Search PubMed⌕ Search

Biomedical subjects

P Soyer

Publications and source records attributed to P Soyer.

At least 91 records · Page 5Linked to original sources
PubMed1995

Imaging of intrahepatic cholangiocarcinoma: 2. Hilar cholangiocarcinoma.

Hilar cholangiocarcinoma (also called Klatskin's tumor) is more common than peripheral cholangiocarcinoma. Sonography, CT, MR imaging, angiography, and cholangiography can suggest the diagnosis, but the major issue of imaging with this tumor is to determine whether the tumor is resectable. The anatomic location of hilar cholangiocarcinoma makes resection difficult, so that surgical exploration of patients with this condition should be undertaken only when preoperative evaluation has shown a potential for curative resection. Preoperative assessment of resectability of hilar cholangiocarcinoma is often extensive, requiring several types of imaging. This pictorial essay reviews the imaging features of hilar cholangiocarcinoma. The role of imaging in the preoperative planning, with specific emphasis on staging extent of disease, including hepatic and vascular involvement, is discussed and illustrated.

Adult↗
PubMed1995

Helical (spiral) CT of the liver.

Helical (spiral) CT of the liver consistently results in high quality scans as a result of the ability to image the liver in a single breath hold. Lesion detection is aided by scanning during the peak of hepatic enhancement, by the lack of respiratory misregistration, and by obtaining overlapping axial reconstructions. Because of these advantages, helical (spiral) CT is the preferred scanning mode for evaluation of hepatic disease.

Contrast Media↗
PubMed1995

[Hepatic angiomyolipoma. Magnetic resonance imaging and imaging by CT-xray].

A case, is reported of a 40 year-old woman with a "form fruste" of tuberous sclerosis, multiple angiomyolipomas of the kidney, and an angiomyolipoma of the liver. On magnetic resonance imaging the hepatic mass was markedly hyperintense to liver on short TR/short TE spin-echo sequence. Spiral computed tomography during arterial portography showed hepatic mass in the right hemiliver with areas of negative attenuation values suggesting fat content. Pathologic examination of the resected specimen confirmed the diagnosis of an angiomyolipoma of the liver. Computed tomography during arterial portography is a commonly performed preoperative imaging modality. Therefore, recognition of angiomyolipoma of the liver by this technique is important, because this benign mesenchymal neoplasm may not require resection.

Adult↗
PubMed1994

Intrahepatic cholangiocarcinoma: findings on spiral CT during arterial portography.

To attempt to determine the characteristic imaging features of intrahepatic cholangiocarcinoma on spiral CT during arterial portography (CTAP), spiral CTAP examinations of 17 patients with pathologically confirmed intrahepatic cholangiocarcinoma were reviewed in consensus by three radiologists. The diameter of the tumors ranged from 1 to 12 cm (mean diameter, 6.6 cm). All tumors (100%) were hypoattenuating masses on spiral CTAP. In 11 cases, the tumor was homogeneous in attenuation (65%). Tumor margins were smooth and regular in 11 cases (65%). Vascular invasion was found in 14 cases (82%). Intrahepatic bile duct dilatation was present in seven cases (41%). This review shows that intrahepatic cholangiocarcinoma is associated with a constellation of findings on spiral CTAP. The presence of a low attenuation homogeneous intrahepatic mass with vascular invasion and intrahepatic bile duct dilatation on spiral CTAP images should raise the possibility of intrahepatic cholangiocarcinoma. However, these findings can be associated with other types of primary and secondary malignant hepatic tumors.

Adult↗
PubMed1994

Dynamic Gd-DOTA-enhanced MR imaging of hepatic metastases from pancreatic neuroendocrine tumors.

