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Biomedical subjects

C Di Maggio

Publications and source records attributed to C Di Maggio.

At least 19 recordsLinked to original sources
PubMed2006

Evaluation of the minimum iodine concentration for contrast-enhanced subtraction mammography.

Early manifestation of breast cancer is often very subtle and is displayed in a complex and variable pattern of normal anatomy that may obscure the disease. The use of dual-energy techniques, that can remove the structural noise, and contrast media, that enhance the region surrounding the tumour, could help us to improve the detectability of the lesions. The aim of this work is to investigate the use of an iodine-based contrast medium in mammography with two different double exposure techniques: K-edge subtraction mammography and temporal subtraction mammography. Both techniques have been investigated by using an ideal source, like monochromatic beams produced at a synchrotron radiation facility and a clinical digital mammography system. A dedicated three-component phantom containing cavities filled with different iodine concentrations has been developed and used for measurements. For each technique, information about the minimum iodine concentration, which provides a significant enhancement of the detectability of the pathology by minimizing the risk due to high dose and high concentration of contrast medium, has been obtained. In particular, for cavities of 5 and 8 mm in diameter filled with iodine solutions, the minimum concentration needed to obtain a contrast-to-noise ratio of 5 with a mean glandular dose of 2 mGy has been calculated. The minimum concentrations estimated with monochromatic beams and K-edge subtraction mammography are 0.9 mg ml(-1) and 1.34 mg ml(-1) for the biggest and smallest details, respectively, while for temporal subtraction mammography they are 0.84 mg ml(-1) and 1.31 mg ml(-1). With the conventional clinical system the minimum concentrations for the K-edge subtraction mammography are 4.13 mg ml(-1) (8 mm diameter) and 5.75 mg ml(-1) (5 mm diameter), while for the temporal subtraction mammography they are 1.01 mg ml(-1) (8 mm diameter) and 1.57 mg ml(-1) (5 mm diameter).

Algorithms↗
PubMed2002

The Italian multi-centre project on evaluation of MRI and other imaging modalities in early detection of breast cancer in subjects at high genetic risk.

This report presents the preliminary results of the first phase (21 months) of a multi-centre, non-randomised, prospective study, aimed at evaluating the effectiveness of contrast-enhanced magnetic resonance imaging (MRI), X-ray mammography (XM) and ultrasound (US) in early diagnosis of breast cancer (BC) in subjects at high genetic risk. This Italian national trial (coordinated by the Istituto Superiore di Sanità, Rome) so far recruited 105 women (mean age 46.0 years; median age 51.0; age range 25-77 years), who were either proven BRCA1 or BRCA2 mutation carriers or had a 1 in 2 probability of being carriers (40/105 with a previous personal history of BC). Eight cases of breast carcinomas were detected in the trial (mean age 55.3 years, median age 52.5; age range 35-70 years; five with previous personal history of BC). All trial-detected BC cases (8/8) were identified by MRI, while XM and US correctly classified only one. MRI had one false positive case, XM and US none. Seven "MRI-only" detected cancers (4 invasive, 3 in situ) occurred in both pre- (n = 2) and post-menopausal (n = 5) women. With respect to the current XM screening programmes addressed to women in the age range 50-69 years, the global incidence of BC in the trial (7.6%) was over ten-fold higher. The cost per "MRI-only" detected cancer in this particular category of subjects at high genetic risk was substantially lower than that of an XM-detected cancer in the general women population. These preliminary results confirmed that MRI is a very useful tool to screen subjects at high genetic risk for breast carcinoma, not only in pre-, but also in post-menopausal age, with a low probability of false positive cases.

Adult↗
PubMed2001

Evidence of a cohort effect for age at onset of schizophrenia.

