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Biomedical subjects

W Schima

Publications and source records attributed to W Schima.

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

[Videocinematography of swallowing. Indications, methodology and findings].

The purpose of this study was to given an introduction to the radiological evaluation of deglutition. The symptoms leading to videofluoroscopic investigation of swallowing are explained. The examination has to be tailored to the patient's symptoms. Each film scene depicts a characteristic patient position, a particular kind of contrast material and a certain amount. A systematic approach to analyze video films of deglutition and knowledge of the normal and abnormal swallowing functions are mandatory.

Cineradiography↗
PubMed1995

[Radiologic assessment of globus pharyngis. Comparison of the diagnostic value of conventional roentgen with videocinematography].

The feeling of having a lump in the throat is a common complaint of ENT outpatients. The symptom is associated with a multitude of pharyngoesophageal abnormalities. Our study compares the diagnostic yield of videofluoroscopy to that of static radiography in patients suffering from globus pharnygis. A total of 150 consecutive patients complaining of a lump in the throat, but without evidence of dysphagia, were studied in a standardized fashion with both methods. Videofluoroscopy combined with static radiography revealed morphological or functional abnormalities in 75% of our patients. The combination of the two methods yielded significantly more abnormalities in the pharynx and esophagus than videofluoroscopy (P < 0.0001) or static radiography alone (P < 0.0001). Esophageal motor disorders, pharyngoesophageal sphincter dysfunction and pharyngeal residue of contrast material proved to be the most common abnormalities. In conclusion, videofluoroscopy combined with static radiography is mandatory in the radiological assessment of patients suffering from the globus sensation.

Adolescent↗
PubMed1995

Videoradiography of free jejunal grafts for rehabilitation of speech in laryngectomized patients.

In laryngectomized patients a tracheo-esophageal artificial fistula can be used to achieve air flow from the trachea to the esophagus during speech. A one-way plastic valve is often used for the fistula. A free jejunal graft between the trachea and the esophagus can also be used. To avoid aspiration the transplant is attached to the submental area giving the graft a siphon-like shape. We performed 23 videoradiographic examinations using high-density barium in 14 such patients. The aim was to evaluate the protective function of these grafts against aspiration. Penetration of the bolus and a small amount of residual contrast material in the ascending limb of the graft was a normal finding. If the standard barium bolus reached the descending limb at any time during the examination, this was a sign of aspiration hazard. To avoid aspiration, the vertex of the speech siphon should be higher than the level of the hypopharyngeal anastomosis.

Anastomosis, Surgical↗
PubMed1994

Case report: sicca syndrome due to primary amyloidosis.

Sicca syndrome consists of two major clinical findings: keratoconjunctivitis sicca and xerostomia due to destruction of the lacrimal and salivary gland parenchyma. Although it is most often due to Sjögren's syndrome, a variety of other diseases causes sicca syndrome. We report the rare case of a patient with gland infiltration in primary amyloidosis. Sonographic, computed tomographic and magnetic resonance findings are presented.

Amyloidosis↗
PubMed1994

Preoperative staging of osteosarcoma: efficacy of MR imaging in detecting joint involvement.

OBJECTIVE: Selecting the appropriate surgical procedure for treatment of patients with osteosarcoma requires accurate preoperative evaluation of tumor extent. Establishing the presence or absence of joint involvement is particularly important. Accordingly, we studied the efficacy of MR imaging for detecting joint involvement in 46 patients with osteosarcoma around joint spaces. SUBJECTS AND METHODS: Preoperative MR examinations were performed in 46 consecutive patients with osteosarcoma whose tumors were located around the knee (n = 33), the hip (n = 8), or the shoulder (n = 5). T2-weighted and unenhanced and contrast-enhanced T1-weighted spin-echo MR images were obtained for all patients. We assessed the presence or absence of tumor invasion of the intracapsular-intrasynovial joint space, either by disruption of the joint capsule or by intraarticular destruction of the cortical bone and articular cartilage or the intracapsular-extrasynovial cruciate ligaments of the knee. All patients subsequently had surgery. The MR findings were correlated with findings from macroscopic and microscopic pathologic examinations. RESULTS: All 10 patients who subsequently proved to have tumor involvement of the joint were correctly identified (sensitivity, 100%). The tumor involved the knee joint in seven patients, the hip joint in two, and the shoulder joint in one. However, the MR diagnosis was false-positive in another 11 patients who did not have joint involvement at surgery (specificity, 69%). In the knee, MR imaging was more accurate in identifying tumor extension to the cruciate ligaments than to the intrasynovial joint space. Post-contrast T1-weighted images were most useful in detecting joint involvement. CONCLUSION: MR imaging is highly sensitive for detecting joint invasion of osteosarcoma. However, false-positive diagnoses may lead to overstaging of tumor and result in unnecessarily radical surgical procedures.

