fibrinolitica nell'infarto miocardico acuto. Valutazione coronarografica dei risultati a breve termine.

The authors report their experience in fibrinolytic therapy with Urokinase in acute myocardial infarction. There were 3 groups of treatment: 100 patients with intracoronary fibrinolytic therapy; 77 patients with peripheral venous fibrinolytic administration; 31 patients with conventional therapy. The 3 groups underwent, between 21 and 28 days after the acute event, a coronarographic examination to evaluate the persistence of patency of the vessels involved in the myocardial infarction. The short term results show that the fibrinolytic therapy (with the limitations due to the hemorrhagic complications associated with the use of Urokinase), especially via intracoronary, is significantly more useful and reliable than conventional therapy, which appears unsatisfactory. Therapeutic failures are probably due to diffuse atherosclerosis of the vessel and/or to the old age of the thrombus.

[Computerized tomography and scintigraphy in the evaluation of osteoid osteoma]. / Tomografia computerizzata e scintigrafia nella valutazione dell'osteoma osteoide.

The authors report their experience of bone scintigraphy and computed tomography in 19 patients, with suspected osteoid osteomas, who underwent surgery. Basing on surgical findings, the role of these techniques in diagnosis, surgical planning and follow-up of osteoid osteoma is stressed and the results are compared with those of conventional radiography.

[Computerized tomography in the study of myelopathy in cervical spondylosis]. / La tomografia computerizzata nello studio della mielopatia da spondilosi cervicale.

This study involved 107 patients selected according to symptoms and signs of myelopathy due to cervical spondylosis. All patients were examined by high resolution CT without intravenous or intrathecal contrast enhancement. Diagnostic accuracy of CT is discussed with regard to idiopathic and degenerative cervical spinal stenosis. Emphasis is placed on CT findings of ossification of posterior longitudinal ligament. The authors conclude that plain CT may be a reliable method for diagnosing cervical spondylothic myelopathy. Nevertheless the authors stress how intrathecal contrast enhanced CT is far superior to plain CT in the selection of a definitive anterior or lateral surgical approach without a delay.

[The use of computerized tomography in recurrences of rectal tumors]. / L'impiego della tomografia computerizzata nell recidive dei tumori rettali.

The authors refer the results of CT studies of 33 patients who underwent surgical resection of the rectum for cancer. In 20 of these cases there was only a suspicion of recurrence; in 13 recurrence had been already clinically or instrumentally demonstrated. In the latter group (13 patients) CT clearly showed the presence of a pelvic mass and of muscular infiltration; in 8 cases pelvic organs and in 7 cases pelvic bones were involved; the mass had liquid density features in 3 patients. In 12 of the 20 cases in which cancer recurrence was suspected, CT demonstrated the presence of a pelvic mass. Compared to the former group infiltration of pelvic organs and bones was less frequent. Granulation tissue, fibrous tissue, abscess formation and surgical removal of epiploon placed into the pelvis may all be causes of false positivity. In order to reduce the rate of wrong diagnosis it is useful a post-operative evaluation of the pelvis as soon as it has recovered from surgery.

[Pierre-Marie's osteoarthropathy: scintigraphic diagnosis during staging of lung cancer]. / Osteoartropatia di Pierre Marie: diagnosi scintigrafica in corso di staging del carcinoma polmonare.

In the last years, total bone scan has gained an important place in the staging of the neoplasms of the lung. Out of 271 patients with lung cancer who underwent a bone scan in the period october 1979-october 1980. 10 showed an increased fixation of the isotope with a linear pattern along the diaphysis of the limbs. These findings, clinically silent, suggested the diagnosis of hypertrophic osteoarthropathy, which has been subsequently confirmed radiologically. The different pathogenetic theories and the evolution of the scintigraphic picture after therapy of the primary disease are briefly discussed.

The radiologic "Target sign" of septic pulmonary embolism in a case of acute myelogenous leukemia.

The authors report the appearance of septic pulmonary embolism in a case of acute myelogenous leukemia. The pulmonary lesions are characterized radiographically by the uncommon appearance of central densities suspended within thin-walled pseudocystic air spaces. A possible pathogenic mechanism explaining these radiographic findings is discussed. Such images must be distinguished from those of a fungus ball or tuberculous cavities.