Biomedical subjects

R Bruening

Publications and source records attributed to R Bruening.

18 recordsLinked to original sources

PubMed2001

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy: decrease in regional cerebral blood volume in hyperintense subcortical lesions inversely correlates with disability and cognitive performance.

BACKGROUND AND PURPOSE: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an arteriopathic syndrome related to a genetic defect on chromosome 19. Characteristic changes in CADASIL can be observed onT2-weighted MR images in the subcortical white matter. The purpose of this study was to measure changes of regional cerebral blood volume (rCBV) with dynamic contrast-enhanced MR imaging and to correlate the changes to disability and cognitive performance. METHODS: We obtained rCBV measurements of 24 individuals with proven CADASIL on a 1.5-T MR imaging unit. A susceptibility-weighted MR imaging sequence was used for bolus tracking. Principles of the indicator dilution theory were applied to estimate values of absolute rCBV (mL/100 g). Disability was determined by using the Rankin scale, and overall cognitive performance was assessed by using the Mini-Mental State Examination. RESULTS: The mean rCBV in the subcortical white matter that was hyperintense on the T2-weighted images (2.7 +/- 0.8 mL/100 g) was significantly lower than the rCBV in the white matter that appeared normal on the T2-weighted images (4.4 +/- 1.3 mL/100 g) (P <.05). The mean rCBV in the gray matter was within the normal range (8.3 +/- 1.7 mL/100 g). Both cognitive impairment and disability negatively correlated with rCBV in the subcortical white matter that was hyperintense (P <.05) but not with rCBV in the normal appearing white matter. rCBV did not correlate with age. CONCLUSION: rCBV measured in the hyperintense subcortical white matter in individuals with CADASIL was decreased and inversely correlated with disability and cognitive impairment.

Adult↗

PubMed2000

Tumors of the cardiac valves: imaging findings in magnetic resonance imaging, electron beam computed tomography, and echocardiography.

We describe the findings from various cross-sectional imaging modalities in patients with cardiac valve adherent masses. The techniques are discussed, and imaging findings are compared with the results of cardiac surgery. All three patients had neurological symptoms and/or cardiac murmurs. Transthoracic and/or transesophageal echocardiography revealed the cardiac mass in all three. For differentiation of thrombus and cardiac neoplasm magnetic resonance imaging (MRI) was also performed in all three patients and electron-beam computed tomography (EBCT) in two. Fast segmented cine gradient-echo MRI techniques provided mass depiction in all patients, while T1-weighted spin-echo imaging failed in mass detection in one patient. None of the patients showed evidence of valve regurgitation or stenosis in flow sensitive cine MRI. EBCT excluded mass calcifications in both patients and reliably demonstrated the valve attached lesions. Although echocardiography is the modality of choice in evaluating cardiac masses and especially valve attached masses, MRI and EBCT provide additional information about tissue characteristics and allows an excellent overview of the cardiac and paracardiac morphology. Fast segmented cine gradient-echo MRI is especially able to depict even small tumors attached to rapidly moving cardiac valves, and valve competence can be easily assessed within the same examination.

Adult↗

PubMed2000

Visualization and quantification of coronary calcifications with electron beam and spiral computed tomography.

This contribution reviews the pathology and morphology of coronary calcifications. It summarizes the indications for investigation of the coronary arteries. The standard protocols for scan acquisition using electron beam and conventional computed tomography are described as well as various methods for evaluation such as the traditional Agatston scoring method and the newer three-dimensional scoring algorithms. Guidelines for interpreting scores are also reviewed. Major limitations of the reproducibility of the calcium score measurement are summarized. Future aspects of multirow-detector spiral computed tomography with retrospective electrocardiographic triggering for quantifying coronary calcium are discussed.

Calcinosis↗

PubMed2000

Pulmonary embolism: comprehensive diagnosis by using electron-beam CT for detection of emboli and assessment of pulmonary blood flow.

