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1.
Eur J Radiol ; 84(9): 1636-43, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26049958

ABSTRACT

Incidentally detected focal liver lesions are commonly encountered in clinical practice presenting a challenge in the daily department work flow. Guidelines for the management of incidental focal liver lesions have been published but comments, illustrations and recommendations regarding practical issues are crucial. The unique features of contrast-enhanced ultrasound in non-invasive assessment of focal liver lesion enhancement throughout the vascular phases in real-time has allowed an impressive improvement in the diagnostic accuracy of ultrasound. We highlight the additional benefit of contrast-enhanced ultrasound over conventional B-mode ultrasound imaging in detection, characterization, differential and final diagnosis of focal liver lesions, as well as for liver metastases screening. The current roles of cross-sectional imaging are explained in detail, with indications and limitations for each procedure. The advantages of CEUS, such as non-ionizing radiation exposure, cost benefits, non-iodinate contrast agents, and repeatability are also described ultimately improving patient management.


Subject(s)
Adenoma, Liver Cell/diagnostic imaging , Carcinoma, Hepatocellular/diagnostic imaging , Contrast Media , Image Enhancement , Liver Neoplasms/diagnostic imaging , Liver/diagnostic imaging , Adenoma, Liver Cell/pathology , Carcinoma, Hepatocellular/pathology , Humans , Liver/pathology , Liver Neoplasms/pathology , Magnetic Resonance Imaging , Tomography, X-Ray Computed , Ultrasonography
2.
Int J Occup Environ Med ; 4(1): 2-11, 2013 Jan.
Article in English | MEDLINE | ID: mdl-23279793

ABSTRACT

BACKGROUND: Noise, one of the major environmental nuisances, affects the learning ability of children negatively. OBJECTIVE: With the assumption that in the existing German 4-type school system children are exposed to various noise levels in each type of school, we investigated the association between children's school type and environmental noise level. METHODS: In this cross-sectional study, we included 550 children, primary and secondary school students, aged 8-12 years, and who lived in 4 Bavarian cities. The environmental noise level was assessed by personal 24-h dosimeter measurements. The associations of interest were assessed by linear regression. RESULTS: The average day noise level of 80.0 dB(A) was relatively high, exceeding the threshold level of 60 dB(A). In the model adjusted for sex, socioeconomic status (SES), and place of residence, noise level was significantly higher for primary schools by almost 2.3 dB(A); however, after additional adjustments for age, this association was distorted. The mean night noise level of 43.7 dB(A) was not associated with the school level. We could not find any significant differences in the noise level between different types of secondary schools. CONCLUSION: We found evidence that in Germany, children, especially of a younger age from primary school, are exposed to high noise levels during day in and outside the school environment. School administration and parents should work to make schools less noisy and more accomplished for learning to achieve a bright future for the children.


Subject(s)
Environmental Exposure/statistics & numerical data , Noise , Students , Age Factors , Child , Cross-Sectional Studies , Female , Germany , Humans , Male
3.
Endoscopy ; 41(8): 725-6, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19670143

ABSTRACT

We present our experience with contrast-enhanced ultrasound-guided percutaneous transhepatic cholangiodrainage in eight patients with obstructive jaundice and failure of conventional endoscopic retrograde cholangiography. The intraductal application of the ultrasound contrast agent led to sufficient cholangiography in all patients. In one patient, after accidental dislocation of the bile duct drain, the leakage could be detected by demonstration of the passage of contrast agent into the perihepatic peritoneal space. Further studies are necessary to evaluate this new technique in a larger numbers of patients.


