Coronal multiplanar reconstruction view from whole lung thin-section CT by multidetector-row CT: determination of malignant or benign lesions and differential diagnosis in 68 cases of solitary pulmonary nodule

PURPOSE: The purpose of this study was to evaluate the usefulness of the coronal multiplanar reconstruction (MPR) view in comparison with transverse helical thin-section CT for both the determination of malignant or benign lesions and the differential diagnosis of solitary pulmonary nodules. MATERIALS AND METHODS: Sixty-eight cases of pathologically proved solitary pulmonary nodule less than 3 cm in diameter were enrolled in this study. For the routine study, transverse helical thin-section CT (1.25 mm collimation, FOV 20 cm) covering the areas with solitary pulmonary nodules as well as whole lung helical thin-section CT (2.5 mm collimation, 1.25 mm reconstruction interval, FOV 34.5 cm, pitch 6:1, high-spatial frequency algorithm) were scanned with a multidetector-row CT (MDCT) scanner. From the whole lung thin-section CT data, coronal MPR views (2.5 mm slice thickness) were reconstructed on a workstation. ROC analysis was used for an observer performance study, in which three observers indicated their confidence level for the determination of malignant or benign lesion for the nodules by means of transverse thin-section CT and coronal MPR. In addition, the observers recorded appropriate disease entities as the final diagnosis of each case. Accuracies of the final diagnosis based on the two sets of images were compared with McNemer' s test. RESULTS: In terms of the determination of malignant or benign lesion, there was no significant difference between the two sets of images (coronal MPR and transverse thin-section CT; mean Az=0.853 and 0.854, respectively). In addition, accuracy of the final diagnosis based on coronal MPR views (74%) was almost equal to that based on transverse thin-section CT (71%) (p=0.3). CONCLUSIONS: The diagnostic efficacy of the coronal MPR view is comparable to that of transverse thin-section CT for the evaluation of solitary pulmonary nodules.     

Comparison of quality of multiplanar reconstructions and direct coronal multidetector CT scans of the lung

OBJECTIVE: The purpose of this study was to compare the quality of coronal multiplanar reconstructions with the quality of direct coronal thin-section multidetector CT (MDCT) scans. MATERIALS AND METHODS: Axial multidetector CT (MDCT) scans were obtained through the entire lung in 10 normal autopsy lung specimens using an MDCT scanner. Four protocols were used: 0.5-mm collimation with a 0.5-mm reconstruction interval; 0.5-mm collimation with a 0.3-mm reconstruction interval; 1-mm collimation with a 0.5-mm reconstruction interval; and 2-mm collimation with a 1-mm reconstruction interval. Multiplanar reconstruction images with 0.5-mm slice thickness were obtained from the four types of data sets. Direct coronal thin-section CT of the same 10 autopsy lung specimens was performed using 0.5-mm scan collimation, a 0.3-mm reconstruction interval, a 25.6-cm field of view, and a 512 x 512 matrix. Two independent observers compared the image quality of each of the four coronal multiplanar reconstruction sets with that of direct coronal thin-section CT scans. The observers analyzed visualization of anatomic features and artifacts. RESULTS: The total image quality of the multiplanar reconstructions obtained from 0.5-mm collimation data with or without 0.3-mm overlapping reconstruction was equal to that of direct coronal thin-section CT scans in all 20 interpretations. The image quality of multiplanar reconstruction images from 0.5-mm collimation data either with or without overlapping reconstruction was superior to multiplanar reconstruction images obtained from 1- or 2-mm collimation scans (p < 0.01, Fisher's exact test). Stairstep artifacts in multiplanar reconstructions using 0.5-mm collimation without overlapping reconstruction were equal to those with overlapping reconstruction and were fewer than those on 1- or 2-mm collimation (p < 0.01, Mann-Whitney U test). CONCLUSION: The image quality of coronal multiplanar reconstructions from isotropic voxel data obtained using 0.5-mm collimation, with or without overlapping reconstruction, is similar to that of direct coronal thin-section CT scans.     

Thin-section axial multidetector computed tomography and multiplanar reformatted imaging of children with suspected foreign-body aspiration: Is virtual bronchoscopy overemphasized?