PURPOSE: To comprehensively assess thoracic anatomy and pulmonary microcirculation in pulmonary embolism by using computed tomographic (CT) angiography of the pulmonary arteries combined with functional CT imaging of blood flow. MATERIALS AND METHODS: Twenty-two patients suspected of having acute pulmonary embolism underwent contrast material-enhanced thin-section electron-beam CT angiography of the pulmonary arteries. In addition, in each patient, a dynamic multisection blood flow CT study was performed on a 7.6-cm lung volume with electrocardiographic gating. Pulmonary blood flow was calculated, and perfusion parameters were visualized on color-coded maps. The color-coded maps and CT angiograms were independently evaluated, segment by segment, by two readers for perfusion deficits and the presence of clots, respectively. The results were compared. RESULTS: Mean pulmonary blood flow was 0.63 mL/min/mL in the occluded segments versus 2.27 mL/min/mL in the nonoccluded segments (P: =.001). The sensitivity and specificity of perfusion maps for the presence of segmental pulmonary embolism compared with those of CT angiography were 75.4% and 82.3%, respectively, with positive and negative predictive values of 79.6% and 84.7%, respectively. The false-negative findings were caused mainly by partial occlusion of vessels. In eight patients, a substantial alternative or additional pathologic entity was diagnosed. CONCLUSION: By combining CT angiography and dynamic CT imaging, a comprehensive and noninvasive diagnosis of thoracic structure and function is feasible with a single modality.

Acute Disease↗

PubMed2000

Helical and single-slice conventional CT versus electron beam CT for the quantification of coronary artery calcification.

OBJECTIVE: We compared electron beam CT with conventional CT to determine the best method for the assessment of the coronary calcium score. We used conventional CT to examine symptomatic and asymptomatic patients suspected of having coronary artery disease. SUBJECTS AND METHODS: One hundred sixty male patients underwent electron beam CT and helical CT with a pitch of 1 (n = 30) and 2 (n = 30) and using a single-slice mode with (n = 50) and without (n = 50) prospective ECG triggering. In another 50 patients, we determined reproducibility for repeated scanning using electron beam CT. For all images, we derived the calcium score according to the Agatston method. We performed regression analysis and determined mean variability. Mean variability was calculated as the ratio of the absolute difference to the mean of the corresponding calcium scores. RESULTS: The correlation coefficients for electron beam CT and all conventional CT modes were very high (range, 0.93-0.98). The mean variability was highest in the helical mode with a pitch of 2 (61.4%) and lowest for the single-slice mode with prospective ECG triggering (25.4%). For repeated electron beam CT, the correlation coefficient and mean variability were 0.99 and 22.1%, respectively. CONCLUSION: ECG-triggered single-slice conventional CT had the best agreement with electron beam CT calcium scores.

Calcinosis↗

PubMed2000

Effects of three different doses of a bolus injection of gadodiamide: assessment of regional cerebral blood volume maps in a blinded reader study.

BACKGROUND AND PURPOSE: Reconstruction of first-pass bolus information to derive regional cerebral blood volume (rCBV) maps is commonly performed in many centers; however, various protocols with different doses of paramagnetic contrast injections have been reported. We evaluated the dose dependency of rCBV maps in a brain tumor population by using three different doses of gadodiamide injection to evaluate their diagnostic accuracy in blinded reader sessions. METHODS: Eighty-three patients with intraaxial brain tumors (72 gliomas) were studied at three centers and randomized to receive a bolus injection of 0.1, 0.2, or 0.3 mmol/kg per body weight of gadodiamide. rCBV maps were generated from T2*-weighted gradient-echo echoplanar sequences at 1.5 T. Data processing was performed according to the indicator dilution theory. RESULTS: The mean contrast-to-noise ratio (CNR) was significantly different between gadodiamide doses of 0.1 and 0.2 mmol/kg (CNR = 8.7 and 15.7) and between 0.1 and 0.3 mmol/kg (CNR = 17.7). No significant difference was found between doses of 0.2 and 0.3 mmol/kg. Sensitivity for the differentiation of benign and malignant brain tumors was 80%, 95%, and 91%, and specificity was 45%, 54%, and 43% by blinded readings at 0.1, 0.2, and 0.3 mmol/ kg, respectively, as compared with histologic findings. Nonblinded readings had a sensitivity of 83%, 100%, and 90% and a specificity of 82%, 100%, and 73% at 0.1, 0.2, and 0.3 mmol/kg, respectively. CONCLUSION: A dose of 0.2 mmol/kg of gadodiamide is recommended for reconstruction of rCBV maps if data are acquired with the T2*-weighted protocol described.

Blood Volume↗

PubMed1999

MR measurement of regional relative cerebral blood volume in epilepsy.

