[Unusual subcutaneous metastasis of malignant melanoma].
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Antineoplastic Combined Chemotherapy Protocols↗
Biomedical subjects
S Feuerbach
Publications and source records attributed to S Feuerbach.
[Radiologic implantation of central venous portal systems in the forearm].
PURPOSE: To assess the safety and effectiveness of fluoroscopic guided brachial implanted central-venous miniport systems. PATIENTS AND METHODS: In 32 oncological patients a central-venous miniport system (Vital-Port, CPC-Cook) was implanted in the forearm. The group included 15 women and 17 men (range 33-78, mean 56 years). RESULTS: Technical success was 100%, in 6 patients vasospasm produced difficulties in catheter placement. In a total of 2878 patients days (range 3-445, mean 90 days) 5 complications occurred (15.6%, 1.7 on 1,000 catheterdays): In one patient (3.13%, 0.35/ 1000 d) the system was changed due to leakage of the catheter near the chamber. Four patients had minor complications: in one case excision of a suture line granuloma was necessary, one haematoma at the site of the chamber was treated with dressing, one patient had a wound dehiscence and one occluded catheter returned to patency by flushing the system with contrast material. Venous thrombosis, phlebitis, catheter dislocation, paravasation or system-related infection did not occur. CONCLUSION: Fluoroscopic guided peripheral central-venous port implantation is a safe and easy procedure with a high success rate and a low complication rate which can be performed in an outpatient setting.
Adult↗
[Percutaneous abscess drainage in Crohn disease].
PURPOSE: To evaluate the success of percutaneous, CT-guided abscess drainage (PAD) in patients with Crohn's disease. METHODS: Within the last 5 years 8 patients with Crohn's disease were treated by PAD for intra-abdominal abscesses. A fistula was determined to be the cause in 4 patients. The abscesses arose spontaneously in 7 patients while one patient had a postoperative abscess. We used single lumen 10 F- and double lumen 12 F- and 14 F-catheters for drainage (duration of drainage 8-20 days). RESULTS: In all cases the abscess was successfully drained by PAD. However, an operation-free interval of at least three months was achieved in only two patients. A healing of the fistula was not attained in any of the 4 patients with a proven fistula. No enterocutaneous fistulas arose within the course of PAD. CONCLUSIONS: PAD is also useful for patients with Crohn's disease since it improves the starting situation for the necessary operative interventions. In most cases (especially with enterogenic fistulas), however, a long-lasting therapeutic result cannot be expected.
Abdominal Abscess↗
Dedicated head-neck coil in MR angiography of the supra-aortic arteries from the aortic arch to the circle of Willis.
PURPOSE: To evaluate the usefulness of a dedicated head-neck coil in preoperative imaging of the supra-aortic arteries. MATERIAL AND METHODS: Forty consecutive patients with suspected carotid artery stenosis underwent MR angiography (MRA). Using a dedicated head-neck coil, we made a complete evaluation of the supra-aortic arteries and graded the internal carotid artery (ICA) stenoses. MRA was performed at 1.5 T with: coronal 3D FISP from the aortic arch to the circle of Willis; transverse 2D FLASH and 3D TONE of the carotid bifurcation; transverse 3D TONE of the carotid siphon and the circle of Willis; and transverse 3D FISP of the aortic arch. I.a. digital subtraction angiography (DSA) was used as the reference. ICA stenoses of 70% and more at DSA (NASCET methodology) were regarded as severe. RESULTS: Severe ICA stenoses were detected with high sensitivity and specificity: 93% and 92% respectively for coronal 3D FISP; 90% and 85% respectively for transverse 2D FLASH; and 97% and 94% respectively for transverse 3D TONE. The carotid siphon and the intracranial ICA were best depicted by 3D TONE. None of the applied sequences gave a satisfactory visualization of the aortic arch or of the origins of the vertebral arteries. CONCLUSION: With the head-neck coil, the supra-aortic arteries (including the intracranial vessels) were visualized without the need to reposition the patient, but depiction of the aortic arch was not acceptable. The quantification of ICA stenoses was reliable.
Aged↗
Air oesophagogram: a frequent, but not a specific sign of oesophageal involvement in connective tissue diseases.