OBJECTIVE: The authors address whether a possible age-at-onset cohort effect may have introduced a bias into anticipation studies of schizophrenia. METHOD: A retrospective review of the medical records of all admissions for psychotic disorders (N=877) was conducted. All subjects with a confirmed DSM-IV diagnosis of schizophrenia and age-at-onset data were included (N=419). For analyses, subjects were placed into one of three successive birth cohorts: 1905-1944 (N=96), 1945-1964 (N=200), and 1965-1984 (N=123). RESULTS: The mean age at first appearance of psychotic symptoms and, similarly, the mean age at first hospitalization significantly decreased over time in successive birth cohorts (25.3, 23.3, and 20.4 years, respectively, for age at first appearance of psychotic symptoms). CONCLUSIONS: This potential birth cohort effect for age at onset of schizophrenia needs to be incorporated into genetic models.

Adult↗
PubMed1999

[Proficiency test in clinical mammography. Results of a consecutive series of 130 volunteer Italian radiologists].

PURPOSE: We evaluated the results obtained by 130 Italian radiologists undergoing a proficiency test of clinical mammography. MATERIAL AND METHODS: Radiologists were invited to report a series of 100 mammograms (two views), including 32 cancers and 78 non-cancers, with limited information regarding age, subjective symptoms, and findings at palpation. Sensitivity and specificity were then calculated. The test was validated by a panel of experts, and standards for test sufficiency were established on that basis (sensitivity > 80%, specificity > 85%). The tested radiologists differed by mammographic practice (average = 5.7 years, range 0.5-18), total number of mammograms read (average = 8,784, range 300-50,000) and per year (average = 1,535 range 300-5,000). RESULTS: Sensitivity (standard > 80%, average 81.1%, range 39-100%) and specificity (standard > 85%, average 84.0%, range 38-98%) standards were reached by 79 (60.8%) and 81 (62.3%) radiologists, respectively. Overall, only 37 (28.5%) radiologists passed the test (reached both standards). Mammographic practice (years of experience) (chi 2 for trend 5.26, p = 0.02), total mammograms read (chi 2 5.86, p = 0.05), and mammograms read per year (chi 2 8.07, p = 0.01) significantly correlated with a sufficient test. DISCUSSION: The evaluated sample is rather large but not necessarily representative of Italian radiologists. Had the sample been selected, there is no way to know if the results would have been biased towards a better or worse figure with respect to the national average. A significant correlation was found with reading experience (the best results were obtained by operators with > 10,000 films read and with > 2,000 films read/year), as which is important because most Italian radiologists reporting mammography usually read a limited number of cases. CONCLUSIONS: These results on such a wide sample of radiologists, possibly representative of the national average, are disappointing, and suggest that the average quality of mammography reporting in Italy may not be up to standards. Thus, we suggest that quality control program for clinical mammography not only test the equipment but include training and accreditation of radiologists.

Clinical Competence↗
PubMed1996

[Quality control of mammography: potential use of a new device for testing the image quality and the dose].

The authors tested a new equipment containing a phantom to check quality mammographic image and an electronic instrument to measure incident radiation (Phan-EX). The phantom contains objects which have similar characteristics to the details of diagnostic interest and allows an easy and accurate estimation of image quality on the basis of the number of objects detected. The radiation detector, consisting of a solid state photodiode, provides an integer proportional to the input exposure. The results obtained highlighted a good reproducibility of instrument output and a good relationship between these values and the exposure ones obtained with a much more expensive ionization chamber. The device response was linear in varying both the anodic exposure (mAs) and the x-ray tube voltage (varying the energy, the calibration factor varied only by a small percent). The authors conclude that the Phan-EX may be useful for quality assurance of the mammographic unit. Furthermore, they suggest some of its practical applications: daily tests of qualitative of the mammographic unit and the treatment system performance, control of the automatic exposure probe, choice and optimization of exposure and treatment of the film parameters, the determination of the output of the x-ray tube, the evaluation of the sensitivity of different screen/film systems.

Equipment Design↗
PubMed1996

[The ankle and hindfoot of rheumatoid arthritis patients: study with computerized tomography].

