Visualization Of Anatomic Landmarks Research Articles

Technological advancements in surgical laparoscopy considering artificial intelligence: a survey among surgeons in Germany

PurposeThe integration of artificial intelligence (AI) into surgical laparoscopy has shown promising results in recent years. This survey aims to investigate the inconveniences of current conventional laparoscopy and to evaluate the attitudes and desires of surgeons in Germany towards new AI-based laparoscopic systems.MethodsA 12-item web-based questionnaire was distributed to 38 German university hospitals as well as to a Germany-wide voluntary hospital association (CLINOTEL) consisting of 66 hospitals between July and November 2022.ResultsA total of 202 questionnaires were completed. The majority of respondents (88.1%) stated that they needed one assistant during laparoscopy and rated the assistants’ skillfulness as “very important” (39.6%) or “important” (49.5%). The most uncomfortable aspects of conventional laparoscopy were inappropriate camera movement (73.8%) and lens condensation (73.3%). Selected features that should be included in a new laparoscopic system were simple and intuitive maneuverability (81.2%), automatic de-fogging (80.7%), and self-cleaning of camera (77.2%). Furthermore, AI-based features were improvement of camera positioning (71.3%), visualization of anatomical landmarks (67.3%), image stabilization (66.8%), and tissue damage protection (59.4%). The reason for purchasing an AI-based system was to improve patient safety (86.1%); the reasonable price was €50.000–100.000 (34.2%), and it was expected to replace the existing assistants’ workflow up to 25% (41.6%).ConclusionSimple and intuitive maneuverability with improved and image-stabilized camera guidance in combination with a lens cleaning system as well as AI-based augmentation of anatomical landmarks and tissue damage protection seem to be significant requirements for the further development of laparoscopic systems.

Three-Dimensional Preoperative Planning Software for Hip Resurfacing Arthroplasty.

Three-dimensional planning of hip arthroplasty is associated with better visualisation of anatomical landmarks and enhanced mapping for preoperative implant sizing, which can lead to a decrease in surgical time and complications. Despite the advantages of hip resurfacing arthroplasty (HRA), it is considered a technically challenging procedure and associated with inaccurate implant placement. This study aimed to examine the validity, reliability, and usability of preoperative 3D Hip Planner software for HRA. Fifty random cases of various hip osteoarthritis severity were planned twice by two junior trainees using the 3D Hip Planner within a one-month interval. Outcome measures included femoral/cup implant size, stem-shaft angle, and cup inclination angle, and were assessed by comparing outcomes from 2D and 3D planning. An adapted unified theory of acceptance and use of technology (UTAUT) survey was used for software usability. Bland-Altman plots between 3D and 2D planning for stem-shaft and inclination angles showed mean differences of 0.7 and -0.6, respectively (r = 0.93, p < 0.001). Stem-shaft and inclination angles showed inter-rater reliability biases of around -2° and 3°, respectively. Chi-square and Pearson's correlation for femoral implant size showed a significant association between the two assessors (r = 0.91, p < 0.001). The 3D test-retest coefficient of repeatability for stem-shaft and inclination angles were around ±2° and ±3°, respectively, with a strong significant association for femoral implant size (r = 0.98, p < 0.001). Survey analyses showed that 70-90% agreed that 3D planning improved expectancy in four domains. 3D hip planner appears to be valid and reliable in preoperative HRA and shows significant potential in optimising the quality and accuracy of surgical planning.

Novel deep learning-based noise reduction technique for prostate magnetic resonance imaging

