PubMed Health⌕ Search

Biomedical subjects

Stefan Feuerbach

Publications and source records attributed to Stefan Feuerbach.

At least 19 recordsLinked to original sources
PubMed2006

Indirect MR arthrography of the shoulder: use of abduction and external rotation to detect full- and partial-thickness tears of the supraspinatus tendon.

PURPOSE: To evaluate prospectively the accuracy of indirect magnetic resonance (MR) arthrography for supraspinatus tendon tears during neutral positioning or abduction and external rotation (ABER) and neutral positioning. MATERIALS AND METHODS: Informed consent was obtained in all patients, and the study was approved by the institutional review board. Indirect MR arthrography of the shoulder was performed in 51 symptomatic patients (14 female, 37 male; mean age, 47 years) in the neutral position (set 1) and in the neutral and ABER positions (set 2). Two readers independently interpreted both sets, and diagnoses were compared with arthroscopic findings. Diagnostic accuracy was calculated, and 95% confidence intervals were used to detect significant differences between sets. Diagnostic confidence was recorded by using a three-level confidence score. Differences between sets were evaluated by using the Wilcoxon signed rank test. Interobserver agreement was determined separately for each set and for all diagnoses, full-thickness tears, and partial-thickness tears. RESULTS: For full-thickness tears, there was no benefit to reading set 2. For reader 1, sensitivity and specificity were 95% and 100%, respectively, for set 1 and 100% and 100%, respectively, for set 2. For reader 2, sensitivity and specificity were 80% and 100%, respectively, for set 1 and 100% and 100%, respectively, for set 2. For partial-thickness tears, sensitivity was significantly higher after reading set 2. For reader 1, sensitivity and specificity were 71% and 88%, respectively, for set 1 and 93% and 100%, respectively, for set 2. For reader 2, sensitivity and specificity were 50% and 88%, respectively, for set 1 and 86% and 94%, respectively, for set 2. For both readers, diagnostic confidence for partial-thickness tears was significantly higher after reading set 2. After the interpretation of set 2, kappa values increased from 0.35 to 1.00 for full-thickness tears and from 0.12 to 0.63 for partial-thickness tears. CONCLUSION: Indirect MR arthrography with supplementary images obtained with patients in the ABER position significantly improved sensitivity and increased diagnostic confidence for partial-thickness tears of the supraspinatus tendon. Interobserver agreement was improved for both full- and partial-thickness tears.

Adolescent↗
PubMed2006

[Analysis of MR image quality of echo planar diffusion-weighted imaging: investigations at 1.5 Tesla with higher gradient field strength].

PURPOSE: Single-shot echo planar Diffusion-weighted-Imaging (EPI DWI) requires extended gradient facilities with strong, fast switching gradients. Up to now the image quality of EPI DWI is enormously influenced by some kinds of artifacts. Therefore we evaluated the image quality of EPI DWI in demonstrating anatomical structures using a 1.5 T MR scanner with a higher gradient field strength of 40 mt/m, a risetime of 200 micros and a slewrate of 200T/m/s. MATERIALS AND METHODS: Using an evaluation scale with four categories two independent readers evaluated 12 different infra- and supratentorial anatomic regions of the brain on 50 DWI images and compared them with the corresponding T2 turbospin echo image. RESULTS: No region was judged to be undistinguishable. On axial DWI images the assessment of the brain stem was poor. In the level of the putamen and thalamus the image quality of DWI was judged to be from adequate to excellent. The central sulcus and the boundary of the white and grey matter was assessed to be adequately visible. The interobserver variability showed a good agreement between the two readers. CONCLUSION: The image quality of EPI DWI improves from a higher gradient field strength. The shortening rise time of 200 micros and the slewrate of 200 T/m/s will lead to a faster gradient switching. Single shot EPI DWI is less influenced by image artefacts and the presentation of different anatomical structures profits when a MR scanner with higher gradient field strength is used.

Adolescent↗
PubMed2005

Chest radiography with a flat-panel detector: image quality with dose reduction after copper filtration.

