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Biomedical subjects

P Soyer

Publications and source records attributed to P Soyer.

At least 19 recordsLinked to original sources
PubMed1996

CT during arterial portography.

CT during arterial portography (CTAP) is based on portal enhancement of the liver by infusion of contrast material through the superior mesenteric or splenic artery. This technique provides high degrees of enhancement of the portal vein and intrahepatic vessels, allowing reliable segmental localisation of tumours and accurate assessment of relationships between tumours and intrahepatic vessels. Because of its invasiveness, CTAP must be limited to patients for whom non-invasive preoperative imaging suggests resectable tumour. In the majority of cases, CTAP is performed in patients with hepatic metastases from colorectal cancer, but other types of hepatic tumour (either primary or secondary) and pancreatic tumour may be an indication for CTAP. Visualisation of non-tumorous perfusion defects is a limitation of this technique, but such defects have been well described and have characteristic locations and appearance. In difficult cases, correlation with sonographic, CT and MRI findings helps characterise portal perfusion defects. CTAP is the most sensitive technique for the detection of intrahepatic tumours, and the recent use of spiral technology shows promise in the performance of CTAP. CTAP data can be viewed as multiplanar and three-dimensional reconstructions that allow preoperative planning of the extent of resection and determination of the volume of the remaining liver after resection.

Carcinoma, Hepatocellular↗
PubMed1996

Magnetic resonance imaging of the spleen: influence of the dose of a gadolinium chelate on the degree of parenchymal enhancement.

RATIONALE AND OBJECTIVES: We examined how the dose of an intravenous (i.v.) gadolinium chelate (gadoterate meglumine) would affect the degree of splenic enhancement on magnetic resonance (MR) imaging. METHODS: Forty patients had breath-hold three-dimensional fast spoiled gradient-recalled MR imaging of the abdomen done before and after i.v. administration of one of four doses of gadoterate meglumine (0.075, 0.100, 0.150, or 0.200 mmol/kg). Peak enhancement values and the time to peak enhancement of splenic parenchyma were compared (values are reported as means +/- standard deviations). RESULTS: Peak enhancement values were 154 +/- 99%, 215 +/- 109%, 276 +/- 170%, and 349 +/- 144 +/- for the doses of 0.075, 0.100, 0.150, and 0.200 mmol/kg, respectively. A high correlation was found between the dose and mean peak enhancement values (R2 = .998), which varied as a linear function of the dose. The mean times to peak enhancement obtained with the four doses were not significantly different. CONCLUSION: Using doses ranging from 0.075 to 0.200 mmol/kg, the peak enhancement of splenic parenchyma is a linear function of the dose of the gadolinium chelate administered. The time to peak splenic enhancement is not affected.

Adult↗
PubMed1996

Dynamic contrast-enhanced subtraction versus T2-weighted spin-echo MR imaging in the follow-up of colorectal neoplasm: a prospective study of 41 patients.

PURPOSE: To compare dynamic contrast-enhanced subtraction (DCES) and T2-weighted spin-echo (SE) magnetic resonance (MR) imaging in the differentiation of fibrosis from recurrence during the follow-up of treated colorectal neoplasms. MATERIALS AND METHODS: Forty-one patients with 39 malignant and 16 benign lesions confirmed by means of surgery (n = 23), biopsy (n = 24), or 12-month follow-up examination (n = 8) underwent DCES MR imaging and T2-weighted SE MR imaging. Enhancement of an abnormal pelvic structure within the first 90 seconds on DCES images or high signal intensity on T2-weighted SE images was considered indicative of malignancy. RESULTS: Sensitivity, specificity, and positive and negative predictive values were, respectively, 97%, 81%, 93%, and 100% for DCES MR imaging and 77%, 56%, 81%, and 56% for T2-weighted MR imaging. The number of correctly classified lesions was significantly higher with DCES imaging compared with T2-weighted imaging (P < or = .006). CONCLUSION: DCES imaging is more accurate than T2-weighted SE imaging for differentiating fibrosis from recurrence during the follow-up of treated colorectal neoplasms.

