The Search Patterns of Abdominal Imaging Subspecialists for Abdominal Computed Tomography: Toward a Foundational Pattern for New Radiology Residents

Objectives: The routine search patterns used by subspecialty abdominal imaging experts to inspect the image volumes of abdominal/pelvic computed tomography (CT) have not been well characterized or rendered in practical or teachable terms. The goal of this study is to describe the search patterns used by experienced subspecialty imagers when reading a normal abdominal CT at a modern picture archiving and communication system workstation, and utilize this information to propose guidelines for residents as they learn to interpret CT during training. Material and Methods: Twenty-two academic subspecialists enacted their routine search pattern on a normal contrast-enhanced abdominal/pelvic CT study under standardized display parameters. Readers were told that the scan was normal and then asked to verbalize where their gaze centered and moved through the axial, coronal, and sagittal image stacks, demonstrating eye position with a cursor as needed. A peer coded the reported eye gaze movements and scrilling behavior. Spearman correlation coefficients were calculated between years of professional experience and the numbers of passes through the lung bases, liver, kidneys, and bowel. Results: All readers followed an initial organ-by-organ approach. Larger organs were examined by drilling, while smaller organs by oscillation or scanning. Search elements were classified as drilling, scanning, oscillation, and scrilling (scan drilling); these categories were parsed as necessary. The greatest variability was found in the examination the body wall and bowel/mesentery. Two modes of scrilling were described, and these classified as roaming and zigzagging. The years of experience of the readers did not correlated to number of passes made through the lung bases, liver, kidneys, or bowel. Conclusion: Subspecialty abdominal radiologists negotiate through the image stacks of an abdominal CT study in broadly similar ways. Collation of the approaches suggests a foundational search pattern for new trainees.

Femoral Trochlear Geometry in Patients with Trochlear Dysplasia Using MRI Oblique Trochlear View

The objective of this study was to evaluate trochlear morphology in patients with trochlear dysplasia using a new oblique trochlear magnetic resonance imaging (MRI) view (OTV) in comparison with standard axial MRI sequences. MRI exam of 73 patients with patellofemoral instability (PFI) and the same number of controls were retrospectively reviewed. The oblique trochlear sequence was acquired by inclining the axial plane parallel to the intercondylar roof of the sagittal image, showing the anterior cruciate ligament (ACL) in its entire length. Trochlear morphology was assessed on axial and oblique trochlear sequences at three levels: level 1 at 25%, level 2 at 50%, and level 3 at 75% of the length of the trochlear groove. Trochlear sulcus angle and sulcus depth were measured at these three levels and compared between the new trochlear and standard axial sequences. Trochlear sulcus angle and sulcus depth were statistically different between axial and oblique trochlear views at all three levels (p < 0,05). Additionally, OTV displayed more uniform sulcus angle and depth along the trochlea. The oblique trochlear view on the MRI can more accurately evaluate trochlear morphology and also better characterize trochlear dysplasia in patients with PFI. This is Level III, retrospective comparative study.

Real-Time Automated Segmentation and Classification of Calcaneal Fractures in CT Images

Calcaneus fractures often occur because of accidents during exercise or activities. In general, the detection of the calcaneus fracture is still carried out manually through CT image observation, and as a result, there is a lack of precision in the analysis. This paper proposes a computer-aid method for the calcaneal fracture detection to acquire a faster and more detailed observation. First, the anatomical plane orientation of the tarsal bone in the input image is selected to determine the location of the calcaneus. Then, several fragments of the calcaneus image are detected and marked by color segmentation. The Sanders system is used to classify fractures in transverse and coronal images into four types, based on the number of fragments. In the sagittal image, fractures are classified into three types based on the involvement of the fracture area. The experimental results show that the proposed method achieves a high precision rate of 86%, with a fast computational performance of 133 frames per second (fps), used to analyze the severity of injury to the calcaneus. The results in the test image are validated based on the assessment and evaluation carried out by the physician on the reference datasets.

Lunate fractures and associated radiocarpal and midcarpal instabilities: a systematic review

The aim of this study was to analyse lunate fractures and any associated osseo-ligamentous injuries. A systematic review identified 34 cases. We identified carpal instabilities at the radiocarpal and midcarpal joints in volar and dorsal directions. Radiocarpal instabilities (10/34) were usually dorsoradial (8/10), with a transverse lunate fracture, best seen on a coronal image. Midcarpal instabilities (24/34) were usually volar (14/18), with a volar lunate shear fracture, best seen on a sagittal image. Instabilities were sub-classified into non-displaced, subluxated and dislocated. Associated fractures of the scaphoid and the radial and ulnar styloid processes were common. Lunate fractures without subluxation or dislocation had good outcomes with cast immobilization or fixation of associated fractures. Lunate fracture-subluxations are unstable injuries that are best managed with fixation of the carpal fractures. Lunate fracture-dislocations are complex injuries, requiring stabilization of the lunate, associated fractures and ligament injuries; complications are common and acute or delayed salvage procedures may be required.

