Multislice Spiral Computed Tomography Imaging Research Articles

Application value of multislice spiral computed tomography angiography in the evaluation of renal artery variation in living donor kidney transplantation.

This study aims to investigate the accuracy and value of multislice spiral computed tomography (MSCT) angiography in the evaluation of renal artery variation in living donor kidney transplantation. Two hundred seventy-three kidney transplantation donors underwent preoperative MSCT scanning. Two doctors determined the running direction and variation of the renal artery through joint analysis of the preoperative original MSCT image and the recombination image using the blind reading method, compared the imaging results with the intraoperative results, and evaluated the accuracy and application value of MSCT angiography in the evaluation of renal artery variation in living donor kidney transplantation. CT angiography (CTA) can better show the renal artery and its variation. A total of 52 accessory renal arteries were found in the 273 kidney transplant operations, whereas 55 accessory renal arteries were found in preoperative MSCT. Four accessory renal arteries indicated in the MSCT were not found during the operation, and one accessory renal artery found during the operation was not indicated in the preoperative MSCT. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of MSCT in the diagnosis of accessory renal arteries were 98.1, 98.2, 92.7, 99.5, and 98.2%, respectively. MSCT angiography can sensitively and accurately show the renal artery and its variation in living donor kidney transplantation, and has important clinical value for the formulation of the operative scheme before the transplantation.

Bioceramic-collagen scaffolds loaded with human adipose-tissue derived stem cells for bone tissue engineering

The combination of bioceramics and stem cells has attracted the interest of research community for bone tissue engineering applications. In the present study, a combination of Bio-Oss(®) and type 1 collagen gel as scaffold were loaded with human adipose-tissue derived mesenchymal stem cells (AT-MSCs) after isolation and characterization, and the capacity of them for bone regeneration was investigated in rat critical size defects using digital mammography, multi-slice spiral computed tomography imaging and histological analysis. 8weeks after implantation, no mortality or sign of inflammation was observed in the site of defect. According to the results of imaging analysis, a higher level of bone regeneration was observed in the rats receiving Bio-Oss(®)-Gel compared to untreated group. In addition, MSC-seeded Bio-Oss-Gel induced the highest bone reconstruction among all groups. Histological staining confirmed these findings and impressive osseointegration was observed in MSC-seeded Bio-Oss-Gel compared with Bio-Oss-Gel. On the whole, it was demonstrated that combination of AT-MSCs, Bio-Oss and Gel synergistically enhanced bone regeneration and reconstruction and also could serve as an appropriate structure to bone regenerative medicine and tissue engineering application.

Enhanced reconstruction of rat calvarial defects achieved by plasma-treated electrospun scaffolds and induced pluripotent stem cells

Tissue engineering with a combination of stem cells and nanofibrous scaffolds has attracted interest with regard to bone regeneration applications. In the present study, human induced pluripotent stem cells (iPSCs) were cultured on polymeric nanofibrous polyethersulfone (PES) with and without plasma treatment. The capacity of PES and plasma-treated PES (Plasma-PES) scaffolds to support the proliferation and osteogenic differentiation of iPSCs was investigated by MTT assay and for common osteogenic markers such as alkaline phosphatase activity, calcium mineral deposition and bone-related genes. Plasma-PES scaffolds with or without iPSCs were subsequently used to evaluate bone regeneration of critical-size defects in the rat by digital mammography, multislice spiral-computed tomography imaging and histological analysis. The results of in vitro analysis showed that plasma treatment significantly enhanced iPSC proliferation and osteogenesis. After 8 weeks of iPSC-loaded Plasma-PES implantation, no mortality or complication was observed in animals or at the site of surgery. Imaging analysis revealed more extensive bone reconstruction in rats receiving nanofibers compared with untreated control groups. Moreover, Plasma-PES seeded with iPSCs induced the highest regeneration of bone defects among all groups. These findings were confirmed by histological staining. Affective osseointegration was observed in implanted scaffolds. Thus, plasma-treated nanofibrous scaffolds are suitable tissue-engineered matrices for supporting the proliferation and osteogenic differentiation of iPSCs and might also be appropriate for the reconstruction of bone defects.

