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Biomedical subjects

M Kunnen

Publications and source records attributed to M Kunnen.

At least 19 recordsLinked to original sources
PubMed2001

T1 relaxation times for viability evaluation of the engrafted and the native liver in a rat model of heterotopic auxiliary liver transplantation: a pilot study.

Following a heterotopic auxiliary liver transplantation, commonly used measurements are either invasive or non-indicative of individual viability of the coexisting engrafted and native livers. Magnetic resonance imaging (MRI) was therefore tested for its potential to monitor the post-transplant hepatic viability in a rat model. Thirteen Wistar rats were systematically evaluated with MRI and serum biochemical liver parameters. Post-transplant complications and the causes of animal death were identified by autopsy and histo-pathological examinations. The data of the healthy survivors were compared with those of the rats that developed complications. On MRI, the hepatic complications could be depicted in the individual livers. A specific pattern of signal evolution was found in the livers of the healthy survivors: the mean T1 relaxation times of the engrafted livers increased immediately after transplantation (476 +/- 64 ms, mean +/- standard deviation, pre-operative; 730 +/- 48 ms, week 1) and then declined steadily to a 3 month value of 489 +/- 246 ms, while, following a transient first rise (476 +/- 64 ms, pre-operative; 589 +/- 28 ms, week 1), the mean T1 value of the native livers increased again 4 weeks after surgery and reached a 3 month value of 859 +/- 43 ms. However, in the rats with various complications, the mean T1 relaxation times of the engrafted livers continued to increase throughout the first post-operative month (760 +/- 48 ms, week 1; 922 +/- 76 ms, week 4), while that of the native liver only varied mildly (546 +/- 25 ms, week 1; 473 +/- 25 ms, week 4). After the first post-transplant week, the healthy engrafted livers could already be distinguished from those with complications by a significant decrease in T1 relaxation times. These data suggest that, besides demonstrating major complications, MRI may allow one to monitor the viability of each liver by analysing the relative signal intensity and T1 relaxation times after a heterotopic auxiliary liver transplantation.

Alanine Transaminase↗
PubMed2001

Hemangiopericytoma of the parotid gland: CT and MR features.

Hemangiopericytomas are uncommon vascular neoplasms with rare occurrence in the head and neck region. They originate from the pericytes, which are small, oval cells encircling capillaries. Hemangiopericytomas traditionally appear in the retroperitoneum and in the capillaries of the extremities. A case of hemangiopericytoma of the parotid gland is presented. The clinical, surgical, histologic, and radiologic features are described and discussed.

Adult↗
PubMed2001

Skull base granuloma: an unusual location of idiopathic midline destructive disease.

A rare case of idiopathic midline destructive disease is presented, which is an entity of the so-called midline granuloma syndrome. Differentiation from other granulomas, especially from Wegener's granulomatosis, is important. This report shows the MR findings in a patient with atypical clinical presentation of histopathologically proven idiopathic midline destructive disease.

Aged↗
PubMed2001

CT and MRI of the semicircular canals in the normal and diseased temporal bone.

Imaging of the semicircular canals specifically is part of the imaging process of the temporal bone in general. The semicircular canals are easily seen on CT images and 3DFT-CISS-weighted MR images, both performed with 1.0-mm-thick slices, or even thinner slices. In selected cases, the T1-weighted images give unique information on the semicircular canals. This article briefly reviews the variety of semicircular canal anomalies that are most frequently present and can be routinely seen on CT and MR examinations of the temporal bone. It also provides a list that can be used by the radiologist in clinical practice to decide which technique, CT or MR, should be used to detect specific anomalies at the level of the semicircular canals.

Humans↗
PubMed2001

Embolization as a first approach with endoscopically unmanageable acute nonvariceal gastrointestinal hemorrhage.

PURPOSE: To determine technical and clinical results of embolization of endoscopically unmanageable nonvariceal gastrointestinal hemorrhage (GIH). MATERIALS AND METHODS: Results of 40 embolizations in 91 patients who underwent arteriography for acute nonvariceal GIH were retrospectively studied. GIH was upper, lower, or transpapillar (hemobilia, pancreatic duct bleeding). Clinical parameters and embolization data were assessed for clinical success and in-hospital survival. RESULTS: Technical success (bleeding target devascularization) was achieved in all patients except one with upper GIH (39 [98%] of 40 patients). No bowel complications occurred. One partial liver lobe and one partial spleen infarction were noted. Five (13%) of 39 patients bled again within 3 days; all had upper GIH (P =.049). Clinical success (no rebleeding after 30 days) was achieved in 32 (82%) of 39 patients. Clinical success occurred in 13 (68%) of 19 patients with upper GIH, in 10 (91%) of 11 with lower GIH, and in all with transpapillar GIH (P =.084). Mortality rate was 28% (11 of 40 patients), equally spread over upper, lower, and transpapillar GIH (P =.87). Blood loss (hemoglobin level < 80 g/L, P =.041), use of packed cells (P =.049) and fresh frozen plasma (P =.006); shock (P =.047); and corticosteroid use (P =.036) were related to rebleeding. Shock (P =.039) and use of fresh frozen plasma (P =.003) before embolization and rebleeding (P =.012), coagulopathy (P =.007), and need for surgery (P =.03) after embolization were strongly correlated with mortality. CONCLUSION: Embolization is an effective first approach with lower and transpapillar GIH after endoscopy; it was less effective with upper GIH.

