Multi Planar Research Articles

Clinical Application of Cone Beam Computed Tomography of the Rabbit Head: Part 2-Dental Disease.

Domestic rabbits are increasing in popularity as household pets; therefore, veterinarians need to be familiar with the most common diseases afflicting rabbits including dental disease. Current diagnostic approaches include gross oral examination, endoscopic oral examination, skull radiography, and computed tomography (CT). Cone beam computed tomography (CBCT), a new oral and maxillofacial imaging modality that has the capability to produce high-resolution images, has not yet been described for use in evaluating dental disease in rabbits. A total of 15 client-owned rabbits had CBCT, oral examination, dental charting, and dental treatment performed under general anesthesia. Images were evaluated using transverse and custom multiplanar (MPR), 3D, and panoramic reconstructed images. The CBCT findings were grouped into abnormalities that could be detected on conscious oral examination vs. abnormalities that could not be detected by conscious oral examination. Potential associations between the two categories were examined by pairwise Fisher’s exact test with statistical significance determined by P < 0.05. The most common findings identified on CBCT images were periodontal ligament space widening (14/15), premolar and molar malocclusion (13/15), apical elongation (13/15), coronal elongation (12/15), inflammatory tooth resorption (12/15), periapical lucency (11/15), moth-eaten pattern of osteolysis of the alveolar bone (9/15), ventral mandibular border contour changes (9/15), and missing teeth (8/15). Of the CBCT abnormalities likely to be observed on oral examination, coronal elongation (detectable on oral examination) was significantly associated with apical elongation (P = 0.029). There were no other significant associations between CBCT findings that are also clinically detectable and CBCT findings that are not be detectable on oral examination. This suggests that pathology often exists that is not apparent upon oral examination. This study establishes the common CBCT findings associated with dental disease in rabbits and demonstrates the feasibility of this technology to diagnose and plan treatment in dental disorders in this species.

Evaluation of Use of Adipose Cells in Various Procedures of Plastic Surgery and its Volumetric Quantification using High Resolution Ultrasound.

Autologous fat transfer is based on one of the principles of plastic surgery, replace like with like. It is used in wide variety of aesthetic procedures such as lip, facial augmentation and reconstructive procedures such as involutional disorders, post traumatic defects etc. This prospective study was on the use of adipose cells in various procedures of plastic surgery, the role of high resolution ultrasound in estimating the volume of the grafted fat, comparison of the results based on the different donor sites of the harvested fat and comparison of the effectiveness of grafted fat in extremities and craniofacial region. In this prospective study a total of 34 patients underwent fat grafting procedure at various sites of the body from May 2012 till November 2013. After noting the details of the patient, details of the defect, laboratory and radiological investigations, the consent for the fat grafting procedure was taken. Clinical photographs and High Resolution Ultrasound (HRUS) volume estimation was done on a regular basis as per the protocol. Out of 34 patients, 29 patients underwent free fat grafting and five patients underwent derma fat grafting. HRUS at six months revealed a mean 73.5% and 63.5% of the injected fat remained in contour deformity in extremities and craniofacial region respectively. HRUS at one year revealed a mean 57.4% and 41.4% of the injected fat remained in contour deformity in extremities and craniofacial region respectively. HRUS is an excellent handy modality for serial volume estimation, cost-effective, non-invasive, multi planar modality, does not require any preparation, and easily done outdoor procedure. Follow up is a practical proposition. Autologous fat grafting is a safe procedure with no significant complications other than fat reabsorption and it can be done under local anaesthesia in contour deformity of smaller areas. Disadvantage of autologous fat grafting is the fat reabsorption needing multiple sittings.

多断面変換画像 (MPR) と 3 次元 CT 画像から見た気管内異物の 2 例

多断面変換画像 (MPR) と 3 次元 CT 画像から見た気管内異物の 2 例

Method and phantom to study combined effects of in-plane (x,y) and z-axis resolution for 3D CT imaging.