Adolescent↗
PubMed1994

Sensitivity of radionuclide bolus transport and videofluoroscopic studies compared with manometry in the detection of achalasia.

OBJECTIVE: The sensitivity of radionuclide bolus transport and videofluoroscopic studies to confirm manometrically revealed achalasia was investigated prospectively in 77 patients with symptoms indicative of disordered esophageal motor function. METHODS: The studies were performed in random order and were analyzed blindly by strict diagnostic criteria. Transport of radiolabeled water was recorded for 2 min with patients supine. Videofluoroscopy assessed three swallows in prone oblique and one in upright position. Manometry employed four pressure sensors in the esophageal body and the Dent sleeve in the lower esophageal sphincter. RESULTS: Radionuclide and videofluoroscopic studies confirmed 25 and 15, respectively, of 37 manometrically diagnosed achalasias and provided indications for the disorder in another 8 and 16 patients. Using information from both studies increased the sensitivity to detect achalasia from 68% and 41%, respectively, to 73%, and increased detection of disordered esophageal motor function from 81% and 74% to 92%. CONCLUSION: Radionuclide and videofluoroscopic studies represent valuable and complementary, although relatively insensitive, procedures to detect achalasia.

Colloids↗
PubMed1993

[The importance of magnetic field strength in the MR diagnosis of multiple sclerosis: a comparison of 0.5 and 1.5 T].

The value of magnetic resonance (MR) to establish the diagnosis of multiple sclerosis (MS) is well known. This study was undertaken to compare MR imaging of the brain of MS patients at high (1.5T) and mid (0.5T) field strength. 25 patients with MS underwent two consecutive MR studies within one hour, each consisting of axial proton density and T2-weighted spin-echo images. Lesions in the supratentorial white matter and corpus callosum and those in the brain stem and cerebellum were separately counted. At 1.5T significantly more lesions were seen than at 0.5T (p < 0.05). Although T2-weighted images at 1.5T added significant information compared to images obtained at 0.5T, in none of our 25 patients the diagnosis was missed at 0.5T. However, at 1.5T dissemination in space was better demonstrated, suggesting MR scanning with high field-units to be favourable in patients with clinically suspected MS.

Adult↗
PubMed1993

Superparamagnetic particles as oral contrast medium in magnetic resonance imaging of patients with treated ovarian cancer--comparison with plain MRI.

In 23 patients with treated ovarian cancer, 24 magnetic resonance (MR) examinations of the abdomen and pelvis were performed before and after administration of an oral superparamagnetic contrast medium. Depiction of bowel loops was judged sufficient in 47% with plain scans and in 85% with enhanced scans. Minor artefacts attributed to the agent were noted in 32% of examinations and were classified as disturbing in 8%. The diagnostic information obtained after contrast enhancement was estimated to be superior to that from plain MRI in 20% of patients. The use of oral contrast medium did not alter the MR diagnosis of "tumour recurrence" or "disease-free" in any patient. Our results suggest that superparamagnetic iron oxide is an effective and reliable approach to negative bowel contrast enhancement, increasing the confidence level when distinguishing intestines from solid structures.

Adult↗
PubMed1992

Esophageal motor disorders: videofluoroscopic and manometric evaluation--prospective study in 88 symptomatic patients.

