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Biomedical subjects

M Keberle

Publications and source records attributed to M Keberle.

At least 19 recordsLinked to original sources
PubMed2003

[Prognostic value of pretreatment CT regarding local control in oropharyngeal cancer after primary surgical resection].

PURPOSE: To evaluate the prognostic implication of tumor infiltration and volume in primarily operated oropharyngeal carcinomas. MATERIAL AND METHODS: In 80 patients with oropharyngeal squamous cell carcinomas (pT 1 = 22, pT 2 = 30, pT 3 = 19 and pT 4 = 9), the tumor volume was measured by pretreatment CT and the extent of tumor infiltration determined by postoperative histologic examination. All patients were followed clinically for local tumor recurrence for at least two years after therapy. The statistical analysis consisted of chi 2 and U tests. RESULTS: The local control rate was 79 % (63/80). Of all evaluated anatomic structures, only midline crossing correlated significantly with local recurrence (p = 0.06). No correlation of tumor volume (p = 0.19) or T stage (p = 0.60) with the local recurrence rate was found. CONCLUSION: After primary surgery, oropharyngeal carcinomas with midline crossing have an increased risk of local recurrence, whereas the tumor volume only has a minor impact on the recurrence rate. This is in contrast to laryngeal or hypopharyngeal carcinomas.

Adult↗
PubMed2003

[Diagnostic impact of multiplanar reformations in multi-slice CT of laryngeal and hypopharyngeal carcinomas].

PURPOSE: Assessment of the diagnostic value of multiplanar reformations (MPR) in multi-slice computed tomography (MSCT) by comparing relevant anatomic structures of the larynx and hypopharynx. MATERIALS AND METHODS: MSCT of the neck was performed in 69 consecutive patients (including 30 laryngeal and 12 hypopharyngeal carcinomas). From a 4 x 1.0 mm collimation data set, 3.0-mm and 1.25-mm axial slices as well as 3-mm coronal and sagittal slices were reconstructed. Using the histological examination as gold standard, sensitivity and specificity regarding tumor infiltration for all relevant anatomical structures of the larynx and the hypopharynx were determined for each reconstruction and compared with the McNemar test. Moreover, 42 patients with laryngeal and/or hypopharyngeal carcinoma were subjectively evaluated to determine whether the respective reconstructions enables a better topographical visualization of the tumor in relation to surrounding structures and, furthermore, whether this has an influence on the therapeutical strategy (operation versus radiation therapy, type of operation, surgical approach). RESULTS: Sensitivities and specificities were not significantly different between the reconstructions. However, coronal and sagittal MPR provided a better topographical visualization of the tumor in 14 of 42 (33 %) of the patients, and influenced the therapeutical strategy in 8 of 42 (19 %) of the patients. A lowered signal-to-noise ratio impeded the evaluation of the relatively thin 1.25-mm axial slices in more than 23 % of the cases. CONCLUSION: Besides the 3-mm axial slices, coronal and sagittal MPR can improve the topographical visualization of laryngopharyngeal tumors and are recommended for preoperative MSCT of laryngeal and/or hypopharyngeal carcinomas. Additionally reconstructed 1.25-mm axial slices can be discarded since they do not hold a higher value compared to 3-mm axial reconstructions.

Adult↗
PubMed2002

Current concepts in imaging of laryngeal and hypopharyngeal cancer.

In adjunct to direct laryngoscopy, CT and/or MRI are needed for an accurate staging of laryngeal and hypopharyngeal carcinomas because both cross-sectional imaging modalities are known to reliably evaluate deep tumor infiltration. Except for the clinical background, this article reviews technical aspects of CT and MRI, the pathologic appearance of laryngeal and hypopharyngeal carcinomas, and therapeutically relevant diagnostic aspects.

Adult↗
PubMed2002

High resolution ultrasound detects a decrease in pannus vascularisation of small finger joints in patients with rheumatoid arthritis receiving treatment with soluble tumour necrosis factor alpha receptor (etanercept).

OBJECTIVE: High resolution ultrasound (HRUS) was used to investigate the effects of tumour necrosis factor alpha (TNFalpha) blockade on pannus formation and vascularisation of small finger joints in patients with active rheumatoid arthritis (RA). METHODS: Five patients with active RA were treated with etanercept, a soluble TNFalpha receptor protein, for one month. Before, during, and after treatment the patients were followed up by clinical rheumatological examination, determination of their subjective pain score, blood chemistry, and by HRUS of the second metacarpophalangeal (MCP) joint of the right hand. RESULTS: One month after treatment with etanercept, rheumatological examination showed a significant decrease in a modified single joint rheumatic disease activity index (from 2.9 (SD 0.2) to 1.2 (0.7); p<0.05) in all patients. Moreover, a significant decrease in the general pain score (from 4.7 (0.4) to 1.8 (0.6); p<0.05) and in C reactive protein (CRP) levels was seen (from 3.02 (0.9) to 0.24 (0.1); p<0.05). Concordantly, HRUS showed a significant reduction in pannus vascularisation of the MCPII joints (from 23,602 (5339) to 2907 (1609) colour signals/region of interest, CS/ROI; p<0.001). Pearson's correlation coefficient between the results obtained by HRUS and the clinical response was 0.85. CONCLUSION: HRUS is promising as an additional useful method in the assessment of RA activity, and probably also in monitoring therapeutic responses.

