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U K Teichgräber

Publications and source records attributed to U K Teichgräber.

At least 19 recordsLinked to original sources
PubMed2003

[Prospective cost-benefit analysis of a fully digitized working environment in an ultrasound division applying process simulation].

PURPOSE: Quantification of expected savings of work load and personnel costs after implementation of a digital infrastructure in an ultrasound division of a radiology department. MATERIALS AND METHODS: The work flow of an ultrasound examination was simulated by means of a computer model. After validation, the computer model was modified to represent a work flow with PACS, electronic patient record, and automatic scheduling. The simulation results of work load, equipment utilization, and personnel costs were compared for both scenarios. RESULTS: The total number of work steps was reduced from 29 in the conventional scenario to 14 work steps in the scenario with digital infrastructure. The work load of administrative activities decreased by 89 % whereas the work load of activities directly related to the ultrasound examination remained unchanged. The productive personnel costs declined from euro; 24 to euro; 16 per examination. The gross labor costs declined from euro; 33 to euro; 20 per examination. Given unchanged equipment and number of patients, the required number of physicians can be reduced from 3 to 2 and that of technicians from 2 to 1 by use of a digital infrastructure. CONCLUSION: A digital infrastructure possesses a great potential for efficiency provided that it is implemented comprehensively and the work flow is adapted utilizing the capabilities of automation in all work processes.

Automation↗
PubMed2001

Anatomical variations in the internal jugular veins of cancer patients affecting central venous access. Anatomical variation of the internal jugular vein.

PURPOSE: Establishing a reliable central venous access is an important procedure in clinical haematology and oncology. The purpose of this study was to determine how anatomical variations in the internal jugular vein (IJV) and its position in relation to the common carotid artery (CCA) in cancer patients affects external landmark puncture. PATIENTS AND METHODS: In 113 patients with haematological or oncological diseases we examined sonographically potential target regions for placement of a central catheter via the IJV. RESULTS: 36% of our patients showed anatomical variations in the IJV and surrounding tissue. CONCLUSIONS: External landmark puncture may be difficult in a considerable number of patients since the IJV might not be situated in the presumed location anteriorly or laterally to the CCA, or a normal lumen may not be present in approximately 1/3 of cancer patients. This study supports the use of ultrasound-guided techniques for central venous catheters particularly in haematological and oncological patients.

Adult↗
PubMed2001

The role of Doppler velocity histograms of hepatic veins in early detection of cirrhotic changes of the liver parenchyma.

AIM: In a prospective study we measured the velocity ranges of the Doppler Velocity Histogram (DVH) of the hepatic venous system at two levels (-3 dB and -6 dB) below the maximum power level of the Doppler wave in order to investigate if that allows a higher selectivity between the Doppler tracings in hepatic veins of patients with liver cirrhosis and healthy subjects. METHODS: The DVH was measured in 23 healthy subjects and 31 patients with liver cirrhosis of different etiologies at power levels of -3 and -6 dB in the right and middle hepatic vein after an overnight fast. The DVH measurements were performed at the maximum of phase I of the hepatic venous flow in which we assessed the Peak-, Mode-, Mean-Value, and the velocity range (bandwidth). RESULTS: At both power levels the bandwidth (BW) of the DVH in the right and middle hepatic vein was significantly higher in cirrhotics than in healthy subjects (-3 dB: RHV: p = 0.048, MHV: p = 0.006; -6 dB: RHV and MHV: p < 0.0005). The selectivity between healthy subjects and cirrhotics is higher at the -6 dB level than at the -3 dB level. CONCLUSION: The DVH-measurement is a useful additional device in early sonographic detection of cirrhotic liver parenchyma changes. DVH-velocity range measurements at a level of -6 dB below the maximum power level reveal a better selectivity between healthy subjects and cirrhotic patients than measurements at the -3 dB level. It is recommendable to perform velocity range measurements at different power levels within a single frozen image.

Adult↗
PubMed2001

[MRI diagnosis of injuries and diseases of peroneal tendons].

Injuries of the peroneus tendons are common and both the athlete and the older population are at risk. MR imaging is a useful technique for revealing injuries of the peroneus tendons as well as showing anatomic factors associated with these lesions. This article reviews clinical factors and MR imaging characteristics of injuries of the peroneus tendons.

Ankle Injuries↗
PubMed2000

[Ultrasonographically guided puncture technique for central venous vessels as a one-person technique].

AIM: The traditional anatomic landmark technique usually allows a rapid and easy central venous access but this technique is not always successful and can be associated with severe complications. We developed an ultrasonically guided one-operator-catheterization technique whereas a second operator to place and hold the ultrasound transducer is not necessary. METHOD: The catheterisation technique consists of 3 functional components: the swivel arm, the ultrasound unit and the conventional Seldinger central venous catheterization technique. As swivel arm we used a device with a 300 mm column with a 700 mm span attached to ultrasound unit. There were 234 catheterizations of the internal jugular vein performed in the period of January 1999 to July 1999. The indication and complication rate for the catheterization procedure was documented. RESULTS: There were 2 plexus irritations and 1 hematoma observed in all performed catheterization procedures which remained without therapeutic consequences. CONCLUSION: Once the decision for central venous access has been made the safest technique should be applied. The ultrasonically guided catheterization technique allows a fast, safe and convenient central venous access for our patients.