To study ankle and hindfoot involvement, we used Computed Tomography (CT) in 38 rheumatoid arthritis (RA) patients (32 women, 6 men, mean age: 56.3 +/- 10.1 years, mean disease duration: 9.9 +/- 6 years) all presenting a definite clinical disease of these joints. The scans were performed on 3rd generation CT equipment (GE ProSpeed SX), with coronally oriented scans 3 mm thick. Bone erosions and joint space narrowing (present/absent) of both talocrural and posterior talocalcaneal joints were assessed and heel valgus angle was measured. Ankle changes (erosion plus joint narrowing) were observed in 15 patients (39.5%, 17 of 76 lower limbs), talocalcaneal changes in 18 (47.4%, 31 lower limbs) and valgus deformity of the hindfoot in 22 (57.9%, 40 lower limbs). Involvement of talocrural and talocalcaneal joints as well as alignment abnormalities were symmetrical in 13.3%, 77.8% and 81.8% of the cases, respectively. All the CT findings were significantly related to disease duration (p = 0.02) and hindfoot injuries to Ritchie index too (p < 0.05). No relationship with seropositivity was observed. Our study confirms that radiographic changes do not entirely mirror clinical evidence and shows that CT does not represent a routine examination for RA patients, but could be reserved to those with prolonged disease or severe heel deformity to plan surgery.

Adult↗
PubMed1995

Mammography with synchrotron radiation.

PURPOSE: To determine the feasibility of using synchrotron radiation (SR) in diagnostic mammography. MATERIALS AND METHODS: Monochromatic SR of x-ray beams of selected energies of 14-20 keV were used to obtain mammograms of surgically removed breast specimens that contained tumor nodules. For comparison, conventional mammograms of the same specimens were also obtained. RESULTS: The mammograms obtained with SR had higher contrast and better resolution than did traditional mammograms and demonstrated excellent detail in all cases studied. The mean glandular doses at 17 and 18 keV were 1.56 and 0.83 mGy, respectively, which is compatible with the mean value of 1.41 mGy delivered with the conventional grid apparatus. CONCLUSION: SR mammography appears to be a promising diagnostic imaging technique.

Animals↗
PubMed1992

[A multicenter study for the evaluation of the diagnostic efficiency of mammography and echography in nonpalpable breast neoplasms].

The Breast Section of the Italian Society of Radiology set up a cooperative study which included 17 Departments of Radiology and Breast Diagnosis in order to evaluate the diagnostic accuracy of US versus mammography in nonpalpable breast lesions. From January 1, 1989 to december 31, 1990, 400 nonpalpable breast lesions (142 benign lesions, 59 in situ and 199 infiltrating carcinomas) were detected by mammography and/or US; they had questionable/suspicious findings which called for further investigation by means of cytology and/or histology. US proved much less sensitive in non-palpable carcinomas than mammography (49.2% vs 93.8%), also in younger women, and failed to detect 50% of the benign/malignant nonpalpable lesions identified by mammography. US sensitivity was directly related to lesion diameter and probe frequency: 38.7% in infiltrating carcinomas < or = 5 mm vs 56.8% in those > 10 mm; 12% in the patients examined with a 5-MHz probe vs 57.7% in those examined with a > or = 7.5-MHz probe. Furthermore, the most significant US patterns of nonpalpable lesion were irregular contours, posterior attenuation and irregular internal echoes, while an irregular skin line and Cooper ligaments had no significant relation with carcinoma. Thus, breast US cannot be used as a screening test on asymptomatic patients not even on young women with radiologically dense breasts. On the contrary, US performed with high-frequency probes is useful in the assessment of nonpalpable lesions identified by mammography, and allows, in many cases, US-guided cytology and preoperative localization.

Adult↗
PubMed1992

[Quality control of stereotaxic cytologic test of non-palpable lesions of the breast].

