Beth Ripley

Scan, plan, print, practice, perform: Development and use of a patient-specific 3-dimensional printed model in adult cardiac surgery

Objective: Static 3‐dimensional printing is used for operative planning in cases that involve difficult anatomy. An interactive 3D print allowing deliberate surgical practice would represent an advance. Methods: Two patients with hypertrophic cardiomyopathy had 3‐dimensional prints constructed preoperatively. Stereolithography files were generated by segmentation of chest computed tomographic scans. Prints were made with hydrogel material, yielding tissue‐like models that can be surgically manipulated. Septal myectomy of the print was performed preoperatively in the simulation laboratory. Volumetric measures of print and patient resected specimens were compared. An assessment tool was developed and used to rate the utility of this process. Clinical and echocardiographic data were reviewed. Results: There was congruence between volumes of print and patient resection specimens (patient 1, 3.5 cm3 and 3.0 cm3, respectively; patient 2, 4.0 cm3 and 4.0 cm3, respectively). The prints were rated useful (3.5 and 3.6 on a 5‐point Likert scale) for preoperative visualization, planning, and practice. Intraoperative echocardiographic assessment showed adequate relief of left ventricular outflow tract obstruction (patient 1, 80 mm Hg to 18 mm Hg; patient 2, 96 mm Hg to 9 mm Hg). Both patients reported symptomatic improvement (New York Heart Association functional class III to class I). Conclusions: Three‐dimensional printing of interactive hypertrophic cardiomyopathy heart models allows for patient‐specific preoperative simulation. Resection volume relationships were congruous on both specimens and suggest evidence of construct validity. This model also holds educational promise for simulation of a low‐volume, high‐risk operation that is traditionally difficult to teach.

Impact of Three-Dimensional Printing on the Study and Treatment of Congenital Heart Disease.

Three-dimensional (3D) printing technology allows for the translation of a 2-dimensional medical imaging study into a physical replica of a patient’s individual anatomy. 3D printed models can facilitate a deeper understanding of complex patient anatomy and can aid in presurgical decision-making.1 Although there are 3D printing case reports in almost every subspecialty of medicine to date, the rate of adoption in the field of congenital heart disease (CHD) is particularly advanced.2,3 This is due, in no small part, to the fact that the heart is a hollow organ, which makes it a perfect substrate for 3D printing. More importantly, medical decision-making in CHD is informed by assessment of the anatomic morphology of the heart because cardiac pathology is a direct manifestation of the underlying 3D structure. Reports on the application of 3D printing in the study and treatment of CHD are accumulating rapidly; these studies cover uses, including advanced visualization, surgical planning, and education.4 Individual case reports and small studies indicate the potential to improve patient outcomes using patient-specific 3D models. There is a growing body of literature that demonstrates the value of 3D models in decision-making,5 procedural planning,5–7 and postoperative care simulation.8,9 Two specific cases are illustrated for the reader’s interest in Figures 1 and 2. Figure 1. After surgical repair of a superior sinus venosus defect and anomalous pulmonary venous drainage, a 4-year-old girl was found to have a long-segment stenosis of the superior vena cava (SVC) as it entered the right atrium, anterior to the right upper pulmonary venous baffle. A 3-dimensional (3D) printed model created from the magnetic resonance imaging (MRI) data more clearly demonstrated the relationship of the SVC stenosis to the right upper pulmonary vein baffle, giving operators the confidence to proceed with …

3D printing from MRI Data: Harnessing strengths and minimizing weaknesses.

3D printing facilitates the creation of accurate physical models of patient‐specific anatomy from medical imaging datasets. While the majority of models to date are created from computed tomography (CT) data, there is increasing interest in creating models from other datasets, such as ultrasound and magnetic resonance imaging (MRI). MRI, in particular, holds great potential for 3D printing, given its excellent tissue characterization and lack of ionizing radiation. There are, however, challenges to 3D printing from MRI data as well. Here we review the basics of 3D printing, explore the current strengths and weaknesses of printing from MRI data as they pertain to model accuracy, and discuss considerations in the design of MRI sequences for 3D printing. Finally, we explore the future of 3D printing and MRI, including creative applications and new materials.