The purpose of this study was to evaluate the utility of magnetic resonance (MR) relative cerebral blood volume (rCBV) maps for studying regional hemodynamic changes in interictal and ictal epilepsy patients. Ten epilepsy patients were examined on a 1.5 T MR system. Nine patients were investigated interictally and one patient ictally. In the nine interictal patients, the dynamic plane was defined coronally through the hippocampus symmetrically. For the ictal patient, an axial dynamic plane was defined and the patient was scanned during seizure. Positron emission tomography (PET) studies were performed in 8 of the 10 patients. Lower rCBV of the left hippocampus was predicted by rCBV maps in seven of the nine interictal patients. The mean ratios of rCBV were 1.96 for left hippocampus/white matter and 2.49 for right hippocampus/white matter. The difference between these two ratios is statistically significant (P = 0.01, t-test). In two of the nine interictal temporal lobe epilepsy patients, lower rCBV areas were observed in the right hippocampus. In the ictal patient, the regional rCBV map demonstrated increased blood volume in the lesions. In eight of eight patients who underwent PET studies, MR rCBV findings were consistent with PET findings. The results show that regional hemodynamic changes in epilepsy can be evaluated with dynamic contrast-enhanced MR imaging. MR rCBV maps are sensitive to characterize seizure foci both ictally and interictally.

Adult↗

PubMed1999

Detection and quantification of coronary artery calcification with electron-beam and conventional CT.

To identify patients with increased risk of having coronary artery disease (CAD), electron-beam computed tomography (EBCT) was used for years for quantifying calcifications of the coronary arteries. The first direct comparison between EBCT and conventional CT was performed to determine the reliability of widely available conventional CT for the assessment of the coronary calcium score. Fifty male patients with suspected CAD were investigated with both modalities, EBCT and conventional 500-ms non-spiral partial scan CT. Scoring of the coronary calcification was performed according to the Agatston method. Forty-two of these patients underwent coronary angiography for the assessment of significant luminal narrowing. The correlation coefficient of the score values of both modalities was highly significant (r = 0.982, p < 0.001). The variability between the two modalities was 42%. Mean calcium score in patients with significant coronary luminal narrowing (n = 37) was 1104 +/- 1089 with EBCT and 1229 +/- 1327 with conventional CT. In patients without luminal narrowing (n = 5) mean calcium score was 73 +/- 57 with EBCT and 26 +/- 35 with conventional CT. Although images of the heart from conventional CT may suffer from cardiac motion artifacts, conventional CT has the potential to identify patients with CAD with accuracy similar to EBCT.

Artifacts↗

PubMed1999

Muscle and skin biopsies are a sensitive diagnostic tool in the diagnosis of CADASIL.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a microangiopathic syndrome. Although the defective gene has been identified, genetic analysis may be effort some due to its large size and various mutations. Providing a reliable diagnostic marker would therefore be helpful. Electron microscopy has revealed characteristic electron-dense granular deposits in the basal lamina of vessels of patients with CADASIL. We investigated the sensitivity of skin and muscle biopsies for diagnosing CADASIL. We examined 30 family members of three unrelated German families affected by CADASIL. In 14 of the 21 affected individuals we performed skin and muscle biopsies; two patients were clinically asymptomatic. Under electron microscopy all muscle and skin biopsy specimens showed patches of granular and electron-dense material in the basal layer of both arterioles and capillaries. These findings confirm that general microangiopathy is a typical feature of this syndrome and is present in the early phase of the disease with or without clinical manifestation. Thus, as electron microscopy of skin biopsy specimens can establish the diagnosis of CADASIL with high certainty, it may be considered the method of first choice.

Adult↗

PubMed1999

Comparison of the diagnostic information in relative cerebral blood volume, maximum concentration, and subtraction signal intensity maps based on magnetic resonance imaging of gliomas.

RATIONALE AND OBJECTIVES: The authors investigate the validity of regional relative cerebral blood volume (rCBV) versus maximum concentration and subtraction signal intensity (SI) maps using simple reconstruction modes in patients with gliomas. METHODS: Twenty-five patients were studied using a 1.5 T magnetic resonance imaging scanner. To calculate the rCBV map, the magnetic resonance susceptibility effect SI/time curves were first transformed into concentration/time curves; then a gamma-variate function was fitted and the area under the curve was integrated. From the concentration/time data, the maximum concentration (MAX) maps were calculated pixel per pixel as the maximum peak amplitude of the concentration/time curve. Subtraction (SUB) maps are a result of simple image subtraction of pixelwise baseline SI minus the highest peak of susceptibility change pixel per pixel. Region of interest means SI measurement of the different maps was compared using statistical t test correlation. RESULTS: Normal gray to white matter contrast did not show a significant difference among the rCBV, MAX, and SUB maps. Based on statistical evaluation, the low-grade lesions did not differ significantly in the rCBV, MAX, and SUB maps. The group with high-grade lesions (12 patients) showed no significant difference in standardized rCBV, MAX, and SUB maps. CONCLUSION: Compared to rCBV maps, the simple MAX and SUB maps demonstrated good correlation in both high-grade and low-grade gliomas. This simpler approach could establish first-pass reconstruction in clinical settings because it reduces the need for time-consuming postprocessing.

