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Biomedical subjects

D Vanel

Publications and source records attributed to D Vanel.

At least 19 recordsLinked to original sources
PubMed1998

Electropotential measurements as a new diagnostic modality for breast cancer.

BACKGROUND: Proliferative changes in breast epithelium are an intrinsic aspect in the development of breast cancer, and result in regions of epithelial electrical depolarisation within the breast parenchyma, which can extend to the skin surface. Diagnostic information might be obtained from a non-imaging and non-invasive test based on skin-surface electropotentials. METHODS: In 661 women, scheduled for open biopsy at eight European centres, we studied whether measurements of breast electrical activity with surface sensors could distinguish benign from malignant breast disease. A depolarisation index was developed. RESULTS: We found a highly significant trend of progressive electrical changes according to the proliferative characteristics of the biopsied tissue. Discriminatory information was obtained in both premenopausal and postmenopausal women, and the index was not related to age. The best test performances were for women with palpable lesions. The median index was 0.398 for non-proliferative benign lesions, 0.531 for proliferative benign lesions, and 0.644 for cancer (ductal carcinoma-in-situ and invasive). A specificity of 55% was obtained at 90% sensitivity for women with palpable lesions when a discriminant based on age and the depolarisation index was used. INTERPRETATION: This new modality may have diagnostic value, especially in reducing the number of unnecessary diagnostic tests among women with inconclusive findings on physical examination. Understanding and control of the biological variability of these electrical phenomena will be important in the improvement of this test. Studies in populations with a lower cancer prevalence are needed to assess further the diagnostic value of this approach.

Adolescent↗
PubMed1998

Dynamic contrast-enhanced MRI with subtraction of aggressive soft tissue tumors after resection.

OBJECTIVE: To report the application of dynamic contrast-enhanced subtraction MRI for detecting recurrences in aggressive or malignant soft tissue tumors. DESIGN: The imaging studies consisted of static (T1- and T2-weighted spin-echo) acquisitions, followed by dynamic conventional spin-echo short TR/TE images (at 45 s, 1 min 30 s and 5 min) after a bolus of intravenous contrast medium. Contrast images were subtracted from the precontrast scan on the console. PATIENTS: Ninety-eight patients were studied who had had aggressive or malignant soft tissue tumors treated by surgery, and were followed up to assess recurrences. RESULTS: Subtraction MRI characterized recurrences better than routine sequences in 10 patients (1 lesion was seen only with this technique, 6 were better delineated, and 3 inflammatory pseudotumors were identified), and less well in 4 cases. CONCLUSION: As the number of levels studied on dynamic images is limited, and all but one recurrence were detected on T2-weighted images, it remains logical to start the examination with T2-weighted spin-echo images, and to use the dynamic study only if contrast injection is required.

Adult↗
PubMed1998

A recurrent left atrium leiomyosarcoma.

Cardiac leiomyosarcoma is a rare tumour which can grow either intramurally or extramurally. Its prognosis is dismal. Surgery lengthens survival, but recurrences usually occur in the short term. Gated MRI is useful for the assessment of cardiac masses since it provides fine spatial and contrast resolution. We present the case of a left atrial leiomyosarcoma whose recurrence was diagnosed by gated MRI. Our patient underwent a second resection but died soon after.

Echocardiography, Transesophageal↗
PubMed1998

Follow-up of musculoskeletal tumors. I. Local recurrence.

The prognosis for a patient with a musculoskeletal sarcoma has improved considerably over the past two decades largely due to the use of adjuvant chemotherapy. Surgical techniques have become more sophisticated with limb salvage, the preferred management in the majority of cases. Imaging plays an important role in the assessment of suspected local recurrence of tumor. This pictorial essay reviews the different imaging options and highlights various pitfalls in the detection and diagnosis of recurrence. The role of magnetic resonance imaging in this respect is stressed.

Adolescent↗
PubMed1998

MRI of bone metastases.

Some knowledge of MR theory is required to be able to achieve high contrast between bone metastases and normal marrow. Three factors are used in MR to diagnose bone metastases; fat-water distribution, artifacts induced by bone trabeculae, and uptake of contrast medium. Using MR-histological correlations based on specimens of the lumbar spine, and studies of patients, we explain the advantages and limitations of sequences studying fat and water (spin-echo T1, STIR, in- and out-of-phase gradient echo, fat presaturation), bone trabeculae (gradient echo with long TE), and the injection of contrast medium.

