Volume-rendered Reconstructions Research Articles

Demonstrating the empirical effect of population specificity of anthropological standards in a contemporary Australian population

The ability to differentiate individuals based on their biological sex is essential for the creation of an accurate anthropological assessment; it is therefore crucial that the standards that facilitate this are likewise accurate. Given the relative paucity of population-specific anthropological standards formulated specifically for application in the contemporary Australian population, forensic anthropological assessments have historically relied on the application of established methods developed using population geographically and/or temporally disparate. The aim of the present paper is, therefore, to assess the accuracy and reliability of established cranial sex estimation methods, developed from geographically distinct populations, as applied to the contemporary Australian population. Comparison between the original stated accuracy and sex bias values (where applicable) and those achieved after application to the Australian population provides insight into the importance of having anthropological standards optimised for application in specific jurisdictions. The sample analysed comprised computed tomographic (CT) cranial scans of 771 (385 female and 386 male) individuals collected from five Australian states/territories. Cranial CT scans were visualised as three-dimensional volume-rendered reconstructions using OsiriX®. On each cranium, 76 cranial landmarks were acquired, and 36 linear inter-landmark measurements were calculated using MorphDB. A total of 35 predictive models taken from Giles and Elliot (1963), Iscan et al. (1995), Ogawa et al. (2013), Steyn and İşcan (1998) and Kranioti et al. (2008) were tested. Application to the Australian population resulted in an average decrease in accuracy of 21.2%, with an associated sex bias range between − 64.0 and 99.7% (average sex bias value of 29.6%), relative to the original studies. The present investigation has highlighted the inherent inaccuracies of applying models derived from geographically and/or temporally disparate populations. It is, therefore, imperative that statistical models developed from a population consistent with the decedent be used for the estimation of sex in forensic casework.

Preoperative Triple-Phase Three-Dimensional-Multi-Detector Computed Tomography Imaging of the Hepatic Vascular Tree: An Accurate Road Map Prior to Tumor Resection in Hepatoblastoma.

To evaluate the hepatic vasculature/tumor relations in hepatoblastoma patients with three-dimensional (3D) reformatted images after triple-phase multi-detector computed tomography (MDCT) and to compare these with the surgical findings to judge the accuracy of this investigation. The study was carried out in hepatoblastoma patients after appropriate neo-adjuvant chemotherapy, prior to resection. Images were postprocessed at a dedicated workstation for multi-planar reformations, maximum intensity projection, curved planar reformations, and volume-rendered technique reconstructions. The reporting was done as per a specific protocol by both the radiologist and surgeon (per-operative findings) and the accuracy of MDCT ascertained as per concordance between the surgical and imaging findings. Fourteen children (13 boys, 1 girl) underwent surgery. Clinically, relevant information regarding vascular, tumor involvement, and interface with vessels was provided by the study in all cases. Although all tumors were deemed resectable on preoperative imaging, one procedure was abandoned due to an unanticipated portal cavernoma. While a few anatomical variations were unexpectedly encountered during surgery, there was good concordance overall between findings on imaging and surgical exploration. MDCT with 3D reformatting provides accurate virtual representations of the hepatic tumor. This allows simulation of surgical resection with decreased risk of vascular injury and postoperative liver failure.

Visualization of acute aortic injury with cinematic rendering.

The purpose of this study is to demonstrate the appearance of traumatic aortic injuries with the novel 3-dimensional (3D) computed tomography (CT) visualization technique known as cinematic rendering (CR). CR uses a novel lighting model to create photorealistic images with excellent anatomic detail for improved depiction of the extent of traumatic aortic injuries. Four patients with acute traumatic aortic injury identified on thoracic CT angiography were analyzed by creating standard 3D volume-rendered reconstructions and CR images on an independent 3D workstation. In this series of four patients, we present the typical patterns of aortic injury imaging findings and complications associated with traumatic aortic injury, with an emphasis on the utilization of the novel 3D technique of CR. CR can provide realistic imaging of the thoracic aortic contour with excellent spatial details. This methodology allows for an accurate assessment of aortic injury and optimal preoperative planning in patients with traumatic thoracic aortic injury.

Incidence of persistent metopic suture in Australia: findings from 1034 three-dimensional computed tomography scans.