Increasingly, the advent of multislice CT scanners, volume CT scanners, and total body spiral acquisition modes has led to the use of Multi Planar Reconstruction and 3D datasets. In considering 3D resolution properties of a CT system it is important to note that both the in‐plane (x,y) and z‐axis (slice thickness) influence the visualization and detection of objects within the scanned volume. This study investigates ways to consider both the in‐plane resolution and the z‐axis resolution in a single phantom wherein analytic or visualized analysis can yield information on these combined effects. A new phantom called the “Wave Phantom” is developed that can be used to sample the 3D resolution properties of a CT image, including in–plane (x,y) and z‐axis information. The key development in this Wave Phantom is the incorporation of a z‐axis aspect of a more traditional step (bar) resolution gauge phantom. The phantom can be examined visually wherein a cutoff level may be seen; and/or the analytic analysis of the various characteristics of the waveform profile by including amplitude, frequency, and slope (rate of climb) of the peaks, can be extracted from the Wave Pattern using mathematical analysis such as the Fourier transform. The combined effect of changes in in‐plane resolution and z‐axis (thickness), are shown, as well as the effect of changes in either in‐plane resolution, or z‐axis thickness. Examples of visual images of the Wave pattern as well as the analytic characteristics of the various harmonics of a periodic Wave pattern resulting from changes in resolution filter and/or slice thickness, and position in the field of view are shown. The Wave Phantom offers a promising way to investigate 3D resolution results from combined effect of in‐plane (x‐y) and z‐axis resolution as contrasted to the use of simple 2D resolution gauges that need to be used with separate measures of z‐axis dependency, such as angled ramps. It offers both a visual pattern as well as a pattern amenable to analytic analysis using Fourier Transform methods, and is believed to offer an image quality test closer to the diagnostic task where the 2D image has the hidden third (z) axis effects.PACS number(s): 87.57.Q‐

Controversy and confusion in preoperative imaging precise staging of gastric cancer

AJCC determined the pathological standards for staging of gastric cancer, but no corresponding radiological signs of a single stage were described or documented. The vacancy of authority standards and limitation of the existing radiological modalities has caused the "stage fright" of the radiologists during the clinical practices. The controversy and confusion under different cognitive aspects can be summarized as follows: (1) If the gastric submucosal layer is not detected, it can only take the indirect standard of "50% thickness ratio" to distinguish T1 and T2. (2) T2 tumors may be overstaged as T3, as a result of the undetectable thin subserosa layer. (3) T3 tumors may be overstaged as T4, because of the inflammatory and fibrosis strands and spiculations near the serosa, and the existence of the gastric bare area. (4) The diagnostic imaging criteria for T4b are still controversial, and the opinions are not uniform about the resectable signs. Some significantly infiltrated unresectable tumors lack typical radiology signs. (5) Size is still the widely-used direct criterion for the diagnosis of lymph node metastasis, however the accuracy of N staging is only 50%-70%. (6) It lacks the typical sign for the diagnosis of early peritoneal metastasis, with a diagnostic sensitivity of only 50%. There is no fundamental breakthrough for the existing imaging modalities to solve the above controversies on the preoperative precise staging. However, the situations can be improved by standardization of the examination and reporting process (oral filling, multi-phase enhancement, multi planar reconstruction, and window width/level technique, etc.), the exploration of the fine signs(hyperattenuating serosa sign, smudge sign, etc.) and the exploration of new modalities (spectral CT, diffusion weighted MR imaging, etc.).

Role of MRI in delineation of internal derangement of knee in trauma patients

Introduction: Knee joint is one of the most commonly injured joints, as an isolated injury or a frequent component in a multiple trauma patient. Knee joint injury is a significant cause of morbidity in young and active individuals especially amongst sports person, laborers, soldiers and military recruits. Multiple imaging modalities are currently being used to evaluate various pathological conditions of the knee including conventional radiography, CT scan, sonography , nuclear medicine and MR Imaging. Multi planar imaging and excellent soft tissue contrast has made the MRI an ideal modality for imaging of complex anatomy of knee joint in trauma patient. Objective: To study the diagnostic accuracy &amp; efficacy of MRI in evaluation of internal derangement of knee joint in trauma patient. Material &amp; Method: 44 cases with history of trauma were evaluated by Siemens magnetom vision plus 1.5 tesla MRI machine. Results: Mean age of patient - 32.2 years. Count of male patients exceeded the count of female patients. ACL injury was observed in 81.8%, PCL injury in 6.8%, MCl in 11.3%, LCL in 2.3%, medial meniscal tear in 45.5%, joint effusion in 95%. Conclusion: MRI emerged as a front line investigation for the assessment of internal derangement of knee joint in trauma patient.

