Biomedical subjects
Publications and source records attributed to Y Menu.
Bilateral facet dislocation of the lumbosacral joint is an uncommon injury. We report on the imaging findings in a patient who had an acute disc herniation associated with a bilateral traumatic lumbosacral dislocation.
Osteoarticular manifestations of SAPHO syndrome include vertebral lesions, typically in the thoracic segment. Chronic inflammatory changes are well depicted by MRI. We report the imaging findings with a 10-year follow-up in a case of SAPHO syndrome with marked cervical lesions.
Scar endometriosis is a rare disease which is difficult to diagnose. The symptoms are nonspecific, typically involving abdominal wall pain at the time of menstruation. Clinical examination may reveal a painful nodule, if the scar involved is located on the abdominal wall, but is normal, when the lesion is located on the uterine scar. Other means of investigation (transvaginal ultrasonography, computed tomography) may be useful in case of lesions on the abdominal wall, or if the nodule is large, but give no specific results. The diagnosis is frequently made only after excision of the lesion. We report here 4 patients operated for scar endometriosis (two abdominal and two uterine scars) for whom MRI had suggested the diagnosis. Thanks to its very high spatial resolution, MRI enables very small lesions to be detected and can distinguish the hemorrhagic signal of endometriotic lesions. Furthermore, it performs better than the CT scan in detecting the limits between muscles and abdominal subcutaneous tissues.
OBJECTIVES: Dynamic MR imaging (MRI) may be used as an alternative to dynamic cystoproctography for the evaluation of pelvic floor prolapse. Our study aimed to define the range of dynamic pelvic MRI aspects observed during the exploration of pelvic prolapse. MATERIAL: Fascial and anatomic defects can include a combinaison of cystocele, rectocele, uterine prolapse, enterocele and vault prolapse. Acute diagnosis of the coexisting abnormalities is essential in planning reconstructive procedures so that the risks of recurrence and reoperation can be minimized. At this time colpocystography is the study of choice to evaluate pelvic floor dysfunction. Dynamic magnetic resonance imaging for exploration of pelvic floor dysfunction is under evaluation. RESULTS: Pubococcygeal line and puborectalis muscle were the references points. The grading system is based on degree of organ prolapse through the hiatus and the degree of pubo-rectalis descent and hiatal enlargement. Unfortunately, there is a real discordance between the reality of the prolapse and its imaging. However, a new reference line, the mid pubic line, was drawn on the magnetic resonance image to correspond to the hymeneal ring marker used in clinical staging. Intra-operative findings were considered the gold standard against which physical examination, dynamic colpocystodefecography and MRI were compared. Using these criteria the sensitivity, specificity and positive predictive value of MRI were 70%, 100%, 100% for cystocele; 42%, 81%, 60% for vaginal vault or uterine prolapse; 100%, 83%, 75% for enterocele; 87%, 72% and 66% for rectocele. CONCLUSION: MRI appears to be an important adjunct in the comprehensive evaluation of the female pelvis. Except for vaginal vault, pelvic prolapse is accurately staged and pelvic organ prolapse reliably detected. The technique is rapid, non invasive and cost effective, it allows the clinician to visualize the whole pelvis using a single dynamic study that provides anatomical details.
The central nervous system (CNS) has a particular regional functional anatomy. The morphological support of cognitive functions can now be depicted using functional imaging. Lesions of the central nervous system may be responsible of specific symptoms based on their location. Current neuroimaging techniques are able to show and locate precisely macroscopic lesions. Therefore, the knowledge of functional anatomy of the central nervous system is useful to link clinical disorders to symptomatic lesions. Using radio-clinical cases, we present the functional neuro-anatomy related to common cognitive impairments.
The authors describe a new technique of CT pelvimetry, using multi detector CT. This protocol is able to provide an anatomic view of the bony pelvis as well as classical measurements for pelvimetry. The acquisition is made using low technical parameters allowing the radiation dose to remain similar to that of conventional CT. Helical acquisition with thin slices and interleaved reconstruction provides adequate material for Volume Rendering reconstruction. Presets of the software may give readily available images within seconds, saving time for the radiologist. Although this technique might be performed using single slice helical CT, multi detector CT makes it faster and more accurate as the acquisition time is shorter. Final images are more easily understood by obstetricians and midwives, leading to a better understanding of dystocias. This anatomical information is obviously superior to that of conventional CT. Because it is simple to perform, has no medical time cost for the radiologist if a Volume Rendering software is available, and does not require additional radiation, we believe that this technique should replace conventional CT or conventional pelvimetry.