PURPOSE: To determine the added value of multidetector computed tomography (MDCT)-assisted virtual bronchoscopy (VB) to axial MDCT and multiplanar reformatted (MPR) imaging with respect to conventional bronchoscopy in the evaluation of children with suspected foreign-body aspiration (FBA). MATERIAL AND METHODS: Twenty-one consecutive children (14 male, seven female, age 8 months-7 years, mean age 3.5 years) presenting with the suspicion of FBA were examined with 16-slice MDCT using 100-120 kV, 30-50 mA, 1-mm section thickness, 1.2 pitch ratio, and 0.6-1.0-mm reconstruction interval. Before CT examinations, chest radiographies were also obtained in all cases. VB and MPR imaging were carried out after MDCT examinations. RESULTS: Nine foreign bodies were identified by gold-standard conventional bronchoscopy. VB, thin-section axial MDCT, and MPR images identified eight of nine foreign bodies. CT scans with MPR images and VB did not reveal a chronic foreign body; and, in one patient, endobronchial mucous was diagnosed as the foreign body. The sensitivity, specificity, and accuracy of thin-section axial MDCT and MPR images alone in the diagnosis of FBA were 88.9%, 91.7%, and 90.5%, respectively. Results were the same as those obtained when VB was also included. CONCLUSION: MDCT with VB and axial/MPR images provide equally valuable information in children with suspected foreign-body aspiration and prevent unnecessary conventional bronchoscopic examinations. However, VB increases total examination time and cost, and it does not provide additional information over MPR images in the evaluation of foreign-body aspiration.     

Isotropic chest CT examination: diagnostic quality of reformats

AIM: To evaluate the image quality of axial and coronal reformats obtained from isotropic resolution 40-channel chest computed tomography (CT) examinations. METHODS AND MATERIALS: Thirty consecutive patients with intravenous contrast-enhanced chest CT examinations using a 40-channel CT machine were enrolled for the study. The raw data were reconstructed into two sets of source axial images: 0.9 mm section width and 0.45 mm reconstruction interval (isotropic resolution) and 4mm section width with 3 mm reconstruction interval (anisotropic resolution; group A). The isotropic data set was reformatted into axial and coronal stacks (groups B and C, respectively) with 4 mm section width and 3 mm interval. Three independent readers evaluated stacks A to C using a three-point scale for resolution of right lower lobe segmental bronchi, edge sharpness of major and minor fissures, respiratory motion artefact, reconstruction artefact, noise and overall image quality. RESULTS: The sharpness of fissures scored significantly higher with the coronal reformats (group C) compared with the axial image sets (groups A and B) (p<0.01). Noise in group A scored significantly lower than groups B or C (p<0.01). For other parameters there was no statistical difference between the groups. There was substantial or excellent agreement between the reviewers. CONCLUSION: Isotropic imaging of the chest allows creation of reformats with similar image quality as similar thickness axial source images. These reformats are probably of sufficient quality to form the basis of clinical interpretation.     

Assessment of hilar and extrahepatic bile duct cancer using multidetector CT: value of adding multiplanar reformations to standard axial images

To retrospectively assess the value of multiplanar reformations (MPRs) compared with standard axial images in the assessment of hilar and extrahepatic bile duct cancer. Forty-eight patients with confirmed bile duct cancer were included as preoperative work-ups; all of these patients underwent contrast-enhanced multidetector CT consisting of axial and MPR images. Two radiologists independently assessed the axial images alone and the combined axial and MPR images in the coronal and sagittal planes for the presence of tumor, its extent, vascular involvement, and resectability. The results were compared with surgical and pathologic findings. For tumor presence and conspicuity, combined axial and MPR images had higher values than the axial only images. For evaluation of tumoral extent, there was no difference between the two image sets for either reader. The accuracy for tumor extent was lower in hilar cancer than in extrahepatic bile duct cancer. For evaluation of vascular involvement and resectability, the area under the receiver operating characteristic curve of axial images was not significantly different from that of the reformatted images.The addition of MPR images to the standard axial images did not significantly improve the diagnostic performance of MDCT in the evaluation of the bile duct cancer.     