Principles of three-dimensional printing and clinical applications within the abdomen and pelvis

Improvements in technology and reduction in costs have led to widespread interest in three-dimensional (3D) printing. 3D-printed anatomical models contribute to personalized medicine, surgical planning, and education across medical specialties, and these models are rapidly changing the landscape of clinical practice. A physical object that can be held in one’s hands allows for significant advantages over standard two-dimensional (2D) or even 3D computer-based virtual models. Radiologists have the potential to play a significant role as consultants and educators across all specialties by providing 3D-printed models that enhance clinical care. This article reviews the basics of 3D printing, including how models are created from imaging data, clinical applications of 3D printing within the abdomen and pelvis, implications for education and training, limitations, and future directions.

Initial Clinical Experience with Dual-Agent Relaxation Contrast for Isolated Lymphatic Channel Mapping

Purpose To evaluate the clinical performance of dual-agent relaxation contrast (DARC) magnetic resonance (MR) lymphangiography compared with that of conventional MR lymphangiography in the creation of isolated lymphatic maps in patients with secondary lymphedema. Materials and Methods This retrospective study was approved by the institutional review board. The diagnostic quality of 42 DARC MR lymphangiographic studies was compared with that of 42 conventional MR lymphangiographic studies. Two independent readers rated venous contamination as absent, mild, or moderate to severe. Interreader agreement on venous contamination grades was assessed by using the linearly weighted Cohen κ statistic. The Mann-Whitney U test was used to compare the distribution of grades at each station between conventional MR lymphangiography and DARC MR lymphangiography for each reader separately. Results DARC MR lymphangiography had significantly less venous contamination than did conventional MR lymphangiography (P < .001). The two radiologists rated venous contamination as moderate to severe in 64% (27 of 42) and 69% (29 of 42) of distal limbs, 23% (10 of 42) of midlimbs, and 2% (one of 42) and 9% (four of 42) of proximal limbs at conventional MR lymphangiography compared with 0% (0 of 42) of distal limbs, 2% (one of 42) of midlimbs, and 0% (0 of 42) of proximal limbs at DARC MR lymphangiography. Lymphatic signal was partially attenuated (median 45% decrease) when longer echo times were used for venous suppression, but it did not subjectively degrade diagnostic quality. Conclusion DARC MR lymphangiography yields isolated lymphatic maps through nulling of venous contamination, thereby simplifying diagnostic interpretation and communication with surgical colleagues.

No free lunch: Even with a diet heavy on PEARS

5. Rodriguez S. The real reason everyone calls billion-dollar startups ‘unicorns.’ International Business Times. Available at: http://www.ibtimes.com/real-reasoneveryone-calls-billion-dollar-startups-unicorns-2079596. Accessed March 3, 2017. 6. Ioannidis JP. Stealth research and Theranos: reflections and update 1 year later. JAMA. 2016;316:389-90. 7. PlebaniM. Evaluating and using innovative technologies: a lesson from Theranos? Clin Chem Lab Med. 2015;53:961-2.

Use of a 3D-Printed Abdominal Compression Device to Facilitate CT Fluoroscopy–Guided Percutaneous Interventions

OBJECTIVE The purpose of this article is to describe a handheld external compression device used to facilitate CT fluoroscopy-guided percutaneous interventions in the abdomen. CONCLUSION The device was designed with computer-aided design software to modify an existing gastrointestinal fluoroscopy compression device and was constructed by 3D printing. This abdominal compression device facilitates access to interventional targets, and its use minimizes radiation exposure of radiologists. Twenty-one procedures, including biopsies, drainage procedures, and an ablation, were performed with the device. Radiation dosimetry data were collected during two procedures.

MDCT of the Chest Wall

Muti-row-detector CT (MDCT) is the primary modality for evaluation of both congenital and acquired chest wall disorders. Imaging data from MDCT examinations provide anatomical detail and delineate relationships between adjacent structures. Three-dimensional reconstructions from the raw data can be used to enhance visualization of complex three-dimensional (3D) anatomy and for volumetric quantification to aid in surgical planning. This chapter illustrates the technical and practical considerations of utilizing MDCT in the evaluation of chest wall lesions, tumors, infections, and trauma and highlights MDCT advances in surgical planning, including 4D imaging and three-dimensional modeling and printing.