Multiplanar Reformatted Images Research Articles

Prevalence of Femoroacetabular Impingement Morphology in Asymptomatic Adolescents.

Femoroacetabular impingement (FAI) can lead to acetabular chondrolabral damage and has been theorized as a causative factor in the development of osteoarthritis. The pathogenesis of FAI is unknown. The purpose of this study was to determine the prevalence of FAI morphology in asymptomatic adolescents. We identified children 10 to 18 years of age who had undergone a pelvic CT between 2007 and 2012. Exclusion criteria included hip pain, any hip pathology, bone tumor, long-term steroid use, history of chemotherapy or radiation therapy, nonambulatory status, neuromuscular disorder, chromosomal abnormality, and metabolic bone disease. Multiplanar reformatted images were created from axial images to calculate α angles and lateral center-edge angles (LCEA). Cam morphology was defined as an α-angle ≥55 degrees and pincer morphology as a LCEA≥40 degrees. We analyzed 558 patients (1116 hips). There were 276 males and 282 females. The average age was 14.4 years (range, 10.0 to 18.2 y). The mean α-angle was 47.9 degrees (range, 25.7 to 78 degrees) and the mean LCEA was 34.4 degrees (range, 3.9 to 58.6 degrees). Males had a significantly higher mean α-angle (49.7 vs. 46.0 degrees) (P<0.0005) and females had a significantly higher mean LCEA (35.7 vs. 33.0 degrees) (P<0.0005). Ninety-four adolescents (16.8%) had an α-angle ≥55 degrees. Cam morphology was significantly more common in males (23.9% vs. 9.9%) (P<0.001). A total of 181 adolescents (32.4%) had a LCEA≥40 degrees. Pincer morphology was equally common in males and females (29.7% vs. 35.1%) (P=0.17). Thirty-four adolescents (6.1%) had mixed morphologies. Mixed morphologies were found in 21 males (7.6%) and 13 females (4.6%) (P=0.19). The prevalence of pincer morphology increased significantly with increased age in males (P<0.001). The prevalence of cam-type FAI morphology in asymptomatic adolescents is similar to the reported prevalence in asymptomatic adults. Pincer morphology may be more common than cam morphology in adolescents. Cam morphology is more prevalent in males, whereas pincer and mixed morphologies are equally prevalent in both sexes. Level III-diagnostic.

Diagnostic performance of multi-slice computed tomography using 2D and 3D images in the assessment of Le Fort fractures

ObjectiveThe aim of this study was to assess the role of multislice computed tomography (MSCT) using 2D and 3D images in evaluation of different types of Le Fort fractures. Subjects and methods30 cases referred from the Emergency unit in Zagazig University Hospital were included in this study, based on clinical evidence of facial trauma, they underwent multislice computed tomography (MSCT) examination and were shown to be positive for pterygoid fractures.All patients subjected to non contrast MSCT in axial cuts. Multiplanar reformatted (MPR) images were acquired using the machine software in sagittal and coronal planes. Finally images were transferred to a workstation for reconstruction of 3D images. ResultsSensitivity of multislice computed tomography (MSCT) in detecting compound Le Fort fractures for radiologists A, B and C was 94.4%, 66.7% and 100% respectively. Sensitivity of MSCT in detecting isolated Le Fort fractures for radiologists A, B and C was 100%. The difference between radiologists A, B and C in detecting Le Fort fractures types was insignificant. Good agreement between radiologists A, B, C and intraoperative findings. ConclusionBoth 2D-CT and 3D-CT are the best methods in imaging of Le Fort fractures.

Optic Nerve Canal Relation to Posterior Paranasal Sinuses in Indian Ethnics: Review and Objective Classification.

