Biomedical subjects

M Keberle

Publications and source records attributed to M Keberle.

30 records · Page 2Linked to original sources

PubMed2000

Technical advances in ultrasound and MR imaging of carpal tunnel syndrome.

The aim of this study was to compare the latest ultrasound-array technology to a conventional "high-resolution" transducer, modified MRI technique, and nerve conduction studies (NCS), in the diagnosis of carpal tunnel syndrome (CTS). In 19 normal wrists and 15 wrists with CTS, US with two different transducers was performed: a conventional linear-array transducer (LA) and a newly developed Multi-D linear-array transducer (MDA) were used. The US images were evaluated determining the swelling and the flattening ratios of the median nerve and correlated to respective findings in MRI (1.5 T) and to NCS. The NCS confirmed CTS in all 15 wrists. Measures of median nerve compression (swelling and flattening ratios) were significantly different in patients with CTS and controls (p < 0.01) with both types of US transducers and MRI. The MDA yielded higher correlation to MRI than the LA. Using critical values of 1.3 for the swelling and 3.4 for the flattening ratio, MRI, and US with the MDA yielded a sensitivity of 100% each. Modern imaging modalities allow for an exact diagnosis of CTS even in cases with only slight median nerve pathology.

Adult↗

PubMed2000

[Comparison of contrast harmonic imaging in B-mode with stimulated acoustic emission, conventional B-mode US and spiral CT in the detection of focal liver lesions].

PURPOSE: Comparison between contrast harmonic imaging (CHI) in B-mode with stimulated acoustic emission (SAE), conventional B-mode US, and spiral CT in the detection of focal liver lesions. METHODS: In this pilot study 26 patients with liver lesions diagnosed by B-mode US and contrast-enhanced spiral-CT were additionally examined with CHI in B-mode. Each examination started with a bolus injection of 4 g of the US contrast agent Levovist (300 mg/ml) after a delay of at least 5 minutes to ensure liver-specific phase. All examinations were documented on video tapes and analysed by two radiologists. RESULTS: 81 liver lesions were diagnosed with both US examinations and spiral CT. B-mode US detected 66 lesions, CHI with SAE 72 lesions, and spiral CT 73 lesions. Compared to spiral CT 8 lesions in 3 patients could be depicted additionally with both US methods. Metastases and HCC present in CHI with SAE as not-enhancing signal contrast agent areas. Delineation of haemangiomas and FNH was often worse compared to the native examinations. CONCLUSION: The new US method CHI with SAE depicted more lesions than conventional B-mode US and is in some cases superior to spiral CT.

Adult↗

PubMed2000

[New possibilities in the diagnosis and documentation using 3D power doppler ultrasound with carcinoma of the floor of the mouth as illustration].

AIM: To evaluate a novel 3D power Doppler ultrasound-technique (3D PDUS) in the diagnosis and documentation of tumours of the floor of the mouth. METHOD: 22 patients with tumours of the floor of the mouth (2 T1-, 5 T2-, 6 T3- and 9 T4-carcinomas) prospectively underwent conventional grey-scale ultrasound combined with power Doppler ultrasound and 3D PDUS (3-Scape). All examinations were performed with the "Sonoline Elegra Advanced" in combination with a 7.5 MHz transducer. Two independent observers compared the results regarding clear tumour margins, midline crossing, infiltration of the mylohyoid muscle, infrahyoidal tumour, contact to the mandible, contact to major vessels (such as the lingual, submental and/or facial artery), intra- and peritumoural vascularisation and judged the value of the 3D reconstruction method for documentation purpose. RESULTS: All parameters relevant for therapy could be gathered from the 3D data (agreement: 98.2%) almost without loss of information; results of both observers were identical (kappa value: 1.0). In the comparison to conventional ultrasound, 3D PDUS also allows for the reconstruction of axial images of the floor of the mouth similar to CT-images, and a 3D image of tumour vascularisation can be obtained. Acquisition and reconstruction of the 3D data only takes a couple of minutes. CONCLUSIONS: "3-Scape" is a novel easy-to-perform method allowing the complete acquisition of 3D data of the entire floor of the mouth, and providing the possibility to digitally store and/or transfer examination results without loss of information. Reconstruction of ultrasound-images in any desirable plane and/or as a 3D presentation is possible. Thus, in the future, additional software will facilitate the determination of the volume and the degree of vascularisation of tumours.

