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A Tschammler

Publications and source records attributed to A Tschammler.

At least 19 recordsLinked to original sources
PubMed2005

[Individualized dose requirement for spiral-CT analysis of the abdomen].

PURPOSE: To search for individualized scan protocols that provide adequate diagnostic information with minimal radiation exposure for abdominal CT in adults. MATERIAL AND METHODS: Beginning with standard settings (120 kVp, 200 mA, 0.75 s, CTDI (w = 11.7 mGy)), which are in the lowest quartile of the actual German radiation dose survey, 119 adults were examined using a single-row detector helical CT with 8 mm collimation and a pitch of 1.5. The individualized scan protocol was defined by repeating the reference scan up to 3 times with different radiation doses following a predefined iteration scheme. The image qualities with standard dose and with individualized dose were assessed independently by 3 radiologists blinded to the exposure parameters. The individualized dose was correlated with the diameter of the patients. RESULTS: The patient diameters varied from 16 to 35 cm and correlated with individualized radiation doses CTDI (w) from 6.4 to 17.6 mGy. We found an exponential correlation (y = 52.3 x e (0.05 x); r(2) = 0.48; p < 0.001) between required tube current (mA) and a. p. diameter (cm) in the epigastric region in adults. CONCLUSION: Maintaining constant exposure parameters results in unnecessary radiation exposure in patients with a diameter of less than 27 cm measured in anterior-posterior direction in the epigastric area. The radiation exposure in adult abdominal CT can be reduced up to 45 % by individualized selection of the tube current without adversely affecting diagnostic performance.

Adult↗
PubMed2005

A case of metastasizing invasive hydatidiform mole. Is less--less good? Review of the literature with regard to adequate treatment.

BACKGROUND: Patients with invasive hydatidiform moles (IHM) have a good prognosis. Even if disease has spread, monocytostatic treatment might be sufficient if the diagnosis has been histologically confirmed. Established classifications divide gestational trophoblastic disease (GTD) including choriocarcinoma into cases with "high" and "low" risk. Without respect to histology "high-risk" cases are recommended to obtain polychemotherapy. CASE: A 40-year-old nullipara underwent hysterectomy for persistent vaginal bleeding after she had already been treated with curettage for hydatidiform mole. An IHM was pathohistologically confirmed. There were no signs of pulmonary spread or other metastases at the time of surgery. Postsurgically persistent beta-hCG levels lead to thorough staging, which revealed multiple pulmonary metastases and a vaginal metastasis. Despite metastasizing GTD with poor prognosis criteria she was treated with single agent therapy. Eight cycles of two weekly methotrexate (MTX) were administered. All sites of metastases responded and our patient is still fine after one year of follow-up. CONCLUSION: With respect to this and other reports monochemotherapy can be a reasonable primary treatment for metastatic IHM.

Adult↗
PubMed2002

Differential diagnosis of lymphadenopathy: power Doppler vs color Doppler sonography.

Our objective was to compare color and power Doppler sonography of superficial lymph nodes. One hundred ninety-three lymph nodes in 161 patients were assessed by color and power Doppler sonography using standardized settings. We tested which modality displayed more intranodal vessels and checked if these differences would have altered the diagnosis. Additional vessels were seen by color Doppler sonography in 18 nodes and by power Doppler sonography in 58 nodes. Amongst those nodes were 15 nodes which showed no vascularization in color Doppler sonography and 23 nodes with only few intranodal flow signals; however, the better sensitivity of power Doppler sonography had no impact on the diagnosis in 42 of 58 nodes. Diagnostic confidence was increased in 7 nodes which showed normal vessels only in power Doppler sonography, although missing flow signals were defined as a benign finding. Pathological vessels were displayed only by power Doppler sonography in 9 nodes, but 6 of these 9 results proved to be false positive. Power Doppler sonography displays more intranodal flow signals than color Doppler sonography, but the diagnostic impact is low because of an increased risk of false-positive results.

