Biomedical subjects
Publications and source records attributed to J M Bigot.
Indications for sialography have became rare and radiologists are less and less experienced for salivary gland cannulation. MR Sialography allows opacification of salivary ducts without any cannulation and could replace residual indications for sialography. The purpose of this paper is to review the principle of the technique, the normal and pathologic aspects of MR Sialography and to emphasize advantages and limitations compared to other techniques.
PURPOSE: To describe the MR appearance of extra-abdominal desmoid fibromatosis, especially using sequences such as MR angiography, STIR and FAT SAT. Materials and methods. We reviewed retrospectively the MRI studies of 8 patients (4 men and 4 women) with histologically proved desmoid fibromatosis. In five patients the lesion corresponded to recurrent disease. Eleven MRI examinations were available (Siemens, Vision, 1.5T) including the following sequences: pre- and postcontrast T1 weighted (11 cases), STIR (9 cases), and MRA (3 cases). All lesions were imaged in at least two orthogonal planes. CT was available for 5 patients. RESULTS: The lesions were localized to the girdles in 8 cases and to the upper extremity in 3 cases. Most lesions (10/11) were isointense to muscle on noncontrast T1W images and showed intense enhancement on postcontrast T1W images. All lesions (9/9) were hyperintense on STIR images. CONCLUSION: A STIR sequence is useful as a first sequence to identify smaller lesions (usually recurrences) and to better adapt the FOV of following sequences, especially before administration of intravenous contrast. MR angiography may be valuable for surgical planning.
PURPOSE: To experimentally evaluate gadolinium (Gd)-, carbon dioxide (CO(2))-, and iodixanol-enhanced digital subtraction angiography (DSA) versus histomorphometry in the assessment of renal artery stenosis. MATERIALS AND METHODS: Fifteen male New Zealand White rabbits weighing 4.0 kg underwent percutaneous catheterization. Renal artery stenosis was induced by bilateral overdilation-deendothelialization (balloon diameter = 2 mm). The percentage of artery overdilation was 33%. After 4 weeks, the rabbits were randomized into two groups: group A underwent right-sided therapeutic percutaneous transluminal renal angioplasty (PTRA) (balloon diameter = 1.5 mm). After another 4 weeks, the renal arteries were evaluated by gadoterate-, iodixanol-, and CO(2)-enhanced selective quantitative DSA. The rabbits were then killed and renal arteries were perfusion-fixed for 60 minutes. Serial orcein-stained 4-um-thick slices were prepared for histomorphometry. RESULTS: Based on morphometric data of single-stenosis versus post-PTRA restenosis lesions, no significant difference was observed between Gd- and iodixanol-enhanced quantitative DSA (r(2) > 0.95), although the iodine/Gd density ratio was equal to 3.5. Carbon dioxide less reliably allowed quantitative DSA (r(2) < 0.75). CONCLUSION: Gd-based contrast agents represent a highly reliable alternative in experimental quantitative DSA evaluation of renal artery restenosis.
OBJECTIVE: To compare the efficiency of air-filled albumin microspheres (Infoson) with saline solution in determining Fallopian tube patency during hysterosalpingo contrast sonography (HyCoSy). METHODS: This was a prospective randomized multicenter study with a sequential design. Over a 10-month period, 23 patients (mean age, 33 years) referred for infertility were examined by HyCoSy (saline or Infoson) before conventional hysterosalpingography (Iopamiron 370), performed during the same session. Contrast agents were administered through a 5-F Ackrad balloon catheter inserted transcervically into the uterine cavity. HyCoSy was performed with a 7-MHz transvaginal probe using both B-mode and color Doppler, and tubal patency was demonstrated by the appearance of contrast agent in the peritoneal cavity near the ovaries. Data were registered for each patient during the examination and the results were monitored by sequential analysis. RESULTS: Mean volumes of contrast injections were 35.3 mL of saline, 14.4 mL of Infoson, and 13.8 mL of Iopamiron 370. Infoson-enhanced HyCoSy provided a significantly larger (P = 0.006) number of correct diagnoses (20/22 Fallopian tubes) than did saline HyCoSy (12/24 Fallopian tubes), and the same number as that achieved by hysterosalpingography. CONCLUSION: A positive ultrasound contrast agent appears to be more efficient than saline solution at determining Fallopian tube patency in infertile women by means of HyCoSy, and as efficient as an iodinated contrast agent in the same population explored by HSG. HyCoSy could be used to screen infertile women, thereby avoiding the use of iodinated contrast medium and exposure to ionizing radiation during conventional HSG in patients with patent Fallopian tubes.
