Magnetic Resonance Imaging of the Diaphragm: From Normal to Pathologic Findings (original) (raw)
Related papers
Imaging of the Diaphragm: Anatomy and Function
RadioGraphics, 2012
The diaphragm is the primary muscle of ventilation. Dysfunction of the diaphragm is an underappreciated cause of respiratory difficulties and may be due to a wide variety of entities, including surgery, trauma, tumor, and infection. Diaphragmatic disease usually manifests as elevation at chest radiography. Functional imaging with fluoroscopy (or ultrasonography or magnetic resonance imaging) is a simple and effective method of diagnosing diaphragmatic dysfunction, which can be classified as paralysis, weakness, or eventration. Diaphragmatic paralysis is indicated by absence of orthograde excursion on quiet and deep breathing, with paradoxical motion on sniffing. Diaphragmatic weakness is indicated by reduced or delayed orthograde excursion on deep breathing, with or without paradoxical motion on sniffing. Eventration is congenital thinning of a segment of diaphragmatic muscle and manifests as focal weakness. Treatment of diaphragmatic paralysis depends on the cause of the dysfunction and the severity of the symptoms. Treatment options include plication and phrenic nerve stimulation. Supplemental material available at http://radiographics .rsna.org/lookup/suppl/
Bi-parametric MRI of the Diaphragm Using Dynamic and Static Images: The Initial Experience
Curēus, 2024
Background: With recent technological advances, magnetic resonance imaging (MRI) has offered new sequences that can evaluate the real-time motion of anatomic structures. This study aims to evaluate the interobserver agreement in the diagnosis of diaphragmatic dysfunctions using bi-parametric MRI, in which dynamic sequences for diaphragm movement and static sequences for soft tissue resolution are used together to provide a visualization of the diaphragm. Methodology: Twenty-nine cases that underwent a bi-parametric magnetic resonance examination which includes coronal T2 single-shot turbo spin echo and the coronal SENSE single-shot balanced turbo field echo real-time sequences were retrospectively evaluated. The images of the patients were assessed by two independent observers. Cohen's kappa coefficient was calculated to evaluate the interobserver agreement. Results: The mean age of the patients was 44.86 ± 17.57, ranging from 18 to 80 years. The kappa value was calculated as 0.889, indicating a strong agreement between the interobservers. Conclusions: Our experience suggests that bi-parametric MRI is a promising tool in the evaluation of diaphragmatic abnormalities.
Ultrasonographic findings of the normal diaphragm: thickness and contractility
Annals of Clinical Neurophysiology, 2017
The diaphragm is the major muscle of respiration and its dysfunction is associated with problems ranging from orthopnea to prolonged recovery from surgery or ventilator management. Common causes of diaphragm dysfunction include phrenic neuropathy, motor neuron disease, neuromuscular junction disorders, and myopathy. 1-3 Although there are several diagnostic tests available for evaluating the diaphragm, each of them has limitations. 4,5 Chest x-rays are relatively insensitive. Fluoroscopy is difficult to quantitate, and, like computed tomography, involves radiation exposure and transportation need. Magnetic resonance imaging presents challenges for patients in the intensive care unit and
Functional evaluation of the diaphragm with a noninvasive test
Journal of Osteopathic Medicine, 2021
Cardiac surgery with median sternotomy causes iatrogenic damage to the function of the diaphragm muscle that is both temporary and permanent. Myocardial infarction itself causes diaphragmatic genetic alterations, which lead the muscle to nonphysiological adaptation. The respiratory muscle area plays several roles in maintaining both physical and mental health, as well as in maximizing recovery after a cardiac event. The evaluation of the diaphragm is a fundamental step in the therapeutic process, including the use of instruments such as ultrasound, magnetic resonance imaging (MRI), and computed axial tomography (CT). This article reviews the neurophysiological relationships of the diaphragm muscle and the symptoms of diaphragmatic contractile dysfunction. The authors discuss a scientific basis for the use of a new noninstrumental diaphragmatic test in the hope of stimulating research.
