Multiplanar Reformation Research Articles

Automated 3D Volumetry of the Pulmonary Arteries based on Magnetic Resonance Angiography Has Potential for Predicting Pulmonary Hypertension.

PurposeTo demonstrate feasibility of automated 3D volumetry of central pulmonary arteries based on magnetic resonance angiography (MRA), to assess pulmonary artery volumes in patients with pulmonary hypertension compared to healthy controls, and to investigate the potential of the technique for predicting pulmonary hypertension.MethodsMRA of pulmonary arteries was acquired at 1.5T in 20 patients with pulmonary arterial hypertension and 21 healthy normotensive controls. 3D model-based image analysis software was used for automated segmentation of main, right and left pulmonary arteries (MPA, RPA and LPA). Volumes indexed to vessel length and mean, minimum and maximum diameters along the entire vessel course were assessed and corrected for body surface area (BSA). For comparison, diameters were also manually measured on axial reconstructions and double oblique multiplanar reformations. Analyses were performed by two cardiovascular radiologists, and by one radiologist again after 6 months.ResultsMean volumes of MPA, RPA and LPA for patients/controls were 5508 ± 1236/3438 ± 749, 3522 ± 934/1664 ± 468 and 3093 ± 692/1812 ± 474 μl/(cm length x m2 BSA) (all p<0.001). Mean, minimum and maximum diameters along the entire vessel course were also significantly increased in patients compared to controls (all p<0.001). Intra- and interobserver agreement were excellent for both volume and diameter measurements using 3D segmentation (intraclass correlation coefficients 0.971–0.999, p<0.001). Area under the curve for predicting pulmonary hypertension using volume was 0.998 (95% confidence interval 0.990–1.0, p<0.001), compared to 0.967 using manually measured MPA diameter (95% confidence interval 0.910–1.0, p<0.001).ConclusionsAutomated MRA-based 3D volumetry of central pulmonary arteries is feasible and demonstrated significantly increased volumes and diameters in patients with pulmonary arterial hypertension compared to healthy controls. Pulmonary artery volume may serve as a superior predictor for pulmonary hypertension compared to manual measurements on axial images but verification in a larger study population is warranted.

Quantitative Assessment of Surgical Anatomy and Three-Dimensional Relationships in the Supralabyrinthine Space

Objective: To explore and quantify the surgically relevant anatomic relationships and three-dimensional (3D) morphology of the supralabyrinthine space, and enable a deeper, clearer understanding of its regional anatomy. Materials and Methods: 3D-DOCTOR software was used to create a 3D reconstruction of the axial CT images and multiplanar reformatting of 55 slices of temporal bone in 29 patients (17 males and 12 females), whose average age was 38.69 ± 17.81 years. The 3D relationships between the mutual complex structures were displayed graphically and measured. Results: The important structures within the temporal bone were displayed in detail. 3D relationships between the structures in the temporal bone, such as the ossicles, facial nerves, labyrinth, and skull base, were quantified. Conclusion: Quantification of surgically relevant anatomic relationships and the morphology of the supralabyrinthine space in three dimensions are very helpful in surgical dissection.

Lymph nodes metastasis of gastric cancer: Measurement with multidetector CT oblique multiplanar reformation-correlation with histopathologic results.

The aim of this study was to retrospectively evaluate the ability of multidetector computed tomography (MDCT) oblique multiplanar reformation (MPR) for differentiating metastatic lymph nodes (LNs) in patients with gastric cancer.Seventy-nine patients with gastric cancer underwent preoperative computed tomography (CT). One-to-one correlation of LN was made between CT oblique multiplanar reformation and histopathologic slides. Long diameters, short diameters, and short-to-long axis ratios of LNs were evaluated to differentiate metastasis.Short diameters of nodes performed better for diagnosing metastasis than long diameters and short-to-long ratios. Sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve of short diameter were 57.8%, 74.7%, 68.2%, and 0.713, respectively. With different thresholds of short diameters of nodes (No. 8 group >6 mm and other groups >4 mm), total sensitivity, specificity, and accuracy can reach 57.2%, 79.0%, and 70.3%, respectively.MDCT oblique MPR images have certain reference value to distinguish metastasis of LNs in gastric cancer. The diagnostic power for LN metastasis of gastric cancer can be improved by using different threshold for No. 8 group LNs and other groups.

