Biomedical subjects

P Ercolani

Publications and source records attributed to P Ercolani.

26 records · Page 2Linked to original sources

PubMedDate not supplied

MRI in characterization of focal liver lesions: comparison of T2 weighting by conventional spin-echo and turbo spin-echo sequences.

Forty-one patients with 61 proved focal liver lesions underwent MRI of the liver at 1.0 T, with the aim of evaluating the usefulness of turbo spin-echo (TSE) sequences in characterizing focal liver lesions, by comparing them with conventional spin-echo (CSE) sequences. Two different TSE protocols were employed. with constant echo time and varying repetition time: TSE-S (3000 msec) and TSE-L (5100 msec). All images were evaluated quantitatively (signal-to-noise ration 'SNR') and qualitatively: because benign lesions were all liquid (12 cysts and 10 hemangiomas), they were well characterized morphologically on the basis of signal intensity. Mean SNR was significantly different between metastases and benign lesions (P < .0001) with all T2 sequences. Among the single T2 sequences tested, logistic regression analysis showed TSE-L to have the best predictive ability of the nature of focal lesions, with a G value of 42.02, compared to 29.87 of TSE-S and 25.55 of CSE second echo (SE II). The combination of TSE-L with TSE-S did not modify these results, whereas the combination of TSE-L with CSE only resulted in slight improvement (G = 46.95). Comparison of the receiver operating characteristic (ROC) curves showed only SE II (area under the ROC curve of .8312) to be significantly inferior to the best single sequence, or TSE-L (area under the ROC curve of .9176; P = .027). All sequences were equivalent in qualitative evaluation with good reproducibility, sensitivity ranging from .94 to 1.0 and specificity ranging from .86 to .93. This study confirms the value of TSE sequences in characterization of focal liver lesions. Time of acquisition is strongly reduced with these sequences, whereas results are fairly similar to those obtained with CSE. TSE sequences could therefore replace CSE for the study of focal liver lesions.

Adult↗

PubMedDate not supplied

MR imaging of focal liver lesions: comparison between turbo spin-echo and conventional spin-echo pulse sequences.

The aim of this study was to compare conventional spin-echo (CSE) T2-weighted (T2W) images with turbo spin-echo (TSE) T2W pulse sequences in their ability to detect focal liver lesions. Seventy-eight consecutive patients with focal liver lesions were entered into this study. All patients were imaged using the gradient-echo (GE) sequence with the breath-hold technique for T1-weighted (T1W) images, and CSE and TSE sequences for T2W images. Qualitative evaluation included lesion detection (number of lesions detected) and conspicuity (extent of visualization of lesional borders); quantitative evaluation included the signal-to-noise (S/N) ratio and the contrast-to-noise (C/N) ratio. TSE showed the best performance in terms of lesion detection; however, the difference between TSE and CSE was significant only in the case of benign cysts (p < 0.01). Conspicuity was higher with TSE and CSE, and lower with GE. The S/N and C/N ratios of the two T2W sequences were also comparable, and better than those of GE. However, the combined use of GE and TSE resulted in improved lesion detection. The results show that, because the acquisition time is greatly reduced with TSE sequences, these should be considered as first-line approach to magnetic resonance imaging of the liver for the study of focal lesions.

Adenoma↗

PubMedDate not supplied

Evaluation of the pulmonary artery by cine MRI.

Twenty-four patients whose mediastinal (12 patients) and lung (12 patients) neoplasms were eventually verified were evaluated with cine MRI in addition to conventional methods (plain radiography, CT, MRI, and endoscopy). Using a 1.0 T system and gradient echo (FLASH repetition time 250-350 ms, echo time 12, flip angle 25-60 degrees) multislice pulse sequence, cine MRI was performed combined with cardiac gating. At the level of the pulmonary artery, the CT, spin echo (SE) MRI, and cine MRI findings were evaluated blindly by three groups of radiologists to determine whether the pulmonary artery was infiltrated or dynamically stenotic. Cine MRI allowed an overall diagnostic accuracy of 100% in comparison with SE MRI (91.6%) and CT (91.6%).

Adolescent↗

PubMedDate not supplied

[Cine-MR in the assessment of the cardiovascular structures in extensive mediastinal pathology].

The authors report their experience with cine-MRI in evaluating the infiltration of the main cardiovascular structures by expansive mediastinal masses. Twenty-four patients with proven lung (12 cases) and mediastinal (12 cases) cancers, previously selected with CT, underwent MRI examination of the chest. A superconductive 1.0 T unit was employed. Cytohistologic confirmation was obtained in all cases (6 thymomas, 6 lymphomas, 12 lung cancers). Ten normal subjects were also studied as a control group. Axial, coronal, and sagittal SE T1 images were obtained as the basis for MRI investigation of the chest. Subsequently, gradient-echo pulse-sequences images were obtained during the whole cardiac cycle, and later displayed on cine-Mode, on the section plane where vessel wall was closest to the tumor. The results prove cine-MRI to allow a correct diagnosis to be made in all cases, especially in those patients where CT and conventional SE MRI yielded questionable results. This preliminary experience suggests that cine-MRI could be used as a complementary method to CT and conventional SE MRI in evaluating mediastinal vessel involvement.

