[Study of prostatic carcinoma with ultrasonography and magnetic resonance with "dedicated" surface coil]. / Studio del carcinoma prostatico mediante ecografia e Risonanza Magnetica con bobina di superficie dedicata.

We investigated the role of an experimental surface coil for low field (0.2 T) MRI of prostatic gland carcinoma; the study was performed comparing MRI with US findings and with bioptic and pathologic results. To this purpose, 16 patients with prostatic cancer suspected at US and demonstrated with US-guided biopsy, were examined with low intensity field (0.2 T) MRI performed with a dedicated saddle-shaped coil and a body coil. This experimental surface coil with perineal application is used to study the prostatic gland with low field MR equipment where no transrectal probe is available. We analyzed the results of this study and found that, in all patients but one, the neoplastic lesions exhibited low signal intensity on T2-weighted images, while the normal gland was hyperintense. Six patients underwent radical prostatectomy and diagnostic imaging findings were correlated with pathologic findings obtained with whole mount specimens and serial histologic slides. The number of tumor foci, their site and size, and stromal reaction were studied on T2-weighted images; the typical low signal intensity was absent in one of 16 patients, in which case the microscopic exam of pathologic specimens showed extensive tumor spread with infiltration of perineural lymphatic vessels, with neither nodular patterns nor stromal reactions. The correlation between MR findings and the whole mount specimens (n = 6) demonstrated MR underestimation of tumor spread. In our opinion, this technique is useful for the detection and characterization of prostatic lesions, in spite of the presence of isointense lesions and the risk of underestimating the disease, especially to the prostatic capsule. To conclude, the dedicated surface coil can improve the diagnostic accuracy of low field MRI.

[Invasive aspergillosis in the hematologic patient: the usefulness of computed tomographic and high-resolution computed tomographic studies]. / Aspetti dell'aspergillosi invasiva nel paziente ematologico: utilità dello studio mediante Tomografia Computerizzata e Tomografia Computerizzata ad alta risoluzione.

Invasive aspergillosis is an emerging cause of death in hematologic patients. Several patterns of lung involvement are described: acute tracheobronchitis, bronchopneumonia, pleural aspergillosis and angioinvasive aspergillosis. The latter pattern is the most common one; it is characterized by different signs, some of which, supported by clinical data, are quite suggestive for fungal etiology. Particularly, nodules and/or wedge-shaped lesions with a ground-glass halo are a useful early feature, best detected by HRCT. Early therapy with amphotericin B may improve survival chances. Therefore, in neutropenia patients we decided, when possible, to perform high-resolution computed tomography (HRCT) as soon as fever appears. This was feasible in 8 of 32 patients with invasive aspergillosis examined with HRCT. Immediate treatment with amphotericin B in one such patient showing a nodule with the halo sign allowed the lesion to completely disappear. The authors describe the frequency of different radiologic signs in 32 patients, as observed in 54 HRCT exams; the results are compared with those obtained with conventional CT and chest X-ray. Compared to chest X-ray, CT detects more lesions and is more sensitive to small pneumothorax and minimal pleural effusion or thickening. HRCT is more suitable to detect initial cavitation and thin ground-glass haloes.

[Magnetic resonance features in cerebral primary lymphomas in non-immunocompromised subjects]. / Aspetti della Risonanza Magnetica nei linfomi primitivi cerebrali nei soggetti non immunocompromessi.

In the past few years, non-Hodgkin's lymphomas have been paid increasing attention to because of their recently increasing frequency. We reviewed the MR images of 17 patients with histologically proved primary CNS lymphoma, all of them immunocompetent at diagnosis. We studied the site, number and shape of the lesions, the presence and grade of edema and possible periventricular spread. The exams were performed with 0.5 T and 1.5 T MR units, using SE sequences on the sagittal, axial and coronal planes, before and after Gd-DTPA administration. The most typical neuroradiologic signs which may suggest the diagnosis of CNS lymphoma are deep or periventricular lesion site, diffuse and marked contrast enhancement, poorly defined borders, moderate edema surrounding the mass and a tendency to periventricular spread. MRI demonstrated 35 lesions in 17 patients. The lymphoma was unifocal in 9 cases (53%) and 7 lesions were localized in subtentorial site. Lesion size did not exceed 2 cm in 49% of cases, ranged 2-4 cm in 40% and exceeded 4 cm in 11% of cases only. These lesions and hypo- to isointense on T1-weighted images (97%) and their signal intensity varies on T2-weighted images, with mainly iso-/hypointense patterns (79%). All lesions enhanced after Gd-DTPA administration, 74% of them markedly and 26% moderately; enhancement was mostly homogeneous (80% of cases). Perilesional edema was observed in 74% of cases. In conclusion, MRI yields some useful information for the diagnosis of primary CNS lymphoma, but the clinical and radiologic signs of this lesion may exhibit aspecific signal features, meaning that no correct diagnosis can be made even in immuno-competent patients.

[Magnetic resonance imaging in denervated muscle. A preliminary study]. / Imaging con risonanza magnetica nel muscolo denervato. Studio preliminare.

Ten patients with various forms of peripheral neuropathy and spinal radiculopathy were examined with MRI using a low-field permanent magnet (0.2 T) and spin echo (SE)/inversion recovery (IR) sequences, with an adequate inversion time to suppress healthy muscle signal. In acute denervation MR sensitivity was low on both sequences; in subacute denervation the damaged muscle was more intense than the healthy muscle only on IR sequences. MRI adequately depicted fatty infiltration in chronic denervation. In conclusion, MRI is a promising tool for mapping and noninvasively monitoring denervated motor units in skeletal muscles, whose role is currently complementary to that of electromyography.

[Computerized tomography assessment of bone damage following injury of the anterior cruciate ligament]. / Valutazione con Tomografia Computerizzata del danno osseo conseguente a lesione del legamento crociato anteriore.

An ACL tear causes an anterior subluxation of the tibial bone which rotates with its fulcrum on the medial collateral ligament; consequently, the lateral femoral condyle impacts on the external tibial plateau. The presence of a subcortical lesion of the spongiform bone in the posterior external tibial plateau is an indirect sign of an ACL tear. On MR images, traumatic changes are depicted as changes in bone marrow signals. To assess the diagnostic capabilities of CT in demonstrating the bone lesion subsequent to ACL trauma, 23 patients with positive MR exams of the knee were submitted to CT. Fifteen patients had complete ACL tears, 8 had partial tears and 20 exhibited an occult fracture of the posterior portion of the external tibial plateau. This study pointed out a significant correlation between ACL tears and changes in the spongiform structure of the posterolateral tibial plateau. Such changes are depicted not only by MRI but also by CT: the latter method is also a valuable tool to study these conditions long after the traumatic event. No more than 5 slices, 1-1.5 mm thick, acquired at the tibial plateau allowed the trabecular structure and its abnormal changes to be studied without markedly lengthening examination time.