Subject(s)
Cholangiography/methods , Drainage/methods , Jaundice, Obstructive/therapy , Bile Ducts, Intrahepatic/diagnostic imaging , Bile Ducts, Intrahepatic/pathology , Cholangiopancreatography, Endoscopic Retrograde , Contrast Media , Humans , Jaundice, Obstructive/diagnostic imaging , Phospholipids , Sulfur Hexafluoride , Ultrasonography , Video Recording
4.
Rofo ; 181(4): 332-8, 2009 Apr.
Article in German | MEDLINE | ID: mdl-19291602

ABSTRACT

PURPOSE: Spiral CT angiography (CTA) of the coronaries using low-pitch scanning and ECG-gated image reconstruction is a robust method for detecting or excluding relevant coronary plaque. However, the resulting dose exposure is considerable. The aim of the present study was to evaluate image quality and artifacts as well as to record dose values for sequential coronary CTA using a 128-slice scanner with a temporal resolution of 150 ms. MATERIALS AND METHODS: 20 patients with a regular heart rate and without contraindications for oral/I.V. beta blockers, who were referred for CTA of the coronaries for exclusion or detection of relevant plaques, were examined by sequential CTA with the following parameters: 120 kV, 200 ref mAs, collimation 2 x 64 x 0.6, table feed of 34.5 mm at a detector width of 38.4 mm. A total acquisition time of 380 ms per table position allowed for mild shifting of the reconstruction window within the cardiac cycle of +/- 5 %. 50 ml of contrast agent were injected at 5 ml/s followed by a 50 ml split bolus (20 % contrast). The individual start delay was determined by a test bolus scan (10 ml contrast + 50 ml saline flush at 5 ml/s). The image quality for each segment, coronary artery, and patient was determined on a 4-point scale. Dose values were estimated based on the individual dose length product as provided by the scanner's patient protocol. Artifacts were evaluated to determine the cause (calcium vs. motion). RESULTS: All patients received beta blocker pretreatment. The mean heart rate was 62 +/- 5 beats/min. 5 % (13 / 286) of all segments in 5 / 20 patients were rated as non-diagnostic. The mean dose length product was 213 mGy x cm, and the mean effective dose was 3.6 mSv. Calcifications were the major cause of non-diagnostic images. However breathing or other motion artifacts occurred as well. CONCLUSION: In select patients with effective heart rate control and thorough instruction for breath hold compliance, sequential CTA of the coronaries using a 128-slice scanner with a temporal resolution of 150 ms is technically feasible. The resulting effective dose values are clearly below those of spiral coronary CT scans.


Subject(s)
Body Burden , Cardiac-Gated Imaging Techniques/methods , Coronary Angiography/methods , Coronary Artery Disease/diagnostic imaging , Radiographic Image Enhancement/methods , Tomography, Spiral Computed/methods , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Pilot Projects , Radiometry , Relative Biological Effectiveness , Reproducibility of Results , Sensitivity and Specificity
5.
Rofo ; 180(4): 310-7, 2008 Apr.
Article in German | MEDLINE | ID: mdl-18499907

ABSTRACT

PURPOSE: To evaluate the technical applicability and accuracy of a navigation system for CT-guided interventional procedures in a phantom and a patient study. MATERIALS AND METHODS: A novel navigation tool (CAPPA IRAD, CAS innovations AG, Erlangen, Germany) was employed for CT-guided biopsies in a phantom and in patients. The entire system consists of a PC, navigation software, an optical tracking system and a patient frame. For the phantom study, a spine phantom in wax was used. The phantom as well as the patients were placed on the CT table in a stable position and fixed within a double vacuum device. The patient frame equipped with optical and CT markers was placed above the target region, followed by acquisition of a planning scan. All data were transferred to the navigation system inside the scanning room, and with the aid of the above mentioned navigation software, the biopsy pathway was planned. Hereafter, the needle holder was aligned accordingly, and a coaxial biopsy needle was pushed forward to the planned target. An additional control scan confirmed needle position, and the navigation software was used to evaluate the distance between the target and needle tip. RESULTS: In the phantom study (n = 60) the average deviation between the planned and documented needle tip position was 1.1 mm. In the clinical study (n = 15), we performed biopsies of the lung, the mediastinal area, the pancreas and liver and some bone biopsies as well as a therapeutic nerve root infiltration. 12 of 15 cases required oblique needle access. In 9 / 15 cases merely a single planning and control scan were required, whereas in 5 / 15 cases additional safety or correction scans were performed. In the case of pancreas biopsy, the lesion (diameter 1 centimeter) visible during the arterial phase only could not be punctured even following repeated corrections due to severe breathing artifacts and pronounced peristaltic movement of the adjacent bowel. The time between planning CT and correct needle position was about 30 minutes. CONCLUSION: The navigation system allows for safe interventions in case of angulated needle access with high accuracy and little tissue trauma. However, insufficient corrections for respiration movement constitute a substantial limitation of the tool.