Posterior paranasal sinuses consisting of posterior ethmoid and sphenoid sinuses show varying pneumatization and relationship to Optic Nerve Canal (ONC). Most commonly ONC is superolateral to sphenoid sinus, however varied protrusion of ONC into the sinuses may occur. Rarely it may pass completely through the sinus. Optic Nerve (ON) is covered by a thin bony layer or by periosteum and sinus mucosa without bone. Extensive pneumatization of sphenoid sinus and bony dehiscence predisposes to ON injury. The posterior ethmoid cell namely the Onodi cell is of great surgical importance when the ON is along its lateral wall and surrounds the nerve. These varied relations imply that a detailed knowledge of the intimate relationship of ONC with the posterior paranasal sinuses is necessary to avoid unintentional complications during the surgeries involving the ONC region. To assess relationship of ONC to the posterior paranasal sinuses in Indian Ethnic study group. Retrospective review of 100 paranasal sinus Computed Tomography (CT) scans were done using 64 row Multi Detector Computed Tomography (MDCT). Multiplanar reformation images were assessed for ONC relation to posterior ethmoid and sphenoid sinuses, wall dehiscence, and Pneumatization of Anterior Clinoid Process (PACP). 200 optic nerve canals were assessed and grouped into four types based on the modification of Delano et al., classification. The most common OCN was Type-1 (60%), followed by Type-2 (15%), Type-3 (14%) and Type-4 (11%). Dehiscence was seen in 35(17.5%) mostly in Type-3 canals. PACP was seen in 30 (15%). Knowledge of ON relationship to posterior paranasal sinuses will reduce the devastating complications during sinus surgeries. Our modified ONC classification is based on the bony canal morphology and the degree of protrusion into sinuses. As with other reported studies worldwide, Type-1 ONC is the commonest among the Indians also. Type-2 and 3 ONC with sinus wall dehiscence and PACP are the most important anatomical variations which may potentially predispose to risk of surgical injury to the optic nerves.

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.

CT manifestations of small bowel ischemia due to impaired venous drainage-with a correlation of pathologic findings.

Acute abdominal pain may result from a wide variety of medical and surgical diseases. One of these diseases is small bowel ischemia, which may result in a catastrophic outcome if not recognized and treated promptly. Computed tomography (CT) by its faster image acquisition, thinner collimation, high resolution, and multiplanar reformatted images has become the most important imaging modality in evaluating the acute abdominal conditions. In this article, the author presents a description of the histology of the small bowel, pathophysiology of small bowel change, and a correlation of the pathologic and CT findings of the small bowel injuries due to impaired venous drainage. A convincing correlation of the microscopic mucosal condition with the enhancement pattern of the thickened small bowel wall on CT is useful in definitely describing the mucosal viability.

Feasibility for Measuring Transverse Area Ratios and Asymmetry of Lumbosacral Region Paraspinal Muscles in Working Dogs Using Computed Tomography.

Describe computed tomographic (CT) anatomy of canine lumbosacral (LS) paraspinal muscles, a method for measuring paraspinal muscle transverse area ratios and asymmetry using CT, and application of this method in a small sample of working dogs with versus without LS pain. Published anatomy references and atlases were reviewed and discrepancies were resolved by examination of anatomic specimens and multiplanar reformatted images to describe transverse CT anatomy of LS region paraspinal muscles. Sixteen Belgian malinois military working dogs were retrospectively recruited and assigned to LS pain positive versus negative groups based on medical record entries. A single observer unaware of dog group measured CT transverse areas of paraspinal muscles and adjacent vertebral bodies, in triplicate, for L5-S1 vertebral locations. A statistician compared muscle transverse area ratios and asymmetry at each vertebral location between groups. The relative coefficient of variation for triplicate CT area measurements averaged 2.15% (N = 16). Multifidus lumborum (L6-7), psoas/iliopsoas (L5-6, L6-7), and sacrocaudalis dorsalis lateralis (L6-7, L7-S1) transverse area ratios were significantly smaller in dogs with LS pain (n = 11) versus without LS pain (n = 5) (p ≤ 0.05). Muscle asymmetry values were not significantly greater in dogs with versus without LS pain. Computed tomographic morphometry of LS region paraspinal muscles is a feasible objective method for use in future evidence-based research studies in working dogs. Potential future research applications include determining whether decreased paraspinal muscle area ratios and/or increased paraspinal muscle asymmetry could be used as markers for preclinical LS pain in stoic dogs or risk factors for other injuries in high performance canine athletes, or determining whether core muscle strengthening exercise prescriptions for dogs with LS pain have an effect on paraspinal muscle area ratios and asymmetry.