Aged↗
PubMed2001

Spiral CT of the neck: When do neck malignancies delineate best during contrast enhancement?

The aim of this study was to determine the time of best contrast of neck malignancies in contrast-enhanced CT. The CT was done in 20 patients with squamous cell carcinoma using a standard protocol (100 ml contrast agent at 2 ml/s). Dynamic series of the tumors were performed (scan interval 6 s). In all relevant structures of the neck, densities were measured to obtain time-density curves. The best tumor contrast was measured > or =50 s after the start of the injection, and the best contrast of lymph nodes < or =75 s. For staging and volume measurements of neck primaries the best achievable contrast is necessary. Using the examined single-bolus technique, spiral CT allows a combination of perfect tumor contrast with a good contrast between lymph nodes and neck vessels between 50 and 75 s after starting the injection.

Aged↗
PubMed2001

[Comparison of 3D power doppler ultrasound, color doppler ultrasound and digital subtraction angiography in carotid stenosis].

PURPOSE: To compare easy-to-perform three-dimensional power Doppler ultrasound (3D PDUS) to color Doppler ultrasound (CDUS) and digital subtraction angiography (DSA) in the assessment of internal carotid artery (ICA) stenoses in patients with severe atherosclerosis. METHODS: 26 ICA's (7 without stenosis, 4 low-, 4 middle-, and 11 high-grade stenoses) in 13 patients were examined with DSA, CDUS, and 3D PDUS. CDUS and 3D PDUS were performed with a 7.5 MHz standard transducer and a Sonoline Elegra ultrasound machine. The three methods were performed and interpreted by different persons who were not aware of the diagnoses. RESULTS: Regarding the degree of stenosis correlations between DSA and 3D PDUS were r = 0.98 (p < 0.001), between DSA and CDUS r = 0.97 (p < 0.001), and between CDUS and 3D PDUS r = 0.95 (p < 0.001). Sensitivity and specificity regarding the detection of a high-degree stenosis was 90% and 100% for 3D PDUS, and 100% and 93.3% for CDUS. CONCLUSION: Even in cases with severe atherosclerosis, both sonographic methods reveal similar results comparable to DSA. 3D PDUS does not result in a diagnostic improvement on CDUS, however, it does give the new opportunity for complete data storage, reconstruction, and survey presentations.

Aged↗
PubMed2001

Clinical trial on the accuracy of a freehand and sensor-independent three-dimensional power Doppler ultrasound system measuring diameters, volumes and vascularity of malignant primaries of the neck.

AIM: Diameters, volumes and vascularity of malignant primaries of the neck are of substantial importance for staging and prognosis. The purpose of this study was to determine the accuracy of a newly developed freehand and sensor-independent three-dimensional power Doppler ultrasound system (3D PDUS) in the assessment of these parameters. METHOD: 24 patients with squamous cell carcinomas of the neck underwent conventional ultrasound in B- and power Doppler-mode (US), 3D PDUS, and computed tomography (CT). Diameters (sagittal, longitudinal, and transverse) and volumes of the tumours were correlated with hand-segmentated CT images, whereas tumour vascularity was compared with US. RESULTS: 3D PDUS and CT correlated highly regarding diameters and volumes (correlation coefficients r = 0.98/P < 0.001 and r = 0.98/P < 0.001, respectively). 3D PDUS and US correlated highly regarding vascularity (r = 0.92/P < 0.001). CONCLUSION: Although 3D PDUS is based on a freehand and sensorless data acquisition, it appears to be as accurate as CT or US for measurements of diameters, volumes and vascularity of neck malignancies. In spite of the excellent results it has to be mentioned that this technique needs a lot of training and its general use has to be employed with caution.

Adult↗
PubMed2001

[Interobserver variability in CT of oro- and hypopharyngeal carcinomas].

PURPOSE: To evaluate the inter- and intraobserver reproducibilities of computed tomography (CT) in patients with oro- and hypopharyngeal carcinomas. METHODS: Two independent readers interpreted the CT images of 41 patients with hypopharyngeal carcinomas, 45 patients with oropharyngeal carcinomas, and 23 patients without a tumor. All relevant subregional anatomic structures were evaluated for the presence of tumor infiltration. Statistical analysis was done by using Cohen's kappa and the Wilcoxon test; subregional prevalences, sensitivities, and specificities were also determined. RESULTS: Mostly, especially for clinically relevant subregions, moderate and substantial inter- and intraobserver reproducibilities were determined (range of the determined kappa values: 0.25-1.00). The kappa values of the intraobserver reproducibilities of both readers were not significantly different (P = 0.20). The kappa values of the intraobserver reproducibilities were in almost all the cases higher than the respective kappa values of the interobserver reproducibility. CONCLUSION: CT of oro- and hypopharyngeal carcinomas can be interpreted with clinically acceptable variability. A higher agreement can be achieved if repeated interpretation is done by a single person.