To investigate the incidence of persistent, open metopic sutures in contemporary Australians aged 24months and older. Metopic suture evaluation was conducted on retrospective cranial/cervical computed tomography scans of patients aged 24 to 252months who presented to the Women's and Children's Hospital in Adelaide, Australia, between 2010 and 2020. Suture ossification was graded according to Lottering scoring system based on 4 stages, on three-dimensional volume-rendered reconstructions (stage 1: fibrous tissue interface, stage 2: commenced fusion, stage 3: complete fusion and stage 4: obliterated suture). The complete persistent sutures were classified as stage 1. Partially closed sutures were classified into stages 2 and 3, while completely closed sutures were defined as stage 4. One thousand thirty-four patients (61.2% male and 38.8% female) were included, with a mean age at scan of 66months. More than half of patients were subject to scanning due to closed-head injuries. The incidence of persistent (completely open) metopic suture was 4.8% (2.3% in males and 2.5% in females). In comparison, a partially closed metopic suture was found in 6.3% of the study cohort, with the remaining sutures located along the metopic suture line, at the glabella, mid-part of the suture, bregma and glabella-bregma areas. The prevalence of persistent metopic sutures in our study of the Australian population is 4.8%, and it is equally distributed between the genders. The pattern of suture closure can commence from any location along the suture line, which is in contrast to the existing literature.

Fusion patterns of minor lateral calvarial sutures on volume-rendered CT reconstructions

OBJECTIVESeveral years ago, the authors treated an infant with sagittal and bilateral parietomastoid suture fusion. This made them curious about the normal course of fusion of “minor” lateral sutures (sphenoparietal, squamosal, parietomastoid). Accordingly, they investigated fusion of these sutures on 3D volume-rendered head CT reconstructions in a series of pediatric trauma patients.METHODSThe authors reviewed all volume-rendered head CT reconstructions obtained from 2010 through mid-2012 at Children’s Hospital Colorado in trauma patients aged 0–21 years. Each sphenoparietal, squamosal, and parietomastoid suture was graded as open, partially fused, or fused. In several individuals, one or more lateral sutures were fused atypically. In these patients, the cephalic index (CI) and cranial vault asymmetry index (CVAI) were calculated. In a separately reported study utilizing the same reconstructions, 21 subjects had fusion of the sagittal suture. Minor lateral sutures were assessed, including these 21 individuals, excluding them, and considering them as a separate subgroup.RESULTSAfter exclusions, 331 scans were reviewed. Typically, the earliest length of the minor lateral sutures to begin fusion was the anterior squamosal suture, often by 2 years of age. The next suture to begin fusion—and first to complete it—was the sphenoparietal. The last suture to begin and complete fusion was the parietomastoid. Six subjects (1.8%) had posterior (without anterior) fusion of one or more squamosal sutures. Six subjects (1.8%) had fusion or near-complete fusion of one squamosal and/or parietomastoid suture when the corresponding opposite suture was open or nearly open. The mean CI and CVAI values in these subjects and in age- and sex-matched controls were normal and not significantly different. No individuals had a fused parietomastoid suture with open squamosal and/or sphenoparietal sutures.CONCLUSIONSFusion and partial fusion of the sphenoparietal, squamosal, and parietomastoid sutures is common in children and adolescents. It usually does not represent craniosynostosis and does not require cranial surgery. The anterior squamosal suture is often the earliest length of these sutures to fuse. Fusion then spreads anteriorly to the sphenoparietal suture and posteriorly to the parietomastoid. The sphenoparietal suture is generally the earliest minor lateral suture to complete fusion, and the parietomastoid is the last. Atypical patterns of fusion include posterior (without anterior) squamosal suture fusion and asymmetrical squamosal and/or parietomastoid suture fusion. However, these atypical fusion patterns may not lead to atypical head shapes or a need for surgery.

Longitudinal Assessment of COVID-19 Using a Deep Learning-based Quantitative CT Pipeline: Illustration of Two Cases.

