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Biomedical subjects

M Blanc

Publications and source records attributed to M Blanc.

At least 19 recordsLinked to original sources
PubMed1995

[A comparison between endoral radiography and electronic magnification of digital orthopantomography].

We compared the electronic magnifications obtained from digital panoramic radiographs with intraoral radiographs with a new high resolution film. Fifty-two patients were submitted to both examinations--76 comparative studies and 217 teeth studied in all. The two techniques appeared substantially comparable in terms of diagnostic effectiveness. The measurement of the alveolar ridge was strictly equivalent for the two examinations (< 1 mm disagreement in 80% of cases). The profile of lamina dura and the image of the radicular canal were better depicted with intraoral films. A useful advantage offered by digital images was the possibility of recognizing the soft tissues. In dental caries intraoral films was more effective than digital images and were correctly depicted small carious cavities (< 2 mm depth, 87 vs 74%). Digital panoramic radiography can be considered a promising alternative to panoramic film. Its electronic magnification may be a valuable diagnostic complement to intraoral films for the study of periodontal disease, but it cannot replace intraoral films for the assessment of fine dental details, small caries in particular. The new intraoral film was substantially equivalent to digital images for the assessment of bone lesions and of periodontal disease.

Adult↗
PubMed1995

[The spatial resolution of the digital storage phosphor system. The monitor and film compared].

The physical characteristics of radiographic images, namely spatial resolution and contrast, have obvious effects upon diagnostic image usefulness. We investigated the spatial resolution of both radiographs and magnified digital obtained with a storage phosphor system, in comparison with a film-screen combination. This study was carried out on the conventional radiographs of a phantom grid 0.5 mm thick, with resolution ranging from 0.5 to 10 lp/mm. Each examination was compared at naked eye and with the electronic evaluation of a region of interest on both standard and magnified views or by digitization with a charge coupled detector (CCD) television camera followed by the computing of the modulation transfer function curve. Our results demonstrate a higher spatial resolution of direct magnification, on both digital and film-screen pictures (over 5 lp/mm). On the contrary, the electronic magnification on the monitor yields the same spatial resolution as non-magnified digital images (up to 4.3 lp/mm). By selecting appropriate regions of interest, we could demonstrate the compression of the non-magnified images on the monitor. The modulation transfer curves show that direct magnification yields higher spatial resolution than electronic magnification and non-magnified views. Viewing electronically magnified images on the monitor yields the same resolution as contact radiographs: the monitor offers the advantage of an easier study of the regions of interest.

Evaluation Studies as Topic↗
PubMed1995

[Photo Compact Disc: proposal for the electronic storage of images].

We applied the Photo-CD technology to create an electronic image file easy and quick to use to optimize the retrieval of medical images for teaching purposes. We digitized 1,500 slides of diagnostic examinations from the archive of our Institution: the corresponding electronic files were stored on Photo-CD disks. The data relevant to every image were collected and recorded with the help of a relational data-base program. Thus, each user could retrieve the suitable images from the optical disks by a multiple and flexible key-word search. We compared the use of the electronic archive with a traditional hand-based file with the help of 3 teachers committed to prepare a lesson containing 5 slides on different subjects. The use of the electronic image archive corresponded to markedly shorter searching and file updating times. We tried also to assess the capabilites of this filing procedure for image post-processing and for the build-up of self-assessment programs.

CD-ROM↗
PubMed1995

[Computerized tomography with lipiodol in the assessment of hepatocellular carcinoma].

In this paper we report the results obtained with Lipiodol CT in 39 patients with hepatocellular carcinoma (HCC). All patients had focal or multifocal nodular HCC with FNB confirmation and were all submitted to CT 15-20 days after the injection of Lipiodol in common or proper hepatic arteries during an angiographic maneuver. Lipiodol CT showed all the lesions US had demonstrated and depicted more lesions in 12 patients (30.7%)--67 lesions in all. The lesions demonstrated by Lipiodol CT were always smaller than 2 cm: 9/12 had been missed by US, 6/12 by CT and 7/12 by arteriography. In 34/67 lesions (50.7%) enhancement was homogeneous, in 29/67 (43.2%) inhomogeneous and in 4/67 cases (5.9%) Lipiodol was not retained. Lipiodol uptake depended on lesion size: if the lesion was 1-2 cm, uptake was homogeneous, while bigger lesions exhibited inhomogeneous uptake. Lesions bigger than 4 cm exhibited no Lipiodol uptake and were necrotic. A surgical resection was performed in 21/39 patients (53.8%). To conclude, Lipiodol CT is a valuable technique in the preoperative screening of HCC, particularly in the detection of additional lesions: in our series they were demonstrated in 30.7% of patients.