STUDY OBJECTIVE: To take recent progress in magnetic resonance imaging (MRI) into account to determine its accuracy compared with that of transvaginal ultrasonography (TVUS) in diagnosing bladder endometriosis. DESIGN: Retrospective analysis (Canadian Task Force classification II-2). SETTING: University-affiliated hospital. PATIENTS: Twelve women with histologically proved bladder endometriosis. INTERVENTION: Magnetic resonance imaging with body and endocavitary coils and TVUS. MEASUREMENTS AND MAIN RESULTS: Although TVUS was normal in four patients, MRI enabled endometriotic lesions to be detected in all patients. Magnetic resonance imaging with endocavitary coil established the existence of deep infiltration in three patients when muscularis involvement was not visible with the body coil. In seven women MRI determined how far deep posterior endometriotic lesions extended, whereas with TVUS this was impossible to see. Conclusion. MRI had advantages over TVUS in diagnosing small lesions of associated posterior deep endometriotic lesions. The endocavitary coil gave better results than the phased-array coil for diagnosing deep infiltration. These results are important in that they help guide surgical management.
The liver is a parenchyma which contains many vessels. They are composed of two inflow vessels: the portal vein and the hepatic artery, and one outflow system represented by the hepatic veins. We will see in the chapter most of the abnormalities and their consequences due to decrease or an increase of the blood flow of these vessels. Many illustrations will be provided with a special focus on CT findings with multiphasic images.
PURPOSE: Presentation of a clinical audit of the radiology reports in our institution. MATERIAL: and methods: This audit has been performed in several steps: launching the project, elaboration of the reference book, elaboration of the protocol, analysis of the results, improvements made. RESULTS: Several dysfunctions were detected: typing errors, the lack of sentences explaining the procedure of examination, the lack of negative pertinent elements, the lack of synthesis. Several interventions were made: checking on the screen of the computer the report before signing it, purchase of personal voice recorders, restructuring the interpretation room. Other interventions are considered: structured data entry, P.A.C.S. systems CONCLUSION: This audit has allowed the modification of the process for realisation of the radiology reports and the stimulation of the medical team, thus improving the quality of our work.
We present the imaging findings of superficial siderosis of the central nervous system associated with an ependymoma of the posterior fossa in a patient who presented with progressive bilateral sensorineural hearing loss and cerebellar ataxia. The ependymoma was a homogeneous well-defined mass of the fourth ventricle without hydrocephalus. Secondary siderosis due to chronic bleeding from the ependymoma appeared as linear hypointensity delineating the surface of the cortex, thin and subtle on spin-echo T2-weighted images, thick and obvious on gradient-echo T2-weighted images.
We report the MRI findings of six unusual lesions of the internal auditory canal: three haemangiomas, one lipoma, one metastasis and one traumatic neuroma. We compare the findings to those of 20 intracanalicular schwannomas. We noted the site and size of the tumour, its signal intensity, borders and the homogeneity of enhancement were studied on T1-weighted images before and after intravenous contrast medium and T2-weighted images. Most schwannomas were homogeneous lesions, isointense on T1- and T2-weighted images, and strongly enhancing. Spontaneous high signal on T1-weighted images, heterogeneous contrast enhancement and extranodular enhancement were helpful for recognising lesions other then schwannomas; site, size and signal on T2-weighted images were not. All the haemangiomas had a specific pattern of contrast enhancement, with an anterior core intensely enhancing portion and a posterior portion which enhanced moderately or not at all.
OBJECTIVE: We evaluate the uniformity and reproducibility of thermal lesion ablation and quantify the volume of tissue destruction and hemorrhage induced with two different commercially available radiofrequency ablation devices. MATERIALS AND METHODS: A four-array anchor expandable needle electrode and a triple-cluster cooled-tip needle electrode were used to induce lesions in three explanted calf livers and in vivo in eight swine livers. The sizes of the radiofrequency-induced lesions were macroscopically evaluated by measuring two perpendicular dimensions immediately after the experiment. Bleeding was evaluated by weighing gauze swabs used to dry the hemorrhage caused by electrode insertions. RESULTS: In explanted liver, the mean diameter of the radiofrequency-induced lesion was 5.3 +/- 0.7 cm for the cooled-tip needle and 3.7 +/- 0.4 cm for the expandable needle (p = 0.042), which correspond to approximate volumes of 65.35 +/- 26.22 cm(3) and 26.67 +/- 9.59 cm(3), respectively (p < 0.002). In vivo, the mean diameter was 3.7 +/- 0.4 cm for the cooled-tip needle and 3 +/- 0.4 cm for the expandable needle (p < 0.0001), which correspond to approximate volumes of 24.18 +/- 7.56 cm(3) and 11.16 +/- 3.65 cm(3), respectively (p < 0.0001). Blood loss attained a median value of 3.5 g for the cooled-tip needle and 2.6 g for the expandable needle; this difference was not statistically significant (p = 0.06). CONCLUSION: The cooled-tip needle induced significantly larger lesions than the expandable needle, but the lesions produced by the expandable needle are more reproducible, uniform, and spheric. The larger size of the lesions produced by the cooled-tip needle may be attributed to the higher maximum power used by the generator and the higher energy deposition, which is due to the cooling of the needle electrode.