HomeRadiology: Cardiothoracic ImagingVol. 2, No. 2 PreviousNext Images in Cardiothoracic ImagingFree AccessPulmonary ImagingLongitudinal Assessment of COVID-19 Using a Deep Learning–based Quantitative CT Pipeline: Illustration of Two CasesYukun Cao, Zhanwei Xu, Jianjiang Feng, Cheng Jin, Xiaoyu Han, Hanping Wu, Heshui Shi Yukun Cao, Zhanwei Xu, Jianjiang Feng, Cheng Jin, Xiaoyu Han, Hanping Wu, Heshui Shi Author AffiliationsFrom the Department of Radiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China (Y.C., X.H., H.S.); Hubei Province Key Laboratory of Molecular Imaging, Wuhan, China (Y.C., X.H., H.S.); Department of Automation, Tsinghua University, Beijing, China (Z.X., J.F., C.J.); and Department of Radiology, Michigan Medicine, University of Michigan, Ann Arbor, Mich (H.W.).Address correspondence to H.S. (e-mail: [email protected]).Yukun CaoZhanwei XuJianjiang FengCheng JinXiaoyu HanHanping WuHeshui Shi Published Online:Mar 23 2020https://doi.org/10.1148/ryct.2020200082MoreSectionsPDF ToolsImage ViewerAdd to favoritesCiteTrack CitationsPermissionsReprints ShareShare onFacebookTwitterLinked In Coronavirus disease 2019, COVID-19, has recently gained global proportions (1–3). This short report illustrates the use of voxel-level deep learning–based CT segmentation of pulmonary opacities (4) for improving quantification of the disease. A separate set of CT images from 10 cases of COVID-19 confirmed by real-time reverse transcriptase polymerase chain reaction test results was selected for training purposes. Expert manual segmentation of the lungs and pulmonary opacities was used as reference. A convolutional neural network based on U-Net architecture (5) was developed to predict the expert segmentation. We used this pipeline to analyze the contrasting evolution of two confirmed cases of COVID-19 from Wuhan, China, that were receiving similar supportive therapy. Figure 1 shows the favorable evolution of a 48-year-old woman imaged at four time points across an interval of 16 days, while Figure 2 shows the case of a 44-year-old man with disease progression over 12 days, especially between the second and third studies. These examples illustrate the potential of deep learning–based quantitative CT for providing objective assessment of pulmonary involvement and therapy response in COVID-19, but further studies are still necessary to determine the performance of such an approach in this scenario.Figure 1: Evolution of COVID-19 in a 48-year-old woman across 16 days of treatment. A, Axial unenhanced chest CT images at four time points (dates annotated in each panel) show peripheral ground-glass opacities and consolidation. B, Color overlay of voxel-level segmentation at the same level and time points as in A show pulmonary opacities displayed in yellow and normal lung in blue. C, Coronal reconstructions at the same time points as in A show progressive improvement of the lung opacities. D, Three-dimensional volume-rendered reconstructions at the same time points as in A show pulmonary opacities displayed in yellow, normal lung and vessels in light gray, and tracheobronchial tree in green. The volumetric assessment of the pulmonary opacities derived from the deep learning–based quantitative CT analysis is annotated at different time points on the volume-rendered images. LOV = lung opacification volume.Figure 1:Download as PowerPointOpen in Image Viewer Figure 2: Evolution of COVID-19 in a 44-year-old man across 12 days of treatment. A, Axial unenhanced chest CT images at four time points (dates annotated in each panel) show a small nodular opacity in the right upper lobe on the initial CT, progressing to a larger area of ground-glass opacity and consolidation, especially at time points 2 and 3. B, Color overlay of voxel-level segmentation at the same level and time points as in A show pulmonary opacities displayed in yellow and normal lung in blue. C, Coronal reconstructions at the same time points as in A show progression of the lung opacities, especially across first and third time points. D, Three-dimensional volume-rendered reconstructions at the same time points as in A show pulmonary opacities displayed in yellow, normal lung and vessels in light gray, and tracheobronchial tree in green. The volumetric assessment of the pulmonary opacities derived from the deep learning–based quantitative CT analysis is annotated at different time points on the volume-rendered images. LOV = lung opacification volume.Figure 2:Download as PowerPointOpen in Image Viewer Disclosures of Conflicts of Interest: Y.C. disclosed no relevant relationships. Z.X. disclosed no relevant relationships. J.F. disclosed no relevant relationships. C.J. disclosed no relevant relationships. X.H. disclosed no relevant relationships. H.W. disclosed no relevant relationships. H.S. disclosed no relevant relationships.Keywords: Adults, CT, Infection, Lung, Thorax Authors declared no funding for this work.

Fusion patterns of major calvarial sutures on volume-rendered CT reconstructions.