Three-Dimensional Isotropic Fat-Suppressed Proton Density-Weighted MRI at 3 Tesla Using a T/R-Coil Can Replace Multiple Plane Two-Dimensional Sequences in Knee Imaging

To evaluate whether a 3 D proton density-weighted fat-suppressed sequence (PDwFS) of the knee is able to replace multiplanar 2D-PDwFS. 52 patients (26 men, mean age: 41.9 ± 14.5years) underwent magnetic resonance imaging (MRI) of the knee at 3.0 Tesla using a T/R-coil. The imaging protocol included 3 planes of 2D-PDwFS (acquisition time (AT): 6:40 min; voxel sizes: 0.40 - 0.63 × 0.44 - 0.89 × 3mm³) and a 3D-PDwFS (AT: 6:31 min; voxel size: 0.63 × 0.68 × 0.63mm³). Homogeneity of fat suppression (HFS), artifacts, and image sharpness (IS) were evaluated on a 5-point scale (5[excellent] - 1[non-diagnostic]). The sum served as a measure for the overall image quality (OIQ). Contrast ratios (CR) compared to popliteal muscle were calculated for the meniscus (MEN), anterior (ACL) and posterior cruciate ligaments (PCL). In 13patients who underwent arthroscopic knee surgery, two radiologists evaluated the presence of meniscal, ligamental and cartilage lesions to estimate the sensitivity and specificity of lesion detection. The CR was higher in theACL, PCL and MEN in 3D- PDwFS compared to 2D-PDwFS (p < 0.01 for ACL and PCL; p = 0.07 for MEN). Compared to 2 D images, the OIQ was rated higher in 3D-PDwFS images (p < 0.01) due to fewer artifacts and HFS despite the lower IS (p < 0.01). The sensitivity and specificity of lesion detection in 3D- and 2D-PDwFS were similar. Compared to standard multiplanar 2D-PDwFS knee imaging, isotropic high spatial resolution 3D-PDwFS of the knee at 3.0 T can be acquired with high image quality in a reasonable scan time. Multiplanar reformations in arbitrary planes may serve as an additional benefit of 3D-PDwFS. • 3D-PDwFS of the knee is acquired with high image quality• 3D-PDwFS can be achieved in only one measurement with a reasonable scan time• 3D-PDwFS with the advantage of multiplanar reformation may replace 2D-PD-weighted knee MRI Citation Format: • Homsi R, Gieseke J, Luetkens JA et al. Three-Dimensional Isotropic Fat-Suppressed Proton Density-Weighted MRI at 3 Tesla Using a T/R-Coil Can Replace Multiple Plane Two-Dimensional Sequences in Knee Imaging. Fortschr Röntgenstr 2016; 188: 949 - 956.

Influence of model based iterative reconstruction algorithm on image quality of multiplanar reformations in reduced dose chest CT.

BackgroundModel-based iterative reconstruction (MBIR) reduces image noise and improves image quality (IQ) but its influence on post-processing tools including maximal intensity projection (MIP) and minimal intensity projection (mIP) remains unknown.PurposeTo evaluate the influence on IQ of MBIR on native, mIP, MIP axial and coronal reformats of reduced dose computed tomography (RD-CT) chest acquisition.Material and MethodsRaw data of 50 patients, who underwent a standard dose CT (SD-CT) and a follow-up RD-CT with a CT dose index (CTDI) of 2–3 mGy, were reconstructed by MBIR and FBP. Native slices, 4-mm-thick MIP, and 3-mm-thick mIP axial and coronal reformats were generated. The relative IQ, subjective IQ, image noise, and number of artifacts were determined in order to compare different reconstructions of RD-CT with reference SD-CT.ResultsThe lowest noise was observed with MBIR. RD-CT reconstructed by MBIR exhibited the best relative and subjective IQ on coronal view regardless of the post-processing tool. MBIR generated the lowest rate of artefacts on coronal mIP/MIP reformats and the highest one on axial reformats, mainly represented by distortions and stairsteps artifacts.ConclusionThe MBIR algorithm reduces image noise but generates more artifacts than FBP on axial mIP and MIP reformats of RD-CT. Conversely, it significantly improves IQ on coronal views, without increasing artifacts, regardless of the post-processing technique.

