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Biomedical subjects

M Laval-Jeantet

Publications and source records attributed to M Laval-Jeantet.

At least 19 recordsLinked to original sources
PubMed1995

Magnetic resonance imaging in patients with penile carcinoma.

The aim of the study was to determine the role of pre-operative magnetic resonance imaging (MRI), with and without contrast enhancement, in patients with penile carcinoma. Nine patients with a penile cancer were studied. The staging of the tumours was performed by clinical examination, MRI and surgery, according to the TNM classification. Six patients had primary tumours, of clinical stage T1 (n = 1) and T2 (n = 5). Three other patients had been previously treated and presented with a local recurrence of clinical stage T2. Surface-coil MRI was performed at 0.5 T with T1 weighted sequences before and after gadolinium-DOTA, and T2 weighted sequences. MRI results were compared with the clinical and surgical findings. T1 weighted sequences did not clearly demonstrate the margins of the tumours. T2 weighted sequences were the more useful in five patients, whereas contrast enhanced T1 weighted sequences allowed better delineation of the lesions in only three patients. Therefore, an imaging protocol should include spin echo T2 weighted sequences. Clinical examination correctly staged six of nine tumours; MRI, seven of nine tumours and the combination of both examinations, eight of nine tumours. MRI provided good evaluation of tumoral invasion into the penile shaft.

Adult↗
PubMed1992

CT image analysis of the vertebral trabecular network in vivo.

A method of computed tomography (CT) image analysis of lumbar vertebrae has been developed, providing a visualization of the trabecular network as it is represented in a 1.5 mm-thick CT image. We measured the length of the network and the number of discontinuities found in the image. The ratio of these measurements was called the "trabecular fragmentation index" (TFI). CT images from 71 women between the ages of 50 and 59, and 94 women between the ages of 60 and 69 were divided into three groups according to quantitative computed tomography (QCT) vertebral density and to the presence or absence of crushing and fractures. The measure of the network length versus the vertebral area was significantly higher in normal subjects than in osteoporotics. A TFI threshold at 0.195 could separate the normal subjects, regardless of the decade, from osteoporotic ones. In females between 50 and 69 years of age, TFI was 0.166 (SD = 0.031) for the normal group and 0.248 (SD = 0.082) for osteoporotics. The osteopenic group without fractures but low bone mineral density (BMD) showed an intermediate TFI of 0.195 (SD = 0.05), placing this population on both sides of the threshold. Correlation between TFI and BMD was only -0.60. TFI could provide new information in vivo about the state of trabecular structure, particularly in the osteopenic group.

Aged↗
PubMed1992

MR imaging of breast hemangioma in female infants.

Breast hemangioma in female infants is a rare benign lesion, prone to spontaneous regression. But when the lesion regresses there is a risk of breast atrophy if the breast bud is included in or very close to the hemangioma. A trial of corticosteroid therapy could be proposed to prevent this risk, but one must be sure that the breast bud is included in or very close to the hemangioma before treatment. We studied 4 children with breast hemangioma to evaluate the ability of MR Imaging in the diagnosis of breast bud inclusion. 0.5 Tesla axial Spin Echo T2-weighted images (TR = 2000 ms; TE = 120 ms) clearly depicted interface between high signal appearance of hemangioma and hypo-intensity of the breast bud: in our four patients we were able to determine whether or not the hemangioma involved the breast bud. Our preliminary study seems to demonstrate that MR imaging is a valuable imaging technique to determine which patients could be eligible for a trial of corticosteroid therapy.

Breast Neoplasms↗
PubMed1992

Bone densitometry in patients with multiple myeloma.

PURPOSE, PATIENTS, AND METHODS: We performed dual-energy x-ray absorptiometry in 10 selected patients with aggressive multiple myeloma in whom substantial tumor mass reduction was achieved after high-dose chemoradiotherapy followed by autologous blood stem cell transplantation. RESULTS: In most cases, bone mineral density (BMD) of the spine was initially low (Mean Z score: -2.69, SEM 0.76) and dramatically increased after treatment (mean increase 16.4%; 7.7% with 95% confidence interval 2.2 to 12.2, excluding one patient whose spine BMD increased by 94.8%). In contrast, skeletal roentgenograms, computed tomographic scans, and magnetic resonance imaging did not reveal any significant improvement of patients' bone lesions. CONCLUSIONS: In patients with multiple myeloma, bone densitometry could be a useful way to assess the efficacy of treatment on bone status.

Absorptiometry, Photon↗
PubMed1990

[Detection of cancer of the prostate. A study of 600 cases].

A free screening consultation for carcinoma of the prostate was proposed to men over the age of 50 years working in different companies in the areas of Paris. This consultation included a digital rectal examination, a blood test for determination of serum acid phosphatase and prostatic specific antigen, and two dimensional trans-rectal ultrasonography of the prostate. 600 patients were seen. 575 were evaluable. Prostate biopsy was recommended in 152 men. Ninety-three prostate biopsies were performed. Eighteen prostatic cancers and 1 urothelial cancer invading the prostate were detected with an overall incidence of prostate cancer of 3.1%. Radical prostatectomies were performed in 10 of the 18 patients with a prostate cancer. Sensitivity of digital rectal examination ultrasonography and PSA were respectively 42.8%, 47.3% and 68.4% with an abnormal serum PSA level defined as being greater than 5 ng/ml. The predictive value of a positive ultrasonography (18.7%) contrasts with the predictive value of a positive digital rectal examination (30.7%) and serum PSA (30%). Digital rectal examination and determination of serum prostatic specific antigen seem to be the most useful tests for mass screening of prostate cancer. Transrectal ultrasonography is very useful for guided prostatic biopsy and for a better topographic evaluation of the tumor.