Recently, the authors investigated the normal course of fusion of minor lateral calvarial sutures on "3D" volume-rendered head CT reconstructions in pediatric trauma patients. While evaluating these reconstructions, they found many more fused sagittal sutures than expected given the currently accepted prevalence of sagittal craniosynostosis. In the present study, using the same set of head CT reconstructions, they investigated the course of fusion of the sagittal as well as the lambdoid, coronal, and metopic sutures. They reviewed all volume-rendered head CT reconstructions performed in the period from 2010 through mid-2012 at Children's Hospital Colorado for trauma patients aged 0-21 years. Each sagittal, lambdoid, coronal, or metopic suture was graded as open, partially fused, or fused. The cephalic index (CI) was calculated for subjects with fused and partially fused sagittal sutures. After exclusions, 331 scans were reviewed. Twenty-one subjects (6%) had fusion or partial fusion of the sagittal suture. Four of the 21 also had fusion of the medial lambdoid and/or coronal sutures. In the 17 subjects (5%) with sagittal suture fusion and no medial fusion of adjacent sutures, the mean CI was 77.6. None of the 21 subjects had been previously diagnosed with craniosynostosis. Other than in the 21 subjects already mentioned, no other sagittal or lambdoid sutures were fused at all. Nor were other coronal sutures fused medially. Coronal sutures were commonly fused inferiorly early during the 2nd decade of life, and fusion progressed superiorly and medially as subjects became older; none were completely fused by 18 years of age. Fusion of the metopic suture was first seen at 3 months of life; fusion was often not complete until after 2 years. The sagittal and lambdoid sutures do not usually begin to fuse before 18 years of age. However, more sagittal sutures are fused before age 18 than expected given the currently accepted prevalence of craniosynostosis. This finding is of unknown significance, but likely many of them do not need surgery. The coronal suture often begins to fuse inferiorly early in the 2nd decade of life but does not usually complete fusion before 18 years of age. The metopic suture often starts to fuse by 3 months of age, but it may not completely fuse until after 2 years of age.

Assessing the fusion of the ischiopubic synchondrosis using predictive modeling.

Flaring of the ischiopubic synchondrosis at the time of fusion is a common clinical observation in pediatrics and represents a normal physiological process in skeletal maturation. When presenting unilaterally, this flaring can mimic a range of serious pathological conditions such as osteomyelitis, osteal tumors, and traumatic injury. An improved understanding of ischiopubic synchondrosis fusion is therefore critical to avoid potential misdiagnosis. Retrospective multi-slice computed tomography pelvic scans of Australian individuals aged neonate to 24 years (n = 184) were assessed using a novel five stage morphological classification system of the maturation and fusion of the ischiopubic synchondrosis. Maturation scoring was conducted using both multiplanar formatting views and volume-rendered reconstructions in OsiriX™. Maturational stage was strongly related to age (P < 0.001) with fusion of the ischiopubic synchondrosis observed between the ages of 4 and 9 years in females and 7 and 13 years for males. The highest probability of fusion in our Queensland Australian population based on multinomial regression predictive modeling was between 7 and 10 years of age. We documented three variants of fusion: pubic and ischial outgrowths, appearance of a secondary ossification center, and a fusiform-shaped enlargement. This study provides the first predictive modeling of the timing of fusion of the ischiopubic synchondrosis using a reliable morphological classification system. The significant variation in timing and progression of fusion of the ischiopubic synchondrosis reported in this study, will aid in minimizing misdiagnosis and unnecessary treatment in children presenting with asymmetrical or delayed ischiopubic synchondrosis anomalies. Clin. Anat. 32:851-859, 2019. © 2019 Wiley Periodicals, Inc.

Emergency and Trauma of the Pelvic Ring.

Pelvic ring fractures are a common consequence of high-energy blunt trauma with a high rate of morbidity and mortality due to associated injuries, especially to the head, pelvic viscera, and vascular structures. The Young and Burgess classification system is the most widely utilized for categorizing pelvic ring injuries and assessing stability. The initial identification of these injuries often comes from an anteroposterior radiograph; however, computed tomography examination with three-dimensional volume-rendered reconstructions represents the reference standard and has essentially eliminated the requirement for inlet and outlet views. The appropriate treatment depends on a good knowledge of the anatomy and biomechanics of the pelvis. This review article underlines the importance of the integrity of ligaments to pelvic stability and describes the patterns of pelvic ring injuries and their associated mechanisms of injury.

Apophyseal Ossification of the Iliac Crest in Forensic Age Estimation: Computed Tomography Standards for Modern Australian Subadults.

This study contrasts the ontogeny of the iliac crest apophysis using conventional radiography and multislice computed tomography (MSCT), providing probabilistic information for age estimation of modern Australian subadults. Retrospective abdominopelvic MSCT data acquired from 524 Australian individuals aged 7-25 and surveillance radiographs of adolescent idiopathic scoliosis patients included in the Paediatric Spine Research Group Progression Study (n=531) were assessed. Ossification scoring of pseudo-radiographs and three-dimensional (3D) volume-rendered reconstructions using Risser (1958) quantitative descriptors indicate discrepancies in age estimates, stage allocation, and conflicting morphological progression. To mitigate visualization limitations associated with two-dimensional radiographs, we provide and validate a modified 3D-MSCT scoring tier of ossification, demonstrating complete fusion between 17.3-19.2 and 17.1-20.1years in males and females. Legal demarcation for doli incapax presumption and age of majority (18years) can be achieved using probability estimates from a fitted cumulative probit model for apophyseal fusion using the recalibrated standards.