Audit of CT reporting standards in cases of intracerebral haemorrhage at a comprehensive stroke centre in Australia.

Multiple CT-derived biomarkers that are predictive of intracerebral haemorrhage (ICH) growth and outcome have been described in the literature, but the extent to which these appear in imaging reports of ICH is unknown. The aim of this retrospective process audit was to determine which of the known predictors of ICH outcome was recorded in reports of the disease, with a view to providing reporting recommendations, as appropriate. We examined the initial CT report of patients diagnosed with ICH presenting to a metropolitan comprehensive stroke centre and meeting inclusion criteria during the audit period between 1 March 2013 and 28 February 2014. Each report was assessed for the inclusion of the following ICH characteristics: the number of measurement dimensions; volume; location; hydrocephalus; shape; density; 'CTA spot sign' (where CTA was performed). A total of 100 patients met audit inclusion criteria. At least one ICH dimension was recorded in 90% of reports; however, 39% did not include the measurements in three dimensions and volume was reported in just 6%. No ICH dimension was recorded in 10% of reports. With the exception of density and shape, reporting of other CT features exceeded 95%. Where CTA was performed (58%), 14 (24%) of 58 reported the 'CTA spot sign' status. In this audit, volume was the most under-reported of the established ICH characteristics predictive of ICH outcome. Readily calculated from multiplanar reformats using the ABC/2 technique, the routine reporting of ICH volume is recommended. More reporting attention to ICH density heterogeneity and shape irregularity is encouraged, given their emerging importance. Where acute CTA is performed, the presence of any dynamic haemorrhage (CTA spot sign) should be reported.

Multislice computer tomography in detection of pseudocapsule of renal cell carcinoma

In order to evaluate the diagnostic efficiency of MDCT with bolus contrast enhancement in the visualization of renal cancer pseudocapsule a retrospective study, included 74 patients with histologically confirmed renal-cell cancer, was performed. Images were acquired in native, arterial, portal and nephrographic - excretory phase on a 64-detector CT scanner. The accuracy of MDCT in detecting pseudocapsule was determined by comparison with histological findings. Native axial images and multiplanar reformations were analyzed. According to the results of the study there was obtained high diagnostic efficiency of MDCT in detecting of the tumor pseudocapsule, that allows to use this method for the preoperative evaluation, assessment of the possibility ofperforming organ-saving surgery.

Diagnostic Utility of Three-Dimensional Rotational Angiography in Congenital Cardiac Catheterization.

We evaluated the diagnostic utility of the three modalities of three-dimensional rotational angiography (3DRA): rotational angiography (RA), multiplanar reformat (MPR) and three-dimensional angiographic reconstruction (3D-R) in pediatric cardiac catheterization. The 3DRA studies were classified by anatomy of interest based on our injection protocol: pulmonary arteries (PA), aorta, cavopulmonary connection (CPC), and others. Retrospective review of 3DRA images by two reviewers for each modality was conducted with grading as inferior, similar, or superior in comparison with the diagnostic quality of fixed-plane angiography (FPA). The percentages of grades for each modality were averaged. Weighted kappa statistic was used to evaluate inter-rater reliability. In total, 114 3DRA studies were performed on 87 patients between August 2010 and March 2012. Median age was 2.7years (1day-48.4years) and median weight 12.1kg (3.6-106.5kg). For RA: 79.4% of the studies were of diagnostic quality and 52.2% were superior; 3D-R: 82% were of diagnostic quality and 65.8% were superior; and MPR: 83.5% were of diagnostic quality and 63% were superior. Overall 3DRA technologies (RA, 3D-R, MPR) were of diagnostic quality or better in 111/114 (97.4%) studies and 103/114 (90.4%) were judged superior. Most common reasons for inferior grading were limited opacification and metallic artifact. In pediatric cardiac catheterization, 3DRA imaging was of diagnostic quality and frequently provided additional clinically relevant data when compared to FPA.

