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Biomedical subjects

A Dirisamer

Publications and source records attributed to A Dirisamer.

16 recordsLinked to original sources

[Anatomy and variants of hepatic segments, vessels, and bile ducts].

Knowledge of normal liver anatomy and its variants is indispensable for the radiologist. Accurate assessment of anomalies of the arterial, portal (venous), and biliary system and of liver segments using computed tomography is necessary for consultation with the surgeon and deciding on the therapeutic strategy. The multidetector CT is the most important tool for preoperative evaluation. Alternatively, MRI can be used with special regard to the biliary system (MRCP). This article reviews the most important variants of the liver detected with imaging modalities and their clinical relevance.

Bile Ducts, Intrahepatic↗

[MRT of the liver. Clinical significance of nonspecific and liver-specific MRT contrast agents].

The liver is a common site for various benign and malignant focal lesions. The initial modality for assessing liver lesions is ultrasound or CT. MRI with its superior soft tissue contrast offers multiple advantages over other imaging modalities. Contrast agents have been developed that increase the detection rate and provide more specific information in comparison to unenhanced techniques. In the mean time three classes are available for MR imaging of the liver: extracellular gadolinium chelates, hepatobiliary and reticulo-endothelia, superparamagnetic agents. We describe in this review the most common focal lesions, their diagnostic possibilities, and the imaging protocols. Clinical use of these contrast agents facilitates detection and differential diagnosis of focal liver lesions that may help to avoid invasive procedures such as biopsy for lesion characterization.

Chelating Agents↗

[Extended field-of-view sonography in Achilles tendon disease: a comparison with MR imaging].

PURPOSE: To evaluate the role of real-time extended field-of-view sonography (EFOVS) in symptomatic Achilles tendon disease in comparison with MR imaging (MRI). MATERIALS AND METHODS: Twenty-three symptomatic tendons were examined by conventional grayscale sonography, EFOVS and MRI, which served as the gold standard. RESULTS: The median tendon thickness in MRI was 7.8 mm (IQR 3.1) and correlated significantly to the results of EFOVS (7.0 mm, IQR 2; r = 0.74, P < 0.01). In total, MRI detected 24 lesions in 18 tendons and EFOVS 21 hypoechoic lesions in 15 tendons, corresponding to a sensitivity of 87.5 % and specificity of 100 %. The additional usage of conventional grayscale sonography improved sensitivity to 95.8 %. The median distance of the largest lesion to the calcaneal tuberosity was 10.4 mm (IQR 3.4) in MRI and 8.5 mm (IQR 5.1) in EFOVS (r = 0.64; P < 0.05). The sensitivity and specificity of EFOVS for the detection of a peritendinitis were 63.6 % and 66.7 %, respectively. Corresponding values for the detection of a bursitis were 68.8 % and 28.6 %. The additional usage of conventional grayscale sonography improved the specificity to 85.7 %. CONCLUSION: The combination of EFOVS and grayscale sonography has the potential to challenge MRI as the preferred imaging method in diagnosing symptomatic Achilles tendon disease, especially with respect to saving time and cost and the absence of any contraindications.

Achilles Tendon↗

[Three-dimensional digital rotation angiography for embolization therapy of uterine leiomyomas: first results].

PURPOSE: To evaluate three-dimensional rotational digital subtraction angiography (3D-RDSA) in the embolization of the uterine artery in the treatment of symptomatic uterine leiomyomas (fibroids). MATERIALS AND METHODS: Eight women with complex pelvic vessel anatomy caused by large fibroids were embolized using 3D-RDSA. The raw data were sent to an external workstation, and video files with a resolution of one image/3 degrees and a scan range of 180 degrees in a surface-shaded display mode were produced. The primary goal was to assess an image intensifier angulation for the optimal visualization of the origin of the uterine artery. In addition, the intervention parameters were compared with those of 48 patients with standard angiography. RESULTS: The analysis revealed no single angulation that can be recommended for standard angiography. No statistical differences were found between both groups concerning fluoroscopy time, dosage area product and amount of administered contrast medium (p > 0.05). CONCLUSION: It can be stated that 3D-RDSA is a feasible method that facilitates the catheterization of the uterine artery even in patients with complex pelvic vessel anatomy, with the potential to reduce the radiation exposure and the amount of administered contrast medium in future embolization therapy of symptomatic uterine fibroids.

Angiography↗

Colour and power Doppler sonography in symptomatic Achilles tendon disease.