2D and 3D CT Diagnosis of Traumatic Incudostapedial Joint Separation.

A 55-year-old woman was referred to our department of Diagnostic Radiology for persistent conductive hearing loss on the left side (−30 to 40 decibels in all frequencies) accompanied by dizziness in the waning of a serious head injury. Three months before the patient had heavily fell on the head in a stairwell with the result of diffuse cerebral (intraparenchymal hematoma) and extracerebral (subdural hematoma and subarachnoid hemorrhage) lesions and that mostly at the contralateral right cerebral hemisphere. The patient remained in coma for three weeks. High-definition multidetector CT showed a left middle ear which was actually completely free of residual fluid or blood allowing a perfect 2D and 3D analysis of the petrous bone and of the ossicular chain. A thin fracture was crossing the squamous part of the temporal bone to extend through the wall of the external auditory. It was prolongated by a longitudinal fracture of the temporal petrous through the middle ear (black arrow on Fig. A). 2D multi planar reconstructions followed by selective 3D volume rendering of the ossicles perfectly identified an incudostapedial joint separation (white arrow on Fig. B).

English

OBJECTIVES: To determine the, mode of injury, location, age and sex distribution involving the various bones of facio-maxillary region seen during the time period between October 2012 to October 2014 at Dr. Susheela Tiwari Memorial Hospital, Haldwani, Uttarakhand. MATERIALS AND METHODS: This is a descriptive study of the patients with alleged isolated maxillofacial injury presenting in the Emergency, ENT & HNS OPD and Dentistry OPD of Dr. Susheela Tiwari Memorial Hospital, Haldwani. RESULTS: Most patients were in the age group 11-20 and 21-30 years with 20 and 36 patients respectively as consistent with the other studies. This study also showed a male preponderance accounting for 80.77% of the case load. The most common mode of injury in patients presented to the Emergency Department with faciomaxillary trauma was road traffic accidents, comprising 79.49% of cases. Assault and fall from height were the other causes, comprising 11. 54% and 8.97% respectively. CONCLUSIONS: Reliable epidemiological information on facio maxillary trauma is essential for decision making in the emergency, for identifying factors that increase the risk of injury and for providing targets for preventive measures. Multi detector CT is the investigation of choice for evaluation of faciomaxillary trauma. 3D images are useful for complex fractures involving the face. As there is no additional scanning or risk of radiation involved, 3D Virtual Reality Images and Multi Planar Rendering (MPR) is a valuable tool for radiologists for reporting/interpretation of faciomaxillary trauma.

Perception of professionals in the assessment of coronoid hyperplasia by computed tomography.

Coronoid Hyperplasia (CH) is a non-neoplastic and relatively rare enlargement of the coronoid process that may limit mandibular movement as a consequence of the close association between the hyperplastic coronoid process and the anterior region of the zygomatic bone. Computed tomography (CT) is extremely useful for the observation of this association and plays an important role in diagnosing and planning surgical treatment. Once the CT scan is performed, the data can be viewed in many different arrangements, including multiplanar (MPR) and 3D rendering, although the resolution of the latter may not be as good as that of the former. Our aim is to analyze the importance of and preference for multiplanar and 3D reconstruction images for diagnosing and interpreting Coronoid Hyperplasia (CH), by comparing the opinions of oral surgeons and oral radiologists who analyzed both temporomandibular joints (TMJ) in 20 patients. Three images of each TMJ comprised the set of scans (MPR, 3D reconstructions with maximum intercuspation and 3D reconstructions with maximum mouth opening). After each analysis, the members of the two groups answered a questionnaire about the usefulness of each examination and classified the association between the head of mandible and mandibular fossa. Hypomotility was present in 55.2%. Both groups stated that both MPR and 3D reconstructions, particularly the latter, were fundamental for diagnosing CH and that they would request them in order to interpret CH correctly. The examiners were found to differ significantly regarding their opinion of MPR; only radiologists considered MPR to be less elucidative for the diagnosis of CH.

