Scimitar syndrome; report of a case

A 17-year-old woman with scimitar syndrome without an atrial septal defect was operated by intra-cardiac conduit repair. Computed tomography (CT) and magnetic resonance imaging (MRI) showed resolution images of anatomical findings of scimitar vein. Surgical procedures for the scimitar syndrome have varied according to the anatomic features presented in each case. The detection of precise anatomy of scimitar syndrome is important for determining the appropriate surgical procedure. Images of 3-dimensional (3-D) CT and MRI of scimitar syndrome were demonstrated.     

Magnetic resonance imaging assessment of airway status after orthognathic surgery.

OBJECTIVE: The purpose of this study was to determine whether orthognathic surgical procedures create significant objective postoperative airway compromise or edema. STUDY DESIGN: A pilot magnetic resonance imaging (MRI) study was performed on 10 patients undergoing orthognathic surgical procedure to determine the time of maximum postoperative swelling, optimum time for scanning, and the anatomical sites of maximum swelling. Anatomical landmarks within the upper airway were determined. A prospective clinical study was then designed to assess the amount of postoperative airway edema in 40 patients undergoing orthognathic surgical procedure at the Toronto General Hospital. All patients received standard anesthetic and postoperative care. Magnetic resonance imaging scan of the upper airway from the hard palate to the subglottis was performed to assess the cross-sectional areas and volumes 24 to 48 hours postoperatively. The anteroposterior and transverse dimensions of the airway were measured at 3 anatomical points: the hyoid bone, the arytenoid cartilages, and the cricoid cartilage. One staff neuroradiologist assessed all MRI scans. RESULTS: The study group consisted of 24 female and 16 male patients, with a range of 15 to 36 years of age, and a mean of 23 years of age. A total of 56 Le Fort I osteotomies (25 advancements, 27 impactions, and 4 extrusions) and 30 bilateral sagittal split osteotomies (13 advancements, 17 setbacks) were included. Seven patients received single-jaw surgical procedures, 16 patients received double-jaw surgical procedures, and 17 patients received double-jaw as well as chin osteotomies. There was no clinical or radiological evidence of postoperative airway edema in any of the 40 patients irrespective of the type or number of osteotomies performed. CONCLUSIONS: Orthognathic surgical procedure involving osteotomies of the maxilla, mandible, and/or chin did not cause significant airway compromise or edema in the 40 patients studied. Once patients undergoing orthognathic surgical procedure fulfill postoperative extubation criteria, they can be safely extubated.     

Editorial Commentary: Bankart Lesion in an Adolescent Athlete? Not So Fast

With the desire to remain athletically competitive, many adolescent athletes with shoulder instability are turning to early surgical invention. But is surgical repair always necessary and are all Bankart lesions identical? Using 3-dimensional, frequency-selective, fat-suppressed gradient recalled echo magnetic resonance imaging (MRI) scans, the authors noted that the anterior glenoid rim secondary ossification center peaks at age 16 years in male patients but is only fused in 70% of male patients at age 17 years. Therefore, relying on MRI alone to guide surgical treatment may result in procedures that may otherwise be avoided because normal glenoid development may be mistaken for a bony Bankart lesion. A thorough history and physical examination are still essential in adolescents with shoulder injuries. Relying on MRI alone to guide surgical treatment may result in procedures that may otherwise be avoided.     

Diagnosing,planning and evaluating osteochondral ankle defects with imaging modalities

This current concepts review outlines the role of different imaging modalities in the diagnosis, preoperative planning, and follow-up of osteochondral ankle defects. An osteochondral ankle defect involves the articular cartilage and subchondral bone (usually of the talus) and is mostly caused by an ankle supination trauma. Conventional radiographs are useful as an initial imaging tool in the diagnostic process, but have only moderate sensitivity for the detection of osteochondral defects. Computed tomography (CT) and magnetic resonance imaging (MRI) are more accurate imaging modalities. Recently, ultrasonography and single photon emission CT have been described for the evaluation of osteochondral talar defects. CT is the most valuable modality for assessing the exact location and size of bony lesions. Cartilage and subchondral bone damage can be visualized using MRI, but the defect size tends to be overestimated due to bone edema. CT with the ankle in full plantar flexion has been shown a reliable tool for preoperative planning of the surgical approach. Postoperative imaging is useful for objective assessment of repair tissue or degenerative changes of the ankle joint. Plain radiography, CT and MRI have been used in outcome studies, and different scoring systems are available.     