IntroductionMagnetic resonance imaging (MRI) has played an increasingly major role in the evaluation of patients with prostate cancer, although prostate MRI presents several technical challenges. Newer techniques, such as deep learning (DL), have been applied to medical imaging, leading to improvements in image quality. Our goal is to evaluate the performance of a new deep learning-based reconstruction method, “DLR” in improving image quality and mitigating artifacts, which is now commercially available as AIRTM Recon DL (GE Healthcare, Waukesha, WI). We hypothesize that applying DLR to the T2WI images of the prostate provides improved image quality and reduced artifacts.MethodsThis study included 31 patients with a history of prostate cancer that had a multiparametric MRI of the prostate with an endorectal coil (ERC) at 1.5 T or 3.0 T. Four series of T2-weighted images were generated in total: one set with the ERC signal turned on (ERC) and another set with the ERC signal turned off (Non-ERC). Each of these sets then reconstructed using two different reconstruction methods: conventional reconstruction (Conv) and DL Recon (DLR): ERCDLR, ERCConv, Non-ERCDLR, and Non-ERCConv. Three radiologists independently reviewed and scored the four sets of images for (i) image quality, (ii) artifacts, and (iii) visualization of anatomical landmarks and tumor.ResultsThe Non-ERCDLR scored as the best series for (i) overall image quality (p < 0.001), (ii) reduced artifacts (p < 0.001), and (iii) visualization of anatomical landmarks and tumor.ConclusionProstate imaging without the use of an endorectal coil could benefit from deep learning reconstruction as demonstrated with T2-weighted imaging MRI evaluations of the prostate.

Human gastric magnet-controlled capsule endoscopy conducted in a standing position: the phase 1 study

BackgroundCurrent magnet-controlled capsule endoscopy (MCE) for the stomach is not yet satisfactory with respect to navigation control, especially in the gastric fundus and cardia. A newly developed MCE system conducted in a standing rather than supine position may improve capsule maneuverability within the stomach. The aim of this phase 1 study was to assess the feasibility and safety of this system for examining the human stomach in healthy volunteers.MethodsA cohort of 31 healthy volunteers were enrolled. Each swallowed a capsule after drinking water and gas producing agents intended to produce distention. Under the newly developed standing MCE system, subjects were examined endoscopically while standing with external guide magnets placed on the abdominal wall and left lower chest. Safety, gastric preparation, maneuverability, visualization of anatomical landmarks and the gastric mucosa, and examination time were the primary parameters assessed. The gastric preparation and examination procedures were well accepted by the subjects and there were no adverse events.ResultsGastric examination took 27.8 ± 8.3 min (12–45 min). Gastric cleanliness was good in 24 participants (77.4%) and moderate in 7 participants (22.6%). Gastric distention was good in all of 31 participants (100%). Capsule maneuverability was also graded as good in all 31 subjects (100%), and manipulation in the fundus and cardia regions was as easy as that in the antrum and body. Visualization of the gastric cardia, fundus, body, angulus, antrum and pylorus was assessed subjectively as complete in all 31 subjects (100%). Visualization of the gastric mucosa was also good (> 75%) in all 31 subjects (100%). In areas where the mucosa could not be visualized, the low visibility was due to opaque fluid or foam. Polyps and erosive lesions were found in 25 subjects.ConclusionMCE of the stomach conducted in a standing position is feasible and safe with satisfactory maneuverability.

Post total knee arthroplasty alignment of 347 consecutive obese patients receiving a fixed distal femoral cut of 6° valgus

This study examined post-total knee arthroplasty (TKA) mechanical axis (MA), measured on hip-to-ankle radiographs, for patients with a body mass index (BMI) > 30 when a fixed 6° valgus distal femoral cut was made. A retrospective radiographic review included 347 TKAs receiving a distal femoral cut of 6° valgus. A distal femoral cut of 6° valgus successful established a neutral, ±3° MA in 86.7% of the 347 obese patients, with a slight tendency toward varus in patients with a BMI>40. A fixed cut may provide more consistent post-TKA alignment, when visualization of anatomical landmarks is made difficult by increased adipose tissue.

Leg length discrepancy after total hip arthroplasty: Can leg length be satisfactorily controlled via anterior approach without a traction table? Evaluation in 56 patients with EOS 3D