Imaging of Pericardiophrenic Bundles Using Multislice Spiral Computed Tomography for Phrenic Nerve Anatomy.

Phrenic nerve injury and diaphragmatic stimulation are common complications following arrhythmia ablation and pacing therapies. Preoperative comprehension of phrenic nerve anatomy via non-invasive CT imaging may help to minimize the electrophysiological procedure-related complications. Coronary CT angiography data of 121 consecutive patients were collected. Imaging of left and right pericardiophrenic bundles was performed with volume rendering and multi-planar reformation techniques. The shortest spatial distances between phrenic nerves and key electrophysiology-related structures were determined. The frequencies of the shortest distances ≤5 mm, >5 mm and direct contact between phrenic nerves and adjacent structures were calculated. Left and right pericardiophrenic bundles were identified in 86.8% and 51.2% of the patients, respectively. The right phrenic nerve was <5 mm from right superior and inferior pulmonary veins in 92.0% and 3.2% of the patients, respectively. The percentage of right phrenic nerve, <5 mm from right atrium, superior caval vein, and superior caval vein-right atrium junction was 87.1%, 100%, and 62.9%, respectively. Left phrenic nerve was <5 mm from left atrial appendage, great cardiac vein, anterior and posterior interventricular veins, and left ventricular posterior veins in 81.9%, 1.0%, 39.1%, 28.6%, and 91.4% of the patients, respectively. Merely 0.06% left phrenic nerve had a distance <5 mm with left superior pulmonary vein, and none left phrenic nerve showed a distance <5 mm with left inferior pulmonary vein. One-stop enhanced CT scanning enabled detection of phrenic nerve anatomy, which might facilitate avoidance of the phrenic nerve-related complications in interventional electrophysiology.

Nontraumatic Subclavian Artery Abnormalities: Spectrum of MDCT Findings.

The subclavian arteries (SCAs) may exhibit a wide spectrum of nontraumatic pathologic conditions ranging from common diseases, such as atherosclerosis, to vascular emergencies that are associated with a high morbidity and high mortality, such as type A aortic dissection and acute arterial thrombosis. MDCT angiography is an excellent modality to diagnose pathologic conditions of the SCAs. Optimization of CT acquisition protocols and interactive interpretation with 2D multiplanar reformatting and 3D rendering techniques are critical for diagnostic accuracy.

Agenesis of Inferior Vena Cava with Cavernous Transformation and Hypoplastic Infrarenal Part of IVC, Rare Congenital Vascular Anomalies: A Case Series

Congenital vascular anomalies are although rare but may cause serious complications. Vascular pathologies are best demonstrated by contrast enhanced computed tomography, with the advent of multidetector computed tomography and applying multiplanar reformation techniques. However, ultrasound color Doppler and catheter angiography are accessory imaging modalities utilized to rule out vascular anomalies. We present here a case series of 2 patients aged 19 years and 54 years, diagnosed with congenital vascular anomalies (agenesis of inferior vena cava and hypo plastic infra renal segment of inferior vena cava). The development of inferior vena cava (IVC) includes early embryogenesis stages including formation, confluence and involution of three primary longitudinal venous systems. Agenesis of inferior vena cava or hypoplasia of segment of inferior vena cava leads to formation of collaterals to maintain the venous flow. Contrast enhanced computed tomography with multiplanar reformation provides ulterior spatial and contrast resolution in cases of recognized vascular abnormalities. Inferior vena cava obstruction due to thrombosis or congenital vascular anomaly leads to extensive collateralization accompanied by varicose veins. In our case series, we found contrast enhanced computed tomography as an ulterior modality in setting ultimate diagnosis with accuracy and maximum detail.