BACKGROUND: The purpose of this study was to evaluate the feasibility, safety, and potential role of gadoterate meglumine (Gd-DOTA) as a contrast agent for upper extremity venography before the creation of an arteriovenous fistula (AVF) for nondialyzed renal insufficiency patients. METHODS: Over a 16-month period, 50 venographies were performed on end-stage renal insufficiency patients, using Gd-DOTA as a contrast agent on a high-resolution digital subtraction angiography system. Three sequences were performed on forearm, arm, and chest at 3 mL/sec for a total of 35 mL of Gd-DOTA. Examinations were reviewed by two radiologists for diagnostic and opacification quality. Tolerance was evaluated on the evolution of serum creatinine levels and occurrence of pain during injection. RESULTS: Good interobserver correlation was obtained in evaluating the feasibility of AVF creation by vein segment (0.64 < kappa < 0.88) and in relationship to opacification quality (0.62 to 0.87). No deterioration in renal function (creatinine level before and after) or pain was observed. Twenty-six patients underwent surgical creation of brachiobasilic (N = 8), brachiocephalic (N = 8), radiocephalic (N = 8), and cubitocephalic (N = 1) fistulas or insertion of a polytetrafluoroethylene (PTFE) graft (N = 1). Seventeen were awaiting AVF or were on peritoneal dialysis. Two died before surgery for reasons unconnected with the venography. CONCLUSIONS: Venography with Gd-DOTA is an effective and safe technique in planning AVFs for renal insufficiency patients.
Acute calcific retropharyngeal tendinitis is a rare entity that often is initially misdiagnosed a retropharyngeal abscess and treated with IV administration of antibiotics. In our 2 cases, imaging enabled a correct diagnosis to be made. Two patients were admitted to the hospital with dysphagia, severe neck discomfort and fever. Lateral radiographs of the cervical spine and CT were obtained in both cases, while MRI was obtained in one case. Calcification of the prevertebral muscles was demonstrated by CT in both cases, and detected on lateral radiographs in only one case. Soft tissue swelling was noted at CT and MRI. A clinical diagnosis of calcific retropharyngeal tendinitis may be difficult to achieve and a definitive diagnosis can be confirmed at imaging studies.
A 35-year-old man with a long history of left L5 radicular pain was found to have an intraspinal cystic lesion causing radicular compression. Magnetic resonance imaging demonstrated a round lesion situated in the anterior epidural space, with uniform high signal intensity on T2-weighted sequences characteristic of a cystic lesion. During surgery a liquid-containing cyst originating from the posterior longitudinal ligament was punctured and resected. The histologic aspect was that of a ganglion cyst without synovial layers. The radiologic differential diagnoses are discussed.
PURPOSE: To describe the features of bronchogenic carcinoma (BC) on plain radiography and computed tomography (CT) in human immunodeficiency virus (HIV)-infected patients; to evaluate percutaneous transthoracic needle biopsy (PTNB) in this setting; and to assess outcome. PATIENTS AND METHODS: We reviewed the medical charts, radiographs and chest CT scans in 15 AIDS patients with histologically proven BC. All but one of the patients were young men (mean age 48 years) with a long history of smoking (mean 40 pack-years). Adenocarcinoma was the predominant cell type (46.6%). The stage of the malignancy did not correlate with the CD4 cell count (mean 189 per mm(3)). The diagnosis was obtained by means of PTNB (n=7), bronchoscopy (n=4), thoracotomy (n=2), pleural biopsy (n=1) or extrathoracic biopsy (n=1). RESULTS: Parenchymal masses and nodules were the most common features (66.6%) on chest radiographs and CT. BC was peripheral in 11 cases (73%) and was located in the upper lobe in ten cases (66.6%). Enlarged lymph nodes were present in 60% of patients and metastases in 30%. PTNB was diagnostic in seven of the eight patients who underwent the procedure; complications included two pneumothoraces and one secondary implantation of tumor cells along the needle tract. Three lobectomies and one pneumonectomy were performed for stage I disease. The mean survival time among the patients who underwent surgery was 14 months. These survivals are more encouraging than some of those previously reported in the literature, furthermore, patients die of competing illnesses. CONCLUSION: BC in HIV-infected patients is similar to that in the general population. Early diagnosis can be achieved by means of PTNB. Surgical resection, when feasible, significantly improves survival.