Adult↗

PubMed1998

MRI assessment of cerebral blood volume in patients with brain infarcts.

MRI perfusion studies have focussed mainly on acute ischaemia and characterisation in ischaemia. Our purpose was to analyse regional brain haemodynamic information in acute, subacute, and chronic ischaemia. We performed 16 examinations of 11 patients on a 1.5 T MR images. Conventional and dynamic contrast-enhanced imaging were employed in all examinations. For the dynamic susceptibility sequences, a bolus (0.2 mmol/kg) of gadopentetate dimeglumine was injected. Reconstructed regional relative cerebral blood volume (rCBV) maps, bolus maps, and conventional images were analysed by consensus reading. In all examinations decreases in rCBV were observed in the lesions. The distribution of regional rCBV in lesions was heterogeneous. The rCBV of the periphery of the lesions was higher than that at their center. There was a correlation between the time since onset and abnormalities on the rCBV map and T2-weighted images (T2WI). In the early stage of acute stroke, the abnormalities tended to be larger on the rCBV than on T2WI. Many patterns of bolus passage were observed in ischaemic regions. rCBV maps provide additional haemodynamic information in patients with brain infarcts.

Adult↗

PubMed1998

Oxygen-induced MR signal changes in murine tumors.

Breathing of 100% oxygen was used to challenge vascular autoregulation in 14 mice with either osteosarcomas (n = 6) or mammary carcinomas (n = 8). Reproducible and statistically significant signal intensity changes of -29 +/- 6% to +35 +/- 3% were observed on heavily T2*-weighted images in the tumors during the oxygen challenge. No significant changes were observed in muscle. For the mammary carcinomas a higher percentage of tumor voxels showed significant signal-intensity decrease (31 +/- 8%) compared to the percentage of voxels showing a signal-intensity increase (22 +/- 3%). In contrast, for the osteosarcomas, a higher percentage of tumor voxels showed signal-intensity increase (52 +/- 9%) compared to the percentage of voxels showing signal-intensity decrease (27 +/- 9%). The regional distribution of these signal intensity changes did not correlate with the signal pattern on T1-, T2-,and T2*-weighted and Gd-DTPA enhanced images acquired without breathing 100% oxygen. Most likely, the signal intensity changes represented the inability of the tumor's neovascularization for autoregulation during the oxygen challenge, particularly in hypoxic regions. Although further investigation is needed, the findings that malignant tumor tissue showed signal intensity changes, whereas normal muscle tissue did not, suggests that this technique may prove useful in distinguishing benign from malignant tissue.

Adenocarcinoma↗

PubMed1998

Preoperative 3D-reconstructions of ultrafast-CT images for the planning of minimally invasive direct coronary artery bypass operation (MIDCAB).