BackgroundLeg length discrepancy (LLD) occurs in about 25% of cases after total hip arthroplasty (THA) and adversely affects function if greater than 10mm. When using the direct anterior approach (DAA), limb length control is considered easier with a standard operating table than with a traction table. However, this assumption has not been confirmed. More specifically, no studies have used EOS imaging, which is currently the reference for assessing limb length. The objectives of this retrospective study were: (1) to use EOS imaging to determine whether THA via the DAA on a standard table allowed satisfactory limb length control; (2) whether LLD was associated with other parameters such as age, gender, body mass index (BMI), or side; and (3) to compare clinical score values between patients with and without LLD. HypothesisThe DAA without a traction table allows satisfactory limb length control as assessed using 3D EOS imaging. Material and methodsThis retrospective descriptive study included 56 patients who underwent primary THA via the DAA between March 2013 and June 2014. LLD was measured on pre- and post-operative EOS images, using sterEOS™ 3D software. Age, gender, BMI, and side of THA were collected. The 12-item Short Form score, Harris Hip Score, and Postel-Merle d’Aubigné score were determined to look for radio-clinical correlations. ResultsOf the 56 patients, 15 (26.8%) had an LLD >10mm before THA and 12 (21.4%) after THA. Limb length equality was restored in 7 patients with 1 with a shorter and 1 with a longer limb before THA. In 5 patients with equal limb length before THA, the operated limb was lengthened after THA, by a mean of 8.92mm (range, 5.8–10.8mm). Thus, in all, 5/56 (8.9%) patients experienced a detrimental change in limb length due to the surgery. No statistically significant differences were found between patients with and without LLD regarding age, gender, BMI, side, or clinical scores. DiscussionAlthough the frequency of LLD after THA in our study was consistent with earlier reports, our results show that good limb length control can be obtained via the DAA with a standard operating table. Thus, 7 of the 11 patients with a shorter limb and 1 of 4 with a longer limb before THA had equal limb lengths after THA, and only 8.9% of patients experienced a detrimental increase in limb length after THA. The DAA without a traction table allows satisfactory intra-operative limb length control based on visualisation of anatomical landmarks (antero-superior iliac spines and medial malleoli). This technique is therefore valuable for limiting the risk of LLD. When combined with 3D EOS planning, it may increase the accuracy of limb length adjustment. Level of evidenceIV, retrospective study with no control group.

Hybrid procedure for total laryngectomy with a flexible robot-assisted surgical system.

Total laryngectomy is a standard procedure in head-and-neck surgery for the treatment of cancer patients. Recent clinical experiences have indicated a clinical benefit for patients undergoing transoral robot-assisted total laryngectomy (TORS-TL) with commercially available systems. Here, a new hybrid procedure for total laryngectomy is presented. TORS-TL was performed in human cadavers (n = 3) using a transoral-transcervical hybrid procedure. The transoral approach was performed with a robotic flexible robot-assisted surgical system (Flex®) and compatible flexible instruments. Transoral access and visualization of anatomical landmarks were studied in detail. Total laryngectomy is feasible with a combined transoral-transcervical approach using the flexible robot-assisted surgical system. Transoral visualization of all anatomical structures is sufficient. The flexible design of the robot is advantageous for transoral surgery of the laryngeal structures. Transoral robot assisted surgery has the potential to reduce morbidity, hospital time and fistula rates in a selected group of patients. Initial clinical studies and further development of supplemental tools are in progress. Copyright © 2016 John Wiley & Sons, Ltd.

Thoracoscopic repair of esophageal atresia with and without tracheoesophageal fistula

Esophageal atresia (EA) is the interruption of the continuity of the esophagus, with or without persistent communication with the trachea. Recent advances in surgical techniques have made possible correction with minimally invasive surgery (MIS). To evaluate the management of thoracoscopic technique in the treatment of EA. Retrospective analysis of medical records in two centers was carried out between 2007 and 2012. Variables such as gestational age, gender, weight, type of esophageal atresia, malformations, surgery and postoperative complications were recorded. Twenty patients, 15 of them with type III EA, 4 with type I and one unclassifiable, were part of the study. 13 patients underwent ligation, cut of tracheoesophageal fistula and end to end anastomosis. Two underwent laparoscopic gastrostomy and fistula ligation. One patient required conversion and underwent esophagostomy plus gastrostomy. 4 patients without fistula required laparoscopic gastrostomy and aspiration of the proximal esophagus to be able to perform esophageal anastomosis. In the postoperative period, pleural drainage and a transanastomotic feeding tube were installed. Seven patients required esophageal dilations and 4 patients developed stenosis due to reflux. Two had recurrent fistula, one with spontaneous resolution and another with endoscopic resolution. Three children died: two of them due to pathologies not related to surgery and one as a result of limitation of therapeutic effort after fistula patency. Esophageal atresia repair with MIS is a safe and effective option with excellent exposure and visualization of anatomic landmarks and little associated morbidity.