Adult↗
PubMed2002

Metallic stents and plastic endoprostheses in percutaneous treatment of biliary obstruction.

BACKGROUND: In the light of the clinical controversy whether metallic stents or plastic endoprostheses should be used in the percutaneous treatment of biliary obstruction we retrospectively evaluated our experience with both drainage-systems. METHODS: 71 patients (mean age 68 +/- 12 years) underwent a total of 81 interventions and received either plastic endoprostheses (11.5 or 12 French diameter; N = 57/81) or metallic stents (N = 24/81). RESULTS: Drainage insertion was technically successful in all of the 71 patients. There was no procedure-related mortality, but a 30-day mortality of 15 % (N = 11). Overall, 27 complications occurred in 81 interventions with a statistically significant higher complication-rate in plastic endoprostheses (39 %; N = 21/54) compared to metallic stents (22 %; N = 6/27). The average patency of the drainage-systems was 166 +/- 341 days (range 1-2,705 days) and did not differ significantly between the drainage-subtypes. Incidence of complications and a further increase in serum bilirubin following intervention was associated with a higher drainage occlusion-rate and reduced survival, irrespective of the drainage-system used. CONCLUSIONS: Percutaneous transhepatic treatment of biliary obstructions with internal drainages is a reliable therapy. The overall complication-rate of metallic stents was lower compared to plastic endoprostheses; however, no significant differences were found with respect to drainage patency or success-rate.

Adult↗
PubMed2001

Optimization of automatic bolus tracking for timing of the arterial phase of helical liver CT.

The aim of this study was to optimize bolus tracking for timing of the arterial phase of biphasic helical liver CT and to compare optimized bolus tracking to a standard delay. One hundred fifty patients were examined with six protocols: 5- or 10-s delay after triggering at a threshold of 50 or 75 or 100 HU enhancement in the aorta at the origin of the celiac arteries after injection of 120 ml contrast material at 3 ml/s. Optimal arterial enhancement was defined as 20-30% of hepatic enhancement in portal venous phase. Another 50 patients were examined with the optimized protocol and compared to 50 gender- and age-matched patients who underwent a 25-s standard delay. A 10-s delay after the 75-HU threshold resulted in the most patients with an optimal arterial phase (p < 0.01). Thirty-one of 75 patients examined with this protocol showed optimal early liver enhancement. Bolus tracking compared with standard delay revealed only a trend for a difference (p = 0.07). The outcome of automatic bolus tracking differs depending on the protocol used; however, optimal arterial phase imaging was seen in only 41% of patients, indicating only a trend for superior timing compared with a standard delay.

Adolescent↗
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

Galactography and exfoliative cytology in women with abnormal nipple discharge.

OBJECTIVE: To evaluate galactography and cytology in women with nipple discharge without clinical or mammographic evidence of cancer. METHODS: During a 12.5-year period, 384 women (15-85 years, mean age 47.5 +/- 14 years) were referred for galactography and smear cytology for recent onset of spontaneous, non-milky nipple discharge. Patients with clinical or mammographic evidence of tumor underwent excisional biopsy directly. Among 314 galactograms, 189 [60.2%; 95% confidence interval (CI) 54.5%, 65.6%] biopsies were recommended. A further 11 patients were scheduled for biopsy because of mammography or cytology. RESULTS: Sixteen of 182 biopsied patients had malignancies (8.8%; CI 5.3%, 14.1%). Combined rate of papillomas, papillomatous proliferation, and malignant tumors was 59.9% (109 of 182; CI 52.4%, 67.0%). Biopsy was malignant in three of 56 women (5%) with nonhemorrhagic discharge and in 13 of 97 (13%) with hemorrhagic discharge (P =.26). Exfoliative cytology revealed 11 false-negatives, four false-positives, five true-positives, and 153 true-negatives (sensitivity 31.2%, CI 11%, 58%; specificity 97.4%, CI 93%, 99%). In ten of 158 patients (6.3%) with suspicious galactography, cancer was found by biopsy. Sensitivity of galactography for malignancy was 83% (CI 51.6%, 97.9%) and specificity was 41% (CI 35.2%, 46.5%). Galactographic sensitivity for any (benign or malignant) neoplasm was 94% (93 of 99; CI 87%, 98%) and specificity was 55% (119 of 215; CI 48%, 62%). Half of the cancers were detected exclusively by galactography. CONCLUSION: Cytology is helpful when positive and galactography localizes the source of discharge. Biopsy is indicated when palpation, mammography, cytology, or galactography is suspicious.