Posteromedial subtalar coalitions: prevalence and associated morphological alterations of the sustentaculum tali.

A variant form of subtalar coalition isolated to the posterior sustentaculum has been previously described, though its prevalence is not known and its relationship to the middle facet has not been characterized. To determine the prevalence and morphological alterations of isolated posteromedial subtalar coalitions. Computed tomography (CT) images of the foot or ankle performed from 2004 to 2012 were reviewed and 97 patients (mean age: 13.3+/-2.9years; range: 9-19years) with subtalar coalition were identified. In 41 (42%) of these, the condition was bilateral, yielding a total of 138 subtalar coalitions. In the 33 patients where CT demonstrated isolated posteromedial subtalar coalitions, multiplanar reformats along the long axis of the sustentaculum tali were generated, from which the anteroposterior dimensions of the sustentaculum tali and middle facet were measured. Posterior sustentaculum measurements defining the posterior extension of the sustentaculum beyond the middle facet were directly measured by two radiologists. Ratios of middle facet to posterior sustentaculum measurements were calculated. Thirty-three patients undergoing CT for ankle fracture served as controls. Ninety-seven of 138 coalitions (70.2%) affected the middle facet and 2/138 (1.4%) involved the posterior facet. There were 39 (28.2%) posteromedial subtalar coalitions in 33 patients. Mean AP measurements of the middle facet and posterior sustentaculum in patients with posteromedial subtalar coalitions were 12.6mm and 18.2mm, respectively, compared to 16.6mm and 9.2mm in controls (P<0.001). Mean middle facet/posterior sustenaculum (MF/PS) ratios were 0.74 for posteromedial subtalar coalitions vs. 1.92 for controls (P<0.001). Posteromedial subtalar coalitions comprise more than one-quarter of subtalar coalitions, and are associated with an intact, but shorter, middle facet and longer sustentaculum tali. This observation may aid in accurate diagnosis and management of this relatively common disorder.

An RCT study on the feasibility of anterior transpedicular screw fixation in the cervicothoracic junction

We evaluated the trajectory and the entry points of anterior transpedicular screws (ATPS) in the cervicothoracic junction (CTJ). This study aimed at investigating the feasibility of ATPS fixation in the CTJ. Application of an ATPS in the lower cervical spine has been reported; however, there were no reports exploring the feasibility of anterior transpedicular screw fixation in the CTJ. CT scans were performed in 50 cases and multiplanar reformation was used to measure the related parameters on pedicle axis view at C6-T2. Transverse pedicle angle, outer pedicle width, pedicle axis length, distance transverse intersection point (DtIP), sagittal pedicle angle, anterior vertebral body height, outer pedicle height, and distance sagittal intersection point (DsIP) were measured. The prozone of CTJ was divided into three different regions, which were named as the "manubrium region", the region "above" and "below" the manubrium. The distribution of the trajectory of sagittal pedicle axes was recorded in the three regions and the related data were statistically analyzed. There was no statistical difference in gender (P>0.05). The transverse pedicle angle decreased from C6 (46.77°±2.72°) to T2 (20.62°±5.04°). DtIP increased from C6 to T2. DsIP was an average of 7.17mm. The sagittal pedicle axis lines of the C6 and C7 were located in the region above the manubrium. T1 was mainly in the manubrium region followed by the region above the manubrium. T2 was mainly located in the manubrium region followed by the region below the manubrium. Implantation of ATPS at C6, C7, and some T1 is feasible through the low anterior cervical approach, while it is almost impossible to approach T2 that way.