Adolescent↗

PubMedDate not supplied

MR imaging of rheumatoid hand lesions: comparison with conventional radiology in 31 patients.

The purpose of this study was to evaluate the diagnostic accuracy of magnetic resonance imaging (MRI) in rheumatoid arthritis (RA) by comparing MRI with conventional radiology (CR) findings and by correlating these findings with the clinical and serological profile of the disease. The hands of 31 patients (24 females, 7 males) affected by classical RA were studied using a Magnetom 1.0 T tomograph. Coronal, axial, and/or sagittal SE T1 and GE (FLASH 2D FL: 70 degrees-15 degrees) images were obtained in all patients. Moreover, in 7 patients the MRI study was performed after i.v. injection of Gd DTPA contrast medium (0.2 mM/kg). Ten healthy volunteers were also studied as controls. In all patients a conventional radiological study was performed as well as a clinical and serological investigation. Two blinded observers evaluated the MRI and CR findings and checked 15 elementary pathological lesions, assigning an MRI and a CR score to each patient. MRI provided higher accuracy than CR in detecting rheumatoid soft tissue changes and minimal skeletal lesions, while the opposite was true for severe skeletal lesions. No correlations emerged between the MRI/CR findings and clinical and serological data. This study suggests that MRI and CR are complementary techniques in the evaluation of the anatomical changes in RA.

Adult↗

PubMedDate not supplied

[Magnetic resonance in the tunnel carpal syndrome. Possibilities and perspectives of an etiopathogenetic study].

Thirty-four selected patients were evaluated in order to define MRI capabilities in the preoperative evaluation and characterization of the pathogenetic patterns of carpal tunnel syndrome (CTS). MRI examinations were performed by means of a superconductive unit (1.0 T, Magnetom): SE T1 (500/17) and T2 (2000/90) axial images of the carpal region were obtained with a round surface coil. In 8 patients 3D GE (FLASH) pulse sequences were used to obtain 32 images of the hand; 3D reconstruction was also applied. Six patients with rheumatoid arthritis and amyloidosis were also studied after i.v. injection of Gd-DTPA (0.2 mM/kg). MRI findings were compared with both clinico-electrophysiologic and surgical results. High agreement was observed only between MRI and surgical findings. MRI allowed the direct demonstration of carpal tunnel abnormalities in 8 cases, while abnormal findings in the median nerve were observed in 18 patients. The possibility of depicting medial nerve lesions on T2-weighted images when no direct demonstration of the cause of compression is possible, could represent a guideline for the etiopathogenetic investigation of CTS. However, further experience in selected patients is necessary to define all the aspects relative to this very common syndrome.

Adult↗

PubMedDate not supplied

[The use of the Daylight System in mammography].

It is widely known that Daylight film handling has yielded several benefits to diagnostic radiology, that is, reduction in exam duration, thus improving both efficiency and productivity; space saving in departments, by minimizing darkroom spaces; improved working conditions for the staff. This paper reports on the study of the application of a Daylight system to mammography. For this purpose, the authors used an X-ray unit (Senographe 500 T-CGR) and a Dupont Daylight unit, whose diagnostic yield was compared to that of "vacuum" and cassettes units. The results of our experience confirmed the well-known advantages DDS yields to diagnostic radiology. In particular, the use of Daylight rather than vacuum system allowed a considerable reduction in exam duration (10 to 2 minutes). Moreover, the new Dupont screen-film system allowed a reduction in average whole breast dose by about 28% if compared to the conventional recording system employed in our department. Mammograms with high contrast resolution, sensitivity, and good spatial resolution were thus obtained, as shown in the analysis of quality image. The Daylight system allowed a marked improvement to be made in efficiency, productivity, and organization, as well as a reduction in whole breast dose and high-quality mammographic images.

Evaluation Studies as Topic↗

PubMedDate not supplied

[Magnetic resonance versus traditional breast imaging in solid nodular diseases of the breast].

We report and compare the results obtained with conventional imaging (mammography and US) and MRI in the study of 46 solid nodular breast lesions verified with histologic, cytologic and/or instrumental follow-up examinations for 12-34 months. The variables we compared were relative to the identification, nature and size of the lesions. MRI, which was performed on the basis of previous mammographic and US findings, detected all the lesions but never modified the diagnosis of conventional imaging methods. Questionable MR diagnoses were fewer than mammographic and US ones (2 versus 11), but its role in correcting the questionable diagnoses of conventional imaging methods was controversial. Particularly, of 11 such cases on mammographic and US images, MRI made 8 correct diagnoses but exhibited 2 false positives and 1 false negative for carcinoma. Such MR mistakes are likely to be related to the non-use of contrast medium. As for size, US was more accurate than mammography and MRI; yet, very few misdiagnoses were make on the whole.

Adolescent↗