Esophageal motor disorders are best evaluated with manometry, which, however, is time-consuming and not generally available. The authors prospectively investigated the yield of videofluoroscopy in detection of esophageal motor disorders in comparison with that of manometry. Eighty-eight patients with dysphagia, globus sensation, noncardiac chest pain, or progressive systemic sclerosis underwent both manometry and videofluoroscopy at 0-32-day intervals. Videofluoroscopy was performed with one swallowing study in the upright position and up to three swallowing studies in the prone oblique position. Manometric diagnoses of achalasia (n = 15), diffuse esophageal spasm (n = 1), nonspecific esophageal motor disorders (n = 44), and adynamic esophagus (n = 9) were made. Videofluoroscopically, 87% of the patients with achalasia, the one patient with diffuse spasms, 73% of the patients with nonspecific esophageal motor disorders, and all of the patients with adynamic esophagus received a correct diagnosis, for an overall sensitivity of 80%. The radiographic specificity was 79%. The authors conclude that videofluoroscopy is a valuable and reasonably sensitive technique for screening for esophageal motor disorders.

Adolescent↗
PubMed1992

[A cholecysto-enteric fistula with a gallstone ileus diagnosed by CT].

Gallstone ileus is an uncommon but severe complication of cholecystitis, which can only occur following perforation of the gallbladder and formation of a cholecystoenteric fistula. The diagnosis can be established by means of abdominal plain film when the classic triad described by Rigler (small-bowel obstruction, ectopic gallstone and pneumobilia) is observed. A patient with abdominal obstruction and equivocal findings on plain film X-ray and abdominal sonography is presented, in whom the gallstone ileus was reliably diagnosed by CT.

Aged↗
PubMedDate not supplied

Contrast-enhanced MR imaging of the liver: comparison between Gd-BOPTA and Mangafodipir.

The purpose of the study was to evaluate the MR contrast agents gadolinium benzyloxypropionictetro-acetate (Gd-BOPTA) and Mangafodipir for liver enhancement and the lesion-liver contrast on T1W spin-echo (SE) and gradient-recalled-echo (GRE) images. Fifty-one patients (three groups of 17 patients each) with known or suspected liver lesions were evaluated with T1W SE (300/12) and GRE (77-80/2.3-2.5/80 degrees) images before and after intravenous (IV) Gd-BOPTA (0.1 or 0.05 mmol/kg) or Mangafodipir (5 mumol/kg) in phase II to III clinical trials. Quantitative analysis by calculating liver signal-to-noise ratio (SNR), lesion-liver contrast-to-noise ratio (CNR), and spleen-liver CNR was performed. Liver SNR and spleen-liver CNR were always significantly increased postcontrast. SNR was highest after application of 0.1 mmol/kg Gd-BOPTA (51.3 +/- 3.6, P < .05). CNR was highest after Mangafodipir (-22.6 +/- 2.7), but this was not significantly different from others (P = .07). Overall, GRE images were superior to SE images for SNR and CNR. Mangafodipir and Gd-BOPTA (0.1 mmol/kg) provide equal liver enhancement and lesion conspicuity postcontrast. By all criteria, contrast-enhanced T1-weighted GRE were comparable to SE images.

Adult↗
PubMedDate not supplied

Videofluoroscopy of the pharynx and esophagus in chronic graft-versus-host disease.

Successful allogeneic bone marrow transplantation (BMT) for hematologic disorders may be complicated by graft-versus-host-disease (GVHD). Chronic GVHD is a systemic disease, involving, among other organs, the skin, mouth, liver, and esophagus. Esophageal involvement results in mucosal inflammation, leading to submucosal fibrosis and, occasionally, formation of webs and strictures. We investigated 25 allogeneic BMT recipients (17 with and eight without chronic GVHD). All patients had a videofluoroscopic study of the pharynx and esophagus to determine the radiographic abnormalities characteristic of chronic GVHD. Oropharyngeal abnormalities (poor bolus control, pharyngeal retention, or excessive mucous secretions) were found in five patients with and three patients without GVHD. Only one patient with GVHD had a pharyngo-esophageal stricture. There was no significant difference between the two groups with regard to pharyngo-esophageal radiographic abnormalities and esophageal symptoms. Radiographic evidence of esophageal motility disorder is not specific for GVHD involvement. In the absence of specific radiographic features, endoscopy is the most accurate method for the diagnosis of esophageal involvement by GVHD.