Adult↗

PubMed2000

[3D power Doppler ultrasound: new possibilities in the diagnosis and documentation of tumors of the base of the tongue].

BACKGROUND: To evaluate a novel 3-D power Doppler ultrasound technique (3-D PDUS) in the diagnosis and documentation of tumors of the base of the tongue. PATIENTS AND METHODS: Twenty patients with tumors of the base of the tongue (2T1, 6T2, 6T3, and 6T4 carcinomas) prospectively underwent two-dimensional gray scale and power Doppler ultrasound and 3-D PDUS (3-Scape). All examinations were performed with a 7.5 MHz transducer and the Sonoline Elegra Advanced. Two independent observers compared the examinations regarding clear tumor margins, maximal diameter of the tumor, midline crossing, infiltration of the mylohyoid muscle, infrahyoidal tumor, contact to the lingual artery, vascularization in the tumor and in surrounding tissue, and evaluated the documentary use of the 3-D reconstruction. RESULTS: All relevant pretreatment parameters were accessible in the 3-D data; results of both observers were almost identical. An acquisition and reconstruction of the 3-D data takes only a couple of minutes. In addition to two-dimensional ultrasound 3-D PDUS allows reconstruction of axial images of the base of the tongue similar to CT images and a 3-D visualization of tumor vascularization. CONCLUSIONS: 3-Scape is a novel user-friendly method that allows uninterrupted acquisition of large 3-D volumes, and digital storage and transmission of ultrasound studies without loss of information. US images can be reconstructed in any desired plane or visualized in 3-D. In the future, additional software will permit exact determination of the volume and degree of vascularization of tumors.

Adult↗

PubMed2000

Assessment of microvascular changes in Raynaud's phenomenon and connective tissue disease using colour doppler ultrasound.

OBJECTIVE: We used colour Doppler ultrasound (CDU) to differentiate primary from secondary Raynaud's phenomenon (pRP and sRP, respectively) and to assess digital vascular damage in patients with connective tissue disease (CTD). METHODS: Vascularity in the nailbeds of 15 healthy controls and 35 patients with CTD (systemic sclerosis or systemic lupus erythematosus) was quantified using a multi-D array transducer before and after cold and warm challenge, respectively. The results were compared with the clinically evaluated initial skin lesions. Vascularity was compared similarly between 10 pRP and 22 sRP patients. RESULTS: Vascularity at ambient temperature differed between healthy subjects and sRP patients as well as between healthy subjects and CTD patients without initial skin lesions. Patients with pRP had normal vascularity at ambient temperature but differed from healthy controls in response to a dynamic temperature challenge. CDU confirmed the clinical evaluation in 89.4% of the patients with RP and in 78.0% of the skin lesions. CONCLUSION: The novel CDU technique presented here makes it possible to discriminate between pRP and sRP and to quantify vascular changes in CTD patients.

Adult↗

PubMed2000

Detection of pharyngeal perforation: comparison of aqueous and barium-containing contrast agents.

