Three-Dimensional-Printed Liver Model Helps Learners Identify Hepatic Subsegments: A Randomized-Controlled Cross-Over Trial.

INTRODUCTION: The purpose of this study was to find out whether 3-dimensional (3D)-printed models improved the learners' ability to identify liver segments. METHODS: A total of 116 physicians from 3 disciplines were tested in a cross-over trial at baseline and after teaching with 3D models and 2-dimensional (2D) images. Adjusted multilevel-mixed models were used to compare scores at baseline and after 3D and 2D. RESULTS: Accuracy in identifying hepatic segments was higher with 3D first than 2D (77% vs 69%; P = 0.05) and not significantly improved by a combination of 3D and 2D. Increased confidence in segment identification was highest in trainees after 3D (P = 0.04). DISCUSSION: 3D-printed models facilitate learning hepatic segmental anatomy.

Three-dimensional prototyping for procedural simulation of transcatheter mitral valve replacement in patients with mitral annular calcification.

INTRODUCTION: Three-dimensional (3D) prototyping is a novel technology which can be used to plan and guide complex procedures such as transcatheter mitral valve replacement (TMVR). METHODS: Eight patients with severe mitral annular calcification (MAC) underwent TMVR. 3D digital models with digital balloon expandable valves were created from pre-procedure CT scans using dedicated software. Five models were printed. These models were used to assess prosthesis sizing, anchoring, expansion, paravalvular gaps, left ventricular outflow tract (LVOT) obstruction, and other potential procedure pitfalls. Results of 3D prototyping were then compared to post procedural imaging to determine how closely the achieved procedural result mirrored the 3D modeled result. RESULTS: 3D prototyping simulated LVOT obstruction in one patient who developed it and in another patient who underwent alcohol septal ablation prior to TMVR. Valve sizing correlated with actual placed valve size in six out of the eight patients and more than mild paravalvular leak (PVL) was simulated in two of the three patients who had it. Patients who had mismatch between their modeled valve size and post-procedural imaging were the ones that had anterior leaflet resection which could have altered valve sizing and PVL simulation. 3D printed model of one of the latter patients allowed modification of anterior leaflet to simulate surgical resection and was able to estimate the size and location of the PVL after inserting a valve stent into the physical model. CONCLUSION: 3D prototyping in TMVR for severe MAC is feasible for simulating valve sizing, apposition, expansion, PVL, and LVOT obstruction.

The Various Applications of 3D Printing in Cardiovascular Diseases.

PURPOSE OF REVIEW: To highlight the various applications of 3D printing in cardiovascular disease and discuss its limitations and future direction. RECENT FINDINGS: Use of handheld 3D printed models of cardiovascular structures has emerged as a facile modality in procedural and surgical planning as well as education and communication. Three-dimensional (3D) printing is a novel imaging modality which involves creating patient-specific models of cardiovascular structures. As percutaneous and surgical therapies evolve, spatial recognition of complex cardiovascular anatomic relationships by cardiologists and cardiovascular surgeons is imperative. Handheld 3D printed models of cardiovascular structures provide a facile and intuitive road map for procedural and surgical planning, complementing conventional imaging modalities. Moreover, 3D printed models are efficacious educational and communication tools. This review highlights the various applications of 3D printing in cardiovascular diseases and discusses its limitations and future directions.

Management of pediatric hepatocellular carcinoma: A multimodal approach.

HCC is rare in the pediatric population, but is the second most common liver malignancy in children. Survival rates for primary unresectable HCC have been dismal. The objective of this study was to describe our experience with a multimodal approach for the management of unresectable HCC in two adolescent patients and to review the literature. Both patients are currently alive with no recurrence at 51 and 29 months post-transplant. Multimodality treatment involving chemotherapy with doxorubicin, cisplatin, and sorafenib; TACE; timely liver transplantation; and post-transplant therapy with sorafenib and mTOR inhibitors may help improve outcomes and prolong survival in pediatric patients with unresectable HCC.

Radiation Dose Reduction in Pediatric Body CT Using Iterative Reconstruction and a Novel Image-Based Denoising Method.

