Search PubMed⌕ Search

Biomedical subjects

J M Bigot

Publications and source records attributed to J M Bigot.

At least 37 records · Page 2Linked to original sources

Anatomic approach to the parametrium: value of computed tomographic in vitro study compared to dissection.

The aim of this study is to describe the morphology of the normal parametrium by correlating the slices obtained with computed tomography of 12 female cadavers studies after intravascular injection of latex with the dissection findings in 6 of the these patients. the upper limit, represented by the isthmus was defined by the uterine a. and/or a superficial uterine v. and/or the coronary v. (Charpy). The lower limit corresponded to the insertion of the levator ani mm. at the junction of the middle and inferior thirds of the vagina. The paracervical and paravaginal tissues above the levator ani m. and medial to the pelvic fascia covering these muscles were perfectly visualized. The posterior limit, formed by the lateral ligament of the rectum and/or the sacrouterine ligaments, and the anterior limit determined by the umbilico-vesical fascia were more difficult to demonstrate. In this study the parametrium appeared as a highly vascular and essentially venous connective structure with a variable morphology dependent on the uterine position.

Aged↗

[Cystic opacity of the posterior mediastinum].

A patient with atypical clinical signs had a thoracic schwannoma in the left paravertebral gutter. Rigorous analysis of the standard x-rays, computed tomography examination and magnetic resonance imaging gave the diagnosis and guided surgical resection. The pathology report confirmed the imaging findings.

Humans↗

[Spiral CT: new clinical indications and special artifacts].

Authors describe the technical principles of volumetric CT, in comparison with the conventional method. New, quick data acquisition related artifacts are demonstrated in the different organs in order to avoid diagnostical faults. Details are given about the special examination parameter settings which are used for searching for particular pathological processes. Advantages, disadvantages, physiological and technical limitations are discussed. Authors present the new clinical applications, especially in the field of vascular and musculoskeletal imaging.

Humans↗

[Staging of cancers of the utero-vagino-vulvar tract].

Cervical and endometrial carcinomas are the most frequent cancers of the female genital tract. Accurate staging of these diseases is crucial in determining the prognosis and the mode of treatment. Clinical evaluation is often inaccurate. Magnetic resonance (MR) using conventional SE sequences (T2 and contrast-enhanced T1 weighted imaging) has become the imaging technique of choice for pretreatment staging of such cancers. Transvaginal and transrectal sonography with Doppler are of limited value. Helicoidal scanner has to be evaluated especially for endometrial carcinomas.

Female↗

[Actinomycotic tubo-ovarian abscess. Contribution of pelvic angioscanner].

Pelvic actinomycosis is uncommon and usually responsible for tubo-ovarian abscesses which are similar in aspect with nonactinomycotic abscesses. They are usually a complication of an intra-uterine device (IUD) that can be absent as in this case. The differential diagnosis is ovarian cancer. The role of the dynamic CT scan for differential diagnosis in this case is presented. Preoperative diagnosis in this affection is important because of the excellent response to Penicillin.

Abscess↗

[Stereotactic core biopsy of breast microcalcifications. Aid to diagnosis?].

We assessed the accuracy with which stereotactic core biopsy of breast microcalcifications helps to justify follow-up or indicate required surgical planning. Eighty-nine patients underwent stereotactic breast biopsy performed with large core needles. Histopathologic findings of microbiopsies were correlated with radiological findings, with follow up and with surgical findings. Agreement between radiological and histopathologic findings on biopsies was obtained in 86% for benign results. Even in the case of benign radiological findings, the histological results of microbiopsies required a surgical biopsy justified in 10% of cases. Radiologically suspicious or malignant microcalcifications were correlated with 35% benign and 65% malignant histologies on biopsies. The positive predictive value, negative predictive value and accuracy were respectively 93%, 86% and 95%. Invasive lesions were found on microbiopsies in 39% of excised malignant lesions. Multifocal lesions were proved on microbiopsies in 50% of all excised carcinomas. Microbiopsies help to disclose malignant lesions undetected on radiological analysis, and may obviate diagnostic surgical biopsy in many cases.

Adult↗

Aortocaval fistulae: a percutaneous model and treatment with stent grafts in sheep.

BACKGROUND: Treatment of aortocaval fistulae (ACFs) by open surgery is known to be a high-risk procedure. In this experimental study, we developed a percutaneous model of ACF to test a new nonsurgical method of treatment of ACF using endovascular stent grafts. METHODS AND RESULTS: An ACF was created percutaneously in eight sheep. Via a combined venous and arterial femoral approach, angioplasty balloons were inserted to occlude the infrarenal aorta and inferior vena cava (IVC). The IVC was punctured through the lateral aortic wall with a transjugular liver biopsy needle. The fistulous tract was then dilated with an 8-mm angioplasty balloon, and the animal was heparinized. Two weeks later, a 10-mm Cragg-Endopro-Stent was inserted into the aorta at the level of the fistula via a percutaneous femoral approach. ACFs were successfully created in all animals, with rapid dye shunt through the fistula and a 20% increase in cardiac pulsations. Follow-up angiograms at 2 weeks showed a patent ACF, and stent implantation excluded the fistula in every case. Angiographic and pathological examinations up to 6 months demonstrated normal aortic patency and persistent exclusion of the fistulae. CONCLUSIONS: ACFs were effectively treated by endovascular grafting of the aorta. The animal model and the stenting procedures were both performed percutaneously.