MRI of the lumbar spine: comparison of 3D isotropic turbo spin-echo SPACE sequence versus conventional 2D sequences at 3.0 T

Three-dimensional (3D) fast spin-echo sequence with variable flip-angle refocusing pulse allows retrospective alignments of magnetic resonance imaging (MRI) in any desired plane. To compare isotropic 3D T2-weighted (T2W) turbo spin-echo sequence (TSE-SPACE) with standard two-dimensional (2D) T2W TSE imaging for evaluating lumbar spine pathology at 3.0 T MRI. Forty-two patients who had spine surgery for disk herniation and had 3.0 T spine MRI were included in this study. In addition to standard 2D T2W TSE imaging, sagittal 3D T2W TSE-SPACE was obtained to produce multiplanar (MPR) images. Each set of MR images from 3D T2W TSE and 2D TSE-SPACE were independently scored for the degree of lumbar neural foraminal stenosis, central spinal stenosis, and nerve compression by two reviewers. These scores were compared with operative findings and the sensitivities were evaluated by McNemar test. Inter-observer agreements and the correlation with symptoms laterality were assessed with kappa statistics. The 3D T2W TSE and 2D TSE-SPACE had similar sensitivity in detecting foraminal stenosis (78.9% versus 78.9% in 32 foramen levels), spinal stenosis (100% versus 100% in 42 spinal levels), and nerve compression (92.9% versus 81.8% in 59 spinal nerves). The inter-observer agreements (κ = 0.849 vs. 0.451 for foraminal stenosis, κ = 0.809 vs. 0.503 for spinal stenosis, and κ = 0.681 vs. 0.429 for nerve compression) and symptoms correlation (κ = 0.449 vs. κ = 0.242) were better in 3D TSE-SPACE compared to 2D TSE. 3D TSE-SPACE with oblique coronal MPR images demonstrated better inter-observer agreements compared to 3D TSE-SPACE without oblique coronal MPR images (κ = 0.930 vs. κ = 0.681). Isotropic 3D T2W TSE-SPACE at 3.0 T was comparable to 2D T2W TSE for detecting foraminal stenosis, central spinal stenosis, and nerve compression with better inter-observer agreements and symptom correlation.

Optic Strut and Para-clinoid Region - Assessment by Multi-detector Computed Tomography with Multiplanar and 3 Dimensional Reconstructions.

To evaluate thickness, location and orientation of optic strut and anterior clinoid process and variations in paraclinoid region, solely based on multidetector computed tomography (MDCT) images with multiplanar (MPR) and 3 dimensional (3D) reconstructions, among Indian population. Ninety five CT scans of head and paranasal sinuses patients were retrospectively evaluated with MPR and 3D reconstructions to assess optic strut thickness, angle and location, variations like pneumatisation, carotico-clinoid foramen and inter-clinoid osseous ridge. Mean optic strut thickness was 3.64mm (±0.64), optic strut angle was 42.67 (±6.16) degrees. Mean width and length of anterior clinoid process were 10.65mm (±0.79) and 11.20mm (±0.95) respectively. Optic strut attachment to sphenoid body was predominantly sulcal as in 52 cases (54.74%) and was most frequently attached to anterior 2/5(th) of anterior clinoid process, seen in 93 sides (48.95%). Pneumatisation of optic strut occurred in 23 sides. Carotico-clinoid foramen was observed in 42 cases (22.11%), complete foramen in 10 cases (5.26%), incomplete foramen in 24 cases (12.63%) and contact type in 8 cases (4.21%). Inter-clinoid osseous bridge was seen unilaterally in 4 cases. The study assesses morphometric features and anatomical variations of paraclinoid region using MDCT 3D and multiplanar reconstructions in Indian population.

Multi-detector computed tomography in evaluating locally aggressive and malignant bone tumours.

To evaluate the ability of Multi-Detector Computed Tomography in preoperative evaluation of locally aggressive and malignant bone tumours in correlation with histopathological findings. Twenty patients suspected of malignant bone tumours on the basis of their clinical profile were selected. Following a plain radiograph evaluation, all of them were subjected to CT scan examination. Multi Planar Reconstruction (MPR) was done in sagittal and coronal planes and also three-dimensional Volume Rendering (VR) and Maximum Intensity Projection (MIP) images were obtained. Of the 20 patients, 18 underwent surgery, and their histopathological findings were compared and correlated with MDCT findings. MDCT was 92.8% sensitive and 100% specific in determining the vascularity of the tumour and also can detect displacement/ encasement/ involvement of adjacent vessels. It has a sensitivity and specificity of 100% in determining cortical break, calcification and periosteal reaction. However, it is less sensitive in detecting joint involvement. Post contrast enhancement gives details of the extent of the soft tissue component. Although MRI is a preferred modality in preoperative evaluation of bone tumours, CT may be used an alternative in case of non-availability of MRI, which has faster acquisition time and better resolution. Using three dimensional MPR imaging, the location and extent of the tumour can be studied. It is also useful in determining cortical discontinuity, periosteal reaction, and calcification. By virtue of MIP and VR imaging, vascularity of the tumour and its relationship with the adjacent vasculature can be established. However, it is inferior to MRI in soft tissue characterization and has poor sensitivity in detecting marrow and joint involvement.