Multivessel Transradial Percutaneous Coronary Angioplasty in a Single Coronary Artery Originating from the Right Sinus of Valsalva

Percutaneous coronary intervention in patients with an anomalous coronary artery is technically challenging. Selective cannulation and coaxial positioning in the anomalous artery and optimum stability during the procedure are pivotal for successful completion of the procedure. Selection of the appropriate guide catheter is of paramount importance in these situations. In patients with congenital coronary artery anomalies, increasing use of multidetector computed tomography for cardiac imaging may yield diagnostic information not obtained with coronary angiography. Axial, multiplanar, and three-dimensional volume-rendered reconstructions aid in detecting and interpreting such anomalies and in selecting appropriate hardware during percutaneous coronary intervention in these patients. We report a case of successful stent implantation in the right coronary artery and proximal circumflex coronary artery in a patient with a single coronary artery arising from the right sinus of Valsalva.

Multidetector computed tomography in nonmalignant laryngeal disease

Multidetector computed tomography (MDCT) is the examination of choice for laryngeal imaging in benign and malignant lesions. This review gives an overview of the MDCT scanning technique and discusses the advantages and disadvantages in investigation of benign lesions of the larynx. MDCT is not the primary diagnostic method for benign lesions on the vocal folds. However, CT is indispensable for the diagnostic investigation of immobility of the vocal fold, for laryngoceles, and for laryngeal trauma, and may allow the exact delineation of extension and nature of benign laryngeal disease. The improved spatial resolution with consecutive high-quality two-dimensional (2D) and three-dimensional (3D) reconstructions using thin-slice MDCT allows a better detection of laryngeal anatomic structures and benign pathologies. The investigation of choice in diagnosing the cause of hoarseness is laryngoscopy and/or laryngostroboscopy, respectively. Nevertheless, thin-slice MDCT with multiplanar 2D and 3D volume-rendered reconstructions is essential for exact anatomic definition and extension and diagnosis of subtle benign laryngeal diseases.

Coronary artery anatomy and variants

Variants and congenital anomalies of the coronary arteries are usually asymptomatic, but may present with severe chest pain or cardiac arrest. The introduction of multidetector CT coronary angiography (MDCT-CA) allows the detection of significant coronary artery stenosis. Improved performance with isotropic spatial resolution and higher temporal resolution provides a valid alternative to conventional coronary angiography (CCA) in many patients. MDCT-CA is now considered the ideal tool for three-dimensional visualization of the complex and tortuous anatomy of the coronary arteries. With multiplanar and volume-rendered reconstructions, MDCT-CA may even outperform CCA in determining the relative position of vessels, thus providing a better view of the coronary vascular anatomy. The purpose of this review is to describe the normal anatomy of the coronary arteries and their main variants based on MDCT-CA with appropriate reconstructions.

Computed tomography for detection and postoperative imaging of the left anterior descending artery occlusion incompletely visualized by conventional angiography

Fig. 1. LAO angiographic view failing to visualize the accurate course of distal LAD (black arrowheads) (A). CT curved multiplanar reconstruction demonstrating clearly the distal segment of LAD (B). Cx: circumflex artery; Dg: diagonal branch; LAD: left anterior descending artery. Fig. 2. CT sagittal maximum intensity projection performed 12 months after surgical revascularization confirmed good patency of the left internal mammary artery jump graft to the LAD (A). 3D volume-rendered reconstruction showing patent arterial jump graft to the LAD, first diagonal branch and second obtuse marginal branch (B). 3D volume-rendered reconstructions demonstrating non-stenotic anastomotic site to the LAD (C and D). LAD: left anterior descending artery; LIMA: left internal mammary artery.