PURPOSE: To compare image quality and estimated dose for chest radiographs obtained by using a cesium iodide-amorphous silicon flat-panel detector at fixed tube voltage and detector entrance dose with and without additional 0.3-mm copper filtration. MATERIALS AND METHODS: The study was approved by the institutional ethics committee. All prospectively enrolled patients signed the written consent form. Chest radiographs in two projections were acquired at 125-kVp tube voltage and 2.5-microGy detector entrance dose. The experimental group (38 patients) was imaged with 0.3-mm copper filtration; the control group (38 patients) was imaged without copper filtration. An additional 12 patients were imaged with and without copper filtration and served as paired subject-controls. Three readers blinded to group and clinical data independently evaluated the radiographs for image quality on a digital display system. Twelve variables (six for each radiographic projection) were assigned scores on a seven-point ordinal scale. Scores between experimental and control groups were compared: Logistic regression analysis and Mann-Whitney U test were used for unpaired patients; and Wilcoxon and McNemar test, for paired patients. In all, 72 comparisons were determined (36 [12 variables x three readers] for unpaired patients and 36 for paired patients). In a phantom study, radiation burden of experimental protocol was compared with that of control protocol by using Monte Carlo calculations. RESULTS: For 70 of 72 comparisons, digital radiographs obtained with copper filtration were of similar image quality as radiographs obtained without copper filtration (P = .123 to P > .99). For two of 72 comparisons, one observer judged the experimental protocol superior to the control protocol (P = .043, P = .046). Patient dose reduction estimated with Monte Carlo calculations was 31%. Use of copper filtration increased exposure times by 48% for posteroanterior views and by 34% for lateral views. CONCLUSION: Subjectively equivalent chest radiographic image quality was found with estimated 30% dose reduction after addition of 0.3-mm copper filtration with flat-panel cesium iodide-amorphous silicon technology.

Cesium↗
PubMed2005

Planimetry of mitral valve stenosis by magnetic resonance imaging.

OBJECTIVES: We sought to determine whether noninvasive planimetry of the mitral valve area (MVA) by magnetic resonance imaging (MRI) is feasible and reliable in patients with mitral stenosis (MS). BACKGROUND: Accurate assessment of MVA is particularly important for the management of patients with valvular stenosis. Current standard techniques for assessing the severity of MS include echocardiography (ECHO) and cardiac catheterization (CATH). METHODS: In 22 patients with suspected or known MS, planimetry of MVA was performed with a 1.5-T magnetic resonance scanner using a breath-hold balanced gradient echo sequence (true FISP). Data were compared with echocardiographically determined MVA (ECHO-MVA, n = 22), as well as with invasively calculated MVA by the Gorlin-formula at (CATH-MVA, n = 17). RESULTS: The correlation between MRI- and CATH-MVA was 0.89 (p < 0.0001), and the correlation between MRI- and ECHO-MVA was 0.81 (p < 0.0001). The MRI-MVA slightly overestimated CATH-MVA by 5.0% (1.60 +/- 0.45 cm(2) vs. 1.52 +/- 0.49 cm(2), p = NS) and ECHO-MVA by 8.1% (1.61 +/- 0.42 cm(2) vs. 1.48 +/- 0.42 cm(2), p < 0.05). On receiver-operating characteristic curve analysis, a value of MRI-MVA below 1.65 cm(2) indicated mitral stenosis (CATH-MVA < or =1.5 cm(2)), with a good sensitivity and specificity (89% and 75%, respectively). CONCLUSIONS: Magnetic resonance planimetry of the mitral valve orifice in mitral stenosis offers a reliable and safe method for noninvasive quantification of mitral stenosis. In the clinical management of patients with mitral stenosis, it has to be considered that planimetry by MRI slightly overestimates MVA, as compared with MVA calculated echocardiographically and at catheterization.

Aged↗
PubMed2005

Comparison of capsule endoscopy and magnetic resonance (MR) enteroclysis in suspected small bowel disease.

BACKGROUND AND AIMS: Small bowel MR enteroclysis and wireless capsule endoscopy (WCE) are new diagnostic tools for the investigation of the small bowel. The aim of this study was to compare the diagnostic yield of WCE with MR enteroclysis in the detection of small bowel pathologies. METHODS: A total of 36 patients were included in the study. Indications for imaging of the small bowel were proven or suspected small bowel Crohn's disease (CD; n=18), obscure gastrointestinal (GI) bleeding (n=14) and tumour surveillance (n=4). RESULTS: In patients with Crohn's disease WCE detected significantly more inflammatory lesions in the first two segments of the small bowel compared with MR enteroclysis (12 patients vs. 1 patient, p=0.016). In 5 out of 14 (36%) patients with GI bleeding, angiodysplasia was detected as a possible bleeding source. Three of these patients had active bleeding sites detected by WCE. One patient had scattered inflammation of the mucosa. MR enteroclysis did not reveal any intestinal abnormalities in this patient group. MR enteroclysis provided extraintestinal pathologies in 10 out of 36 (28%) patients. CONCLUSION: In patients with Crohn's disease WCE revealed significantly more inflammatory lesions in the proximal and middle part of the small bowel in comparison to MR enteroclysis, whereas in patients with obscure GI bleeding WCE was superior to MR enteroclysis.

