Routine isotropic computed tomography scanning of chest: value of coronal and sagittal reformations

OBJECTIVE: We sought to evaluate the usefulness of coronal and sagittal reformations from isotropic chest computed tomography (CT) examinations. METHODS: A total of 30 chest CT examinations were reconstructed into 2 sets of axial source images: 0.9-mm slice width with 0.45-mm reconstruction interval (isotropic) and 4-mm slices with 3-mm reconstruction interval. The isotropic dataset was reformatted into coronal and sagittal stacks with 4-mm slices. Three readers reviewed the image sets with 4-mm slice widths. Coronal and sagittal reformations were compared at the same sitting to axial images for depiction of anatomy and disease in the aorta, pulmonary arteries, hilar regions, mediastinum, lung parenchyma, pleura, diaphragm, thoracic spine, ribs, and trachea. A 5-point scale was used to determine whether nonaxial reformations showed anatomy and disease significantly better, somewhat better, same, somewhat worse or significantly worse than equivalent thickness axial source images. A 3-point scale was used to score if nonaxial image sets showed no, some, or significant additional information compared with the axial plane regarding the main diagnosis. RESULTS: There was better visualization of the hilar regions, diaphragm, spine, and trachea on the coronal reformations compared with source axial images (P < 0.05). Sagittal reformations scored better than axial source images for aorta, pleura, diaphragm, spine, and ribs (P < 0.05). The coronal and sagittal series showed significant additional information in 11% and 9% of patients, respectively. CONCLUSION: Radiologists should consider the use of one or both of coronal and sagittal planes in addition to the axial series in routine interpretation of chest CT.     

Isotropic CT examination of abdomen and pelvis diagnostic quality of reformat

RATIONALE AND OBJECTIVES: To evaluate the image quality of axial and coronal reformats obtained from isotropic resolution abdomino-pelvic computed tomography (CT) examinations. MATERIALS AND METHODS: Thirty consecutive patients with intravenous contrast-enhanced abdomino-pelvic CT examinations (Brilliance 40, Philips Medical Systems, Cleveland, OH) were enrolled for the study. The raw data were reconstructed into two sets of source axial images: 0.9-mm slice widths with 0.45-mm reconstruction interval (isotropic resolution) and 4-mm slice widths with 3-mm reconstruction interval (anisotropic resolution: group A). Isotropic data set was reformatted into axial and coronal stacks (groups B and C, respectively) with 4-mm slice width and 3-mm interval. Three independent readers evaluated stacks A to C using a 3-point scale for resolution of hepatic vessels, edge sharpness of kidneys, respiratory motion artifact, reconstruction artifact, noise, and overall image quality. RESULTS: There was no statistical difference among the groups A to C for vessel resolution, motion artifact, noise, and overall quality. The scores given to group C were significantly lower than those to groups A and B for reconstruction artifacts. There was no difference among groups A to C for overall impression of image quality. The interreader agreements were excellent for axial images (groups A and B) and moderate for coronal reformats. CONCLUSION: Isotropic scanning of the abdomen and pelvis allows creation of reformats with similar image quality as similar thickness axial source images. These reformats are of sufficient quality to form the basis of clinical interpretation.     

Fracture detection in the cervical spine with multidetector CT: 1-mm versus 3-mm axial images

BACKGROUND AND PURPOSE: Multidetector CT imaging of the cervical spine performed with submillimeter collimation allows for the production of excellent quality multiplanar reformations and reconstructed axial images at any chosen section thickness. Currently there is no consensus on what images need to be reviewed for accurate diagnosis of cervical spine fractures. Our study assesses whether 1-mm axial images provide any diagnostic advantage over 3-mm images in detection of cervical spine fractures when read in conjunction with multiplanar reformations.MATERIALS AND METHODS: The dataset consisted 50 cases of CT of the cervical spine and included 25 consecutive cases of cervical spine fractures and 25 matched normal CTs. Axial images were reconstructed at 1- and 3-mm thicknesses, and the sagittal and coronal reformations between 2- and 3-mm thicknesses. Four radiologists reviewed all 50 of the cases twice, once at 1 mm and once at 3 mm. Reads were separated by 3 months.RESULTS: There were 39 fractures in total, consisting of 29 clinically significant and 10 insignificant fractures. Thirty-three fractures were missed in 400 reads. Twenty-one misses were at 3 mm (sensitivity, 86%), and 12 misses at 1 mm (sensitivity, 92%; P = .228). Ten of 33 misses were of clinically significant fractures, 6 misses at 1 mm and 4 at 3 mm (P = .52). Twenty-three of 33 misses were of clinically insignificant fractures, 6 at 1 mm and 17 at 3 mm (P = .006).CONCLUSION: For detection of clinically important fractures, there is no significant difference between 1- and 3-mm axial images when read in conjunction with multiplanar reformations.