Clinical application of multi-slice spiral computed tomography imaging with post-processing technology in lamina papyracea fracture

This paper aimed at evaluating clinical value of multi-slice spiral computed tomography (MSCT) with post-processing technology in diagnosis for lamina papyracea fracture (LPF). Volume scanning with MSCT was performed for 97 cases with LPF followed by post-processing with axial highresolution reconstruction, coronal multi-planar reformation ( CMPR), coronal maximum intensity projection (CMIP) and volume rendering (VR). Obtained images in the patients with fracture were compared with their primary axial scanning, including 42 with line-type fracture without obvious dislocation, 48 cases with depression fracture with dislocation, and seven cases with non-depression fracture showing dislocation.Twelve of them displayed two margins sign, seven diagnosed by CMPR and CMIP images and five by VR combined with CMPR. Thirty-nine cases complicated with swelling of the intraocular muscle, 25 with intraorbital fat hernia into the ethmoid sinus, 66 cases with intraorbital air and liquid deposited at the ethmoid sinus, and 15 with retro-bulbar hemorrhage. MSCT with post-processing technology can accurately display direct and indirect signs of LPF which can be further divided into varied types, and is the most effective method in clinical diagnosis. Key words: Orbital fractures; Tomography spiral computed

Measuring mesiodistal width of impacted maxillary canines

Precise, three-dimensional localization of impacted maxillary canines is central to their clinical management. Predicting precisely the crown's mesiodistal width is paramount in planning orthodontic treatment. The aim of this study was to verify the exact mesiodistal width of impacted canines via MSCT (multislice spiral computed tomography) examinations. 3D MSCT images from 17 patients with a total of 24 impacted maxillary canines were taken to obtain the largest mesiodistal diameter using mesial and distal contact points. All existing maxillary canines were included in this study. Mesiodistal tooth width was also determined using callipers on a plaster model after canine eruption. Each measurement was taken twice by 3 observers after a 10-day interval. Statistical analysis entailed calculating and comparing the systematic error, intrarater and interrater standard deviations (Deming regression and ANOVA with random effects). Comparison of the different methods revealed good agreement between the pre-eruption and post-eruption values regarding the canine's mesiodistal width. Total standard deviation was 0.16 mm for values obtained from MSCT measurements and 0.12 mm for those taken with callipers. For both methods intrarater measurement error differed by a factor of 2 (repeatability; model versus MSCT: 0.07 mm versus 0.12 mm), while interrater deviation did not differ significantly (reproducibility; model versus MSCT: 0.10 mm versus 0.10 mm). The reproducibility of our measurements whether taken on the model or with CT was below biological variability. The volumetric data from an MSCT system gives highly accurate information on the mesiodistal width of displaced canines.

Automatic Transfer Function Specification for Visual Emphasis of Coronary Artery Plaque

Abstract Cardiovascular imaging with current multislice spiral computed tomography (MSCT) technology enables a non‐invasive evaluation of the coronary arteries. Contrast‐enhanced MSCT angiography with high spatial resolution allows for a segmentation of the coronary artery tree. We present an automatically adapted transfer function (TF) specification to highlight pathologic changes of the vessel wall based on the segmentation result of the coronary artery tree. The TFs are combined with common visualization techniques, such as multiplanar reformation and direct volume rendering for the evaluation of coronary arteries in MSCT image data. The presented TF‐based mapping of CT values in Hounsfield Units (HU) to color and opacity leads to a different color coding for different plaque types. To account for varying HU values of the vessel lumen caused by the contrast medium, the TFs are adapted to each dataset by local histogram analysis. We describe an informal evaluation with three board‐certified radiologists which indicates that the represented visualizations guide the user's attention to pathologic changes of the vessel wall as well as provide an overview about spatial variations.

Value of multi-slice spiral computed tomography in the diagnosis of gastrointestinal cancer.