PURPOSE: Elaboration of a tool for an Audit of radiology reports in a department of radiology. Materials and methods. We have made a grid and a guide to evaluate the relevance and the quality of the radiology reports. We have tested this tool on 120 reports from in-patients of the gastroenterology department. The test has been done by two radiologists (blinded test) to verify if the answers were identical. We have calculated for each item the Kappa coefficient (inter-observer agreement). RESULTS: This study has validated most of the items of our grid, some have been deleted, and others modified. CONCLUSION: Our study shows that our tool can evaluate the radiology reports of a radiology department, an audit can thus be conducted using that tool.
The aim of this study was to describe the intrahepatic hemodynamic modifications induced by right portal vein embolization (RPVE) using Doppler ultrasound. Eighteen patients with hepatocellular carcinoma (n = 8), liver metastases (n = 9), or multiple adenomas, underwent RPVE 1 month before right hepatectomy in order to increase the size of future remnant liver. Doppler ultrasound was performed before and 1 month after RPVE. The portal vein flow and the hepatic artery resistive index in right and left lobes (segments V and III) were calculated. We recorded simultaneously artery and portal vein of segment III to measure the arterioportal ratio calculated as follows: (maximal arterial systolic velocity minus maximal portal vein velocity)/maximal arterial systolic velocity. Results were compared in cirrhotic patients (group A) and in healthy liver patients (group B). In both groups, portal flow was not significantly modified following RPVE. In the left lobe, in both groups the hepatic artery resistive index was not significantly modified. In group B, the arterioportal ratio decreased significantly (0.71 +/- 0.18 and 0.42 +/- 0.23, respectively, before and after embolization; p < 0.01), whereas it was not statistically modified in group A (0.75 +/- 0.17 and 0.69 +/- 0.14, respectively, before and after embolization). The right hepatic arterial resistive index decreased significantly in both groups after embolization (0.74 +/- 0.07 to 0.66 +/- 0.07, p<0.05; and 0.66 +/- 0.07 to 0.61 +/- 0.06, p < 0.05, respectively, before and after RPVE for groups A and B). Total portal flow was unchanged after RPVE (750 +/- 337 ml/mn and 696 +/- 231 ml/mn, respectively, before and after RPVE). The hepatic artery resistive index was unchanged before and after embolization in the left lobe (0.75 +/- 0.13 and 0.74 +/- 0.14, respectively), but significantly decreased in the right lobe (0.7 +/- 0.08 and 0.62 +/- 0.06 respectively, p < 0.05). The left arterioportal ratio decreased significantly from 0.76 +/- 0.17 to 0.52 +/- 0.23 after PVE, p < 0.02). Our study confirms that right portal occlusion induces a decrease in hepatic artery resistive index in the right lobe and does not modify total portal flow. The left and right lobes of the liver have separate arterioportal regulation.
BACKGROUND: Hepatic arterial chemoembolization (CE) with anthracyclines is an effective treatment for progressive liver metastases of digestive endocrine tumours. Streptozotocin (STZ) is widely used for systemic chemotherapy, but its efficacy by the hepatic arterial route has not been evaluated. PATIENTS AND METHODS: Fifteen consecutive patients, mean age 57.8 years, were prospectively included between July 1993 and January 1997. All patients had progressive liver metastases from either a carcinoid tumour (eight patients) or an islet cell carcinoma (ICC) (seven patients) that had increased in size (> or = 25%) before CE. Five patients had the carcinoid syndrome. STZ was administered, as an emulsion with iodized oil, into the hepatic artery before embolization with gelatin sponge particles. Two to six procedures (median, 3) were performed in 12 patients (one in three patients). Changes in the size of the liver metastases were evaluated by CT scan or MRI according to WHO criteria. The median follow-up was 15 months (1-50). RESULTS: An objective response was achieved in 8/15 patients (53%; median duration of 10.5 months) whatever the primary tumour (carcinoid or ICC). The carcinoid syndrome disappeared in 3/5 patients for 10, 11 and 17 months, respectively. CE effectively controlled hypoglycaemic attacks (decrease of > 50%) in the patient with insulinoma. The biological response was complete in four patients for a median duration of 7 months. CE induced minor side effects, namely nausea, fever and abdominal pain. Acute and reversible tubular necrosis due to CE was observed in one patient who had previously undergone a nephrectomy. CONCLUSION: Hepatic arterial chemoembolization with STZ is an effective treatment for patients with liver metastases caused by digestive endocrine tumours.