Angioplasty, Balloon↗

The sacroiliac joint: anatomical study in the coronal plane and MR correlation.

The current clinical imaging technique applied to the sacroiliac joint (SIJ) is coronal Computed Tomography (CT). The aims of this study were: 1) to section the cartilage, the ligaments of the SIJ, and their relations to adjacent organs, in a coronal plane; 2) to correlate anatomical and magnetic resonance (MR) sections; 3) to extend these data in vivo. A topographic dissection of a 52 year-old female specimen was performed to identify the various components, and spatial relationships of the SIJ. Another fresh frozen 50 year-old female cadaver was chosen on CT criteria of normality, and examined with a high resolution (HR) T1-weighted spin echo sequence, in a plane parallel to the ventral limit of the first two sacral vertebrae. This cadaver was then sliced with a sliding gauge device (slice thickness: 5 mm, and device thickness: 1 mm). The SIJ of a 28 year-old nulliparous volunteer, were examined in HR MR imaging, and with a faster sequence, for comparison with the post mortem data. The slice study was correlated with conventional dissection. The continuity and thickness of the auricular cartilage, the complex fascicles of proximal ventral and dorsal sacroiliac ligaments, and distant sacrotuberous and sacrospinous ligaments, were studied. In each plane, coronal HR MR imaging studies were correlated with anatomical sections. The clinical relevance of this comparison was to extend these data in vivo. The auricular cartilage and the ligaments of the SIJ are clearly analyzed by MR imaging, which could contribute to the study of sacroiliitis.

Adult↗

[Imaging of digestive involvements after irradiation].

The main limiting factor of the abdominal and pelvic radiotherapy is radiation damage of the digestive organs. The intestinal abnormalities resulting from irradiation are due to damaged blood vessels and connective tissue. Radiation changes in the small bowel and the recto-sigmoid are frequent and often symptomatic. Imaging is able to detect the induced radiation damage, even the asymptomatic scars. It is relevant to differentiate them from tumoral recurrence. The lesion location within the irradiated volume is important in the evaluation of post-radiotherapy imaging. Computerized tomography (CT) and magnetic resonance imaging (MRI) detect asymptomatic lesions in the liver, spleen and pancreas. We insist on the CT-imaging of induced radiotherapy changes, which are of major importance during the follow-up of irradiated patients.

Acute Disease↗

[Ultrasono-hysterography: techniques and indications].

Sonohysterography consists in injecting a saline solution into the uterine cavity and performing transvaginal sonography. The purpose of this procedure is the pre-operative assessment of intracavitary anomalies, especially polyps, myoma, adhesions, congenital abnormalities such as septate uterus. Technical aspects are shown. This procedure is painless, atraumatic and no adverse effect is seen if the usual precautions before hysterography are taken. The right place of this exam is between hysterography and hysteroscopy, but more widespread use is required before a final opinion can be reached.

Female↗

Bronchogenic cyst presenting as mediastinal mass with pleural effusion.

Mediastinal bronchogenic cysts are usually identified on computed tomography (CT) as well-defined masses of variable density that may contain rim calcifications. Pleural effusion has never been described in association with these cysts. We report two cases of bronchogenic cysts with unusual presentation because of an association with a pleural effusion not explained by pulmonary infection. The patients were studied with CT scan (n = 2) and magnetic resonance imaging (MRI) of the chest (n = 1). In the first case, the pleural effusion directed diagnosis towards lung tumour; and the diagnosis of bronchogenic cyst was made on thoracotomy. In the second case, bronchogenic cyst was suspected on MRI findings. Inflammatory reaction was also suspected on the CT scan, which showed enhancement of the cyst edge. In both cases, surgical excision of the cyst was difficult because of pericystic adhesions to adjacent organs. Therefore, solely on the finding of a pleural effusion, pericystic inflammation had to be suspected.

Bronchogenic Cyst↗

Intrathoracic Kaposi's sarcoma. CT findings.