Acute Disease↗
PubMed2000

Value of MR cholangiography in the evaluation of postoperative biliary complications following orthotopic liver transplantation.

The aim of this study was to describe the spectrum of abnormal biliary findings as seen with magnetic resonance cholangiography (MRC) in symptomatic patients after orthotopic liver transplantation (OLT). In our study we included 12 consecutive patients post-OLT who presented with clinical and/or biochemical suspicion of biliary complications. In all patients MRC was performed on a 1.0-T whole-body magnet and breathhold half-Fourier acquired single-shot turbo spin echo and rapid acquisition with relaxation enhancement sequences were used. Diagnostic confirmation was obtained with percutaneous transhepatic cholangiography (PTC; n = 3 patients), endoscopic retrograde cholangiography (ERC; n = 3 patients), or clinical follow-up. A vast array of biliary abnormalities were detected in 11 of 12 patients: high-grade, obstructive, anastomotic stricture was the most common unique abnormality. Findings consistent with bile duct necrosis, the second most common abnormality, were accompanied by arterial abnormalities in 2 of 5 patients on subsequent MR- and digital subtraction angiography. Compared with the findings obtained with direct cholangiography (n = 5 patients), MRC was highly accurate for the detection and characterization of postoperative biliary complications. Compared with the final diagnosis, which was based on PTC-ERC findings and/or all available clinical data, MRC imaging alone was able to provide a specific diagnosis in 9 of 12 patients. Magnetic resonance cholangiography is an accurate, time-saving, and non-invasive imaging modality in the evaluation of post-OLT patients in whom suspicion of biliary complications exists. Although the precise value of MRA in this patient group requires larger dedicated studies, single session "all-in-one" MR evaluation of both biliary and arterial system in our series proved to be a substantial benefit in obtaining an accurate and complete diagnosis.

Adult↗
PubMed2000

Postoperative findings following the Whipple procedure: determination of prevalence and morphologic abdominal CT features.

This study was conducted to determine characteristic CT findings following the Whipple procedure and to evaluate the usefulness of CT in predicting tumor recurrence. Eighty-four postoperative abdominal CT scans and medical records of 43 patients were retrospectively reviewed. Perioperative histopathologic examinations revealed malignancy in 32 patients (74.4 %). Time interval between surgery and CT varied from 13 days to 6 years and 7 months. Common postoperative findings were unopacified anastomotic bowel loops in the porta hepatis (n = 69 scans), perivascular cuffing (n = 42 scans), pneumobilia (n = 40 scans), dilated intrahepatic bile ducts (n = 22 scans), reactive lymphadenopathy (n = 21 scans), and transient fluid collections (n = 20 scans). Postoperative complications were detected on 17 CT scans (20.2 %): generalized ascites (n = 8 patients), deep abscesses (n = 3 patients), wound abscess (n = 1 patient), pancreatitis (n = 1 patient), and pseudomembranous colitis (n = 1 patient). Tumor recurrence appeared in 15 patients (46.8 %) after a mean postoperative period of 11 months (1 month to 3 years): local (9 of 15), regional lymph nodes (9 of 15), and liver metastasis (8 of 15). Detection of generalized ascites more than 30 days after surgery was associated with tumor recurrence in 6 of 6 patients (100 %). Diffuse ascites (> 30 days after surgery) behaved as an early predictive sign of tumor recurrence. In our series CT accuracy for detecting recurrent tumor with CT was 93.5 %. No predilection site for disease recurrence could be determined.

Adult↗
PubMed2000

Heparin-induced thrombocytopenia and fat necrosis of the breast.

Fat necrosis of the breast is a well-known complication following trauma, surgery, or radiotherapy. The present paper describes a rare case of fat necrosis after heparin-induced thrombocytopenia. The mammographic, sonographic, and MR evaluation and pathologic correlation after a 1-year follow-up period are reported.