OBJECTIVE: To decrease the number of open excisional breast biopsies, percutaneous breast biopsies have been developed to perform the histologic diagnosis of non-palpable breast lesions. Some techniques allow a complete removal of small radiologic lesions. To evaluate the accuracy of a pathologic analysis performed only on the radiologic findings, we studied the radiologic and histologic correlation on open excisional biopsy (OEB) specimens. The aim of our study was to determine how many carcinomas were found distant from the radiologic findings. MATERIAL AND METHODS: Non-palpable breast lesions have been excised after preoperative localization. The radiologic findings were classified in microcalcifications, masses, architectural distortion and in sonographic masses. The correlation between the radiologic and pathologic findings was studied and all the lesions incidentally discovered on histology with no correlation with the imaging findings or distant from the radiologic findings were described. One hundred and twenty-nine lesions have been evaluated in 99 patients. Radiologic findings included 79 clusters of microcalcifications, 30 masses, six architectural distortions and 14 sonographic lesions. RESULTS: The histopathological results were benign in 41.9%, malignant in 49.6% and atypical hyperplasia lesions were discovered in 8.5%. All benign lesions were correlated to radiologic findings. No malignant lesion was found at a distance. In three cases atypical hyperplasia lesions were coexistent with the radiologic findings correlated with benign lesions and in three cases they were found at a distance. All but two malignant lesions were correlated with radiologic findings. In two cases a microinvasive carcinoma and foci of labular carcinoma in situ were found coexistent with benign lesions. The subgroup of small lesions lesser than 10 mm included 31 benign lesions. A complete removal of these lesions should be obtained with percutaneous biopsies. CONCLUSION: A pathologic analysis targeted on radiologic findings is accurate. Numerous open excisional biopsies performed for benign pathology should be avoided.
OBJECTIVE: Helical CT scan (HCT), a noninvasive method, can detect pulmonary arteriovenous malformations (PAVMs). Its sensitivity is superior to that of global digitalized angiography, but patients receive a significant dose of radiation during diagnostic HCT. We compared HCT to contrast-enhanced pulmonary magnetic resonance angiography (CEMRA), a new noninvasive radiation-free method, in the diagnosis of PAVMs. PATIENTS AND METHODS: Five consecutive patients with PAVMs underwent HCT, CEMRA, and pulmonary artery digital subtraction angiography (PADSA). CEMRA was performed during the pulmonary arterial phase of an IV bolus of gadolinium. PADSA was performed during the embolization procedure. All images were examined for PAVMs. The site and size of aneurysms were specified, as well as the diameter of the vascular pedicles. RESULTS: Thirty PAVMs were detected by CEMRA and 38 by HCT. All 20 PAVMs at least 5 mm in diameter and 10 of the 18 PAVMs < 5 mm in diameter identified on HCT were also identified by CEMRA. Whatever the site, all PAVMs with a feeding artery diameter of at least 3 mm (ie, PAVMs with clinical consequences) were detected by CEMRA. No false-positive results were obtained with CEMRA. CEMRA therefore had a sensitivity of 78% and a specificity of 100%. CONCLUSIONS: CEMRA, a nonionizing and noninvasive procedure, has high sensitivity and specificity for the diagnosis of clinically relevant PAVMs.
PURPOSE: We assessed the value of breath-hold, gadolinium (Gd) enhanced magnetic resonance urography for diagnosing urinary tract disease. MATERIALS AND METHODS: Dynamic magnetic resonance urography was performed in 38 consecutive patients presenting with urological disease in whom excretory urography was contraindicated. Renal function was impaired in 18 cases with a serum creatinine of 140 to 400 micromol./l. Fast spoiled, gradient echo sequences were acquired during breath-holding 5, 10 and 15 minutes after intravenous injection of 10 ml. of a Gd chelate. Opacification of the collecting system was evaluated using a scale of 0 to 3. Diagnostic value of the examinations was also analyzed. RESULTS: Dynamic magnetic resonance urography was sufficient for making the diagnosis in 95% of cases. We identified 71 pathological findings and the surgical anastomosis was always well visualized. Mean image quality score was 2.34 points for renal calices, 2.86 for renal pelves and 2.48 for ureters. Image quality significantly improved after injecting a diuretic. CONCLUSIONS: Gd enhanced magnetic resonance urography provides quality dynamic imaging of the urinary tract. It is a new approach for diagnosing urinary tract disorders in patients in whom excretory urography should be avoided.
To assess the morphology of the suspensory ligament of the ovary on CT scan examination, an anatomic study of the suspensory ligament of the ovary was performed to demonstrate its morphology on CT and to facilitate the visualization of the ovaries. Twelve female cadavers were studied after intravascular injection of latex (venous: 2, arterial: 6, arterio-venous: 4). We first observed all the pelvises after their transection. Six dissections were then made to obtain optimal anatomic correlations on the content and relations of the infundibulo-pelvic ligament. The arterial opacifications were poor compared with to the good quality of the venous or arteriovenous opacifications. An upright correlation between CT slices and the anatomic study was made. This radio-anatomic study emphazises the importance of the veins, which really support the suspensory ligament of the ovary, as opposed to the involution of the arteries. This study points out the link between the infundibulo-pelvic ligament above and the utero-ovarian below, then with the superficial uterine vv. All these structures were well analyzed on CT and during the anatomic studies. A very well developed periovarian venous plexus which frequently concealed the ovaries was demonstrated. Some anatomic variations which were invisible on the CT scan examinations were displayed. The visualization of the suspensory ligament of the ovary should facilitate the visualization of the ovaries and could optimize the search for lymphadenopathies originating from ovarian cancers.