Adolescent↗
PubMed2001

Compression repair of ruptured pseudoaneurysms guided by color Doppler ultrasonography: report of two cases.

Noninvasive treatment of ruptured postcatheterization pseudoaneurysms is rare. We report the use of ultrasonographically guided compression repair for the treatment of ruptured pseudoaneurysms in 2 cases. To ensure the immediate stop of bleeding, more compression was applied than for nonruptured pseudoaneurysms, regardless of flow in the femoral artery or vein, thus maximizing the effectiveness of this therapy. With this method, complete thrombosis of the pseudoaneurysm could be achieved in less than 30 minutes. In both cases, ultrasonographically guided compression repair was faster than the time needed to prepare an operating room for surgical treatment. In follow-up examinations, no recurrences or further complications were detected. Ultrasonographically guided compression repair can be used for noninvasive treatment of ruptured pseudoaneurysms in some cases, provided that more compression than indicated for nonruptured pseudoaneurysms is applied. Further clinical experience with more patients will be necessary to determine the exact benefits and possible limitations.

Aged↗
PubMed2000

Pathological angioarchitecture in lymph nodes: underlying histopathologic findings.

Pathologic changes of the intranodal angioarchitecture, as displayed by colour Doppler sonography, were used in recent studies to predict malignant infiltration of superficial lymph nodes. We searched for the underlying histopathologic findings in a prospective study including 100 lymph nodes in 86 patients. In the histopathologic specimens, we evaluated tumour infiltration, distribution of intranodal vessels, hilar structures, thickness of the capsule and tissue alterations (necrosis, sclerosis, lipo-/fibromatosis). Using the only prospectively tested classification, a pathologic angioarchitecture was described as displacement, aberrant course, avascular foci or subcapsular vessels. Testing these four criteria by multivariate regression analysis, the most important correlations were found between the following pairs of sonographic and histopathologic findings: displacement with perinodal tumour spread, aberrant vessels with intranodal sclerosis, avascular foci with intranodal necroses and subcapsular vessels with intranodal necroses. In conclusion, the criteria describing a pathologic angioarchitecture correlate with histopathologic findings that are frequently seen in malignant lymph nodes.

Adolescent↗
PubMed2000

Predictive value of galactographic patterns for benign and malignant neoplasms of the breast in patients with nipple discharge.

The purpose was to identify features of malignant and non-malignant neoplastic breast disease on galactography and to estimate their predictive value. This is the largest reported study correlating galactographic morphological patterns with histopathology and the only blinded study. The study included 351 consecutive galactograms and 161 breast biopsies performed in patients with nipple discharge over a 10-year period. Three radiologists, blinded to clinical data and histological results, re-evaluated 158 previously performed galactograms of patients who had undergone excision biopsy. Extravasation or incomplete filling precluded reading in 9.5% of examinations. Among the remaining 143 examinations there were 11 cancers (7.7%), 56 papillomas (39.2%), 19 cases of intraductal papillomatous proliferation (13.3%), 55 cases of fibrocystic or secretory disease (38.5%) and two normals. A "filling defect/cut-off" pattern (n = 90) was found in 6 cancers (6.7%) and 58 cases of papilloma or papillomatous proliferation (64.4%). A "leafless tree" pattern was found only in benign cases (n = 12; 8.4%). In 32 of 143 cases (22.4%) a "ductal ectasia" pattern was present, in one case of which (3.1%) cancer was found. Cancer was identified in two of four cases with an "architectural distortion" pattern. Cancer is rare in patients with nipple discharge. A tendency towards a lower incidence of cancer associated with the "ductal ectasia" and "leafless tree" patterns was found. No statistical evidence was found to indicate that galactography provides an effective prospective diagnosis of malignancy. However, an abnormal galactogram strongly correlated (p < 0.001) with the presence of a breast neoplasm when both benign and malignant tumours were considered. The most important role played by galactography is in the localization of breast neoplasms and in the choice of appropriate surgical therapy.