The present trial focused on the exact role of colour and power Doppler sonography in Achilles tendinopathy and correlated these techniques with the clinical severity of the disease and with findings on grey-scale sonography. Twenty patients with in total 28 symptomatic Achilles tendons were included in this prospective trial. Additionally included were the asymptomatic tendons (n = 12) of patients and both tendons (n = 30) of fifteen controls. The pain score of Robinson - which ranges from 0 (strong severe pain) to 100 (asymptomatic) - was used to assess clinical severity of the disease. Both tendons of patients and controls were examined by a GE LOGIQ 9 trade mark scanner with a small-parts 14 MHz transducer. Grey-scale sonography detected in total 31 focal hypoechoic areas in 19 (68 %) of the 28 symptomatic tendons. Colour as well as power Doppler sonography detected blood flow in 14 (74 %) of the 19 tendons with focal hypoechoic areas. No blood flow was detected in the remaining symptomatic tendons (n = 14) and in the asymptomatic tendons of patients or in both tendons of controls. Colour and power Doppler sonography resulted in a specificity of 100 % and a sensitivity of 50 % for symptomatic Achilles tendinopathy. Patients with blood flow within the tendon had a significantly lower score according to Robinson than symptomatic patients without flow (P = 0.009). It is concluded that colour and/or power Doppler sonography are useful as an adjunct to grey-scale sonography in the examination of Achilles tendinosis, especially because the presence of blood flow is associated with stronger pain, discomfort and physical restriction.

Achilles Tendon↗

[CT and MRI characteristics of tumours of the temporal bone and the cerebello-pontine angle].

Tumours lesions of the temporal bone and of the cerebello-pontine angle are rare. This tumours can be separated into benign and malignant lesions. In this paper the CT and MRI characteristics of tumours of the temporal bone and the cerebello-pontane angle will be demonstrated. High resolution CT (HRCT) as usually performed in the axial plane are using a high resolution bone window level setting, coronal planes are the reconstructed from the axial data set or will be obtained directly. With the MRI FLAIR sequence in the axial plane the whole brain will be scanned either to depict or exclude a tumour invasion into the brain. After this,T2-weighted fast spin echo sequences or fat suppressed inversion recovery sequences in high resolution technique in the axial plane will be obtained from the temporal bone and axial T1-weighted spin echo sequences before and after the intravenous application of contrast material will be obtained of this region. Finally T1-weighted spin echo sequences in high resolution technique with fat suppression after the intravenous application of contrast material will be performed in the coronal plane. HRCT and MRI are both used to depict the most exact tumorous borders. HRCT excellently depicts the osseous changes for example exostosis of the external auditory canal, while also with HRCT osseous changes maybe characterized into more benign or malignant types. MRI has a very high soft tissue contrast and may therefore either characterize vascular space-occupying lesions for example glomus jugulare tumours or may differentiate between more benign or malignant lesions. In conclusion HRCT and MRI of the temporal bone are excellent methods to depict and mostly characterize tumour lesions and can help to differentiate between benign and malignant lesion. These imaging methods shall be used complementary and may have a great impact for the therapeutic planning.

Adenocarcinoma↗

Head and neck imaging with MDCT.

Multi-slice CT (MDCT) is rapidly becoming the new standard in radiological imaging. Although its advantages in cardiovascular, thoracic and abdominal imaging are evident, the extent of its usefulness for imaging the head and neck has yet to be clarified. Because of the shorter examination time motion artifacts are reduced, phonation-studies are possible. Due to the thin-slicing and nearly isotropic multiplanar reconstruction (MPR) examination in only one plane is necessary, saving both time and radiation exposure. The shorter examination requires the use of higher concentrated contrast medium (400 mg of iodine/ml). The use of such a contrast medium produces a higher degree of contrast enhancement and provides a 5-10% higher contrast between the surrounding normal and pathological tissue, but is more time critical. MPRs are easily done in any plane within seconds and enables also three-dimensional visualization, what helps in the use of minimal invasive therapy, training and teaching and provides a way of handling the hundreds of images acquired during scanning.

Carcinoma, Squamous Cell↗

Treatment of extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) with mitoxantrone, chlorambucil and prednisone (MCP).