Catheterization, Central Venous↗
PubMed1999

The spectrum of imaging in Currarino triad.

The aim of this study was to evaluate the spectrum of findings and the efficacy of different imaging modalities in order to formulate recommendations for diagnostic imaging of Currarino triad (ASP syndrome), including screening of relatives. The imaging films of five female patients (age range 6 weeks to 12 months) were analysed retrospectively. The studied material consisted of US and MRI of the lower spine (5 patients each), lumbosacral plain radiography (4 patients), contrast enema (4 patients), urinary US (2 patients), genitography (1 patient) and myelo-CT (1 patient). Depiction of pathological findings with different imaging modalities was reviewed and validated with special respect to their demonstrability by US. Ultrasonography detected the sacral bony defect as well as the presacral pathology (meningocele and/or tumour) and thereby gave the basic diagnosis in all of the cases. It also depicted tethered cord and urinary tract abnormalities correctly. Magnetic resonance imaging gave a more distinct visualization of pre- and intraspinal pathology with additional demonstration of intraspinal lipoma in two cases. Regarding anorectal and genital malformations, radiographic contrast agent studies had been used in all patients. Two blind-ending retrorectal fistulas, depicted by enema, were missed by MRI. Patients with congenital or early infancy obstipation, anorectal malformations and complex urinary tract malformations should have spinal and pelvic sonography first. A plain film of the sacrum is recommended in equivocal cases. The need for MRI and contrast agent studies depends on the individual pathology, whereas presently MRI has made further radiographic imaging increasingly dispensable. A screening program with lumbosacral US or plain radiography for families with Currarino triad should be obligatory.

Abnormalities, Multiple↗
PubMed1999

[Automated speech recognition for the generation of medical records in computed tomography].

PURPOSE: A study was performed to compare the performance of automatic speech recognition (ASR) with conventional transcription. MATERIALS AND METHODS: 100 CT reports were generated by using ASR and 100 CT reports were dictated and written by medical transcriptionists. The time for dictation and correction of errors by the radiologist was assessed and the type of mistakes was analysed. The text recognition rate was calculated in both groups and the average time between completion of the imaging study by the technologist and generation of the written report was assessed. A commercially available speech recognition technology (ASKA Software, IBM ViaVoice) running on a personal computer was used. RESULTS: The time for the dictation using digital voice recognition was 9.4 +/- 2.3 min compared to 4.5 +/- 3.6 min with an ordinary Dictaphone. The text recognition rate was 97% with digital voice recognition and 99% with medical transcriptionists. The average time from imaging completion to written report finalization was reduced from 47.3 hours with medical transcriptionists to 12.7 hours with ASR. The analysis of misspellings demonstrated (ASR vs. medical transcriptionists): 3 vs. 4 for syntax errors, 0 vs. 37 orthographic mistakes, 16 vs. 22 mistakes in substance and 47 vs. erroneously applied terms. CONCLUSIONS: The use of digital voice recognition as a replacement for medical transcription is recommendable when an immediate availability of written reports is necessary.

Algorithms↗
PubMed1999

[Project graph technique for time management in abdominal ultrasound evaluations].

PURPOSE: German insurance companies are cutting down the time required for ultrasound examinations. To determine the minimal examination time to perform an ultrasound examination a project graph technique was applied. MATERIALS AND METHODS: Time measurements of abdominal ultrasound examinations were performed by two independent observers. The different jobs for the performance of an ultrasound examination were determined and the critical pathway method applied. The total available time for abdominal ultrasound examinations (leeway) was determined, the minimal time to perform each job was measured and the critical time required for the procedure was calculated. RESULTS: 14 different jobs were identified to complete one abdominal ultrasound examination. The project graph displayed the shortest possible time of 24 minutes to perform an ultrasound examination. The pure ultrasound exam without colour Doppler examination was 6 minutes ("hands on the ultrasound probe"). The jobs performed by the physician were fully within the critical period. In consequence, the physician had no leeway or time lag in relation to a total time of 24 minutes for an ultrasound examination, whereas by contrast the nurse has a total leeway of 7.5 minutes. CONCLUSIONS: The applied project graph technique is an effective instrument for the purpose of quality management for hospitals as well as in private practice. The workflow and actions necessary to perform a treatment or examination can be analysed. Human resources management and cost planning should be performed on the basis of project graphs.

Abdomen↗
PubMed1999

Differential diagnosis of lymph node lesions. A semiquantitative approach with power Doppler sonography.