Can independent coronal multiplanar reformatted images obtained using state-of-the-art MDCT scanners be used for primary interpretation of MDCT of the abdomen and pelvis? A feasibility study

PURPOSE: To evaluate if coronal reformatted images can be used for primary interpretation of MDCT of the abdomen and pelvis using 64-slice MDCT. MATERIALS AND METHODS: IRB approval was obtained. We reviewed MDCT studies of the abdomen and pelvis of 220 consecutive patients performed with 64 row MDCT with constant scanning parameters. Based on a 0.625mm raw data set, transverse images were reconstructed at 5mm and coronal images at 3mm using standard reconstruction algorithms. Reader familiarity was achieved by simultaneous evaluation of transverse and coronal reformats in an initial group of 20 separate cases for findings in consensus. Two subsequent phases of image analysis were then performed in two groups of 100 patients each. In the first phase two radiologists evaluated the added utility of simultaneous review of MDCT of transverse and coronal reformatted images over transverse images alone in 100 consecutive patients referred for MDCT of the abdomen and pelvis. In the second phase, the same radiologists evaluated whether coronal multiplanar reformats could be used for primary interpretation of MDCT of the abdomen and pelvis in a separate but similar cohort of 100 consecutive abdominopelvic MDCT studies. The number of lesion(s), their location, size of smallest lesion, presence of artifacts and likely diagnosis were noted at each image interpretation. Image quality and confidence for interpretation was evaluated using five-point and three-point scale, respectively. The time required for primary interpretation of coronal reformats and transverse images were recorded. Statistical analysis was performed using Wilcoxon signed rank test. RESULTS: Both readers detected additional findings (n=37, 35), respectively, on simultaneous review of transverse and coronal reformats as compared with transverse images alone (p<0.001). Excellent interobserver agreement was noted (r=0.94-0.96). Both readers detected additional findings (n=62, 53), respectively, on independent review of coronal reformats as compared with transverse images alone (p<0.001). Readers' confidence was also found to be higher on coronal evaluations as compared to axial images (p<0.01). There was good interobserver agreement between the two readers. CONCLUSION: Independent coronal multiplanar reformatted images obtained using state-of-the-art MDCT scanners show promise as the preferred orientation and can be useful for primary interpretation of MDCT of the abdomen and pelvis.     

颞骨平行枕眶线多层螺旋CT扫描法及其价值

目的:探讨以平行枕眶线扫描图像为基础的常规轴位和冠状位MPR图像是否能够取代直接轴位和冠状位图像。方法:三位医师分别观察50例颞骨CT扫描图像,分析直接常规轴位(25例)、冠状位(25例)CT扫描图像和其相应的常规轴位、冠状位MPR图像显示颞骨结构的差异。结果:所有观察者均认为直接常规轴位、冠状位CT扫描图像略优于相应的轴位、冠状位MPR图像。直接轴位、冠状位CT扫描图像和相应的轴位、冠状位MPR图像的质量差异较小。结论:以平行枕眶线扫描图像为基础的常规轴位和冠状位MPR图像可取代直接轴位和冠状位扫描图像。     

Benefits of routine use of coronal and sagittal reformations in multi-slice CT examination of the abdomen and pelvis

AIM: To evaluate the usefulness of coronal and sagittal reformations from isotropic abdomino-pelvic computed tomography (CT) examinations. METHODS: Fifty consecutive abdomino-pelvic CT examinations were reconstructed into two sets of axial source images: 0.9 mm section width with 0.45 mm reconstruction interval (isotropic) and 4 mm section width with 3 mm reconstruction interval. The isotropic dataset was reformatted into coronal and sagittal stacks with 4 mm section widths. Three readers independently reviewed the three image sets with 4 mm section widths. The coronal and sagittal reformations were compared with the axial images, in the same sitting, for depiction of lesions in various abdominal organs. RESULTS: There was better visualization of lesions in the liver, kidneys, mesentery, lumbar spine, major abdominal vessels, urinary bladder, diaphragm and hips on the coronal reformations compared with source axial images (p<0.05). Sagittal reformations scored better than axial source images for showing lesions in the liver, thoracic spine, abdominal vessels, uterus, urinary bladder, diaphragm and hips (p<0.05). The coronal and sagittal series showed significant additional information in 23 and 17% of patients, respectively. CONCLUSION: Radiologists should consider the routine review of at least one additional plane to the axial series in the interpretation of abdomino-pelvic CT studies.     