BACKGROUND: Mucosa-associated lymphoid tissue (MALT) lymphoma is a relatively common type of lymphoma arising in various tissues throughout the human body. Currently, there is no standard chemotherapy for advanced stage MALT lymphoma. This has prompted us to retrospectively analyse our experience with the MCP regimen (mitoxantrone, chlorambucil and prednisone) in patients with MALT lymphoma. PATIENTS AND METHODS: Patients with histologically verified MALT lymphoma undergoing chemotherapy with MCP were evaluated retrospectively. The MCP regimen consists of mitoxantrone 8 mg/m(2) intravenously on days 1 and 2, chlorambucil 3 x 3 mg/m(2) per os (p.o.) on days 1-5 and prednisone 25 mg/m(2) p.o. on days 1-5. Information analysed included localisation of the lymphoma, clinical stage, pretreatment, number of chemotherapy cycles administered, toxicity, response to treatment, follow-up time, relapse and survival. RESULTS: A total of 15 patients (six females and nine males aged between 34 and 88 years) with histologically ascertained MALT lymphoma undergoing treatment with the MCP regimen were identified from our records. Ten patients had extragastric lymphoma, while five patients suffered from gastric MALT lymphoma. All patients were chemotherapy-naïve, while two had been locally irradiated before application of MCP for recurrent disease. A total of 74 cycles was administered to our patients, with a median number of five cycles per patient. Eight (53%) patients achieved complete remission, six (40%) patients partial response and only one (7%) patient had progressive disease. Subjective tolerance was excellent, and toxicities were mainly haematological, including granulocytopenia World Health Organisation grade 3 and 4 in three patients each. In two patients, this was accompanied by single episodes of uncomplicated herpes simplex infection. At the time of analysis, all patients are still alive. No relapses have occurred after a median follow-up time of 16 (range 12-29) months. CONCLUSIONS: Our data suggest that MCP is an effective and well-tolerated regimen for treatment of patients with MALT lymphoma irrespective of localisation. Judging from our data, MCP also appears to be a feasible regimen in elderly patients.

Administration, Oral↗

Feasibility study of NeoMend, a percutaneous arterial closure device that uses a nonthrombogenic bioadhesive.

OBJECTIVE: The aim of this prospective single-center phase I feasibility study was to investigate the safety and efficacy of a novel vascular sealing device, the NeoMend Arterial Closure Device, that uses a bioadhesive after percutaneous endovascular procedures. SUBJECTS AND METHODS: In 26 consecutive patients, the sealing device was deployed at the femoral artery access site immediately after a catheterization procedure using a 6-French (1.91-mm) sheath. Patients were followed up at 24 hr with Doppler sonography of the treated femoral artery puncture site, and at 1 week and 1 month by a telephone interview. RESULTS: Successful hemostasis was achieved with the NeoMend Arterial Closure Device in 21 (88%) of 24 patients. One major complication required surgery: formation of puncture site hematoma and pseudoaneurysm 3 days after the intervention after successful primary hemostasis. Two device failures required crossover to manual compression, which was done without further complications. The mean time to hemostasis was 7.0 +/- 4.5 min. Mean time to ambulation was 6.0 hr. At follow-up, the patients did not report any puncture-site-related complaints. Doppler sonography of the puncture sites revealed three insignificant hematomas of less than 20 mL and patent common femoral vessels without stenoses. CONCLUSION: The NeoMend Arterial Closure Device appears to achieve rapid hemostasis with the potential of early ambulation after arterial punctures with a 6-French sheath. The device is an alternative in situations in which suture- or collagen-mediated devices show high complication rates.

Adult↗

[Change in process management by implementing RIS, PACS and flat-panel detectors].

Implementation of radiological information systems (RIS) and picture archiving and communicating systems (PACS) results in significant changes of workflow in a radiological department. Additional connection with flat-panel detectors leads to a shortening of the work process. RIS and PACS implementation alone reduces the complete workflow by 21-80%. With flatpanel technology the image production process is further shortened by 25-30%. The workflow-steps are changed from original 17-12 with the implementation of RIS and PACS and to 5 with the integrated use of flatpanels. This clearly recognizable advantages in the workflow need an according financial investment. Several studies could show that the capitalisation-factor calculated over eight years is positive, with a gain range between 5-25%. Whether the additional implementation of flatpanel detectors results also in a positive capitalisation over the years, cannot be estimated exactly, at the moment, because the experiences are too short. Particularly critical are the interfaces, which needs a constant quality control. Our flatpanel detector-system is fixed, special images--as we have them in about 3-5% of all cases--need still conventional filmscreen or phosphorplate-systems. Full-spine and long-leg examinations cannot be performed with sufficient exactness. Without any questions implementation of integrated RIS, PACS and flatpanel detector-system needs excellent training of the employees, because of the changes in workflow etc. The main profits of such an integrated implementation are an increase in quality in image and report datas, easier handling--there are almost no more cassettes necessary--and excessive shortening of workflow.

Austria↗

[Apophyseal damage in adolescent athlete].

The increasing demands on the adolescent athlete in high performance sports puts high biomechanical stress on the growing structures of the active and passive locomotor system. The "growing factor" itself increases stretching forces on tendon insertions, which are often overloaded when a physical demanding sport is performed additionally. The apophysis is an ossification nucleus near the tendon insertion, which appears before the growing age resumes and these apophysis finally fuses with the adjacent bone. The tensile forces from vigorous sports activity leads to a chronic or acute avulsion of the ossifying tendon insertion. The radiological appearance of this apophyseal damage with ossification and osteolytic processes is sometimes difficult with respect to differential diagnoses. Apophyseal impairment is associated with pain, tenderness to palpation and decreased muscle function. If it is not diagnosed and treated properly it can lead to end of career in many adolescent athletes.