VALIDATION OF A NOVEL TECHNIQUE FOR CREATING SIMULATED RADIOGRAPHS USING COMPUTED TOMOGRAPHY DATASETS

Understanding radiographic anatomy and the effects of varying patient and radiographic tube positioning on image quality can be a challenge for students. The purposes of this study were to develop and validate a novel technique for creating simulated radiographs using computed tomography (CT) datasets. A DICOM viewer (ORS Visual) plug-in was developed with the ability to move and deform cuboidal volumetric CT datasets, and to produce images simulating the effects of tube-patient-detector distance and angulation. Computed tomographic datasets were acquired from two dogs, one cat, and one horse. Simulated radiographs of different body parts (n = 9) were produced using different angles to mimic conventional projections, before actual digital radiographs were obtained using the same projections. These studies (n = 18) were then submitted to 10 board-certified radiologists who were asked to score visualization of anatomical landmarks, depiction of patient positioning, realism of distortion/magnification, and image quality. No significant differences between simulated and actual radiographs were found for anatomic structure visualization and patient positioning in the majority of body parts. For the assessment of radiographic realism, no significant differences were found between simulated and digital radiographs for canine pelvis, equine tarsus, and feline abdomen body parts. Overall, image quality and contrast resolution of simulated radiographs were considered satisfactory. Findings from the current study indicated that radiographs simulated using this new technique are comparable to actual digital radiographs. Further studies are needed to apply this technique in developing interactive tools for teaching radiographic anatomy and the effects of varying patient and tube positioning.

Ultrasound in labor: a caregiver's perspective

In the last decade, the use of ultrasound in labor has been the subject of much research. Suggested applications include confirmation of fetal viability, identification of fetal presentation and assessment of fetal occiput position and head descent. Nevertheless, it is not clear whether this has changed the practice of caregivers outside the research context; and if it has, it is not clear how. In order to assess this, we performed a survey in April 2012 among participants on courses on prenatal medicine and obstetric ultrasound at the Department of Obstetrics and Gynecology of the Sant'Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy. Participants whose duties included management of labor were invited to answer an online questionnaire. In total, 264 attending physicians completed the questionnaire. The most relevant results are displayed in Table 1. According to our survey, the most popular application of ultrasound in labor was for assessment of fetal occiput position (Table 1). This finding is not surprising given that transabdominal sonographic identification of fetal occiput position is easy to achieve through visualization of anatomical landmarks, such as fetal orbits and the spine, as well as requiring minimal time123. Furthermore, a number of studies have demonstrated the superiority of ultrasound over digital examination for this aim, and are consistent and unequivocal in their support of its use as the gold standard for this clinically important variable123. Sonographic assessment of fetal head position can offer extremely valuable information in certain clinical situations, for instance before instrumental delivery, whereas it seems to be a poor predictor of mode of delivery3, 4. On the other hand, ultrasound was less widely used among survey participants for the assessment of fetal head station and progression (Table 1). We suggest three main obstacles to the application of sonography for this purpose. The first is accessibility to ultrasound equipment; less than half of the participants had an ultrasound machine permanently stationed in their delivery suite. The second obstacle is the absence of convincing data on the utility of ultrasound for this purpose. Lastly, the complexity of the sonographic parameters suggested so far may partially impede the implementation of ultrasound for evaluation of the progression of labor in clinical practice. We acknowledge that more detailed questions about each intrapartum ultrasound parameter would have been useful, however the main goal of this survey was not a comparison between individual parameters. We do also recognize a potential bias in our data. As the chief subject of our courses is ultrasound in obstetrics, the participants who answered the questionnaire are likely to be more experienced in ultrasound than other personnel working in the labor ward. Our survey provides original data on the current use of ultrasonography in the labor ward from the key perspective of the caregiver. It suggests that the publication of more convincing, clinically applicable data and the development of less complex sonographic methods, as encouraged in a recent Opinion article in this Journal3, would promote wider use of intrapartum sonography, especially for the assessment of fetal head descent. A. Youssef*†, T. Ghi†, E. E. Awad‡, E. Maroni†, E. Montaguti†, N. Rizzo† and G. Pilu† †Department of Obstetrics and Gynecology, Sant'Orsola Malpighi Hospital, University of Bologna, Via Massarenti 13, 40138 Bologna, Italy; ‡Department of Obstetrics and Gynecology, El-Shatby Hospital, University of Alexandria, Egypt *Correspondence. (e-mail: [email protected])

Post TLH Ureteral Reimplantation and Burch

This video is meant to demonstrate the use of MIS to address a known serious complication of laparoscopic surgery, uretero-vaginal fistula after total laparoscopic hysterectomy. In this case a uretero-vaginal fistula and SUI are treated by Robotic ureteral dissection, bladder mobilization, ureteral reimplantation and then a Robotic Burch bladder neck retropubic urethropexy. Because of the need to fully mobilize the bladder, visualization of anatomic land marks is excellent and demonstrated in this video abstract.