Assessment of vascular invasion in pancreatic head cancer with multislice spiral CT: value of multiplanar reconstructions

The use of multiplanar reconstructions (MPRs) generated from multislice spiral CT (MSCT) data sets in the preoperative assessment of vascular invasion in pancreatic cancer was evaluated. Forty patients underwent biphasic high-resolution MSCT prior to surgery for pancreatic head cancer. Image reconstruction included thin-slice axial, sagittal and coronal MPRs as well as an MPR perpendicular to the course of a major peripancreatic vessel in proximity to the tumor. CT criteria for vascular invasion were: (1) circumferential involvement >180° and (2) vessel narrowing. Imaging findings of 52 vessels were correlated with surgical and histopathological reports. Regarding the CT criterion circumferential involvement, vascular invasion was demonstrated on axial MPRs with a sensitivity and specificity of 58 and 97%. For the assessment with coronal and sagittal MPRs sensitivity was only 47%. Vascular invasion was recognized best on perpendicular MPRs with a sensitivity, specificity and accuracy of 74, 97 and 88%, respectively. Vessel narrowing was a less reliable CT criterion for vascular invasion, mainly due to the lower specificity of 91% obtained with each available MPR. Thin-slice MPRs oriented perpendicularly to a possibly invaded vessel exactly depict the grade of circumferential involvement and thus have the capability to improve the assessment of vascular invasion in pancreatic cancer.     

MDCT of thoraco-abdominal trauma: an evaluation of the success and limitations of primary interpretation using multiplanar reformatted images vs axial images

To assess whether independent evaluation of coronal and sagittal reformatted images can replace axial images for primary interpretation of multidetector row computed tomography (MDCT) images in patients with thoraco-abdominal trauma. 111 (M/F 69:42) patients with acute chest or abdominal trauma underwent 16-channel MDCT. Coronal and sagittal multiplanar reformatted (MPR) images were generated from thin-section axial images. Two radiologists independently interpreted the MPR images first followed by axial images for both imaging findings as well as adequacy of image quality. Differences between independent reader review of axial and MPR images were assessed using the Wilcoxon signed rank test. There was no significant difference in soft tissue findings identified on MPR vs axial images for either reader, p = 0.91 and 0.34, respectively. However, both readers identified more skeletal findings on the MPR as compared to the axial images, p = 0.026 and 0.040, respectively. There was no significant difference between the readers in their interpretation of axial (soft tissue, p = 0.56; skeletal, p = 0.65) or MPR (soft tissue, p = 0.32; skeletal, p = 0.65) findings. More skeletal findings were identified during the isolated review of MPR as compared to axial images alone. However, the use of MPR images alone still resulted in an unacceptably high number of missed soft tissue and even skeletal findings. A combined approach where both data sets are simultaneously available is therefore preferred.     

Value of multiplanar reformations (MPR) in multidetector CT (MDCT) of acute vertebral fractures: do we still have to read the transverse images?

OBJECTIVE: To determine the value of multiplanar reformations (MPRs) in multidetector computed tomography (MDCT) diagnosis of acute vertebral fractures and to assess the necessity to read the whole set of transverse images. METHODS: Retrospectively, 56 MDCT of 55 patients with acute vertebral fractures were included. The images were analyzed by two radiologists in a consensus procedure. First, the diagnosis was made exclusively from sagittal and coronal MPRs; secondly, the transverse images were analyzed with knowledge of the MPRs. Diagnostic accuracy is given as percentage. Image amounts were compared using the Wilcoxon test. RESULTS: In 244 vertebral bodies, all 70 fractured vertebrae were diagnosed on reviewing MPRs only. There were no false positive cases. In 2/70 fractures, the anatomically exact diagnosis was complemented by reading the transverse images. Forty-two of 43 unstable fractures were diagnosed correctly on MPRs only. With preference of MPR reading, the total number of images to be analyzed could be reduced significantly (P < 0.01). CONCLUSION: Reading of MPRs alone is a feasible approach for correct assessment of vertebral fractures and classifying them into stable/unstable, if MPRs are done properly. Transverse images must be analyzed in complex fractures or uncertain findings.     

