At 40 weeks in utero the male fetus was diagnosed with a large neck mass on prenatal ultrasound. Prenatal MR imaging was performed demonstrating a 5.7 cm by 2.7 cm left neck mass. The patient was delivered at CHOP via Caesarean section for concern of airway compromise. The baby boy required routine resuscitation and was transferred uneventfully to the neonatal intensive care unit.
On the third day of life, a neck MRI with and without gadolinium contrast was performed on the neonate, showing a T2 hyperintense, multicystic lesion with evidence of hemorrhage that extended to the posterior neck and deeper structures of the neck, including the prevertebral and retropharyngeal space, confirming a macrocystic lymphatic malformation.
This patient underwent three doxycycline sclerotherapy procedures over the course of 24 months. Doxycycline is an antibiotic that causes inflammation of the lymphatic malformation epithelium that eventually leads to scarring and regression of the lesion. The second and third sclerotherapy procedures used Low Dose syngo DynaCT imaging to confirm sclerotherapy distribution in the lesion. The syngo DynaCT was acquired with a dose value of 0.7 mGy.
syngo DynaCT is used to confirm sclerotherapy agent distribution and determine proximity to the airway in patients with complex head and neck lymphatic malformations. Intraprocedural syngo DynaCT images can provide information regarding the volume of lesion treated and the necessity for further treatment sessions. It enables us to create image reconstructions in three planes on a separate workstation allowing us to compare the extent of the lesion treated to the pre-treatment lesion in those three planes on MRI. Since this is essentially a CT scan it is imperative to achieve the lowest possible dose while preserving diagnostic information. With the inherent contrast provided by the sclerotherapy agent we are able to reduce the dose provided by our typical syngo DynaCT to 6 % of the manufacturer setting and 50 % of conventional CT. In the future, syngo DynaCT can be used to direct procedures. By identifying areas of the lesions that lack sclerotherapy agent after injection, additional injections may be performed during treatment potentially reducing the number of future sessions.
The manufacturer's default setting gave an equivalent CTDI of 4.8 mGy. Optimizing the dose settings and adding copper filtration reduced the radiation dose by 94 %. This represents a 50 % reduction from conventional CT.
Axial T2 weighted MR image demonstrating
the macrocystic lymphatic malformation left neck.
Correlating axial syngo DynaCT image demonstrating the distribution of the sclerotherapy agent throughout the lesion when compared to the MRI. Note the close proximity of the sclerotherapy agent and lesion to the airway guiding post-procedure therapy, resulting in the patient remaining intubated post-procedure.
Pediatr Radiol. 2011 Apr;41(4): 476-82. Epub 2010 Nov 16.