Adipose Tissue↗
PubMed1998

Lymph node metastases: safety and effectiveness of MR imaging with ultrasmall superparamagnetic iron oxide particles--initial clinical experience.

PURPOSE: To evaluate the clinical and biologic safety of ultrasmall superparamagnetic iron oxide particles (AMI-227) as a contrast agent for magnetic resonance (MR) lymphography and to assess their efficacy for the differentiation of metastatic and benign nodes in patients with urologic and pelvic cancer. MATERIALS AND METHODS: Thirty adults suspected of having lymph node metastases underwent MR imaging before and 22-26 hours after intravenous infusion of AMI-227 (1.7 mg Fe/kg). Sixty histopathologically proved lymph nodes were analyzed on MR images, and 29 of these nodes were also analyzed quantitatively. RESULTS: AMI-227 was well tolerated with no major side effects. It allowed the detection of 10 additional nodes relative to those detected at MR imaging without AMI-227. None of the 27 metastatic nodes showed a decrease in signal intensity (SI) on AMI-227-enhanced images; nine of 27 metastatic nodes showed an increase in SI on T1-weighted images, probably resulting from altered capillary permeability in the tumor. A visually perceptible reduction in SI, indicating active AMI-227 uptake, was observed on postcontrast T2- and T2*-weighted images in 16 of 21 benign nodes. The SI ratio of benign nodes was lower than that of metastatic nodes on T2- and T2*-weighted images. The sensitivity of AMI-227-enhanced MR lymphography was 100%, and the specificity was 80%. CONCLUSION: AMI-227 is safe and may facilitate the differentiation of metastatic and benign nodes in patients with urologic and pelvic cancers.

Adult↗
PubMed1997

Nasopharyngeal teratoma: CT and MR findings.

Teratomas of the nasopharynx occur usually in neonates. We present a case of teratoma which was discovered in an adult, and which relapsed after 34 years. The conventional radiograms, CT, MR, and histologic appearances are described.

Adult↗
PubMed1997

Late presentation of solitary contralateral adrenal metastasis of renal cell carcinoma.

We report a case of renal cell carcinoma with solitary metachronous contralateral adrenal metastasis occurring 23 years after radical nephrectomy. The patient was treated with adrenalectomy. He is alive with no evidence of disease 1 year postoperatively. Solitary metachronous contralateral adrenal metastases from renal cell carcinoma are rare clinical conditions that may occur very late. Metastasectomy is advocated and is probably beneficial for limited metastatic renal cell cancer.

Adenocarcinoma↗
PubMed1997

Electropotential evaluation as a new technique for diagnosing breast lesions.

A new approach, termed the Biofield test, may have the potential to augment the process of diagnosing breast cancer. This technique is based on the analysis of skin surface electrical potentials measured by an array of specially designed sensors which are placed on the breasts. Measurements are recorded noninvasively and then analyzed using pattern recognition algorithms to produce an immediate and objective assessment of breast tissue in vivo. Initial clinical trials suggests that the test can achieve a sensitivity of approximately 90% and a specificity of 40-50%, which indicates that the test might be useful for excluding cancer when it is, in fact, absent. Although research to date has focused on the differential diagnosis of suspicious breast lesions, future applications could include breast cancer screening, close surveillance and diagnosis of recurrent cancers in breasts previously treated with conservative therapy, and monitoring the effectiveness of breast cancer therapies. Improvements and new applications are expected to occur as additional research and validation in actual clinical settings is performed.

Algorithms↗
PubMed1997

Mammographic patterns of inflammatory breast carcinoma: a retrospective study of 92 cases.