Benefits of 3D technique in guiding percutaneous retroperitoneal biopsies

Purpose

This study aimed to assess the usefulness and advantages of multiplanar reformations (MPR) during multidetector-row computed tomography (MDCT)-guided percutaneous fine-needle aspiration biopsy (FNAB) and core biopsy of retroperitoneal lesions that are difficult to access with the guidance of ultrasound and axial CT alone owing to overlying bony structures, large vessels or abdominal organs.

Materials and methods

MDCT-guided retroperitoneal FNAB and core biopsy was performed on 14 patients with suspected retroperitoneal neoplasm. We used MPR images (sagittal and coronal) obtained with a six-detector-row MDCT scanner and 20?C22 gauge Chiba needles.

Results

Using MDCT with 3D MPR allowed biological samples to be obtained in all cases (ten cytological and four histological) and diagnostic samples in 11/14 cases (78.5%). Histological samples were deemed adequate for diagnostic assessment in all cases and cytological samples in 7/10 cases (70%).

Conclusions

MPR images allowed sampling of retroperitoneal lesions until now considered unreachable with the guidance of axial MDCT alone. Compared with the conventional procedure, the use of MPR images does not increase the procedure time.     

Comparison between coronal reformatted images and direct coronal CT images of the swine lung specimen: assessment of image quality with 64-detector row CT

The aims of this study were to compare the image quality of coronal multiplanar reconstruction (MPR) images from axial spiral images with that of direct coronal spiral and sequential images, and to estimate and analyse the effect of an incremental change on the image quality using 64-detector row CT. 12 swine lungs were used. Five kinds of images from each lung specimen were obtained using 64-detector row CT. All images were analysed by categories and grades, and the direct coronal sequential images were used as the reference standard for the image quality. Statistical analysis was performed for the following categories: (i) inter-observer reliability, (ii) interaction between the observers and images, (iii) image analysis, (iv) anatomical structural analysis of each observer, (v) stair-step artefact and (vi) background noise. The overall image quality and the image quality of all anatomical structures of coronal MPR images with 0.67 mm slice increments were inferior to the image quality of the other images; this difference was statistically significant (p<0.05). Stair-step artefact was detected on coronal MPR images, and was more prominent on coronal MPR images with 0.67 mm slice increments than on coronal MPR images with 0.34 mm slice increments. The most severe background noise was detected on the direct coronal sequential images, but there was no significant difference between the direct coronal sequential images and the direct coronal spiral images. Background noise was least prominent on coronal MPR images with 0.67 mm slice increments. The increment process is important for improving the image quality of MPR images even when using 64-detector row CT. Coronal MPR images with 0.34 mm slice increments using 64-detector row CT showed a similar image quality to that obtained from the direct coronal images, and can be used instead. This means that the coronal MPR images obtained with 64-detector row CT could be as useful for evaluating the lung parenchyma as the axial high-resolution CT images.     

Petrosal bone: coronal reconstructions from axial spiral CT data obtained with 0.5-mm collimation can replace direct coronal sequential CT scans.

PURPOSE: To investigate whether coronal multiplanar reconstruction (MPR) images of the petrosal bone from axial spiral computed tomographic (CT) data obtained with 0.5-mm collimation can replace direct coronal sequential CT scans obtained with 0.5- or 1.0-mm collimation. MATERIALS AND METHODS: The differences in diagnostic quality between thin-section coronal sequential CT scans of 24 petrosal bones in 12 patients and matched MPR images were assessed by five observers. The matched MPR images were calculated with both trilinear and tricubic interpolation. Image resolution was determined by measuring the three-dimensional point spread function. RESULTS: All observers preferred tricubically interpolated MPR images over trilinearly interpolated images. Subjective differences in image quality between direct coronal scans and matched tricubically interpolated MPR images were small. Only the direct coronal scans with the highest image quality (0.5-mm collimation, 465 mAs) were judged to be slightly better than the matched MPR images. With regard to direct coronal scans obtained at 245 mAs and/or 1.0-mm collimation, either there was no preference or the MPR images were preferred. CONCLUSION: Coronal MPR images from axial spiral CT obtained with 0.5-mm collimation can replace direct coronal sequential CT scans.     