Adult↗
PubMed2000

Is the appearance of microcalcifications on mammography useful in predicting histological grade of malignancy in ductal cancer in situ?

It has been proposed that the grade of malignancy of ductal carcinoma in situ (DCIS) of the breast can be estimated by the morphology of microcalcifications found on mammography. We correlated microcalcifications and histopathology in a retrospective blinded review. We reviewed all patients who underwent excisional breast biopsy over a 5 1/2-year period. Mammograms and pathology slides of all patients (n = 49) with DCIS of the breast were included in a blinded retrospective analysis. Mammographic microcalcifications were divided into four categories, "linear branching", "coarse granular", "fine granular" or "no microcalcification". Independently, pathology specimens were assigned to poorly, intermediately and well differentiated categories according to the consensus classification of DCIS introduced by the European Organisation for the Research and Treatment of Cancer. Two patients had no microcalcifications. 25 (53%) of the remaining 47 patients had "linear branching" microcalcifications, 10 (21%) had "coarse granular" and 12 (25.5%) had "fine granular" microcalcifications. 19 patients (40%) had poorly differentiated, 23 (49%) intermediately differentiated and 5 (11%) well differentiated subtypes of DCIS. 14 (56%) of the 25 patients with "linear branching" microcalcifications had poorly differentiated DCIS, 10 (40%) had intermediately differentiated and 1 (4%) had well differentiated DCIS. 3 (30%) of 10 patients with "coarse granular" microcalcifications had poorly differentiated DCIS, 5 (50%) had intermediately differentiated and 2 (20%) had well differentiated DCIS. 2 (17%) of 12 patients with "fine granular" microcalcifications had poorly differentiated DCIS, 8 (67%) had intermediately differentiated and 2 (17%) had well differentiated DCIS. These findings were not statistically significant. In conclusion, "linear branching" microcalcifications tended to be associated with higher pathological grading. However, correlation was poor and there was considerable overlap between categories. Histological type of DCIS cannot be predicted prospectively on mammographic appearances.

Adult↗
PubMed1999

Spiral CT angiography of renal arteries: comparison with angiography.

A prospective study was carried out to determine the accuracy of spiral CT angiography (CTA) in the detection of renal artery stenosis (RAS). Eighty-two patients with arterial hypertension underwent CTA and digital subtraction angiography (DSA) to exclude RAS. For CTA a contrast medium bolus of 100-150 ml (flow rate 3 ml/s) was injected. A 24 or 40 s CTA was started at the origin of the superior mesenteric artery after a delay time determined by test bolus injection (collimation = 2 mm, pitch = 1/1.5). For stenosis detection transverse images supported by maximum intensity projections (MIP) or multiplanar reconstruction projections were used. Of 197 renal arteries examined (including 33 accessory arteries), 34 RAS were visualized using DSA. With CTA, one hemodynamic RAS was missed and one additional hemodynamic RAS was found. Sensitivity/specificity was calculated to be 94 %/98 %. For hemodynamically relevant RAS (> 50 %) the sensitivity/specificity was 96 %/99 %. CTA additionally depicted five adrenal masses. The high accuracy rate of RAS detection thus allows the use of CTA as a screening method in patients with arterial hypertension to exclude a renovascular cause.

