Observational study on the incidence of nephrogenic systemic fibrosis in patients with renal impairment following gadoterate meglumine administration: the NSsaFe study.

BACKGROUND: Nephrogenic systemic fibrosis (NSF) is a rare life-threatening condition strongly associated with the administration of gadolinium-based contrast agents in patients with severe or endstage renal impairment. PURPOSE: To prospectively determine the incidence of NSF in patients with renal impairment after administration of gadoterate meglumine. STUDY TYPE: Prospective. POPULATION: In all, 540 patients with moderate, severe, or endstage renal impairment, scheduled to undergo a routine contrast-enhanced MRI with gadoterate meglumine. Mean age was 69.7 ± 12.7 years (range: 21-95) with 58.4% of males. FIELD STRENGTH/SEQUENCE: 1.5T or 3.0T, sequence according to each site practice. ASSESSMENT: Medical history, indication(s) for current MRI and adverse events were recorded for each patient. Patients were followed up over 2 years after administration with three visits separated by at least 3 months to detect any signs/symptoms suggestive of NSF. STATISTICAL TESTS: Descriptive. RESULTS: Renal impairment was graded as moderate for 69.4% of patients, severe for 16.0% and endstage for 12.1%; 2.6% had undergone a kidney transplant. Estimated glomerular filtration rate ranged from 4 to 59 mL/min/1.73 m2 except one value of 74 mL/min/1.73 m2 in a patient with kidney transplant. Central nervous system exploration was the main MRI indication (34.7%) and mean dose injected was 0.22 ± 0.09 mL/kg. Overall, 446 patients (82.6%) attended at least one follow-up visit and completed the NSF questionnaire and 329 (60.9%) attended the 2-year visit. No suspicion of NSF was reported in all 446 patients, including 119 patients with severe or endstage renal impairment. No deaths and no adverse events were reported during the MRI examination and the usual period of follow-up after gadoterate meglumine administration. DATA CONCLUSION: No cases of NSF were observed in the 446 patients with moderate to endstage renal impairment followed up over a maximum of 2 years after injection of gadoterate meglumine. LEVEL OF EVIDENCE: 2 Technical Efficacy Stage: 4 J. Magn. Reson. Imaging 2020;51:607-614.

Observational study on the safety profile of gadoterate meglumine in 35,499 patients: The SECURE study.

PURPOSE: To investigate the safety of gadoterate meglumine and identify the incidence of nephrogenic systemic fibrosis (NSF). MATERIALS AND METHODS: An international prospective observational study was conducted from November 2008 to June 2013. A total of 35,499 adults and children who were scheduled to undergo contrast-enhanced MRI using gadoterate meglumine were analyzed (female, 53.1%; mean age: 49.5 years; range: 0-98 years). At least 3-month follow-up was planned for patients with an estimated creatinine clearance or glomerular filtration rate <60 mL/min (/1.73 m2) to detect any suspicion or occurrence of NSF. Adverse events (AEs) were prospectively recorded. Demographic data, risk factors, indications for MRI examinations, characteristics of gadoterate meglumine administration, and efficacy were documented. RESULTS: MRI examinations were mainly for central nervous system (61%). The most frequent risk factor was renal insufficiency (14.7%). Seventy AEs were observed in 44 patients (0.12%). Among the 70 AEs, 38 in 32 patients (0.09% of all patients) were considered related to gadoterate meglumine and classified as adverse drug reaction (ADR).The most frequent ADRs were urticaria (9 patients, 0.03%), nausea (7 patients, 0.02%), and vomiting (4 patients, 0.01%). Within the pediatric population (1,629 patients), only one AE (vomiting) was observed. Nine adult patients (0.03%) experienced serious AEs. Moderate to severe renal insufficiency at inclusion was reported in 514 patients (1.5%). Among them, 476 (92.6%) were followed-up. No patients were suspected of having NSF and no cases of NSF were observed. CONCLUSION: Our study confirms the excellent safety profile of gadoterate meglumine in routine practice. LEVEL OF EVIDENCE: 1 J. Magn. Reson. Imaging 2017;45:988-997.