Post-therapeutic imaging findings

Any surgical approach modifies the normal anatomical and functional arrangement of the segmental spine which is aimed, therefore image interpretation cannot ignore a correct set of knowledge in the field of anatomy, pathophysiology, drug compliance, interventional radiology and surgery.Neuroradiological imaging has an important role before surgery to direct the surgeon or interventional radiologist during the operation, both in post-surgery, where imaging examination can rightly evaluate properties and effects of the treatment and can detect potential complications as infections, abscess, bleeding, exuberant scar, mobilization and rupture of devices.The available methods of imaging are the X-rays (XR) made at least in two projections, Computed Tomography (CT) with MPR (multiplanar) and VR (volume rendering) reconstruction, and Magnetic Resonance (MR), often performed before and after contrast media injection.Imaging assessment of spine after surgery is complex and depends upon several factors, including surgical procedures and disease for which it was performed; biomechanical of the underlying cortical and cancellous bone findings; conditions of muscles, intervertebral disk and ligaments; time since surgery procedures; duration and nature of the post-surgical syndrome.Depending upon several factors, one or a combination of complementary imaging modalities (X-rays, Computed Tomography, Magnetic Resonance) may be required to evaluate effectiveness of the treatment; to demonstrate any clinically relevant abnormality at the treated region and adjacent structures (complications such as inflammation, abscesses, bleeding and misplacement of the device); to assist the interventional radiologist or surgeon in deciding if is necessary intervene again, in which nature and in which vertebral level(s).

Proximal pulmonary vein stenosis detection in pediatric patients: value of multiplanar and 3-D VR imaging evaluation

One of the important benefits of using multidetector computed tomography (MDCT) is its capability to generate high-quality two-dimensional (2-D) multiplanar (MPR) and three-dimensional (3-D) images from volumetric and isotropic axial CT data. However, to the best of our knowledge, no results have been published on the potential diagnostic role of multiplanar and 3-D volume-rendered (VR) images in detecting pulmonary vein stenosis, a condition in which MDCT has recently assumed a role as the initial noninvasive imaging modality of choice. The purpose of this study was to compare diagnostic accuracy and interpretation time of axial, multiplanar and 3-D VR images for detection of proximal pulmonary vein stenosis in children, and to assess the potential added diagnostic value of multiplanar and 3-D VR images. We used our hospital information system to identify all consecutive children (< 18 years of age) with proximal pulmonary vein stenosis who had both a thoracic MDCT angiography study and a catheter-based conventional angiography within 2 months from June 2005 to February 2012. Two experienced pediatric radiologists independently reviewed each MDCT study for the presence of proximal pulmonary vein stenosis defined as ≥ 50% of luminal narrowing on axial, multiplanar and 3-D VR images. Final diagnosis was confirmed by angiographic findings. Diagnostic accuracy was compared using the z-test. Confidence level of diagnosis (scale 1-5, 5 = highest), perceived added diagnostic value (scale 1-5, 5 = highest), and interpretation time of multiplanar or 3-D VR images were compared using paired t-tests. Interobserver agreement was measured using the chance-corrected kappa coefficient. The final study population consisted of 28 children (15 boys and 13 girls; mean age: 5.2 months). Diagnostic accuracy based on 116 individual pulmonary veins for detection of proximal pulmonary vein stenosis was 72.4% (84 of 116) for axial MDCT images, 77.5% (90 of 116 cases) for multiplanar MDCT images, and 93% (108 of 116 cases) for 3-D VR images with significantly higher accuracy with 3-D VR compared to axial (z = 4.17, P < 0.001) and multiplanar (z = 3.34, P < 0.001) images. Confidence levels for detection of proximal pulmonary vein stenosis were significantly higher with 3-D VR images (mean level: 4.6) compared to axial MDCT images (mean level: 1.7) and multiplanar MDCT images (mean level: 2.0) (paired t-tests, P < 0.001). Thus, 3-D VR images (mean added diagnostic value: 4.7) were found to provide added diagnostic value for detecting proximal pulmonary vein stenosis (paired t-test, P < 0.001); however, multiplanar MDCT images did not provide added value (paired t-test, P = 0.89). Interpretation time was significantly longer and interobserver agreement was higher when using 3-D VR images than using axial MDCT images or MPR MDCT images for diagnosing proximal pulmonary vein stenosis (paired t-tests, P < 0.001). Use of 3-D VR images in the diagnosis of proximal pulmonary vein stenosis in children significantly increases accuracy, confidence level, added diagnostic value and interobserver agreement. Thus, the routine use of this technique should be encouraged despite its increased interpretation time.

