An Optimized CT Protocol for Detecting Suspected Cauda Equina Syndrome: A Comparative Analysis with MRI.

BACKGROUND AND PURPOSE: Lumbar disc herniation, potentially leading to nerve root compression and cauda equina syndrome, is typically evaluated using MR imaging. However, the limited availability of MR imaging outside regular hours in certain health care systems poses considerable challenges. This purpose of this study was to prospectively evaluate the diagnostic accuracy of an optimized CT lumbar spine protocol as a potential alternative to MR imaging in assessing suspected neural compression. MATERIALS AND METHODS: Patients presenting to the emergency department with suspected cauda equina syndrome or acute radicular symptoms secondary to lumbar disc herniation referred for MR imaging were prospectively enrolled for an additional CT optimized to assess spinal stenosis. An expert radiologist, blinded to clinical data, graded canal stenosis at each lumbar level on CT. The same grading process was applied to MR imaging after a 4-week interval to maintain blinding. RESULTS: Fifty-nine individuals were included in the final analysis. In 22 (39%) cases, no significant stenosis was identified. In a further 22 (37%) cases, disc pathology was identified that was managed conservatively. Thirteen (22%) individuals proceeded to urgent surgical decompression. In 1 (2%) instance, an alternative diagnosis was identified. Compared with MR imaging, the sensitivity, specificity, and positive and negative predictive values for CT in detecting disc pathology in patients presenting with symptoms suggestive of acute neural compression were 97% (95% CI, 82%-99%), 97% (95% CI, 83%-99%), 97% (95% CI, 92%-99%), and 97% (95% CI, 83%-99%), respectively. CT accurately identified all cases requiring urgent decompression. CONCLUSIONS: CT accurately predicted MR imaging findings in patients with suspected cauda equina and nerve root compression, demonstrating its utility as an adjunct tool for patient triage in emergency settings with limited MR imaging access. This protocol could enhance the allocation of emergency resources by appropriately selecting patients for emergent MR imaging.

What is the optimum post treatment surveillance imaging protocol for low-grade appendiceal mucinous neoplasms and pseudomyxoma peritoneii?

Appendiceal mucinous neoplasms are rare and can be associated with the development of disseminated peritoneal disease known as pseudomyxoma peritonei (PMP). Mucinous tumours identified on appendicectomy are therefore followed up to assess for recurrence and the development of PMP. In addition, individuals who initially present with PMP and are treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) are followed up to assess for recurrence. However, despite the concerted efforts of multiple expert groups, the optimal imaging follow-up protocol is yet to be established. The purpose of this article is to review the available evidence for imaging surveillance in these populations to identify the optimum post-resection imaging follow-up protocol.

SpaceOAR hydrogel distribution and early complications in patients undergoing radiation therapy for prostate cancer.

OBJECTIVES: Hydrogel spacers aim to separate the rectum from the prostate during radiation therapy for patients with prostate cancer to decrease the radiation dose and thus toxicity to the rectum. The aim of this study was to evaluate the distribution of the hydrogel spacer between the rectum and the prostate, to assess for hydrogel rectal wall infiltration and to assess for immediate complications. METHODS: Retrospective study of 160 patients who had undergone hydrogel spacer placement. Distribution of the hydrogel was assessed on MRI. MRI images were reviewed for rectal wall injection or other malplacement of gel. Early post-procedure complications were recorded. RESULTS: 117 (73.1%) patients had a symmetrical distribution of the hydrogel spacer. The mean anteroposterior rectoprostatic separation was 10.2 ± 3.7 mm (range 0-27 mm). Seven (4.3%) patient had minimal rectal wall infiltration and one (0.6%) patient had moderate infiltration. One (0.6%) patient had an intraprostatic injection of hydrogel. Two (1.3%) patients required treatment in the emergency department: one for urinary retention and one for pain. CONCLUSIONS: Transperineal hydrogel placement separates the prostate from the rectum with a symmetrical distribution in the majority of cases prior to radiation therapy with a low rate of rectal wall injection and immediate complications. ADVANCES IN KNOWLEDGE: SpaceOAR hydrogel can be safely injected into radiation naive patients with low- or intermediate-risk organ-confined prostate cancer. The spacer separates the prostate from the rectum with a symmetrical distribution in the majority of cases prior to radiation therapy.