Standard and cardiac-gated phase-contrast magnetic resonance imaging in the clinical course of patients with Chiari malformation Type I.

OBJECT: The causal treatment of Chiari malformation Type I (CM-I) consists of removing the obstruction of CSF flow at the level of the foramen magnum. Cerebrospinal fluid flow can be visualized using dynamic phase-contrast MR imaging. Because there is only a paucity of studies evaluating CSF dynamics in the region of the spinal canal on the basis of preoperative and postoperative measurements, the authors investigated the clinical usefulness of cardiacgated phase-contrast MR imaging in patients with CM-I. METHODS: Ninety patients with CM-I underwent preoperative MR imaging of CSF pulsation. Syringomyelia was present in 59 patients and absent in 31 patients. Phase-contrast MR imaging of the entire CNS was used to investigate 22 patients with CM-I before surgery and after a mean postoperative period of 12 months (median 12 months, range 3-33 months). In addition to the dynamic studies, absolute flow velocities, the extension of the syrinx, and tonsillar descent were also measured. RESULTS: The changes in pulsation were highly significant in the region of the (enlarged) cistern (p = 0.0005). Maximum and minimum velocities (the pulsation amplitude) increased considerably in the region where the syrinx was largest in diameter. The changes of pulsation in these patients were significant in the subarachnoid space in all spinal segments but not in the syrinx itself and in the central canal. CONCLUSIONS: The demonstration of CSF flow pulsation can contribute to assessments of surgical outcomes. The results presented here, however, raise doubts about current theories on the pathogenesis of syringomyelia.

Arachnoscopy: a special application of spinal intradural endoscopy.

OBJECT: The microsurgical removal of obstructions to CSF flow is the treatment of choice in the surgical management of intradural arachnoid cysts. Cardiac-gated phase-contrast MR imaging is an effective tool for the primary diagnosis and localization of arachnoid cysts. Microsurgery, however, does not lend itself to assessments of further adhesions beyond the borders of the exposed area. The use of a thin endoscope allows surgeons to assess intraoperatively whether the exposure is wide enough. METHODS: Between 2006 and 2010, a single neurosurgeon performed 31 consecutive microsurgical procedures with endoscopic assistance in 28 patients with spinal arachnoid adhesions. A MurphyScope endoscope was used for this purpose. The CSF flow was studied before and after surgery in all patients by using phase-contrast MR imaging in the region of the craniocervical junction, the cervical spine, the thoracic spine, and the lumbar spine. RESULTS: In all 31 procedures, CSF flow obstructions were detected at the level identified by phase-contrast MR imaging. In 29 procedures, image quality was sufficient for an inspection of the adjacent subarachnoid space. In 6 cases, the surgeon detected further adhesions that obstructed CSF flow in the adjacent subarachnoid space that were not visualized with the microscope. In all cases, these adhesions were identified and removed during microsurgery. CONCLUSIONS: Arachnoscopy is a helpful adjunct to microsurgery and can be performed safely and easily. It allows the surgeon to detect further adhesions in the subarachnoid space that would remain undetected by microscopy alone.

Endoscope-assisted surgery of spinal intradural adhesions in the presence of cerebrospinal fluid flow obstruction.