Adult↗
PubMed1995

[Dosimetric evaluations in dental radiology: comparison of the digital system and the conventional system].

The dosimetric values measured on digital dental examinations (panoramic radiography and cephalography) were compared with those obtained with screen-film combinations. The X-ray dose was measured at the critical organs (lens, thyroid, cervical cord) on an anthropomorphic phantom, using thermoluminescence dosimeters and an ionization chamber: the radiographic unit was set at the same exposure values used for standard human studies in adults and children. The mean thyroid dose for screen-film panoramic radiographs was 0.037 mGy in the child and 0.053 in the adult; the lens and the cord doses were 0.009-0.012 mGy and 0.096-0.135 mGy, respectively. Digital panoramic radiography gave the thyroid a dose of 0.013 mGy in the child and 0.016 mGy in the adult: such a marked dose reduction was observed for the lens and the cervical cord too (0.0044-0.0052 mGy and 0.035-0.042 mGy, respectively). With conventional film cephalography the thyroid was given a mean dose of 0.042-0.072 mGy according to age and to patient's size; the lens received higher doses (0.420-0.720 mGy). These values were markedly reduced with the digital technique; 0.032-0.034 mGy to the thyroid gland and 0.320-0.340 mGy to the lens; spinal cord doses became negligible with digital exposures (0.009-0.010 mGy). The overall analysis of dosimetric values demonstrated a mean dose reduction averaging 40-60% with respect to standard film exposure. This difference is more apparent in the adult, since the linear dose-response pattern of the digital system allows good images to be acquired in "thicker" people without markedly increasing exposure values.

Adult↗
PubMed1994

[Radiographic enlargement in the study of hand diseases. Digital versus conventional techniques].

The electronic magnification of digital images was compared with direct digital magnification and with plain radiograph magnification. A whole-body computed radiographic system with photostimulable phosphor plates contained inside standard X-ray cassettes was used. The small bones of the hands and wrists of 18 patients with traumatic (10 cases) or degenerative (8 cases) bone conditions mainly due to chronic renal failure were studied. Each patient was examined with all three techniques: the images were retrospectively reviewed by four observers relative to resolution, contrast, visibility of the lesions and diagnostic value of each method. The statistical analysis of our results demonstrated better yield of direct digital magnification than of plain radiograph (p = 0.00043) and of electronic (p = 7.5 10(-13) magnification. This finding was mainly due to density and contrast optimization of digital images, in spite of their low spatial resolution. This feature allows good simultaneous representation of structures with different radiographic densities, as it happens in the hand and wrist. Electronic magnification yielded less brilliant results, even if compared with plain radiographic studies (p = 0.0032). However, this limitation was compensated for by the fact that this technique is easier and quicker to perform and that it does not require any additional X-ray exposure.

Adult↗
PubMed1992

Long-term outcome and sequelae in aggressive lymphoma patients treated with the LNH-80 regimen.

One hundred patients with aggressive malignant lymphoma treated with the LNH-80 regimen were evaluated for long-term survival, late relapse and long-term sequelae. The LNH-80 regimen consisted of three intensive courses of adriamycin, cyclophosphamide, vindesine and bleomycin, followed by consolidation and final intensification, as previously described. Of the eighty-four patients who achieved CR after induction, fifty-two are alive in continuous complete remission with a median follow-up of 9.2 years. Twenty-nine CR patients (35%) relapsed. Sixty-six percent of the relapses occurred during the first 18 months following the end of treatment but late relapses were observed up to 7 years off-therapy. The fifty-two long-term responders were evaluated for their ability to resume work, sexual function, fertility and presence of long-term sequelae. Of the 41 patients who worked before diagnosis of their disease, 66% had resumed their normal jobs and 24% had retired. Sexual activity was considered to be satisfactory by 66% of the patients. Eleven of the 15 patients (73%) who wanted children had between one and three children. Seven patients (14%) were considered to have mild long-term sequelae but all long-term survivors reported having an acceptable quality of life. Five of the patients who reached CR (6%) had second neoplasias. The LNH-80 regimen allowed 52% of the patients to benefit from long-term disease-free survival with minor long-term toxicity.

Adolescent↗
PubMed1992

[Prognostic factors, late relapse and outcome of patients with aggressive malignant lymphoma: long term results of LNH-80 protocol].