VHM08 Water Immersion Colonoscopy Technique

VHM08 Water Immersion Colonoscopy Technique

Three-Dimensional Modeling of the Temporal Bone for Surgical Training

The anatomy of the temporal bone (TB) can only be mastered by repeated surgical and anatomic dissections, and surgical teaching initiative had a major effect on outcomes. The aim of this study was to investigate the validity of an artificial TB model devoted to surgical training and education. A helical computed tomographic (CT) scan was used to acquire high-resolution data of cadaveric TB. Digital imaging and communications in medicine (DICOM) data were converted into.stl files after data processing. Cadaveric TBs were prototyped using stereolithography. The validation of the prototype needed several steps. First of all, we have studied on CT scan the positional relationship between the facial nerve and other structures of the cadaveric TBs and prototyped bones. Otoendoscopy of the middle ear and the internal acoustic canal and visualization of anatomic landmarks during TB drilling of the cadaveric TBs and prototyped bones were also performed. Seven normal CT scans of cadaveric TB were selected to make prototyped bone using stereolithography. Measurements of volume and distance showed no significant difference between prototypes and cadaver TBs. Classic mastoid surgical procedures were performed in the Anatomy Department: exposing sigmoid sinus, facial nerve, labyrinth, dura mater, jugular bulb, and internal carotid artery. Two simulations of implantable middle ear prosthesis were made successfully. These prototypes made using stereolithography seem to be a good anatomic model for surgical training. This model could also be interesting for surgical planning in congenital ear anomalies before middle ear prosthesis implantation.

Ultrasound guided thoracic paravertebral block in breast surgery

Thoracic paravertebral block has usually been performed using a loss of resistance technique [1, 2] with the transverse process is an important landmark. However, since the transverse process is neither visible nor palpable, its location is unknown until the block needle encounters the bone. If it is not encountered, the needle tip might advance further causing pleural puncture. Pusch et al. showed that ultrasound scanning of the transverse process and parietal pleura gave an accurate reading of the depth to the paravertebral space [3], but only made the measurements before, not during paravertebral block at T4. Breast surgery is often performed with axillary dissection making additional thoracic paravertebral blocks necessary at several vertebrae. We sought to determine whether visualisation of anatomical landmarks, needle advancement and the spread of local anaesthetic in the paravertebral space as well as knowledge of the distance from the skin to those landmarks using ultrasound imaging could help perform the block at both T1 and T4. With Institutional Review Board approval and written informed consent, 25 healthy patients undergoing unilateral breast surgery received thoracic paravertebral block combined with general anaesthesia. They were placed in the lateral decubitus position with the side to be blocked uppermost. A 3–11 MHz linear array probe (Philips SONOS 5500; Philips Medical Systems, Andover, MA, USA) was applied longitudinally to the paravertebral area. An 18G Tuohy needle was inserted perpendicularly at T4 to hit the transverse process via an out-of-plane approach. This was then directed over the top of the bony structure. The deviation of the needle from the perpendicular line was kept at 15°. The paravertebral space was identified using loss of resistance to normal saline injection without ultrasound. After negative aspiration, 15 ml of 0.5% ropivacaine was administered incrementally under ultrasound guidance. Thoracic paravertebral block at T1 was performed using the same technique with 5 ml of solution. Sensory block was assessed by loss of cold sensation 10 min later. All patients received the block at T4 and 22 at T1. Both parietal pleura and transverse process were successfully visualised at T4 (Fig. 3a) in all patients, while only transverse process visualisation was possible at T1. The distances measured using ultrasound and needle depth are in Table 1. Distances measured using ultrasound correlated well with needle depth. Injection of local anaesthetic was visualised as turbulence at T4 in all patients. Downward movement of pleura was observed at T4 in four patients during injection (Fig. 3b). No accidental pleural puncture occurred. All patients had loss of cold sensation at least between T2 and T4. Ultrasound imaging not only helped determine needle insertion sites, but also provides information on the depth to the paravertebral space. Ultrasound imaging may make thoracic paravertebral block easier to perform and help avoid inadvertent pleural puncture. (a) Measurements of the distances from the skin to the transverse process and pleura on ultrasound longitudinal image at T4. TP = transverse process, PP = parietal pleura, LIG = intertransverse and superior costotransverse ligaments. , distance from the skin to TP; , distance from the skin to PP. (b) Visualisation of local anaesthetic and the downward shift of PP on ultrasound longitudinal image. (A) Before injection, (B) After injection. TP = transverse process, PP = parietal pleura, LA = local anaesthetic.