OBJECTIVE: The objective of this study was to evaluate the radiation dose reduction potential of a novel image-based denoising technique in pediatric abdominopelvic and chest CT examinations and compare it with a commercial iterative reconstruction method. MATERIALS AND METHODS: Data were retrospectively collected from 50 (25 abdominopelvic and 25 chest) clinically indicated pediatric CT examinations. For each examination, a validated noise-insertion tool was used to simulate half-dose data, which were reconstructed using filtered back-projection (FBP) and sinogram-affirmed iterative reconstruction (SAFIRE) methods. A newly developed denoising technique, adaptive nonlocal means (aNLM), was also applied. For each of the 50 patients, three pediatric radiologists evaluated four datasets: full dose plus FBP, half dose plus FBP, half dose plus SAFIRE, and half dose plus aNLM. For each examination, the order of preference for the four datasets was ranked. The organ-specific diagnosis and diagnostic confidence for five primary organs were recorded. RESULTS: The mean (± SD) volume CT dose index for the full-dose scan was 5.3 ± 2.1 mGy for abdominopelvic examinations and 2.4 ± 1.1 mGy for chest examinations. For abdominopelvic examinations, there was no statistically significant difference between the half dose plus aNLM dataset and the full dose plus FBP dataset (3.6 ± 1.0 vs 3.6 ± 0.9, respectively; p = 0.52), and aNLM performed better than SAFIRE. For chest examinations, there was no statistically significant difference between the half dose plus SAFIRE and the full dose plus FBP (4.1 ± 0.6 vs 4.2 ± 0.6, respectively; p = 0.67), and SAFIRE performed better than aNLM. For all organs, there was more than 85% agreement in organ-specific diagnosis among the three half-dose configurations and the full dose plus FBP configuration. CONCLUSION: Although a novel image-based denoising technique performed better than a commercial iterative reconstruction method in pediatric abdominopelvic CT examinations, it performed worse in pediatric chest CT examinations. A 50% dose reduction can be achieved while maintaining diagnostic quality.

Health-related quality of life in children and young adults with post-thrombotic syndrome: results from a cross-sectional study.

OBJECTIVE: While post-thrombotic syndrome (PTS) is increasingly recognized in children with a history of deep vein thrombosis (DVT), its impact on the health-related quality of life (HRQoL) is unknown. Our objective was to evaluate the association between the PTS and HRQoL by surveying a cohort of patients treated at our institution for DVT. MATERIALS/METHODS: All unique pediatric patients (0-18 years) treated for a DVT at the Mayo Clinic during the 15-year period, 1995-2009 were identified. A previously validated PTS survey instrument and age appropriate Pediatric Quality of Life inventory, version 4 (PedsQL 4.0) were mailed to eligible patients. Linear regression models were fit to compare the HRQoL scores between PTS groups (none, mild, moderate/severe), after adjusting for the presence of potential covariates. RESULTS: Of the 90 respondents, 65 (72%) reported signs and/or symptoms of PTS. Mean age (± SD) at DVT diagnosis and survey completion were 12.8 (± 6.1) and 19.3 (± 7.7) years, respectively. Self-report PedsQL 4.0 module was completed by 79 patients, and 34 guardians completed the parent-proxy module. Patients with moderate to severe PTS reported significantly worse total HRQoL score (mean ± SD, 71.3 ± 13.4) as compared to patients with mild PTS (84.8 ± 14.2) and no PTS (83.4 ± 14) (P = 0.001). CONCLUSION: Moderate to severe PTS has a significant impact on self-reported HRQoL as measured using the generic PedsQL 4.0. Further research is warranted to develop a venous disease-specific quality of life measure for children with a history of DVT.

Tips and tricks for MR angiography of pediatric and adult congenital cardiovascular diseases.

