Is MRI an adequate replacement for CT scans in the three-dimensional assessment of acetabular morphology?

2018 ◽  
Vol 60 (6) ◽  
pp. 726-734 ◽  
Author(s):  
Jens Goronzy ◽  
Sophia Blum ◽  
Albrecht Hartmann ◽  
Verena Plodeck ◽  
Lea Franken ◽  
...  

Background Appropriate three-dimensional imaging of the hip joint is a substantial prerequisite for planning and performing surgical correction of deformities. Although surgeons still use computed tomography (CT), modern and fast acquisition techniques of volumetric imaging using magnetic resonance imaging (MRI) for pelvic measurements enable similar resolution. Purpose This study was designed to determine if already described measures of acetabular morphology are comparable in both techniques and if assessment can be performed with equal intra-observer and inter-observer reliability. Material and Methods Thirty-two hips (16 patients) were examined with a pelvic CT and a MRI with 3-T. Pelvic orientation was standardized by each observer in coronal, axial, and sagittal planes. Acetabular version as well as seven acetabular sector angles were measured by two observers twice with a minimum of four weeks between sessions. Results Inter-rater reliability showed excellent results for intra- and inter-rater reliability for CT (0.977–0.999) and MRI (0.969–0.998) measuring acetabular version and sector angles. Evaluating the reliability of CT and MRI for each observer revealed excellent results (0.972–0.998). Evaluating the Bland–Altman plots for intra-observer reliability showed an equal distribution of angles, within acceptable 95% limits of agreement. The same results were observed for inter-observer reliability evaluating CT and MRI as well as inter-method reliability. Conclusion Modern MRI scans are equally applicable to assess the bony pelvis as CT scans. In addition, MRI would enable the examination of soft tissues such as chondrolabral structures and muscle in the same examination. Since hip-preserving surgery is mostly conducted in younger patients, the reduction of radiation exposure is a benefit.

1997 ◽  
Vol 34 (1) ◽  
pp. 52-57 ◽  
Author(s):  
Andrew M. Mccance ◽  
James P. Moss ◽  
W. Rick Fright ◽  
Alf D. Linney

A new color-coded method of illustrating three-dimensional changes in the bone and the ratio of soft tissue to bone movement is described. The technique is illustrated by superimposing preoperative and 1-year postoperative CT scans of three patients following bimaxillary surgery. The method has proved to be a very simple, effective, and readily interpreted method of quantifying both bone and the ratio of movement of the overlying soft tissues across the face following surgery.


2020 ◽  
Vol 7 (2) ◽  
pp. 305-312
Author(s):  
Vidyadhar V Upasani ◽  
James D Bomar ◽  
Harsha Bandaralage ◽  
Joshua D Doan ◽  
Christine L Farnsworth

Abstract The purpose of this article is to report the inter- and intra-observer reliability of a computerized objective technique to quantify patient-specific acetabular morphology. We describe the use of and provide the software code for a technique to better define the location and magnitude of acetabular pathology. We have developed software code that allows the end user to obtain detailed measurements of the acetabulum using traditional computed tomography data. We provide the code and detailed instructions on how to use it in this article. The methodology was validated by having an unbiased observer (that was not involved in this project but has been trained in this software measurement methodology) to perform the entire acquisition, reconstruction and analysis procedure and compare their measurements to the measurements of one of the authors. The author then repeated the procedure 2 months later to determine intra-observer reliability. Inter- and intra-observer reliability for version, tilt, surface area and total acetabular coverage angles ranged from an intra-class correlation coefficient of 0.805 to 0.997. The method provided in this manuscript gives a reproducible objective assessment of three-dimensional (3D) acetabular morphology that can be used to assist in the diagnosis of hip pathology and to compare the morphological parameters of subjects with and without hip pathology. It allows a surgeon to understand the 3D shape of each individual’s acetabulum, share these findings with patients and their parents to demonstrate the magnitude and location of the clinical abnormality and perform patient-specific surgical corrections to optimize the shape and coverage of the hip.


2020 ◽  
pp. 146531252096701
Author(s):  
Ama Johal ◽  
Eiman Hasan ◽  
Li Fong Zou ◽  
Ferranti Wong ◽  
Shakeel Shahdad ◽  
...  