Subject(s)
Phantoms, Imaging , Surgery, Computer-Assisted/instrumentation , Tomography, X-Ray Computed/instrumentation , Anesthesia, Local/instrumentation , Artifacts , Biopsy, Needle/instrumentation , Bone and Bones/pathology , Contrast Media/administration & dosage , Equipment Design , Esophagus/pathology , Humans , Liver/pathology , Lung/pathology , Neoplasms/pathology , Pancreas/pathology , Sensitivity and Specificity , Software , Spinal Nerve Roots/drug effects , Spine/pathology
7.
AJNR Am J Neuroradiol ; 28(1): 104-10, 2007 Jan.
Article in English | MEDLINE | ID: mdl-17213434

ABSTRACT

BACKGROUND AND PURPOSE: We prospectively evaluated the influence of different imaging techniques (time-of-flight MR angiography [TOF-MRA], contrast-enhanced MR angiography [CE-MRA], multisection CT angiography [CTA]) and postprocessing methods (maximum intensity projection [MIP], multiplanar reformation [MPR]) on carotid artery stenosis grading. MATERIALS AND METHODS: Fifty patients (34 men, 16 women) with symptomatic stenosis of the internal carotid artery were examined with a 16-section spiral CT and a 1.5T MR unit. Two MRA techniques were applied: 3D-TOF and CE-MRA. MPR was used for postprocessing with all modalities; MIP was used only with MRA. Four readers measured and calculated the percentage diameter stenosis independently according to NASCET criteria. The Wilcoxon test was used to measure interobserver variability, and the Friedman test was used to test the null-hypothesis of equality of the modalities. RESULTS: The hypothesis for global equality was rejected (P < .001). TOF-MRA and CTA assessed with MPR showed the highest concordance (difference, 0.6%; confidence interval [CI], -3.0, 4.3%), and CE-MRA with MIP and CTA showed the lowest concordance in stenosis grading (difference, 7.0%; CI, 3.4, 10.6%). MPR resulted in lower degrees of stenosis than MIP for both MRA sequences, although not statistically significant (CE, -3.0%; CI, -6.6, 0.6%; TOF, -2.2%; CI, -5.8, 1.4%). When only studies with good or excellent image quality were considered, the differences decreased, but the trends remained. CONCLUSION: Stenosis grading is dependent on the examination method and postprocessing technique. CTA and TOF-MRA evaluated with MPR revealed highest concordance.


Subject(s)
Carotid Artery, Internal , Carotid Stenosis/diagnosis , Cerebral Angiography , Image Processing, Computer-Assisted , Imaging, Three-Dimensional , Magnetic Resonance Angiography , Tomography, Spiral Computed , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Observer Variation , Prospective Studies , Sensitivity and Specificity
8.
Radiologe ; 45(7): 608-17, 2005 Jul.
Article in German | MEDLINE | ID: mdl-16059657

ABSTRACT

The broad introduction of multi-slice CT by all major vendors in 1998 was a milestone with regard to extended volume coverage, improved axial resolution and better utilization of the tube output. New clinical applications such as CT-examinations of the heart and the coronary arteries became possible. Despite all promising advances, some limitations remain for 4-slice CT systems. They come close to isotropic resolution, but do not fully reach it in routine clinical applications. Cardiac CT-examinations require careful patient selection. The new generation of multi-slice CT-systems offer simultaneous acquisition of up to 16 sub-millimeter slices and improved temporal resolution for cardiac examinations by means of reduced gantry rotation time (0.4 s). In this overview article we present the basic technical principles and potential applications of 16-slice technology for the example of a 16-slice CT-system (SOMATOM Sensation 16, Siemens AG, Forchheim). We discuss detector design and dose efficiency as well as spiral scan- and reconstruction techniques. At comparable slice thickness, 16-slice CT-systems have a better dose efficiency than 4-slice CT-systems. The cone-beam geometry of the measurement rays requires new reconstruction approaches, an example is the adaptive multiple plane reconstruction, AMPR. First clinical experience indicates that sub-millimeter slice width in combination with reduced gantry rotation-time improves the clinical stability of cardiac examinations and expands the spectrum of patients accessible to cardiac CT. 16-slice CT-systems have the potential to cover even large scan ranges with sub-millimeter slices at considerably reduced examination times, thus approaching the goal of routine isotropic imaging.


