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L Monnier-Cholley

Publications and source records attributed to L Monnier-Cholley.

At least 37 records · Page 2Linked to original sources
PubMed1997

Classification of normal and abnormal lungs with interstitial diseases by rule-based method and artificial neural networks.

We devised an automated classification scheme by using the rule-based method plus artificial neural networks (ANN) for distinction between normal and abnormal lungs with interstitial disease in digital chest radiographs. Four measures used in the classification scheme are determined from the texture and geometric-pattern feature analyses. The rms variation and the first moment of the power spectrum of lung patterns are determined as measures for the texture analysis. In addition, the total area of nodular opacities and the total length of linear opacities are determined as measures for the geometric-pattern feature analysis. In our classification scheme with these measures, we identify obviously normal and abnormal cases first by the rule-based method and then ANN is applied for the remaining difficult cases. The rule-based plus ANN method provided a sensitivity of 0.926 at the specificity of 0.900, which was considerably improved compared to performance of either the rule-based method alone or ANNs alone.

Diagnosis, Computer-Assisted↗
PubMed1997

[Imaging of a case of wirsungorrhagia].

We report a case of wirsungorrhagia related to rupture of a pseudoaneurysm into the duct of Wirsung in a patient with chronic pancreatitis. Upper gastrointestinal endoscopy showed blood coming from the papilla of Vater suggesting wirsungorrhagia. Non-contrast computed tomography showed a spontaneous hyperdensity and arteriography showed an extravasation of contrast within a very large duct of Wirsung confirming wirsungorrhagia. Arteriography and dynamic computed tomography revealed a pseudoaneurysm from the left gastric artery. The pseudoaneurysm was successfully embolized with four steel microcoils, after super-selective catheterization of small branch of the left gastric artery, keeping gastric and liver vascularization.

Aneurysm, False↗
PubMed1996

Quantitative analysis of geometric-pattern features of interstitial infiltrates in digital chest radiographs: preliminary results.

We are developing a computerized method for detection and characterization of interstitial diseases based on a quantitative analysis of geometric features of various infiltrate patterns in digital chest radiographs. In our approach, regions of interest (ROIs) with 128 x 128 matrix size (22.4 mm x 22.4 mm) are automatically selected, covering peripheral lung regions. Next, nodular and linear opacities, which are the basic components of interstitial infiltrates, are identified from two processed images obtained by use of a multiple-level thresholding technique and a line enhancement filter, respectively. Finally, the total area of nodular opacities and the total length of linear opacities in each ROI are determined as measures of geometric pattern features. We have applied this computer analysis to 72 ROIs with normal and abnormal patterns that were classified in advance by six chest radiologists. Preliminary results indicate that the distribution of measures of geometric-pattern features correlate well with radiologists' classification. These early results are encouraging, and further evaluation hopes to establish that this computerized method might prove useful to radiologists in their assessment of interstitial diseases.

Humans↗
PubMed1996

[Spontaneous pulmonary hernia and Recklinghausen disease].

The pulmonary hernia is a rare entity defined by protrusion of pulmonary tissue through an abnormal weakness of the thoracic wall. We describe a case of spontaneous pulmonary hernia associated with osseous sternocostal abnormalities in a patient with a Recklinghausen disease.

Female↗
PubMed1996

[Non-vascular retroperitoneal emergencies].

Acute renal disease, in the absence of trauma, consist of acute renal obstruction, renal infection or a combination of the two. The diagnosis of acute renal colic is usually performed with ultrasound or excretory urography whereas parenchymal involvement in renal infection is best demonstrated on computed tomography images. The aim of radiologic investigations is to look for complications in order to guide the treatment, particularly percutaneous procedures. Other less common acute renal diseases include renal vein thrombosis optimally analyzed with contrast injection to demonstrate renal function, and spontaneous renal hemorrhage, which implies careful renal assessment looking for a small tumor. Acute psoas compartment diseases include hematomas and abscesses. Computed tomography is the best diagnostic tool and the examination of choice for the follow-up lesions and to guide percutaneous drainage.

Acute Disease↗
PubMed1996

[Retroperitoneal vascular emergencies].