Objective: To determine whether there are differences in the facial soft tissue morphology between participants with mild (up to two) or severe (six or more) hypodontia. Design and Setting: A prospective hospital-based cohort study. Participants and Methods: Ninety-two participants, aged 11–16 years, with confirmed hypodontia were recruited. Participants were sub-grouped based on the severity (mild, two or less and severe, six or more) and distribution of the missing teeth and age. They underwent a three-dimensional (3D) optical surface scan of the facial soft tissues. Facial surface scans were compared quantitatively, applying landmark measurements and surface-based analysis. Results: In total, 92 participants, with an equal distribution between the mild (n=46) and severe (n=46) categories, were recruited. Patients with severe hypodontia displayed a reduced alar base, lower facial height, nasolabial angle ( P = 0.02) and transgonial width ( P < 0.001) compared to those with milder hypodontia. Furthermore, significant differences were observed between mild-male and severe-female groups regarding alar base, lower anterior face height and transgonial width and between mild-male and mild-female groups regarding nasolabial angle and transgonial width. Conclusion: Significant reductions were seen in the 3D soft tissue morphology of participants with severe hypodontia, in terms of the nasolabial angle, lower facial height, alar base and transgonial widths, emphasising the importance of using facial scanning as a relatively simple non-invasive method of assessment.


2020 ◽  
Vol 23 (3) ◽  
pp. 119-124
Author(s):  
Chang-Hyuk Choi ◽  
Hee-Chan Kim ◽  
Daewon Kang ◽  
Jun-Young Kim

Background: This study was performed to compare glenoid version and inclination measured using two-dimensional (2D) images from computed tomography (CT) scans or three-dimensional (3D) reconstructed bone models.Methods: Thirty patients who had undergone conventional CT scans were included. Two orthopedic surgeons measured glenoid version and inclination three times on 2D images from CT scans (2D measurement), and two other orthopedic surgeons performed the same measurements using 3D reconstructed bone models (3D measurement). The 3D-reconstructed bone models were acquired and measured with Mimics and 3-Matics (Materialise).Results: Mean glenoid version and inclination in 2D measurements were –1.705º and 9.08º, respectively, while those in 3D measurements were 2.635º and 7.23º. The intra-observer reliability in 2D measurements was 0.605 and 0.698, respectively, while that in 3D measurements was 0.883 and 0.892. The inter-observer reliability in 2D measurements was 0.456 and 0.374, respectively, while those in 3D measurements was 0.853 and 0.845.Conclusions: The difference between 2D and 3D measurements is not due to differences in image data but to the use of different tools. However, more consistent results were obtained in 3D measurement. Therefore, 3D measurement can be a good alternative for measuring glenoid version and inclination.


2021 ◽  
Vol 9 (7_suppl3) ◽  
pp. 2325967121S0009
Author(s):  
Conner Paez ◽  
James D. Bomar ◽  
Christine Farnsworth ◽  
Harsha Bandaralage ◽  
Vidyadhar Upasani