STUDY OBJECTIVES: To describe the radiographic and CT findings of primary AIDS-related lymphoma (ARL) of the lung (ARLL), and to evaluate percutaneous transthoracic needle biopsy (PTNB) in the diagnosis of primary ARLL. MATERIALS AND METHODS: Seven chest radiographs and seven CT scans of HIV-infected patients with histologically proved primary pulmonary non-Hodgkin's lymphoma (PPL) were reviewed at our institution. All of the patients had fibroscopy with BAL. The diagnosis of PPL was established histologically by means of PTNB (n = 4), open-lung biopsy (n = 2), or autopsy (n = 1). RESULTS: All but one patient had multiple peripheral well-defined nodules of various sizes on the chest X-ray film and CT scan. One patient had a subpleural parenchymal infiltrate and another had a main peripheral mass with spontaneous cavitation. Hilar/mediastinal adenopathies and pericardial/pleural effusion were never associated with the parenchymal abnormalities. Fibroscopy with BAL was always negative. PTNB, done in six cases, was diagnostic in four cases and suggested primary ARLL in two cases. No complications occurred during these procedures. CONCLUSION: After excluding infectious causes, multiple peripheral nodules and/or masses without hilar or mediastinal adenopathies and without pleural effusion are suggestive of primary pulmonary ARL. A specific diagnosis can be obtained by means of PTNB.
Technical aspects of 3D contrast-enhanced magnetic resonance angiography are exposed, detailing more particularly the pulse sequence used and the mode of injection of contrast agent. Then, various vascular territories are analyzed, and illustrated using various examples of main pathologies observed in routine clinical practice: abdominal aorta, renal arteries, pelvic and mesenteric vessels, and peripheral arteries.
Glomus tumor is a neuro-myo-arterial benign tumor accounting for 1 to 5% of hand tumors which occurs principally in young adult females. It may be unique or multiple. Acute, focalized, pain is the main sign, the pressure of a small trigger zone induces a syncopal pain and immediate hand withdrawal. Differential diagnoses includes neurinoma, melanoma, hematoma, osteoid osteoma, fibrokeratoma, mucoid cyst, angioma, and exostosis. The diagnosis is suspected on clinical grounds, and X rays exhibits a bone erosion in one third of the cases. Magnetic resonance angiography is now the first line non invasive tool for both diagnosis and precise localization. Treatment consists in complete surgical tumor resection (J Mal Vasc 1999; 24: 364-367).
The purpose of this study was to describe magnetic resonance findings of intradural spinal canal secondaries and to select the best way of investigating this condition. Thirty patients with a known malignancy [breast carcinoma (n = 14), lung carcinoma (n = 10), other sites (n = 6)] and unexplained neurologic signs were studied with pre- and post-contrast T1-weighted images and T2-weighted images. Cerebrospinal fluid cytology was available in 16 patients and positive in 11 patients. In all the patients, post-contrast T1-weighted images demonstrated abnormal enhanced lesions. Most of them were nodular, located on the conus medullaris and the cauda equina. Few lesions appeared at the thoracic or cervical levels, as nodular or thin areas of enhancement. Pre-contrast T1-weighted sequences failed or were equivocal to detect the lesions. Eighteen of 30 patients had cerebral metastases. Fourteen had osseous metastases. In conclusion, post-contrast T1-weighted sequence is the optimal modality for the diagnostic of intradural spinal canal metastases. Axial and coronal images may be a useful adjunct to precise anatomic changes. T1-weighted and T2-weighted sequences remain necessary when further information is expected on vertebra or soft tissue.
RATIONALE AND OBJECTIVES: The authors determine the feasibility of creating renal artery stenosis by overdilatation and deendothelialization and compare the model in normocholesterolemic versus hypercholesterolemic rabbits. METHODS: Thirty male New Zealand White rabbits were randomized into two groups: group A (n = 15) was fed a normal diet and group B (n = 15) was fed a cholesterol-rich diet 4 weeks before stenosis induction. An aortogram was performed, then the right renal artery was overdilated with an angioplasty balloon-catheter, and deendothelialized. After 6 weeks, groups A and B were compared by angiographic and pathologic study. RESULTS: Comparison of group A versus group B showed that 12 arteries (80%) versus 6 (40%) were angiographically stenotic (P < 0.05); 14 (93%) versus 12 (80%) contained neointima (NS), 12 (80%) versus 3 (20%) showed medial disorganization (P < 0.01), and 9 (60%) versus 2 (13%) presented adventitial fibrosis (P < 0.01). CONCLUSIONS: A new model of endovascularly induced renal artery stenosis has been developed in rabbits. Medial proliferation and adventitial fibrosis are more frequent in normocholesterolemic rabbits.