Extracranial internal carotid artery: anatomical variations in asymptomatic patients

The anatomical variations of internal carotid artery (ICA) are mostly asymptomatic, thus being disregarded and only incidentally diagnosed, with very few symptomatic patients. The awareness of these anomalies is crucial to solve the differential with other neck lesions, preventing accidental injuries during neck surgery. Therefore, the aim of our study is to estimate the prevalence of ICA anomalies, using magnetic resonance angiography (MRA) and computed tomography angiography (CTA). 253 patients underwent head and neck MRA and CTA examinations, with multiplanar and volumetric reformations. For each set of images, the following items were investigated: origin, development, course, persistence of embryonic vessels and anomalous origin of collateral branches. In our series, ICA arose from the bifurcation of the common carotid artery at the level of: C4 in 303 hemi-necks (59.9%); C3 in 98 hemi-necks (19.3%); C5 in 57 hemi-necks (11.3%); C2 in 48 hemi-necks (9.5%). ICA kinking and/or coiling was found in 105 hemi-necks, and location variation of ICA (reversed-type) in two hemi-necks. In just one case the origin of the ascending pharyngeal artery was from ICA (0.2%), while an anomalous persistence of the proatlantal artery was noticed in three cases (0.6%). CTA and MRA showed similar accuracy in detecting ICA anomalies.

Three-dimensional volumetric MRI with isotropic resolution: improved speed of acquisition, spatial resolution and assessment of lesion conspicuity in patients with recurrent soft tissue sarcoma

To assess the acquisition speed, lesion conspicuity, and inter-observer agreement associated with volumetric T(1)-weighted MR sequences with isotropic resolution for detecting recurrent soft-tissue sarcoma (STS). Fifteen subjects with histologically proven recurrent STS underwent MRI, including axial and coronal T(1)-weighted spin echo (T(1)-WSE) (5-mm slice thickness) and coronal 3D volumetric T(1)-weighted (fat-suppressed, volume-interpolated, breath-hold examination; repetition time/echo time, 3.7/1.4 ms; flip angle, 9.5°; 1-mm slice thickness) sequences before and after intravenous contrast administration. Subtraction imaging and multiplanar reformations (MPRs) were performed. Acquisition times for T(1)-WSE in two planes and 3D sequences were reported. Two radiologists reviewed images for quality (>50 % artifacts, 25-50 % artifacts, <25 % artifacts, and no substantial artifacts), lesion conspicuity, contrast-to-noise ratio (CNR(muscle)), recurrence size, and recurrence-to-joint distance. Descriptive and intraclass correlation (ICC) statistics are given. Mean acquisition times were significantly less for 3D imaging compared with 2-plane T(1)-WSE (183.6 vs 342.6 s; P = 0.012). Image quality was rated as having no substantial artifacts in 13/15 and <25 % artifacts in 2/15. Lesion conspicuity was significantly improved for subtracted versus unsubtracted images (CNR(muscle), 100 ± 138 vs 181 ± 199; P = 0.05). Mean recurrent lesion size was 2.5 cm (range, 0.7-5.7 cm), and measurements on 3D sequences offered excellent interobserver agreement (ICC, 0.98 for lesion size and 0.96 for recurrence-to-joint distance with MPR views). Three-dimensional volumetric sequences offer faster acquisition times, higher spatial resolution, and MPR capability compared with 2D T(1)-WSE for postcontrast imaging. Subtraction imaging provides higher lesion conspicuity for detecting recurrent STS in skeletal muscle, with excellent interobserver agreement between readers.

MR neurographic orthopantomogram: Ultrashort echo-time imaging of mandibular bone and teeth complemented with high-resolution morphological and functional MR neurography.

