Flow measurements in sewers based on image analysis: automatic flow velocity algorithm.

Discharges of combined sewer overflows (CSOs) and stormwater are recognized as an important source of environmental contamination. However, the harsh sewer environment and particular hydraulic conditions during rain events reduce the reliability of traditional flow measurement probes. An in situ system for sewer water flow monitoring based on video images was evaluated. Algorithms to determine water velocities were developed based on image-processing techniques. The image-based water velocity algorithm identifies surface features and measures their positions with respect to real world coordinates. A web-based user interface and a three-tier system architecture enable remote configuration of the cameras and the image-processing algorithms in order to calculate automatically flow velocity on-line. Results of investigations conducted in a CSO are presented. The system was found to measure reliably water velocities, thereby providing the means to understand particular hydraulic behaviors.

Vision-based system for the control and measurement of wastewater flow rate in sewer systems.

Combined sewer overflows and stormwater discharges represent an important source of contamination to the environment. However, the harsh environment inside sewers and particular hydraulic conditions during rain events reduce the reliability of traditional flow measurement probes. In the following, we present and evaluate an in situ system for the monitoring of water flow in sewers based on video images. This paper focuses on the measurement of the water level based on image-processing techniques. The developed image-based water level algorithms identify the wall/water interface from sewer images and measure its position with respect to real world coordinates. A web-based user interface and a 3-tier system architecture enable the remote configuration of the cameras and the image-processing algorithms. Images acquired and processed by our system were found to reliably measure water levels and thereby to provide crucial information leading to better understand particular hydraulic behaviors. In terms of robustness and accuracy, the water level algorithm provided equal or better results compared to traditional water level probes in three different in situ configurations.

[Pseudotumoral presentation of American pulmonary histioplasmosis]. / Présentation pseudo-tumorale de l'histoplasmose pulmonaire américaine.

In France, American pulmonary histoplasmosis is an imported deep mycosis, caused by inhalation of Histoplasma capsulatum. Clinical and radiological features of this exotic disease are multiple, simulating tuberculosis or cancer. We report two cases of American histoplasmosis with pseudo-tumoral form, in immunocompetent subjects working in Venezuela, with a multinodular pulmonary presentation.

Application of new imaging and calculation techniques to activity and dose assessment in the case of a 106Ru contaminated wound.

The aim of this paper is to describe the dosimetric evaluation of a point contamination that occurred in a laboratory during the examination of an irradiated sample. The incident led to point contamination of the operator's finger due to the presence of mainly 106Ru, with its progeny, 106Rh. The paper reports on the activity and dose assessment, performed using several methods. The measured activity was obtained using a conventional device based on a germanium detector and confirmed using software developed at IRSN, based on reconstruction of voxel phantom associated with the Monte Carlo N-Particle code (MCNP) for in vivo measurement. Two dose assessment calculations were performed using both analytical and Monte Carlo methods, applying the same approach as for activity assessment based on the personal computational phantom of the finger. The results are compared, followed by a discussion on the suitability of the tools described in this study.

[Inflammatory pseudo-tumor of the lung. Clinico-pathologic report of a case]. / Pseudo-tumeur inflammatoire du poumon. Etude anatomo-clinique d'une observation.

One case of a solitary pulmonary nodule occurring in a 54-year-old woman with history of breast carcinoma is presented. Histological examination of the surgical specimen excluded breast carcinoma metastasis and revealed an inflammatory pseudotumor. Principal clinico-pathological findings in previously reported cases are described. Inflammatory pseudotumors may exhibit, as in our case, some nuclear atypia making the diagnosis sometimes difficult with malignancy.

[Asymptomatic pulmonary embolism and venous thrombosis of the lower limbs. Study with spiral x-ray computed tomography]. / Embolie pulmonaire asymptomatique et thrombose veineuse des membres inférieurs. Etude par tomodensitométrie hélicoïdale.

AIM: Spiral Computed Tomography (CT) allows diagnosis and follow-up in pulmonary embolism (PE). MATERIAL AND METHOD: We studied prospectively with spiral CT 21 patients to evaluate the frequency and the extent of asymptomatic PE in the patients with lower limbs venous thrombosis and no pulmonary symptomatology. RESULTS: We observed a asymptomatic PE in 8/21 cases (34%). Extensive pulmonary thrombosis could be observed despite normal presentation. There was no association between the localization of PE topography and, the extent of the lower limb venous thrombosis extent. CONCLUSION: This study shows about the capability for CT to evaluate PE severity and clinical underestimation PE occurrence.

[Diagnosis of renal, peri- and para-renal infections. Contribution of ultrasonics and x-ray computed tomography. Apropos of 10 cases]. / Diagnostic des infections rénales, péri et para-rénales. Apport de l'échographie et de la scanographie. A propos de 10 observations.