Ruptured abdominal aortic aneurysm is the major surgical emergency in the retroperitoneal compartment. Rupture of an abdominal aortic aneurysm is always fatal without urgent operative repair. Computed tomography is the reference standard for the diagnosis of ruptured abdominal aortic aneurysm in hemodynamically stable patients. At CT, the diagnosis is based on the combination of abdominal aortic aneurysm and extraluminal retroperitoneal blood. Retroperitoneal hemorrhage usually demonstrates both isodense and hyperdense areas. In most cases hemorrhage is located in psoas compartments and perirenal space. In the case of ruptured abdominal aortic aneurysm other findings may be demonstrated such as focal interruption of the aortic wall and active extravasation of contrast media in the retroperitoneal compartments. Inflammatory abdominal aortic aneurysm, that may present as acute abdominal pain, should be recognized and differentiated from ruptured abdominal aortic aneurysm. Inflammatory abdominal aortic aneurysm is characterized by a fibrotic process around the abdominal aorta that may entrap adjacent structures such as ureters, duodenum and inferior vena cava. Aortic dissection, mycotic aneurysm, and inferior vena cava thrombosis are less common. Complications occurring after emergency aneurysm replacement are also considered.

Adult↗
PubMed1996

[Interventional radiology and abdominal emergencies].

Interventional radiology used in acute abdominal diseases has demonstrated its efficacy in most emergency cases especially in patients at high risk for surgery. Percutaneous drainage is a reference standard for abscesses located within the abdomen and pelvis with high success rates of up to 80%. The diagnosis and treatment of gastrointestinal hemorrhage have changed over the past two decades, with decreased diagnostic examinations and advances in pharmacologic therapy and improved endoscopic techniques. On the other hand, embolization techniques and new procedures such as trans jugular intra hepatic porto systemic shunt have been developed. Arterial embolisation in many situations such as blunt or direct trauma, obstetric or post operative hemorrhage, can be used as an effective easy and relatively safe technique with high success rates to stop bleeding and save the organ. Percutaneous drainage and angiographic techniques adapted to biliary and urinary tree have also been developed as well as endoscopic procedures, allowing treatment of stenoses by balloon dilatation, or plastic or metal prostheses. Indications, technical aspects, complications and limits of these various procedures are presented.

Abdomen, Acute↗
PubMed1996

[Abdominal emergencies of infectious origin].

Infectious disease is a common cause of acute abdomen. The diagnosis is based on clinical examination and basic laboratory tests. However, medical imaging routinely performed according to the clinical findings is frequently useful. Hepatic and splenic abscesses are correctly demonstrated by ultrasonography and computed tomography. Ultrasonography is the reference standard for the diagnosis of acute cholecystitis. The US examination is also performed for the diagnosis of appendicitis and its complications. Ultrasonography and barium enerna are commonly performed for the evaluation of signoid diverticulitis. Computed tomography is the reference standard to determine medical or surgical procedures.

Abdomen, Acute↗
PubMed1996

[Abdominal injuries].

Radiologic evaluation of abdominal trauma must provide a quick and accurate assessment of the lesions in order to improve the management of the patient. The technique used varies depending on the mechanism of the trauma (blunt trauma or stab wounds) and the hemodynamic status. Radiologic evaluation is usually performed in blunt trauma whereas stab wound trauma is usually explored surgically. The various techniques available are standard radiographs, ultrasonography, computed tomography and arteriography. The role of magnetic resonance imaging in the immediate evaluation is still not well defined. It appears to be a useful method in the delayed evaluation of diaphragmatic trauma. Computed tomography is the method most commonly performed in trauma patients. This technique is accurate and allows correct assessment of the lesions. The disadvantages are the radiation induced and the need for a hemodynamically stable patient. The aim of the radiologic evaluation is to provide the clinicians with an accurate description of the lesions. It can help in the management of the patient usually in association with clinical and laboratory data. It can also guide interventional procedures (drainage, embolization...). Finally, it allows radiographic follow-up when conservative treatment is performed.

Abdominal Injuries↗
PubMed1996

[Imaging of primary hepatic pheochromocytoma].

Extra-adrenal pheochromocytoma are extremely uncommon tumors. They demonstrate abdominal (97% of the cases), thoracic, vesical or cervical localizations. We report the case of a hepatic pheochromocytoma in a young patient with a post history of labile arterial hypertension. Ultrasonography, computed tomography and magnetic resonance imaging features were similar to those of adrenal pheochromocytoma. The presence of neuroendocrine cells was supported by immunohistochemical criteria. Histological observation showed a lack of local extension. In addition, four years after surgery, there was no apparent clinical syndrome suggesting tumor recurrence or metastasis occurrence. These observations supports the diagnosis of non malignant, primary hepatic pheochromocytoma. To our knowledge, this is the first radiologic description of this kind of tumor.

Adult↗
PubMed1996

[Imaging of peritoneal mesotheliomas].