Panoramical radiographs or cone-beam computed tomography (CT) are the standard-of-care in dental imaging to assess teeth, mandible, and mandibular canal pathologies, but do not allow assessment of the inferior alveolar nerve itself nor of its branches. We propose a new technique for "MR neurographic orthopantomograms" exploiting ultrashort echo-time (UTE) imaging of bone and teeth complemented with high-resolution morphological and functional MR neurography. The Institutional Review Board approved the study in 10 healthy volunteers. Imaging of the subjects mandibles at 3.0T (Magnetom Skyra, Siemens-Healthcare) using a 64-channel head coil with isotropic spatial resolution for subsequent multiplanar reformatting, was performed. Bone images were acquired using a 3D PETRA sequence (TE, 0.07 msec). Morphological nerve imaging was performed using a dedicated 3D PSIF and 3D SPACE STIR sequence. Functional MR neurography was accomplished using a new accelerated diffusion-tensor-imaging (DTI) prototype sequence (2D SMS-accelerated RESOLVE). Qualitative and quantitative image analysis was performed and descriptive statistics are provided. Image acquisition and subsequent postprocessing into the MR neurographic orthopantomogram by overlay of morphological and functional images were feasible in all 10 volunteers without artifacts. All mandibular bones and mandibular nerves were assessable and considered normal. Fiber tractography with quantitative evaluation of physiological diffusion properties of mandibular nerves yielded the following mean ± SD values: fractional anisotropy, 0.43 ± 0.07; mean diffusivity (mm(2) /s), 0.0014 ± 0.0002; axial diffusivity, 0.0020 ± 0.0002, and radial diffusivity, 0.0011 ± 0.0001. The proposed technique of MR neurographic orthopantomogram exploiting UTE imaging complemented with high-resolution morphological and functional MR neurography was feasible and allowed comprehensive assessment of osseous texture and neural microarchitecture in a single examination. J. Magn. Reson. Imaging 2016;44:393-400.

Role of multidetector CT (64 Slice) in the evaluation of living potential donors for renal transplantation

Background: Renal transplantation is the definitive therapy for the end stage renal disease. This study was undertaken to assess the role of MDCT (64-slice) in the preoperative evaluation of living potential renal transplantation donors for transplantation. Methods: This prospective one year study included 31 potential living renal donors aged between 22-69 years, sent to the department of radio diagnosis for MDCT using 64-slice CT scanner. Nonionic IV contrast material (130-150mL) was given at a rate of 4-5 mL/sec. Arterial images were acquired by smart prep technique followed by venous phase after 20-25 second delay. Finally, excretory phase was taken after 8 minutes from the start of injection. KV of 120, mAs of 250-790 and collimations of 0.625 mm were used. CT data included determination of renal size, assessment of renal parenchyma (cyst, calculus, mass etc); depiction of renal arterial, venous, and urographic anatomy and identification of important vascular variants. Image processing included three-dimensional volume renderings, maximum intensity projections and multiplanar reformations. Results: We identified surgically important vascular variants and renal parenchymal abnormalities. Of the 31 subjects evaluated, 4(12.9%) subjects were excluded on the basis of CT findings, due to vascular variants in 3 cases (9.7%) subjects and bilateral microliths in 1(3.2%). The surgical decision of right nephrectomy was taken in 2 (6.4%) cases due to complex vascular anatomy on left side depicted on CT. Conclusions: Triple phase MDCT provided comprehensive parenchymal and vascular preoperative evaluation of potential living donors for renal transplantation, thus had an impact in deciding the suitability of donor and side of kidney to be harvested for nephrectomy. It provided a road map to the surgeons which helped them in surgical planning to reduce surgical complications.

Evaluation of renal vascular anatomy in live renal donors: Role of multi detector computed tomography.

