PubMed Health⌕ Search

Biomedical subjects

Natale Villari

Publications and source records attributed to Natale Villari.

9 recordsLinked to original sources
PubMed2003

Spiral computed tomography versus ultrasound in the follow-up of cirrhotic patients previously treated for hepatocellular carcinoma: a prospective study.

BACKGROUND/AIMS: To assess the value of hepatic-arterial-phase computed tomography (HAP-CT) versus ultrasound (US) plus alpha-fetoprotein (AFP) in the surveillance of cirrhotic patients with previously treated hepatocellular carcinoma (HCC). METHODS: Thirty-six cirrhotic patients, treated for single nodular HCC <4cm with complete response and no evidence of other focal lesions, were enrolled in a prospective study and underwent simultaneous AFP/US/spiral-CT follow-up every 6 months. Focal lesions were considered recurrences when they appeared as globular enhancement areas (EA) at HAP-CT and increased in size during the follow-up. RESULTS: Fifteen of 36 patients showed at least one focal lesion for a total of 43 EA: 38/43 increased in size, four did not change and one disappeared. EA were first observed after a follow-up of 9+/-4 (range 6-18) months. At the same time, no patient had either nodular lesion at US examination or diagnostic levels of AFP. In 22 matched lesions, diagnosis by CT was 8.2+/-3.5 months earlier than by US. In 13 patients, one evolved EA was submitted to US-guided biopsy and histological examination showed HCC in all cases. CONCLUSIONS: Periodical spiral-CT examination is more effective than US-AFP in early detection of HCC recurrence in cirrhotic patients successfully treated for HCC.

Aged↗
PubMed2003

[Meaning and etiopathogenesis of sectorial transient hepatic attenuation differences (THAD)].

PURPOSE: To examine sectoral transient hepatic attenuation differences (THAD) in an attempt to correlate semeiotics with etiopathogenesis and to deduce a possible diagnostic value. MATERIALS AND METHODS: Over a period of three years (January 1998-January 2001) we observed 130 THAD in 988 patients, and we selected 30 sectoral THAD in 18 patients (10 males and 8 females), ranging in age from 24 to 82 years (average = 63.3). The 18 patients comprised 6 cancer patients undergoing CT staging/restaging, 5 cirrhotic patients being studied for possible hepatocellular carcinoma, 7 patients undergoing helical CT to further investigate clinical and/or US findings. For each patient a biphasic helical CT liver examination was performed, during the arterial and portal dominant phase. After the first diagnosis, all patients were followed up for 12 months with at least one US and helical CT examination; 8/18 were also studied by MRI. RESULTS: Thirty THAD were associated with 14 metastatic lesions, 4 hepatocellular carcinomas, 1 cholangiocarcinoma of the liver, 4 haemangiomas, 3 abscesses, 1 FNH, 2 cases of arterioportal shunting (APS) and 1 fine-needle percutaneous biopsy. Nine THAD turned out to be the sole sign of disease and occurred at least 3/6 months before the causal focal lesion had become detectable. At the first examination, all focal lesions had a maximum diameter of 2 cm; the size of THAD varied from 1 to 5 cm. All of the THAD were sectoral, with the base side represented by the glissonian capsule and the apex towards the parenchyma. 27/30 THAD were connected to focal lesions: 24/27 were fan-shaped and the lesion was situated at the apex of the triangle; 3/27 were roughly wedge-shaped and the lesion was entirely inscribed in the hyperattenuating area. 3/30 were not connected to focal lesions, being in 2 cases fan-shaped and in only one case irregularly shaped. CONCLUSIONS: Sectoral THAD may or may not be connected to focal lesions. Whenever a sectoral THAD not connected to a focal lesion is detected, all of the possible causes should be considered: portal or superhepatic vein thrombosis, traumatic (biopsy) or cirrhotic intraparenchymal APS, or a benign occult nodule. If none of these explanations are confirmed, we should consider the possibility of an occult malignant lesion.

Adult↗
PubMed2002

Whole brain apparent diffusion coefficient histogram: a new tool for evaluation of leukoaraiosis.

PURPOSE: To test whole brain apparent diffusion coefficient histogram analysis as an alternative approach to visual score for the assessment of leukoaraiosis (LA). MATERIALS AND METHODS: T2 and diffusion weighted images were obtained in 15 elderly patients. LA extension was assessed on T2 weighted images by two observers using a semiquantitative visual score. Apparent diffusion coefficient (ADC) maps of the entire brain were generated and, after exclusion of the skull with manual tracing and of the cerebrospinal fluid (CSF) by application of a threshold value, whole brain (WB)-ADC histogram was obtained. Moreover, a brain volume index (BVI) was calculated on ADC maps as (intracranial volume - CSF volume) /intracranial volume. RESULTS: The kappa inter-observer agreement for LA scoring was 0.69. Manual segmentation of the skull showed a mean inter-operator coefficient of variation below 3%. The median value of whole brain ADC histogram directly correlated with LA extension (P = 0.013). Moreover a significant inverse correlation (P = 0.002) was found between WB-ADC median value and BVI. CONCLUSION: WB-ADC histogram is a reproducible alternative tool for assessing LA extension and severity.

Aged↗
PubMed2002

Single-voxel long TE 1H-MR spectroscopy of the normal brainstem and cerebellum.