Subject(s)
Cardiovascular Diseases/diagnostic imaging , Imaging, Three-Dimensional/instrumentation , Imaging, Three-Dimensional/methods , Radiographic Image Enhancement/instrumentation , Radiographic Image Enhancement/methods , Tomography, Spiral Computed/instrumentation , Tomography, Spiral Computed/methods , Equipment Design , Equipment Failure Analysis , Humans , Radionuclide Imaging , Reproducibility of Results , Sensitivity and Specificity , Technology Assessment, Biomedical
11.
Z Gastroenterol ; 42(8): 739-42, 2004 Aug.
Article in English | MEDLINE | ID: mdl-15314727

ABSTRACT

INTRODUCTION: To date, only few reports are available on patients with esophageal carcinoma containing a tracheoesophageal fistula under chemotherapy. CASE REPORT: A 56-year-old patient presented to the hospital with a stenosing squamous cell carcinoma of the esophagus containing a tracheoesophageal fistula 3 cm above the carina. After placement of a Port-a-Cath and adequate hydration he received weekly 500 mg/m (2) i. v. folinic acid (FA) as a 1 - 2-hour infusion and 2000 mg/m (2) 5-fluorouracil (5-FU) as a 24-hour infusion (24-h inf.) (AIO regimen) with prior application of bi-weekly 50 mg/m (2) i. v. cisplatin. A tracheal Y-Dumont metallic stent was inserted prior to initiating systemic treatment. The patient's alimentation was completely parenteral. After three cycles of chemotherapy (six months) the patient revealed complete remission (CR) with closure of the tracheoesophageal fistula. The tracheal Y-Dumont stent could be removed and the patient had oral alimentation restored. 29 months after initiating treatment he is without evidence of disease. CONCLUSION: Patients with esophageal carcinoma containing a tracheoesophageal fistula might benefit from chemotherapy and should not be generally excluded from systemic treatment.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Cisplatin/administration & dosage , Esophageal Neoplasms/complications , Esophageal Neoplasms/drug therapy , Tracheoesophageal Fistula/drug therapy , Tracheoesophageal Fistula/etiology , Antineoplastic Agents/administration & dosage , Disease-Free Survival , Esophageal Neoplasms/diagnosis , Fluorouracil/administration & dosage , Humans , Leucovorin/administration & dosage , Male , Middle Aged , Remission Induction/methods , Survivors , Tracheoesophageal Fistula/diagnosis , Treatment Outcome
12.
Rofo ; 176(6): 862-9, 2004 Jun.
Article in German | MEDLINE | ID: mdl-15173981

ABSTRACT

PURPOSE: To investigate the potential of dose reduction in multislice spiral CT (MSCT) with automatic exposure control. MATERIALS AND METHODS: The study was performed on a Sensation 4 multislice scanner. This prototype implementation analyzed the distribution of the attenuation along the z-axis in the lateral and sagittal directions of the digital radiogram. Depending on this distribution of the attenuation, the tube current (mA) is defined for every tube rotation. In addition, the tube current was modulated during each tube rotation. First, a three step oval water phantom was measured to evaluate the potential of this method with respect to dose reduction and image quality. In a patient study (n = 26), four different scan regions (shoulder, thorax, abdomen, pelvis) were examined and dose (mAs) and image quality evaluated in comparison to examinations with a standard protocol for these regions in adults and a weight-adjusted standard protocol in children. The image quality was classified in consensus as good, sufficient and poor image quality. RESULTS: By adapting and modulating the tube current, we substantially reduced the variation of noise in one spiral scan and in one scan region of our patient collective. The dose (average mAs) was reduced by 31 % to 66 % in children (mean 44 %) and between 35 % and 64 % in adults (mean 53 %), depending on the scan region. The image quality was substantially improved in regions with high attenuation and did not suffer in low attenuation regions. CONCLUSION: The dose can be reduced substantially by an automatic exposure control including angular tube current modulation with the same or improved image quality.