Background: Previous studies have analyzed the acetabulum in patients affected by slipped capital femoral epiphysis (SCFE), however controversy remains over how the acetabular shape may be altered in hips experiencing SCFE. In particular, changes in acetabular over-coverage and acetabular version are thought to contribute to SCFE. Hypothesis/Purpose: The purpose of this study was to determine the acetabular morphology in hips with SCFE and compare them to normally developing children. Methods: Images from patients with the diagnosis of SCFE who had a computed tomography (CT) exam of their pelvis were compared to images from an age- and sex-matched cohort of patients with CT exams of the pelvis/abdomen for a non-orthopedic related evaluation (controls). Three dimensional (3D) reconstructions were created from each CT exam (MIMICs software). Custom MATLAB software was used to uniformly align and calculate acetabular parameters from the 3D reconstructions. The acetabular parameters calculated were articular surface area, acetabular tilt, acetabular version, and acetabular coverage angles measured in a radial fashion in 5 out of 8 octants. Results: Two-hundred-ninety-eight hips were evaluated, including 67 hips with SCFE, 39 unaffected contralateral hips in patients with SCFE, and 192 normal controls. The SCFE group consisted of 33 males and 34 females. Acetabular version was similar amongst all SCFE affected hips, unaffected contralateral hips, and normal controls (p=0.575). Control hips had higher acetabular tilt than SCFE affected hips (p=0.001) and unaffected contralateral hips (p=0.012). Acetabular surface area was higher in SCFE affected hips compared to controls (p=0.003)(Table 1). SCFE affected hips had significantly increased acetabular coverage compared to controls in the superior, superior-anterior, and anterior octants (p<0.01). The unaffected contralateral sides had significantly increased acetabular coverage compared to controls in all five regions (p<0.02)(Table 2). Conclusions: Contrary to some previous studies, we did not find the acetabulum to be retroverted in hips with SCFE compared to normal hips. Both the affected and unaffected hips of SCFE patients have decreased acetabular tilt. Acetabular surface area is high in both the affected and unaffected sides in SCFE, suggesting it may be involved in the pathogenesis of the condition. There is increased acetabular coverage in the superior regions of SCFE hips. The shared morphological characteristics of both affected and unaffected sides in SCFE patients suggest that their hip anatomy may predispose them to slips. [Table: see text][Table: see text]


2020 ◽  
Vol 62 (1) ◽  
pp. 55-59
Author(s):  
Krzysztof Mataczyński ◽  
Mateusz Pelc ◽  
Halina Romualda Zięba ◽  
Zuzana Hudakova

Acquired adult flatfoot is a three-dimensional deformation, which consists of hindfoot valgus, collapse of the longitudinal arch of the foot and adduction of the forefoot. The aim of the work is to present problems related to etiology, biomechanics, clinical diagnostics and treatment principles of acquired flatfoot. The most common cause in adults is the dysfunction of the tibialis posterior muscle, leading to the lack of blocking of the transverse tarsal joint during heel elevation. Loading the unblocked joints consequently leads to ligament failure. The clinical image is dominated by pain in the foot and tibiotarsal joint. The physical examination of the flat feet consists of: inspection, palpation, motion range assessment and dynamic force assessment. The comparable attention should be paid to the height of the foot arch, the occurrence of “too many toes” sign, evaluate the heel- rise test and correction of the flatfoot, exclude Achilles tendon contracture. The diagnosis also uses imaging tests. In elastic deformations with symptoms of posterior tibial tendonitis, non-steroidal anti-inflammatory drugs, short-term immobilization, orthotics stabilizing the medial arch of the foot are used. In rehabilitation, active exercises of the shin muscles and the feet, especially the eccentric exercises of the posterior tibial muscle, are intentional. The physiotherapy and balneotherapy treatments, in particular hydrotherapy, electrotherapy and laser therapy, are used as a support. In advanced lesions, surgical treatment may be necessary, including plastic surgery of soft tissues, tendons, as well as osteotomy procedures.


2020 ◽  
Vol 27 (29) ◽  
pp. 4778-4788 ◽  
Author(s):  
Victoria Heredia-Soto ◽  
Andrés Redondo ◽  
José Juan Pozo Kreilinger ◽  
Virginia Martínez-Marín ◽  
Alberto Berjón ◽  
...  

Sarcomas are tumours of mesenchymal origin, which can arise in bone or soft tissues. They are rare but frequently quite aggressive and with a poor outcome. New approaches are needed to characterise these tumours and their resistance mechanisms to current therapies, responsible for tumour recurrence and treatment failure. This review is focused on the potential of three-dimensional (3D) in vitro models, including multicellular tumour spheroids (MCTS) and organoids, and the latest data about their utility for the study on important properties for tumour development. The use of spheroids as a particularly valuable alternative for compound high throughput screening (HTS) in different areas of cancer biology is also discussed, which enables the identification of new therapeutic opportunities in commonly resistant tumours.


Author(s):  
Jonas F. Eichinger ◽  
Maximilian J. Grill ◽  
Iman Davoodi Kermani ◽  
Roland C. Aydin ◽  
Wolfgang A. Wall ◽  
...  