Imaging of postoperative complications following Ivor-Lewis esophagectomy

Postoperative imaging plays a key role in the identification of complications after Ivor-Lewis esophagectomy (ILE). Careful analysis of imaging examinations can help identify the cause of the presenting symptoms and the mechanism of the complication. The complex surgical procedure used in ILE results in anatomical changes that make imaging interpretation challenging for many radiologists. The purpose of this review was to make radiologists more familiar with the imaging findings of normal anatomical changes and those of complications following ILE to enable accurate evaluation of patients with an altered postoperative course. Anastomotic leak, gastric conduit necrosis and pleuropulmonary complications are the most serious complications after ILE. Computed tomography used in conjunction with oral administration of contrast material is the preferred diagnostic tool, although it conveys limited sensitivity for the diagnosis of anastomotic fistula. In combination with early endoscopic assessment, it can also help early recognition of complications and appropriate therapeutic management.     

Schultergelenkverletzung

Adequate imaging is mandatory for managing shoulder injuries. Radiographs in two or three different planes are an indispensable part of initial assessment, and may allow a first classification of a fracture, and the extent of degenerative changes. Helical CT with multiplanar reconstruction is helpful in deciding the appropriate surgical fixation of proximal humeral fractures. Most patients will require further diagnostic work-up for evaluating tears of the rotator cuff, labral tears, and other soft-tissue damage. MRI is established as the noninvasive diagnostic gold standard in this setting. Knowledge of anatomic details is important for interpretation of diagnostic imaging. From a legal point of view, MRI findings contribute substantial information to distinguish chronic from acute types of tendon lesions. MR arthrography allows the detection of affected soft-tissue, especially of the glenoid labrum and the glenohumeral ligaments which are associated with glenohumeral joint instability. Future studies must clarify whether dynamic imaging is helpful in providing a detailed evaluation of laxity and functional impairment of the shoulder joint.     

Konventionelle Röntgenaufnahme und konventionelle Tomografie für die Orthopädie

Although sonography, computed tomography (CT) and magnetic resonance imaging (MRI) are common tools in radiology, conventional X-rays still have a place in orthopaedic diagnostic investigation. The advantages of radiographic imaging are high local resolution concerning bone, economy of time besides relatively low costs and worldwide experience. The conventional X-ray is indispensable for planning surgical procedures and clinical monitoring. For several pathological processes an X-ray is sufficient for diagnosis and therapy (i.e. degeneration, fracture). Early changes of the bone (i.e. osteonecrosis) cannot be detected by X-ray. CT and MRI have closed the diagnostic gap. Indications for conventional tomography are rare.     

Intraoperative imaging using a mobile computed tomography scanner.

OBJECTIVE: The radicality of tumour removal in patients suffering from glioma is discussed to be an important factor for longer survival times. Therefore intraoperative imaging modalities like magnetic resonance imaging (MRI), computed tomography (CT) and ultrasound (US) are tested in many neurosurgical facilities for clinical use. In our department a mobile CT for intraoperative applications is used for this purpose since 1999. The handling and useful application of the mobile CT scanner as well as results without intraoperative imaging are discussed. MATERIAL AND METHODS: 470 CT scans with the mobile CT were accomplished, including 270 cases of neuronavigation planning, 76 cases of intraoperative scans, 48 cases of postoperative scans, 69 CT scans for stereotactic biopsy planning and control as well as 3 cases of emergency scanning in trauma patients and 4 spine applications. The results of the intraoperative CT scans are compared with those of the postoperative MRI scans. Additionally 87 patients with glioma were evaluated. These patients underwent surgery without intraoperative imaging. RESULTS: In 27 out of 43 patients with glioma residual tumour was detected with intraoperative CT. In 13 cases the surgery was resumed to complete resection, in 14 cases the operation was not continued due to close vicinity to eloquent areas or difficulties in image interpretation. In 44 cases the results of intraoperative CT and postoperative MRI were compared. In 6 cases the MRI demonstrated residual tumour in contrast to the results of the CT scans. In 3 cases the tumour removal could have been more complete (6.8 %). In 87 cases glioma surgery was performed without intraoperative CT. In 6 cases a more complete tumour removal could have been performed (6.9 %) according to the results of postoperative MRI. CONCLUSION: Intraoperative imaging with a mobile CT scanner is a good method for detection of residual tumour. The CT scanner can be integrated in an operative setting without problems. Although intraoperative imaging can be helpful in some selected cases, most of the neurosurgical procedures can be well performed with proper neuronavigation planning.     