The aim of this study was to determine the MR imaging features of hepatic metastases from pancreatic neuroendocrine tumors (HMPNT), and to assess their enhancement characteristics on dynamic gadolinium-chelate-enhanced MR imaging. Twelve consecutive patients with pathologically proven HMPNT underwent spin-echo (SE) and dynamic gradient-recalled echo (GRE) MR imaging before and after intravenous administration of a gadolinium-chelate (gadolinium tetraazacyclododecanetetraacetic acid; Gd-DOTA). MR examinations were performed prospectively and interpreted retrospectively in consensus by two radiologists. Fifty-five HMPNT were identified in matching anatomic sections on the different MR sequences and included in the study. On T1-weighted SE images, 45 HMPNT (82%) were hypointense and 10 HMPNT (18%) were isointense. On T2-weighted SE images 55 HMPNT (100%) were hyperintense. On GRE images obtained 20 s after Gd-DOTA injection, 41 HMPNT (75%) showed slight peripheral enhancement, and 14 HMPNT (25%) showed internal enhancement. Forty-four HMPNT (80%) were heterogeneous. On GRE images obtained 4 min after Gd-DOTA injection, 37 HMPNT (67%) showed peripheral enhancement, and 18 HMPNT (33%) showed a global and almost complete enhancement. Heterogeneity of enhancement was seen in all 55 HMPNT (100%). Although HMPNT exhibit a large spectrum of MR features, early enhancement and heterogeneity on dynamic GRE MR images are suggestive features of HMPNT.

Adult↗
PubMed1994

Functional evaluation of normal and ischemic kidney by means of gadolinium-DOTA enhanced TurboFLASH MR imaging: a preliminary comparison with 99Tc-MAG3 dynamic scintigraphy.

The functional value of TurboFLASH MR imaging in the assessment of dynamic contrast enhancement and renal perfusion anomalies was evaluated in seven patients, who also underwent renal scintigraphy in baseline conditions. The basal renograms obtained from MAG-3 scintigraphy (mercapto acetyl triglycine, MAG3-S) and from Gd-DOTA-enhanced turboFLASH MRI were compared. After hydration, the protocol used consisted in breath-hold coronal turboFLASH acquisitions after IV bolus of Gd-DOTA (4 s every 20 s during 10 min) for MRI, and IV bolus of 370 MBq of 99mTc-MAG3 followed by 60 frames of 1 s and then 120 frames of 10 s for MAG3-S. Relative renal functions were computed for both methods by calculation of the integral of the uptake phase between the first and the second minute. Renograms exhibited 10 normal and 4 ischemic kidneys. There was a close correlation between the contrast enhancement of MRI and isotopic uptake in normal and ischemic kidneys. Global renograms of MRI correlated with MAG3-S (r = .82, p < .001) with similar curve shape and time to peak. Relative renal function of the right and left kidney were closely correlated in all patients (r = .98, p < .001), although there was a tendency for MR to overestimate MAG3-S evaluation in kidneys with severe basal dysfunction. Enhanced turboFLASH provides noninvasive assessment of renal perfusion in patients with renovascular disease. Accurate renograms are obtained with dynamic-enhanced MRI, but the relative renal function seems to be overestimated in low values of ischemic kidneys, and needs further comparative evaluation.

Adult↗
PubMed1994

Focal hepatic masses: comparison of detection during arterial portography with MR imaging and CT.

PURPOSE: A prospective study was performed to compare the sensitivity and specificity of magnetic resonance (MR) imaging and computed tomography (CT) both performed during arterial portography in depicting focal hepatic masses. MATERIALS AND METHODS: Eleven patients with 31 pathologically proved focal hepatic masses were prospectively evaluated. MR arterial portography was performed with 4 mL of a 0.5 mmol/kg solution of gadolinium tetraazacyclododecanetetraacetic acid (DOTA) injected through a catheter into the superior mesenteric artery during multisection gradient-echo imaging. RESULTS: MR arterial portography depicted 29 of the 31 masses (sensitivity, 94%). CT arterial portography depicted 27 of the 31 masses (sensitivity, 87%). Two masses not depicted with either CT or MR had a diameter of 3 and 7 mm, respectively. Neither MR nor CT demonstrated a false-positive finding (specificity, 100%). The difference in sensitivity and specificity between the two techniques was not statistically significant. CONCLUSION: MR arterial portography does not enable detection of significantly more focal hepatic masses than does CT arterial portography.