BACKGROUND: The direct left internal mammary artery (LIMA) bypass to the left anterior descending (LAD) without the use of extracorporal circulation through a small anterolateral thoracotomy has become established among the minimally invasive techniques in cardiac surgery. Technical difficulties may occur in patients with an enlarged left ventricle and subsequent lateral positioning of the LAD, a small LAD, or a small LIMA. We used electron beam tomography (EBT) for preoperative visualization of the topographical structures to seek out patients with potential technical difficulties. METHODS: Eighteen patients, mean age 62 +/- 13 years, were entered in this study; in all cases the indication for revascularization was a significant stenosis of the LAD. Preoperatively an ECG-triggered EBT was performed. Following the image acquisition, a three-dimensional reconstruction of the data was performed. The LIMA, LAD, first diagonal branch, and chest wall were stained different colors for better visualization. Surgery was performed using a left anterolateral mini-thoracotomy and through this access, the LIMA was dissected and anastomosed using a stabilizer without the use of extracorporal circulation. RESULTS: In all but one of the 18 patients who had a preoperative EBT, the minimally invasive direct coronary artery bypass (MIDCAB) procedure was successfully performed using an anterolateral mini-thoracotomy. Based on the results of the EBT, the 5 centimeter incision was done parasternally in six patients, and more laterally (2-4 cm parasternally) in the other eleven cases. In 13 patients the access penetrated the fourth intercostal space; in four cases the fifth intercostal space was used. In one patient EBT revealed a very laterally positioned and diffusely arteriosclerotic LAD so the patient was operated using a median sternotomy, but without the use of extracorporal circulation. In all 18 patients the preoperatively acquired information of the anatomical topography was confirmed intraoperatively. One case without a preoperative EBT had to be converted to a conventional procedure due to a small, intramyocardial LAD and a very small LIMA. Postoperative angiography revealed patent LIMA grafts and uneventful anastomoses. CONCLUSIONS: For minimally invasive direct coronary artery bypass (MIDCAB) the topography of the LIMA, LAD and intercostal spaces is of major importance. Using the ECG-triggered EBT with subsequent three-dimensional reconstruction these relationships can be visualized. This enables an individual planning of the operation and a minimalization of the skin incision.

Aged↗

PubMed1997

Magnetic resonance imaging of the female pelvis. New circularly polarized body array coil versus standard body coil.

RATIONALE AND OBJECTIVES: The authors compare the value of a new circularly polarized body array coil (BAC) system with a standard body coil (BC) for high-resolution magnetic resonance imaging of the female pelvis. METHODS: Twenty patients with cervical cancer were examined with a BC and BAC. Imaging parameters were kept constant (sagittal T2-weighted turbo spin-echo: repetition time = 4000 mseconds; effective echo time = 99 mseconds; 160 x 160 mm field of view; 256 x 256 matrix; 0.63 x 0.63 mm pixel size; 4-mm slice thickness). Images were scored for lesion-to-organ delineation and overall image quality/ artifacts using a scale from 5 to 1 (excellent to poor). Signal-to-noise (S/N) ratios for different tissues (tumor, uterus, vagina, rectum, muscle, and fat) as well as contrast-to-noise (C/N) ratios between tumor and (1) uterus, (2) vagina, and (3) rectum were calculated. Magnetic resonance tumor staging was performed according to the International Federation of Gynecology and Obstetrics (FIGO) classification. RESULTS: Using the BAC, S/N and C/N ratios increased significantly compared with the BC (S/N: 2.7-3.4-fold increase for all organs evaluated, P < 0.001: C/N: tumor versus uterus 2.4-fold, P < 0.01; tumor versus vagina 6.1-fold, P < 0.001; tumor versus rectum 3.1-fold, P < 0.01). This resulted in an improved overall image quality (average ratings: BAC-4.3 points; BC-2.6 points; P < 0.001). Lesion-to-organ delineation (average ratings: BAC 4.3-4.1 points, BC 3.5-2.7 points for all organs evaluated; P < 0.001) was increased noticeably on BAC images. No significant difference was found for staging accuracy. CONCLUSIONS: Circularly polarized BAC provide superior S/N and C/N ratios and improve lesion conspicuity compared with standard BC.

Adult↗

PubMed1996

Echo-planar MR determination of relative cerebral blood volume in human brain tumors: T1 versus T2 weighting.

PURPOSE: Maps related to relative cerebral blood volume (rCBV) were generated with the use of the T1 effects produced by a low-dose bolus passage of gadopentetate dimeglumine. The T1 maps were evaluated in a tumor population and compared with rCBV maps obtained with T2-weighted measurements. METHODS: Imaging was performed in 19 patients with suspected intraaxial brain tumors. For the T1 rCBV maps, a low-dose bolus of contrast material was given during T1-weighted interleaved spin-echo echo-planar MR imaging. This was followed by a second injection during serial T2-weighted imaging for generation of the T2 rCBV maps. RESULTS: Among patients with low-grade lesions (n = 9), T1-based and T2-based rCBV maps showed comparably low rCBV in 7 subjects. In the other 2 patients, with confirmed tumor dedifferentiation, elevation of rCBV values was seen on maps obtained with both techniques. Among patients with high-grade tumors (n = 10), 4 had no evidence of recurrence and 6 did have tumor recurrence (confirmed by follow-up and positron emission tomography). In patients with the high-grade lesions exhibiting conventional contrast enhancement, lesions tended to have higher estimated values on T1 rCBV maps than on the T2 rCBV maps. CONCLUSION: Although the T1 rCBV maps showed less contrast as compared with the T2 rCBV maps, they provided diagnostic information that was comparable to the T2 rCBV maps in our series of 19 patients with primary brain tumors.

