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Biomedical subjects

L Van Hoe

Publications and source records attributed to L Van Hoe.

At least 37 records · Page 2Linked to original sources
PubMed1998

A pancreatic mucinous cystadenoma in a man with mesenchymal stroma, expressing oestrogen and progesterone receptors.

A 43-year-old man presented with abdominal discomfort caused by relapsing pancreatitis. Radiological examination revealed a multilocular cystic mass in the tail of the pancreas, which was resected. Gross examination showed a multilocular cystic lesion measuring 2.5 cm in diameter and containing clear fluid. Microscopically, a mucinous cystadenoma with mesenchymal stroma was diagnosed. The lesion showed two different components: a cyst lined by a columnar, mucin-secreting epithelium and a moderate cellular stroma composed of spindle cells. The stromal element appeared similar to primitive mesenchyme. Immunohistochemical staining confirmed this origin through vimentin expression and showed moderate to strong nuclear staining with oestrogen and progesterone receptor antibodies. Cystadenomas are rare tumours of the pancreas, but mesenchymal stroma is uncommon in such tumours; it is more frequently described in the liver and the bile ducts, and primarily in women.

Adult↗
PubMed1998

Nonalcoholic duct-destructive chronic pancreatitis: imaging findings.

OBJECTIVE: Nonalcoholic duct-destructive chronic pancreatitis is a new entity that should be distinguished from alcoholic chronic pancreatitis. The purpose of this study was to assess the imaging features of nonalcoholic duct-destructive chronic pancreatitis. CONCLUSION: Nonalcoholic duct-destructive chronic pancreatitis has characteristic CT and MR imaging features that include the presence of a focal or more diffuse mass causing either regular or irregular narrowing of the main pancreatic duct, the absence of parenchymal atrophy and significant ductal dilatation proximal to the site of stenosis, and the absence of extrapancreatic spread.

Adolescent↗
PubMed1998

Normal Vaterian sphincter complex: evaluation of morphology and contractility with dynamic single-shot MR cholangiopancreatography.

OBJECTIVE: The objective of this study was to assess the usefulness of dynamic single-shot MR cholangiopancreatography in the evaluation of the morphology and contractility of the normal Vaterian sphincter complex and to assess whether i.v. injection of glucagon can improve visualization. SUBJECTS AND METHODS: Sixty patients without signs of Vaterian sphincter complex dysfunction were studied. A fast single-shot MR imaging sequence was used to obtain 20 consecutive images of the Vaterian sphincter complex during successive episodes of breathholding. In patients of group A (n = 30), 10 images were obtained before and 10 after i.v. administration of a sphincter-relaxing agent (glucagon). In the patients of group B (n = 30), no glucagon was administered. The degree of visualization of the Vaterian sphincter complex was assessed. RESULTS: Overall, the morphology and contractility of the Vaterian sphincter complex was adequately assessed in 57 patients (95%). However, the number of repetitions required to obtain this result varied greatly (mean, seven; range, two to 18). Glucagon had no apparent effect on the visibility of the most distal portion of the common bile duct. CONCLUSION: Nonvisualization of the most distal portion of the common bile duct on MR cholangiopancreatography studies is a normal variant that can simulate disease. Obtaining serial breath-hold images using a single-shot technique is helpful to avoid diagnostic errors.

Adult↗
PubMed1998

T2-weighted MR imaging of the uterus: comparison of optimized fast spin-echo and HASTE sequences with conventional fast spin-echo sequences.

OBJECTIVE: Our objective was to compare the value of a half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequence with optimized fast spin-echo and conventional fast spin-echo techniques in evaluation of the uterus. SUBJECTS AND METHODS: Optimized fast spin-echo imaging was compared with fast spin-echo and HASTE imaging, for both image quality and ability to assess the zonal anatomy of the uterus, in 40 volunteers. In optimized fast spin-echo imaging, the imaging time was reduced using partial-Fourier reconstruction, reducing the echo spacing, and increasing the echo train length. RESULTS: HASTE imaging offered the least motion artifact of all techniques. On optimized fast spin-echo imaging, motion artifacts were moderate to severe in 10% of patients. On fast spin-echo imaging, motion artifacts were moderate to severe in 40% of patients. Optimized fast spin-echo imaging was superior to the other two techniques in terms of anatomic sharpness and overall image quality. CONCLUSION: Although HASTE imaging offers the unique feature of providing images free of motion artifacts, optimized fast spin-echo imaging appears to be the preferred technique for T2-weighted imaging of the uterus.

Adolescent↗
PubMed1998

Benign mesenteric schwannoma: MRI findings.

Accurate differentiation of retro- or intraperitoneal localization of a primary abdominal tumor by US and CT is often difficult. In our case an abdominal mass was incidentally discovered and identified as a typical benign schwannoma, but with a very atypical location in the mesentery. We found that MRI was a valuable adjunct to CT for exact tumor localization.

Adult↗
PubMed1998

Osler-Rendu-Weber with liver involvement.