OBJECTIVE: We sought to assess the value of aqueous and barium-containing contrast agents in the detection of pharyngeal perforation. SUBJECTS AND METHODS: Visual and objective in vitro comparisons of an iodinated aqueous contrast agent, a 50% weight/volume barium suspension, and a 100% weight/volume barium suspension were performed. Moreover, to exclude pharyngeal perforation after surgery, we prospectively examined 109 patients by pharyngography, using the aqueous contrast agent and the 100% weight/volume barium suspension. All patients with a pharyngeal perforation were followed up clinically to exclude complications due to barium application. RESULTS: As opposed to the 100% weight/volume barium suspension, in vitro comparison between the aqueous contrast agent and the 50% weight/volume barium suspension yielded no substantial differences. Seventeen perforations could be detected with the aqueous contrast agent. Although 10 of 17 perforations could be slightly better visualized with the 100% weight/volume barium suspension, two perforations were missed with this agent. Five perforations were equally well detected with both. CONCLUSION: Because of a higher radiopacity, 100% weight/volume barium suspensions may more sharply delineate perforations. However, in contrast to aqueous contrast media, narrow pharyngeal perforations can be missed. Thus, the use of a 100% weight/volume barium suspension does not improve the detection of pharyngeal perforation.

Adult↗

PubMed1999

Evaluation of pannus and vascularization of the metacarpophalangeal and proximal interphalangeal joints in rheumatoid arthritis by high-resolution ultrasound (multidimensional linear array).

OBJECTIVE: To evaluate the extent of intraarticular vascularization and pannus formation in metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints of patients with rheumatoid arthritis (RA) by high-resolution ultrasound (US). METHODS: A newly developed, high-resolution multidimensional linear array US was utilized to obtain longitudinal and transverse scans of joints with active RA (n = 21), moderately active RA (n = 39), or inactive RA (n = 93), and of joints from healthy controls (n = 120). RESULTS: Healthy joints had no detectable pannus, whereas pannus could be detected in 52% of the joints with active RA, 82% of the joints with moderately active RA, and 67% of the joints with inactive RA. There was a significant difference in vascularization in the joints of all subgroups of RA patients and those of healthy subjects (P < 0.001). Moreover, vascularization differed significantly among the RA subgroups: inactive versus moderately active RA (P < 0.02) and inactive versus active RA (P < 0.05). Both pannus and vascularization appeared to be localized preferentially on the radial side of the joints. CONCLUSION: Evaluation of pannus and the extent of vascularization within the joints of patients with RA by high-resolution US might be helpful in the assessment of disease activity, and thus influence therapeutic strategies.

Adult↗

PubMed1999

Current value of double-contrast pharyngography and of computed tomography for the detection and for staging of hypopharyngeal, oropharyngeal and supraglottic tumors.

In light of recent endoscopic techniques the current value of double-contrast pharyngography (DCP) and of CT for detection and staging of hypo-, oropharyngeal, and supraglottic tumors is evaluated. The DCP of 151 patients and CT obtained from 99 of these patients were retrospectively analyzed in a double-blinded manner. We used a standard protocol which comprised all relevant anatomical subregions. Results were compared with direct microlaryngoscopy (DL), indirect laryngoscopy (IL), and post-operative histopathological findings. Sensitivity and specificity of DCP was 75.0 % and 86.7 %, respectively. The DCP and IL techniques together yielded a higher sensitivity (96.7 %) than each method separately. Sensitivity and specificity of CT was 87.5 and 100 %, respectively. In 74.7 % CT provided correct staging. Subregional analysis revealed that the results of DCP and CT depend highly on the localization of the tumor. Our results indicate that DCP represents an important screening method for diagnosing hypo-, oropharyngeal, and supraglottic tumors to complete IL and DL. We show that CT is a reliable method for preoperative staging, although small superficial tumors may occasionally be missed by this method.

Administration, Oral↗

PubMed1998

[The stepchild of intestinal diagnosis. Evaluation of radiologic methods in the diagnosis of leiomyoma of the small intestine].