Peritoneal mesothelioma is a rare, either benign or malignant tumor of the peritoneum. We retrospectively analyzed the imaging features of six malignant and three benign peritoneal mesothelioma. Asbestos exposure was proven in three of the six malignant cases and in none of the three benign cases. Ascites was found in seven patients (78%), peritoneal masses in eight patients (88%), small peritoneal nodules in six patients (66%), parietal peritoneal thickening in six patients (66%), thickened mesentery in five patients (55%) and pleural plaques as well as nodules in one patient. These imaging features support the diagnosis of peritoneal mesothelioma but do not allow differentiation between benign and malignant forms of peritoneal mesothelioma.

Adult↗
PubMed1996

[Thrombosis of the renal vein and hemorrhagic rectocolitis].

Renal vein thrombosis was observed in a patient with acute ulcerative colitis complicated by retroperitoneal perforation. Retroperitoneal inflammation related to colonic perforation may constitute a predisposing factor for local thrombosis in combination with coagulation disorders (protein S deficiency).

Adult↗
PubMed1996

[Imaging of symptomatic giant hemangioma].

A case of symptomatic giant hemangioma of the liver with fever, anemia, and increased erythrocyte sedimentation rate is reported. Spontaneous hyperdense areas at CT, and high signal-intensity areas at T1-weighted MR images were demonstrated within the hemangioma. Marked hemorrhagic zones demonstrated at pathologic examination may explain these uncommon clinical and imaging features.

Adult↗
PubMed1995

Computerized analysis of interstitial infiltrates on chest radiographs: a new scheme based on geometric pattern features and Fourier analysis.

RATIONALE AND OBJECTIVES: Detection of interstitial infiltrates on chest radiographs is difficult and subjective. Therefore, we developed a computerized method to provide quantitative analysis of lung texture to increase diagnostic accuracy. METHODS: Two hundred chest radiographs--100 healthy and 100 abnormal with interstitial infiltrates--were digitized using a laser scanner. They were analyzed by an automated computerized scheme that uses a combination of two methods for detection of interstitial infiltrates: a lung texture analysis based on the Fourier transform and a geometric pattern feature analysis based on filtering techniques. RESULTS: The overall sensitivity and specificity of the computerized scheme were 92% and 90%, respectively. The scheme achieved a sensitivity of 80% in subtle cases (n = 15) and 88% in cases with localized interstitial disease (n = 26), whereas the specificity remained unchanged. There was good correlation between the computer output and the radiologists' severity rating. CONCLUSION: This enhanced computerized scheme exhibits high sensitivity and specificity with a large database.

Adolescent↗
PubMed1995

Computer-aided diagnosis for interstitial infiltrates in chest radiographs: optical-density dependence of texture measures.

We have been developing a computerized scheme for automated detection and characterization of interstitial infiltrates based on the Fourier transform of lung texture. To improve the performance of the scheme, which was developed using digitized screen-film radiographs, optical-density dependence of both the gradient of the film used and the system noise associated with the laser scanner were investigated. Two hundred chest radiographs, including 100 abnormal cases with interstitial infiltrates, were digitized using a laser scanner. The root-mean-square (RMS) variations and the first moments of the power spectra, which correspond to the magnitude and coarseness of lung texture, were determined by Fourier transform of lung textures in numerous regions of interest (ROIs). The RMS variation was dependent upon the average optical density in the ROI, though no obvious trend existed for the first moment of the power spectrum. Dependence of the RMS variations on optical density was corrected for using the gradient curve of the film. Also, system noise associated with the laser scanner was corrected. Results indicated that the specificity was improved from 81% (without correction) to 89% (with corrections), without any loss of sensitivity (90%). Thus, the correspondence between the computer output and consensus interpretation of radiologists was improved with the new scheme compared to the previous one. This improved computerized scheme may be useful to radiologists in detecting interstitial infiltrates in chest radiographs.

Automation↗
PubMed1995

Computerized detection of clustered microcalcifications: evaluation of performance on mammograms from multiple centers.

To investigate the performance of a computerized method for the automated detection of clustered microcalcifications in digitized mammograms from a variety of screening centers, the authors invited 118 radiologists to bring up to five mammograms to their scientific exhibit at the 1993 meeting of the Radiological Society of North America (RSNA). Forty-three mammograms from 14 sites were brought to the exhibit, where they were digitized and analyzed. Results of the analysis on the RSNA cases were compared with those obtained on a standard database of 39 mammograms collected from two centers. The performance of the detection algorithm on the RSNA images was lower than that achieved on the standard database. This lower performance was due in part to the higher fraction of very subtle clustered microcalcifications in the RSNA cases, as well as the apparent dependence of the algorithm on image characteristics (eg, contrast and noise), which varied from center to center. The authors conclude that the algorithm is robust and accurate enough to undergo clinical testing. When it is implemented clinically, the computerized scheme must be customized to the image characteristics at each specific screening center to obtain optimal performance.

Breast Diseases↗