OBJECTIVE: The use of contrast-enhanced MR angiography (MRA) as an alternative to CT angiography or conventional angiography to assess pediatric and adult patients with cardiovascular diseases has the potential to significantly reduce patients' lifetime exposure to ionizing radiation. However, imaging this group of patients can be challenging because of a number of factors, including small size, difficulty timing the contrast bolus to the territory of interest, and the presence of metallic susceptibility artifact resulting from stents or clips. CONCLUSION: We present some suggestions to overcome many of these obstacles to MRA in these patients, highlighted with illustrations from clinical cases.

Neuromuscular choristoma: characteristic magnetic resonance imaging findings and association with post-biopsy fibromatosis.

OBJECTIVE: To describe imaging characteristics of neuromuscular choristomas (NMC) and to differentiate them from fibrolipomatous hamartomas (FLH). MATERIALS AND METHODS: Clinical and imaging characteristics of six patients with biopsy-proven NMC and six patients with FLH were reviewed by musculoskeletal, a pediatric, and two in-training radiologists with a literature review to define typical magnetic resonance imaging features by consensus. Five radiology trainees blinded to cases and naive to the diagnosis of NMC and a musculoskeletal-trained radiologist rated each lesion as having more than or less than 50% intralesional fat, as well as an overall impression using axial T1 images. Sensitivity, specificity, accuracy, and interobserver agreement kappa were determined. RESULTS: Typical features of NMC include smoothly tapering, fusiform enlargement of the sciatic nerve or brachial plexus elements with T1 and T2 signal characteristics closely following those of muscle. Longitudinal bands of intervening low T1 and T2 signal were often present and likely corresponded to fibrous tissue by pathology. Four of five patients with long-term follow-up (80%) developed aggressive fibromatosis after percutaneous or surgical biopsy. Nerve fascicle thickening often resulted in a "coaxial cable" appearance similar to classic FLH, however, using a cutoff of <50% intralesional fat allowed for differentiation with 100% sensitivity by all reviewers and 100% specificity when all imaging features were utilized for impressions. Agreement was excellent with all differentiating methods (kappa 0.861-1.0). CONCLUSIONS: NMC can be confidently differentiated from FLH and malignancies using characteristic imaging and clinical features. When a diagnosis is made, biopsy should be avoided given frequent complication by aggressive fibromatosis.

MR enterography in pediatric inflammatory bowel disease: retrospective assessment of patient tolerance, image quality, and initial performance estimates.

OBJECTIVE: The purpose of this article was to evaluate image quality, oral contrast administration and bowel distention, side effects, and performance estimates of MR enterography in a large cohort of pediatric patients with inflammatory bowel disease (IBD). MATERIALS AND METHODS: A retrospective analysis of the pediatric IBD clinic database (2007-2010) was performed. Eighty-five MR enterography studies in 70 patients were performed without sedation. All pediatric patients with the potential diagnosis of IBD were included, with the exception of studies performed on patients with ileoanal pouch anatomy. The quantity of ingested oral contrast material and number of adverse events were recorded. Retrospectively, image quality (including motion artifact and bowel distention) and enteric inflammation were assessed. Correlation between radiographic findings and endoscopic findings was tested by the Fisher exact test. RESULTS: Eighty-five MR enterography studies were performed without sedation in 70 patients (mean age, 15.6 years; age range, 9-18 years) over 30 months. The mean image quality for unenhanced images was significantly higher than for contrast-enhanced images (4.7 vs 4.1, p < 0.0001), with unacceptable image quality occurring on both unenhanced and contrast-enhanced sequences in one patient. The amount of oral contrast material ingested correlated with patient age (p = 0.009), with acceptable bowel distention occurring in 93% (78/85). Two patients had nausea or emesis and one experienced a syncopal episode after MR enterography. Sensitivity and specificity of MR enterography for active disease of the terminal ileum, right colon, and left colon were 80% and 85.2%, 79.1% and 77.8%, and 90.3% and 63.6%, respectively. CONCLUSION: MR enterography is feasible in patients 9 years old and older without sedation. Acceptable image quality can be achieved in nearly all patients, but a small minority will have suboptimal bowel distention or minor adverse events. Oral contrast ingestion regimes can be based on patient age. Performance estimates in children parallel reports in adults.