PURPOSE: To evaluate the feasibility of single voxel 1H-MRS of the CNS structures contained in the posterior cranial fossa and to determine the distribution of the normal metabolite ratios, concentrations, and T2 relaxation times in the midbrain, pons, medulla, dentate nucleus and cerebellar vermis. MATERIALS AND METHODS: A total of 147 single voxel 1H-MR spectra with a point-resolved proton spectroscopy sequence (PRESS) sequence and echo time (TE) of 136 or 272 msec were obtained in the midbrain, pons, medulla, dentate, and vermis of 31 healthy volunteers. In seven additional patients; the concentrations and T2 relaxation times of metabolites were obtained in the same locations (except the medulla) with an external phantom calibration method and a four TE PRESS technique. RESULTS: Ten (27%) of 36 spectra acquired in the medulla were of poor quality. A similar ranking of the N-acetyl aspartate (NAA)/creatine (Cr) ratio and choline(Cho)/Cr ratios in the five locations for the two TEs was observed, with the highest values in the pons (mean NAA/Cr = 4.16 +/- 0.6 and Cho/Cr =2.66 +/- 0.6 at TE 272) and the lowest values in the dentate and vermis (mean NAA/Cr = 1.66 +/- 0.2 and Cho/Cr = 1.20 +/- 0.2 at TE 272). The analysis of variance showed significant regional differences of the NAA and Cr concentrations, which had the highest values in the dentate. Non-significant regional differences were observed for the concentration of Cho and for the T2 of the metabolites. CONCLUSION: With the exception of the medulla, single voxel 1H-MRS enables an in vivo biochemical analysis of the CNS structures contained in the posterior cranial fossa. Regional differences in the metabolite ratios and concentrations must be considered when employing 1H-MRS for evaluation of diseases of the brainstem and cerebellum.

Adult↗
PubMed2002

Proton MR spectroscopy of the cerebellum and pons in patients with degenerative ataxia.

PURPOSE: To investigate whether proton magnetic resonance (MR) spectroscopy is a useful complement to MR imaging in patients with degenerative ataxia. MATERIALS AND METHODS: Brain MR imaging and single-voxel proton MR spectroscopy of the right cerebellar hemisphere and pons were performed in 30 patients with sporadic (n = 16) or inherited (n = 14) degenerative ataxia and in 20 healthy control subjects. Several indexes of brainstem and cerebellar atrophy were measured on MR images, as well as the N-acetylaspartate/creatine (NAA/Cr), choline/Cr (Cho/Cr), and myo-inositol/Cr (mI/Cr) ratios in the MR spectra. Differences between patients and subjects were evaluated with the Kruskal-Wallis and Mann-Whitney tests, whereas correlation of clinical, MR imaging, and spectroscopic data was assessed with nonparametric Spearman rank correlation. RESULTS: Measurements of brainstem and cerebellar atrophy obtained from MR images revealed patients had olivopontocerebellar atrophy (OPCA) (n = 11), spinal atrophy (SA) (n = 8), or corticocerebellar atrophy (CCA) (n = 4). Seven patients did not fulfill the criteria for any group and were considered undefined. In patients with OPCA, the pontine and cerebellar NAA/Cr and Cho/Cr ratios were significantly decreased when compared with those of the control subjects. Pontine and cerebellar NAA/Cr ratios were also significantly reduced in patients with SA and CCA. Five patients with undefined ataxia had a substantial decrease of pontine or cerebellar NAA/Cr ratio when compared with that of the control subjects. In patients with OPCA, the pontine NAA/Cr ratio (but not the atrophy measurements) showed a correlation (P =.04) with disability. CONCLUSION: MR spectroscopy is a useful complement to MR imaging in patients with degenerative ataxia.

Adolescent↗
PubMedDate not supplied

Comparison of spirometric-gated and -ungated HRCT in COPD.

PURPOSE: The purpose of this work was to evaluate feasibility of spirometric-gated high-resolution computed tomography (HRCT) in patients with chronic obstructive pulmonary disease (COPD) and to compare the lung density CT measurements obtained with and without spirometric control of lung volume. METHOD: Twenty-nine patients with COPD underwent pulmonary function tests and spirometric-gated (3 slices at 10% and 90% of vital capacity) and -ungated (12 slices at maximum expiration and inspiration) HRCT in the same day. Four lung density measurements (inspiratory pixel index, expiratory pixel index, inspiratory and expiratory mean lung density) derived from gated and ungated acquisitions were compared using the nonparametric Wilcoxon test, the line of equality, and the Bland and Altman test. RESULTS: The vital capacity measured at pulmonary function tests and on the CT table showed a substantial agreement. All but one patient completed the gated and ungated examination, but only 8 (28%) of 28 patients reached the expiratory and inspiratory gating level for CT acquisitions at the first attempt. Only the inspiratory mean lung density derived from the 3 gated and 12 ungated slices showed borderline agreement. Other CT measurements, and notably all those from the 3 gated and ungated scans, acquired at the same anatomic level, did not agree. CONCLUSIONS: Although the procedure can be difficult for individual patients, spirometric gating significantly influences the lung density CT measurements and might improve standardization of CT evaluation of COPD.

Feasibility Studies↗
PubMedDate not supplied

Proton MR spectroscopy of Wernicke encephalopathy.

Two patients with acute thiamine deficiency were examined with thalamic single-voxel proton MR spectroscopy. T2-weighted images exhibited increased signal intensity. N-acetylaspartate (NAA)/creatine (Cr) ratios were low without detectable lactate. Owing to substantially decreased choline (Cho) T2, the Cho/Cr ratio was not decreased. After thiamine therapy, the NAA/Cr ratio increased, paralleling clinical improvement and reduction in the areas of signal-intensity changes.

Humans↗