Anterior Loop of the Inferior Alveolar Canal: A Cone-Beam Computerized Tomography Study of 494 Cases.

The aim of this study was to use cone-beam computerized tomography (CBCT) images of patients to assess the prevalence of different types, especially anterior loop, of the mental portion of the inferior alveolar canal and to evaluate the anterior loop lengths. CBCT images of 494 patients providing inclusion criteria were examined by 2 oral radiologists. Sagittal, axial, and multiplanar reformatted images were used to detect the type of mental portion of the inferior alveolar canal. The anterior loop length was measured in the respective sections of each CBCT image. Statistical analysis was performed using SPSS v. 15, and t tests were used for statistical analysis. Of the 494 patients, 217 anterior loops were detected in 141 (28.5%) patients. The mean anterior loop lengths for the right side and the left side were 2.19 ± 1 mm and 2.08 ± 0.89 mm, respectively. The difference between males and females in the mean anterior loop length was statistically significant for both sides (Right: P < .05; Left: P < .05). A presurgical CBCT image examination is necessary prior to implant insertion to reveal the presence of anterior loop and to detect actual anterior loop length.

Update on current evaluation and management of pediatric nasal dermoid

To review the presentation of congenital pediatric nasal dermoid and present guidelines for its evaluation and management. Retrospective chart review from 1970 to 2014 at a tertiary referral children's hospital. The medical records of all patients diagnosed with a nasal dermoid during the study period were reviewed for demographics, lesion characteristics, imaging, operative details, and outcomes. Ninety-six patients underwent excision of a congenital nasal dermoid during the study period. The mean age at presentation was 3.1 years (range, 0.1-19.3 years). Thirty-four (35%) females and 62 (65%) males were included. The most common presentation was a nasal dorsal mass in 66 (69%) patients. Ninety-two (96%) of the patients underwent preoperative imaging. Seventy-eight (82%) of the patients did not show any clinical or radiographic evidence of intracranial extension preoperatively. Eighty-five (89%) of the patients underwent extracranial excision, and 11 (11%) underwent combined intracranial and extracranial excision. Eight patients (8%) presented with recurrence, on average 3.3 years (range, 1-6 years) after initial excision. Mean follow-up time was 8 years (range, 1-18 years). Preoperative imaging of nasal dermoid is crucial to evaluate for intracranial extension, thus facilitating complete removal. Thin section, high-resolution magnetic resonance with contrast provides excellent detail of the extent of the nasal dermoid including intracranial extension. Thin-section high-resolution computed tomography with multiplanar reformatted images provides complimentary information regarding the bone anatomy of the frontonasal region. Surgical strategy is dictated by preoperative imaging and is dependent on the extent of the lesion, but limited facial incisions are preferred. 4. Laryngoscope, 126:2151-2160, 2016.

Contrast-enhanced Reformatted MR Images for Preoperative Assessment of the Bridging Veins of the Skull Base.