Subject(s)
Radiation Dosage , Spine/diagnostic imaging , Tomography, Spiral Computed/methods , Abdomen , Adult , Automation , Child , Humans , Phantoms, Imaging , Thorax
13.
Rofo ; 175(11): 1572-6, 2003 Nov.
Article in German | MEDLINE | ID: mdl-14610712

ABSTRACT

PURPOSE: To evaluate the potential of raw data-based multidimensional adaptive filtering (MAF) by determining its effects on image noise and image quality in multi-slice spiral CT (MSCT) of the pelvis. MATERIALS AND METHODS: Fifty patients with rectal and bladder cancer were examined with MSCT using a high-resolution protocol. Reconstructions were performed with dedicated reconstruction software and a standard algorithm, both without and with MAF, with four different modification fractions selected from 5 % to 20 %. The noise was measured at six anatomic sites of the pelvis. Image quality and image noise were rated on a 5-point-scale. RESULTS: Modification fractions of 15 % (15 % MAF) and 20 % (20 % MAF) significantly reduced the noise level at all measurement points in comparison with lower modification fractions (p < 0.05). Overall quality of the reconstructed images was rated better with 15 % MAF and 20 % MAF than with other modification fractions (p < 0.05). No further improvement of the image quality was observed by changing from 15 % MAF to 20 % MAF (p > 0.05). 15 % MAF achieved a mean noise reduction of 33 %. All examinations showed an improved visualization of the rectal wall and perirectal lymph nodes. CONCLUSIONS: MAF improves the image quality by reducing the noise level and by removing noise structures. This technique offers new perspectives to radiation dose reduction in CT.


Subject(s)
Pelvis/diagnostic imaging , Tomography, Spiral Computed/methods , Humans , Image Processing, Computer-Assisted , Regression Analysis , Reproducibility of Results , Sensitivity and Specificity , Tomography, Spiral Computed/standards
14.
Oncology ; 64(2): 131-8, 2003.
Article in English | MEDLINE | ID: mdl-12566910

ABSTRACT

PURPOSE: To evaluate the efficacy and safety of neoadjuvant treatment comprising weekly high-dose 5-fluorouracil (5-FU) as a 24-hour infusion, folinic acid (FA) and biweekly oxaliplatin (L-OHP), followed by metastatic resection in patients with primarily resectable liver metastases of colorectal cancer (CRC). PATIENTS AND METHODS: 20 patients with primarily resectable liver metastases of CRC were enrolled in a prospective phase II study. On an outpatient basis, the patients received a treatment regimen comprising biweekly 85 mg/m(2) L-OHP in the form of a 2-hour intravenous infusion and 500 mg/m(2) FA as a 1- to 2-hour intravenous infusion, followed by 2,600 mg/m(2 ) 5-FU administered as a 24-hour intravenous infusion once weekly. A single treatment cycle comprised one infusion per week during a period of 6 weeks followed by a 2-week rest. Two cycles were administered, with a third being added when the treatment was well tolerated. Thereafter, curative resection of the liver metastases was attempted, and the patients were followed up. RESULTS: After neoadjuvant therapy, 2 of the original 20 patients showed complete remission (CR; 10%) and 18 patients partial remission (PR; 90%). As the main symptom of toxicity, diarrhea (CTC toxicity grade 3-4) was observed in 6 patients (30%), followed by vomiting in 3 patients (15%). The curative resectability rate was 80% (16 of 20). In 9 of 18 patients (50%) undergoing surgical intervention, mild postoperative complications, mainly wound healing disturbances (n = 5), occurred. No postoperative mortality was observed. Over a median follow-up of 23 months (12-38) 6 of 16 curatively resected patients developed distant metastases and 1 patient a local pelvic recurrence. The 2-year disease-free survival rate was 52% and the 2-year cancer-related survival rate 80%. CONCLUSION: The neoadjuvant treatment with weekly high-dose 5-FU in the form of a 24-hour infusion combined with FA and L-OHP is very effective and well tolerated. Surgical morbidity does not appear to be increased by the neoadjuvant treatment.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Colorectal Neoplasms/pathology , Liver Neoplasms/drug therapy , Liver Neoplasms/surgery , Neoadjuvant Therapy , Aged , Antimetabolites, Antineoplastic/administration & dosage , Chemotherapy, Adjuvant , Drug Administration Schedule , Female , Fluorouracil/administration & dosage , Humans , Leucovorin/administration & dosage , Liver Neoplasms/diagnostic imaging , Liver Neoplasms/secondary , Male , Middle Aged , Neoadjuvant Therapy/methods , Organoplatinum Compounds/administration & dosage , Oxaliplatin , Survival Analysis , Tomography, X-Ray Computed , Treatment Outcome
15.
Biomed Tech (Berl) ; 47 Suppl 1 Pt 2: 782-5, 2002.
Article in German | MEDLINE | ID: mdl-12465302