Multidetector-row CT of right hemidiaphragmatic rupture caused by blunt trauma: a review of 12 cases

AIM: To determine the usefulness of multidetector-row CT (MDCT) with multiplanar reformatted (MPR) images in the sagittal and coronal plane in diagnosing acute right hemidiaphragmatic rupture. MATERIALS AND METHODS: Twelve patients were identified who received chest and abdominal MDCT after major blunt trauma diagnosed with right diaphragmatic injury. Sagittal and coronal reformations were performed in all cases. The images were retrospectively reviewed by two experienced radiologists for signs of right diaphragm injury, such as direct diaphragm discontinuity, the "collar sign", the "dependent viscera sign", and intra-thoracic location of herniated abdominal contents. RESULTS: Of the 12 cases of right hemidiaphragm rupture, diaphragm discontinuity was seen in seven (58%) cases, the collar sign in five (42%), the dependent viscera sign in four (33%), and transdiaphragmatic herniation of the right colon and fat in another. Two variants of the collar sign were apparent on high-quality sagittal and coronal reformations. The first, termed the "hump sign", describes a rounded portion of liver herniating through the diaphragm forming a hump-shaped mass, and the second, termed the "band sign," is a linear lucency across the liver along the torn edges of the hemidiaphragm. The hump sign occurred in 10 (83%) patients and the band sign in four (33%). CONCLUSION: MDCT is very useful in the diagnosis of right hemidiaphragm injury caused by blunt trauma when sagittal and coronal reformatted images are obtained, and should allow more frequent preoperative diagnosis.     

Slice profile characteristics of MPR images in multi-slice CT

Few studies have investigated the detailed imaging characteristics of multiplanar reconstruction (MPR) images, which have come to be used in imaging diagnosis. The purpose of this study was to evaluate the slice profile characteristics of MPR images. The slice profile of a coronal image was measured by the bead method. Moreover, it assumed that the slice profile of an MPR image became a convolution of the square profile corresponding to the nominal slice thickness and line spread function (LSF) of an axial image, and the simulation was performed. The nominal slice thicknesses of the original axial image and coronal image were 1.0 mm, 2.0 mm, and 3.0 mm. Three reconstruction kernels (B20, B30, and B40) of the original axial image were used. The results of measurement revealed that the full width at half maximum (FWHM) values were 1.7 mm for reconstruction kernel B20 and 1.3 mm for reconstruction kernel B40 in the case of a nominal slice thickness of 1.0 mm. The simulated and measured modulation transfer factors (MTF) were in close agreement. Then the slice profile of the coronal (sagittal) MPR image forms by the convolution of a LSF of the y- (x-) direction and the square profile with a nominal MPR slice width, and is affected by the reconstruction kernel.     

多平面重组对正常成人圆孔的研究

目的:采用多层螺旋CT高分辨扫描和多平面重组(MPR)技术,多方位显示圆孔的正常形态并进行测量分析。方法:对167例正常受试者行高分辨薄层扫描。在工作站上对圆孔进行MPR重组,观察圆孔及其通连结构形态,测量其径限值。结果:MPR图像对圆孔的显示率为100%,圆孔在横断面和矢状面上呈管型、孔型或窗型,冠状面上多为圆形或椭圆形。其平均长度、前口和后口径分别为:(0.32±0.15)cm、(0.33±0.05)cm和(0.31±0.05)cm,同侧圆孔前口大于后口。结论:HRCT薄层扫描及MPR重组可清晰显示圆孔及其通连结构,有利于对其解剖形态的观察和径限的测量,为临床诊断及治疗方案的制定提供科学数据。     

Multislice computed tomography of the sternum: which image reconstruction do we need?

OBJECTIVE: To assess the diagnostic value and to optimize image reconstruction for multislice spiral computed tomography (MSCT) of the sternum. MATERIALS AND METHODS: Forty patients underwent MSCT of the sternum using a standardized examination protocol (4x1 mm or 4x2.5 mm collimation; 120 kV, 120 mAseff). Axial images with an effective slice thickness of 1.25 mm or 3 mm and an increment of 0.8 mm or 1 mm were reconstructed. Coronal and sagittal reformations with a slice thickness between 2 mm or 3 mm and 5 mm and a slice distance ranging from 1 mm to 4 mm (overlap 1 mm) were calculated. In all patients, additional plain film radiographs (n=9) or clinical follow-up data were available. Image quality was assessed visually using a five-point grading scale. RESULTS: In all patients, the correct diagnosis was established using multiplanar reformats (MPR) exclusively. Best image quality for MPR was achieved using a slice thickness of 3 mm and a slice distance of 2 mm. Images acquired with a 4x1 mm collimation proved superior to images reconstructed from data obtained with a 4x2.5 mm collimation. CONCLUSION: MPR from MSCT data are a valuable tool for the diagnosis of sternal pathologies. For best image quality the thinnest possible collimation should be chosen.     