Magnetic resonance cisternography for preoperative evaluation of arachnoid cysts

With a high likelihood of clinical improvement and low rates of complications, minimally invasive neuroendoscopic surgery is becoming the treatment of choice for symptomatic or growing arachnoid cysts. In neuroendoscopic surgery, visualization of anatomical landmarks is essential in achieving successful fenestration without complications. Because of the restricted visual field in neuroendoscopic surgery, preoperative anatomical assessment is very helpful. Magnetic resonance cisternography (MRC) with high spatial resolution and contrast, using for example 3-D Fourier transformation constructive interference in steady state (CISS) or fast imaging employing steady-state acquisition (FIESTA) sequences, is able to detect the arachnoid cyst wall and neighboring anatomical structures as the anatomical landmarks. We retrospectively reviewed T2-weighted (T2-W) fast spin-echo images, and the MRC and intraoperative findings. Axial and coronal T2-W images (6 and 3 mm thickness, respectively) and axial and coronal 0.8 mm thick MRC images with CISS or FIESTA were obtained from four patients with arachnoid cysts treated by neuroendoscopic surgery. Intraoperative findings were reviewed on videotape recorded during the procedures. At the brain surface, the arachnoid cyst wall could be detected clearly in any of the four patients on MRC images, and was only partly seen in the fourth patient T2-W images. Adjacent important anatomical structures including vessels and cranial nerves, and an enough space for cystocisternostomy were identified on MRC images, and the findings were consistent with the findings during neuroendoscopic surgery. Preoperative identification of the arachnoid cyst wall and surrounding anatomical structures by MRC may help avoid complications and allow safer neuroendoscopic surgery.

Positioning of the wrist for scaphoid radiography

Purpose The purpose of this cadaver study was to determine the ideal position of the wrist for scaphoid radiography. Materials and methods Four cadaver wrists were rotated around their longitudinal axis in 15° increments and exposures were taken. Seven postero-anterior images were taken as well. Thus, 18 images of each wrist were available for assessment. Views were determined in which the main anatomic regions of the scaphoid were visualized undistorted. The size and localization of the overlap of other carpal bones were also evaluated. Finally, views with the best visualization of anatomic landmarks were selected. The results of these three investigations were compared to literature data. Results We consider the following four images the most valuable in the diagnostic imaging of scaphoid bone: (1) Postero-anterior view in ulnar deviation of wrist and fist position of the hand; (2) oblique view in 60° of pronation; (3) oblique view in 60° of supination; (4) lateral view. Conclusion We concluded that our four views are sufficient for proper radiographic evaluation of the scaphoid.

Coronal Ultra-Thick Multiplanar CT Reconstructions (MPR) of the Pelvis in the Multiple Trauma Patient: An Alternative for the Initial Conventional Radiograph