Adolescent↗
PubMed2005

Magnetic resonance imaging, computed tomography, and conventional X-ray in 3 cases of symmelia.

BACKGROUND: Symmelia is a rare birth defect, often combined with severe malformations of the urogenital system and the lower gastrointestinal tract. Additionally, a deformed pelvis and various degrees of separation of the lower limbs are present. CASES: We report the examination findings of 3 autopsy specimens of symmelia using magnetic resonance imaging (MRI) and computed tomography (CT) with 3-dimensional (3D) reconstructions, and conventional X-ray. CONCLUSIONS: MRI and CT with the addition of 3D visualization can be used additionally with autopsy and conventional X-ray images in the investigation of such complex anatomical abnormalities.

Ectromelia↗
PubMed2005

Percutaneous treatment of a patient with infected necrotizing pancreatitis.

BACKGROUND: A 50-year-old man with an acute episode of alcohol-induced chronic edematous pancreatitis and an inflammatory stenosis of the biliary tract was treated by implantation of a plastic endoprosthesis at a rural hospital in Germany. Because of his worsening condition, the patient was referred to the intensive care unit of the University Hospital, Regensburg, Germany. Contrast-enhanced CT revealed complete necrosis of the body and tail of the pancreas, formation of large retrogastric and paraduodenal fluid collections, and fluid along Gerota's fascia, as well as in the paracolic gutters. Antibiotic treatment was adjusted according to the results of microbiological testing after diagnostic puncture of the necrotic cavity. INVESTIGATIONS: CT scan, CT-guided fine-needle aspiration and fluoroscopy. DIAGNOSIS: Infected acute necrotizing pancreatitis. MANAGEMENT: Interventional treatment using large-bore percutaneous catheters to perform percutaneous necrosectomy, fragmentation of necrotic pancreatic tissue with a snare catheter and dormia basket, and aspiration. Parenteral nutrition and antibiotics were also administered.

Bacterial Infections↗
PubMed2005

Magnetic resonance imaging gastrography: evaluation of the dark lumen technique compared with conventional gastroscopy in patients with malignant gastric disease.

OBJECTIVES: We sought to demonstrate the feasibility of depicting gastric tumors using magnetic resonance imaging (MRI) while applying the dark lumen technique. The findings were correlated with conventional gastroscopy. In addition, we evaluated the screening for lymph nodes and liver metastases during the same session to identify potential tumor spread. MATERIALS AND METHODS: The study included 15 patients with known malignant gastric disease. Conventional gastrointestinal endoscopy was performed in all patients as gold standard. All patients were examined with computed tomography for tumor staging. MRI was performed using 1 L of tap water as oral contrast agent for all protocols. The MRI program included an axial T1-weighted (T1w; 2D-FLASH) sequence, an axial STIR and T2w (TSE) sequence, and 2 postcontrast T1w (3D coronal /2D axial FLASH) sequences using 0.2 mmol/kg gadolinium diethylenetriaminepenta-acetic acid as intravenously injected contrast agent. Qualitative analysis and comparison with conventional gastroscopy were performed. RESULTS: The images obtained with the postcontrast 3D coronal T1w-FLASH sequence were the most suitable in identifying gastric tumors. Complete correlation with conventional gastroscopy was achieved in 80% of the cases and partial correlation in 13% of the cases. The same imaging sequence was also appropriate for the evaluation of lymph nodes. For the identification of liver metastases, the images obtained with the axial postcontrast T1w 2D-FLASH sequence provided a higher diagnostic confidence as compared with other imaging protocols. CONCLUSIONS: Applying the dark lumen technique through MRI is suitable for imaging gastric tumors and has the potential to become a "one-stop shopping" method because of the possibility for lymph node evaluation and screening for metastases during the same session based on the same images.

Aged↗
PubMed2005

Dark lumen magnetic resonance enteroclysis in combination with MRI colonography for whole bowel assessment in patients with Crohn's disease: first clinical experience.