Magnetic resonance (MR) venography and computed tomographic (CT) venography are suited for displaying the convexity veins that drain the medial and lateral surfaces of the brain hemispheres. However, such is not the case for the bridging veins of the skull base. Technical factors prevent contrast material-enhanced MR or CT images obtained in standard axial, coronal, and sagittal planes from fully displaying the curved pathways of these clinically important venous structures. This limitation can be overcome by using a reconstruction technique that depicts these venous structures and their interconnections. Curved and multiplanar reformatted images that distill the important venous features often require knowledgeable manipulation of source images by an operator who is familiar with numerous venous variants and their surgical implications. The normal anatomy of the draining veins is detailed-anatomy that radiologists must master before they can show the surgeon the important venous anatomy that is often missing at standard imaging; this information will foster better communication between radiologists and their surgical colleagues. As a practical matter, the skull base veins are arbitrarily subdivided into those that are at greatest risk with the pterional approach and the subtemporal approach, respectively. These approaches can be expanded to define connections between the superficial venous system and the other valveless venous networks that drain the deep portions of the cerebral hemisphere, the scalp, face, muscles of the neck, diploë of the skull, and meninges. As radiologists gain experience, their image interpretations should mature beyond simple analysis of the primary hemodynamic changes induced by intraoperative sacrifice or injury.

A Current Review of the Meniscus Imaging: Proposition of a Useful Tool for Its Radiologic Analysis.

The main objective of this review was to present a synthesis of the current literature in order to provide a useful tool to clinician in radiologic analysis of the meniscus. All anatomical descriptions were clearly illustrated by MRI, arthroscopy, and/or drawings. The value of standard radiography is extremely limited for the assessment of meniscal injuries but may be indicated to obtain a differential diagnosis such as osteoarthritis. Ultrasound is rarely used as a diagnostic tool for meniscal pathologies and its accuracy is operator-dependent. CT arthrography with multiplanar reconstructions can detect meniscus tears that are not visible on MRI. This technique is also useful in case of MRI contraindications, in postoperative assessment of meniscal sutures and the condition of cartilage covering the articular surfaces. MRI is the most accurate and less invasive method for diagnosing meniscal lesions. MRI allows confirming and characterizing the meniscal lesion, the type, the extension, its association with a cyst, the meniscal extrusion, and assessing cartilage and subchondral bone. New 3D-MRI in three dimensions with isotropic resolution allows the creation of multiplanar reformatted images to obtain from an acquisition in one sectional plane reconstructions in other spatial planes. 3D MRI should further improve the diagnosis of meniscal tears.

ETHMOID ROOF RADIOLOGY; AN ANALYSIS OF 110 PATIENTS

We evaluated the extent of asymmetry evident in paranasal sinus computed tomography (CT) scans of Turkish patients without sinusitis in the ethmoid roof. Our data contribute to the body of knowledge on the subject. We retrospectively studied multiplanar reformatted CT images of the paranasal sinus (1-mm sections) from 110 patients (50 male, 60 female). Ethmoid roof variations on either side were compared and the lateral lamellar length of the cribriform plate was measured. The results were scored using the Keros classification. The lateral lamella of the cribriform plate averaged 5.78 mm in height on the right side and 5.98 mm on the left. The most common Keros type was type 2 (67.72%), followed by type 3 (22.28%), and type 1 (10%). Keros asymmetry (≥ 0.01 mm, affecting either side) was apparent in all patients (48.2% right-sided and 51.8% left-sided). Preoperatively, paranasal sinus CT scans should be evaluated carefully to eliminate the possibility of life-threatening complications, including intracranial trauma, which may develop during endoscopic sinus surgery; the left and right sides of the ethmoid roof may differ in depth.

Optimal imaging protocol for measuring dynamic expiratory collapse of the central airways

To compare measurements of expiratory collapse obtained using multidetector computed tomography (MDCT) of the central airways on routine axial and multiplanar reformatted (MPR) images. Fifty volunteers with normal pulmonary function and no smoking history were imaged using a 64 MDCT system (40mAs, 120kVp, 0.625mm collimation) with spirometric monitoring at end-inspiration and during forced expiration. Measurements of the trachea, right main (RMB) and left main bronchus (LMB) were obtained on axial and MPR images. Inspiratory and dynamic-expiratory cross-sectional area (CSA) measurements were used to calculate the mean percentage expiratory collapse (%Collapse). A paired t-test was used to assess within-subject differences and a Bland-Altman plot was used to assess agreement between the methods. Among 24 men and 26 women (mean age±standard deviation 50±15 years), CSA values were significantly greater on axial than MPR images (all p<0.001); however, the mean difference in %Collapse values for axial versus MPR were small: trachea ≈1% (55 ±19 versus 56±18, p=0.338); LMB identical (60±20 versus 60±17 p=0.856); and, RMB 4% (62 ±19 versus 66±19 p<0.001). On average, creation of MPR required 12 minutes of additional time per case (range=10-15min). Differences in mean %Collapse for axial versus MPR images were small and unlikely to influence clinical management. This finding suggests that MPR may not be indicated for routine assessment of central airway collapse.