Radiology, 2000
Magnetic resonance (MR) imaging of the thorax with three-dimensional (3D) reconstruction and functional quantification was evaluated as a tool for structure-function evaluation of chest-wall mechanics. Good agreement was found between the corresponding spirometric and MR imaging values of lung volumes. Fast MR imaging of the thorax with 3D reconstruction should improve the ability to evaluate the inspiratory pump in clinical and research investigations.
Two-dimensional ultrasound imaging of the diaphragm: Quantitative values in normal subjects
Muscle & Nerve, 2013
Introduction: Real time ultrasound imaging of the diaphragm is an under-used tool in the evaluation of patients with unexplained dyspnea or respiratory failure. Methods: We measured diaphragm thickness and the change in thickness that occurs with maximal inspiration in 150 normal subjects, with results stratified for age, gender, body mass index, and smoking history. Results: The lower limit of normal diaphragm thickness at end expiration or functional residual capacity is 0.15 cm, and an increase of at least 20% in diaphragm thickness from functional residual capacity to total lung capacity is normal. A side to side difference in thickness at end expiration of > 0.33 cm is abnormal. Diaphragm thickness and contractility are minimally affected by age, gender, body habitus, or smoking history. Conclusions: This study confirms previous findings in much smaller groups of normal controls for quantitative ultrasound of the diaphragm and provides data that can be applied widely to the general population. 47: 884-889, 2013 Diaphragm dysfunction is an uncommon and fre-Abbreviations: EMG, electromyography; BMI, body mass index; COPD, chronic obstructive pulmonary disease
Journal of Thoracic Disease
Background: The assessment before surgical plication for unilateral hemidiaphragm (HD) eventration is not clearly defined and no precise criteria exist to really understand which patient is operated with which results depending on the technique used. The goal of this study was to evaluate the place of dynamic magnetic resonance imaging (dMRI) before and after plication by developing measurement criteria. Methods: Between 2006 and 2017, 18 patients (group1: Gp1) were operated for eventrations, 15 left-sided (Gp1L) and 3 right-sided (Gp1R). All had preoperative and postoperative evaluations including dMRI and pulmonary function tests. Five healthy volunteer subjects (group2: Gp2) had the same imaging protocol. For each HD, we measured the respiratory excursion at three fixed points (S1, S2, S3) and the height of curvature on sagittal plane. We also searched for upward paradoxical diaphragm movements. Results: Before surgery, no excursion (n=13) or extremely reduced excursion (n=5) was detected on the injured HD (IHD) in Gp1. Upward paradoxical movements were identified only in Gp1L (n=6). Compared with Gp2 subjects, the healthy HD for Gp1L patients had significantly reduced excursion values at three sites S1 (P=0.038), S2 (P=0.006), and S3 (P=0.004). After plication, the decreasing height of curvature confirmed a tightening of the IHD in all patients (median value from 100 to 39.5 mm in Gp1L and 92 to 74 mm in Gp1R, P=0.0001). All upward paradoxical movements disappeared. Healthy HD excursions in Gp1L normalised their values. All those imaging improvements were correlated with postoperative improvements of dyspnoea score (P<0.0001) and vital capacity (P=0.002). Conclusions: dMRI and the standardised grid we developed not only improve the knowledge of unilateral diaphragm eventration but also permit to evaluate the quality of its surgical repair. It also demonstrates that a dysfunction of the healthy HD contralateral to eventration is possible and reversible after plication of the IHD.
The clinical anatomy of the musculotendinous part of the diaphragm
Surgical and Radiologic Anatomy, 2015
The thoracoabdominal diaphragm is a composite musculotendinous structure, separating the thoracic and abdominal cavities. Reemphasis of the already welldelineated variations of the muscular and tendinous portions, and blood and nerve supply of the diaphragm is becoming apparent. Scientific reports concerning reconstruction of the pericardium, activation of the muscle and the phrenic nerves by use of laparoscopically placed intramuscular electrodes, and repair of congenital and traumatic hernias reemphasize the importance of the muscular to tendinous relationships. The objective of this study, therefore, was to measure the ratio of the surface area of the tendinous central region to the muscular region of the diaphragm and provide a clear description across various specimens. We classified diaphragmatic measurements from 104 adult human diaphragms into six classes (I-VI) based on the ratio of surface area between its tendinous and muscular components. The majority of specimens, 56.7 %, was attributed to class II and indicated a tendon-to-muscle ratio of between 10 and 15 %; however, a small number of specimens indicated a very large tendon area at the expense of muscle bulk. Future research should be geared toward assessing the relationship between surface area of the musculature and its motor points with focus on interventions for herniation repair and recovery. Our results have shown that surgical interventions should be tailored to the individual, as diaphragm size may not necessarily predict tendon-to-muscle ratio.