Colon↗
PubMed1996

Transitional cell carcinoma of the renal pelvis: a retrospective look at CT staging with pathologic correlation.

PURPOSE: To identify the reasons for the discrepancies between computed tomographic (CT) and pathologic staging of transitional cell carcinoma of the renal pelvis and to develop new criteria to increase the accuracy of CT in staging. MATERIALS AND METHODS: CT scans of 31 consecutive patients with renal pelvic transitional cell carcinoma were evaluated. CT and pathologic staging were compared. RESULTS: Pathologic staging revealed four stage 0 tumors, three stage I, five stage II, 10 stage III, and nine stage IV. The initial overall CT staging accuracy was 52% (16 of 31 patients). The sensitivity for minimal invasion was 17% (two of 12 patients). Two-thirds (10 of 15 patients) of the misinterpreted cases were overstaged as stage III. Proximal hydronephrosis was present in 80% of overstaged cases (eight of 10 patients). Reevaluation of the CT studies by using proximal hydronephrosis as a criterion for minimal invasion improved overall CT staging accuracy (77%). The revised staging yielded a sensitivity of 83% and specificity of 95% for minimal invasion and improved the specificity for deep invasion (17% to 92%). CONCLUSION: In a patient with transitional cell carcinoma of the renal pelvis, hydronephrosis proximal to the tumor may cause overstaging of stage 0-II disease and may not indicate more advanced disease.

Carcinoma in Situ↗
PubMed1996

Assessment of right ventricle function and pulmonary artery circulation by cine-MRI in patients with AIDS.

OBJECTIVE: To evaluate right ventricle (RV) anatomy and performance and its relationships with pulmonary circulation in AIDS patients. DESIGN: We conducted a prospective blinded study by using cine-MRI, a well-accepted method to assess RV and pulmonary circulation. SETTING: A university hospital. PARTICIPANTS: Ten healthy volunteers and 13 asymptomatic AIDS patients. MEASUREMENTS: RV end-diastolic and end-systolic volumes, RV ejection fraction (RVEF), pulmonary artery (PA) diameter, main pulmonary artery distensibility (MPAD), RV free wall diastolic thickness (RVWT), and RV mass were measured. The RVWT/left ventricular wall thickness index was calculated. RESULTS: AIDS patients had significantly increased RV end-diastolic and end-systolic volumes and decreased RVEF (50 +/- 10 vs 59 +/- 6; p < 0.03). Four AIDS patients had RV wall motion abnormalities; 5 (38%) had an RVEF under 45%. RVWT, the RVWT/left ventricular wall thickness index, and PA diameter were significantly increased in AIDS patients. RV mass was increased in 54% of AIDS patients. MPAD was significantly lower in AIDS patients (18.8 +/- 15 vs 26 +/- 4; p < 0.01). A significant relationship was found between RV mass and MPAD (r = 0.76; p = 0.02). CONCLUSIONS: RV function is frequently impaired in AIDS patients. Anatomic and functional abnormalities found in RV and PA parameters suggest a systolic overload on RV. Pulmonary circulation abnormalities may influence RV structure and function in AIDS patients.

Acquired Immunodeficiency Syndrome↗
PubMed1996

T2-weighted spin-echo MR imaging of the liver: breath-hold fast spin-echo versus non-breath-hold fast spin-echo images with and without fat suppression.

