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Biomedical subjects

D Couanet

Publications and source records attributed to D Couanet.

At least 55 records · Page 3Linked to original sources
PubMed1989

[Secondary metastatic neuromeningeal localization of neuroblastoma in children].

In order to evaluate the frequency, clinical and radiological aspects and prognosis of central nervous system metastases in children's neuroblastoma, the 258 children presenting with neuroblastoma, and registered from January 1982 to August 1987, were studied. Among them, 7 patients (2.7%), of which 6 had an initially metastatic neuroblastoma, presented with a secondary neuro-meningeal involvement. Parenchyma involvement (4 cases) occurred after a mean period of time of 21 months and marked the relapses. The disease recurs later on, even when locally controlled by surgical excision and local irradiation. Meningeal involvements (3 cases) occurred after a mean delay of 12.7 months, in patients with full tumoral evolutivity, and were responsible for rapid death. The clinical presentation of these metastases differs from that in adults by the rapidity of setting up of the signs and the frequency of intracranial hypertension. CT scan allows approaching diagnosis in the majority of the cases. These data are compared with those in the literature, where 30 cases were reported: they show a high patients' average age and the worse prognosis.

Brain Neoplasms↗
PubMed1988

The role of magnetic resonance imaging in the evaluation of Ewing sarcoma. A report of 27 cases.

The experience with magnetic resonance imaging (MRI) in 27 patients with Ewing sarcoma is reported and compared with computed tomography (CT) and plain films. Plain radiography proved to be the best imaging method to asses probable histological diagnosis in all cases (n = 6). For the evaluation of chemotherapeutic response (n = 4), CT and MRI gave the same information about the variation in size of the tumor. In this small series, the high signal in T2 weighted images was not altered significantly by therapy. In preoperative evaluation (n = 14), MRI gave better information than CT of soft tissue involvement and extension within the bone marrow in two cases each. The ability of MRI to accurately define extension through the epiphyseal plate in two cases permitted limb salvage which otherwise would not have been possible. In the long-term follow-up (n = 12), three patients without recurrence one year after therapy showed a low signal in the surgical area in T2 weighted images. Nine patients had a high signal in T2 weighted images: four were reactive lesions, two had obvious recurrence, and one was a hematoma. In the two remaining cases plain films and CT were normal, in the presence of both active tumor and reactive lesions. It was not possible with MRI to differentiate active tumor from reactive change, even after Gd-DTPA infusion.

Adolescent↗
PubMed1988

[Magnetic resonance imaging for bone marrow metastases of neuroblastoma].

From March 1985 to February 1987, 41 patients (pts) presenting with a neuroblastoma underwent 52 MRI to detect bone marrow metastases. Mean age was 4 years (R: 6 m, 13 y). Acquisitions were done with a 1.5 t unit. Images were obtained in coronal (legs and pelvis) and sagittal (dorso-lumbar spine) sections. Nine out of 52 examinations were excluded because of artifacts or technical failure. In 13 cases, MRI was performed for initial staging, in 30 during follow-up. Out of 24 anatomically proven medullary involvement (18 pts), MRI showed focal abnormal signals in 23 (17 pts): foci of hypersignal in T2 weighted images, compared to the normal value of bone marrow and fat tissue, were more often detected in lower limbs than dorso-lumbar vertebral body or iliac bone. In our series, the sensitivity of MRI to detect BM metastases is 84% and the specificity is 88%. In comparison to the medullograms and bone marrow biopsy, MRI explores distinct sites, especially lower limbs which are often involved.

Bone Marrow↗
PubMed1988

Bone marrow metastases in children's neuroblastoma studied by magnetic resonance imaging.

Forty-one patients (pts) presenting with a neuroblastoma underwent 52 MRI to detect bone marrow metastases. Mean age was 4 years. Acquisitions were done with a 1.5 tesla unit. T1 and T2 weighted images were obtained in coronal (legs and pelvis) and sagittal (dorso-lumbar spine) sections. In 13 cases MRI was performed for initial staging, in 30 during the follow-up. 43/52 examinations were evaluable. Out of 24 anatomically proven medullary involvement (19 pts), MRI showed focal abnormal signals in 23 (18 pts): foci hypersignal in T2 weighted images and hyposignal in T1 weighted images compared to the normal bone marrow (BM) and fat tissue. The lesions were more often detected in lower limbs than dorso-lumbar vertebral body or iliac bone. Nineteen examinations were performed in 15 pts with cytologically and histologically normal BM. MRI raised suspicion of BM metastases in 5 pts (7 MRI). Out of those 5 pts, 1 (2 MRI) had BM relapse 9 months later; 1 (2 MRI) had intra cranial relapse 6 months later; 1 (1 MRI) is disease free 1 1/2 year later; the follow-up is too short for 2 remaining pts (2 MRI). MRI's specificity was 88.9% and sensitivity 84.4%.

Adolescent↗
PubMed1987

Ultrasonography and computed tomography for diagnosis and follow-up of biliary duct rhabdomyosarcomas in children.

