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Biomedical subjects

D Vanel

Publications and source records attributed to D Vanel.

At least 91 records · Page 5Linked to original sources
PubMed1994

Focal areas of increased opacity in ductal carcinoma in situ of the comedo type: mammographic-pathologic correlation.

PURPOSE: To determine a histopathologic explanation for focal areas of increased opacity on mammograms of ductal carcinoma in situ of the comedo type (comedocarcinoma). MATERIALS AND METHODS: From January 1991 to January 1993, mammograms from 36 patients with comedocarcinomas were reviewed. Each mammogram was screened for microcalcifications and/or any focal area of increased opacity. The presence or absence of infiltrating components was confirmed at pathologic examination, with particular emphasis placed on the search for any stromal reaction. RESULTS: The clinical examination revealed a palpable tumor in five patients (14%) and a bloody discharge from the nipple in two (5%). Isolated clusters of microcalcifications were seen at mammography in 24 patients (67%). Nine patients (25%) had clusters associated with focal areas of increased opacity; three patients (8%) had no microcalcifications. Histologic analysis demonstrated an intense, periductal, inflammatory reaction in all 12 patients with focal areas of increased opacity. CONCLUSION: Focal areas of increased opacity are not always indicative of an infiltrating component and may merely represent intense stromal reaction.

Adult↗
PubMed1994

Factor analysis of medical image sequences in MR of head and neck tumors.

PURPOSE: To evaluate factor analysis of medical image sequences (FAMIS), a means whereby physiologic contrast enhancement kinetics, called factors, and their spatial distribution, termed factor images, are estimated after acquisition of dynamic MR images. The method is intended to recognize and characterize the different tissue kinetics automatically. METHODS: This method was evaluated in a series of 22 patients with head and neck tumors. Eleven patients presented with a previously untreated lesion. Six were examined for tumor recurrence, previously treated by multiple therapies. Five patients had preoperative chemotherapy and underwent MR before and after chemotherapy. In all cases, MR images were correlated with surgical and pathologic data. MR examinations were performed on a 1.5-T unit with static sequences and dynamic sequences acquired after bolus injection of gadolinium and processed by FAMIS. RESULTS: FAMIS was able to identify three factors representing contrast-enhancement kinetics and their associated factor images. The neoplastic component was associated with the earlier factor image, F1. Fibrosis and chemotherapy and/or radiation-induced changes were associated with the two later factors, F2 and F3. The limits of this method were highly vascularized tissues whose earlier factor was similar to that of neoplastic tissues (mucosae and salivary glands), patient motion, responsible for artifacts in FAMIS, and lesions of less than 5 mm. CONCLUSION: FAMIS of dynamic MR studies was useful for differentiating neoplastic tissue from tissue having undergone changes by chemotherapy and/or radiotherapy, but it did not improve the ability of MR to characterize neoplastic tissues in previously untreated patients.

Adult↗
PubMed1993

Aggressive fibrous dysplasia of the maxillary sinus.

Fibrous dysplasia is usually a slowly progressive, benign disease that develops over several years and presents with deformity or mild symptomatology. Five of 34 patients (ages 4-21 years), who were subsequently diagnosed histologically as having fibrous dysplasia of the maxillary sinus, rapidly developed soft tissue masses of the malar region over a period of less than 4 months with accompanying pain (2 patients) and nasal obstruction and exophthalmos (2 patients). Each was clinically suspected of having a sarcoma; two had been thought to have an "osteofibrosarcoma" on initial biopsy at outside hospitals. After resection, all lesions developed regrowth. At histopathologic examination, both initial and recurrent masses proved to be typical fibrous dysplasia with spicules of woven bone in cellular, sometimes vascular, fibrous tissue. No malignant degeneration was found. On conventional radiography, aggressive fibrous dysplasia produced opacification and expansion of the maxillary sinus and apparent disruption of its wall with an associated soft tissue mass. Computed tomography (CT) demonstrated voluminous heterogeneous masses with "ground glass appearance", calcifications, areas of enhancement, low attenuation, cystic areas, and a thinned, sometimes interrupted, maxillary wall. Despite the aggressive clinical course for both initial and recurrent lesions, the CT findings of a "ground glass" mass with calcifications surrounded by a maxillary sinus wall, even if incomplete, can suggest the diagnosis of aggressive fibrous dysplasia.

Adolescent↗
PubMed1993

Bone metastases as the presenting manifestation of rhabdomyosarcoma in childhood.