OBJECTIVE: The goal of our study was to compare a T2-weighted breath-hold fast spin-echo (BHSE) technique with T2-weighted non-breath-hold fast spin-echo techniques for imaging the liver. SUBJECTS AND METHODS: Thirty-three patients with hepatic lesions had T2-weighted BHSE images obtained in 22 sec and conventional T2-weighted non-breath-hold fast spin-echo images obtained in 3 min 12 sec with and without fat suppression. Images were analyzed quantitatively by measuring the lesion-liver contrast, spleen-liver contrast, and signal-to-noise ratios of lesions and qualitatively by evaluating the sharpness of hepatic contours, visibility of intrahepatic vessels and other segmental landmarks, and presence of artifacts. RESULTS: Quantitatively, lesion-liver contrast, spleen-liver contrast, and signal-to-noise ratios obtained with the BHSE technique were inferior to those obtained with fast spin-echo techniques with and without fat suppression (11.2 +/- 7.1 versus 15.4 +/- 10.6 and 14.5 +/- 9.8, p < .001; 5.3 +/- 3.7 versus 8.7 +/- 3.5 and 7.0 +/- 3.8, p < .001; 16.2 +/- 8.2 versus 20.1 +/- 10.9 and 19.7 +/- 9.5, p < .01, respectively; Student's t test). Qualitatively, image artifacts and intrahepatic vessel depiction on BHSE images were similar to those obtained with the fast spin-echo techniques. The BHSE technique was superior to fat-suppressed fast spin-echo technique for showing hepatic contours (p < .01; Wilcoxon signed-rank test). CONCLUSION: The BHSE technique is quantitatively inferior to non-breath-hold fast spin-echo techniques. However, further studies with a surgical standard of reference are needed to compare the three techniques in terms of sensitivity.

Adipose Tissue↗
PubMed1996

Detection of focal hepatic lesions with MR imaging: prospective comparison of T2-weighted fast spin-echo with and without fat suppression, T2-weighted breath-hold fast spin-echo, and gadolinium chelate-enhanced 3D gradient-recalled imaging.

OBJECTIVE: The purpose of this study was to compare breath-hold three-dimensional (3D) rapid gradient-echo (GRE) MR imaging obtained before and after gadolinium chelate injection with T2-weighted fast spin-echo and T2-weighted breath-hold fast spin-echo (BHFSE) MR imaging in the detection of focal hepatic masses. SUBJECTS AND METHODS: Fifty-three patients with 108 focal hepatic masses had, prospectively, MR of the liver at 1.5 T. T2-weighted fast spin-echo (6000/117 [TR/effective TE]; echo train length=16; acquisition time = 3 min 12 sec) images obtained with and without fat suppression, T2-weighted BHFSE (2700/105; echo train length = 20; acquisition time = 22 sec), and 3D rapid GRE images (10.1/1.9/30 degrees [TR/TE/alpha]) obtained during one breath-hold (12 scan locations in 21 sec or 20 scan locations in 32 sec) before and after injection of gadolinium chelate were blindly and independently analyzed in consensus by three readers. RESULTS: Gadolinium chelate-enhanced 3D rapid GRE images allowed depiction of more focal hepatic masses (90 of 108, sensitivity = 83%) than did T2-weighted fast spin-echo with fat suppression images (76 of 108, sensitivity = 70%), T2-weighted fast spin-echo without fat suppression images (74 of 108, sensitivity = 69%), T2-weighted BHFSE images (73 of 108, sensitivity = 68%), and unenhanced 3D rapid GRE images (54 of 108, sensitivity = 50%) (p < .01). No difference in sensitivity was found between the three T2-weighted sequences. CONCLUSION: Gadolinium chelate-enhanced 3D rapid GRE imaging is superior to T2-weighted fast spin-echo images obtained with or without fat suppression for the detection of focal hepatic masses. T2-weighted BHFSE is similar to T2-weighted fast spin-echo images in detecting focal hepatic lesions.

Adult↗
PubMed1996

[Bronchial anastomotic complications after pulmonary transplantation. X-ray computed tomographic evaluation].

PURPOSE: To determine the sensitivity and specificity of CT in depicting bronchial anastomotic complications after lung transplantation. MATERIALS AND METHODS: A retrospective, blinded review of 105 CT scans obtained after single (n = 17) or double (n = 10) lung transplantation in 27 patients was done by two radiologists in consensus. CT images, were analyzed with respect to the status of bronchial anastomoses, with three possible answers given to the readers: normal, dehiscence, or stenosis. CT features were correlated to bronchoscopic and follow-up findings, which were considered as standard of reference. RESULTS: CT had a 60% sensitivity and 98% specificity for the diagnosis of bronchial dehiscence, and 40% and 99% for the diagnosis of anastomotic stenosis. One case of bronchial disruption was diagnosed on CT scan only and subsequently confirmed by repeated bronchoscopy. CONCLUSION: In our study, CT has a low sensitivity but a high specificity in the detection of bronchial anastomotic complications after lung transplantation. However, CT remains useful in some cases, as it can show complications not seen bronchoscopically.