Evaluation of the perforators of the anterior communicating artery (AComA) using routine cerebral 3D rotational angiography

BackgroundDamage to perforating branches of the anterior communicating artery (AComA) is a known complication of surgical or interventional treatment procedures for AComA aneurysm leading to neurologic deficits. In spite of...

CT segmentation of dental shapes by anatomy-driven reformation imaging and B-spline modelling.

Dedicated imaging methods are among the most important tools of modern computer-aided medical applications. In the last few years, cone beam computed tomography (CBCT) has gained popularity in digital dentistry for 3D imaging of jawbones and teeth. However, the anatomy of a maxillofacial region complicates the assessment of tooth geometry and anatomical location when using standard orthogonal views of the CT data set. In particular, a tooth is defined by a sub-region, which cannot be easily separated from surrounding tissues by only considering pixel grey-intensity values. For this reason, an image enhancement is usually necessary in order to properly segment tooth geometries. In this paper, an anatomy-driven methodology to reconstruct individual 3D tooth anatomies by processing CBCT data is presented. The main concept is to generate a small set of multi-planar reformation images along significant views for each target tooth, driven by the individual anatomical geometry of a specific patient. The reformation images greatly enhance the clearness of the target tooth contours. A set of meaningful 2D tooth contours is extracted and used to automatically model the overall 3D tooth shape through a B-spline representation. The effectiveness of the methodology has been verified by comparing some anatomy-driven reconstructions of anterior and premolar teeth with those obtained by using standard tooth segmentation tools. Copyright © 2015 John Wiley & Sons, Ltd.

Quantification of Respiratory Movement of the Aorta and Side Branches

Purpose: To assess and quantify the magnitude and direction of respiratory movement of the aorta and origins of its side branches. Methods: A quantitative 3-dimensional (3D) subtraction analysis of computed tomography (CT) scans during inspiration and expiration was performed to determine the respiratory geometric movements of the aorta and side branches in 60 patients. During breath-hold expiration and inspiration, 1-mm-thick CT slices of the aorta were acquired in unenhanced and contrast-enhanced scans. The datasets were compared using dedicated multiplanar reformation image subtraction software to determine the change in position of relevant anatomic sections, including the ascending thoracic aorta (AA), the origins of the brachiocephalic artery (BA) and left subclavian artery (LSA), the descending thoracic aorta (DTA) at the level of the tenth thoracic vertebra, as well as the origins of the celiac trunk, superior mesenteric artery, and the renal arteries. Results: Complex movement was visible during inspiration; the regions of interest in the thoracic aorta and side branches moved in the anterior, medial, and caudal directions compared with the expiration state. Mean 3D movement vectors (± standard deviation) were 8.9±3.6 mm (AA), 12.0±4.1 mm (BA), 11.1±3.9 mm (LSA), and 4.9±2.5 mm (DTA). Abdominal side branches moved in the caudal direction 1.3±1.1 mm. There was significantly less movement in the DTA compared to AA (p<0.001). The correlation coefficient between the extent of LSA movement and thoracic excursion was 0.78. Conclusion: The aorta and side branches undergo considerable respiratory movement. The results from this study provide an important contribution to understanding aortic dynamics.

Diagnostic Value of Multidetector CT and Its Multiplanar Reformation, Volume Rendering and Virtual Bronchoscopy Postprocessing Techniques for Primary Trachea and Main Bronchus Tumors.