Female↗
PubMed1994

Enlarged mediastinal lymph nodes in bronchogenic carcinoma: assessment with dynamic contrast-enhanced MR imaging. Work in progress.

PURPOSE: To determine whether dynamic contrast material-enhanced magnetic resonance (MR) imaging can help differentiate between malignant and benign mediastinal lymph nodes (MLNs) in bronchogenic carcinoma. MATERIALS AND METHODS: Nine patients with biopsy-proved lung carcinoma underwent dynamic contrast-enhanced MR imaging before undergoing thoracic surgery. MR studies included spin-echo, electrocardiographically gated axial and coronal sequences and transaxial gradient-echo breath-hold sequences, which were performed after administration of a bolus of gadoterate meglumine. The enhancement curves were established on the basis of mean signal intensities from regions of interest at the level of tumor and the enlarged MLN. MR images were compared with pathologic specimens obtained at surgical resection. RESULTS: Metastatic MLNs exhibited their peak enhancement at 60-80 seconds, with a slow decrease until 6 minutes. Granulomatous and anthracotic lymph nodes displayed a slight enhancement, with no peak within 6 minutes (P < .01). CONCLUSION: Dynamic contrast-enhanced MR images may provide informative data about the nature of enlarged MLNs in the preoperative assessment of lung carcinoma. Further studies are needed to investigate its usefulness in clinical practice.

Aged↗
PubMed1994

Primary malignant neoplasms of the liver: detection with helical CT during arterial portography.

PURPOSE: To assess the sensitivity of helical computed tomography during arterial portography (CTAP) in the detection of primary malignant neoplasms of the liver. MATERIALS AND METHODS: Preoperative helical CTAP examinations of 19 patients (13 men, six women, aged 33-78 years) with primary malignant neoplasms of the liver (hepatoma, n = 12; cholangiocarcinoma, n = 4; angiosarcoma, n = 1; biliary cystadenoma, n = 1; hepatoblastoma, n = 1) were retrospectively reviewed by three radiologists. Imaging findings were correlated with intraoperative and pathologic findings. RESULTS: A total of 29 separate malignant neoplastic nodules (mean diameter, 6.6 cm) were identified in the resected specimens (16 patients) or intraoperatively in three patients. The overall sensitivity of helical CTAP was 72%; for neoplasms with a diameter less than 1.0 cm, 25%; for neoplasms 1.1-2.0 cm and 2.1-4.0 cm, 25% and 67%, respectively; and for neoplasms over 4.0 cm, 100%. CONCLUSION: The overall sensitivity of helical CTAP in the preoperative detection of primary malignant hepatic neoplasms is low.

Adult↗
PubMed1994

Hepatic metastases from colorectal cancer: detection and false-positive findings with helical CT during arterial portography.

PURPOSE: To determine the sensitivity and false-positive rate of helical computed tomography during arterial portography (CTAP) in the detection of hepatic metastases from colorectal cancer. MATERIALS AND METHODS: Preoperative helical CTAP was performed to examine 23 patients (10 men and 13 women, aged 43-77 years [mean, 63 years]) who later underwent surgical tumor resection. Imaging findings were retrospectively reviewed by two radiologists and were correlated with intraoperative and histologic findings. RESULTS: Helical CTAP demonstrated 33 of 35 metastases, with diameters of 4-95 mm, that were identified in resected specimens (sensitivity, 94%). The two metastases not demonstrated were 4 and 5 mm in diameter. Five false-positive lesions were found in four patients, yielding a false-positive rate of 17% by patient analysis and 13% by lesion analysis. CONCLUSION: The sensitivity of helical CTAP in the preoperative detection of hepatic metastases is high, and its false-positive rate compares favorably with that of conventional CTAP, but future comparative studies are needed to determine which is the better modality.