Medical Sciences, 2019
Introduction: diaphragmatic dysfunction is a common cause of slow weaning in mechanically ventilated patients. Diaphragmatic dysfunction in ventilated patients can be global or regional. The aim of our study was to evaluate the motion of the entire diaphragm in patients who were ventilated for a protracted period in comparison with healthy controls by using Magnetic Resonance Imaging (MRI). Methods: Intensive care patients who had a prolonged ventilator wean and required tracheostomies were enrolled based on extensive exclusion criteria. MRI dynamic sequence and subtraction images were used to measure vertical displacement at five different points on each hemi-diaphragm during normal tidal breathing. Tidal displacement of each point on the right and left hemi-diaphragms of the patients were compared to the precise respective points on the right and left hemi-diaphragms of enrolled controls. Results: Eight intensive care patients and eight controls were enrolled. There were observed significant differences in the displacements of the left hemi-diaphragm between the two groups (median 6.4 mm [Interquartile range (IQR), 4.6-12.5]) vs. 11.6 mm [IQR, 9.5-14.5], p = 0.02). There were also observed significant differences in the displacements at five evaluated study points on the left hemi-diaphragms of the patients when compared to the precise respective points in controls, especially at the dome (median 6.7 mm [IQR, 5.0-11.4] vs. 13.5 mm [IQR 11.5-18], p value = 0.005) and the anterior zone of apposition (median 5.0 mm [IQR, 3.3-7.1] vs. 7.8mm [IQR, 7.1-10.5], p value = 0.01). The intensive care patients showed lower minimal and maximal values of displacement of right hemi-diaphragms compared to the controls, suggesting that the differences in the displacement of right hemi-diaphragm are possible; however, the differences in the mean values of displacement of right hemi-diaphragm between the intensive care patient group and the control group (median 9.8 mm [IQR (Interquartile range), 5.0-12.3] vs. 10.1 mm [IQR 8.3-18.5], p = 0.12) did not reach the level of significance. Conclusion: Although frequently global, diaphragm dysfunction in ventilated patients after prolonged ventilation can also be regional or focal when assessed by MRI dynamic sequence. The vertical displacement of both right and left hemi-diaphragms at various anatomical locations had different values in both controls, and patients. There were significant focal variations in the movement of diaphragm in patients with ventilator-induced diaphragmatic dysfunction.
New England Journal of Medicine, 2012
he diaphragm is the dome-shaped structure that separates the thoracic and abdominal cavities. It is the principal muscle of respiration, is innervated by the phrenic nerves that arise from the nerve roots at C3 through C5, and is primarily composed of fatigue-resistant slow-twitch type I and fast-twitch type IIa myofibers. 1 Its mechanical action is best understood by considering its anatomy and its attachment to the chest wall. 2 The diaphragm abuts the lower rib cage in a region referred to as the zone of apposition (Fig. 1). As the diaphragm contracts, the abdominal contents are displaced caudally, abdominal pressure increases in the zone of apposition, and the lower rib cage expands. Disease processes that interfere with diaphragmatic innervation, contractile properties, or mechanical coupling to the chest wall can result in diaphragmatic dysfunction. 3 Such dysfunction, in turn, can lead to dyspnea, decreased exercise performance, sleep-disordered breathing, constitutional symptoms, hypersomnia, reduced quality of life, atelectasis, and respiratory failure. 4-6 This review focuses on dysfunction related to weakness and paralysis, not to anatomical abnormalities.