Adult↗
PubMed1995

Hepatic leiomyosarcomas: CT features with pathologic correlation.

The purpose of this study was to determine the computed tomographic (CT) features of hepatic leiomyosarcoma and to correlate them with pathologic findings. CT examinations of 15 patients with pathologically proven leiomyosarcoma of the liver were retrospectively reviewed. Three patients had primary leiomyosarcoma of the liver and 12 patients had 43 distinct hepatic metastases originating from a primary gastrointestinal (n = 8), uterine (n = 2) or retroperitoneal (n = 2) leiomyosarcoma. In the 11 patients who had partial hepatic resection or surgical biopsy of their tumors, a correlation was made between CT imaging and pathologic findings. Primary leiomyosarcomas showed heterogeneous enhancement; two displayed internal and peripheral enhancement, and one showed peripheral enhancement with a pseudocystic pattern (i.e. enhancing thick wall with internal nonenhancing low attenuation area). Leiomyosarcomas metastatic to the liver were homogeneous, showing no or moderate enhancement (10 of 43 metastases, 23%) or heterogeneous and predominantly peripheral enhancement (33 of 43 metastases, 77%). A pseudocystic pattern was seen in 13 of the 43 metastases (30%). Homogeneous tumors were made of smooth fibrous-like tissue without area of necrosis. Heterogeneous tumors contained varying degrees of necrosis and hemorrhage or gelatinous tissue. We found that primary and secondary hepatic leiomyosarcomas of the liver can exhibit different features. A pseudocystic pattern is uncommon. Furthermore, purely cystic tumors were not seen in our series.

Adult↗
PubMed1995

Abdominal aortic aneurysms: assessment with gadolinium-enhanced time-of-flight coronal MR angiography (MRA).

A prospective study was performed to evaluate the efficacy of a gadolinium-chelate-enhanced MR angiography (MRA) using a coronal acquisition in the preoperative assessment of aneurysms of the abdominal aorta (AAA). Twenty patients with AAA were explored with MR using a two-dimensional (2D) time-of-flight MRA technique with a coronal acquisition, before and after intravenous administration of 0.1 mmol/kg of a gadolinium-chelate. Gadolinium-chelate-enhanced MRA with a coronal acquisition decreased deleterious saturation effects within aorta and iliac arteries in 16 of 20 patients (80%) and improved the overall quality of the images of the upper and lower parts of the AAA (i.e. extent of the aneurysm). Furthermore, gadolinium-chelate-enhanced MRA with a coronal acquisition allowed a better differentiation between slow flow and mural thrombus. Gadolinium-chelate-enhanced MRA had a sensitivity of 100% and a specificity of 96% for evaluation of renal artery involvement, and a sensitivity of 93% and a specificity of 100% for iliac artery involvement. The results of this study show that gadolinium-chelate-enhanced MRA obtained with a coronal acquisition is efficacious for the preoperative assessment of AAA.

Aorta, Abdominal↗
PubMed1995

Assessment of vascular involvement with magnetic resonance angiography (MRA) in Pancoast syndrome.