Osler-Rendu-Weber disease, or hereditary hemorrhagic telangiectasia, is a vascular disease with autosomal dominant transmission. The liver is involved in 31% of patients with hereditary hemorrhagic telangiectasia (1). It appears that the lesions uncommonly causes serious disease. We report the imaging findings and the therapy in a case with extensive telangiectasis in the liver.

Aged↗
PubMed1998

Intraperitoneal contrast material combined with CT for detection of peritoneal metastases of ovarian cancer.

OBJECTIVE: To determine the sensitivity and specificity of CT-peritoneography (CT-P) in detecting peritoneal carcinomatosis in primary or recurrent ovarian cancer. METHODS: Twenty-five patients were submitted to a standard abdominal CT (CT) as well as a computed tomography after intraperitoneal infusion of contrast material (CT-P). Twenty patients had ovarian masses clinically suspected to be malignant. In five patients with ovarian cancer who underwent prior debulking surgery, recurrent disease was suspected. RESULTS: In 21/25 patients an ovarian malignancy was histologically confirmed. During surgery peritoneal spread was found in 13 patients; only in 5 cases CT correctly suggested peritoneal metastases (sensitivity 38%). However, in 10/13 women CT-P indicated peritoneal spread, increasing the overall sensitivity from 38% to 77%. Sensitivity varied substantially according to the different abdominal areas, and was lowest in the left subphrenic space (25%). The sensitivity of CT-P was 71% and 72% in the right paracolic gutter and the pelvis, respectively. Sensitivity of CT-P was not found to be size-dependent, but was mainly related to the morphology of the lesions, with 100% sensitivity in nodular lesions, and only 21% sensitivity for flat peritoneal lesions. CT-P did not improve detection of omental metastases, and was not advantageous when ascites was present. Previous surgery reduced overall specificity from 80% to 57%. CONCLUSION: CT-P greatly improved the sensitivity of CT in the preoperative detection of peritoneal spread of ovarian malignancy. However, the technique failed to detect flat peritoneal metastases, and had a low specificity in patients with a history of prior abdominal surgery.

Contrast Media↗
PubMed1997

Preliminary experience with a new double-echo half-Fourier single-shot turbo spin echo acquisition in the characterization of liver lesions.

A new double-echo half-Fourier single-shot turbo spin echo technique has been implemented in which two images are obtained per excitation pulse, one with an echo time (TE) of 60 ms and another with a TE of 438 ms. The acquisition window per image is 380 ms and is determined by the echo spacing of 4.3 ms and the echo train length of 88 for images with resolution of 160 x 256. No breath holding was performed. The aim of the study was to test whether the additional information of the late TE image improves the characterization of liver lesions. Twenty-eight patients with 39 focal liver lesions (9 cysts, 11 hemangiomas, and 19 solid lesions) were imaged with the new technique, and signal intensity (SI) ratios of lesion and liver were obtained. A t-test analysis showed that in the TE 60 ms image, SI ratios of cysts and hemangiomas were not significantly different, whereas in the TE 438 ms images the two types of lesions can be classified. Signal intensity ratios of solid lesions were in both images clearly lower than those of cysts and hemangiomas. The technique, therefore, seems a promising and straightforward new tool for the characterization of liver lesions.

Cysts↗
PubMed1997

Gastroepiploic artery coronary bypass graft: non-invasive patency evaluation using color and duplex Doppler ultrasonography.

OBJECTIVE: Color and duplex Doppler ultrasound and digital subtraction angiography were compared for the evaluation of graft patency of the gastroepiploic artery (GEA). METHODS: In 77 observations, ultrasound and digital subtraction angiography were compared. The coronary resistance index (cRI) was defined as the maximal systolic flow velocity minus the maximal diastolic flow velocity, divided by the maximal systolic flow velocity. On digital subtraction angiography, the graft was considered patent, occluded, or patent but non-functional. Grafts were defined as non-functional when they had a diameter of less than 5F with the absence of opacification of the native coronary artery. RESULTS: Of the 77 observations, 64 GEAs were patent angiographically, three were occluded and ten grafts were considered as patent but non-functional. Using color and duplex ultrasound, the GEA was identified in 65 out of 77 observations. There were no cases of false positive visualization of the GEA. All sonographically detected non-functional grafts (n = 7) had a cRI of greater than 0.60. When the non-visualized grafts are considered either non-functional or occluded, a cut-off value for a cRI of 0.60 results in a sensitivity and specificity of 100 and 75%, respectively. CONCLUSION: We propose ultrasound as a primary screening tool for evaluating graft patency. While color Doppler is a suitable technique for graft visualization, spectral analysis with the calculation of a cRI is required for functional evaluation.

Adult↗
PubMed1997

Pancreatic carcinoma: applications for helical computed tomography.

Helical computed tomography (CT) represents a significant technical improvement over conventional (incremental) CT. This noninvasive imaging technique is now routinely used in the evaluation of patients with suspected pancreatic cancer. This paper focuses on the topics of CT technique (scanning parameters, use of intravenous contrast media, use of oral contrast media and spasmolytic agents, calculation of reformatted and projective images), as well as on the CT appearance of pancreatic carcinoma and the differential diagnosis and staging. A short comparison with other methods is included.