Principal signs and symptoms of renal parenchyma infections are discussed in relation to findings in 10 cases. Disorders studied were acute pyelonephritis and focal and bacterial acute nephritis, renal abscess and perinephritic phlegmon. Intravenous urography was only moderately sensitive (4/7) and of little specificity. Ultrasound imaging showed much greater sensitivity (8/10), undetected lesions being the earliest cases of severe acute pyelonephritis. The scanner was the most sensitive investigatory method since it associated anatomical and functional aspects in data obtained, justifying its initial use for certain authors.

[Cholesteatoma of the posterior cerebral fossa. 7 cases and review of the literature]. / Cholestéatomes de la fosse cérébrale postérieure. Sept observations et revue de la littérature.

Fifty percent of intracranial epidermoid cysts are located in the cerebral posterior fossa. Clinical presenting features are not specific and vary according to cyst topography and mass effect on neighbouring structures. In CT, the lesion is hypodense as related to the cerebral tissue, but with no specificity. In MRI, the typical form shows quasi-pathognomonic morphologic characters with polyedric contours, a marble aspect, a reduced mass effect as compared to the tumor volume and an evolution signal close to that of cerebrospinal fluid, with no increase after contrast agent injection. Some primary cholesteatomas have a different radiological aspect. They can be hyperdense in CT and have a spontaneous hyperintense signal in T1-weighted MRI sequence. They correspond to complicated epidermoid cysts associated with hemorrhages and granulomatous meningeal reaction whose constitution is very very close to that of cholesterine granulomas.

[The empty delta sign. A useful or misleading sign in cerebral x-ray computed tomography?]. / Le "signe du delta vide". Un signe utile ou pervers en tomodensitométrie cérébrale?

One case of bifidity of the superior sagittal sinus, resulting in a false "empty delta sign", is presented. The authors emphasize the importance of the indirect signs of sinovenous thrombosis, i.e. cerebral edema and multiple or bilateral hemorrhagic infarcts, in the diagnosis of true empty delta sign.

[Relations between neurinoma of the VIII cranial nerve and the porus of the internal auditory meatus. Apropos of 110 cases]. / Rapports du neurinome du VIII avec le porus du conduit auditif interne (CAI). A propos de 110 cas.

110 cases of neurinomas of the VIIIth with APC extension (104 patients) were studied using MRI or CT. Classically, it is said that the tumoral mass is centered on the IAC. In our study, among 110 cases of neurinomas, only 9 were centered along the axis of IAC on axial slices and only 23 on coronal slices. The anterior development of the tumor is never more than 1 cm, except in 3 cases of large and multicystic neurinoma. We suggest that the anterior development of large tumors is limited by the VIIth nerve.

[Blue tympanic membrane. Apropos of 3 cases]. / Tympans bleus. A propos de trois observations.

A CT scan allowed simple diagnosis of the affection in three patients with the blue tympanic membrane syndrome. Lesions included prolapse of the internal jugular vein sinus into the tympanic cavity, an aberrant trajectory of the internal carotid artery in the middle ear and a tympano-jugular glomus tumor. Angiographic investigation of the latter lesion was performed more as a pre-treatment procedure rather than for diagnostic purposes, since it served as a guide to surgery, consisting usually of embolization.

[Disk highlighting after injection in MRI. Macroscopy and histology of 25 postoperative recurrences]. / Le rehaussement discal après injection en IRM. Macroscopie et histologie de 25 récidives post-opératoires.

400 cases of failed back syndrome were examined with MRI in a prospective study (SE w Rho and T2, SE wT1 before and after injection of paramagnetic contrast agent in axial and sagittal planes). After second time surgery, 70 cases of herniated disks were found. 25 herniated disks were studied in microscopy and results correlated with enhanced herniated disks. Authors describe 4 types of enhancement: veinous plexus (5/24), inflammatory or granulomatous tissue (12/24), degenerative disc with fibrosis (5/24) and osteophytosis (2/24). The criterions of each pattern are described.

[Hematomas and MRI at 0.15 T. Apropos of 100 cases]. / Hématomes et IRM à 0.15 T. A propos de 100 cas.

One hundred hematomas were examined by magnetic resonance imaging (MRI) at 0.15 T, all explored in SEpT1 and most in SEpT2. The number of cases examined in the acute phase during the first 48 hours was low: 8 cases. At this SEpT1 period the hematoma appears of elevated signal with good muscle contrast but without contrast in hepatic and cerebral parenchyma. In a weighted T2 sequence, the intense signals of cerebral edema and plasma or serum enables detection of the encephalic lesion. Findings from 68 hematomas observed in the subacute or chronic phase suggest that their appearance is pathognomonic with visualization in SEpT1 of a crown of an intense signal at least equal to that of fat. The only difficulty at this period is the discovery of a hematoma within the fat: orbital, retroperitoneal... The collection of a subdural hematoma usually appears homogeneous, the intensity of the signal varying with red cell concentration and time. In the soft tissues, the intensity of signal is a function of concentration of hemoglobin and its derivatives and of volume of serous effusion. Images of 24 hematomas during the sequelae phase confirmed the appearance of a "biochemical shell" without signal in SEpT2 and allowed detection of the hematic contents of an occupying process even after long periods, sometimes after one year.