Adult↗
PubMed1999

Multivariate analysis of the adjustment of the colour duplex unit for the differential diagnosis of lymph node alterations.

Intranodal angioarchitecture was used as criterion for the differential diagnosis of lymph node alterations by colour duplex sonography. The influence of the adjustment of the duplex unit on the diagnostic accuracy and on the rate of lymph nodes with detectable intranodal flow signals was tested. A total of 243 superficial lymph nodes in 127 patients were included in a retrospective study. Diagnoses were approved by histopathology (n = 173) or clinical follow-ups (n = 70 reactive lymph nodes). The intranodal angioarchitecture and sonomorphology were assessed. We used nonparametric discriminant analysis in order to define appropriate settings for transducer frequency, flow mode, power and threshold which result in the best diagnostic quality. Of the lymph nodes, 87 % displayed flow signals using a threshold of >/= 13 and the flow modes low or medium. Vascularisation was detected only in 47 % of the nodes assessed with different adjustments. Diagnostic accuracy dropped from 94 to 68-84 % if threshold was < 13 or power was less than -11 dB. An insufficient adjustment of the colour duplex unit decreases the chance of detecting intranodal flow signals and impairs the diagnostic quality of colour duplex sonography. Flow mode, power and threshold are the most important parameters which have to be adjusted properly.

Adolescent↗
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

Chronic recurrent osteomyelitis with clavicular involvement in children: diagnostic value of different imaging techniques and therapy with non-steroidal anti-inflammatory drugs.

UNLABELLED: Chronic recurrent, uni- or multifocal osteomyelitis (CRMO), an inflammatory disorder of unknown origin, involves mk:/night/arul/4310946m.3dultiple osseous sites and may affect the clavicle. We report on 6 children with clavicular involvement out of 11 children suffering from CRMO. The major clinical symptoms were local swelling and pain. Five children had hyperostosis of the clavicle and synovitis of adjacent joints. Histology showed chronic osteomyelitis with a predominance of lymphocytes in the inflammatory infiltrates. Cultures of biopsy tissue specimens were sterile. The patients were followed for at least 3.5 years. Three patients had up to six relapses. The most effective diagnostic tools to define CRMO were standard X-ray and bone scan in combination with biopsy and cultures. In our patients CT and MRI were misleading as they suggested the presence of malignancy. However, the sensitivity of MRI to detect involvement of bone, adjacent joints and soft tissues were better in comparison to X-ray or bone scan. Non-steroidal anti-inflammatory drugs were effective in reducing pain, swelling and limitation of motion. Reconstructive surgery was not indicated in any case. The long-term outcome of growth and function of affected bones was excellent. CONCLUSION: Diagnosis of chronic osteomyelitis of the clavicle should be made by history and physical examination and be confirmed by standard X-ray, bone scan and open biopsy. In contrast MRI and CT can provide data on the involvement of adjacent joints, soft tissue and muscles especially in the early process of disease, but do not add information relevant to the patient's management. Treatment with non-steroidal anti-inflammatory drugs is rapidly beneficial in most patients.

Adolescent↗
PubMed1998

[Value of color-coded duplex ultrasound in evaluating arm blood vessels--arteries and hemodialysis shunts].

AIM: Comparison of colour coded duplex sonography (CCDS) to angiography in visualizing arteries and haemodialysis fistulas of the upper extremity. METHOD: 1145 arterial and vein segments were visualised using CCDS and angiography in 219 patients by different examiners with different degrees of experience. Sensitivity, specificity and accuracy were calculated. RESULTS: For the arterial segments--subclavian artery up to the distal lower arm arteries--the sensitivity was 90% and the specificity 99%. The sensitivity for the detection of vascular alterations in haemodialysis fistulas was 89% and the specificity 95%. CONCLUSION: CCDS may be able to replace diagnostic angiography of the arm except when evaluating the hand arteries and the central veins.

Adult↗