BACKGROUND: Magnetic resonance enteroclysis (MRE) is a recently introduced imaging technique that assesses the small bowel with similar sensitivity and specificity as the fluoroscopically performed conventional enteroclysis. Magnetic resonance imaging colonography (MRC) seems to be a promising technique for polyp assessment in the colon. In this feasibility study, we evaluated the combination of small bowel MRI with unprepared MRC as an integrative diagnostic approach of the whole bowel in patients with Crohn's disease. METHODS: Thirty patients with known Crohn's disease were prospectively examined. No particular colonic preparation was applied. Applying the dark lumen technique in all patients, MRE and MRC were performed within 1 session using an integrative examination protocol. T2-weighted and contrast-enhanced T1-weighted sequences were acquired. Inflammation assessment (grades 0 to 2) of the colon was compared with conventional colonoscopy in 29 patient and with surgery in 1 patient. The entire colon was graded fair to good distended in all patients. In 11 of 210 evaluated colonic segments, feces hindered an adequate intraluminal bowel assessment. Twenty-three of 30 patients had complete colonoscopy as the gold standard. In 7 patients, complete colonoscopy could not be performed because of an inflamed stenosis. RESULTS: Correct grading of colonic inflammation was performed with 55.1% sensitivity and 98.2% specificity in all segments. Considering only more extensive inflammation (grade 2), the sensitivity of MRC increased to 70.2% with a specificity of 99.2%. CONCLUSIONS: The combination of MRE and MRC could improve the diagnostic value of abdominal MRI evaluation in patients with Crohn's disease. However, MRC can not replace conventional colonoscopy in subtle inflammation assessment.

Adolescent↗
PubMed2005

Magnetic resonance-guided percutaneous angioplasty of femoral and popliteal artery stenoses using real-time imaging and intra-arterial contrast-enhanced magnetic resonance angiography.

OBJECTIVE: The aim of this study was to demonstrate the possibility of performing magnetic resonance (MR)-guided interventional therapy for femoral and popliteal artery stenoses with commercially available materials supported by MR real-time imaging and intra-arterial MR angiography. MATERIALS AND METHODS: A total of 15 patients suffering from symptomatic arterial occlusive disease of the lower limbs with 19 stenoses were included. Interventional intra-arterial digital subtraction angiography was performed before and after angioplasty on each patient as standard of reference. MR images were acquired on a 1.5-T MR scanner. A fast-low-angle shot (FLASH) 3D sequence was applied for a contrast enhanced MR-angiography (ceMRA). A total of 5 mL of diluted gadodiamide was injected via the arterial access. Maximum intensity projections (MIPs) were used as roadmaps and localizers for the interactive positioning of a continuously running 2D-FLASH sequence with a temporal solution of 2 images/second. The lesion was crossed by a balloon-catheter, which was mounted on a guidewire. The visibility was provided by the radiopaque markers on the balloon and was improved by injection of 1 mL of gadolinium into the balloon. Postinterventional control was performed by intra-arterial MR angiography and catheter angiography. RESULTS: Stenoses were localized by intra-arterial MR angiography. The guidewire/balloon combination was visible, and the balloon was placed correctly to cover the entire stenoses. Balloon dilation reduced the degree of stenosis by approximately 57% on average. No complications were observed. CONCLUSION: MR-guided balloon dilation of femoral and popliteal artery stenoses supported by real-time MR imaging and intra-arterial MR angiography is feasible with commercially available materials.

Aged↗
PubMed2005

Planimetry of aortic valve area in aortic stenosis by magnetic resonance imaging.

BACKGROUND: The aim of the study was to determine whether noninvasive planimetry of aortic valve area (AVA) by magnetic resonance imaging (MRI) is feasible and reliable in patients with valvular aortic stenosis in comparison to transesophageal echocardiography (TEE) and catheterization. METHODS AND RESULTS: Planimetry of AVA by MRI (MRI-AVA) was performed on a clinical magnetic resonance system (1.5-T Sonata, Siemens Medical Solutions) in 33 patients and compared with AVA calculated invasively by the Gorlin-formula at catheterization (CATH-AVA, n = 33) as well as to AVA planimetry by multiplane TEE (TEE-AVA, n = 27). Determination of MRI-AVA was possible with an adequate image quality in 82% (27/33), whereas image quality of TEE-AVA was adequate only in 56% (15/27) of patients because of calcification artifacts (P = 0.05). The correlation between MRI-AVA and CATH-AVA was 0.80 (P < 0.0001) and the correlation of MRI-AVA and TEE-AVA was 0.86 (P < 0.0001). MRI-AVA overestimated TEE-AVA by 15% (0.98 +/- 0.31 cm2 vs. 0.85 +/- 0.3 cm2, P < 0.001) and CATH-AVA by 27% (0.94 +/- 0.29 cm2 vs. 0.74 +/- 0.24 cm2, P < 0.0001). Nevertheless, a MRI-AVA below 1,3 cm2 indicated severe aortic stenosis (CATH-AVA < 1 cm2) with a sensitivity of 96% and a specificity of 100% (ROC area 0.98). CONCLUSIONS: Planimetry of aortic valve area by MRI can be performed with better image quality as compared with TEE. In the clinical management of patients with aortic stenosis, it has to be considered that MRI slightly overestimates aortic valve area as compared with catheterization despite an excellent correlation.