MDCT Angiography Imaging Presentation of ALCAPA in Adults

Objective: To make a pictorial presentation of the anomalous origin of left coronary artery arising from the pulmonary artery (ALCAPA) appearances in adults on MDCT angiography. Methods: A retrospective evaluation was performed between 2005 and 2011 by ECG-gated coronary MDCT angiography. Total 8 patients included (9-51 years, mean age 29 years, 7 female). Image quality was evaluated firstly. Multi planar reformations (MPRs), maximum intensity projections (MIPs) and 3D volume-rendering techniques were used to evaluate image features. In addition, right and left coronary artery orifices were measured for each case. Results: Total 8/70,000 cases diagnosed ALCAPA by MDCT exam, all image qualities were acceptable. As the diagnose key point, all left coronary artery origin were clearly described, and indirect signs such as dilated and tortuous right/left arteries and collateral vessels between them, enlarged left ventricle were also well showed, the dilated degree of both the RCA and the LCA were marked with ages, the diameter of RCA for each case were a mild wider than that of left one. Other combined signs like papillary muscle calcification, bronchial arteries from aorta to the cardiac and coronary artery degeneration change were also included by MDCT angiography findings in a single data acquisition. No combined inter cardiac malformations in our group. Conclusion: ECG-gated MDCT an-giography plays an important role as a first-line modality in assessment of ALCAPA.

Utility of multi planar and 3D reconstruction for head injuries in the era of multi detector computed tomography

Utility of multi planar and 3D reconstruction for head injuries in the era of multi detector computed tomography

Evaluation of dehiscences using cone beam computed tomography

To validate the use of three-dimensional (3-D) surface rendering (SR) images to quantify the height of alveolar dehiscences. Twenty-four dehiscences were created on 9 incisors, 9 canines, and 6 premolars on 4 cadaver skulls. i-CAT cone beam computed tomography scans (CBCTs) were taken of each skull at .2 mm voxel size. Each dehiscence was quantified by 21 orthodontic residents using 3-D SR. The principal investigator (PI) also quantified each dehiscence using the 2-D multiplanar (MP) image and the 3-D SR image. Results of this study showed an average method error of the residents as a group to be 0.57 mm with an intraclass correlation (ICC) of 0.77%. Residents' method error ranged from 0.45 mm to 1.32 mm, and the ICC ranged from 0.201% to 0.857%. Systematic error was low at -0.01 mm for the direct measurement compared with the residents' average 3-D SR at 1365 density value (DV) measurement. The 3-D SR at 1365 DV images were compared with the MP and 3-D SR images at 1200 DV, and no significant differences in measurements and low systematic error were noted. The method error of the PI was 0.45 mm, 0.45 mm, and 0.41 mm for 3-D SR at 1365 DV, 3-D SR at 1200 DV, and 2-D MP, respectively. 3-D SR and 2D MRP can be used to measure dehiscences of the periodontium with similar levels of accuracy.