PURPOSE: To evaluate the accuracy of preoperative computed tomography (CT) in predicting the location and type of ductal involvement and malignant transformation in intraductal papillary mucinous (IPM) pancreatic tumors and to determine the predictive factors for malignancy at CT. MATERIALS AND METHODS: The helical CT scans obtained in 36 operated on patients with a diagnosis of IPM pancreatic tumor were retrospectively assessed. CT-histopathologic correlation was then performed. RESULTS: The final diagnoses of IPM tumor were combined type (n = 26) and branch duct type (n = 10) lesions. Histologic analysis revealed adenocarcinoma (n = 9), hyperplasia (n = 8), low-grade dysplasia (n = 12), and high-grade dysplasia (n = 7). The lesions were located mainly in the head or uncinate process (n = 20) or were diffuse or multifocal (n = 12). In 12 patients (13 cases), CT-histopathologic correlation was poor, including that in the evaluation of ductal involvement (n = 7), evaluation of lesion location (n = 2), and diagnosis of malignant transformation (n = 4). The most specific predictive signs of malignancy were presence of diabetes and, at CT, a solid mass, main pancreatic duct dilatation greater than 10 mm, diffuse or multifocal involvement, and attenuating or calcified intraluminal content. CONCLUSION: The main causes of poor CT-histopathologic correlation were related to evaluation of main pancreatic duct involvement and diagnosis of malignant transformation. The association between diabetes and specific CT criteria was highly suggestive of malignancy.
Medical Images are components of the so-called "Medical Imaging Folder". This folder is a subset of the so-called "Medical Folder", part of the "Patient Folder. The G8 promotes the concept of a "Global Information Society for Health. Within this society, the Patient Folder is seen either from a healthcare organization, from a country or from an international point of view. The Global Patient Folder (Healthcare Folder) is composed of the different Patient Folder instances. Presently, Pacs and Telemedicine are no longer concerned only by storage and transmission issues. The medical images have only meaning associated with their context, the patient healthcare status. This context is rich in information provided by various information systems or healthcare professionals. The different data are linked and time dependant. Therefore, the expert community in the field of patient records argues that the approach must be the integration of Medical Images within the patient folder. It appears clearly that the complete deployment of such an "International Healthcare Folder" needs time and will proceed in several steps. Due to the increase of the people's mobility this deployment is inescapable. Infrastructure must be sized up taking into account the Digital Medical Image spreading and its large data volume which necessitates a large bandwith. In this paper, we detail the Medical Image Folder concept and its position within the Patient Folder and the Healthcare Folder. Then we present PACS, networking and Telemedicine concepts as well as the needs in standards.
PURPOSE: To analyze the imaging features of nodules associated with Budd-Chiari syndrome. MATERIALS AND METHODS: The authors retrospectively studied images obtained in 23 patients with liver nodules who were being followed up for Budd-Chiari syndrome. Doppler ultrasonography was performed in all patients, computed tomography in 16, and magnetic resonance (MR) imaging in 20. The following lesion features were evaluated: location, number, size, vascularization, qualitative signal intensity at MR imaging, and homogeneity. Nodules were diagnosed on the basis of histopathologic findings or clinical and biologic data with no change at imaging during 2-year follow-up. RESULTS: All patients had histopathologic features of chronic Budd-Chiari syndrome. Four patients had hepatocellular carcinoma (HCC), with one to three lesions. The mean diameter of the largest HCC lesion in each patient was 7.3 cm. All HCC lesions were heterogeneous and had high signal intensity on T2-weighted MR images. Nineteen patients had multiple benign regenerative nodules, most of which were smaller than 4 cm. Most nodules were homogeneous and hyperintense on T1- and T2-weighted images. In 15 patients, nodules were hypervascular in the arterial phase. CONCLUSION: In patients with chronic Budd-Chiari syndrome, multiple (> 10) small (< 4-cm) lesions are suggestive of benignity.