PurposeTo evaluate the diagnostic value of multidetector CT (MDCT) and its multiplanar reformation (MPR), volume rendering (VR) and virtual bronchoscopy (VB) postprocessing techniques for primary trachea and main bronchus tumors.MethodsDetection results of 31 primary trachea and main bronchus tumors with MDCT and its MPR, VR and VB postprocessing techniques, were analyzed retrospectively with regard to tumor locations, tumor morphologies, extramural invasions of tumors, longitudinal involvements of tumors, morphologies and extents of luminal stenoses, distances between main bronchus tumors and trachea carinae, and internal features of tumors. The detection results were compared with that of surgery and pathology.ResultsDetection results with MDCT and its MPR, VR and VB were consistent with that of surgery and pathology, included tumor locations (tracheae, n = 19; right main bronchi, n = 6; left main bronchi, n = 6), tumor morphologies (endoluminal nodes with narrow bases, n = 2; endoluminal nodes with wide bases, n = 13; both intraluminal and extraluminal masses, n = 16), extramural invasions of tumors (brokethrough only serous membrane, n = 1; 4.0 mm—56.0 mm, n = 14; no clear border with right atelectasis, n = 1), longitudinal involvements of tumors (3.0 mm, n = 1; 5.0 mm—68.0 mm, n = 29; whole right main bronchus wall and trachea carina, n = 1), morphologies of luminal stenoses (irregular, n = 26; circular, n = 3; eccentric, n = 1; conical, n = 1) and extents (mild, n = 5; moderate, n = 7; severe, n = 19), distances between main bronchus tumors and trachea carinae (16.0 mm, n = 1; invaded trachea carina, n = 1; >20.0 mm, n = 10), and internal features of tumors (fairly homogeneous densities with rather obvious enhancements, n = 26; homogeneous density with obvious enhancement, n = 1; homogeneous density without obvious enhancement, n = 1; not enough homogeneous density with obvious enhancement, n = 1; punctate calcification with obvious enhancement, n = 1; low density without obvious enhancement, n = 1).ConclusionMDCT and its MPR, VR and VB images have respective advantages and disadvantages. Their combination could complement to each other to accurately detect locations, natures (benignancy, malignancy or low malignancy), and quantities (extramural invasions, longitudinal involvements, extents of luminal stenoses, distances between main bronchus tumors and trachea carinae) of primary trachea and main bronchus tumors with crucial information for surgical treatment, are highly useful diagnostic methods for primary trachea and main bronchus tumors.

Multiplanar Reformation of CT Scan for Preoperative Staging of Gastric Cancer

Recent progress on CT such as multi-detector row CT, oral contrast agents and multiplanar reconstruction have markedly improved the image quality as well as diagnostic performance of gastric cancer. Multiplanar reformatted images at predetermined orientations can be easily performed and embedded into routine CT protocol without increasing medical expense or labor. Currently, many institutions have adopted routine multiplanar reformatted protocols and therefore knowledge on them can improve the diagnostic accuracy of gastric cancer.

A Multicenter MRI Protocol for the Evaluation and Quantification of Deep Vein Thrombosis.

