Aneurysmal bone cyst treated with percutaneous doxycycline: is a single treatment sufficient?

OBJECTIVE: The purpose of this case series is to report on the effectiveness of a single percutaneous injection of doxycycline as a primary treatment for aneurysmal bone cyst (ABC). MATERIALS AND METHODS: A retrospective cohort study was conducted on seven patients diagnosed with ABC at various anatomical sites, with the intention to treat by a single percutaneous injection of doxycycline. Mean patient age was 14 years. RESULTS: Signs of treatment response were seen in six of seven patients after one injection. Three of the seven received a second treatment, despite signs of response. Another had expansion of the lesion after treatment, requiring excision. In total, three patients had a single injection of doxycycline as their sole treatment and another three showed signs of response after a single injection. CONCLUSIONS: A single percutaneous injection of doxycycline should be considered a viable primary treatment option for ABC.

Multidetector computed tomography pulmonary angiography: does arm position affect pulmonary artery enhancement?

OBJECTIVE: To evaluate whether arm position affects pulmonary artery enhancement in computed tomographic pulmonary angiography (CTPA). METHODS: Study protocol had local ethics committee approval. Eighty-six patients who received 16 detector row CTPA for suspected pulmonary embolism were scanned with their contrast-injected arm resting at their side and compared with 94 patients who were scanned with both arms resting above their head. Two radiologists assessed pulmonary artery enhancement with a region-of-interest measurement of the main pulmonary artery density, scored the degree of beam-hardening artifact arising from the superior vena cava (SVC) and from the dependent arm that crossed the pulmonary arteries (1 = no artifact, 5 = artery obscured), and measured the degree of central venous compression of the injected veins at the thoracic inlet. A 2-tailed t test was performed to compare pulmonary artery density and central venous compression. RESULTS: There was no difference in pulmonary artery enhancement between the 2 arm positions. Mean density of contrast in the main pulmonary artery was 329 Hounsfield units (HU) (95% confidence interval (CI), 310-350) in the arm-down group, compared with 325 HU (95% CI, 306-346) in the arm-up group (P = 0.65). Greater compression of the central veins occurred in the arm-up group (48.5%; 95% CI, 42.3%-54.8%) than in the arm-down group (22.3%; 95% CI, 16.8%-27.8%) (P < 0.05). There was also more beam hardening arising from contrast in the SVC in the arm-up group (P < 0.0001). CONCLUSIONS: Arm position does not affect pulmonary arterial enhancement during CTPA. There was greater central venous compression and more beam-hardening artifact arising from the SVC when the arm was held above the head.