Multiple trauma patients with clinically suspected pelvic fractures often directly undergo a CT scan. However, the initial portable pelvis film (PPF) for further follow-up is then not available. This study examines whether coronal ultra-thick multiplanar reconstructions from CT data are similar when compared with the initial PPF, thus having the potential to serve as an alternative baseline image. Initial PPF and coronal ultra-thick multiplanar CT reconstructions of 33 multiple trauma patients with pelvic fractures were retrospectively analyzed by two independent radiologists with regard to image quality, visualization of anatomical landmarks, and diagnostic accuracy. The primary diagnosis of pelvic fractures was made by using thin axial CT images and thin slice coronal and sagittal reconstructions and served as the standard of reference. Coronal ultra-thick multiplanar CT reconstructions were superior to PPF regarding image adjustment (p < 0.02), absence of overlaying structures (p < 0.05), and overall image quality (p < 0.01). Visualization of most anatomical landmarks was similar with both modalities, except of the iliosacral joint and acetabular lines which were more accurately depicted on ultra-thick multiplanar CT reconstructions (p < 0.05). Diagnostic accuracy of coronal ultra-thick CT reconstructions was similar to PPF regarding most fracture types, except of a higher accuracy of coronal ultra-thick CT reconstructions for iliosacral joint and acetabular column fractures (p < 0.05). Coronal ultra-thick multiplanar CT reconstructions of the pelvis provide similar image quality and diagnostic accuracy compared to PPF and are therefore suited as alternative baseline image in multiple trauma patients who directly undergo CT.

A Blinded Assessment of Radiographic Criteria for Atlanto-occipital Dislocation

Blinded comparison of 5 methods to diagnose atlanto-occipital dislocation (AOD) on plain radiographs and computerized tomography (CT) of the cervical spine. To determine the best method to diagnose AOD. Several methods are proposed for the diagnosis of AOD, including the Power's ratio, X-line method, basion-dens interval, condylar gap, and Harris method. No blinded comparison of the results of these methods has been compared to patient outcome, and there is no information available regarding the accuracy of these methods applied to CT scans. Plain lateral radiographs and CTs of the cervical spine were reviewed in 104 patients, including 6 with AOD. Images underwent a blinded review by a board certified neurosurgeon (D.K.R.), orthopedist (P.A.A.), radiologist (J.C.), and emergency physician (D.B.B.). Each diagnostic method for AOD was applied for determination of sensitivity, specificity, and positive and negative predictive values. The ability to identify relevant anatomic landmarks was also tabulated. Average values for sensitivities, specificities, positive and negative predictive values for each method applied to plain radiographs are: 0.4625-1.0, 0.8933-0.9725, 0.2775-0.45, and 0.975-1.0, respectively. These values for each method applied to CT scans are: 0.7075-1.0, 0.8725-0.9775, 0.3175-1, and 0.98-1.0, respectively. Identification of relevant anatomic landmarks occurred 99.75% of the time when these methods were applied to CT scans compared to 39% to 84% of the time on plain radiographs. Sensitivity, specificity, positive and negative predictive values of these methods improve when applied to CT scans because of better visualization of anatomic landmarks. This result suggests CT scans of the cervical spine may be warranted in all trauma patients suspected of having cervical spine injury.

The importance of accurate anatomic assessment for the volumetric analysis of the amygdala

There is a wide range of values reported in volumetric studies of the amygdala. The use of single plane thick magnetic resonance imaging (MRI) may prevent the correct visualization of anatomic landmarks and yield imprecise results. To assess whether there is a difference between volumetric analysis of the amygdala performed with single plane MRI 3-mm slices and with multiplanar analysis of MRI 1-mm slices, we studied healthy subjects and patients with temporal lobe epilepsy. We performed manual delineation of the amygdala on T1-weighted inversion recovery, 3-mm coronal slices and manual delineation of the amygdala on three-dimensional volumetric T1-weighted images with 1-mm slice thickness. The data were compared using a dependent t-test. There was a significant difference between the volumes obtained by the coronal plane-based measurements and the volumes obtained by three-dimensional analysis (P < 0.001). An incorrect estimate of the amygdala volume may preclude a correct analysis of the biological effects of alterations in amygdala volume. Three-dimensional analysis is preferred because it is based on more extensive anatomical assessment and the results are similar to those obtained in post-mortem studies.

Intelligent training system integrated in an echocardiography simulator

Computer simulators play an important role in medical education. We have extended our simulator EchoComJ with an intelligent training system (ITS) to support trainees adjusting echocardiographic standard views. EchoComJ is an augmented reality application that combines real three-dimensional ultrasound data with a virtual heart model enabling one to simulate an echocardiographic examination. The ITS analyzes the image planes according to their position, orientation and the visualization of anatomical landmarks using fuzzy rules. An adaptive feedback is provided that colors the specific anatomic landmarks within the contours of the virtual model based on the quality of the image plane.