OBJECTIVE: To quantitate initial mammographic signs and to describe post-therapeutic patterns of inflammatory breast cancer. MATERIAL AND METHODS: Two radiologists retrospectively analyzed the initial clinical and mammographic findings of 92 patients with inflammatory breast carcinoma. The post-therapeutic mammogram (n = 75) was considered abnormal when focal opacity and or malignant-type microcalcifications were still visible. RESULTS: Redness of the skin, "peau d'orange' and increased temperature were the most common findings. A palpable mass was noted in 97% with axillary lymph node involvement in 83% of cases. All initial mammograms were abnormal. Isolated inflammatory signs were observed in 14% and malignant signs in 86% of patients (opacity = 77% and/or malignant-type microcalcifications = 47%). Skin thickening was seen in 93.5%, nipple inversion in 56.5%, increased breast density in 93.5%, stromal coarsening in 85% and hypervascularisation in 32.5% of mammograms. On post-therapeutic mammograms, 35 patients (46.5%) were suspected of having residual disease. During follow-up, 19 patients (25.3%) relapsed locally: 75% had abnormal post-therapeutic mammograms. CONCLUSION: The presence of isolated inflammatory signs on the mammogram is sufficient to suspect inflammatory breast carcinoma and biopsy must be performed in doubtful cases. Radical surgery is indicated when persistent malignant signs are still visible on mammogram after conservative treatment.

Adenocarcinoma↗
PubMed1997

Differentiation between recurrent tumor and benign conditions after treatment of gynecologic pelvic carcinoma: value of dynamic contrast-enhanced subtraction MR imaging.

PURPOSE: To compare dynamic contrast material-enhanced subtraction and T2-weighted spin-echo (SE) magnetic resonance (MR) imaging in the differentiation of fibrosis from tumor recurrence during the follow-up of treated gynecologic pelvic malignancy. MATERIALS AND METHODS: Thirty-four patients (aged 24-82 years) with 18 benign and 35 malignant lesions confirmed by means of surgery (n = 18), biopsy (n = 25), or 18-month follow-up examination (n = 10) underwent dynamic contrast-enhanced subtraction and T2-weighted SE MR imaging. Contrast material enhancement of an abnormal pelvic structure within the first 90 seconds on dynamic contrast-enhanced subtraction images or high signal intensity on T2-weighted SE images was considered indicative of malignancy. RESULTS: The sensitivity, specificity, accuracy, and positive and negative predictive values were 91%, 67%, 83%, 86%, and 86%, respectively, for dynamic contrast-enhanced subtraction imaging and 91%, 22%, 68%, 70%, and 57%, respectively, for T2-weighted SE imaging. More lesions were correctly classified with dynamic contrast-enhanced subtraction imaging than with T2-weighted SE imaging (P < .01). CONCLUSION: Dynamic contrast-enhanced subtraction imaging is more accurate than T2-weighted SE imaging for differentiating fibrosis from tumor recurrence during the follow-up of treated gynecologic pelvic malignancy. However, use of both sequences is recommended.

Adult↗
PubMed1997

Magnetic resonance imaging of the bone marrow in lymphomas and leukemias.

This article reviews MRI techniques and results in the assessment of bone marrow in patients with lymphoma. MRI is more sensitive than blind biopsy (BB) in detecting bone marrow invasion. False-negative results have been reported in low-grade non Hodgkin's lymphoma (NHL) and chronic lymphocytic leukemia. Bone marrow imaging is particularly indicated in patients with Hodgkin's disease, high grade NHL or myelocytic leukemia, with a negative BB and abnormal clinical (stage B, bone pains) or biochemical data (elevated alkaline phosphatase) and who have relapsed. During treatment. MR imaging is a valuable tool for the evaluation of response and the diagnosis of benign bone marrow complications. Knowledge of post-therapeutic patterns is essential to avoid misinterpretations. The main drawback with this technique is its inability to differentiate residual lesions from fibrosis and needle guided-biopsy is mandatory if treatment decision-making relies on the MR result, alone.

Adolescent↗
PubMed1997

Primary tumors of the musculoskeletal system.

The excellent soft-tissue contrast and multiplanar imaging capabilities of MR imaging have led to its emergence as the most significant advance in the imaging of musculoskeletal tumors. MR imaging is the modality of choice for local staging, evaluating response to preoperative chemotherapy, and long-term follow-up in bone tumors. MR imaging is the most effective modality for both primary staging of soft-tissue malignancy and detecting recurrences. This article reviews the role of conventional spin echo techniques versus newer techniques, and then discusses the indications in the diagnosis, staging, evaluation of preoperative chemotherapy, and detection of recurrences in bone and soft-tissue tumors.