Workflow to develop 3D designed personalized neonatal CPAP masks using iPhone structured light facial scanning.

BACKGROUND: Continuous positive airway pressure (CPAP) is a common mode of respiratory support used in neonatal intensive care units. In preterm infants, nasal CPAP (nCPAP) therapy is often delivered via soft, biocompatible nasal mask suitable for long-term direct skin contact and held firmly against the face. Limited sizes of nCPAP mask contribute to mal-fitting related complications and adverse outcomes in this fragile population. We hypothesized that custom-fit nCPAP masks will improve the fit with less skin pressure and strap tension improving efficacy and reducing complications associated with nCPAP therapy in neonates. METHODS: After IRB approval and informed consent, we evaluated several methods to develop 3D facial models to test custom 3D nCPAP masks. These methods included camera-based photogrammetry, laser scanning and structured light scanning using a Bellus3D Face Camera Pro and iPhone X running either Bellus3D FaceApp for iPhone, or Heges application. This data was used to provide accurate 3D neonatal facial models. Using CAD software nCPAP inserts were designed to be placed between proprietary nCPAP mask and the model infant's face. The resulted 3D designed nCPAP mask was form fitted to the model face. Subsequently, nCPAP masks were connected to a ventilator to provide CPAP and calibrated pressure sensors and co-linear tension sensors were placed to measures skin pressure and nCPAP mask strap tension. RESULTS: Photogrammetry and laser scanning were not suited to the neonatal face. However, structured light scanning techniques produced accurate 3D neonatal facial models. Individualized nCPAP mask inserts manufactured using 3D printed molds and silicon injection were effective at decreasing surface pressure and mask strap pressure in some cases by more than 50% compared to CPAP masks without inserts. CONCLUSIONS: We found that readily available structured light scanning devices such as the iPhone X are a low cost, safe, rapid, and accurate tool to develop accurate models of preterm infant facial topography. Structured light scanning developed 3D nCPAP inserts applied to commercially available CPAP masks significantly reduced skin pressure and strap tension at clinically relevant CPAP pressures when utilized on model neonatal faces. This workflow maybe useful at producing individualized nCPAP masks for neonates reducing complications due to misfit.

Surgical Simulation in East, Central, and Southern Africa: A Multinational Survey.

BACKGROUND: High-income countries have increased the use of simulation-based training and assessment for surgical education. Learners in low- and middle-income countries may have different educational needs and levels of autonomy but they and their patients could equally benefit from the procedural training simulation provides. We sought to characterize the current state of surgical skills simulation in East, Central, and Southern Africa and determine residents' perception and future interest in such activities. METHODS: A survey was created via collaboration and revision between trainees and educators with experiences spanning high-income countries and low- and middle-income countries. The survey was administered on paper to 76 trainees (PGY2-3) who were completing the College of Surgeons of East, Central, and Southern Africa (COSECSA) Membership of the College of Surgeons examination in Kampala, Uganda in December 2019. Data from paper responses were summarized using descriptive statistics and frequencies. RESULTS: We received responses from 43 trainees (57%) from 11 countries in sub-Saharan Africa who participated in the examination. Fifty-eight percent of respondents reported having dedicated space for surgical skills simulation training, and most (91%) had participated in some form of simulation activity at some point in their training. However, just 16% used simulation as a regular part of training. The majority of trainees (90%) felt that surgical skills learned in simulation were transferrable to the operating room and agreed it should be a required part of training. Seventy-one percent of trainees felt that simulation could objectively measure technical skills, and 73% percent of respondents agreed that simulation should be integrated into formal assessment. However, residents split on whether proficiency in simulation should be achieved prior to operative experience (54%) and if nontechnical skills could be measured (51%). The most common cited barriers to the integration of surgical simulation into residents' education were lack of suitable tools and models (85%), funding (73%), and maintenance of facilities (49%). CONCLUSIONS: Residents from East, Central, and Southern Africa strongly agree that simulation is a valuable educational tool and ought to be required during their surgical residency. Barriers to achieving this goal include availability of affordable tools, adequate funding and confidence in the value of the educational experience. Trainees affirm further efforts are necessary to make simulation more widely available in these contexts.