We evaluated a magnetic resonance venography (MRV) approach with gadofosveset to quantify total thrombus volume changes as the principal criterion for treatment efficacyin a multicenter randomized study comparing edoxaban monotherapy with a heparin/warfarin regimen for acute, symptomatic lower extremities deep vein thrombosis (DVT) treatment. We also used a direct thrombus imaging approach (DTHI, without the use of a contrast agent) to quantify fresh thrombus. We then sought to evaluate the reproducibility of the analysis methodology and applicability of using 3D magnetic resonance venography and direct thrombus imaging for the quantification of DVT in a multicenter trial setting. From 10 randomly selected subjects participating in the edoxaban Thrombus Reduction Imaging Study (eTRIS), total thrombus volume in the entire lower extremity deep venous system was quantified bilaterally. Subjects were imaged using 3D-T1W gradient echo sequences before (direct thrombus imaging, DTHI) and 5 min after injection of 0.03 mmol/kg of gadofosveset trisodium (magnetic resonance venography, MRV). The margins of the DVT on corresponding axial, curved multi-planar reformatted images were manually delineated by two observers to obtain volumetric measurements of the venous thrombi. MRV was used to compute total DVT volume, whereas DTHI was used to compute volume of fresh thrombus. Intra-class correlation (ICC) and Bland Altman analysis were performed to compare inter and intra-observer variability of the analysis. The ICC for inter and intra-observer variability was excellent (0.99 and 0.98, p <0.001, respectively) with no bias on Bland-Altman analysis for MRV images. For DTHI images, the results were slightly lower (ICC = 0.88 and 0.95 respectively, p <0.001), with bias for inter-observer results on Bland-Altman plots. This study showed feasibility of thrombus volume estimation in DVT using MRV with gadofosveset trisodium, with good intra- and inter-observer reproducibility in a multicenter setting.

Do Foley Catheters Adequately Drain the Bladder? Evidence from CT Imaging Studies.

ABSTRACTIntroduction:The Foley catheter has been widely assumed to be an effective means of draining the bladder. However, recent studies have brought into question its efficacy. The objective of our study is to further assess the adequacy of Foley catheter for complete drainage of the bladder.Materials and Methods:Consecutive catheterized patients were identified from a retrospective review of contrast enhanced and non-contrast enhanced computed tomo-graphic (CT) abdomen and pelvis studies completed from 7/1/2011-6/30/2012. Residual urine volume (RUV) was measured using 5mm axial CT sections as follows: The length (L) and width (W) of the bladder in the section with the greatest cross sectional area was combined with bladder height (H) as determined by multiplanar reformatted images in order to calculate RUV by applying the formula for the volume (V) of a sphere in a cube: V=(ϖ/6)*(L*W*H).Results:RUVs of 167 (mean age 67) consecutively catheterized men (n=72) and women (n=95) identified by CT abdomen and pelvis studies were calculated. The mean RUV was 13.2 mL (range: 0.0 mL-859.1 mL, standard deviation: 75.9 mL, margin of error at 95% confidence:11.6 mL). Four (2.4%) catheterized patients had RUVs of >50 mL, two of whom had an improperly placed catheter tip noted on their CT-reports.Conclusions:Previous studies have shown that up to 43% of catheterized patients had a RUV greater than 50 mL, suggesting inadequacy of bladder drainage via the Foley catheter. Our study indicated that the vast majority of patients with Foley catheters (97.6%), had adequately drained bladders with volumes of <50 mL.

Method of visualisation influences accuracy of measurements in cone-beam computed tomography

This study evaluated the potential impact of different visualisation methods of cone-beam computed tomography (CBCT) on the accuracy of linear measurements of calcified structures, and assessed their interchangeability.High resolution (0.125 mm voxel) CBCT scans were obtained from eight cadaveric heads. The distance between the alveolar bone ridge and the incisal edge was determined for all mandibular incisors and canines, both anatomically and with measurements based on the following five CBCT visualisation methods: isosurface, direct volume rendering, multiplanar reformatting (MPR), maximum intensity projection of the volume of interest (VOIMIP), and average intensity projection of the volume of interest (VOIAvIP). All radiological methods were tested for repeatability and compared with anatomical results for accuracy, and limits of agreement were established. Interchangeability was evaluated by reviewing disparities between the methods and disclosing deterministic differences.Fine intra- and inter-observer repeatability was asserted for all visualisation methods (intraclass correlation coefficient ≤0.81). Measurements were most accurate when performed on MPR images and performed most disappointingly on isosurface-based images. Direct volume rendering, VOIMIP and VOIAvIP achieved acceptable results.It can be concluded that visualisation methods influence the accuracy of CBCT measurements. The isosurface viewing method is not recommended, and multiplanar reformatted images should be favoured for linear measurements of calcified structures.