Epidemiology, imaging, and treatment of Lisfranc fracture-dislocations revisited

The purpose of this article is to discuss the features of Lisfranc injuries and identify their typical imaging findings on radiographs, CT, and MR imaging. Lisfranc injuries are most often caused by hyperplantarflexion of the foot, often during a sporting injury or in high-speed motor vehicle collisions. The most common radiographic findings include diastasis of the base of the first and second metatarsals and the "fleck" sign, though neither is necessarily present in every Lisfranc fracture-dislocation. Owing to their often subtle radiographic presentation, clinically suspected Lisfranc injuries warrant imaging with a more sensitive test for the detection of osseous and ligamentous Lisfranc injuries. 3D CT imaging provides a comprehensive evaluation of the injury for optimal treatment planning, with resultant decreased long-term patient morbidity. Furthermore, 3D volume-rendered CT and CT multiplanar reconstructions (MPRs) provide osseous and neurovascular anatomic detail that may be a considerable help with surgical planning for operative cases of Lisfranc injuries. Also, with 3D CT and MPRs, other occult fractures, which are common in patients with high-energy injury and multiple trauma, may become evident.

Stylohyoid Complex Syndrome

To describe stylohyoid complex syndrome (SHCS) as a new diagnostic classification of all lateral neck and/or facial pain conditions resulting from an elongated styloid process, ossified stylohyoid ligament, or elongated hyoid bone. All of these pathologic conditions result in tension and reduced distensibility of the stylohyoid complex (SHC), with resultant irritation of the surrounding cervical structures with movement of the complex. A retrospective medical chart review was performed to identify a cohort of patients who underwent surgical intervention for lateral neck and/or facial pain due to pathologic SHCS. Follow-up time of greater than 1 year is reported in 5 of 7 patients. Tertiary, academic referral center. Patients included were those given a diagnosis of SHCS who underwent surgical intervention from June 2006 through September 2009. There were 7 patients, 5 of whom were female. The age range was 38 to 53 years at time of presentation (mean age, 45.3 years). Common presenting complaints were lateral neck and oropharyngeal pain exacerbated by tongue and head movements. The pathologic areas were surgically addressed through transoral or cervical approaches. Symptoms following surgical intervention. Seven patients (8 sides) were identified as having SHCS. Computed tomographic findings included elongated styloid processes (3 sides), ossified stylohyoid ligaments (2 sides), and elongated hyoid bones (3 sides). Computed tomographic scan, frequently with volume-rendered 3-dimensional reconstructions, identified the pathologic condition. All patients experienced clinically significant relief of presenting symptoms following surgical intervention. Stylohyoid complex syndrome includes all lateral neck and/or facial pain conditions resulting from an elongated styloid process, ossified stylohyoid ligament, or elongated hyoid bone. Surgical intervention directed at any pathologic point to disrupt this complex relieves tension and offers patients relief of symptoms.

The Type 4 DIEA: A Newly Identified Branching Pattern of the Deep Inferior Epigastric Artery

Sir: The deep inferior epigastric artery (DIEA) is a reliable vessel used routinely as the basis for DIEA perforator flaps, with anatomical variations infrequent and operative success widespread.1 Although the perforating branches of the DIEA may show significant individual variability in size, location, and course, the DIEA itself has been shown to be ever present as a vascular pedicle and highly dependable.1–3 Despite this consistency, the DIEA exhibits a variable branching pattern as it ascends cranially within the rectus sheath, with this pattern classified by Moon and Taylor in 1988 (Fig. 1) into three patterns: a single trunk (type 1), a bifurcating trunk (type 2), or trifurcating trunk (type 3).4Fig. 1.: Schematic diagrams of the original classification system of the branching patterns of the DIEA by Moon and Taylor. The DIEA is shown as a single, bifurcating, or trifurcating trunk below the umbilicus. The arcuate line is dotted. These schematics present the findings of the original study by Moon and Taylor. (Reproduced from Moon HK, Taylor GI. The vascular anatomy of rectus abdominis musculocutaneous flaps based on the deep superior epigastric system. Plast Reconstr Surg. 1988;82:815–829.)Previous studies assessing this anatomy have been limited by both postmortem analysis and the number of available cadaveric specimens; however, with the widespread use of preoperative imaging before abdominal wall free flaps, particularly with computed tomographic angiography, this anatomy has become routinely visualized in large numbers.5 We describe a unique case in which four major DIEA trunks were identified, suggesting a new addition to the current nomenclature. A 42-year-old woman presented for delayed autologous breast reconstruction following previous mastectomy for breast cancer. She underwent routine preoperative imaging with computed tomographic angiography, using a standardized protocol as reported previously.5 She had a body mass index in the normal range and had not undergone any previous abdominal surgery. Three-dimensional volume-rendered technique reconstructions of the computed tomographic angiograms were performed to demonstrate the DIEA, its branching pattern, and its communications. Multiple images were assessed to confirm major branches. The scan demonstrated bilateral DIEAs originating from the external iliac artery as a single trunk on each side. Although the left side ascended cranially as a single trunk (a type 1 branching pattern), the right side branched into four major branches above the arcuate line (Fig. 2). This finding does not fit the previous classification system by Moon and Taylor, but by extension would be classified as a “type 4” pattern.Fig. 2.: Computed tomographic angiogram, volume-rendered technique reconstruction of the anterior abdominal wall vasculature. The DIEA on the right side is shown to divide into four major trunks (type 4). The left-sided DIEA ascends as a single trunk (type 1).The DIEA is a consistent vessel supplying the lower anterior abdominal wall integument. Originating from the external iliac artery, the artery pierces the transversalis fascia to enter the rectus sheath. After supplying two large branches, a pubic branch that may represent an accessory obturator artery and an early muscular branch to the rectus abdominis, the artery ascends within the rectus sheath to display a variable branching pattern before anastomosing with branches of the deep superior epigastric artery. The Moon and Taylor nomenclature was the first such classification system described. Although this system describes three branching patterns of the DIEA, either a single, bifurcating, or trifurcating trunk,4 the current case highlights a fourth branching pattern. These variations in the branching pattern of the DIEA can have a significant impact on the surgical approach to DIEA perforator flap harvest, with perforators arising from a single branch preferred. Such an approach can spare rectus abdominis muscle damage, preserve vascular supply, and potentially spare motor nerve damage where a medial branch is harvested. DISCLOSURE The authors have no conflicts of interest to disclose. Warren M. Rozen, M.B.B.S., B.Med.Sc., P.G.Dip.Surg.Anat., Ph.D. Mark W. Ashton, M.B.B.S., M.D. Damien Grinsell, M.B.B.S. Jack Brockhoff Reconstructive Plastic Surgery Research Unit Department of Anatomy and Cell Biology University of Melbourne Parkville, Victoria, Australia