Rarely, rhabdomyosarcoma can present with bone pain and bone lesions on radiographs without evidence of a primary tumor. Of 428 children with biopsy-proven rhabdomyosarcoma, four presented with radiographic evidence of bone metastases, but no primary tumor was found on subsequent evaluation. On radiographs, these metastases, located most commonly in the metaphyses of the extremities and in the spine, displayed a destructive or diffusely permeative pattern without sclerotic margins and mimicked the more common neuroblastoma. One patient also had diaphyseal cortical lytic metastases of the tibia. Radiographs defined metastases of the extremities better than the correlative bone scans. In the spine, on T2-weighted magnetic resonance (MR) images, metastases displayed high signal intensity which contrasted with the low-signal-intensity marrow in these pediatric patients. On histopathologic examination, metastatic rhabdomyosarcoma was composed of small cells of variable size, shape, and growth pattern similar to other round cell tumors. A positive desmin immunohistochemical test helped to establish the diagnosis. The radiologist, pathologist, and clinician should be aware of this unusual presentation of rhabdomyosarcoma so that suitable immunohistochemical tests are performed and appropriate chemotherapy given.

Adolescent↗
PubMed1993

Polyhedral microcalcifications at mammography: histologic correlation with calcium oxalate.

Pathologists have associated calcium oxalate dihydrate (weddellite) in breast biopsy specimens with benign or borderline lesions and rarely with malignancy. These microcalcifications may have a polyhedral shape in histologic specimens owing to their crystalline structure. A retrospective radiologic-histologic correlation study was performed on 300 clusters of microcalcifications to determine if microcalcifications with a polyhedral shape could be found at mammography. In 19 cases (6.3%), polyhedral microcalcifications (PMs) were detected by two radiologists. In 12 of these 19 cases, weddellite crystals were found in the histologic specimen under polarized light; in seven cases, no calcification was found. Although rare, PMs can be found at mammography by radiologists aware of their existence. They are due to weddellite crystals and in this series were associated with benign disease in 89% of cases. Prospective studies are required to determine the frequency of PMs on screening mammograms and to evaluate their negative predictive value.

Breast↗
PubMed1993

Extraskeletal mesenchymal chondrosarcoma.

Among seven patients with extraskeletal mesenchymal chondrosarcoma (EMC), three children (aged 3-6 years) developed EMC in a central location and four adults (aged 38-54 years) developed EMC in both central and peripheral sites. Conventional radiography and tomography and computed tomography (CT) depicted EMC as a soft-tissue mass with ring, arc, stippled, and highly opaque calcifications in four patients. Contrast-enhanced CT showed lobulation and peripheral tumoral enhancement, sometimes with central low-attenuation areas. On magnetic resonance (MR) images, EMC was a lobulated mass with high signal intensity on T2-weighted images and enhancement with low-signal-intensity focal areas on contrast-enhanced T1-weighted images. All adults developed recurrences and/or metastases and died. Of the three children, two were living and free of disease at the end of the study and the third child died of chemotherapeutic-induced leukemia. Although imaging features of EMC are nonspecific, its chondroid-type calcifications and foci of low signal intensity within enhancing lobules may reflect its dual histopathologic morphologic characteristics of differentiated cartilage islands interspersed within vascular undifferentiated mesenchyme.

Adult↗
PubMed1993

Assessment of breast cancer recurrence with contrast-enhanced subtraction MR imaging: preliminary results in 26 patients.

Local relapse was suspected in 26 women treated conservatively for breast cancer. All women underwent routine magnetic resonance (MR) imaging and a dynamic MR subtraction study after injection of gadolinium-tetraazacyclododecanetetra-acetic acid. Twelve women had no local relapse. Surgical biopsy enabled confirmation of recurrence in 14 patients. Routine MR imaging did not allow differentiation of recurrence from glandular or scar tissue. Except for one case of fat necrosis, patients without local relapse showed no contrast enhancement 1 minute 34 seconds after injection. At dynamic MR imaging, all recurrences showed contrast enhancement 1 minute 34 seconds after injection. Nodular enhancement (n = 11) was found in invasive carcinoma, whereas linear enhancement was seen in intraductal carcinoma (n = 3). Subtraction of precontrast from postcontrast images always allowed better visualization of contrast enhancement. Contrast-enhanced subtraction dynamic MR imaging may prove to be accurate in diagnosis of local relapses of breast cancer.

Adult↗
PubMed1993

Case report: clear cell adenocarcinoma of the vagina: MR features.

Clear cell adenocarcinoma (CCA) of the vagina and the cervix is a rare tumour. Since 1971 its increased incidence has been ascribed to intrauterine exposure to diethylstilboestrol (DES) and as a consequence the US Food and Drug Administration has banned the use of all DES-type medications during pregnancy. We report a case of CCA demonstrated by magnetic resonance imaging.

Adenocarcinoma↗
PubMed1992

Factor analysis of dynamic magnetic resonance imaging in predicting the response of osteosarcoma to chemotherapy.