Adult↗
PubMedDate not supplied

Spiral computed tomographic angiography of the renal arteries: a prospective comparison with intravenous and intraarterial digital subtraction angiography.

PURPOSE: To assess the accuracy of computed tomographic angiography (CTA) in the evaluation of the renal arteries in comparison with intravenous (IVDSA) and intraarterial digital subtraction angiography (IADSA). METHODS: In 18 patients, 35 CTAs and DSAs (27 IADSA, 8 IVDSA) of the renal arteries were performed. CTA was done with 2-3 mm collimation,2-4 mm/sec table speed, after intravenous injection of 80 ml of contrast medium at 4 ml/sec with a scanning delay time of 14-21 sec. No previous circulation time curve was performed. CTA data were reconstructed with maximum intensity projection (MIP) and shaded surface display (SSD). The presence of stenosis was assessed on a three-point rating scale (grade 1-3). The quality of the examinations; visualization of the ostium, the main artery, and its branches; vessel sharpness, linearity, and intraluminal contrast filling were evaluated. We compared CTA with DSA. RESULTS: CTA had 96% sensitivity, 77% specificity, and 89% accuracy in the detection of stenoses > 50%. Due to technical errors two stenoses were erroneously diagnosed as positive but there were no false negative diagnoses. The quality of CTA was good in 56% and moderate in 34% of cases. Visualization of the ostium and main artery was graded as 1.74 (out of 2) points and of the renal branches as 1.02 (out of 2) points and of the renal branches as 1.02 (out of 2) points. The quality of CTA images was worse than that of IADSA in 52%, equal in 41%, and better in 7% of cases. CTA was equal to IVDSA in 25% and better in 75% of the cases. CONCLUSION: CTA is an accurate noninvasive method for the evaluation of renal arteries. Examination quality is essential for the diagnosis. CTA is limited in its ability to visualize the branches of the renal artery and accessory arteries. CTA seems to be superior to IVDSA.

Adult↗
PubMedDate not supplied

Comparison of in-phase and out-of-phase gradient recalled echo T1-weighted pulse sequence for MR imaging of malignant liver masses following administration of paramagnetic gadolinium-chelate.

BACKGROUND: The purpose of this study was to compare the performance of in-phase and out-of-phase gradient recalled echo (GRE) pulse sequences on paramagnetic contrast-enhanced magnetic resonance (MR) imaging of malignant liver lesions. METHODS: Fifty patients (27 women, 23 men; mean age = 50 +/- 27 years) with known or suspected focal liver lesions, nine of whom had a fatty liver, were examined at 1.5 T before and 60 min after injection of gadobenate dimeglumine at a dose of 0.05 or 0.1 mmol/kg using two GRE techniques: echo time of 2.3 ms (out-of-phase) or 4.6 ms (in-phase). Liver signal-to-noise ratio (SNR) and lesion-liver contrast-to-noise ratio (CNR) were calculated. RESULTS: In patients with a nonfatty liver, liver SNR increased from 26 +/- 9 to 41 +/- 17 on in-phase images and from 28 +/- 8 to 45 +/- 14 on out-of-phase images. In patients with a fatty liver, in-phase images provided significantly higher (p < 0.01) liver SNR than did out-of-phase images predose (34 +/- 8 on in-phase vs. 21 +/- 8 on out-of-phase) and postdose (44 +/- 13 on in-phase vs. 33 +/- 14 on out-of-phase). In patients with a nonfatty liver, lesion-liver CNR was similar on in-phase and out-of-phase images, predose and postdose. In patients with fatty liver, lesion-liver CNR was significantly (p < 0.01) lower on out-of-phase images on predose and postdose images. CONCLUSION: In-phase GRE imaging is recommended for imaging focal liver lesions on paramagnetic contrast-enhanced MR imaging in patients with fatty infiltration of the liver.