OBJECTIVE: This study investigates the role of the air oesophagogram in conventional chest X-rays for the diagnosis of oesophageal dysmotility in patients with connective tissue diseases. METHODS: Fifty-one patients with connective tissue diseases were studied by oesophageal manometry and lateral and posterior-anterior chest X-rays. The presence or absence of oesophageal air on chest X-rays were evaluated separately in the upper, middle and distal segment of the oesophagus. Forty-seven chest X-rays of patients without connective tissue diseases, who had undergone manometry for the evaluation of oesophagus-related symptoms and who had normal oesophageal function, were analysed as a control. RESULTS: A total of 23/51 patients with connective tissue diseases showed oesophageal dysfunction in manometry; 16/51 patients (31%) had air in two or more oesophageal segments on the lateral chest X-ray. There was a significant association of manometrically proven oesophageal dysmotility and air in two or three oesophageal segments (P < 0.05; sensitivity 48%, specificity 82%). However, the prevalence of an air oesophagogram showed no significant difference between patients with connective tissue diseases and the control group (10/47; 21%). CONCLUSION: The radiological sign of an air oesophagogram is neither sensitive nor specific enough to omit oesophageal motility studies in patients with connective tissue diseases.
Air↗
Amorphous silicon, flat-panel, x-ray detector versus screen-film radiography: effect of dose reduction on the detectability of cortical bone defects and fractures.
RATIONALE AND OBJECTIVES: The purpose of this phantom study was to assess the diagnostic performance of a self-scanning, solid-state amorphous silicon (a-Si) detector in skeletal radiography using different exposure parameters. METHODS: A flat-panel detector (15 cm x 15 cm), based on a-Si technology with 143 microm x 143 microm pixel size, 1k x 1k matrix, and 12 bit digital output was used. State-of-the-art screen-film radiography (SFR; speed 400, detector dose 2.5 microGy) was compared with a-Si images taken at doses that were equivalent to a speed of 400, 800, 1,250, and 1,600, respectively. A total of 232 segments of long tubular deer-bones (femur, tibia, humerus, radius) had 110 artificial fractures and 112 cortical defects simulating osteolytic lesions. Receiver operating characteristic analysis was performed for 9,280 observations made by four independent observers. Two-tailed Student's paired t test was used for statistical analysis (95% confidence level). RESULTS: Receiver operating characteristic analysis yielded equivalent results of the a-Si and SFR system. Even at the lowest dose there were no statistically significant differences between both imaging modalities with respect to the detectability of fractures and cortical defects. CONCLUSIONS: The results of this study indicate that a-Si detector technology holds promise in terms of dose reduction in skeletal radiography without loss of diagnostic accuracy.
Animals↗
Detection of simulated chest lesions with normal and reduced radiation dose: comparison of conventional screen-film radiography and a flat-panel x-ray detector based on amorphous silicon.
RATIONALE AND OBJECTIVES: The authors compared a solid-state amorphous silicon (a-Si) detector and screen-film radiography (SFR) with regard to the detection of simulated pulmonary lesions. Evaluation of the impact of a dose reduction of 50% with this digital flat-panel detector was of special interest. METHODS: A self-scanning flat-panel detector, based on a-Si technology with 143 x 143 microm pixel size, 1 k x 1 k matrix and 12-bit digital output was used. An asymmetric state-of-the-art screen-film system was compared with a-Si images taken at the same dose as SFR-images and at a dose reduced by 50%. An anthropomorphic chest phantom was superimposed by templates containing nodules, linear structures, reticular, and micronodular opacities in a random distribution. Receiver operating characteristic analysis was performed for 23,040 observations made by four independent observers. Student's t test (95% confidence-level) was used for statistical analysis. RESULTS: Receiver operating characteristic analysis showed that a-Si images taken at the same dose as SFR-images were significantly superior to SFR with respect to the detectability of lines (P = 0.01) and micronodular opacities (P < 0.01). For the other objects and the a-Si images taken at a reduced dose, it yielded no statistically significant differences between both imaging modalities. CONCLUSIONS: The results of this phantom study indicate that a-Si detector technology holds promise in terms of dose reduction in chest radiography without loss of diagnostic accuracy compared with SFR.