ABSTRACT

Multi-slice spiral CT (MSCT) permits the detection of coronary stenoses. We investigated the influence of the patient's heart rate (HR) during the scan on stenosis detection and the presence of motion artifacts. In 100 patients MSCT was performed and retrospectively ECG-gated cross-sectional images were reconstructed. 115 of 400 coronary arteries (29%) were unevaluable due to motion artifacts (84/115) or other reasons (31/115). In evaluable arteries, sensitivity was 91% (51/56 high grade stenoses detected), specificity was 89%. With increasing HR, the number of unevaluable arteries increased and overall sensitivity for stenosis detection decreased from 62% (HR < or = 70 bpm) to 33% (HR > 70 bpm). MSCT permits detection of coronary stenoses, but evaluability and accuracy decrease with increasing HR.


Subject(s)
Artifacts , Coronary Stenosis/diagnostic imaging , Electrocardiography/methods , Heart Rate/physiology , Image Processing, Computer-Assisted/methods , Tomography, Spiral Computed/methods , Aged , Coronary Angiography , Coronary Stenosis/physiopathology , Female , Humans , Male , Middle Aged , Sensitivity and Specificity
16.
HNO ; 50(10): 906-19, 2002 Oct.
Article in German | MEDLINE | ID: mdl-12376905

ABSTRACT

Diseases of the petrous bone should now be diagnosed by means of high-resolution multislice spiral computed tomography (MSCT) and/or magnetic resonance imaging (MRI). The first step in the process of diagnosis, however, must be conventional X-ray photographs (according to Schüller, Mayer, Stenvers) for screening purposes, because of the high cost of the other procedures mentioned. Because of the excellent imaging of bone structures with MSCT, this technique is especially suitable for the diagnosis both of acquired pathologies and of congenital abnormalities of the external auditory meatus, the middle ear and the mastoid, of trauma-induced pathologies of the entire petrous bone, and of osteogenic diseases. MRI is the method of choice for examination of the labyrinthine system, the interior auditory meatus and the cerebellopontine angle because it gives much the best depiction of soft tissue. Sometimes when questions remain unsolved after computed tomography (CT) examination of the middle ear MRI can be applied to complement CT, and it can yield additional information. Lesions affecting the apex of the petrous pyramid should be examined by MRI. High-resolution CT through the bone window and thin-layer MRI are both components of the presurgical diagnosis before cochlear implant (CI) surgery. For postoperative monitoring a conventional transorbital X-ray of the petrous bone is sufficient; CT is indicated only in complicated cases, and MRI is absolutely contraindicated after CI.