Cystic changes in the ovaries of a pre-pubertal girl with Henoch-Schönlein purpura.

Henoch Schönlein Purpura is an IgA mediated vasculitis that is known to be associated with scrotal pathology. However, an association between Henoch Schönlein purpura and ovarian pathology has not been described. We present the case of a girl who developed cystic changes in her ovaries during her course of Henoch Schönlein purpura.

Coordinated approach to spinal and tracheal reconstruction in a patient with morquio syndrome.

Morquio syndrome (Mucopolysaccharidosis IVA) is an autosomal recessive lysosomal storage disease with manifestations ranging from mild to severe phenotype. Mechanical spinal cord injury and airway insufficiency are major causes of mortality. A 17-year-old male patient with severe Morquio syndrome presented with cervical and upper thoracic spinal stenosis with spinal cord myelopathy, and progressive severe tracheal stenosis. Coordinated care among otolaryngology, orthopedic surgery, neurosurgery, anesthesiology, cardiovascular surgery, radiology, and pulmonology teams facilitated the successful planning and execution of two major surgical interventions in rapid succession. This is the first description of a successful coordinated spine and airway repair in the literature.

Imaging for Acute and Chronic Scaphoid Fractures.

The scaphoid is the most commonly fractured bone in the wrist but 20% to 40% of scaphoid fractures are radiographically occult. Delayed or misdiagnosis can have significant consequences with late complications such as nonunion, malunion, or the development of avascular necrosis in the proximal pole. After initial negative radiographs, advanced cross-sectional imaging, including CT and MRI, ultimately may provide more accurate and rapid diagnosis than conventional radiography. With chronic fractures, the preferred modality depends on the clinical question. New techniques are evolving that will further advance imaging for diagnosis and treatment of scaphoid fractures.

Preoperative Planning Using 3-Dimensional Printing for Complex Paraspinal Schwannoma Resection: 2-Dimensional Operative Video.

Schwannomas are benign peripheral nerve sheath tumors that are typically round, smooth, and straightforward to resect. Occasionally they are more complicated to resect because of their size, location, degree of bony erosion, and vascular or neural compression. These complex lesions frequently require multidisciplinary surgical teams in order to decrease surgical morbidity. Historically, surgical planning consisted of imaging review and verbal communication among team members. 3-dimensional (3D) printing offers a new method for preoperative planning and is becoming more popular in Neurosurgery. This video demonstrates the use of 3D printing for complex paraspinal tumors in the cervical, thoracic, and sacral regions. The Institutional Review Board Office for Human Research Protection does not require approval for single participant case studies, or a case series with multiple participants. The subjects involved in this study were not identifiable and the general surgical consent form included permission for intraoperative photos.

3D printed modeling contributes to reconstruction of complex chest wall instability.