The 100 patients with aggressive malignant non Hodgkin lymphoma treated with the LNH-80 regimen were evaluated for long-term survival and quality of life. The LNH-80 regimen consisted of three intensive courses of adriamycin, cyclophosphamide, vindesine and bleomycin, followed by consolidation and final intensification, as previously described. Of the eighty-four patients who achieved CR after induction, fifty-two patients are alive in continuous complete remission with a median follow-up of 9.2 years. Twenty-nine CR patients (35%) relapsed. Sixty-six percent of the relapses occurred during the first 18 months following the end of treatment but late relapses were observed up to 7 years off-therapy. Factors adversely correlated with response in multivariate analysis were poor performance status, bone marrow involvement and the presence of more than one extranodal site. Factors adversely correlated with survival were age, high grade subtypes, and bone marrow involvement. The fifty-two long-term responders were evaluated for quality of life parameters such as working ability, sexual function, fertility and absence of long-term sequelae. Of the 41 patients who worked before disease, 66% had resumed their normal job and 24% had retired. Sexual activity was considered to be satisfactory by 66% of the patients. Eleven of the 15 patients (73%) who wanted children had between one and three children. Seven patients (14%) considered having mild long-term sequelae but all long-term survivors reported having an acceptable quality of life. Five of the patients who reached CR (6%) had a second neoplasia. The LNH-80 regimen allowed 52% of the patients to benefit from long-term disease-free survival with minor long-term toxicity.

Adolescent↗
PubMed1992

[The use of digital techniques with storage phosphors for orthopantomography. Preliminary note].

Digital panoramic tomographies with light-emitting phosphors were obtained in 39 patients, during a study on the clinical applications of digital imaging. Performing digital panoramic radiographies required the preliminary adaptation of the imaging plates to the cassette holder of the radiographic equipment. The digital images were post-processed according to two different protocols, both of which were recorded for each patient. The former image was quite similar to standard X-ray films and was called "analogic-like". The latter, called "xeroradiographic-like", featured a flattening of the overall contrast together with detail contrast enhancement due to the presence of an edge effect, as it occurs in xeroradiography. Digital panoramic tomography allows a marked reduction in patient's exposure to X-rays. In addition, this technique offers constant high-quality results, due to the possibility of recovering over- or under-exposed images during post-processing. Xeroradiographic-like digital films may reduce the sharp contrast that is often present between the anterior and the lateral portions of the maxillary and mandibular arches, thus improving the diagnostic reliability of the examination. Other modalities of digital post-processing may be helpful to depict gingival soft tissues, with obvious advantages for the study of periodontal diseases.

Adolescent↗
PubMed1991

Skin ultrasound in dermatologic surgical planning.

High-resolution ultrasonography was performed on 55 patients with palpable skin lesions, all submitted to surgical excision and to histologic diagnosis. In all the cases, the ultrasound picture was confirmed by the surgical appearance of the lesions. The sonographic structure was characteristic in the case of cysts and angiomas, lymphangiomas in particular. Ultrasonography is considered a simple and reliable technique for the pre-operative evaluation of skin nodules, as it gives a clear picture of their size, depth, and outline. However, sonography cannot substitute for the clinical dermatologic approach and the need for an histologic diagnosis.

Adult↗
PubMed1991

Bronchial carcinoid tumors: radiologic observations in 49 cases.

A retrospective evaluation was performed of radiographs obtained in 49 cases of bronchial carcinoid at presentation and during a follow-up period of 12 years. Histologic diagnosis from the surgical specimen was available in all cases. Carcinoids appeared most frequently (77%) as round or oval opacities with sharp and often notched margins. They often induced airway compression with pulmonary atelectasis; enlarged hilar lymph nodes from metastasis were rare. Recurrence after surgical removal was not frequent; the recurrent masses had the same radiographic features as the original tumor. The diagnosis of bronchial carcinoid must be taken into consideration when a slowly growing radiopaque mass with well-defined margins is discovered on chest films. The radiologist must remember that these tumors can be resected with a fairly good prognosis even when they are large.

Bronchial Neoplasms↗
PubMed1990

Ultrasonography of nodular and infiltrative lesions of the skin and subcutaneous tissues.

Ultrasonography with high-frequency probes was performed on 80 dermatological patients carrying palpable lesions of the skin. The case list included hemo- and lymphangiomas (16 cases), cysts (13 cases), Kaposi sarcomas (9 cases), and panniculitis (20 cases). All lesions underwent open biopsy and histological examination. Ultrasound yielded technically adequate images in 74/80 cases (93%). Angiomas appeared as multiple transonic cavities separated by hyperechoic septa; cysts were usually echo free or weakly echogenic, with smooth outlines. Kaposi sarcomas corresponded to superficial hypoechoic nodules with blurred margins, while panniculitis appeared as a diffuse thickening of the subcutaneous space. When acute inflammation was present, as in most cases of erythema nodosum, a nonhomogeneous hypoechoic pattern was found.

Cysts↗