Objective To evaluate multi-slice spiral computed tomography(MSCT)in the diagnosis and preoperative staging of gastrointestinal cancer.Methods (1)Three hundred and thirty-two gastric cancer patients underwent preoperative MSCT examination.The staging of gastric cancer by MSCT was compared with histological examination.(2)Seventy-three small intestinal cancer patients underwent preoperative MSCT,and 70 healthy adults were selected as normal contr01.The MSCT images of small intestinal lymphoma and small intestinal cancer were compared with those of normal small intestine.(3)Two hundred and twenty-eight colorectal cancer patients underwent preoperative MSCT,and the features of the MSCT images of colorectal cancer were analyzed by chi-square test.Results (1)The overall accuracy of MSCT in the assessment of gastric wall invasion,lymph node metastasis and distal metastasis were 78.2%(244/312),67.3%(210/312)and 93.8%(30/32),respectively.More information such as the location of lesions and the vessels around the stomach couldbe provided by MSCT image.(2)Abdominal masses,diffuse thickening of intestinal wall and intestinal obstruction were the main features of small intestinal cancer,while mesenterie and retroperitoneal lymph nodes metastases were rarely detected.The presentation of small intestinal lymphoma detected by MSCT were completely the opposite.(3)Signs such ascoarse surfaceandheterogeneous enhancementwere important to the diagnosis of colorectal cancer.The measurement of the MSCT value is helpful in the differential diagnosis of colorectal cancer and colonic inflammation.Conclusions MSCT can provide correct imaging information on the diagnosis and preoperative staging of gastrointestinal cancer.The combination of MSCT and endoscopy can improve the accuracy of diagnosis. Key words: Gastric neoplasms; Colonic neoplasms; Multi-slice spiral computed tomography; Diagnosis

Perfusion weighted color maps for enhanced visualization of myocardial infarction by MSCT: preliminary experience

The reliable detection of myocardial perfusion defects and myocardial infarction (MI) is of great interest in the comprehensive workup of coronary artery disease. The aim of this study was to optimize the ability of contrast-enhanced cardiac multislice spiral computed tomography (MSCT) for detecting hypoperfused myocardium as surrogate marker of MI using a newly developed post-processing technique. First a model-based software tool for semi-automated detection of the long axis of the left ventricle and assignment of left-ventricular segments was developed using a region growing algorithm and a point distribution model. To visualize changes of the myocardial contrast enhancement pattern color coding was performed after spreading of the attenuation values. 15 patients (12 men, mean age 57 +/- 15 years) with a history of MI underwent cardiac MSCT (16 x 0.75 mm, 120 kV, 550 mA s(eff.), 100 ml Iopromide) and contrast enhanced delayed enhanced magnetic resonance imaging (DE-MRI) after administration of 0.2 mmol Gd-DTPA/kg/bodyweight as reference standard. Presence of infarction was assessed from MSCT, post-processed MSCT images and DE-MRI using a 17-segment model of the left ventricle. On DE-MRI MI was present in 78/255 myocardial segments. From conventional MSCT images MI was detected in 63/255 segments (5 false positive; sensitivity 74.4%; specificity: 97.1%), while on post-processed images MI was assigned to 74/255 segments (6 false positive; sensitivity 87.2%; specificity: 96.6%). Agreement between DE-MRI and conventional MSCT images for detecting MI was kappa = 0.756. Using post-processed images agreement improved to kappa = 0.850. MSCT detection of hypoperfused myocardium as surrogate for MI can be improved using dedicated post processing algorithms.

Multislice Spiral Computed Tomography Imaging in Congenital Inner Ear Malformations

The purpose of this study is to evaluate the usefulness of multislice spiral computed tomography (CT) in the diagnosis of congenital inner ear malformations. Forty-four patients with sensorineural hearing loss were examined on a Somatom Sensation 16 (Siemens) CT scanner. The 3-dimensional reconstructions and multiplanar reformation (MPR) were performed using the volume-rendering technique (VRT) on the workstation. Of the 44 patients examined for this study, 25 patients were found to be normal and 19 patients (36 ears) were diagnosed with congenital inner ear malformations. Of the malformations, the axial, MPR, and VRT images can all display the site and degree in 33 of the ears. Volume-rendering technique images were superior to the axial images in displaying the malformations in 3 ears with small lateral semicircular canal malformations. The common malformations were Michel deformity (1 ear), common cavity deformity (3 ears), incomplete partition I (3 ears), incomplete partition II (Mondini deformity) (5 ears), vestibular and semicircular canal malformations (14 ears), enlarged vestibular aqueduct (16 ears, 6 of which had other malformations), and internal auditory canal malformation (8 ears, all accompanied by other malformations). Multislice spiral CT allows a comprehensively assessment of various congenital inner ear malformations through high-quality MPR and VRT reconstructions. Volume-rendering technique images can display the site and degree of the malformation 3-dimensionally and intuitionisticly. This is very useful to the cochlear implantation.