Aged↗
PubMed2000

MRI of the brain in cerebrotendinous xanthomatosis (van Bogaert-Scherer-Epstein disease).

The clinical, biochemical and magnetic resonance imaging findings of two patients with cerebrotendinous xanthomatosis are reported. This is a rare hereditary disease. Early recognition of this entity is important in view of the existing treatment possibilities. Magnetic resonance imaging findings typically include a bilateral and almost symmetrical increase of the signal intensity on the T2-weighted images in the cerebellar and periventricular cerebral white matter, the basal ganglia, the dentate nuclei and the brainstem as well as cerebellar and cerebral atrophy.

Adult↗
PubMed2000

Cervical chordoma with vertebral artery encasement mimicking neurofibroma: MRI findings.

A case of cervical chordoma in a 36-year-old white man with hypoesthesia in the neck and right shoulder, neck pain, and restricted neck mobility is presented. Plain radiographs of the cervical spine showed radiolucency of the body of C2 on the right side and enlargement of the right intervertebral foramen at C2-C3 level. Tumor encasement of the vertebral artery was demonstrated by MR imaging and confirmed by conventional arteriography. This proved to be particularly important for preoperative assessment.

Adult↗
PubMed2000

Cineradiography of the pharyngoesophageal segment in postlaryngectomy patients.

The use of tracheoesophageal voice prostheses has gained wide acceptance in the field of vocal rehabilitation after total laryngectomy. In a randomized study with 3 arms, alaryngeal speech proficiency was assessed in 60 postlaryngectomy patients: 20 patients underwent primary unilateral pharyngeal myotomy, 21 patients underwent neurectomy of the pharyngeal plexus in addition to pharyngeal myotomy, and 19 patients did not undergo an additional surgical procedure. Pharyngoesophageal (PE) dynamics were examined during esophageal and tracheoesophageal speech. A single vibrating PE segment was seen in good alaryngeal speakers. Hypertonicity, spasm, strictures, and hypotonicity of the PE segment were correlated significantly with poor or moderate alaryngeal speech. Unilateral myotomy with or without unilateral neurectomy prevented hypertonicity or spasm of the PE segment. The acquisition of alaryngeal speech did not differ significantly between the 2 groups who had undergone an additional surgical procedure. Evaluation of anatomic and physiological factors may be helpful in subsequent clinical management to achieve effective alaryngeal speech.

Adult↗
PubMed2000

Transvenous embolization of a dural arteriovenous fistula of the anterior cranial fossa: preliminary results.

We report two cases of a dural arteriovenous fistula of the anterior cranial fossa, one causing subarachnoid hemorrhage and one detected accidentally. The first case was incompletely treated by neurosurgery, and the second one was referred for endovascular therapy. Both fistulas were successfully occluded by transvenous embolization by using electrolytically detachable coils.

Adult↗
PubMed2000

Giant intraluminal duodenal diverticulum: conventional barium study and computed tomography findings.

A case is reported of an asymptomatic intraluminal duodenal diverticulum (IDD) in a 21-year-old male patient with associated congenital abnormalities. During endoscopy for anemia an ostium in the duodenum was visualized, presumed to be the entry to an extraduodenal diverticulum. Upper gastrointestinal (UGI) barium examination showed, however, findings compatible with IDD. This diagnosis was supported by an abdominal computed tomographic (CT) examination. Surgical resection revealed a web in D2 with coexistent large IDD.

Adult↗
PubMed1999

Accuracy of single-sequence MRI for investigation of the fluid-filled spaces in the inner ear and cerebellopontine angle.

We prospectively studied 163 patients referred for MRI of the temporal bone. A presumed diagnosis was made using only one of three sequences: a single thick (12 mm) slice fast T2-sequence, 3D fourier transform constructive interference in steady state (3DFT-CISS) sequence and a gadolinium-enhanced T1-weighted sequence. The visibility of the cochlea, vestibule and superior, lateral and posterior semicircular canals of normal temporal bones was assessed on the T2-weighted images: they were almost always visible (98-100%), with exception of the superior semicircular canal, seen in only 35% of cases. The images were interpreted as abnormal in 34 patients (21%). Using only the fast T2-weighted, 3DFT-CISS and gadolinium-enhanced T1-weighted sequences a presumed false positive diagnosis was made in 5, 1 and 0 cases and a false negative diagnosis in 2, 2 and 4 cases respectively. The overall reliability of the thick-section fast T2-weighted images is limited. This study suggests that a combination of gadolinium-enhanced T1-weighted and 3DFT-CISS images can be considered the gold standard for temporal bone MRI and neither sequence performed separately is as accurate as both together.

Adolescent↗