Aged↗
PubMed2005

In vivo evaluation of the carotid wallstent on three-dimensional contrast material-enhanced MR angiography: influence of artifacts on the visibility of stent lumina.

PURPOSE: Contrast material-enhanced magnetic resonance (MR) angiography is increasingly used in postinterventional imaging after implantation of endovascular stents. The main limitations are stent-related artifacts compromising the visibility of the stent lumen. The aim of this in vivo study is the evaluation of contrast-enhanced MR angiography imaging characteristics of the carotid Wallstent. MATERIALS AND METHODS: The carotid arteries of 29 patients were examined with contrast-enhanced MR angiography 3-6 days and/or 7-23 months after implantation of a carotid Wallstent into the internal carotid artery. Images were evaluated with regard to the diameter and signal intensity (SI) of the visible stent lumen. Digital subtraction angiography (DSA) was used as the standard of reference. RESULTS: Stent-related artifacts on contrast-enhanced MR angiography caused an artificial lumen narrowing and a reduction of the SI within the stent. Artifacts were pronounced on imaging 3-6 days after stent implantation, but 68% of stents imaged 7-23 months after stent implantation presented with a significantly decreased artificial signal reduction and an improved visibility of the stent lumen. CONCLUSIONS: The results of this study indicate that a reliable evaluation of the stent lumen is limited as a result of an artificial decrease of the SI inside the stent. However, in follow-up examinations 7-23 months after stent implantation, visibility of the stent lumen was improved and diagnostic reliability of contrast-enhanced MR angiography was markedly increased. A probable explanation for this phenomenon might be the formation of a neointimal layer covering the stent struts and thereby reducing stent-related artifacts.

Adult↗
PubMed2005

Early treatment with pentoxifylline reduces lung injury induced by acid aspiration in rats.

STUDY OBJECTIVES: To evaluate the effect of pentoxifylline treatment on gas exchange and mortality immediately after bilateral instillation of hydrochloric acid. DESIGN: Randomized, prospective, placebo-controlled trial. SETTING: Animal laboratory of a university hospital. SUBJECTS: Twenty-four, adult, male Sprague-Dawley rats. METHODS: Sevoflurane-anesthetized rats (n = 12 in each group) underwent tracheostomy and insertion of a cannula into a hind paw vein and the left carotid artery. All animals received volume-controlled mechanical ventilation (zero positive end-expiratory pressure; fraction of inspired oxygen, 0.21). Acute lung injury was induced by instillation of 0.4 mL/kg 0.1 mol/L hydrochloric acid. The animals were randomized into two groups. The pentoxifylline group (n = 12) received a bolus of 20 mg/kg IV pentoxifylline after aspiration, followed by a continuous infusion of 6 mg/kg/h. The placebo group (n = 12) received an equivalent volume of saline solution. Arterial blood samples were collected for blood gas analysis 15 min and 0 min prior to aspiration and 30, 90, 180, 270, and 360 min after aspiration. Hemodynamic parameters, temperature, and ECG were recorded simultaneously. The primary end point was 6 h after aspiration. All surviving rats were killed by IV administration of pentobarbital. To assess morphologic changes due to lung injury, all animals underwent CT in inspiratory hold at the end of the experiment. MEASUREMENTS AND RESULTS: No difference in baseline measurements was observed. In pentoxifylline-treated rats, Pao(2) was significantly increased (p < 0.05) at 30, 90, 180, 270, and 360 min. Mortality at 6 h was 17% in the pentoxifylline group vs 67% in the placebo group. Placebo-treated rats showed significant abnormalities in CT lung scans compared with the pentoxifylline group. CONCLUSIONS: Acid aspiration impairs gas exchange and induces hypotension. Pentoxifylline administration shortly after acid instillation results in significant alleviation of impaired oxygenation, stabilization of BP with higher heart rates, and improved survival after 6 h.

Animals↗
PubMed2005

In vivo evaluation of patency and in-stent stenoses after implantation of nitinol stents in iliac arteries using MR angiography.