[Inter-apophyseal articular synovial cyst of the lumbar spine. X-ray computed tomographic and magnetic resonance imaging correlation. Apropos of 2 cases]. / Kyste synovial articulaire inter-apophysaire du rachis lombaire confrontation tomodensitométrique et imagerie par résonance magnétique. A propos de 2 cas.

Two patients presenting with L5 radiculagia were investigated by CT scan imaging. The origin of the pain was determined with certitude as arising from intraspinal development of an interapophyseal synovial cyst. Examination of the two cases by MR imaging provided conflicting results: in one patient images obtained by MR were not contributive and the synovial cyst would probably have been missed while in the other patient images were specific and very sensitive for diagnosis of interapophyseal synovial lesions. Treatment was surgical in both cases.

[Delayed, triangular, hyperdense, computed x-ray tomography images of the renal parenchyma following iodide injection. Interpretation of transient renal ischemia?]. / Les images tomodensitométriques hyperdenses, triangulaires, retardées, du parenchyme rénal après injection d'iode. Traduction d'une ischémie rénale transitoire?

Three cases of renal ischemia diagnosed by Computed Tomography (CT) are presented. The pathophysiology of renal ischemia which accounts for the CT findings observer in these cases are reviewed. In the appropriate climate setting a diagnosis of renal ischemia may be made by CT, when a zone or zones of low attenuation after injection and enhancement of these same zones 6 to 72 hours later are observed in the kidney.

[Primary brain lymphoma in AIDS. 17 cases studied by MRI before stereotaxic biopsies]. / Lymphome cérébral primitif du SIDA. 17 cas explorés en IRM avant biopsie stéréotaxique.

AIM: Determining which semiological criteria might help to suggest lymphoma when an intracerebral mass in observed in a patient with AIDS. The use of these criteria might shorten the duration of the anti-toxoplasmic test treatment and to perform puncture earlier. The fast growth of the lymphomas may account for the rapid death of these patients if untreated, but as a corollary, its increase in size can be objectively measured over a short period, about ten days. MEANS: Retrospective study of 17 lymphomas diagnosed with stereotaxic puncture. RESULTS: The most discriminating criteria are ventricular encasement or an original site in the white matter, as well as the moderate character of the edema and of the mass effect relative to the volume of the tumor. Other arguments also help: simple lesion, large size, sinuous contour, no signs of hemorrhage. CONCLUSION: The diagnosis of lymphoma can often be proposed at once. A control must then be performed very soon, with stereotaxic puncture if the volume of the lesion has increased in the meantime.

[Metastasis in pulmonary arteries]. / Métastases néoplasiques intra-artérielles pulmonaires.

We report two cases of pulmonary tumor emboli. The first patient had a chondroblastic osteosarcoma of the pelvis while the second patient had a seminoma. The possibility of tumor emboli should be entertained in patients with prior history of malignancy presenting with enlargement of the pulmonary arteries and thrombus enhancement on delayed scans.

[MRI of the internal auditory meatus. Is injection of gadolinium indispensable?]. / IRM du méat auditif interne. L'injection de gadolinium est-elle indispensable?

OBJECT: To compare prospectively high resolution fast spin echo T2 weighted (FSE-T2W) images and gadolinium-enhanced spin echo T1 weighted images for diagnosis of pathology of the internal auditory meatus (IAM). PATIENTS AND METHODS: 114 patients underwent MR imaging at 1.5 T with the following protocol: axial images; whole brain FSE-T2W sequence (256 matrix); 2 sequences focused on IAM with high resolution FSE-T2W acquisitions (512 matrix, 3 mm sections with 1.5 mm overlapping); pre and postcontrast T1 weighted sequences focused on IAM. Examinations were viewed by senior neuroradiologists. RESULTS: 31 lesions were detected in the IAM by high resolution FSE-T2W images; 25 lesions were found in the IAM by postcontrast T1 weighted images, i.e. 6 false-positive results and none false-negative. On the basis of 228 studied IAMs the sensitivity, specificity and negative predictive value of this high resolution FSE-T2W sequence were 100%, 97% and 100% respectively. CONCLUSION: Gadolinium enhanced sequence is not indispensable if high resolution FSE-T2W images are normal. Gadolinium-enhanced sequence remains essential in others equivocal cases (difficult diagnosis or abnormal IAM).

[Value of investigation tests in thoracic goiters]. / Intérêt des examens complémentaires dans les goitres plongeants.

Two groups of substernal goiters should be considered fist; the "simples" ones localised in the anterior and superior part of the mediastin. They are most common and less dangerous. By opposition to the "complexes" ones which have relation with the vessels, the airways and the digestive tube. That surgeons would like to approach with security. The study of those retrosternal goiters requires two categories of complementary examinations. One for diagnosis: X Ray standard of the neck and the chest; Echography Biopsy and Radioactive Iodine scintigraphy. Others for localisations to prevent the risks, particularly vascular seeing in the surgery of the substernal goiters: TDM and IRM.