Bone Neoplasms↗
PubMed1997

[Diagnosis of infraclinical lesions of the breast with dynamic MRI: results of a prospective and multicenter study].

AIM: To determine the accuracy of dynamic contrast-enhanced subfraction MRI to diagnose nonpalpable breast lesions in a prospective multicenter study. MATERIAL AND METHODS: From June to November 1994, 72 patients had a surgical biopsy for a nonpalpable breast lesion and a preoperative dynamic MR after an informed consent was obtained. MR examinations were performed on 0.5, 1 and 1.5T MR unit. Each center underwent dynamic sequences either in spin or gradient echo in T1 weighted images obtained in less than two minutes before and after injection of Gadolinium-DOTA. The presence/absence of contrast enhancement within two minutes after injection of Gadolinium were considered as positive/negative findings respectively. RESULTS: These 72 women had mammographic (n = 80) or ultrasonographic lesions (n = 2). Mammograms showed mass (n = 23), asymmetrical density (n = 2), architectural distorsion (n = 8), clustered microcalcifications (n = 47) or was normal (n = 2). Dynamic Breast MR imaging showed early contrast enhancement in 44 malignant lesions (sensitivity: 89.8%) and 13 benign lesions (specificity: 60.6%). Five intraductal carcinoma of comedo (n = 1) or non-comedo (n = 4) type did not demonstrate any early contrast enhancement. CONCLUSION: This prospective mulcentric study confirms the high sensitivity of dynamic breast MRI whatever the type of MR unit or sequences.

Adult↗
PubMed1996

CT and MR imaging of squamous cell carcinoma of the tongue and floor of the mouth.

Because contemporary treatment of oral cavity cancer involves procedures that spare the tongue and mandible, an adequate assessment of the oral cavity is essential for appropriate surgical and radiation therapy planning. Computed tomography (CT) and magnetic resonance (MR) imaging, which allow differentiation between soft tissues, are valuable tools for assessing this complex region. Their main advantage resides in their capacity to show at best the normal anatomy and the exact extent of a low-lying tumor. For display of soft tissues and tumor, MR imaging, being a multiplanar and multicontrast technique, is superior to CT. Nonenhanced T1-weighted MR imaging is better for defining the exact extent of medullary bone invasion, which appears as a low-signal-intensity area within hyperintense medullary fat. CT is optimal in detection of cortical bone invasion, which appears as an interruption or erosion of the peripheral hyperattenuating rim. Thus, in cancer of the tongue, MR imaging should be performed first. If tumor extension to the mandible is suspected (due to clinical or MR imaging findings), CT should be added. In cancer of the floor of the mouth, both MR imaging and CT should be performed in the initial work-up, especially in those cases in which there is a clinical doubt about mandibular extension of disease. The main drawback of both modalities is their lack of specificity; other methods are needed to discriminate between tumors and inflammatory or infectious diseases, particularly in the mandible. However, once the diagnosis has been confirmed histologically, treatment can be chosen based on complementary information obtained from CT and MR imaging.

Carcinoma, Squamous Cell↗
PubMed1996

MR imaging during intracavitary brachytherapy of vaginal and cervical cancer: preliminary results.

Intracavitary brachytherapy is an effective treatment for gynecologic cancers. Twelve magnetic resonance (MR) imaging studies were performed during intracavitary brachytherapy (10 initial studies and two during repeat brachytherapy) in 10 patients with clear cell adenocarcinoma (n = 9) or epithelioma (n = 1). Fifty percent of the vaginal lesions did not demonstrate high signal intensity on T2-weighted images. Individually tailored molded applicators allowed easy detection of abnormal vaginal parietal thickening on T1-weighted images: Results in seven cases were concordant with results of clinical examination, and there were no false-negative results. MR imaging was useful in controlling the relationships between the tumor and the applicator and facilitated treatment planning, since the radiation dose to the tumor volume and adjacent critical organs could be calculated accurately. Limitations of MR imaging were underestimation of superficial vaginal tumors and the inability to differentiate between tumor and inflammation after recent surgery or repeat intracavitary brachytherapy. MR imaging during intracavitary brachytherapy appears to be a useful adjunct to clinical examination.

Adenocarcinoma, Clear Cell↗