Multidetector CT imaging of the cervical spine performed with submillimeter collimation allows for the production of excellent quality multiplanar reformations and reconstructed axial images at any chosen section thickness. The large image dataset and the ability to reconstruct a vast number of images leads to issues with data storage and time needed to review the examination. Currently there is no consensus on what images need to be reviewed for accurate diagnosis of cervical spine fractures. The standard in our institution is to read 1-mm axial images with sagittal and coronal reformations. The purpose of our study was to assess whether 1-mm axial images provide any diagnostic advantage over 3-mm images in the detection of cervical spine fractures when read in conjunction with multiplanar reformations, thereby providing objective data in the formulation of guidelines for the assessment of cervical spine CTs.     

Acute abdomen: Added diagnostic value of coronal reformations with 64-slice multidetector row computed tomography

RATIONALE AND OBJECTIVES: We sought to assess retrospectively the added value of coronal reformations from isotropic voxels obtained with 64-slice multidetector row computed tomography (CT) of the acute abdomen. MATERIALS AND METHODS: This retrospective study was approved by the institutional review board and informed consent was waived. Multidetector helical 64-section CT (section thickness, 0.6 mm; pitch 1.75; table speed 35 mm/sec) was performed in 100 patients (60 women and 40 men; age range, 9-/+85 years; mean age, 45.2 years) with acute nontraumatic abdominal pain who had been referred from the emergency department. Axial images were reconstructed with 5-mm-thick sections at 5-mm intervals. The second data set was reformatted coronally, with 3-mm-thick sections at 3-mm intervals. Four independent, blinded readers with various level of training interpreted first the axial scans alone and then followed immediately by the coronal scans. Confidence in the visualization of anatomy and pathology was scored on a 5-point scale. The final diagnosis was determined by surgical and pathologic reports and by clinical follow-up in those who did not undergo surgery. RESULTS: Based upon the individual patient's clinical history and other comorbid factors, 92 patients received intravenous contrast and 90 patients received oral contrast. In 45 patients, no CT abnormalities were detected for an explanation of the abdominal pain. Mean sensitivity and specificity of axial CT alone were 92.5% and 91%, respectively. No significant differences in sensitivity and specificity were observed for the use of combined axial and coronal images. For the most inexperienced reader, the coronal reformations were helpful in 95% of cases, while for the most experienced reader, the coronal reformations were helpful in 35% of the cases. The coronal images were deemed helpful in an average of 62.3% of the cases for the four readers. However, diagnosing subtle pathology in the abdominal wall was difficult on coronal reformations alone. Overall, coronal reformations improved diagnostic confidence and interobserver agreement over axial images alone for visualization of normal abdominal structures and in the diagnosis of abdominal pathology. CONCLUSION: Axial and coronal reformations of 64-section multidetector row CT have equal sensitivity and specificity for the diagnosis of acute abdominal pathology. However, coronal reformations improved the diagnostic confidence for all readers but most significantly for the least experienced. Therefore, radiology departments with residents should consider routinely generating coronal images in patients with acute abdominal pain.     

Fractures of the cervical vertebrae: diagnosis with multi-slice spiral CT]

PURPOSE: It is the aim of this study to investigate the efficiency of multislice helical CT for the diagnosis of cervical spine fractures. The advantages of this technique are demonstrated by case reports. MATERIAL AND METHODS: The entire cervical spine or selected vertebral bodies of 66 patients with cervical spine fractures known from preceding plain films were scanned with a multislice helical CT. The CT-scans were obtained with a slice thickness of 1.25 mm and with two different pitches (0.75 or 1.5) and table speeds (3.75 or 7.5 mm/rot.). Additionally, sagittal and coronal reformations were performed. RESULTS: The mean scan-time for the cervical spine was 13 seconds. High quality sagittal and coronal reformations were obtained from axial images within a few minutes. Fractures of the dens (n = 17) and of the vertebral body of C3-C7 (n = 12) occurred predominantly. CONCLUSION: Multislice helical CT is an effective tool to diagnose fractures of the cervical spine rapidly and exactly.     

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.     