MRI of the shoulder. Degenerative changes and rotator cuff tears

MRI currently offers the best imaging information for the diagnosis of subacromial pain syndrome, rotator cuff tears and osteoarthritis of the shoulder. The excellent anatomical and tissue specific imaging allows a detailed evaluation of the rotator cuff as well as the adjacent bony structures. If the cause of subacromial pain can not be determined despite extensive clinical, sonographical and radiological examination, MRI is indicated if there is a suspected pathology of the bony structures or the glenohumeral joint that could influence the further therapeutic procedures. In addition, MRI evaluation of muscular atrophy has become an important factor for determining appropriate therapy, particularly in cases of massive rotator cuff tears.     

Open MRI-Guided Neurosurgery

Summary  Objectives. A number of different image-guided surgical techniques have been developed during the past decade. None of these methods can provide the surgeon with information about the dynamic changes that occur intra-operatively.  Material and Method. The first vertical open 0.5 T MRI-scanner for intra-operative MRI-guided neurosurgery in Germany was installed at the University of Leipzig during the summer 1996. Since autumn 1996 a number of surgical procedures including biopsies (n=31), craniotomies (n=32), transsphenoidal procedures (n=8) and interstitial lasertherapies (n=3) have been performed using intra-operative MR image guidance.  Results. The development of MR-compatible and MR-safe non-magnetic instruments and components had to be solved. Specific surgical instruments were developed to perform biopsies, craniotomies, microsurgical tumour resections and transsphenoidal procedures in the 0.5-T open MRI. Several components required adaptation including the head holder, the stereotactic navigation device, the high speed drill, the suction unit, the ultrasonic aspirator, the bipolar coagulation, the laser probe and the surgical microscope. All these newly developed technical features enable the neurosurgeon to perform a large number of surgical procedures under direct control and guidance of intra-operative MR imaging. In contrast to frame-based for framless navigation systems, intra-operative MRI provides accurate and immediate information during the progress of surgery. These intra-operative images allow definitive localization and targeting of the lesions and accommodate anatomical changes that may occur during surgery.  Conclusion. Intra-operative MRI is helpful for navigation as well as determining of tumour margins to achieve a complete and safe resection of intracranial lesions. Complications related to the surgical procedure are reduced and the risk of neurological deterioration due to tumour removal and postoperative complications is minimized. It can be concluded that the intra-operative application of interventional MRI technology may represent a major step forward in the field of neurosurgery.     

Magnetic resonance imaging stereotactic thalamotomy: report of a case with comparison to computed tomography

The anatomical location of the thalamic target (ventrolateral nucleus) during stereotactic thalamotomy for a movement disorder was determined using magnetic resonance imaging (MRI) to define the anterior and posterior commissures and the intercommissural plane. Precise targeting was confirmed by intraoperative stereotactic computed tomography (CT), electrophysiological stimulation, and a gratifying postoperative response (disappearance of contralateral tremor and rigidity). The use of a MRI- and CT-compatible stereotactic coordinate frame allowed multiplanar imaging with excellent spatial and contrast resolution, visualization of the source of the tremor (prior embolic stroke affecting the dentatorubrothalamic pathway), and correction for the more medial location of the internal capsule in this patient. Location did not vary among target sites seen with MRI and CT imaging techniques. In this patient MRI during stereotactic thalamotomy supplemented CT and the electrophysiological technique that we conventionally use to define the ventrolateral nucleus. Although the importance of possible magnetic susceptibility imaging artifacts remains to be elucidated, stereotactic MRI may prove sufficiently accurate in the future to replace other imaging techniques used during functional neurosurgery.     