Role of MDCT coronary angiography in the evaluation of septal vs interarterial course of anomalous left coronary arteries

Conventional coronary angiography (CCA) may be inaccurate to distinguish between interarterial and septal subtypes of anomalous left coronary arteries (CAs). We compared the classification of anomalous left CA arising from the right sinus of Valsalva (RSV) or right CA on the basis of multidetector computed tomography coronary angiography (MDCTCA) with the classification derived from CCA. A retrospective review of 6000 consecutive electrocardiographic-gated MDCTCAs identified 15 cases of anomalous left main or left anterior descending CA arising from the RSV or right CA coursing between the aorta and the main pulmonary artery. On the basis of MDCTCA findings, the proximal course of each vessel was classified into 3 subtypes: 1, interarterial; 2, septal; and 3, mixed. CCA was reviewed in 5 cases (33%) and classified according to traditional criteria. When CCA images were not available, 3-dimensional volume-rendered reconstructions were used to simulate CCA. On the basis of MDCTCA, subtypes were distributed as type 1 (n = 2), type 2 (n = 4), and type 3 (n = 8). One case could not be classified into any of these subtypes and was classified as type 4, right ventricular infundibulum (RVI). Applying CCA criteria, 2 cases would have been classified as interarterial and 14 as septal without appreciation of the mixed or RVI subtypes. Classification of anomalous left CAs into either septal or interarterial may be too simplistic. There is an anatomic spectrum of anomalous left CAs detected by MDCTCA that challenges the traditional classification based on CCA.

Morphological Suitability of Patients With Aortoiliac Aneurysms for Endovascular Preservation of the Internal Iliac Artery Using Commercially Available Iliac Branch Graft Devices

To quantify the proportion of patients with morphology suitable for the use of a commercially available iliac branch graft device (IBD), which offers an endovascular alternative to avoid the morbidity of internal iliac artery (IIA) embolization during endovascular aneurysm repair (EVAR) of aortoiliac aneurysms. A retrospective single-center study was conducted of 51 patients (44 men; mean age 75+/-7 years) undergoing IIA embolization (36 unilateral, 15 bilateral) prior to EVAR between June 2005 and August 2009. Three-dimensional volume-rendered reconstructions of computed tomographic angiography (CTA) scans were compared to criteria published by experienced surgeons and to manufacturer's instructions for use (IFU). Morphological suitability for IBD was graded with a score reflecting 15 variables (morphological score) extracted from the IFU and publications from experienced endovascular centers. The higher the score, the more adverse morphological features were encountered. In the 51 patients, 66 target IIAs were studied. Of these, 25 (38%) target IIAs with a mean morphological score 4.44+/-1.96 were compliant with the manufacturer's IFU. Nineteen (29%) target IIA were compliant with experienced surgeons' criteria, with a mean morphological score of 4.2+/-2.0. The most common adverse feature was an aneurysmal IIA. In a population of patients with aortoiliac aneurysms, morphological applicability of a commercially available IBD was low, with the majority of patients possessing at least 1 adverse anatomical feature. A validated morphological scoring system derived from registry-type data is needed, with quantification of outcomes in IBD deployment that extends the IFU.