The authors report eight cases of biliary duct rhabdomyosarcoma in children, examined by US and CT. There were five boys and three girls, aged 2 to 17 years. At presentation, US demonstrates the tumor mass within the liver or the hepatic hilum; it allows measurement of it and defines the relationship with portal vessels, biliary tract and other important structures. CT complements the US evaluation and determines operability. As US and CT cannot assess the histological origin of the tumor, a biopsy is mandatory before treatment. If complete surgical excision does not seem possible, percutaneous biopsy is preferable to incomplete excision and its possible complications. During the follow-up period, US can be repeated to measure tumor regression under chemotherapy. After surgery, CT seems preferable because of gas interposition. Both US and CT proved to be valuable for the early detection of local recurrence. The prognosis of these tumors remains bad. However, with more aggressive and hopefully more efficient chemotherapy a precise evaluation of the tumor extension by US and CT is very important. Surgery will then be performed only on localized tumors or on residual masses after chemotherapy.

Adolescent↗
PubMed1987

Ultrasonography and computed tomography for diagnosis and follow-up of pelvic rhabdomyosarcomas in children.

The authors report 18 cases of pelvic rhabdomyosarcomas in children examined at presentation and followed on US and CT. There were 11 boys, 7 girls; tumor location was bladder, prostate or uterus in 12, perineum in 4, buttock in 2. US is good to define tumoral extension within the bladder CT is better to delineate the extension outside the bladder and regional spread to iliac nodes. CT is the only useful examination for perineal tumors. During chemotherapy US can be frequently repeated to appreciate tumoral regression and to give measurement of the mass. Preoperative CT should be performed when tumoral regression seems sufficient to permit complete tumoral excision without pelvic exenteration. Correlation between US and CT and surgical findings proved to be good. US and CT are also very useful in the follow-up when the child has finished treatment as it can demonstrate a local recurrence before clinical symptoms appear. However, post-surgical and post-radiation changes may be difficult to recognize. These aspects are discussed.

Adolescent↗
PubMed1987

Musculoskeletal tumors: follow-up with MR imaging after treatment with surgery and radiation therapy.

Magnetic resonance (MR) imaging was used as a follow-up technique in 60 patients who underwent surgery and/or radiation therapy for primary malignant musculoskeletal tumors. MR imaging was performed on a 1.5-T imager with T1- and T2-weighted imaging sequences; MR imaging findings were confirmed by means of posttreatment surgery and histologic analysis or follow-up for at least 1 year. If a low-signal-intensity lesion was seen on T2-weighted images in a patient who had undergone radiation therapy or surgery, the patient usually did not have active tumor (sensitivity, 96%). If a high-signal-intensity lesion was seen after a patient had undergone only surgery, the patient had active tumor (six of six such cases). In patients who had undergone only radiation therapy, however, the presence of a high-signal-intensity lesion may indicate either active tumor or radiation-induced inflammatory changes. Thus, in such cases, differential diagnosis of active tumor may be difficult, if not impossible, to make from MR images.

Bone Neoplasms↗
PubMed1985

Chest computed tomography (CT) in patients with micronodular lung metastases of differentiated thyroid carcinoma.

Forty thoracic CT scans have been performed on 27 patients with micronodular lung metastases of differentiated thyroid carcinoma. Lung nodules were visualized in 14 out of 19 patients (78%) with functioning lung metastases, although their chest X rays were normal. However, only a small number of peripheral micronodules can be visualized by CT scan since the central micronodules remain undistinguishable from adjacent vessel structures. A close relationship has been found between the number of micronodules and the thyroglobulin (Tg) serum level. In patients previously treated by 131I for proven lung metastases and who had no uptake for several years, but in whom Tg remained detectable in the serum, CT scans have shown micronodules in 7 of the 13 patients with normal chest X rays. The present data suggest that these nodules are mainly a result of fibrosis. CT scanning appears to be an important complementary tool with regard to 131I whole body scintigraphies in the radiologic diagnosis of lung nodules and in the assessment of radioiodine therapy.

Adolescent↗
PubMed1984

Computed tomography after partial hepatectomy.

Twenty-two patients with surgically resectable malignant primary liver neoplasm or hepatic metastases were examined by computed tomography both before and after surgery. The anatomic modifications created by the surgery, including right lobectomy, left lobectomy, segmentectomy, and wedge resections were evaluated. Computed tomography depicted changes in the liver contour, usually after right or left lobectomy as well as secondary effects of these changes in the adjacent organs. With knowledge of these postsurgical modifications, the reparative ability of the liver can be appreciated.

Hepatectomy↗
PubMed1984

Pulmonary evaluation of patients with osteosarcoma: roles of standard radiography, tomography, CT, scintigraphy, and tomoscintigraphy.

Sixty-one radiologic evaluations were performed on 32 patients with possible pulmonary metastases from osteosarcoma. CT scanning was performed 61 times; standard chest radiography, 58; tomography, 36; scintigraphy, 40; and tomoscintigraphy, 33. Using CT as a reference (positive or negative results only), the sensitivities of the other examinations were 57% (32% of total metastases) for standard radiography, 88% (48%) for tomography, 21% (5%) for scintigraphy, and 41% (8%) for tomoscintigraphy. Of the 193 metastases, 98 were subpleural and 95 were parenchymatous. Five patients had surgery and the others had follow-up. One false-positive CT scan was thus detected. The authors' current evaluation of patients with metastases from osteosarcoma includes chest radiography and CT; the other three examinations are performed only before surgery.

Adolescent↗