Use of preoperative advanced imaging for reverse total shoulder arthroplasty

BackgroundIn order to avoid implant related complications related to glenosphere malposition, there has been an increased interest in the use of advanced imaging, including computed tomography (CT) and magnetic resonance imaging (MRI) for preoperative planning and patient-specific instrumentation for reverse shoulder arthroplasty (RSA). While recent literature has demonstrated improved component position when this technology is applied, the clinical benefits remain largely hypothetical and unproven. Thus, the goals of the current study were to utilize a national database to describe current trends in the use of preoperative advanced imaging and investigate the relationship between such imaging and postoperative complications compared to matched controls without any preoperative imaging.MethodsPatients undergoing RSA for non-fracture indications were identified within the Mariner dataset within the PearlDiver database from 2010 to 2018Q2. Patients who underwent preoperative advanced imaging (MRI and/or CT) within a year prior to surgery were then identified as study cohorts. A matched cohort undergoing RSA without preoperative advanced imaging was created for comparison purposes. The incidence of imaging over time and rates of loosening/osteolysis, periprosthetic fracture, prosthetic dislocation, and revision shoulder arthroplasty of all groups were compared using a regression analysis.ResultsThe percentage of patients who underwent preoperative CT (141% increase, P < .0001), and either MRI or CT (107% increase, P = .002) increased significantly during the study period, while there was no significant increase in MRI utilization (P = .122). Patients who underwent preoperative CT experienced significantly lower rates of revision shoulder arthroplasty (2.4% vs. 3.3%, OR = 0.72, P = .004) and periprosthetic dislocation (2.8% vs. 3.3%, OR 0.80, P = .039) within 2 years of RSA compared to patients who did not undergo preoperative CT, while preoperative MRI was associated with significantly lower rates of periprosthetic fracture (0.2% vs. 0.4%, OR 0.44, P = .005), revision shoulder arthroplasty (2.1% vs. 2.6%, OR = 0.75, P = .006), and periprosthetic dislocation (2.5% vs. 3.2%, OR 0.78, P = .003) within 2 years of RSA compared to patients without an MRI.ConclusionThere has been a significant increase in the utilization of preoperative CT as compared to MRI for RSA during the time period studied. The utilization of preoperative advanced imaging may be associated with a statistically significant reduction in multiple implant related complications following RSA for non-fracture indications, although these findings are of unclear clinical significance given limitations of the database and low percentage difference in complication rates.Level of Evidence: Level III     

Glenoid Bone Loss in Shoulder Instability: Superiority of Three-Dimensional Computed Tomography over Two-Dimensional Magnetic Resonance Imaging Using Established Methodology

BackgroudRecent literature suggests that three-dimensional magnetic resonance imaging (3D MRI) can replace 3D computed tomography (3D CT) when evaluating glenoid bone loss in patients with shoulder instability. We aimed to examine if 2D MRI in conjunction with a validated predictive formula for assessment of glenoid height is equivalent to the gold standard 3D CT scans for patients with recurrent glenohumeral instability.MethodsPatients with recurrent shoulder instability and available imaging were retrospectively reviewed. Glenoid height on 3D CT and 2D MRI was measured by two blinded raters. Difference and equivalence testing were performed using a paired t-test and two one-sided tests, respectively. The interclass correlation coefficient (ICC) was used to test for interrater reliability, and percent agreement between the measurements of one reviewer was used to assess intrarater reliability.ResultsUsing an equivalence margin of 1 mm, 3D CT and 2D MRI were found to be different (p = 0.123). The mean glenoid height was significantly different when measured on 2D MRI (39.09 ± 2.93 mm) compared to 3D CT (38.71 ± 2.89 mm) (p = 0.032). The mean glenoid width was significantly different between 3D CT (30.13 ± 2.43 mm) and 2D MRI (27.45 ± 1.72 mm) (p < 0.001). The 3D CT measurements had better interrater agreement (ICC, 0.91) than 2D MRI measurements (ICC, 0.8). intrarater agreement was also higher on CT.ConclusionsMeasurements of glenoid height using 3D CT and 2D MRI with subsequent calculation of the glenoid width using a validated methodology were not equivalent, and 3D CT was superior. Based on the validated methods for the measurement of glenoid bone loss on advanced imaging studies, 3D CT study must be preferred over 2D MRI in order to estimate the amount of glenoid bone loss in candidates for shoulder stabilization surgery and to assist in surgical decision-making.     

Comparison of computerized tomography and magnetic resonance imaging for the postoperative assessment of residual acoustic tumor

Ten patients with surgically confirmed residual cerebellopontine angle neuromas, imaged by both computerized tomography (CT) with iodine contrast and magnetic resonance (MR) with and without gadolinium enhancement, are reviewed to identify the strengths and limitations of MR as compared with CT imaging. MR imaging offers superior anatomic resolution in multiple imaging planes without ionizing radiation, but it is expensive and has adverse effects on some patients. CT imaging offers good anatomic resolution, but in only one or two planes. CT is both less expensive and generally well tolerated, but allergy to the iodine contrast is not uncommon. The cases presented demonstrate the adequacy of CT imaging of residual tumor. However, in some cases MR imaging provided important additional detail. MR imaging also demonstrated postoperative changes within the brain stem and cerebellum. In our experience, CT imaging remains a satisfactory, unambiguous approach to the assessment of known postoperative residual cerebellopontine angle neuromas. MR imaging provides superior resolution, however, and should be used when better definition of tumor detail is needed for management decisions or when multiple follow-up scans are anticipated, so that the exposure to ionizing radiation is limited. MR is also useful to investigate postoperative neurologic dysfunction. Postoperative changes and residual tumors are more difficult to interpret on MR than on CT. Guidelines are proposed to help distinguish residual tumor from postoperative changes and scarring.     