Comparative study on diagnosis of obstruction of bile duct by cholangiopancreatic multi planar reformations and curved planar reformatted image using 16-slice spiral CT of low field MRI and MRCP

Objective To evaluate the clinical application value of 16-slice spiral CT multi planar reformations(MPR) and curved planar reformations(CPR) in diagnosis of biliary obstructive disease. Methods 31 cases with obstruction of bile duct received 16-slice CT scanning and low field MRI, MRCP at the same time.All cases had pathology by operation or ERCP. All patients were reconstructed through multi planar reformations, curved reformatted technique and oblique anteroposterior axial location of muhiplanar reconstruction, and compared with MRCP,low field MRI, meanwhile also compared with operative pathology. Results There were no obvious difference for position identifying of obstruction of bile duct between cholangiopancreatic multi planar reformation, curved reformatted image using16-slice spiral CT, MRCP and low field MRI, the diagnosis in qualitation of obstruction, especially in diagnosing obstruction caused by gallstone, the former was better than the latter. Conclusion Using the cholangiopancreatic multi planar reformations curved reformatted method of 16 -slice spiral CT has very important value in the diagnosis of obstruction of bile duct. Key words: 16-slice spiral CT; Multi planar reformations; Curved planar reformations; Biliary obstructive disease

Olfactory bulb ventricles as a frequent finding—a myth or reality? Evaluation using high resolution 3 Tesla magnetic resonance imaging

Data on the prevalence of persistent olfactory bulb ventricles (OBV) in humans remain contradictory. The aim of this study was to investigate the hypothesis of large cystic-like OBVs filled with cerebrospinal fluid (CSF) as a frequent finding in magnetic resonance imaging (MRI). Fifty normosmic volunteers (25 men and 25 women, mean 40 years) underwent 3 Tesla MRI of the anterior skull base. Normal smell function was determined by testing of the odor threshold discrimination identification score using the Sniffin' Sticks test kit. The voxel size of the constructive interference in steady state (CISS) sequence was 0.4×0.4×0.4 mm (TR 12.18 ms, TE 6.09 ms) using a 12-channel head coil. Image quality was rated by three observers according to predefined criteria on an ordinal scale. Additionally, contrast-to-noise (CNR) and signal-to-noise (SNR) ratios were calculated. Quantitative signal intensity (SI) measurement of olfactory bulb (OB) structures and small Virchow-Robin spaces (VRS) was performed using multi planar reconstruction mode. Ninety-one OBs were eligible for evaluation. Image quality was rated as adequate in 55% and as excellent in 36% of cases. CNR and SNR calculations resulted in values of 21.59 and 19.06, respectively. Wilcoxon signed rank test revealed significant higher SI values for OB center compared to OB surface ( P<0.001) and to OB base ( P<0.001) but also significant lower SI values compared to small VRS ( P<0.001) in 94.5%. In 5.5%, SI measurement revealed signs for CSF-filled structures in the OB. High-resolution 3 Tesla MRI did not verify the hypothesis of large cystic CSF-filled OBVs as a frequent finding although evidence is growing that the hyperintense signal in the center of OBs might be associated with interstitial or finely dispersed CSF/fluid or with tiny, histologically detectable remnants of OBVs.

Accuracy of multidetector CT scans in staging of renal carcinoma

Objective The aim of this study is to determine the diagnostic accuracy of multidetector-row computed tomography (MDCT) compared to histopathological findings in tumor staging of renal cell carcinoma, with the focus on tumor size and stage, renal vein involvement, and peri-renal infiltration. Materials and methods In a retrospective study, a total of 98 consecutive patients with renal cell carcinoma were preoperatively assessed for tumor staging using multidetector-row CT. Triphasic CT imaging (i.e., noncontrast, arterial, and parenchymal phase) was performed using multidetector-row CT with the slice thickness of 5 mm and using multi planar reconstructions to define the tumor characteristics. A single blinded reader evaluated the CT scans independently who reviewed the scan on multi planar reconstructions. The results were then correlated with the histopathological results. Results A total of 98 renal cell carcinomas were proven on histopathology. There was a significant (p 0.05) difference in the mean maximum radiological and maximum pathological diameter of the tumor with radiological diameter being greater. Twenty seven tumors were down staged and only 1 was up staged. The specificity of CT for capsular invasion, nodal disease and adrenal involvement was 85, 82 and 98% respectively. The specificity was over 97% for tumor thrombus in renal vein and IVC. Conclusions The multi planar reconstruction capability of multidetector-row CT allowed good specificity in predicting renal vein, IVC involvement, capsular invasion and nodal disease.