Humans↗
Clinical application of a flat-panel X-ray detector based on amorphous silicon technology: image quality and potential for radiation dose reduction in skeletal radiography.
OBJECTIVE: The purpose of this study was to compare images obtained with a self-scanning, flat-panel X-ray detector based on amorphous silicon technology with conventional screen-film radiographs and to evaluate the possibility of radiation dose reduction in skeletal radiography. SUBJECTS AND METHODS: One hundred twenty patients were examined prospectively using a conventional screen-film system (speed, 400; detector dose, 2.5 microGy) and a prototype digital amorphous silicon detector (simulated speed, 400 and 800, n = 120; simulated speed, 1600, n = 40). The resulting 400 images were evaluated independently by six radiologists using a subjective five-point preference scale that rated overexposure, underexposure, contrast resolution, spatial resolution, and soft-tissue presentation. Image quality was ranked on a scale from 0 to 10 according to subjective criteria. Statistical significance of differences was determined using Student's t test and confidence intervals (95% confidence level). RESULTS: Comparison of conventional radiographs with digital images revealed a statistically significant preference for the digital system for soft-tissue presentation (speed 400 and 800) and visualization of osteoarthrotic changes (speed 400). A small but statistically significant preference for conventional images was found with respect to contrast and spatial resolution when digital speed was 800 or 1600; and the visibility of arthrosis at digital speed 1600, osteolysis at digital speed 800 and 1600, and fractures at digital speed 1600. CONCLUSION: The amorphous silicon-based system with a simulated speed of 400 provided images equivalent to screen-film radiographs. For clinical tasks such as routine follow-up studies, assessment of instability, or orthopedic measurements, a radiation dose reduction of up to 75% may be possible.
Aged↗
[Computer tomography-guided gastrostomy, jejunostomy and gastrojejunostomy. A reliable non-surgical method also for contraindications and failure of percutaneous endoscopic gastrostomy].
OBJECTIVE: To analyse retrospectively the results of CT (computed tomography)-guided gastrostomy or gastroenterostomy where an endoscopic procedure was not possible or had failed. PATIENTS AND METHODS: Between August 1993 and March 1997, CT-guided gastrostomy (n = 50) or gastroenterostomy (n = 8) was performed in 58 patients (mean age 56 +/- 6 years; 51 males, 7 females). An endoscopic or fluoroscopic method had been contraindicated in 52 and had failed in 6 patients. RESULTS: Technical success was achieved in all patients. Three patients needed intravenous sedation. There were no procedure related complications requiring treatment. Three patients had a mild infection at the site of the skin puncture. CONCLUSION: CT-guided gastrostomy or gastroenterostomy is a safe and simple procedure which provides a minimally invasive alternative also in patients with contraindications to the established percutaneous method.
Adult↗
Magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) of intracranial lipomas.
We show a detailed magnetic resonance (MR) examination of two rare pericallosa lipomas with a fat suppression imaging sequence and proton MR spectroscopy. For comparison, subcutaneous fat and lipids in glioblastomas were examined with H MR spectroscopy in vivo and ex vivo. Fat suppression makes the identification of lipomas simple. It is suggested that H MR spectroscopy shows no differences in the aliphatic chain length of lipoma and subcutaneous fat, whereas lipids in glioblastomas have a much shorter chain length. Chain length of fatty acids in lipoma measured with in vivo MR spectroscopy are in concordance with data from the literature.
Adipose Tissue↗
[Radiologic diagnosis of space-occupying lesions of the liver. Computerized tomography, magnetic resonance tomography, angiography].
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Angiography↗
Cerebral abnormalities in patients with cirrhosis detected by proton magnetic resonance spectroscopy and magnetic resonance imaging.