Adult↗
PubMedDate not supplied

Transluminal radiofrequency tissue ablation with use of metallic stents.

PURPOSE: To determine if transluminal coagulative necrosis can be induced by applying radiofrequency (RF) energy to indwelling metallic stents. MATERIALS AND METHODS: RF energy was applied to metallic alloy stents (20-68 mm length, 5-16 mm diameter) in tissue phantom (n = 31), ex vivo bovine liver (n = 10), and in vivo porcine hepatic veins (n = 4). For ex vivo and in vivo liver experiments, RF was applied for 5-6 minutes, titrating generator output to produce 85 degrees-95 degrees C temperatures at the stent surface. Local and remote temperature sensing was performed. Imaging and pathologic studies documented the extent of coagulation necrosis. RESULTS: Phantom studies demonstrated uniform temperature distribution along the entire stent length for all Elgiloy stents powered for 2 minutes with a minimum of 120 watts. Shorter stents required less power or reduced time to achieve uniform temperature. In ex vivo liver, 25-mm stents (n = 5) showed 8-10 mm of uniform circumferential coagulation necrosis along the entire stent length. Fifty-millimeter stents showed less uniform coagulation necrosis. For the in vivo stents (20 mm), 8-10 mm of uniform circumferential coagulation necrosis surrounded the stent along its entire length. CONCLUSION: Metallic stents can be used to deliver transluminal RF energy from an external source, inducing heat deposition with resultant circumferential tissue coagulation. Clinical applications might include reduction of intimal proliferation in vascular diseases and/or treatment of periluminal tumors compressing the bile ducts, the urethra, or other luminal structures.

Animals↗
PubMedDate not supplied

Percutaneous radiofrequency tissue ablation: does perfusion-mediated tissue cooling limit coagulation necrosis?

PURPOSE: To determine, by decreasing hepatic perfusion during radiofrequency (RF) ablation, whether perfusion-mediated tissue cooling can explain the reduced coagulation observed in in vivo studies compared to that seen with RF application in ex vivo tissue. MATERIALS AND METHODS: RF was applied in vivo with use of cooled-tip electrodes to normal porcine liver without (n = 8) and with balloon occlusion of the portal vein (n = 8), celiac artery (n = 3), or hepatic artery (n = 2), and to ex vivo calf liver (n = 10). In vivo trials of vasopressin (0.3-0.6 U/min) infusion during RF application with (n = 10) and without (n = 2) arterial balloon occlusion were also performed. Intraoperative RF was subsequently performed in seven patients with hepatic colorectal metastases with and without portal inflow occlusion. Remote thermometry was performed in four patients. RESULTS: RF application (12 minutes) during portal venous occlusion produced larger areas of coagulation necrosis than RF with unaltered blood flow (2.9 cm +/- 0.1 vs 2.4 cm +/- 0.2 diameter; P < .01). With celiac and hepatic artery occlusion, coagulation diameter measured 2.7 cm +/- 0.2 and 2.5 cm +/- 0.1, respectively. Infusion of vasopressin without vascular occlusion reduced coagulation diameter to 1.1 cm. However, different methods of hepatic or celiac arterial balloon occlusion with simultaneous vasopressin infusion produced a mean 3.4 cm +/- 0.2 of necrosis. Coagulation in ex vivo liver was 2.9 cm +/- 0.1 in diameter. Clinical studies demonstrated greater coagulation diameter for metastases treated during portal inflow occlusion (4.0 cm +/- 1.3) than for tumors treated with normal blood flow (2.5 cm +/- 0.8; P < .05). Thermometry documented a 10 degrees C increase compared to baseline at 10 mm and 20 mm from the electrode after 5 minutes of portal inflow occlusion during constant RF application. CONCLUSIONS: Perfusion-mediated tissue cooling reduces coagulation necrosis achievable with RF ablation. Reduction of blood flow during RF application increases coagulation in both an animal model and human liver metastases.

Aged↗