Subtle pathology detection with multidetector row coronal and sagittal CT reformations in acute head trauma

We sought to analyze retrospectively the advantages of coronal and sagittal reformations obtained with multidetector row computed tomography (CT) in patients with acute head trauma. Multidetector 16-section CT was performed in 200 patients (110 male and 90 female; age range, 3–87 years; mean age, 45 years) with acute head trauma. Scans were performed sequentially, and axial 5-mm-thick slices were obtained from base of skull to vertex. The source data set was reformatted in coronal and sagittal planes, with 2-mm-thick sections at 2-mm intervals. Images were analyzed retrospectively by two independent, blinded readers. The final diagnosis was determined by clinical follow-up. CT imaging abnormalities were detected in 55 out of 200 patients who were scanned for head trauma. Acute traumatic intracranial abnormality was detected on axial scans in 45 patients. Subtle findings were confirmed on coronal and sagittal CT reformations in ten cases, and these were undetected initially on axial CT. Coronal and sagittal reformations confirmed subtle findings in 18.2% (10/55) of the cases (P = 0.001). Indeterminate neuroimaging findings confirmed by coronal and sagittal CT head reformations include tentorial and interhemispheric fissure subdural hemorrhage, subarachnoid hemorrhage, and inferior frontal and temporal lobe contusions. Coronal and sagittal CT head reformations improve the sensitivity and diagnostic confidence in the clinical setting of acute trauma. Overall, coronal and sagittal reformations improved diagnostic confidence and interobserver agreement over axial images alone for visualization of normal structures and in the diagnosis of acute abnormality.     

Identification of the anterior ethmoid arteries on thin-section axial images and coronal reformatted orbit images by means of multidetector row CT

AIM: The aim of this study was to identify anterior ethmoid arteries on thin-section axial images and coronal reformatted images of the orbits using multidetector row computed tomography (CT). MATERIALS AND METHODS: One hundred and thirty-two patients underwent paranasal CT using a 16-row detector CT (n=59) or a 6-row detector CT machine (n=73) at 1 or 1.25 mm section width, respectively. Coronal images were reformatted at section widths of 3 and 1 mm. The anterior ethmoid arteries were identified for each patient. Differences were assessed using the chi-square test. RESULTS: All CT images were of approximately average diagnostic quality. Anterior ethmoid arteries were identified in 97.5 and 96.6% at section thicknesses of 1 and 1.25 mm on the axial images, respectively. There was no statistically significant difference in the detection rate (p=0.89). On the coronal images, anterior ethmoid arteries were presented tangentially in 75.4 and 90.2% at section widths of 3 and 1 mm, respectively. The visibility of the anterior ethmoid arteries was rated significantly better on coronal images at a section width of 1 mm than on those at section widths of 3 mm (p<0.001). CONCLUSION: Thin-section axial images and coronal reformatted images using multi-detector row CT mostly depict anterior ethmoid arteries, and are useful to identify anterior ethmoid arteries for preoperative evaluation of paranasal sinuses.     

Laryngo-tracheal anastomosis: post-operative evaluation by helical CT and computerized reformations

OBJECTIVE: Our purpose was to evaluate the role of post-operative helical computed tomography (CT) and computerized reformations in patients after laryngo-tracheal segmental resection with anastomosis. METHODS: Helical CT and computerized reformations were obtained in 11 consecutive patients who underwent laryngo-tracheal resection with anastomosis for obstruction or stenosis caused by longstanding intubation or tracheostomy. Post-operative computer assisted cross-sectional area, coronal and sagittal diameter measurements at the level of maximal narrowing of the trachea were compared with clinical assessment in all patients. The additive value of various coronal and sagittal computerized reformations over axial images was subjectively evaluated by a consensus of a thoracic radiologist and a neuroradiologist who were blinded to clinical information. RESULTS: Various degrees of restriction in daily activities were reported by patients with cross-sectional area narrowing of more than 50%, by 4/6 patients with cross-sectional area of less than 90mm(2), by 4/5 and 4/6 patients with coronal or sagittal narrowing of more than 25% respectively, and by 4/5 patients with sagittal diameter of less than 12mm. All five patients with cross-sectional area stenosis of less than 50% assessed themselves as 'asymptomatic'. Sagittal multi-planar and volume rendering reformations clarified or added additional information over axial images in all six patients with significant cross-sectional area stenosis (>50%). Volume rendering scores were significantly higher than minimal intensity projection reformations (P=0.01). CONCLUSION: Our preliminary results suggest that CT-based cross-sectional area and diameter measurements of the trachea represent a clinically helpful tool for post-operative evaluation of patients with tracheoplasty. The need for post-operative endoscopy may be obviated in some cases.     