OBJECTIVE: Our study was a prospective in vivo study to evaluate whether MR angiography is suitable for assessing stent patency and grading in-stent stenoses and to examine whether the accuracy of MR angiography changes with time after stent implantation. SUBJECTS AND METHODS: In a prospective study, 34 iliac stenoses in 27 patients were treated by implantation of 35 nitinol stents. MR angiography was performed immediately after stent placement for 32 stents, and both digital subtraction angiography (DSA) and MR angiography were repeated at the 6-month follow-up for 23 stents. Three blinded observers assessed stent patency and the degree of in-stent stenoses on MR angiography and DSA (the standard of reference) images. The difference between the observers' grading of stenoses on DSA and on MR angiography was determined. Statistical analysis was performed using the Student's t test for paired samples. RESULTS: Stent patency was assessed correctly for all stents and both sets of MR angiography images. Evaluation of DSA 1 images (obtained at end of implantation procedure) revealed that 96.9% of in-stent stenoses were less than 50%. On DSA 2 images (obtained at follow-up), 95.7% of in-stent stenoses were graded as less than 50%. The difference between grading of stenoses on DSA and MR angiography images was 15.0% +/- 16.0% (minimum, 0.0%; maximum, 63.3%) for DSA 1 versus MR angiography 1 (statistically significant, p = 0.037) and 9.8% +/- 13.5% (minimum, 0.0%; maximum, 63.3%) for MR angiography 2 versus DSA 2 (not statistically significant, p = 0.355). CONCLUSION: Patency was correctly assessed for all stents on MR angiography. The quality of MR angiography regarding characterization of in-stent stenoses improved with time after stent placement. However, discrepancies of more than 60% between grading of lumen narrowing on DSA and MR angiography images occurred even at the 6-month follow-up. Thus, MR angiography is not yet a reliable technique for characterization of in-stent stenoses.

Adult↗
PubMed2004

Magnetic resonance imaging based colonography for diagnosis and assessment of diverticulosis and diverticulitis.

BACKGROUND AND AIMS: MRI-based colonography is a new minimally invasive imaging modality to assess the colon and abdomen. This new method which is applied mainly for polyp screening could be an integrative approach for colonic diverticulitis assessment. This study evaluated the feasibility of MRI-based colonography to assess diverticulosis or diverticulitis. PATIENTS AND METHODS: Fourteen consecutive patients with clinically suspected diverticulitis were examined by MRI colonography on a 1.5-T scanner. All patients underwent abdominal CT as gold standard. N-Butyl-scopalamin was given intravenously to reduce bowel peristalsis. After rectal administration of a T1-positive enema T1- and T2-weighted acquisitions with additional intravenous contrast were obtained. A 3D FLASH sequence was acquired for virtual colonography. The results were compared with CT and biological parameters such as white blood cell count and C-reactive protein. RESULTS: Of 56 bowel segments (sigmoid colon, descending colon, transverse colon, ascending colon) in all 14 patients 54 were assessed to have good to fair image quality. Having CT as standard of reference, all sigmoid diverticula were diagnosed based on MRI. Inflammation as judged by CT was identically assessed on MRI. 3D models of the colon revealed further diverticula in the remaining colon; additionally, the 3D models gave a comprehensive image for surgical planning. CONCLUSION: In our preliminary study MRI colonography revealed the same diagnosis as CT in all patients without ionizing radiation. Additionally, 3D-rendered models and virtual colonoscopy can be performed. This comprehensive 3D models could replace presurgical planning barium enema with concurrent assessment of the residual colon.

Adult↗
PubMed2004

Dose reduction in skeletal and chest radiography using a large-area flat-panel detector based on amorphous silicon and thallium-doped cesium iodide: technical background, basic image quality parameters, and review of the literature.

The two most frequently performed diagnostic X-ray examinations are those of the extremities and of the chest. Thus, dose reduction in the field of conventional skeletal and chest radiography is an important issue and there is a need to reduce man-made ionizing radiation. The large-area flat-panel detector based on amorphous silicon and thallium-doped cesium iodide provides a significant reduction of radiation dose in skeletal and chest radiography compared with traditional imaging systems. This article describes the technical background and basic image quality parameters of this 43 x 43-cm digital system, and summarizes the available literature (years 2000-2003) concerning dose reduction in experimental and clinical studies. Due to its high detective quantum efficiency and dynamic range compared with traditional screen-film systems, a dose reduction of up to 50% is possible without loss of image quality.

Cesium↗