Bildgebende Verfahren in der Diagnostik der Osteitis. Was gibt es Neues?

The diagnosis of osteitis relies on clinical evaluation of the patient, on imaging procedures such as conventional radiography, computed tomography (CT), magnetic resonance imaging (MRI) and scintigraphy,and on laboratory investigations.The basic procedure is conventional imaging combined with CT.Both modalities can be modified and combined with fistulography.The less detailed results of scintigraphic findings concerning morphologic features that can be misinterpreted as osteitis can be clarified by MRI.The decision whether an MRI study is indicated is especially important in children and in patients with involvement of the central nervous system.Choosing the appropriate imaging technique is essential for proper diagnosis of osteitis and thus for surgical intervention.     

Functional neurosurgery in the MRI environment.

OBJECTIVE: The purpose of this study was to evaluate the feasibility of microelectrode recording, electrical stimulation, and electrode position checking during functional neurosurgical procedures (DBS, lesion) in the interventional magnetic resonance imaging (iMRI) environment. METHODS: Seventy-six surgical procedures for DBS implant or radiofrequency lesion were performed in an open 0.2 T MRI operating room. DBS implants were performed in 54 patients (72 surgical procedures) and unilateral radiofrequency lesions in three for a total of 76 surgeries in 57 patients. Electrophysiological studies including macrostimulation and microelectrode recordings for localization were obtained in the 0.5 to 10 mT fringes of the magnetic field in 51 surgeries. MRI confirmation of the electrode position during the procedure was performed after electrophysiological localization. RESULTS: The magnetic field associated with the MRI scanner did not contribute significant noise to microelectrode recordings. Anatomical confirmation of electrode position was possible within the MRI artifact from the DBS hardware. Symptomatic hemorrhage was detected in two (2.6 %) patients during the operation. Image quality of the 0.2 T MRI scan was sub-optimal for anatomical localization. However, image fusion with pre-operative scans permitted excellent visualization of the DBS electrode tip in relation to the higher quality 1.5 T MRI anatomical scans. CONCLUSION: This study shows that conventional stereotactic localization, microelectrode recordings, electrical stimulation, implant of DBS hardware, and radiofrequency lesion placement are possible in the open 0.2 T iMRI environment. The convenience of having an imaging modality that can visualize the brain during the operation is ideal for stereotactic procedures.     

Assessment and treatment of glenohumeral joint deformities in children suffering from upper obstetric brachial plexus palsy

We present our approach to gleno-humeral joint deformities as sequelae from severe upper obstetric brachial plexus palsy. In 50 consecutive children with severe medial rotation contracture of the shoulder after obstetric brachial plexus palsy, we used magnetic resonance imaging to evaluate joint incongruence and dysplasia; showing frequently various deformities of the glenoid, the humeral head and pathologic changes in their relationship. The most severe deformity is true glenohumeral dysplasia. These diagnostic findings might influence our choice and technical details within surgical procedures. We actually evaluate image processing tools (segmentation software) for a better understanding of changes in anatomical structures responsible for this multifactorial joint deformity, limiting lateral and/or medial rotation of the glenohumeral joint in children with obstetric brachial plexus palsy.     

New imaging techniques in endovascular surgery.

Imaging requirements for endovascular surgery are quite different from imaging requirements for open surgical procedures. As with the entire field of endovascular surgery, imaging techniques and recommendations are changing rapidly. Preoperative imaging is crucial--once deployed, an endograft cannot be retrieved without conversion to open surgical repair. As with any surgical procedure, patient selection and preoperative planning are at least as important as technical skills and at least as difficult to learn. Nonetheless, good imaging technology is no substitute for good judgement. Endovascular procedures are also unique because intraoperative and postoperative imaging are also keys to the success of the procedure. Postoperative imaging techniques are evolving more slowly as long-term data are gathered but seem to be vitally important.