Adult↗
PubMed2001

[Comparison of iodinated and barium-containing contrast media of different viscosity in the detection of pharyngeal perforation].

PURPOSE: In contrast to esophageal perforations, the more radiopaque barium-suspensions are not as important as iodinated aqueous contrast agents for the detection of pharyngeal perforations. This study was performed to find out whether the highly different viscosities (of iodinated and barium-containing contrast agents with comparable radiopacities) are a reason for this. METHODS: Viscosity, subjective difference in contrast, and CT-density of an iodinated aqueous (Telebrix) and a 50 wt/vol% barium-containing contrast agent (Micropaque) were determined. Moreover, to exclude postoperative perforation, 104 patients were prospectively examined by pharyngography using both contrast media. Pharyngographies of patients with perforation were later compared by two independent readers. All patients with perforation were followed up clinically to exclude complications due to barium administration. RESULTS: In-vitro comparison showed comparable radiopacity but the 50 wt/vol% barium-suspension was much more viscous than the iodinated contrast agent. During pharyngography, totally, 14 perforations were clearly delineated with the iodinated aqueous contrast agent. However, two of them were not detected with the barium-suspension. All the other perforations presented equally. CONCLUSIONS: Given a sufficient radiopacity, a low viscosity appears to be essential for a contrast agent to detect especially pharyngeal perforations. Thus, we recommend the sole use of an iodinated contrast agent (at suspicion of aspiration as isoosmolar variant) for this purpose.

Adult↗
PubMed2001

Comparison of axial reconstructed ultrasonographic images from three-dimensional data volumes and computed tomographic scans in the documentation and detection of liver lesions.

OBJECTIVE: To compare axial reconstructed ultrasonographic images from three-dimensional data volumes and conventional computed tomographic scans in documentation and detection of liver lesions. METHODS: The livers of 23 patients were examined by a multifrequency curved array transducer to acquire three-dimensional data volumes and by conventional computed tomography The ultrasonographic device was equipped with three-dimensional ultrasonographic technology allowing for real-time parallel movement in every plane within an acquired data volume. Axial ultrasonographic images reconstructed from three-dimensional data volumes were compared with conventional computed tomographic scans. RESULTS: When both methods were taken together, a total of 51 different liver lesions could be detected. Reconstructed ultrasonographic images depicted 44 (86%) of 51 lesions, and computed tomographic scans showed 46 (90%) of 51 lesions. Compared with computed tomography, ultrasonography depicted 5 additional lesions in 3 of the patients (4 hemagiomas and 1 unspecified lesion), whereas 7 lesions were missed in another 4 patients (4 metastases, 2 calcifications, and 1 cyst). The Pearson correlation coefficient between ultrasonography and computed tomography was r = 0.84 (P < .001). CONCLUSIONS: Our study shows that ultrasonographic images can be effectively reconstructed from three-dimensional data volumes. With respect to documentation and detection of liver lesions, the results obtained by three-dimensional ultrasonography appear comparable with those obtained by conventional computed tomography. However, several technical and procedural limitations have to be respected.

Adult↗
PubMed2000

[Reninoma: a rare cause of hypertension. Case report, review of the literature and possibility for organ preserving operation].

A 20-year-old man with no past medical history and no clinical symptoms was referred for examination because of severe hypertension. The blood chemistry studies showed elevated levels of peripheral renin with evidence of secondary aldosteronism. Sonography and computed tomography demonstrated a mass of the left kidney. After excluding all other possible causes for severe hypertension, excision of the tumor was performed. Histological studies confirmed the diagnosis of a juxtaglomerular cell tumor. Reninoma represents a rare but surgically curable cause of hypertension. The clinical suspicion of this tumor is very important because of the young age of the patients. If the diagnosis is confirmed a renal sparing surgery should be the treatment of choice.

Adenocarcinoma↗
PubMed2000

Computed tomography after lymphangiography in the diagnosis of intestinal lymphangiectasia with protein-losing enteropathy in Noonan's syndrome.

Noonan's syndrome is a rare congenital disorder that may be associated with abnormalities in the lymphatic drainage. In this case of a 21-year-old man CT after bipedal lymphangiography confirmed the diagnosis of intestinal lymphangiectasy causing protein-losing enteropathy in Noonan's syndrome by showing contrast-enhanced abnormal lymphatic vessels in the mesentery and the intestinal wall. Because of the benefit of diet in case of intestinal involvement, we recommend a thorough documentation of the lymphatic drainage with lymphangiography followed by CT, if clinical signs of lymphatic dysplasia, such as pleural effusions, lymphedema, or hypoproteinemia are present.

Adult↗
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↗