Adolescent↗

Prostanoids in the treatment of intermittent claudication--a meta-analysis.

BACKGROUND: Numerous studies have established the efficacy of prostanoids in PAD stages III and IV, but the role of prostanoids as an alternative or additive treatment in patients suffering from PAD II is less clear. To resolve this uncertainty we performed a meta-analysis of all randomised controlled studies analysing effects of prostanoids in patients suffering from intermittent claudication. METHODS: 96 studies have been screened by computerised searches of MEDLINE and EMBASE. Relevant studies were pooled in Cochrane's Review-manager 4.1. RESULTS: 19 studies were included for further analysis. Five studies could not be pooled for analysing walking distances, because standard deviations were not stated. Eight studies compared effects of any prostanoid i.v. vs. placebo. In total 557 patients (281/276) were included for analysis of painfree--walking distance (PFWD) and 519 patients (262/257) for analysis of maximum walking distance (MWD). Prostanoids compared to placebo significantly improved mean PFWD by 28% (7%-49%, P = 0.008) and mean MWD by 30% (11%-50%, P = 0.002). At least one adverse reaction was reported from 39.6% of the patients treated with prostacyclin and its analogues and from 13.7% of the patients treated with prostaglandin E1. CONCLUSION: Patients suffering from intermittent claudication benefit from administration of prostaglandin E1 by a significant improvement of their walking capacity.

Arterial Occlusive Diseases↗

[The role of chest X-rays in the diagnosis of thoracic aortic aneurysms].

OBJECTIVE: To evaluate the role of routine chest radiographs in the diagnosis of thoracic aortic aneurysms (TAA). METHODS: An electronic full-text search was performed in our radiological information system for all patients who underwent chest radiograph under standard conditions between 1998 and 2000 and who had suspected widening or aneurysm of the thoracic aorta as a diagnosis. Computed tomography (CT) of the thorax was used as the gold standard and had to be performed within a period of 30 days. Two independent and blinded observers evaluated different morphologic and morphometric parameters in the diagnosis and correlated the results with those of CT. RESULTS: 28 patients were included in the present trial. With almost perfect interobserver correlation (r = 0.95) both investigated morphometric parameters correlated well (r = 0.85 and 0.83) with the diameter of the aorta as evaluated with CT. While a low subjective over-all probability for TAA had a negative predictive value of 100 %, we found that, despite an almost perfect interobserver variability (Kappa > 0.8), none of the investigated morphologic parameters (discrepancy between the ascending and descending aorta, displacement of the trachea to the right and caudal displacement of the left main bronchus) was significantly correlated with the final diagnosis. CONCLUSION: The investigated morphometric parameters help to estimate the diameter of the aorta in the arch and in the descending section, but none of the morphologic criteria can be used for the diagnosis of TAA.

Aortic Aneurysm, Thoracic↗

Lipoprotein(a) as a potent risk indicator for early cardiovascular disease.

AIM: Elevated levels of lipoprotein (a) [Lp(a)] are associated with increased cardiovascular risk in adults. It is not known whether Lp(a) elevation can be regarded as an additional risk factor even in children and adolescents. Therefore the purpose of this study was to compare the serum concentrations, distribution and frequency of Lp(a) and lipids of children and adolescents with premature parental and/or grandparental cardiovascular disease (CVD) with controls. METHODS: 103 children and adolescents, aged 6-18 y, from families with premature CVD in a parent and/or grandparent, i.e. before the age of 55 y, and 103 controls were estimated for lipids and Lp(a). RESULTS: Mean levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and Lp(a) were significantly higher in the risk than in the control group. Median Lp(a) levels were 20 (10-61.5) mg dl(-1) in the risk subjects, and 15 (6-26.5) mg dl(-1) in the control subjects (p = 0.005). Mean TC and LDL-C concentrations of the risk group compared with the control group were 211 mg dl(-1) (5.5 mmoll(-1)) versus 165mg dl(-1) (4.3mmol l(-1)) (p < 0.0001), and 140 mg dl(-1) (3.6 mmol l(-1)) versus 101 mg dl(-1) (2.6 mmol l(-1)) (p < 0.0001), respectively. CONCLUSION: It may be important to estimate plasma Lp(a) levels in progeny with a familial history of premature CVD, because it seems possible to identify those subjects who are at greater risk for later CVD either with or without elevated LDL-C levels.

Adolescent↗

[Temporary and permanent vena cava filter for prevention of pulmonary embolism].

Inferior vena cava filters have been used for prophylaxis of pulmonary embolism since the end of the sixties. Complication rates depend on the types of filters used and are reported to be 2% with the Guenther-Filter and 21% with the Titanium-Greenfield-Filter. Depending on the exact indication both filter types are useful instruments for the prevention of pulmonary embolism.

Equipment Design↗