The Sensitivity of Limited-Sequence MRI in Identifying Pediatric Cervical Spine Injury: A Western Pediatric Surgery Research Consortium Multicenter Retrospective Cohort Study.

INTRODUCTION: Clinical clearance of a child's cervical spine after trauma is often challenging due to impaired mental status or an unreliable neurologic examination. Magnetic resonance imaging (MRI) is the gold standard for excluding ligamentous injury in children but is constrained by long image acquisition times and frequent need for anesthesia. Limited-sequence MRI (LSMRI) is used in evaluating the evolution of traumatic brain injury and may also be useful for cervical spine clearance while potentially avoiding the need for anesthesia. The purpose of this study was to assess the sensitivity and negative predictive value of LSMRI as compared to gold standard full-sequence MRI as a screening tool to rule out clinically significant ligamentous cervical spine injury. METHODS: We conducted a ten-center, five-year retrospective cohort study (2017-2021) of all children (0-18y) with a cervical spine MRI after blunt trauma. MRI images were re-reviewed by a study pediatric radiologist at each site to determine if the presence of an injury could be identified on limited sequences alone. Unstable cervical spine injury was determined by study neurosurgeon review at each site. RESULTS: We identified 2,663 children less than 18 years of age who underwent an MRI of the cervical spine with 1,008 injuries detected on full-sequence studies. The sensitivity and negative predictive value of LSMRI were both >99% for detecting any injury and 100% for detecting any unstable injury. Young children (age < 5 years) were more likely to be electively intubated or sedated for cervical spine MRI. CONCLUSION: LSMRI is reliably detects clinically significant ligamentous injury in children after blunt trauma. To decrease anesthesia use and minimize MRI time, trauma centers should develop LSMRI screening protocols for children without a reliable neurologic exam. LEVEL OF EVIDENCE: 2 (Diagnostic Tests or Criteria).

Improved depiction of subthalamic nucleus and globus pallidus internus with optimized high-resolution quantitative susceptibility mapping at 7 T.

The subthalamic nucleus (STN) and globus pallidus internus (GPi) are commonly used targets in deep-brain stimulation (DBS) surgery for the treatment of movement disorders. The success of DBS critically depends on the spatial precision of stimulation. By taking advantage of good contrast between iron-rich deep-brain nuclei and surrounding tissues, quantitative susceptibility mapping (QSM) has shown promise in differentiating the STN and GPi from the adjacent substantia nigra and globus pallidus externus, respectively. Nonlinear morphology-enabled dipole inversion (NMEDI) is a widely used QSM algorithm, but the image quality of reconstructed susceptibility maps relies on the regularization parameter selection. To date, few studies have systematically optimized the regularization parameter at the ultra-high field of 7 T. In this study, we optimized the regularization parameter in NMEDI to improve the depiction of STN and GPi at different spatial resolutions at both 3 T and 7 T. The optimized QSM images were further compared with other susceptibility-based images, including T2*-weighted (T2*w), R2*, susceptibility-weighted, and phase images. QSM showed better depiction of deep-brain nuclei with clearer boundaries compared with the other methods, and 7 T QSM at 0.35 × 0.35 × 1.0 mm3 demonstrated superior performance to the others. Our findings suggest that optimized high-resolution QSM at 7 T allows for improved delineation of deep-brain nuclei with clear and sharp borders between nuclei, which may become a promising tool for DBS nucleus preoperative localization.

Headache and Brain Tumor.

Headaches are exceedingly common, but most individuals who seek medical attention with headache will not have a serious underlying etiology such as a brain tumor. Brain tumors are uncommon; however, many patients with brain tumors do suffer from headaches. Generally these headaches are accompanied by other neurologic signs and symptoms. A careful clinical assessment for red flags should be undertaken when considering further work-up with neuroimaging to exclude a serious underlying condition.

Brain cortical structural differences between non-central nervous system cancer patients treated with and without chemotherapy compared to non-cancer controls: a cross-sectional pilot MRI study using clinically-indicated scans.

BACKGROUND: Cognitive deficit associated with cancer and its treatment is called cancer-related cognitive impairment (CRCI). Increases in cancer survival have made understanding the basis of CRCI more important. CRCI neuroimaging studies have traditionally used dedicated research brain MRIs in breast cancer survivors after chemotherapy with small sample sizes; little is known about other non-central nervous system (CNS) cancers after chemotherapy as well as those not exposed to chemotherapy. However, there may be a wealth of unused data from clinically-indicated MRIs that could be used to study CRCI. OBJECTIVE: Evaluate brain cortical structural differences in those with various non-CNS cancers using clinically-indicated MRIs. DESIGN: Cross-sectional. PATIENTS: Adult non-CNS cancer and non-cancer control (C) patients who underwent clinically-indicated MRIs. METHODS: Brain cortical surface area and thickness were measured using 3D T1-weighted images. An age-adjusted linear regression model was used and the Benjamini and Hochberg false discovery rate (FDR) corrected for multiple comparisons. Group comparisons were: cancer cases with chemotherapy (Ch+), cancer cases without chemotherapy (Ch-) and subgroup of lung cancer cases with and without chemotherapy vs C. RESULTS: Sixty-four subjects were analyzed: 22 Ch+, 23 Ch- and 19 C patients. Subgroup analysis of 16 lung cancer (LCa) patients was also performed. Statistically significant decreases in either cortical surface area or thickness were found in multiple regions of interest (ROIs) primarily within the frontal and temporal lobes for all comparisons. Effect sizes were variable with the greatest seen in the left middle temporal surface area ROI (Cohen's d -0.690) in the Ch- vs C group comparison. LIMITATIONS: Several limitations were apparent including a small sample size that precluded adjustment for other covariates. CONCLUSIONS: Our preliminary results suggest that, in addition to breast cancer, other types of non-CNS cancers treated with chemotherapy may result in brain structural abnormalities. Similar findings also appear to occur in those not exposed to chemotherapy. These results also suggest that there is potentially a wealth of untapped clinical MRIs that could be used for future CRCI studies.

Prolactin-Secreting Pituitary Carcinoma with Dural Metastasis: Diagnosis, Treatment, and Future Directions.

BACKGROUND: Pituitary carcinoma is extremely rare, representing approximately 0.2% of all surgically resected pituitary neoplasms. It is thought to arise from World Health Organization grade II (atypical) pituitary adenomas. Pituitary carcinoma is defined by metastasis; it is otherwise indistinguishable from atypical pituitary adenomas, which can be considered carcinoma in situ. Pituitary carcinoma is difficult to diagnose and treat and is associated with poor long-term outcomes. CASE DESCRIPTION: A 75-year-old man presented with a highly aggressive and treatment-refractory atypical prolactinoma that transformed into a prolactin carcinoma. Although the patient experienced early hormonal and surgical remission and local tumor control after tumor resection and fractionated radiation, isolated dural-based metastases were subsequently noted following gradual elevation in serum prolactin despite ongoing dopamine agonist therapy. En bloc resection was performed of the pathology-confirmed, prolactin-staining dural metastases. At 1-year follow-up, there was no further evidence of metastatic disease, and normalization of serum prolactin was observed. CONCLUSIONS: Long-term surveillance using serum prolactin as a tumor biomarker and correlation to imaging studies were critical for the diagnosis and interval screening for recurrence. This technique can be applied to all secretory atypical pituitary adenomas to improve early detection of potential metastasis. Further research, especially of genetic and epigenetic characteristics, could readily improve the diagnosis and treatment of pituitary carcinomas.