Colorectal Neoplasms↗
PubMed1994

CT of hepatic tumors: prevalence and specificity of retraction of the adjacent liver capsule.

OBJECTIVE: The purpose of this study was to describe the CT features of capsular retraction of the liver adjacent to hepatic tumors and to test the hypothesis that this finding is specific for malignant hepatic tumors. MATERIALS AND METHODS: We first retrospectively reviewed the CT scans of eight patients with pathologically proved malignant hepatic tumors (five secondary and three primary) who had CT scans that showed retraction of the overlying liver capsule. Then, using criteria developed from the first eight cases, we prospectively studied 253 patients with pathologically proved hepatic tumors (75 benign, 178 malignant) to determine the prevalence of retraction of the liver capsule shown by CT and the specificity of this finding for malignant hepatic tumors. RESULTS: CT scans in the first eight patients showed two types of capsular retraction. In seven patients, the retracted liver capsule was smooth and regular. In one patient, capsular retraction was associated with central ulceration extending to and eroding the liver capsule. Four of 253 patients studied prospectively had hepatic tumors with associated capsular retraction (prevalence, 2%). In those four cases, the retracted liver capsule was smooth and regular. All four tumors were malignant (one fibrolamellar hepatocellular carcinoma, two carcinoid tumors, one colorectal metastasis). CONCLUSION: Capsular retraction of the liver adjacent to hepatic tumors is an uncommon CT finding that appears to be specific for malignant hepatic tumors.

Carcinoma, Hepatocellular↗
PubMed1994

Detection of recurrent hepatic metastases after partial hepatectomy: value of CT combined with arterial portography.

OBJECTIVE: We did a retrospective study to evaluate the sensitivity of CT combined with arterial portography in detecting recurrent hepatic metastases after partial hepatectomy. MATERIALS AND METHODS: CT scans combined with arterial portography in 18 patients who had partial hepatectomy and suspected intrahepatic recurrence of metastases were retrospectively reviewed. Eleven of the patients had further surgery, and recurrent hepatic metastases were proved; seven patients were inoperable. The sensitivity of CT with arterial portography for detecting recurrent intrahepatic metastases was determined and correlated with intraoperative findings and findings on follow-up imaging studies in the 11 patients (with a total of 23 hepatic metastases) who had further surgery. RESULTS: Not one of the 18 CT examinations combined with arterial portography was compromised by inhomogeneous perfusion of contrast material in the portal vein. Of the 23 metastases that were found in the 11 patients who had further surgery, 21 (91%) were shown on CT with arterial portography. In two patients, CT with arterial portography showed two subcapsular hypoattenuating pseudolesions that were correctly identified as nontumorous perfusion defects, as confirmed by intraoperative findings and follow-up imaging studies. CONCLUSION: This study shows that postoperative CT with arterial portography is efficacious in the detection of intrahepatic recurrent metastases in patients who have had a partial hepatectomy. Furthermore, prior partial hepatectomy does not compromise the quality of this examination.

Colorectal Neoplasms↗
PubMed1994

Surgical segmental anatomy of the liver: demonstration with spiral CT during arterial portography and multiplanar reconstruction.

A major role of imaging in the evaluation of hepatic tumors is to assist surgeons in the preoperative determination of the feasibility of hepatic resection. Although the segmental location of tumors is not the sole criterion for determining resectability, such knowledge is useful for preoperative planning of the type of resection. This essay illustrates the surgical segmental and subsegmental anatomy of the liver as shown by spiral CT during arterial portography (CTAP) with multiplanar reformation.

Hepatectomy↗
PubMed1994

CT during arterial portography for the preoperative evaluation of hepatic tumors: how, when, and why?