Subject(s)
Cochlear Implants , Ear Diseases/diagnosis , Ear Neoplasms/diagnosis , Magnetic Resonance Imaging , Petrous Bone/pathology , Skull Fractures/diagnosis , Skull Neoplasms/diagnosis , Tomography, Spiral Computed , Artifacts , Ear Diseases/therapy , Ear Neoplasms/therapy , Humans , Image Enhancement , Image Processing, Computer-Assisted , Imaging, Three-Dimensional , Petrous Bone/injuries , Sensitivity and Specificity , Skull Fractures/therapy , Skull Neoplasms/therapy
17.
Rofo ; 174(9): 1165-9, 2002 Sep.
Article in German | MEDLINE | ID: mdl-12221577

ABSTRACT

PURPOSE: To evaluate a novel multislice CT system (16-slice-spiral-CT scanner) for the diagnosis of carotid artery stenosis. MATERIAL AND METHODS: Five patients with symptomatic atherosclerotic disease of the carotid arteries were examined with a 16- slice-spiral-CT scanner. Collimation was 16 x 0.75 mm, table speed 36 mm/s (pitch of 1.5), rotation time 0.5 s, tube current was 160 eff.mAs at 120 kV. 60 ml of contrast material were injected with a power injector followed by a saline flush. The start delay was measured with test bolus method (20 ml CM). Interactive multiplanar reformation (iMPR) and thin slab MIP as well as volume rendering were used for image evaluation and presentation. RESULTS: Scan time was 9 s for a range of 300 mm. This allowed imaging the whole length of the carotid artery (aortic arch to circle of Willis) in a true arterial phase. Pulsation artefacts did not impair the evaluation of the vessels at the level of the aortic arch. Overall image quality of both "source images" and 3D-reconstructions was excellent, due to a reduced voxel size of 0.03 mm (3). Image evaluation and postprocessing (iMPR, MIP) was done within 15 min. iMPR was highly accurate for demonstrating plaque morphology and determining the percentage of the stenosis. CONCLUSION: For the first time, true arterial phase images of the entire carotid artery with high spatial resolution could be acquired using a 16-slice-spiral-CT scanner. This method offers the potential to replace catheter angiography in the evaluation of carotid artery stenosis.


Subject(s)
Carotid Stenosis/diagnostic imaging , Cerebral Angiography/methods , Image Processing, Computer-Assisted , Imaging, Three-Dimensional , Intracranial Arteriosclerosis/diagnostic imaging , Radiographic Image Enhancement/methods , Tomography, X-Ray Computed/methods , Blood Flow Velocity/physiology , Carotid Arteries/diagnostic imaging , Circle of Willis/diagnostic imaging , Contrast Media/administration & dosage , Dose-Response Relationship, Drug , Humans
18.
Rofo ; 174(7): 893-7, 2002 Jul.
Article in German | MEDLINE | ID: mdl-12101481

ABSTRACT

PURPOSE: To examine the diagnostic accuracy of pancreatic lesions using mangafodipir-trisodium (Mn-DPDP) enhanced MR imaging. The imaging results were correlated with the histopathological results. MATERIAL AND METHODS: 40 patients with suspicion of pancreatic carcinoma were examined with MRI before and after i. v. administration of Mn-DPDP (Philips Gyroscan ACS NT 1.5 T, phased array body-coil: TSE T 2 with and without SPIR, TR 2000 ms, TE 120ms; FFE T 1 breathhold, TR 115 ms, TE 4.6 ms; MRCP, TR 6000 ms, TE 1200 ms; Teslascan i. v. 5 micromol Mn/kg; FFE T 1 breathhold SPIR, TR 140 ms, TE 4,6 ms). Two observers evaluated in consensus the number and characteristics of focal pancreatic lesions. The MR findings were correlated with histopathological findings retrospectively. RESULTS: The following lesions were found: adenocarcinoma (19), pancreatitis (8), adenocarcinoma within pancreatitis (3), insulinoma (2), hematoma (1), papillitis stenosans (1), signet ring cell carcinoma (1), metastasis of rectal carcinoma (1), papillary mesothelioma (1). In three patients there was no pathological finding. Mn-DPDP enhanced MRI showed a sensitivity of 100 % and a specificity of 56 %. CONCLUSION: Mn-DPDP enhanced MRI in conjunction with MRCP showed a high sensitivity for the detection of pancreatic lesions. However, the specificity is low, thus recommending Mn-DPDP enhanced MRI only as a complementary imaging method.