PURPOSE: Various radiological methods to diagnose small bowel neoplasms and problems of differential diagnosis specially considering leiomyomas are discussed. PATIENTS AND METHODS: Two patients with leiomyoma of the ileum underwent enteroclysis, computed tomography of the abdomen, intra-arterial DSA and colour Doppler sonography. Another patient with leiomyosarcoma just underwent CT of the abdomen with CT-guided biopsy. RESULTS: Due to the homogenous density and the smooth surface of the tumors in computed tomography and respectively enteroclysis and the presentation of the tumor vascularisation in the angiography and Colour Doppler sonography in both patients a leiomyoma of the small bowel was diagnosed. Postoperatively this diagnosis was histologically confirmed. The CT-findings of the patient with leiomyosarcoma were not suspicious of a malignant tumor. CONCLUSION: Radiologically it is not possible to determine the dignity of smooth muscle cell tumors safely. That is the reason why the diagnosis has to be achieved operatively. But the histopathological diagnosis based on the mitotic rate may be difficult. Therefore the after care has to be carried out thoroughly.

Aged↗

PubMed1994

A comparison of transesophageal echocardiography and transcranial Doppler sonography with contrast medium for detection of patent foramen ovale.

BACKGROUND: Patent foramen ovale as a possible stroke risk factor can be diagnosed with transcranial Doppler sonography (TCD) by detecting intravenous contrast medium crossing from the right to the left atrium. The present study evaluates the reliability of this method. SUMMARY OF REPORT: We performed TCD and transesophageal echocardiography simultaneously in 50 patients using galactose microbubbles. We observed bubble signals passing the middle cerebral artery in 7 patients less than 20 seconds after injection; we found positive TCD tests in 14 patients using the Valsalva maneuver. With transesophageal echocardiography patent foramen ovale could be detected in 15 patients (sensitivity, 0.93; specificity, 1; P < .01). CONCLUSIONS: TCD with echo contrast is a reliable screening tool for patent foramen ovale. A standardized procedure including the Valsalva maneuver is essential to prevent false-negative results.

Adult↗

PubMedDate not supplied

Three-dimensional power Doppler sonography in screening for carotid artery disease.

PURPOSE: Color Doppler sonography has gained considerable recognition as a noninvasive method to detect carotid artery disease and to assess the degree of carotid artery stenosis. However, results are highly operator-dependent and cannot be presented as survey images. The purpose of this study was to evaluate real-time 3-dimensional (3D) power Doppler sonography as a method for screening for atherosclerosis in the carotid arteries. METHODS: We prospectively screened 75 patients for carotid artery disease using both conventional color Doppler sonography and 3D power Doppler sonography, and the results from the 2 modalities were compared. A total of 150 common carotid arteries, 150 internal carotid arteries, and 150 external carotid arteries were examined utilizing a 7.5-MHz linear-array transducer combined with tissue harmonic imaging. RESULTS: Color Doppler sonography detected 297 normal or atherosclerotic arteries without stenosis, 57 arteries with mild (1-49%) stenosis, 41 with moderate (50-69%) stenosis, 32 with severe (70-99%) stenosis, and 9 with occlusions. The degree of stenosis determined by color Doppler sonography correlated with that determined by 3D power Doppler sonography (r = 0.982-0.998). Moreover, there was a good correlation between the measurements for both the length of the lesion and its distance from the bulb as determined by the 3D volume surveys and by color Doppler sonography (r = 0.986). The interobserver variability rate was 3.7% +/- 0.5%. Generally, the acquisition and reconstruction of the 3D data took less than 5 minutes. CONCLUSIONS: 3D power Doppler sonography is easy to perform and is an accurate method in screening for atherosclerotic lesions of the carotid arteries. Moreover, it provides excellent 3D volume surveys that may be helpful in the planning of surgical treatment.

Aged↗

PubMedDate not supplied

Hepatic angiomyoma: CT and MRI findings.

Angiomyoma is a benign tumor that arises from soft muscular tissue within the blood vessel wall. This lesion has been found in different organs. The preferential location of these tumors is the lower extremity. We describe the rare case of a hepatic angiomyoma and present the radiologic findings of computed tomography and magnetic resonance imaging.

Angiomyoma↗