RATIONALE AND OBJECTIVES: The response of osteosarcoma to preoperative chemotherapy was assessed using dynamic magnetic resonance imaging (MRI) processed by factor analysis of medical image sequences (FAMIS). METHODS: Forty-nine dynamic image sequences, acquired after a bolus injection of gadolinium in 10 patients, were processed by FAMIS: FAMIS is a means whereby physiologic contrast enhancement kinetics, called factors, and their spatial distribution, termed factor images, are estimated. Tumor volumes were measured on static MRIs, and factor images were compared with histologic maps of the resected specimens. RESULTS: A substantial increase in tumor volume reflected a poor response to chemotherapy. Viable tumor was precisely depicted by the early vascular factor image, reflecting rapid uptake by tumor vessels. This early uptake disappeared in all five patients who responded to chemotherapy, whereas it persisted in four of five nonresponders. CONCLUSION: FAMIS of dynamic MRI is proposed as a possible means of predicting the response of osteosarcoma to chemotherapy.

Adolescent↗
PubMed1992

Osteosarcoma: chemotherapy-induced changes at MR imaging.

Fifty-seven patients undergoing chemotherapy for osteosarcoma underwent evaluation with magnetic resonance (MR) imaging to identify changes related to a good or poor response. Spin-echo MR images obtained after preoperative chemotherapy were compared with images obtained before treatment. Histopathologic examination of each resected specimen was used to quantify the response. An increase in tumor volume and increased or unchanged edema were predictive of a poor histopathologic response (predictive values, 85%-92%). Decreased or unchanged tumor volume and a decrease in edema were poor predictors of a good response (predictive values, 56%-62%). Improved tumor demarcation, an increase in the size of areas of low signal intensity, and a decrease in joint effusion occurred independently of histopathologic response in almost half of the patients. With a subjective interpretation of MR images, poor respondents can be identified if an increase in tumor volume or no decrease in the amount of edema is seen. Subjective criteria do not contribute to the identification of good respondents.

Adolescent↗
PubMed1992

Adenoid cystic carcinoma of the head and neck: evaluation with MR imaging and clinical-pathologic correlation in 27 patients.

Twenty-seven adenoid cystic carcinomas (ACCs) of the head and neck in 27 patients were evaluated in a retrospective study based on findings at magnetic resonance (MR) imaging and pathologic and clinical examination. Clinical follow-up was obtained over a mean period of 6.3 years (range of follow-up, 3 months to 17 years); all patients underwent one to seven MR examinations. On T2-weighted images, lesions with low signal intensity corresponded to highly cellular tumors (solid subtype) with a poor prognosis; lesions with high signal intensity corresponded to less cellular tumors (cribriform or tubular subtype) with a better prognosis. MR images were not specific in differentiation of ACCs from other types of tumors; this result underscores the need for biopsy to ensure correct diagnosis. Local, intracranial, osseous, and perineural invasion was depicted, but because of its lack of specificity, MR imaging caused overdiagnosis of tumor extension, particularly perineural spread and bone abnormalities.

Adolescent↗
PubMed1992

Osteosarcoma after chemotherapy: evaluation with contrast material-enhanced subtraction MR imaging.

A new magnetic resonance (MR) technique, gadolinium-enhanced subtraction MR imaging, was developed to evaluate the response of patients with osteosarcoma to chemotherapy. Ten patients, who had received chemotherapy for osteosarcoma of the lower extremity, underwent MR imaging 3 days before surgery. After routine MR imaging was performed, subtraction MR was performed in the plane in which the tumor was best visualized. With gadopentetate dimeglumine (0.1 mmol per kilogram) on a standard MR console, subtraction images were created by subtracting precontrast images from gadolinium-enhanced T1-weighted images. The time of maximal tumoral vascular uptake was 1 1/2 minutes after injection, and, therefore, the subtracted image obtained at this time was used for evaluation of viable tumor. Independently, radiologists and histopathologists examined their respective studies for viable tumor to differentiate responders from nonresponders. Four of 10 osteosarcomas were classified as good responders because they appeared as nonenhancing masses, with or without enhancing thin lines, or small nodules (< or = 3 mm wide). At histopathologic examination, all were good responders with less than 3% viable tumor. Six of 10 osteosarcomas were classified as nonresponders because they appeared as enhancing high-signal-intensity masses measuring more than 3 mm in width. Five tumors had between 18% and 43% viable tumor cells.

Adolescent↗
PubMed1992

Imaging in the follow-up of soft tissue tumors.

Local recurrences of aggressive soft tissue tumors are frequent and very difficult to detect clinically after surgery and radiation therapy. Ultrasound is limited because the skin is thick. On contrast-enhanced CT, both scars and recurrences increase their signal. MRI is the best technique, and the only one we presently use in the detection of recurrent tumors. We are reporting 511 follow-up examinations in 182 patients after tumor removal. All patients had histologic confirmation or at least 6 months follow-up. There were 164 malignant tumors and 18 cases of aggressive fibromatosis.

Contrast Media↗