Noninvasive evaluation of coronary artery stenosis by multi-slice spiral CT with standardized reconstruction images

目的 通过建立统一的重组图像体位研究多层螺旋CT(MSCT)诊断冠状动脉狭窄的准确性.方法 对55例临床可疑冠心病患者行16层螺旋CT心电门控增强扫描.用舒张期增强扫描图像行统一体位的最大密度投影(MIP)及容积显示技术(VRT)重组,分析应用CT血管成像(CTA)7个MIP重组体位和9个VRT重组体位评价冠状动脉狭窄≥50%的情况,将结果与常规X线冠状动脉造影作对照.结果 共分析55例患者的220个血管分支,常规X线冠状动脉造影发现62个血管分支狭窄≥50%,综合7个MIP重组体位和9个VRT重组体位,CTA发现58个血管分支狭窄≥50%(左主干5个,前降支21个,回旋支14个,右冠状动脉18个).CTA诊断冠状动脉狭窄≥50%的敏感性为94%(58/62),特异性为92%(146/158),准确率为93%(204/220),阳性预测值83%(58/70),阴性预测值97%(146/150).结论 MSCT诊断冠状动脉狭窄有较高的敏感性和特异性;建立统一的成像体位有利于CTA与常规X线冠状动脉造影结果对照。

Detection of myocardial bridge and evaluation of its anatomical properties by coronary multislice spiral computed tomography

Background Myocardial bridge (MB) is a common anatomical condition, under which a part of the coronary artery running in the epicardial adipose tissue is covered with myocardial tissue. It regulates atherosclerosis development and sometimes evokes coronary heart disease through haemodynamic alterations. We attempted to efficiently detect MB and evaluate the anatomical properties of MB by coronary multislice spiral computed tomography (MSCT). Methods Sixteen-row MSCT was conducted on 148 patients with coronary heart disease. MSCT images were reconstructed and reformed with transverse scans, curved planar reformat, and three-dimensional, volume-rendered images. The MB, over 1.0 mm in thickness, was identified by the presence of the “step-down and step-up” appearance. After “trial and error” essays, we could consistently examine the frequency of MB and evaluate the anatomical properties of MB, especially its thickness, together with coronary wall lesions. Results Twenty-three patients (15.8%) had MB over 1.0 mm in thickness: 21 MBs (87.5%) were located in the left anterior descending artery with a mean thickness and length of 1.8±0.7 and 20.0±8.6 mm. Moreover, although the tunneled segment beneath MB was always free of coronary wall lesions, 79.2% (19/24) of the segments proximal to MB demonstrated coronary wall lesions. Of special significance were three symptomatic MB patients without any atherosclerotic lesion throughout all the coronary arteries. Conclusion Coronary MSCT is a new imaging technique that provides a noninvasive diagnostic tool for MB and yields much better results of MB detection than previous imaging methods. Myocardial bridge (MB) is a common anatomical condition, under which a part of the coronary artery running in the epicardial adipose tissue is covered with myocardial tissue. It regulates atherosclerosis development and sometimes evokes coronary heart disease through haemodynamic alterations. We attempted to efficiently detect MB and evaluate the anatomical properties of MB by coronary multislice spiral computed tomography (MSCT). Sixteen-row MSCT was conducted on 148 patients with coronary heart disease. MSCT images were reconstructed and reformed with transverse scans, curved planar reformat, and three-dimensional, volume-rendered images. The MB, over 1.0 mm in thickness, was identified by the presence of the “step-down and step-up” appearance. After “trial and error” essays, we could consistently examine the frequency of MB and evaluate the anatomical properties of MB, especially its thickness, together with coronary wall lesions. Twenty-three patients (15.8%) had MB over 1.0 mm in thickness: 21 MBs (87.5%) were located in the left anterior descending artery with a mean thickness and length of 1.8±0.7 and 20.0±8.6 mm. Moreover, although the tunneled segment beneath MB was always free of coronary wall lesions, 79.2% (19/24) of the segments proximal to MB demonstrated coronary wall lesions. Of special significance were three symptomatic MB patients without any atherosclerotic lesion throughout all the coronary arteries. Coronary MSCT is a new imaging technique that provides a noninvasive diagnostic tool for MB and yields much better results of MB detection than previous imaging methods.