Hepatic encephalopathy is a common problem in cirrhosis. The pathogenesis of this complication of advanced liver disease still remains unclear. Magnetic resonance spectroscopy was used to assess prospectively cerebral metabolism in 51 patients with histologically proven cirrhosis (Child-Pugh classes A, B, and C, 18, 18, and 15, respectively) and 36 healthy volunteers. According to the results of psychometric tests, overt hepatic encephalopathy, subclinical encephalopathy, and no encephalopathy were found in 14, 21, and 16 patients, respectively. Myoinositol/creatine ratios in gray (.36 +/- .17) and white (.35 +/- .22) matter voxel were reduced significantly (P < .0001) in cirrhotic patients compared with healthy volunteers (gray matter, .51 +/- .11; white matter, .64 +/- .16). In addition, patients showed a significant reduction (P = .024) in white matter choline/creatine ratio (.77 +/- .27) compared with controls (.92 +/- .25), and glutamine/glutamate level was elevated in cirrhotic patients compared with controls (gray matter, P < .0001; white matter, P = .036). Changes in cerebral myoinositol and glutamine/glutamate levels correlated significantly with the severity of hepatic encephalopathy (P < .0001). However, these metabolic alterations were also detected in patients without hepatic encephalopathy (normal psychometric test results). N-acetyl aspartate/creatine ratios did not differ between patients and controls. Magnetic resonance imaging detected bright basal ganglia in 37 patients, which correlated significantly with portal-systemic shunting and elevation of glutamine/glutamate, but not with the degree of hepatic encephalopathy. In conclusion, magnetic resonance imaging and spectroscopy showed that alterations of cerebral metabolism are common in patients with cirrhosis, even without evidence of clinical or subclinical hepatic encephalopathy.
Adult↗
[Artifacts in MR imaging of the temporomandibular joint caused by dental alloys: a phantom model study at T1.5].
PURPOSE: The influence of dental alloys on MRI of the temporomandibular joint was studied using a phantom model for this joint. METHODS: At 1,5 T, 15 dental alloys and 14 of their most important components were investigated acquiring sagittal (FOV: 150 mm) and transverse (FOV: 250 mm) T1-weighted SE images. In 11 cases, T1- and T2*-weighted FLASH images were measured additionally. The artifacts were assessed qualitatively as well as quantitatively, and the samples were subdivided into four artifact categories. RESULTS: Ag, Cu, Ga, In, Tl, Sn, Zn, amalgam, the precious alloys, the Au-Pd and Ag-Pd alloys showed no artifacts (category I). Minimal artifacts below 10 mm on transverse images (category II) were found for Cr, Pd, Pt and for the Ni-Cr alloy. Mn and the remaining non-precious alloys induced artifacts up to 30 mm (category III). Significant artifacts-more than 30 mm-(category IV) were caused by Ni-Cr and 18/8 wires and by Co, Fe, and Ni. T2*-weighted FLASH proved to be more susceptible for artifacts than T1-weighted SE and FLASH techniques. CONCLUSIONS: In contrast to dental alloys for fixed prosthodontics, Ni-Cr- or 18/8 wires used for orthodontic bands can influence not only the image quality, but also the diagnostic reliability of MRI of the temporomandibular joint.
Artifacts↗
Diagnosis of liver metastases from colorectal adenocarcinoma. Comparison of spiral-CTAP combined with intravenous contrast-enhanced spiral-CT and SPIO-enhanced MR combined with plain MR imaging.
PURPOSE: The purpose of this study was to determine whether MR with and without SPIO (AMI-25) could replace spiral-CTAP in the staging of colorectal adenocarcinoma. MATERIAL AND METHODS: Thirty-five patients were studied prospectively by means of i.v. contrast-enhanced spiral-CT, spiral-CTAP, and MR of the liver. MR imaging was performed before and after infusion of AMI-25. Diagnoses were compared to intraoperative findings (n = 35) which included intraoperative ultrasound (n = 21), and follow-up CT (n = 18). RESULTS AND CONCLUSION: Fifteen patients were found to have a total number of 53 liver metastases and 43 benign lesions were detected. Evaluation was performed in four different ways: 1) i.v. contrast-enhanced spiral-CT; 2) i.v. contrast-enhanced spiral-CT + spiral-CTAP; 3) plain MR; 4) plain MR + SPIO-enhanced MR. I.v. contrast-enhanced spiral-CT, spiral-CTAP and SPIO-enhanced MR identified patients with liver metastases with equal sensitivity. However, owing to its significantly higher sensitivity, based on a lesion-by-lesion analysis, spiral-CTAP cannot be replaced by SPIO-enhanced MR in patients who are to undergo liver resection. A limitation in spiral-CTAP is its relatively low specificity.