BACKGROUND: Three-dimensional printed models are increasingly used in many fields including medicine and surgery, but their use in the planning and execution of complex chest wall reconstruction has not been adequately described. In cases of non-union or prior attempts at chest wall reconstruction which have failed, there can be substantial deviations from expected chest wall anatomy. We report a novel technique for pre-operative planning and surgical execution of complex chest wall reconstruction, assisted by 3D printing. Our objective was to utilize 3-D volumetric modeling coupled with 3-D printing to produce patient-specific models for chest wall reconstruction in complex cases. METHODS: Soft tissue reconstruction 0.75 mm slice thickness computed tomography (CT) imaging data was loaded into medical CAD software for segmentation. Lung, muscle, foreign bodies, and bony structureswere separated due to the differences in density between them. The 3D volumetric mesh was then quality checked and stereolithography files (STL) were made which were able to be utilized by the 3D printer. The STL files were exported to a Objet 500 material jetting printer that utilized several UV light cured photopolymers. RESULTS: As an example case, we discuss a 55 year old male who underwent resuscitative thoracotomy. In the early post-operative period, he developed a pulmonary hernia in the 6th intercostal space, repaired with wire cerclage reapproximation of ribs. He developed a symptomatic mobile chest wall at the site of prior repair with additional concern for dissociated anterior cartilage. In preparation for operative repair, a 3D printed model was created, demonstrating fractured cartilage anteriorly as well a saw effect through the six and seventh ribs. An additional model was created using the normal ribs from the right side in mirror image reflection to quantify the degree and precise geometry of mal-alignment to the left chest. These models were then utilized to determine the operative approach via a thoracotomy incision to remove the cerclage wires, followed by parasternal incision, reduction and plating of the sternocostal non-union bursa Rib non-unions were plate stabilized. Repeat imaging in follow-up has demonstrated continued appropriate alignment and the patient reported improvement in his symptoms. CONCLUSION: At present, the cost of 3-D printing remains substantial, but given the improved planning in complex cases, this cost may be recaptured in the reduction of operative time and improved outcomes with reduced re-operation rates. We believe that the early adoption of this technology by surgeons can help improve surgical quality and provide enhanced individualized patient care. These patient-specific models facilitate identification of features which are often not detected with standard 3-D reconstructed CT rendering. Centers should pursue the integration of 3-D printed models into their practice and active collaborations between surgeons and modeling experts should be sought at every available opportunity.

Skull base plasmacytoma: A unique case of POEMS syndrome with a plasmacytoma causing craniocervical instability.

INTRODUCTION: Plasmacytomas, considered to be the solitary counterparts of multiple myeloma, are neoplastic monoclonal plasma cell proliferations within soft tissue or bone. Plasmacytomas often present as a collection of findings known as POEMS-syndrome (Polyneuropathy, Organomegaly, Endocrinopathy, M-Protein spike, and Skin changes). CASE DESCRIPTION: We present a report of a 47 yo male diagnosed with POEMS-syndrome secondary to a skull base plasmacytoma. The mass resulted in marked instability of the cranio-cervical junction due to bony erosion. Following an induction course of chemotherapy, he showed clinical improvement with a marked reduction in tumor size and underwent an autologous peripheral blood stem cell transplant for systemic treatment of his POEMS-syndrome. Following completion of systemic treatment, he then underwent a definitive occipital-cervical fusion without complications. His neurologic exam upon dismissal was stable with subjective improvement in left upper extremity strength. Postoperative radiographs confirmed spinal alignment and pathological examination of a small biopsy from C1 revealed benign fibrous tissue. CONCLUSION: To the best of our knowledge, this is the first report of a skull-base plasmacytoma associated with POEMS-syndrome, causing cranio-cervical instability. The approach of systemic therapy combined with temporary external fixation, followed by definitive occipital cervical fusion resulted in a good outcome for this patient.

The breadth of the diaphragm: updates in embryogenesis and role of imaging.

The diaphragm is an unique skeletal muscle separating the thoracic and abdominal cavities with a primary function of enabling respiration. When abnormal, whether by congenital or acquired means, the consequences for patients can be severe. Abnormalities that affect the diaphragm are often first detected on chest radiographs as an alteration in position or shape. Cross-sectional imaging studies, primarily CT and occasionally MRI, can depict structural defects, intrinsic and adjacent pathology in greater detail. Fluoroscopy is the primary radiologic means of evaluating diaphragmatic motion, though MRI and ultrasound also are capable of this function. This review provides an update on diaphragm embryogenesis and discusses current imaging of various abnormalities, including the emerging role of three-dimensional printing in planning surgical repair of diaphragmatic derangements.

Infraclavicular brachial plexopathy secondary to coracoid osteoid osteoma.

Coracoid osteoid osteomas are rare. This case report presents two patients with coracoid osteoid osteomas who developed neurologic sequelae of the infraclavicular brachial plexus (namely, musculocutaneous neuropathy in one patient with an anterior lesion, and suprascapular neuropathy in the other patient with a more posterior lesion). The neuropathy was due to soft tissue edema, which surrounded the bony lesion and was apparent on MRI. Surgical resection of the bony lesion in both cases produced excellent outcomes at long-term follow-up.