Subject(s)
Ampulla of Vater , Common Bile Duct Neoplasms/diagnosis , Contrast Media , Edetic Acid/analogs & derivatives , Image Enhancement , Magnetic Resonance Imaging , Pancreatic Neoplasms/diagnosis , Pancreatitis/diagnosis , Pyridoxal Phosphate/analogs & derivatives , Ampulla of Vater/pathology , Biopsy, Needle , Common Bile Duct Neoplasms/pathology , Humans , Pancreatic Neoplasms/pathology , Pancreatitis/pathology , Sensitivity and Specificity
19.
Rofo ; 174(6): 721-4, 2002 Jun.
Article in German | MEDLINE | ID: mdl-12063601

ABSTRACT

PURPOSE: First evaluation of image quality of a new 16-slice multidetector-row computed tomography (MDCT) for the assessment of coronary artery disease and lesion detection of the coronary arteries. MATERIALS AND METHODS: On a newly developed 16-slice CT scanner (SOMATOM Sensation 16, Siemens, Forchheim, Germany) a calcium score as well as a contrast-enhanced CT angiography (CTA) were performed on 4 patients with retrospective ECG-gating and a gantry rotation time of 420 ms to exclude or follow-up coronary heart disease. CTA was performed after injecting 120 ml contrast media intravenously. After medication with a ss-Blocker, the heart rate was between 55 and 67 bpm. RESULTS: The scan time for calcium score was 12 s, for CTA 18 s (scan range 15 and 12 cm, respectively). Volume score was between 0 and 256.4. In the CT angiography the entire coronary tree could be visualized in all patients up to the very distal subsegmental branches. In two patients a complete occlusion of the RCA and the LAD were depicted, respectively. In one of these patients, a large aneurysm of the left anterior ventricular wall was also delineated. CONCLUSION: Considering our first experiences with the new 16-slice technology, an excellent visualization of the entire coronary tree including the very distal and side branches due to substantially increased spatial resolution seems to be achievable. In these patients the acquired image quality raises the hope for improved, non-invasive cardiac diagnostics. In larger studies, the clinical impact of this new technology needs to be further investigated.


Subject(s)
Coronary Angiography , Coronary Artery Disease/diagnostic imaging , Image Processing, Computer-Assisted , Imaging, Three-Dimensional , Radiographic Image Enhancement/instrumentation , Tomography, X-Ray Computed/instrumentation , Aged , Calcinosis/diagnostic imaging , Female , Heart Aneurysm/diagnostic imaging , Humans , Male , Middle Aged , Sensitivity and Specificity
20.
Klin Monbl Augenheilkd ; 218(10): 688-90, 2001 Oct.
Article in German | MEDLINE | ID: mdl-11706386

ABSTRACT

BACKGROUND: Vaccinations are preventive measures against serious infections. In relation to the number of vaccinations per year, the incidence of severe complications is extremely low. PATIENT: Two weeks after vaccinations against hepatitis A, hepatitis B and yellow fever in preparation for a trip to Africa a 21-year-old woman experienced an acute and irreversible loss of vision to 0,05 and nasal visual field defect in the left eye. Whereas vision acuity did not recover the scotoma disappeared within 6 weeks. Cerebrospinal fluid showed a lymphocytic pleocytosis. Oligoglonale bands were absent. Pathological parameters were not presented in the serum. The MRI showed a hyperintense thickening of optic nerve,as well as a hyperintense focus in right temporal side using the T(2)W-Sequence. CONCLUSION: Only few cases have been reported with neurological complications, such as encephalitis, following vaccinations each of the above mentioned. As no other causes for the inflammation were found, the optic nerve involvement must have been caused by the vaccination. Which of the three vaccinations caused encephalitis can not be classified.


Subject(s)
Anti-Inflammatory Agents/therapeutic use , Encephalomyelitis, Acute Disseminated/etiology , Hepatitis A Vaccines/adverse effects , Hepatitis B Vaccines/adverse effects , Optic Neuritis/chemically induced , Yellow Fever Vaccine/adverse effects , Adult , Female , Humans , Optic Neuritis/drug therapy , Steroids , Treatment Outcome , Visual Acuity , Visual Fields
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