Adult↗

PubMed1990

The second riboflavin-binding myeloma IgG lambdaDOT. I. Biochemical and functional characterization.

A human monoclonal immunoglobulin, IgGDOT, with flavin-binding capacity has been obtained from an elderly woman with multiple myeloma who developed yellow skin and yellow hair. The case presented a remarkable similarity with that previously reported by Farhangi and Osserman [N. Engl. J. Med. 294, 177-183 (1976)]. Purified IgGDOT was bright yellow and the ligand was identified as riboflavin and its oxidation products by thin layer chromatography, proton nuclear magnetic resonance and mass spectroscopy. Competitive binding studies with different haptens demonstrated highest affinity for riboflavin, followed by flavin mononucleotide and flavin adenine dinucleotide; no significant binding was detected for several other non-flavin compounds tested. The hapten was associated with the protein in vivo, as well as with the purified antibody. Removal of the already bound riboflavin from the combining site was associated with irreversible denaturation of the monoclonal protein. By the fluorescence quenching technique it was determined that there were 0.68 available combining sites for riboflavin molecule in IgGDOT with a binding constant of 8.5 x 10(8)/M, while FabDOT presented 0.27 available combining sites with a binding constant of 5.1 x 10(8)/M. The fact that 1.2 and 0.81 mol riboflavin/mol protein were already bound to IgGDOT and FabDOT, respectively, is consistent with the usual hapten/antibody stoichiometry. The heavy chain subclass of IgGDOT was identified as gamma 2, as in the previously reported case of riboflavin-binding protein IgGGAR. However, the lambda chain subclass was different and no idiotype cross-reactivity was found.

Aged↗

PubMedDate not supplied

Regional relative blood volume MR maps of meningiomas before and after partial embolization.

PURPOSE: Our goal was to evaluate the role of relative blood volume (rBV) measurements in monitoring the embolization effect in meningiomas by using maps of susceptibility-weighted first pass MR data. METHOD: Eighteen examinations of nine patients before and following partial embolization were performed on a 1.5 T scanner. Embolization was achieved by injection of particles (45-150 microns). During dynamic imaging a bolus (0.2 mmol/kg) of gadopentetate dimeglumine was injected. RESULTS: The tumor rBV/gray matter rBV ratio was 3.11 +/- 1.40 for untreated tumors and 0.12 +/- 0.09 for successfully embolized tumors. The regional rBV in embolized meningiomas was significantly lower than that in untreated meningiomas (t test, p < 0.001). Vital tumor tissue showed positive enhancement in T1 and high rBV; nonvital tissue lacked T1 enhancement and bolus effect in the first pass, thus leading to low or missing rBV values. However, we also observed lack of bolus formation despite T1 enhancement (6/9 postembolization regions), possibly due to slow collateral flow. One of the patients treated with embolization bled during surgery. CONCLUSION: Maps of relative regional cerebral BV provide hemodynamic information in meningiomas and monitor the treatment effect of embolization in meningiomas more precisely than T1-weighted contrast-enhanced imaging.

Blood Loss, Surgical↗

PubMedDate not supplied

Xenon versus ceramics: a comparison of two CT X-ray detector systems.

PURPOSE: The purpose of this work was to compare image quality in phantom and patient CT scans acquired by xenon and ceramic CT detector systems. METHOD: High and low contrast resolution and image noise were determined with a standard CT phantom for both detector systems. In patient CT images, the effect on image noise was measured in anatomical regions of interest in the head, lumbar spine, chest, and abdomen. RESULTS: In phantom studies, image noise was significantly lower using ceramic versus xenon detectors. Also, in images of the head and lumbar spine, the signal-to-noise ratio was significantly higher with ceramic than with xenon detectors. In chest scans, ceramic significantly reduced beam-hardening artifacts caused by the thoracic spine. However, in abdominal images, the signal-to-noise ratio was not significantly different between ceramic and xenon detector systems. CONCLUSION: For reduced image noise in CT images of the head, lumbar spine, and chest and high resolution CT, ceramic detector systems appear to be superior to xenon detector systems.

Artifacts↗