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G C Magri

Publications and source records attributed to G C Magri.

5 recordsLinked to original sources
PubMed2001

Gated blood pool tomography for the evaluation of global and regional left ventricular function in comparison to planar techniques and echocardiography.

BACKGROUND: Multigated radionuclide ventriculography (MUGA) is a simple and reliable tool for the assessment of global systolic and diastolic function and in several studies it is still considered a standard for the assessment of left ventricular ejection fraction. However the evaluation of regional wall motion by MUGA is critical due to two-dimensional imaging and its clinical use is progressively declining in favor of echocardiography. Tomographic MUGA (T-MUGA) is not widely adopted in clinical practice. The aim of this study was to compare T-MUGA to planar MUGA (P-MUGA) for the assessment of global ejection fraction and to transthoracic echocardiography for the evaluation of regional wall motion. METHODS: A 16-segment model was adopted for the comparison with echo regional wall motion. For each one of the 16 segments the normal range of T-MUGA ejection fraction was quantified and a normal data file was defined; the average value -2.5 SD was used as the lower threshold to identify abnormal segments. In addition, amplitude images from Fourier analysis were quantified and considered abnormal according to three different thresholds (25, 50 and 75% of the maximum). RESULTS: In a study group of 33 consecutive patients the ejection fraction values of T-MUGA highly correlated with those of P-MUGA (r = 0.93). The regional ejection fraction (according to the normal database) and the amplitude analysis (50% threshold) allowed for the correct identification of 203/226 and 167/226 asynergic segments by echocardiography, and of 269/302 and 244/302 normal segments, respectively. Therefore sensitivity, specificity and overall accuracy to detect regional wall motion abnormalities were 90, 89, 89% and 74, 81, 79% for regional ejection fraction and amplitude analysis, respectively. CONCLUSIONS: T-MUGA is a reliable tool for regional wall motion evaluation, well correlated with echocardiography, less subjective and able to provide quantitative data.

Echocardiography↗
PubMed1992

A motion correction algorithm for an image realignment programme useful for sequential radionuclide renography.

The correction of organ movements in sequential radionuclide renography was done using an iterative algorithm that, by means of a set of rectangular regions of interest (ROIs), did not require any anatomical marker or manual elaboration of frames. The realignment programme here proposed is quite independent of the spatial and temporal distribution of activity and analyses the rotational movement in a simplified but reliable way. The position of the object inside a frame is evaluated by choosing the best ROI in a set of ROIs shifted 1 pixel around the central one. Statistical tests have to be ful-filled by the algorithm in order to activate the realignment procedure. Validation of the algorithm was done for different acquisition set-ups and organ movements. Results, summarized in Table 1, show that in about 90% of the simulated experiments the algorithm is able to correct the movements of the object with a maximum error less or equal to 1 pixel limit. The usefulness of the realignment programme was demonstrated with sequential radionuclide renography as a typical clinical application. The algorithm-corrected curves of a 1-year-old patient were completely different from those obtained without a motion correction procedure. The algorithm may be applicable also to other types of scintigraphic examinations, besides functional imaging in which the realignment of frames of the dynamic sequence was an intrinsic demand.

Algorithms↗
PubMed1989

Comparison of results of skin prick tests (with fresh foods and commercial food extracts) and RAST in 100 patients with oral allergy syndrome.

One hundred adult patients with a history of oral allergy syndrome (OAS) after ingestion of fruits and vegetables, 77 patients with hay fever and 13 with skin prick tests and RAST positive to pollens but without seasonal symptoms, and 32 normal nonallergic control subjects, had Phadebas RAST and skin prick tests with commercial extracts (CSPT) and with fresh foods (FFSPT) to assess the reliability of these three tests. Sensitivity was better with FFSPT for carrot, celery, cherry, apple, tomato, orange, and peach; better with CSPT for peanut, pea, and walnut; and better with RAST for hazelnut. Specificity, negative predictive value, and positive predictive value of the three tests were determined for apple, carrot, hazelnut, orange, pea, peanut, and tomato. Specificity in the patient groups ranged between 40% (pea) and 100% (apple) for CSPT, between 61% (peanut) and 87% (carrot) for RAST, and between 42% (carrot) and 93% (peanut) for FFSPT. However, all tests were negative in the control group. Thus, false positive results may result from cross-reactivity with pollen allergens. The diagnostic accuracy of these tests in the population with OAS proved comparable for peanut, carrot, hazelnut, and pea. FFSPT proved more sensitive than CSPT or RAST in confirming a history of OAS to certain alimentary allergens, such as apple, orange, tomato, carrot, cherry, celery, and peach.

Adolescent↗
PubMedDate not supplied

Sentinel node biopsy in melanoma: the experience of Brescia Civic Hospital.

The accuracy of the sentinel node (SN) technique in the evaluation of lymph node involvement in melanoma was evaluated in 71 consecutive patients with localized disease and Breslow index >1 mm. Lymphoscintigraphy identified at least one SN in 70 of the 71 patients (98.5%). The following day 69 patients underwent selective SN excision. The SN was identified by portable probe. One hundred and twenty-two lymph nodes were removed, 14 (11.4%) of which were metastatic in 9 patients (13%). No metastases were found in 40 patients with Breslow <2 mm. Eight of the 9 patients with positive SNs underwent lymphadenectomy of the whole basin and in two patients new metastatic nodes were found. At 4-26 months' follow-up 1 of the 60 patients with negative SN (scalp melanoma with Breslow 6.2 mm) developed bilateral cervical metastatic nodes. Two more patients with Breslow 3.7 and 5 mm, respectively, developed liver and lung metastases. The remaining 57 patients are still disease free. Among the 9 patients with tumor-positive SNs, 1 was lost to follow-up, 3 died and 5 are still alive. Our data confirm the clinical reliability of the SN technique in melanoma; we feel the technique should be considered a standard tool in the evaluation of melanoma patients.

Adolescent↗