Breath-hold three-dimensional CT of the liver with multi-detector row helical CT

PURPOSE: To compare image quality on transverse source images and coronal and sagittal reformations to determine the feasibility of using single-breath-hold three-dimensional liver computed tomography (CT) with multi-detector row helical CT in patients suspected of having hepatic metastases. MATERIALS AND METHODS: Fifty-three patients underwent the protocol. Coronal and sagittal reformations were constructed. Images were reviewed for duration of scan acquisition and length and adequacy of z-axis coverage. Reformations were scored for visualization of portal and hepatic vein branches, liver edge sharpness, cardiac pulsation and respiratory motion artifacts, noise due to mottle, and overall impression. RESULTS: Mean z-axis coverage was 207 mm +/- 33 (SD) (range, 145-280 mm), with a mean acquisition time of 10.96 seconds +/- 1.78 (range, 7.73-14.93 seconds). In 44 (83%) patients, the entire liver was imaged on a single helical scan. Artifact from cardiac motion was not identified on the transverse source images in any patient but was identified on coronal images in eight (15%) and on sagittal images in seven (13%). Similarly, noise due to mottle was not identified on the transverse source images but was identified on coronal images in seven (13%) patients and on sagittal images in six (11%). CONCLUSION: It is feasible to perform single-breath-hold three-dimensional liver CT with multi-detector row helical CT technology. Reformations provide a unique perspective with which to view the liver and may improve diagnostic capacity.     

呼吸运动对PET/CT显像诊断右上腹病灶的影响

目的探讨呼吸运动对PET／CT全身显像诊断右肺底、肝顶病灶的影响。方法回顾分析100例胸部病变患者的^18F-脱氧葡萄糖（FDG）PET／CT显像结果，观察PET、CT及两者融合图像。患者在检查时平静呼吸。观察呼吸运动伪影在不同断面的特点，对右上腹可能出现定位误差的病灶加做常规屏气CT扫描。结果①6例患者因合并胸腔、腹腔积液而未列入统计，其余38．3％（36／94例）的患者PET／CT图像有明显的呼吸运动伪影，矢状面是观察呼吸运动伪影的最佳断面：②呼吸运动致肝顶在矢状面表现为“波浪状”，横断面表现为肝脏边缘模糊，冠状面表现为突入肺底的软组织密度影。③5例患者存在右肺底、肝顶病灶，其定位可能因呼吸运动造成误差。结论呼吸运动伪影是PET／CT显像中常见的现象，对右上腹病灶定位有疑问者应加做常规屏气CT扫描。     

Routine isotropic computed tomography scanning of the abdomen and pelvis

For 30 years, abdominal CT has been imaged and reviewed in the axial plane. It is now possible to carry out isotropic imaging of the whole abdomen and pelvis using a 40-channel scanner. This allows creation of coronal and sagittal reformats with the same image quality as the axial images. In this study, we present our experience of reviewing routinely coronal and, occasionally, sagittal reformats. We discuss situations where these nonaxial reformats are most beneficial.     

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.     

Evaluation of multiplanar reconstruction in CT recognition of lumbar disk disease

Axial computed tomographic (CT) images were compared with sagittal and coronal reformations and myelograms in 60 patients to evaluate the diagnostic usefulness of multiplanar reconstructions for the recognition of lumbar disk disease. The axial CT scans were most sensitive and specific. The sagittal scans were helpful in evaluating the neural foramina, the size of the disk bulge into the spinal canal, especially at L5-S1, and patients with spondylolisthesis. The coronal images were the least informative, although they contributed to the evaluation of lumbar nerve roots. The myelograms and the sagittal images were equally useful in the detection of herniated disk, but axial scans were superior to either. It was concluded that reformatted sagittal and coronal images are not required if all axial images are normal. However, when uncertainty exists or complex anatomy is being evaluated, reformatted images may be helpful, particularly for reassurance.     