Late-phase MSCT in the different stages of myocardial infarction: animal experiments

The purpose of this study was to intraindividually evaluate myocardial late enhancement on multislice spiral computed tomography (MSCT) for the assessment of the different stages of myocardial infarction (MI) in comparison with magnetic resonance (MR) imaging. Reperfused MI was successfully induced in seven pigs. Delayed enhancement MR imaging and late-phase MSCT were performed on day 0 as well as 7, 28 and 90 days after the procedure. The pigs were sacrificed, and 2,3,5-triphenyltetrazolin-chloride (TTC) staining was acquired. MI size was compared between the different imaging techniques and over time applying Bland-Altman plots and multivariate analysis with repeated measures. On day 0 the mean MI size was 23.7 +/- 11.8% of the left ventricular area on MSCT and 24.5 +/- 10.6% on MR imaging. On day 90 infarct sizes decreased significantly to 16.9 +/- 8.4% and 18.9 +/- 8.0%, respectively (P = 0.0019). On TTC staining the size of MI was 16.8 +/- 8.2%. Bland-Altman plots showed a good agreement between MSCT and MR imaging with mean deviations ranging from -3.4% to -1.9%. No significant difference between MSCT and MR imaging was found. Myocardial late enhancement on MSCT correlates well with delayed enhancement MR imaging during the different stages of MI and allows for reliable assessment of reperfused MI during acute, subacute and chronic stages.

Detection of myocardial bridge and evaluation of its anatomical properties by coronary multislice spiral computed tomography

Background Myocardial bridge (MB) is a common anatomical condition, under which a part of the coronary artery running in the epicardial adipose tissue, is covered with myocardial tissue. It regulates atherosclerosis development and sometimes evokes coronary heart disease through haemodynamic alterations. We attempted to efficiently detect MB and evaluate the anatomical properties of MB by coronary multislice spiral computed tomography (MSCT). Methods Sixteen-row MSCT was conducted on 148 patients with coronary heart disease. MSCT images were reconstructed and reformed with transverse scans, curved planar reformat and three-dimensional volume-rendered images. The MB, over 1.0 mm in thickness, was identified by the presence of the “step-down and step-up” appearance. After “trial and error” essays, we could consistently examine the frequency of MB and evaluate the anatomical properties of MB, especially its thickness, together with coronary wall lesions. Results Twenty-three patients (15.8%) had MB over 1.0 mm in thickness: 21 MBs (87.5%) were located in the left anterior descending artery with a mean thickness and length of 1.8 ± 0.7 and 20.0 ± 8.6 mm. Moreover, although the tunneled segment beneath MB was always free of coronary wall lesions, 79.2% (19/24) of the segments proximal to MB demonstrated coronary wall lesions. Of special significance were three symptomatic MB patients without any atherosclerotic lesion throughout all the coronary arteries. Conclusion Coronary MSCT is a new imaging technique that provides a non-invasive diagnostic tool for MB and yields much better results of MB detection than previous imaging methods.

Assessment of bone segmentation quality of cone-beam CT versus multislice spiral CT: a pilot study

The objective of this study was to quantitatively assess the quality of jawbone models generated from cone beam computed tomography (CBCT) by comparison with similar models obtained from multislice spiral computed tomography (MSCT). Three case studies were performed involving images of anthropomorphic head phantoms and real patients acquired with 3 CBCT (NewTom 9000 DVT, Accuitomo 3D, and i-CAT) and 2 MSCT scanners (Somatom VolumeZoom and Lightspeed). Bone was segmented from the CBCT and MSCT images using global thresholding. CBCT vs MSCT segmentation differences were assessed by comparing bone thickness measurements at anatomically corresponding sites, identified automatically by CBCT to MSCT image registration. There was a statistically significant difference between the MSCT and CBCT segmented bone thicknesses, varying from 0.05 +/- 0.47 mm (i-CAT) up to 1.2 +/- 1.00 mm (3D Accuitomo, posterior maxilla). An automated, reproducible, and observer-independent method has been developed to assess the quality of CBCT bone models using MSCT as a clinically established method of reference. Our validation method is generally applicable in cases where no geometric ground-truth is available.