AIM: To describe the thin CT scans findings in AIDS patients with intrathoracic Kaposi's sarcoma (KS). MATERIAL AND METHODS: Fifty-three CT scans of patients with KS were retrospectively reviewed. The diagnosis of intrathoracic KS was established histologically (n = 17) or on the association of skin KS and the visualization of characteristic endobronchial lesions (n = 36). CT scans were performed with thin slices (2 mm) obtained at 10-mm intervals, and a 512 x 512 reconstruction matrix. No patients had Pneumocystis carinii pneumonia within the 3 months preceding the CT scan examination. RESULTS: Numerous nodules (n = 42), tumoral masses (n = 28), bronchovascular pathways thickening (n = 35), and pleural effusions (n = 28) were the most frequent patterns. Septal lines (n = 15), ground-glass opacities (n = 3), and mediastinal adenopathies (n = 8) were not frequent. CONCLUSION: Numerous nodules, tumoral masses, bronchovascular pathways thickening, and bilateral pleural effusions were the main signs of intrathoracic KS; their association (66%) is very characteristic. An opportunistic infection or mycobacteriosis must be sought if the thin CT scans reveal ground-glass opacities and/or mediastinal adenopathies.

Acquired Immunodeficiency Syndrome↗

[Imaging of lipoma of the pericardium].

Pericardial lipoma is a benign mediastinal tumours. Its location into the pericardial space is well demonstrated by MRI or CT if pericardium is visible; otherwise, diagnosis is evoked on the displacement or compression of cardiac cavities.

Female↗

[Hypoxic cerebral lesions. X-ray computed tomography and MRI aspects. Apropos of 20 cases. Selective vulnerability of the striatopallidum].

Brain lesions following hypoxic-ischaemic injuries are known from autopsy studies, but their appearance in live patients has been only occasionally described, and only sporadic reports have been published on their CT and MRI images. Over a 2-year period (1991-93) we studied the clinical, MRI and CT features in 20 patients shortly after a severe hypoxia. Clinical examination showed motor extrapyramidal signs in 13 cases and coma in 7 cases. MR with inversion recovery (IR) and T2-weighted spin echo (SE) sequences was performed in 17 patients and CT in 15. Bilateral lesions were found in 11 cases, but in 13 of them CT was normal. Radiological lesions were always symmetrical and bilateral, located in the pallidum in 10 cases, the striatum in 4 cases and the thalamus in 2 cases. Additional white matter lesions were present in only 4 MRI examinations. No relationship was found between the mechanism of hypoxia and the severity of clinical signs. The course of the clinical signs was correlated with the presence of radiological lesions. In comatous patients there was a relation between parkinsonism and abnormalities of basal ganglia. None of the patients who had perinatal asphyxia had radiological lesions. The presence of pallidal or striatal confirmed the hypoxic origin of neurological symptoms, especially in patients with parkinsonism. MRI, particularly in IR sequences, makes it possible to detect small lesions in basal ganglia after hypoxic injuries.

Adult↗

[Solid breast nodules: reliability of ultrasonographic and cytological studies].

The authors evaluated the usefulness of US study and US guided fine-needle aspiration cytology (FNAC) in 144 solid breast lesions. US studies was performed with a 10-MHz transducer. Homogenous hypoechogenicity, elongation along the general orientation of the breast tissue plane, regular margins, and intensification of posterior echoes were considered as benign signs. US guided FNAC was performed when lesions were depicted at US. The smears were performed immediately by the cytologist who was present during the procedure. US signs and FNAC diagnoses were compared with surgical/core biopsy diagnoses or negative imaging follow-up. The sensitivity of US was 93%, specificity 75%, accuracy 81%. Among 41 malignant lesions the cytologic findings were malignant (n = 26) or suspicious (n = 7) with 1 false positive and 2 false negative. Inadequate samplings were less frequent last year study (13.5%). The sensitivity of cytologic diagnosis was 94%, specificity 85%, and accuracy 88%. US study and FNAC could be helpful in evaluating solid breast lesions. A better accuracy may be obtained if FNAC is associated with core biopsy.

Adult↗

[Thoracic imaging in AIDS].

Chest complications were the first known in AIDS; even, Pneumocystis carinii pneumonia was the initial warning light. At the present time lung complications remain the major cause of death in such patients. A better knowledge of these pathologies often allows to pass an acute episode and perhaps to prevent infectious pathologies, so, leading to the observation of extra-thoracic pathologies. Preventive treatments and increasing survival time allow the appearance of some atypical aspects of Pneumocystis carinii pneumonia such as apical, necrotic or pseudotuberculous forms. On the other hand, lung tuberculosis is observed with a particular frequency in these patients. It has very rarely a nodular or excavated aspect and looks frequently like a primary tuberculosis. If such infectious chest complications have to be recognized very quickly, we have to know the possibility of non infectious disease, and firstly of Kaposi's sarcoma. Radiological aspect, especially from chest-X-ray, is one of the first diagnostic guide. It gives the orientation for other examinations opposing, disseminated or diffused pneumopathy to focal or localized one. In the first group, we have to distinguish alveolo-interstitial patterns from nodular patterns. Necrotic or suppurative aspects and the association with pleural, mediastinal or hilar lesions are important signs, sometimes better shown on CT scan. Moreover, chest-CT scan is able to guide new endoscopic samples or to guide transthoracic biopsies, allowing sometimes to avoid an open lung biopsy.

AIDS-Related Opportunistic Infections↗