Thin-section multiplanar reformats from multidetector-row CT data: utility for assessment of regional tumor extent in non-small cell lung cancer

PURPOSE: To determine the clinical utility of thin-section multiplanar reformats (MPRs) from multidetector-row CT (MDCT) data sets for assessing the extent of regional tumors in non-small cell lung cancer (NSCLC) patients. MATERIALS AND METHODS: Sixty consecutive NSCLC patients, who were considered candidates for surgical treatment, underwent contrast-enhanced MDCT examinations, surgical resection and pathological examinations. All MDCT examinations were performed with a 4-detector row computed tomography (CT). From each raw CT data set, 5mm section thickness CT images (routine CT), 1.25 mm section thickness CT images (thin-section CT) and 1.25 mm section thickness sagittal (thin-section sagittal MPR) and coronal images (thin-section coronal MPR) were reconstructed. A 4-point visual score was used to assess mediastinal, interlobar and chest wall invasions on each image set. For assessment of utility in routine clinical practice, mean reading times for each image set were compared by means of Fisher's protected least significant difference (PLSD) test. A receiver operator characteristic (ROC) analysis was performed to determine the diagnostic capability of each of the image data sets. Finally, sensitivity, specificity and accuracy of the reconstructed images were compared by McNemar test. RESULTS: Mean reading times for thin-section sagittal and coronal MPRs were significantly shorter than those for routine CT and thin-section CT (p<0.05). Areas under the curve (Azs) showing interlobar invasion on thin-section sagittal and coronal MPRs were significantly larger than that on routine CT (p=0.03), and the Az on thin-section sagittal MPR was also significantly larger than that on routine CT (p=0.02). Accuracy of chest wall invasion by thin-section sagittal MPR was significantly higher than that by routine CT (p=0.04). CONCLUSION: Thin-section multiplanar reformats from multidetector-row CT data sets are useful for assessing the extent of regional tumors in non-small cell lung cancer patients.     

The "de Sèze" magnetic imaging

The authors propose that a coronal STIR sequence with large FOV, similar to the de Sèze projection, including lumbar spine, sacrum, pelvis and hips should be obtained in all patients as part of the lumbar spine MRI protocol. For an additional few minutes of scanning time, this additional sequence could demonstrate the presence of lesions (hips, pelvis, sacrum, SI joints, retroperitoneum...) that would otherwise go undetected on standard sagittal and axial MRI images of the lumbar spine.     

Significance of sagittal reformations in routine thoracic and abdominal multislice CT studies for detecting osteoporotic fractures and other spine abnormalities

The purpose was to assess osteoporotic vertebral fractures and other spinal lesions in sagittal reformations obtained from routine multidetector computed tomography (MDCT) studies of the thorax and abdomen, to compare sagittal reformations with axial images in detecting these lesions and to investigate how frequently they were missed in the official radiology report. Routine abdominal or thoracoabdominal MDCT using a standard protocol was performed in 112 postmenopausal women. Axial images and sagittal reformations were analyzed separately by two radiologists in consensus and were compared in order to evaluate how often spinal lesions could be detected. In addition the official radiology reports were assessed to determine how many of those abnormalities were identified. Spine abnormalities were visualized in 101/112 postmenopausal women. In 27 patients osteoporotic vertebral deformities were found; 6 of these were shown in the axial images, but none of these were diagnosed in the official radiology report. Additional abnormalities included degenerative disc disease, osteoarthritis of the facet joints, scoliosis, hemangiomas and bone metastases. In only 9/101 patients spine abnormalities were mentioned in the radiology report. Sagittal reformations of standard MDCT images provide important additional information on spinal abnormalities; in particular, osteoporotic vertebral deformities are substantially better detected.     

Acute pulmonary embolism: comparison of standard axial MDCT with paddlewheel technique

PURPOSE: The purpose of this study was to evaluate the ability of rotated paddlewheel reformations for the detection of central and peripheral pulmonary embolism (PE) compared to standard axial multi detector CT (MDCT) images. MATERIAL AND METHODS: CT scans of 35 patients with PE were reviewed by three independent readers for the detection of pulmonary emboli using standard axial CT scans and reformatted paddlewheel technique. All images were evaluated in random order. MDCT examinations were performed with a collimation of 1.25 mm, a pitch of six and a reconstruction interval of 0.8mm. For each patient MIP were reformatted by using a paddlewheel arrangement with 5mm slab thickness and 5 degrees rotation. Standard of reference for PE was a consensus reading of the axial images by all three readers. RESULTS: The overall sensitivity for the axial images for the three readers ranged between 91% and 96%; for paddlewheel reformations from 78% to 83%; the specificity for both methods was 98-99%. Inter- and intraobserver agreement was also higher for axial images than for paddlewheel reformations. CONCLUSION: Comparing standard axial MDCT scans and reformatted paddlewheel images no significant difference for the detection of central PE was found, whereas for the detection of peripheral emboli standard axial images showed a significant higher percentage of detecting PE than paddlewheel reformations.     

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.     

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.