STUDY DESIGN: Prospective cohort study. OBJECTIVE: To investigate whether the adjunctive use of endoscopy of the subarachnoid space (arachnoscopy) can improve the success of microsurgery for spinal arachnoid adhesions. SUMMARY OF BACKGROUND DATA: Intradural adhesions that obstruct pulsatile cerebrospinal fluid (CSF) flow are a typical spinal cause of syringomyelia. Phase-contrast magnetic resonance imaging (MRI) allows CSF flow obstructions to be reliably localized. The treatment of choice is the microsurgical removal of CSF flow obstructions caused by adhesions. Microsurgery, however, does not lend itself to assessments of further adhesions beyond the borders of the exposed area. In this study, we therefore investigated whether endoscopic assistance allows adhesions in the vicinity of the exposed area to be detected. METHODS: From 2006 to 2009, a single neurosurgeon performed 27 consecutive microsurgical procedures with endoscopic assistance in 25 patients with spinal arachnoid adhesions. A MurphyScope endoscope was used for this purpose. CSF flow was studied before and after surgery in all patients using phase-contrast MRI in the region of the craniocervical junction, the cervical spine, the thoracic spine, and the lumbar spine. RESULTS: In all 27 procedures, CSF flow obstructions were detected at the level identified by phase-contrast MRI. In 25 procedures, image quality was sufficient for an inspection of the adjacent subarachnoid space. In six cases, the surgeon detected further adhesions that obstructed CSF flow in the adjacent subarachnoid space not visualized with the microscope. In all cases, these adhesions were identified and removed during microsurgery.Postoperative MRI scans demonstrated free CSF flow in all patients and a decrease in syrinx size in six patients. CONCLUSION: Arachnoscopy is a helpful adjunct to microsurgery and can be performed safely and easily. It allows the surgeon to detect further adhesions in the subarachnoid space, which would remain undetected by microscopy alone.

The mechanical response of the lumbar spine to different combinations of disc degenerative changes investigated using randomized poroelastic finite element models.

Degeneration of the intervertebral disc is related to progressive changes in the disc tissue composition and morphology, such as water loss, disc height loss, endplate calcification, osteophytosis. These changes may be present separately or, more frequently, in various combinations. This work is aimed to the biomechanical investigation of a wide range of clinical scenarios of disc degeneration, in which the most common degenerative changes are present in various combinations. A poroelastic non-linear finite element model of the healthy L4-L5 human spine segment was employed and randomly scaled to represent ten spine segments from different individuals. Six different degenerative characteristics (water loss in the nucleus pulposus and annulus fibrosus; calcification and thickness reduction of endplate cartilage; disc height loss; osteophyte formation; diffuse sclerosis) were modeled in 30 randomly generated models, 10 for each overall degree of degeneration (mild, moderate, severe). For each model, a daily loading cycle including 8 h of rest, 16 h in the standing position with superimposed two flexion-extension motion cycles was simulated. A tendency to an increase of stiffness with progressing overall degeneration was observed, in compression, flexion and extension. Hence, instability for mild degeneration was not predicted. Facet forces and fluid loss decreased with disc degeneration. Nucleus, annulus and endplate degeneration, disc height loss, osteophytosis and diffuse sclerosis all induced a statistically significant decrease in the total daily disc height variation, facet force and flexibility in flexion-extension. Therefore, grading systems for disc degeneration should include all the degenerative changes considered in this work, since all of them had a significant influence on the spinal biomechanics.

Dynamic visualization of arachnoid adhesions in a patient with idiopathic syringomyelia using high-resolution cine magnetic resonance imaging at 3T.

A 39-year-old female patient with thoracic syringomyelia underwent routine magnetic resonance imaging (MRI) and 3 T MRI to investigate the value of retrospectively cardiac-gated cine steady-state free precession (SSFP) MRI in the preoperative and postoperative diagnosis of arachnoid membranes in the spinal subarachnoid space. Therefore, 3T MRI included sagittal and transverse retrospectively cardiac-gated cine balanced fast-field echo (balanced-FFE) sequences both preoperatively and after microsurgical lysis of arachnoid adhesions and expansive duraplasty. Arachnoid membranes were detected and this result was correlated with intraoperative findings and the results of routine cardiac-gated phase-contrast cerebrospinal fluid (CSF) flow MRI. Retrospectively cardiac-gated cine SSFP MRI enabled imaging of arachnoid membranes with high spatial resolution and sufficient contrast to delineate them from hyperintense CSF preoperatively and postoperatively. The images were largely unaffected by artifacts. Surgery confirmed the presence of arachnoid adhesions in the upper thoracic spine. Not all arachnoid membranes that were seen on cine balanced-FFE sequences caused significant spinal CSF flow blockages in cardiac-gated phase-contrast CSF flow studies. In conclusion, retrospectively cardiac-gated cine SSFP MRI may become a valuable tool for the preoperative detection of arachnoid adhesions and the postoperative evaluation of microsurgical adhesiolysis in patients with idiopathic syringomyelia.