Adenocarcinoma↗
Cerebral CT angiography in the diagnosis of acute subarachnoid hemorrhage.
PURPOSE: To evaluate the usefulness of CT angiography (CTA) in the detection of intracranial aneurysms in patients with acute subarachnoid hemorrhage (SAH). MATERIAL AND METHODS: In 53 patients with nontraumatic SAH a helical contrast-enhanced CTA was performed. CTA data were reconstructed with maximum intensity projection (MIP). Each patient underwent selective arteriography of the cerebral vessels (as the gold standard). CTA (axial images and MIP reconstructions) and arteriography were evaluated separately and their diagnostic information was compared. RESULTS: In 14 of the 53 patients neither CTA nor angiography showed a vascular malformation. In the remaining 39 patients, angiography demonstrated a total of 51 aneurysms ranging in size from 3 mm to 16 mm. CTA missed one of these aneurysms, which was located at the internal carotid artery. 3-D CT reconstruction was slightly superior to arteriography in the demonstration of the neck, shape and direction of the aneurysms. Partial thrombosis of 3 aneurysms was demonstrated only by CTA. CONCLUSION: Although CTA cannot replace cerebral arteriography in the diagnostic work-up of acute SAH, it proved to be helpful in demonstrating the topographic anatomy of cerebral aneurysms and surrounding structures.
Acute Disease↗
Flat-panel x-ray detector using amorphous silicon technology. Reduced radiation dose for the detection of foreign bodies.
RATIONALE AND OBJECTIVES: The authors evaluate a new flat-panel x-ray detector (FD) with respect to foreign body detection and reduction of radiation dose compared with screen-film radiography. METHODS: Flat-panel x-ray detector is based on amorphous silicon technology and uses a 1 k x 1 k photo-detector matrix with a pixel size of 143 x 143 microns and 12-bit digital output. A thallium-dotted cesium iodide scintillation layer converts x-rays into light. An ex vivo experimental model was used to determine the detectability of foreign bodies. Foreign bodies with varying sizes were examined: glass with and without addition of lead, bone, aluminium, iron, copper, gravel fragments, and graphite. Four hundred observation fields were examined using conventional radiography (speed, 400; system dose: 2.5 microGy) as well as FD with a simulated speed of 400, 800, 1200, and 1600, corresponding to a detector dose of 2.5 microGy, 1.25 microGy, 0.87 microGy, and 0.625 microGy, respectively. Four independent radiologists performed receiver operating characteristic analysis of 8000 observations. RESULTS: Flat-panel x-ray detector with a simulated speed of 400 was significantly superior (P = 0.012) to screen-film radiography (speed, 400). At a simulated speed of 800 and 1200 FD yielded results equivalent to screen-film radiography. Flat-panel x-ray detector was significantly inferior to screen-film radiography at a simulated speed of 1600 (P = 0.012). CONCLUSIONS: Flat-panel x-ray detector technology allows significant reduction in radiation dose compared with screen-film radiography without loss of diagnostic accuracy.
Foreign Bodies↗
[CT-guided percutaneous endoscopic gastrostomy: a successful method if transillumination is not possible].
BACKGROUND AND OBJECTIVE: If transillumination is not possible, percutaneous endoscopic gastrostomy (PEG) is contraindicated. In these cases the stomach had so far to be punctured directly during radiological monitoring. A new method is described which combines endoscopy and computed tomography (CT) for performing a percutaneous endoscopic gastrostomy. PATIENTS AND METHODS: Among 189 patients who were to have the procedure there were eleven (nine men, two women) in whom transillumination was not possible. After endoscopic insufflation of air PEG was done under CT guidance, using the common pull-through technique. RESULTS: The combined method was successful in ten of the eleven patients without complication. In one patient with hepatomegaly and interposition of the transverse colon PEG was not possible even with CT guidance. CONCLUSIONS: The combined endoscopic-radiological method is practicable and safe in cases in which transillumination is not possible. There are several advantages compared with direct puncturing: The common pull-through technique can be used; radiological exposure is low and other clinically relevant findings may be revealed by the endoscopy.
Adult↗
CT-guided PEG in patients with unsuccessful endoscopic transillumination.
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Adult↗