CT during arterial portography (CTAP) is the most sensitive technique for the detection of intrahepatic tumors. CTAP is based on portal enhancement of the liver by infusion of contrast material through the superior mesenteric artery. This technique provides clear delineation of intrahepatic vessels, allowing segmental location of tumors to be accurately determined and relationships between tumors and intrahepatic vessels to be assessed. CTAP must be limited to patients for whom noninvasive preoperative imaging examinations have shown a potential for hepatic resection. In the majority of the cases, CTAP is performed in patients with hepatic metastases from colorectal cancer, but other types of tumor (either primary or secondary) may be an indication for CTAP. Visualization of nontumorous 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 MR imaging findings helps characterize portal perfusion defects. 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. The use of spiral CT shows promise in the performance of CTAP.

Humans↗
PubMed1994

Persistent enhancement after treatment for cerebral toxoplasmosis in patients with AIDS: predictive value for subsequent recurrence.

PURPOSE: To determine the predictive imaging (CT and/or MR) features of brain toxoplasmosis recurrences in acquired immunodeficiency syndrome. METHODS: The imaging studies of patients with brain toxoplasmosis were retrospectively reviewed. Forty-three patients with significant decrease or disappearance of brain lesions under specific treatment on follow-up imaging examinations were included. MR examinations were performed using T2- and T1-weighted sequences, before and after intravenous administration of gadolinium-DOTA. RESULTS: A recurrence occurred in 11 (26%) of 43 cases. Ten (91%) of these 11 patients with recurrence showed focal persistent enhancement after the initial treatment of toxoplasmosis abscess. One of the 11 patients with recurrence showed no persistent enhancement; 3 patients showed persistent enhancement but had no recurrence. CONCLUSIONS: Recurrences of brain toxoplasmosis in our series correlated with persistent contrast enhancement. We hypothesize that demonstration of persistent areas of contrast enhancement after treatment for initial toxoplasmosis may be a valuable sign for identifying patients at risk for recurrence.

AIDS-Related Opportunistic Infections↗
PubMed1993

Hodgkin's and non-Hodgkin's hepatic lymphoma: sonographic findings.

The sonographic studies of 72 patients with pathologically proven Hodgkin's or non-Hodgkin's hepatic lymphoma were retrospectively reviewed. Sixty-eight patients (94%) had secondary hepatic lymphoma (nine of them had AIDS-related lymphoma) and four patients (6%) had primary lymphoma of the liver. Forty-six of 72 patients (64%) had diffuse hepatic involvement, and 26 of 72 patients (36%) had focal liver lesions as demonstrated by sonography. Four patterns of disease were identified: (a) hepatomegaly was depicted by sonography in 26 of the 59 patients with secondary hepatic lymphoma not related to AIDS, in two of the nine patients with AIDS-related secondary hepatic lymphoma, and in one of the four patients with primary hepatic lymphoma; (b) multiple rounded well-delineated hypoechoic liver lesions were found in 22 of the 68 patients with secondary hepatic lymphoma; (c) a large heterogeneous echoic mass, which was an evocating clue to the diagnosis of primary lymphoma of the liver, was found in the four patients with primary lymphoma of the liver; and (d) an absence of sonographic abnormalities was found in 20 of the 59 patients with secondary lymphoma not related to AIDS. Liver involvement with lymphoma should be considered in any patient who develops multiple homogeneous hypoechoic liver masses, even in the absence of known underlying lymphomatous disease.

Adult↗
PubMed1993

High-resolution sonographic guidance for transjugular liver biopsy.

A prospective randomized study was performed to compare conventional right internal jugular vein catheterization technique with high-resolution sonographically guided catheterization for transjugular liver biopsy. Forty-seven patients were assigned to undergo either conventional or high-resolution sonographically guided right internal jugular vein catheterization for transjugular liver biopsy. Sonographic guidance was significantly better than conventional guidance, reducing the number of failed catheterizations, from 22% (5 of 23) to 0% (0 of 24) (p < .05). Sonography also reduced the mean number (+/- SD) of passes required to catheterize the vein from 4.21 +/- 1.53 to 1.54 +/- 0.66 (p < .001) and was successful in 100% (5 of 5) of patients in whom conventional catheterization failed. High-resolution sonographic guidance is strongly recommended for transjugular liver biopsy in patients at high risk for bleeding.

Adult↗