The purpose of this study was to evaluate the diagnostic value of MRA in determining vascular involvement in bronchogenic carcinoma with Pancoast syndrome. Six patients with Pancoast syndrome were investigated preoperatively by means of MRA. Following standard spin-echo MR imaging in the axial and coronal planes, two successive two-dimensional (2D) time-of-flight acquisitions were obtained in the axial plane, the first with venous, the second with arterial presaturation. MRA data were compared to angiographic data in four cases, and to surgical findings in all six cases. MRA demonstrated displacement (n = 2) and encasement (n = 2) of subclavian and/or brachiocephalic arteries, and encasement or occlusion of subclavian and/or right brachiocephalic vein (n = 3). Close correlation between MRA, angiography and surgery was obtained. These preliminary results suggest that MRA is a noninvasive diagnostic method complementary to MR imaging for detecting vascular involvement in bronchogenic carcinoma with Pancoast syndrome.

Adult↗
PubMed1995

Haemoperitoneum due to spontaneous rupture of hepatic haemangiomatosis: treatment by superselective arterial embolization and partial hepatectomy.

A case is reported of a 36-year-old woman with haemoperitoneum due to spontaneous rupture of hepatic haemangiomatosis. Computed tomography showed a subcapsular hepatic mass in the posterior segment of the right hemiliver (subsegment 7) containing a fluid-fluid level. Magnetic resonance imaging depicted a subcapsular hepatic mass displaying an internal fluid-fluid level suggestive of haematoma. Hepatic angiography showed an intense arterial blush in the area of the subsegment 7 and permitted a subsequent and temporarily effective superselective transcatheter embolization of the subsegmental arterial branch for subsegment 7. Because of a recurrence of intraperitoneal haemorrhage 15 days after the first embolization, a new selective hepatic artery embolization was performed. However, intraperitoneal haemorrhage recurred 10 days after the second embolization, and the patient underwent resection of the posterior segments of the right hemiliver (subsegments 6 and 7). This case suggests that superselective arterial embolization, when used alone, does not provide a permanent treatment of haemoperitoneum due to spontaneous rupture of hepatic haemangiomatosis. However, this technique seems to be useful in avoiding an emergency surgery, allowing a planned hepatic resection.

Adult↗
PubMed1995

Thoracic aortic dissection: diagnosis with transesophageal echocardiography versus MR imaging.

PURPOSE: To compare transesophageal echocardiography (TEE) and magnetic resonance (MR) imaging in the diagnosis of dissection of the thoracic aorta. MATERIALS AND METHODS: Thirty-one consecutive patients with clinically suspected aortic dissection and 10 postoperative patients underwent transesophageal color Doppler echocardiography and MR imaging. Imaging results were compared at independent double-blind readings. Final diagnosis was obtained from consensual review of all corroborative studies. RESULTS: MR imaging depicted the intimal flap in 95% of aortic dissections; TEE, in 86% (P < .05). In surgical patients, the sensitivity of MR in detection of residual dissection was 100% versus 86% with TEE (P < .05). The inferior extent of the dissected lumen was seen only with MR imaging. False-positive results occurred in two cases with TEE and in one with MR imaging. CONCLUSION: MR imaging is superior to TEE in the evaluation and follow-up of dissection of the thoracic aorta. Because the availability of MR is limited, however, TEE should remain the standard modality for diagnosis.

Adult↗
PubMed1995

Potentially resectable pancreatic adenocarcinoma: spiral CT assessment with surgical and pathologic correlation.

PURPOSE: To evaluate the accuracy of spiral computed tomography (CT) in assessing the resectability of small pancreatic ductal adenocarcinoma and to correlate the CT findings with histopathologic and surgical findings. MATERIALS AND METHODS: Spiral CT scans obtained in 64 patients who underwent surgery for potentially resectable pancreatic adenocarcinoma were prospectively assessed for tumor resectability. CT findings were correlated with surgically assessed extent of tumor and pathologic findings. RESULTS: Fifty-seven (89%) of 64 carcinomas were detected with spiral CT. Twenty-four carcinomas were resectable at surgery and 40 were not. The average size of resectable tumors was 3.1 cm (range, 1.0-7.5 cm). The overall accuracy of spiral CT for assessing resectability was 70%. Of resected tumors, 14 were hypoattenuating compared with the remaining pancreas and 10 were isoattenuating. Eleven tumors showed neointimal proliferation in arterioles at histologic examination. CONCLUSION: Further progress in preoperative staging of pancreatic ductal adenocarcinoma with spiral CT should be directed toward improving detection of small pancreatic tumors and assessment of early metastatic disease.