Image quality and diagnostic accuracy of 16-slice multidetector computed tomography for the detection of coronary artery disease in obese patients

Cardiac multislice spiral computed tomography (MSCT) scanners permit visualization of the coronary arteries with an overall good sensitivity (sens) and specificity (spec). However, in obese patients (pts), who are at higher risk to develop coronary artery disease (CAD), image quality of MSCT is supposed to be limited. At present, there are no data whether the accuracy of MSCT depends on the body mass index (BMI). Thus, we compared the catheter-controlled MSCT results from normal weight and obese pts in a cohort of 117 pts with regard to sens, spec, positive predictive value (PPV), negative predictive value (NPV) and image quality. In all, 21 normal weight pts (group I: BMI<25, 64.6+/-11.1 years, number of risk factors 2.1+/-1.1), 60 pts with mild overweight (group II: BMI 25-30, 64.6+/-8.9 years, number of risk factors 3.4+/-1.0) and 36 obese pts (group III: BMI >30, 63.0+/-8.5 years, number of risk factors 3.4+/-0.9) were examined by MSCT (Sensation 16 Speed 4 D((R)), Siemens, Germany, gantry rotation time 375 ms) and invasive coronary angiography. MSCT results were compared blinded to the results of the coronary angiography with regard to the presence or absence of a significant stenosis (>50%) in a modified AHA 13 segment (sgt) model. Image quality was assessed on a qualitative scale between 1 (very good) and 5 (insufficient image quality) for each sgt. Sens, spec, PPV and NPV were statistically not different in all three groups (I: 0.88/0.97/0.91/0.96, II: 0.83/0.97/0.88/0.95, III: 0.87/0.99/0.96/0.96). 3 pts (group I 1, group II 2) had to be excluded from analysis due to technical problems. Group I had significantly less risk factors (P < 0.001) and image quality was significantly better than in group II and III (P < 0.05). Group II and III did not differ with regard to risk factors or image quality. Overweight and obesity have an impact on MSCT image quality but did not hamper the diagnostic accuracy. Thus, MSCT is a noninvasive method to detect or rule out CAD also in pts with higher BMI. These retrospective data have to be confirmed in larger prospective trials.

Image Quality and Diagnostic Accuracy of 16-Slice Multidetector Spiral Computed Tomography for the Detection of Coronary Artery Disease in Elderly Patients

To determine the image quality and diagnostic accuracy of cardiac multislice spiral computed tomography (MSCT) in elderly patients (>65 years old) in comparison to younger patients, this retrospective analysis was performed. The catheter-controlled MSCT results from patients older than 65 years of age were compared with the results of younger patients in a cohort of 117 patients with regard to sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and image quality. Fifty-three patients were older than 65 years of age (group 1: 31 men, age range: 72.2 +/- 4.1 years, number of risk factors: 2.6 +/- 1.3, Agatston score: 866 +/- 1090) and 64 were younger (group 2: 45 men, age range: 57.4 +/- 6.1 years, number of risk factors: 2.6 +/- 1.0, Agatston score: 765 +/- 1013). All patients were examined by MSCT (Sensation 16 Speed 4 D; Siemens, Forchheim, Germany, with a gantry rotation time of 375 milliseconds) and invasive coronary angiography. The MSCT results were compared blinded with the results of the coronary angiography with regard to the presence or absence of significant stenosis (>50%) in a 13-segment model. Image quality was assessed on a qualitative scale between 1 (very good) and 5 (insufficient image quality) for each segment. Sensitivity, specificity, PPV, and NPP were not different statistically in both groups (group 1: 0.80/0.96/0.89/0.93 and group 2: 0.89/0.98/0.93/0.97). Three patients (all <65 years old) had to be excluded from analysis because of technical problems. Image quality was significantly better in group 2. Gender, body mass index, number of risk factors, and mean heart rate were not significantly different in either group. Age has an impact on MSCT image quality but did not hamper diagnostic accuracy. Thus, MSCT is a noninvasive method to detect or rule out coronary artery disease independently of age. These retrospective data have to be confirmed in larger prospective trials.