The morphology of proximal pole scaphoid fractures: implications for optimal screw placement

The purpose of this study was to measure the radiographic parameters of proximal pole scaphoid fractures, and calculate the ideal starting points and trajectories for antegrade screw insertion. Computed tomography scans of 19 consecutive patients with proximal pole fractures were studied using open source digital imaging and communications in medicine (DICOM) imaging measurement software. For scaphoid sagittal measurements, fracture inclination was measured with respect to the scaphoid axis. The ideal starting point for a screw in the proximal pole fragment was then identified on the scaphoid sagittal image that demonstrated the largest dimensions of the proximal pole, and hence the greatest screw thread purchase. Measurements were then taken for a standard screw trajectory in the axis of the scaphoid, and a trajectory that was perpendicular to the fracture line. The fracture inclination in the scaphoid sagittal plane was 25 (SD10) °, lying from proximal palmar to dorsal distal. The fracture inclination in the coronal plane was 9 (SD16) °, angling distal radial to proximal ulnar with reference to the coronal axis of the scaphoid. Using an ideal starting point that maximized the thread purchase in the proximal pole, we measured a maximum screw length of 20 (SD 2) mm when using a screw trajectory that was perpendicular to the fracture line. This was quite different from the same measurements taken in a trajectory in the axis of the scaphoid. We also identified a mean distance of approximately 10 mm from the dorsal fracture line to the ideal starting point. A precise understanding of this anatomy is critical when treating proximal pole scaphoid fractures surgically.

Accessory Mental Foramen of the Mandible Found With Radiographic Images: A Case Report

The object of this study is to present a case of an accessory mental foramen. Detection of the position of mental foramen is important during surgical procedures in terms of achieving effective mandibular nerve blocks and avoiding injuries to the neurovascular bundles. A 64-year-o1d man visited us for taking treatment. Preoperative panoramic radiography and CT were conducted. A multi-section reconstructed sagittal image showed two mental foramina leading to the mandibular canal on the right side of the mandible, which were considered to be double mental foramina. Although no surgical procedure was planned, the patient was informed about the existence and importance of the anatomical variation with regard to the need for local anesthesia, diagnosis of periapical diseases, and the prevention of nerve damage during surgery in that area of his mandibleJ Shaheed Suhrawardy Med Coll, 2014; 6(2):90-92

Posterior Epidural Migration of a Sequestrated Lumbar Disk Fragment Causing Cauda Equina Syndrome in an Old Patient: A Case Report

Disk fragment relocation is commonly limited to the anterior epidural space, although posterior epidural movement of a sequestrated disk piece to the posterior epidural space is in frequent. We present an uncommon case of dorsal extradural sequestration of lumbar disk herniation. A 77-year-old man presented with severe leg pain, low back pain, and urinary incontinence. Deep tendon reflexes were inattentive at the knee and ankle, and the motor power in terms of ankle dorsiflexion and great toe dorsiflexion was 2/5 in both lower limbs. There was hypoesthesia in the S1, S2, and S3 dermatomes. Magnetic resonance imaging displayed a large isointensity lesion at the L4–L5 level on the T2 sagittal image, indenting circumferentially the thecal sac from lateral to posterior of the thecal sac. The patient underwent an L4–L5 central laminectomy. A large, solid epidural disk fragment was recognized dorsally, with major compression of the thecal sac. The patient report improved lower extremity motor function at three-month follow-up. A displaced disk fragment should be considered as causative when patients present with cauda equine syndrome and be treated as a surgical emergency.

Abstract P182: Aortic Arch Pulse Wave Velocity Assessed by MRI as a Predictor of All-Cause Mortality and Incident Cardiovascular Events: The Multi-Ethnic Study of Atherosclerosis (MESA)

Background: The carotid-femoral pulse wave velocity (PWV) assessed by tonometry is predictive of future cardiovascular disease (CVD) events. However, the predictive value of aortic arch PWV assessed by MRI for mortality and CVD events has not been established in the general population. The aim of this study was to evaluate the association of arch PWV with all-cause mortality and incident CVD events over 10 years in the Multi-Ethnic Study of Atherosclerosis (MESA). Method: Aortic arch PWV was measured using phase contrast (PC) cine MRI at the level of the pulmonary artery bifurcation for transit time and black blood sagittal image for transit length at baseline in 3537 MESA participants free of overt CVD. Cox regression was used to evaluate the risk of death and incident CVD in relation to arch PWV adjusted for age, gender, race, and CV risk factors. Results: At baseline, participants were aged 62 ± 10 years; 53% women; 36% White, 15% Chinese, 29% African American, 20% Hispanic; 45% hypertension. The mean value of arch PWV was 9.0 ± 6.3 m/s. There were 418 deaths and 236 CVD events over 10-year follow-up. There was significant interaction between arch PWV and mean age for both outcomes, so we stratified by age; below 60 years (n=1503) and above 60 years (n=2034). Increased PWV had a trend with increased risk of all-cause mortality with a hazard ratio for the 4th vs 1st quartile of PWV of 2.1 (95%CI: 1.0-4.6, p=0.05) independent of risk factors in age below 60 years group. There was no significant association of PWV with incident CVD in age below 60 years after adjustment for risk factors. In age above 60 years group, increased PWV was not associated with either all-cause mortality or incident CVD events in univariate or multivariate analysis (Table). Conclusion: Arch PWV assessed by MRI is not a significant predictor of all-cause mortality and incident CVD events among individuals without overt CVD.