RATIONALE AND OBJECTIVES: To assess the value of power Doppler for distinguishing reactive from malignant lymph node disease. METHODS: In a prospective study, 48 untreated patients with palpable cervical lymph node enlargement (n = 211) underwent examination with power Doppler sonography. The perfusion sites were subdivided into three groups: central, peripheral, and hilar perfusion. In addition, the authors qualified the intensity of perfusion using a semiquantitative scale from 0 (no perfusion) to III (high perfusion). Finally, the overall perfused lymph node area was measured and the percentage of perfused nodal area was calculated. RESULTS: Power Doppler sonography showed perfusion in 183 of 211 lymph nodes. Histologic examination revealed 67 reactively enlarged lymph nodes, 72 metastases, and 44 lymphomas. Reactively enlarged lymph nodes showed characteristically intense hilar perfusion (82.1%), whereas nodal metastases exhibited mainly peripherally located flow (84.7%) of grade intensity I to III. Lymph nodes invaded by malignant lymphoma were highly perfused, displaying color signals in the center as well as in the nodal periphery (90.9%). CONCLUSIONS: The perfusion patterns of lymph nodes provide useful additional information in the differential diagnosis of cervical lymphadenopathy.

Adolescent↗
PubMed1997

[Duplex ultrasound characterization of hepatic vein blood flow in healthy probands].

PURPOSE: To characterise and standardise hepatic venous flow during the respiratory cycle in all three hepatic veins and to determine the most adequate measurement area within the vessel. METHOD: In 25 healthy subjects duplex Doppler measurements were performed of the right (RHV), middle (MHV) and left (LHV) hepatic vein. In full inspiration, mid-inspiration and expiration the maximum flow velocities of all three hepatic venous flow components (phase 1 to 3) were measured and a systolic to diastolic (S/D) ratio was determined. RESULTS: In full inspiration there was a decrease of the maximum flow velocities compared to mid-inspiration (p = 0.0001). In expiration there was an increase of the maximum flow velocities (p = 0.0005). The maximum flow velocities of the MHV in mid-inspiration were -0.21 +/- 0.019 m/s (phase 1), -0.16 +/- 0.016 m/s (phase 2) and 0.08 +/- 0.011 m/s (phase 3). The S/D ratio decreases on inspiration and increases on expiration. The maximum flow velocities of the LHV differed significantly from those of the RHV and MHV. The measurements of the RHV and MHV were both reliable. Measurements from central to peripheral within the hepatic veins showed a decrease in maximum flow velocities. CONCLUSION: For standardisation of hepatic venous flow measurements the respiratory state must be determined. The most adequate area for duplex Doppler ultrasound measurements is situated about one or two centimetres from the orifice of the vena cava.

Adult↗
PubMed1997

A sonographically guided technique for central venous access.

OBJECTIVE: The internal jugular vein (IJV) is an important access to the central venous system. We compared sonographically guided technique with the traditional anatomic landmark technique for IJV catheterization. SUBJECTS AND METHODS: In a prospective randomized trial, 100 patients underwent routine catheterization of the IJV (50 patients in the sonography group and 50 patients in the anatomic landmark group). Access time, failure rates, and complication rates were evaluated. In addition, the physicians' number of years of experience with catheter insertion was recorded. RESULTS: Access time was markedly shorter with the sonographically guided technique (mean, 15.2 sec; range, 8-76 sec) than with the anatomic landmark technique (mean, 51.4 sec; range, 3-820 sec) (p = .001). The failure rate was significantly lower with the sonographically guided technique (p = .002). Complications were fewer with the sonographically guided technique (neck hematoma, 2% versus 10%; plexus irritation, 4% versus 6%; carotid artery puncture, 0% versus 12%). We found that the number of years of postgraduate clinical training was greater in the group of physicians using the anatomic landmark technique. CONCLUSION: The sonographically guided technique is associated with less risk and less inconvenience for patients, especially critically ill patients, for whom the technique provides fast, safe, and easy IJV catheterization.

Catheterization, Central Venous↗
PubMed1997

Effect of respiration, exercise, and food intake on hepatic vein circulation.

Since the effects of respiration, nutrition, and exercise on blood flow in the hepatic vein are not well understood, the objective of this study was to determine the hemodynamic influence of these factors on hepatic venous circulation using Doppler ultrasonographic tracings. The venous blood flow of the middle hepatic vein was determined during arrested full inspiration, midinspiration, and expiration in 25 healthy subjects. The maximum velocity and the systolic-to-diastolic ratio of the blood flow were measured. The portal vein blood flow velocity was measured in 20 volunteers before and after food intake. The portal vein blood flow and the hepatic vein flow velocity were examined in eight volunteers after exercise. During inspiration, maximum blood flow velocity of the hepatic veins decreased compared to midinspiration (P < 0.001). With expiration the maximum velocity increased (P < 0.001). After food consumption, there was no change in the velocity of the hepatic veins, but the portal vein blood flow increased (P = 0.041). After physical exercises, the maximum velocity of the hepatic venous flow increased, on average, about 148% (P = 0.01), and the portal vein blood flow decreased about 44% (P = 0.027). To achieve standard measurements of hepatic venous blood flow, the state of respiration and physical exertion should be established. The nutritional status had only a minor influence on hepatic vein measurements.

Adult↗