Preoperative Computed Tomographic Angiography for Deep Inferior Epigastric Artery Perforator Flaps: Important Information for the Reporting Radiologist

Sir: The use of preoperative imaging for perforator flaps with computed tomographic angiography is being increasingly sought by reconstructive surgeons internationally. This has been particularly sought before the deep inferior epigastric artery perforator flap, where imaging with computed tomographic angiography has been shown to reduce operating times and improve operative outcomes.1,2 However, there are significant differences in the scanning protocol and the techniques for reconstruction for abdominal wall computed tomographic angiography compared with routine abdominal computed tomographic angiography that require implementation. Without these changes, perforators are not adequately imaged, venous and soft-tissue contamination occurs, and the images are not suitable for surgical correlation. In recent visits by the current authors to multiple international centers, it has become apparent that although the scanning protocols have been instituted adequately, the interpretation of the scan data has been less than could otherwise be achieved. The three-dimensional reconstruction of scan data is essential for accurate interpretation, perforator mapping, and presentation to the surgeon. In our previous publications on the use of preoperative computed tomographic angiography, we have described the scanning technique that we use to optimize visualization of perforators.3–5 In terms of positioning the patient, this consists of maintaining the patient in the operative position (supine), without compressive clothing, and scanning the range of the flap only (pubic symphysis to 4 cm above the umbilicus). The scanning protocol involves triggering the contrast bolus at the common femoral artery and scanning the patient in the caudocranial direction (to match filling of the deep inferior epigastric artery). The three-dimensional image reconstructions are the most important part of postscan processing. We use two major techniques: volume-rendered technique reconstructions are used for mapping the cutaneous course of perforators, and maximum intensity projection reconstructions are used for assessing the intramuscular course of perforators.4 Volume-rendered technique reconstructions require the use of a color look-up table, and we have developed a color look-up table that optimally displays the subfascial and subcutaneous course of perforators and highlights the location at which perforators pass through the anterior rectus sheath. This color look-up table is designed to make subcutaneous fat completely transparent, maximize the surface contours of the rectus sheath, and color the skin pink to allow structures to be distinguished from each other. We have found use of this color look-up table to be an essential component of reviewing these scans. The color look-up table can be implemented by using the data shown in Figure 1, or by downloading our color look-up table from the free-to-use Web site (http://insideinspace.com/). Alternatively, the color look-up table or other details can be requested by e-mailing the corresponding author.Fig. 1.: Color look-up table and ray cast lighting properties in Siemens Syngo InSpace 4D (Syngo InSpace 4D, version 2006A; Siemens Medical Solutions, Erlangen, Germany).Although volume-rendered technique images (using our color look-up table) are optimized for visualizing the subcutaneous and subfascial course of perforators (Fig. 2, above), the intramuscular course is optimally seen with maximum intensity projection reconstructions. We use thick axial maximum intensity projection images (both thick contiguous 20/20-mm and thick overlapping 50/20-mm maximum intensity projection images) to demonstrate the intramuscular course of the perforators (Fig. 2, below).Fig. 2.: Computed tomographic angiogram of the abdominal wall vasculature. (Above) Volume-rendered technique reconstruction showing the cutaneous course of a 2-mm periumbilical perforator (arrow). (Below) Maximum intensity projection reconstruction showing the intramuscular course of the same perforator (arrow).The use of these techniques for image reconstruction can drastically improve the benefits of preoperative computed tomographic angiography and can be readily implemented by involving an interested radiology department. Without these finer details of scanning technique and processing, the imaging can frequently be misleading and inadequate. Warren M. Rozen, M.B.B.S., B.Med.Sc. Jack Brockhoff Reconstructive Plastic Surgery Research Unit Department of Anatomy and Cell Biology The University of Melbourne Timothy J. Phillips, M.B.B.S. Damien L. Stella, M.B.B.S. Department of Radiology Royal Melbourne Hospital Mark W. Ashton, M.B.B.S., M.D. Jack Brockhoff Reconstructive Plastic Surgery Research Unit Department of Anatomy and Cell Biology The University of Melbourne Parkville, Victoria, Australia