Multislice Spiral Computed Tomography of the Heart: Technique, Current Applications, and Perspective

Multislice spiral computed tomography (MSCT) is a rapidly evolving, noninvasive technique for cardiac imaging. Knowledge of the principle of electrocardiogram-gated MSCT and its limitations in clinical routine are needed to optimize image quality. Therefore, the basic technical principle including essentials of image postprocessing is described. Cardiac MSCT imaging was initially focused on coronary calcium scoring, MSCT coronary angiography, and analysis of left ventricular function. Recent studies also evaluated the ability of cardiac MSCT to visualize myocardial infarction and assess valvular morphology. In combination with experimental approaches toward the assessment of aortic valve function and myocardial viability, cardiac MSCT holds the potential for a comprehensive examination of the heart using one single examination technique.

Quantitative and Qualitative Assessment of Left Ventricular Volume with Ecg-Gated Multislice Spiral Ct: Value of Different Image Reconstruction Algorithms in Comparison to MRI

To assess the value of different image reconstruction algorithms for assessment of the left ventricular function using retrospectively ECG-gated multislice spiral computed tomography (MSCT) of the heart. MSCT and cine magnetic resonance (MR) imaging of the heart were performed in 15 patients. For MSCT, standard and multisegmental image reconstruction with improved temporal resolution were used. Standardized multiplanar reformats in the short axis and long axis views were reconstructed from MSCT data. End-systolic (ESV) and end-diastolic volume (EDV), stroke volume (SV), ejection fraction (EF) and myocardial mass (MM) were calculated. Left ventricular wall motion was assessed qualitatively. MSCT was in acceptable agreement with MR imaging for quantification of the ventricular function. According to the Bland-Altman approach the mean differences for the left ventricular volumes (ESV, EDV, SV) ranged from -9.6 ml to 3.1 ml with standard image reconstruction and from -0.6 ml to 1.9 ml utilizing multisegmental image reconstruction with limits of agreement ranging from -26.6 ml to 12.5 ml and -15.6 ml to 15.0 ml, respectively. Applying the multisegmental image reconstruction algorithm, a significantly improved agreement with the MR data was found for EDV, SV and EF. For wall motion analysis, standard image reconstruction showed a significant difference to MR imaging with a correspondence in 83.75% of the 240 assessed segments, while multisegmental image reconstruction agreed with MR imaging in 92.5% of the segments. Multisegmental image reconstruction improves the quantitative assessment of left ventricular function when compared to standard image reconstruction. Multisegmental image reconstruction allows qualitative wall motion analysis.

The effect of pitch in multislice spiral/helical CT.

The purpose of this study is to understand the effect of pitch on raw data interpolation in multislice spiral/helical computed tomography (CT) and provide guidelines for scanner design and protocol optimization. Multislice spiral CT is mainly characterized by the three parameters: the number of detector arrays, the detector collimation, and the table increment per x-ray source rotation. The pitch in multislice spiral CT is defined as the ratio of the table increment over the detector collimation in this study. In parallel to the current framework for studying longitudinal image resolution, the central fan-beam rays of direct and opposite directions are considered, assuming a narrow cone-beam angle. Generally speaking, sampling in the Radon domain by the direct and opposite central rays is nonuniform along the longitudinal axis. Using a recently developed methodology for quantifying the sensitivity of signal reconstruction from nonuniformly sampled finite points, the effect of pitch on raw data interpolation is analyzed in multislice spiral CT. Unlike single-slice spiral CT, in which image quality decreases monotonically as the pitch increases, the sensitivity of raw data interpolation in multislice spiral CT increases in an alternating way as the pitch increases, suggesting that image quality does not decrease monotonically in this case. The most favorable pitch can be found from the sensitivity-pitch plot for any given set of multislice spiral CT parameters. An example for four-slice spiral CT is provided. The study on the effect of pitch using the sensitivity analysis approach reveals the fundamental characteristics of raw data interpolation in multislice spiral CT, and gives insights into interaction between pitch and image quality. These results may be valuable for design of multislice spiral CT scanners and imaging protocol optimization in clinical applications.