Adenocarcinoma↗
PubMed1997

Size quantification of liver metastases in patients undergoing cancer treatment: reproducibility of one-, two-, and three-dimensional measurements determined with spiral CT.

PURPOSE: To assess the reproducibility of one-, two-, and three-dimensional measurements of the size of liver metastases. MATERIALS AND METHODS: The sizes of 10 liver metastases were determined 200 times: Ten observers measured each lesion by using images obtained at two different CT studies and with five different measurement techniques (maximum diameter, product of diameters, area, volume, and product of three diameters). They repeated each measurement in a separate session. The influence of measurement technique and lesion type (size and morphologic appearance) on measurement reproducibility was assessed. RESULTS: Three-dimensional measurements proved to be as reproducible as one- and two-dimensional measurements. Measurement reproducibility was influenced mainly by the size (P < .0001) and morphologic appearance (P < .01) of the lesions. CONCLUSION: Three-dimensional size measurements obtained with spiral CT are reproducible and could therefore replace the two-dimensional measurements of tumor size currently obtained with follow-up CT studies.

Humans↗
PubMed1997

Dual-phase helical CT of the liver: value of an early-phase acquisition in the differential diagnosis of noncystic focal lesions.

OBJECTIVE: Contrast-enhanced helical CT images of the liver are usually obtained during the portal vein phase (PVP), during which the parenchyma achieves peak enhancement. The purpose of this study was to determine whether the addition of arterial-phase (AP) scans would lead to improved characterization of focal lesions. MATERIALS AND METHODS: We reviewed the CT appearance of 102 focal lesions with a proven diagnosis. In the first part of the study, we assessed whether the addition of AP scans influenced the diagnostic performance of the three observers. In the second part of the study, we analyzed the morphologic appearance revealed on CT scans of the different types of lesions in the AP and PVP. RESULTS: The addition of AP scans led to a significant increase in the number of correct diagnoses: 71 lesions (70%) were correctly diagnosed with CT scans in both the AP and the PVP, compared with 54 lesions (53%) correctly diagnosed with CT scans in the PVP alone (p < .01). The largest difference was observed in the diagnosis of focal nodular hyperplasia (FNH) and adenoma (16/24 correct diagnoses instead of 6/24) (p < .005). Conversely, AP images did not significantly contribute to the diagnosis of hemangiomas and metastases. The following morphologic features were seen much more often on AP scans than on PVP scans and had a high positive predictive value (PPV): spoke-wheel pattern (FNH; PPV, 100%), central feeding vessel (FNH; PPV, 100%), and heterogeneous appearance with hyperdense components (hepatocellular carcinoma; PPV, 75%). CONCLUSION: Our data show that the radiologists' evaluation of CT scans in both the AP and the PVP improves the differentiation of hepatocellular carcinoma and FNH from other types of hepatic neoplasms.

Adenoma, Liver Cell↗
PubMed1997

Imaging of gallbladder and biliary tract before laparoscopic cholecystectomy: comparison of intravenous cholangiography and the combined use of HASTE and single-shot RARE MR imaging.

To compare intravenous cholangiography (i.v.c.) and magnetic resonance imaging (MRI) as preoperative imaging techniques in patients scheduled for laparoscopic cholecystectomy. Twenty patients underwent i.v.c. and MRI, 40 axial 'localizer' images were first obtained with a half-Fourier single-shot turbo spin echo (HASTE) sequence. Next, an extremely high T2-weighted rapid acquisition relaxation enhancement (RARE) acquisition (TE = 1100 msec) was used for MR cholangiography. All images obtained with i.v.c. and MRI were independently analyzed by two observers. The relative visibility of the (normal or abnormal) gallbladder (GB), cystic duct (CD), and bile ducts (BD) on both types of images was scored as follows: 1 = MRI better than i.v.c.; 2 = no difference; 3 = i.v.c. better than MRI. We observed 3 anatomic variants: 1 of the cystic duct and 2 of the intrahepatic bile ducts; 15 patients had gallstones; one had cholecystitis. Magnetic resonance images were considered more informative than i.v.c.-images for visualization of GB in 11 patients (55%), for CD in 9 patients (45%), and in 8 patients (40%) for visualization of the CBD. Intravenous cholangiography outperformed MRI in the evaluation of the CBD and CD in one patient (5%). The combined use of half-Fourier single-shot RARE and high T2-weighted RARE MR imaging is a valuable alternative to i.v.c. in the preoperative evaluation of gallbladder and biliary tract.

Adult↗
PubMed1997

Torsion of accessory spleen in an adult patient: imaging findings at CT, MRI and angiography.

A 40-year-old woman presented with acute left upper quadrant pain due to torsion of an accessory spleen around its long vascular pedicle, causing infarction. Torsion of an accessory spleen is extremely rare. As far as we known only 14 cases have previously been reported in the literature, and more than half patients were children. MRI can be helpful in the differential diagnosis of infarction by suggesting haemorrhagic necrosis on the T2-weighted images.

Abdominal Pain↗