The authors compare the accuracy and other indicators of efficiency of ten centers (1,784 total cases) performing stereotaxic cytology and adhering to a multicentric study aimed at validating a quality control system for this diagnostic procedure. The results from single centers were compared with average results. No significant differences were observed for most centers from the average sensitivity (86%), specificity (91%), positive predictive value of a dubious (57%) or positive (96%) cytologic report, inadequacy rate on malignant (6%) or benign (11%) lesions, and benign/malignant biopsy ratio (0.63). Some significant differences from the average values indicated the need for some centers to review different phases of the diagnostic process, namely to verify the accuracy of sampling sites (low sensitivity with good specificity and predictivity), to review the criteria for cytologic diagnosis (specificity less than 90%, low predictive value or higher predictive value for dubious compared with positive reports), to optimize the impact of cytology on the final decision (lack of reduction of benign/malignant biopsy ratio). Periodic check of the above parameters is proposed as a routine quality control of this diagnostic procedure.

Breast Diseases↗
PubMed1989

[Study of diet-induced thermogenesis using telethermography in normal and obese subjects].

It is well established that food ingestion induces increased thermogenesis, but the site in man of this increased heat production is still not known. Recent data suggest that brown adipose tissue or the liver may have an important role in this phenomenon. Since recent research provides some evidence to suggest that activation of thermogenesis in a specific organ or tissue may determine increased skin temperature in the surrounding region, we have studied skin temperature in the dorsal interscapular and in the liver regions using infra-red thermography in groups of normal and obese subjects before and after administration of oral glucose. In a separate group of normal subjects we studied oxygen consumption before and after glucose administration. While oral glucose produced a clear increase in thermogenesis, no ascertainable variation was observed in body temperature and, therefore, of heat dispersion in any of the regions studied in either normal or obese subjects.

Adult↗
PubMed1989

[Aseptic osteonecrosis of the femoral head in cancer patients with neuropathies caused by vincristine and vinblastine].

Aseptic osteonecrosis has been described in many and dissimilar pathologic conditions--most frequently as the aftermath of fractures or dislocations; in falciform anemia, obesity, alcoholism; in diseases requiring constant and heavy corticosteroid therapy, and also following renal transplantation. Many of these pathologies, especially alcoholism, diabetes, uremia, and collagen vascular diseases, have a common denominator: peripheral neuropathy, which is believed to be a pathogenetic factor supporting osteonecrosis. The authors analyze 3 cases of aseptic osteonecrosis of the femoral head in cancer patients treated with vincristine and/or vinblastine. Since in these subjects severe and persistent neuropathy preceded the onset of osteonecrosis, a possible relationship is postulated between the vincristine/vinblastine treatment and the onset of femoral head osteonecrosis, through the pathogenetic mechanism of peripheral neuropathy.

Adult↗
PubMed1987

Breast cancer diagnosis under the age of forty years.

The authors report on a multicentric consecutive series of 382 cases of primary breast cancer detected before the age of 40 years. Physical examination (PE) was always performed, whereas other diagnostic tests were performed in selected cases, namely mammography (M) in 334, fine needle aspiration cytology (CYT) in 188 and thermography (TH) in 123 cases. Single tests showed a high rate of false-negative/benign cases (PE, 0.23; M, 0.26; CYT, 0.37 and TH, 0.50), especially when the T1 subgroup was considered (PE, 0.34; M, 0.38; CYT, 0.42 and TH, 0.78). The poor results recorded for TH make its current diagnostic use highly questionable. The policy of extensive biopsy of all "dubious" benign lesions on PE allowed for the detection of 41 of 382 cancers and reduced the PE false-negative/benign rate to 0.12 for the total or 0.15 for T1 cancers, although about 80 unnecessary biopsies for each cancer detected were performed in this way. The association of PE to one or more tests resulted in even lower false-negative rates (0.06 for the total, 0.10 for T1 cancers). The authors criticize the aggressive policy of extensive biopsy recommendation based only on a dubious report on PE alone and stress the opportunity of the routine association of M and CYT to PE, since this combination seems to achieve a higher breast cancer detection rate even in this age group.

Adult↗