AbstractLiving soft tissues appear to promote the development and maintenance of a preferred mechanical state within a defined tolerance around a so-called set point. This phenomenon is often referred to as mechanical homeostasis. In contradiction to the prominent role of mechanical homeostasis in various (patho)physiological processes, its underlying micromechanical mechanisms acting on the level of individual cells and fibers remain poorly understood, especially how these mechanisms on the microscale lead to what we macroscopically call mechanical homeostasis. Here, we present a novel computational framework based on the finite element method that is constructed bottom up, that is, it models key mechanobiological mechanisms such as actin cytoskeleton contraction and molecular clutch behavior of individual cells interacting with a reconstructed three-dimensional extracellular fiber matrix. The framework reproduces many experimental observations regarding mechanical homeostasis on short time scales (hours), in which the deposition and degradation of extracellular matrix can largely be neglected. This model can serve as a systematic tool for future in silico studies of the origin of the numerous still unexplained experimental observations about mechanical homeostasis.


Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1126
Author(s):  
Giovanna Iezzi ◽  
Francesca Di Lillo ◽  
Michele Furlani ◽  
Marco Degidi ◽  
Adriano Piattelli ◽  
...  

Symmetric and well-organized connective tissues around the longitudinal implant axis were hypothesized to decrease early bone resorption by reducing inflammatory cell infiltration. Previous studies that referred to the connective tissue around implant and abutments were based on two-dimensional investigations; however, only advanced three-dimensional characterizations could evidence the organization of connective tissue microarchitecture in the attempt of finding new strategies to reduce inflammatory cell infiltration. We retrieved three implants with a cone morse implant–abutment connection from patients; they were investigated by high-resolution X-ray phase-contrast microtomography, cross-linking the obtained information with histologic results. We observed transverse and longitudinal orientated collagen bundles intertwining with each other. In the longitudinal planes, it was observed that the closer the fiber bundles were to the implant, the more symmetric and regular their course was. The transverse bundles of collagen fibers were observed as semicircular, intersecting in the lamina propria of the mucosa and ending in the oral epithelium. No collagen fibers were found radial to the implant surface. This intertwining three-dimensional pattern seems to favor the stabilization of the soft tissues around the implants, preventing inflammatory cell apical migration and, consequently, preventing bone resorption and implant failure. This fact, according to the authors’ best knowledge, has never been reported in the literature and might be due to the physical forces acting on fibroblasts and on the collagen produced by the fibroblasts themselves, in areas close to the implant and to the symmetric geometry of the implant itself.


Author(s):  
Martina Pecoraro ◽  
Stefano Cipollari ◽  
Livia Marchitelli ◽  
Emanuele Messina ◽  
Maurizio Del Monte ◽  
...  

Abstract Purpose The aim of the study was to prospectively evaluate the agreement between chest magnetic resonance imaging (MRI) and computed tomography (CT) and to assess the diagnostic performance of chest MRI relative to that of CT during the follow-up of patients recovered from coronavirus disease 2019. Materials and methods Fifty-two patients underwent both follow-up chest CT and MRI scans, evaluated for ground-glass opacities (GGOs), consolidation, interlobular septal thickening, fibrosis, pleural indentation, vessel enlargement, bronchiolar ectasia, and changes compared to prior CT scans. DWI/ADC was evaluated for signal abnormalities suspicious for inflammation. Agreement between CT and MRI was assessed with Cohen’s k and weighted k. Measures of diagnostic accuracy of MRI were calculated. Results The agreement between CT and MRI was almost perfect for consolidation (k = 1.00) and change from prior CT (k = 0.857); substantial for predominant pattern (k = 0.764) and interlobular septal thickening (k = 0.734); and poor for GGOs (k = 0.339), fibrosis (k = 0.224), pleural indentation (k = 0.231), and vessel enlargement (k = 0.339). Meanwhile, the sensitivity of MRI was high for GGOs (1.00), interlobular septal thickening (1.00), and consolidation (1.00) but poor for fibrotic changes (0.18), pleural indentation (0.23), and vessel enlargement (0.50) and the specificity was overall high. DWI was positive in 46.0% of cases. Conclusions The agreement between MRI and CT was overall good. MRI was very sensitive for GGOs, consolidation and interlobular septal thickening and overall specific for most findings. DWI could be a reputable imaging biomarker of inflammatory activity.


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