Background:Evaluation of renal vascular variations is important in renal donors to avoid vascular complications during surgery. Venous variations, mainly resulting from the errors of the embryological development, are frequently observed.Aim:This retrospective cross-sectional study aimed to investigate the renal vascular variants with multidetector computed tomography (MDCT) angiography to provide valuable information for surgery and its correlations with surgical findings.Materials and Methods:A total of 200 patients underwent MDCT angiography as a routine work up for live renal donors. The number, course, and drainage patterns of the renal veins were retrospectively observed from the scans. Anomalies of renal veins and inferior vena cava (IVC) were recorded and classified. Multiplanar reformations (MPRs), maximum intensity projections, and volume rendering were used for analysis. The results obtained were correlated surgically.Results:In the present study, out of 200 healthy donors, the standard pattern of drainage of renal veins was observed in only 67% of donors on the right side and 92% of donors on the left side. Supernumerary renal veins in the form of dual and triple renal veins were seen on the right side in about 32.5% of donors (dual right renal veins in 30.5% cases and triple right renal veins in 2.5% cases). Variations on the left side were classified into four groups: supernumerary, retro-aortic, circumaortic, and plexiform left renal veins in 1%, 2.5%, 4%, 0.5%, cases respectively.Conclusions:Developmental variations in renal veins can be easily detected on computed tomography scan, which can go unnoticed and can pose a fatal threat during major surgeries such as donor nephrectomies in otherwise healthy donors if undiagnosed.

Introducing Cinematic Rendering: A Novel Technique for Post-Processing Medical Imaging Data

Since the 1980s, various techniques have been used in the field of medicine for the post-processing of medical imaging data from computed tomography (CT) and magnetic resonance (MR). They include multiplanar reformations (MPR), maximum intensity projection (MIP) and Volume Rendering (VR). This paper presents the prototype of a new means of post-processing radiological examinations such as CT and MR, a technique that, for the first time, provides photorealistic visualizations of the human body. This new procedure was inspired by the quality of images achieved by animation software such as programs used in the entertainment industry, particularly to produce animated films. Thus, the name: Cinematic Rendering. It is already foreseeable that this new method of depiction will quickly be incorporated into the set of instruments employed in socalled virtual anatomy (teaching anatomy through the use of radiological depictions of the human body via X-ray, CT and MR in addition to the use of computer animation programs designed especially for human anatomy). Its potential for medical applications will have to be evaluated by future scientific investigations.

Quantitative Gross and CT measurements of Cadaveric Cervical Vertebrae (C3 - C6) as Guidelines for the Lateral mass screw fixation.

Lateral mass screw fixation is the treatment of choice for posterior cervical stabilization. Long or misdirected screws carry a risk of injury to spinal nerve roots or vertebral artery. This study was aimed to assess the gross anatomic and CT measurements of typical cervical vertebrae for the selection of lateral mass screws. Dimensions of the articular pillars were measured on 1) Dry cervical vertebrae with Vernier calipers and 2) Multiplanar reformations of CT scans of the same vertebrae with Viewer software package. The data was statistically evaluated. The transverse diameter of the articular pillars with Vernier calipers varied from 6.0 to 15.4 mm (mean=10.5 mm ± 1.5) and on CT scans ranged from 8.2 - 16.1 mm (mean=11.6 mm ± 1.4). The antero-posterior diameter, an estimate of the screw length by Roy-Camille technique varied from 3.9 to 12.7 mm (mean=8.6 mm ± 1.6) by Vernier calipers and from 6.4 to 13.3 mm (mean=9.1 ± 1.2) on CT scans. The oblique AP diameter, an estimate of screw length by Magerl method varied from 10.8 to 20.3 mm (mean=14.9 mm ± 1.8) by Vernier calipers and from 11.4 to 19.3 mm (mean=14.5 mm ± 1.7) on CT. The CT measurements for height, transverse and AP diameter of the articular pillars were 0.5 - 1.0 mm larger than dimensions by Vernier calipers. No statistically significant difference was observed between the caliper and CT measurements for the oblique AP diameter. CT measurements of the articular pillars may slightly overestimate the desired screw length selected by spine surgeons when compared to actual anatomy. Although means of the articular pillars correspond to the screw lengths used, substantial number of observations below 10 mm for Roy-Camille trajectory and below 14 mm for Magerl trajectory requires careful preoperative planning and intra-operative confirmation to avoid long/misdirected lateral mass screws.