Usefulness of the long-axis and short-axis reformatted images of multidetector-row CT in evaluating T-factor of the surgically resected pancreaticobiliary malignancies

PURPOSE: To evaluate the diagnostic efficacy of curved planar reformations along the duct (long-axis CPR) and series of reformations perpendicular to the duct (short-axis MPR) in evaluating T-factors of pancreaticobiliary malignancy. MATERIALS AND METHODS: Twenty-five patients with surgically proven pancreaticobiliary malignancy (12 bile duct cancers and 13 pancreas cancers) were evaluated. A dynamic study was performed with multidetector-row CT with four detectors, and reconstructed with 1mm thickness and intervals. Tracing the center of the duct system on axial images, long-axis CPR images and serial short-axis MPR images were obtained. Two radiologists interpreted the T factor of the diseases three times: session (1), axial images only; session (2), axial, coronal and sagittal multiplanar reformation images; and session (3), axial, long-axis CPR, and short-axis MPR images. Receiver operating characteristic curves were analyzed. RESULTS: In evaluations of bile duct cancer, Az values of (3) (0.95, 0.92) were higher than those of (1) (0.89, 0.88) and (2) (0.92, 0.89), with some significant differences. In evaluations of pancreas cancer, Az values of all interpretations were almost equal. CONCLUSION: Long-axis CPR and short-axis MPR images were suggested to be useful as additional images to the original axial images in evaluating the local extension of bile duct carcinomas.     

Can independent coronal multiplanar reformatted images obtained using state-of-the-art MDCT scanners be used for primary interpretation of MDCT of the abdomen and pelvis? A feasibility study

PurposeTo evaluate if coronal reformatted images can be used for primary interpretation of MDCT of the abdomen and pelvis using 64-slice MDCT.Materials and methodsIRB approval was obtained. We reviewed MDCT studies of the abdomen and pelvis of 220 consecutive patients performed with 64 row MDCT with constant scanning parameters. Based on a 0.625 mm raw data set, transverse images were reconstructed at 5 mm and coronal images at 3 mm using standard reconstruction algorithms. Reader familiarity was achieved by simultaneous evaluation of transverse and coronal reformats in an initial group of 20 separate cases for findings in consensus. Two subsequent phases of image analysis were then performed in two groups of 100 patients each. In the first phase two radiologists evaluated the added utility of simultaneous review of MDCT of transverse and coronal reformatted images over transverse images alone in 100 consecutive patients referred for MDCT of the abdomen and pelvis. In the second phase, the same radiologists evaluated whether coronal multiplanar reformats could be used for primary interpretation of MDCT of the abdomen and pelvis in a separate but similar cohort of 100 consecutive abdominopelvic MDCT studies. The number of lesion(s), their location, size of smallest lesion, presence of artifacts and likely diagnosis were noted at each image interpretation. Image quality and confidence for interpretation was evaluated using five-point and three-point scale, respectively. The time required for primary interpretation of coronal reformats and transverse images were recorded. Statistical analysis was performed using Wilcoxon signed rank test.ResultsBoth readers detected additional findings (n = 37, 35), respectively, on simultaneous review of transverse and coronal reformats as compared with transverse images alone (p < 0.001). Excellent interobserver agreement was noted (r = 0.94–0.96). Both readers detected additional findings (n = 62, 53), respectively, on independent review of coronal reformats as compared with transverse images alone (p < 0.001). Readers’ confidence was also found to be higher on coronal evaluations as compared to axial images (p < 0.01). There was good interobserver agreement between the two readers.ConclusionIndependent coronal multiplanar reformatted images obtained using state-of-the-art MDCT scanners show promise as the preferred orientation and can be useful for primary interpretation of MDCT of the abdomen and pelvis.