Adenocarcinoma↗
PubMed1995

Variations in the intrahepatic portions of the hepatic and portal veins: findings on helical CT scans during arterial portography.

OBJECTIVE: The goals of this study were to describe variations in the intrahepatic portions of the hepatic and portal veins as visualized by helical CT during arterial portography (CTAP) and to examine the surgical implications of these findings. MATERIALS AND METHODS: A retrospective review of 69 helical CTAP scans of 69 patients with small hepatic tumors and no evidence of vascular invasion or distortion was done. Axial helical CTAP scans were reviewed to determine the presence, number, and location of intrahepatic portions of the hepatic and portal veins. RESULTS: Among the 60 patients (87%) in whom the right, middle, and left hepatic veins were visualized, 19 (32%) had supernumerary hepatic veins. Right inferior hepatic veins were found in six (9%) of the 69 patients. Variations in intrahepatic portal anatomy were found in four patients (6%) and involved an immediate trifurcation of the portal vein in three patients (4%) and a left main portal vein originating from the right anterior portal branch in one patient (2%). CONCLUSION: Variations in the intrahepatic portions of the hepatic and portal veins are frequently seen on helical CTAP scans. Recognition of such variations is important in the preoperative evaluation of patients with hepatic tumors because these variations may have implications for tumor resection and for planning the operative approach.

Adult↗
PubMed1995

Splenic involvement in pancreatitis: spectrum of CT findings.

The pancreas is located deep within the retroperitoneum in the anterior pararenal space. The distal portion of the pancreatic tail extends along the course of the splenic artery and vein (Fig. 1) and enters the splenic hilum contained within the splenorenal ligament. Because of these anatomic relationships, the spleen and splenic vessels may be involved by pancreatitis. Although rare (frequency, 1-5%), splenic involvement by pancreatitis includes intrasplenic pseudocyst, abscess, hemorrhage, infarction, splenic rupture, and vascular injury. Because these complications can be life-threatening, the extent and course of the disease are closely monitored with CT to determine whether and when aggressive intervention is necessary to avoid catastrophic clinical outcomes. The purpose of this essay is to illustrate the spectrum of CT findings in cases of pancreatitis with splenic involvement.

Humans↗
PubMed1995

Nontumorous low-attenuation defects in the liver on helical CT during arterial portography: frequency, location, and appearance.

OBJECTIVE: Low-attenuation defects in the liver that are caused by variations in the portal perfusion of the liver rather than by intrahepatic tumor can be detected using helical CT during arterial portography (CTAP). The purpose of this study was to characterize these nontumorous low-attenuation defects detected with helical CTAP in terms of their frequency, location, and appearance. MATERIALS AND METHODS: Helical CTAP examinations of 89 patients referred for preoperative evaluation of metastatic or primary liver tumors performed over a 20-month period were retrospectively reviewed by three radiologists. The frequency, appearance, and location of focal (within a subsegment) and diffuse (affecting more than one subsegment) nontumorous perfusion defects were determined. Findings on helical CTAP images were correlated with surgical findings (53 patients), results of MR examinations (25 patients), and follow-up CT examinations (11 patients). RESULTS: Ninety-seven nontumorous perfusion defects were identified in 68 patients. The most frequent defects were located adjacent to the gallbladder fossa (35), anterior to the porta hepatis (34), in the subcapsular portion of the liver (13), and adjacent to the falciform ligament (12). Nontumorous perfusion defects characteristically appeared wedge-shaped or flat and ranged in size from 8-20 mm. CONCLUSION: Nontumorous perfusion abnormalities have characteristic appearances and locations on helical CTAP examinations and are more common than previously reported with conventional CTAP. Familiarity with the locations and characteristic appearances of these defects is essential to prevent false-positive diagnoses, so that operative candidates are not mistakenly denied surgical therapy.

Adult↗