Aged↗
PubMed1990

[Changes in bone volume and mineral density during aging in humans. In vitro study on 80 subjects].

The extent of bone loss was measured and compared at three characteristic skeletal sites: the humerus, iliac crest and vertebrum. The most important effect of ageing is the fall in bone volume: reduction of bone trabeculae, thinning of compact bone and increase in intracortical porosity. Between 40 and 80 years of age, women lose 42 percent of their vertebral spongy tissue, 29 percent of their iliac spongy tissue and 31 percent of humerus cortical bone. The mean degree of mineralization of bone tissue remains constant between 40 and 80 years of age. Cortical bone is mineralized to a greater extent than spongy bone: 1.20 g/cm3 versus 1.0 g/cm3. Bone loss from different skeletal sites varies; within a given bone-organ it varies from one point to another. The mineral content of the iliac crest differs from that of the vertebrum, but the change is parallel at these two sites.

Adult↗
PubMed1989

Artifacts on lung CT scans: removal with Fourier filtration.

A preliminary study was done of Fourier analysis of high-resolution computed tomographic (CT) images of normal pulmonary parenchyma. A two-dimensional fast Fourier transform was applied to 20 regions of interest (64 x 64 pixels) obtained from CT images of six lungs. A qualitative analysis of the spectra and the application of filters in the frequency domain allowed the characterization and removal of reconstruction artifacts. Selective application of a low-pass filter removed these parasitic frequencies and clearly enhanced the quality of the image.

Filtration↗
PubMed1989

[Magnetic resonance imaging of cancer of the prostate. Preliminary study].

Twenty-two patients with prostatic carcinoma have been studied by magnetic resonance imaging (MRI). Twenty-three examinations have been done for 2 stage A, 11 stage B, 2 stage C and 7 stage D. Prostatic signal and locoregional extension have been compared with rectal examination and the 3 prostatectomies. Cancer looked homogeneous in 4 cases, heterogeneous in 10 cases with a nodule in 5 cases either with hyper of hyposignal compared to the normal prostate. Local extension in stages C and D is seen, especially to the periprostatic fat and seminal vesicles. MRI appears to be sensitive but poorly specific in the diagnosis of prostatic cancer. On the other hand, it is an interesting examination in the staging of prostatic cancer. These results must be confirmed with more comparisons of images and prostatectomy specimens.

Aged↗
PubMed1989

[Value of a new non-ionic contrast medium, iopromide 300 in renal arteriography using an arterial route. Comparative study with ioxaglate 320 mgI/ml].

Thirty-nine patients with hypertension were included in a prospective randomized trial comparing two contrast media in intra arterial digital subtraction arteriography of renal arteries. Efficacy and safety were evaluated for a new non-ionic contrast medium, iopromide 320 and the ionic low-osmolar medium, ioxaglate 320 mgI/ml. We have been able to show a statistically significant difference between these two products: iopromide 370 is, in this situation, less painful than ioxaglate 320 mgI/ml.

Angiography, Digital Subtraction↗
PubMed1989

[Contribution of MRI in the staging of cancer of the bladder. Apropos of 40 cases].

56 patients with bladder carcinoma were examined by magnetic resonance in the pre-operative staging. In 40 patients where total cystectomy with enterocystoplasty and pelvic node dissection were performed, a good correlation with surgical and pathologic findings was obtained. MR examination using T1 (TR 400 ms, TE 28 ms) and T2 (TR 1,200-1,600 ms, TE 40 80 120 ms) weighted images in different planes where performed after biopsy of the bladder tumor through endoscopy and within 1 or 2 weeks before surgery. Neoplasms were characterized by site, size and growth pattern. Extension through the deep muscle of the bladder wall was correctly identified in 95% with a sensitivity of 95% and a specificity of 95%. Extension through perivesical fat was assessed accurately in 85% with a sensitivity of 66% and a specificity of 100%. Accuracy in evaluating invasion of adjacent organs was 85%, sensitivity 44%, specificity 96%. Lymphadenopathy has been accurately assessed in 97.5% with a sensitivity of 83% and a specificity of 100%. MR correctly staged the tumor according to TNM classification in 24/40 (60%) patients, overestimated the extension in 3/40 (7.5%) and underestimated the extension in 13/40 (32.5%).

Adult↗
PubMed1989

[Imaging technics in extra-cardiac thoracic amyloidosis].

This report deals with five observations of tracheobronchial, pleuropulmonary and mediastinal amyloidosis. Exploration was performed with plain radiographs, computed tomography in three cases, and magnetic resonance imaging in one case of tracheobronchial and interstitial amyloidosis. After their review of literature, the authors describe the main features of extracardiac thoracic amyloidosis observed with imaging and establish the contribution of the various techniques to the diagnosis and follow-up of the disease.

Aged↗