Differences in radiation dose for computed tomography of the brain among pediatric patients at the emergency departments: an observational study.

BACKGROUND: Computed tomography (CT) is associated with a risk of cancer development. Strategies to reduce radiation doses vary between centers. We compared radiation doses of CT brain studies between pediatric and general emergency departments (EDs), and determine the proportion studies performed within the reference levels recommended by the International Commission on Radiological Protection (ICRP). METHODS: A retrospective review was carried out in a healthcare network consisting of one pediatric ED and three general hospital EDs. Pediatric patients less than 16 years old with CT brain studies performed between 1 January 2015 and 31 December 2018 were included. Information on demographic, diagnosis, volume-averaged computed-tomography dose index and dose length product (DLP) were collected. Effective dose was then calculated from DLP using conversion factors, termed k-coefficients which were derived using a 16 cm head CT dose phantom. RESULTS: Four hundred and seventy-nine CT brain studies were performed - 379 (79.1%) at the pediatric ED. Seizure (149, 31.1%), head injury (147, 30.7%) and altered mental status (44, 9.2%) were the top three ED diagnoses. The median effective dose estimates were higher in general than pediatric EDs, particularly for those aged > 3 to ≤6 years old [1.57 mSv (IQR 1.42-1.79) versus 1.93 mSv (IQR 1.51-2.28), p = 0.047], > 6 to ≤10 years old [1.43 mSv (IQR 1.27-1.67) versus 1.94 mSv (IQR 1.61-2.59), p = 0.002) and > 10 years old (1.68 mSv (IQR 1.32-1.72) versus 2.03 mSv (IQR 1.58-2.88), p < 0.001). Overall, 233 (48.6%) and 13 (2.7%) studies were within the reference levels recommended by ICRP 60 and 103 respectively. CONCLUSIONS: Radiation doses for CT brain studies were significantly higher at general EDs and less than half of the studies were within the reference levels recommended by ICRP. The development of diagnostic reference levels (DRLs) as a benchmark and clinical justification for performing CT studies can help reduce the radiation risks in the pediatric population.

Persistent primitive trigeminal artery associated with a cavernous carotid aneurysm. Case report and literature review.

The persistent primitive trigeminal artery is the most common persistent carotid-vertebrobasilar anastomosis. Patients are usually asymptomatic and the persistent primitive trigeminal artery is commonly found incidentally on imaging. Rarely, they may present with symptoms of neurovascular conflict or cranial nerve compression syndromes as the artery may be intimately related to the cranial nerves. The basilar artery is often hypoplastic in this condition and blood supply to the posterior circulation is predominantly via the persistent primitive trigeminal artery. Recognizing the persistent primitive trigeminal artery is imperative as disease of the artery may result in ischemia of the posterior circulation. To date, there is no clear association between this artery and cerebral aneurysms. We present a rare case of a patient with a persistent primitive trigeminal artery and a concomitant cavernous carotid aneurysm together with a literature review.

Clinics in diagnostic imaging (170).

A 30-year-old woman presented with a six-month history of left posterior heel pain. Physical examination revealed a tender, inflamed and indurated posterior heel with a visible bony prominence of the posterosuperior aspect of the calcaneus. Lateral ankle radiography showed a prominent left posterosuperior calcaneal tuberosity and thickening of the distal Achilles tendon outline. Magnetic resonance imaging demonstrated high-signal inflammatory fluid in the retrocalcaneal bursa, increased signal intensity and thickening of the Achilles tendon, and prominence of the posterior calcaneus tuberosity with reactive marrow oedema. The findings are consistent with Haglund's deformity. The patient underwent hind foot surgery after failing a six-month course of conservative therapy. There was no further recurrence of symptoms after surgery. The clinical and radiological features of Haglund's deformity are described, including a short discussion of other causes of hind foot pain.