• Patent cranial sutures appear hyperintense on "Black Bone" MRI • Prematurely fused cranial sutures are distinct from patent sutures • Minimal soft tissue contrast permits 3D-rendered imaging of the craniofacial skeleton.

The potential harmful effects of ionising radiation continue to be highlighted. Radiation reduction techniques have largely consisted of low-dose techniques rather than a shift to non-ionising methods of imaging. CT scanning is frequently employed for imaging the craniofacial skeleton despite being one of the key anatomical regions for radiation protection in view of the radiosensitive lens and thyroid gland. We describe a low flip angle gradient echo MRI sequence which provides high image contrast between bone and other tissues but reduces the contrast between individual soft tissues. This permits the "black bone" to be easily distinguished from the uniformity of the soft tissues. While maintaining a repetition time of 8.6 ms and an echo time of 4.2 ms, the flip angle which provided optimised suppression of both fat and water was identified to be 5°. The biometric accuracy of this sequence was confirmed using a phantom to obtain direct anatomical measurements and comparable CT scanning. The average discrepancy between black bone MRI measurements and direct anatomical measurements was 0.32 mm. Black bone MRI therefore has the potential to reduce radiation exposure by replacing CT scanning when imaging the facial skeleton, with particular scope for imaging benign conditions in the young.

Both dobutamine and norepinephrine had beneficial effects on flap skin blood flow. The maximal improvement in flow occurred with norepinephrine, making it the optimal pressor to use in patients with hypotension after free flap surgery.

Dear Neuroradiology Editors, I am pleased to submit for review on behalf of myself and my co-authors the following original research paper titled "Black Bone MRI with 3D reconstruction for the Detection of Skull Fractures in Children with Suspected Abusive Head Trauma." Black bone MRI sequences are newer MRI sequences which have been developed for imaging of the bone with MRI. The purpose for this original research was to compare a black bone MRI sequence to head CT for detection of skull fractures in pediatric patients with possible abusive head trauma.

Objectives: Three-dimensionally printed anatomical models are rapidly becoming an integral part of pre-operative planning of complex surgical cases. We have previously reported the "Black Bone" MRI technique as a non-ionizing alternative to CT. Segmentation of bone becomes possible by minimizing soft tissue contrast to enhance the bone-soft tissue boundary. The objectives of this study were to ascertain the potential of utilizing this technique to produce three-dimensional (3D) printed models. Methods: "Black Bone" MRI acquired from adult volunteers and infants with craniosynostosis were 3D rendered and 3D printed. A custom phantom provided a surrogate marker of accuracy permitting comparison between direct measurements and 3D printed models created by segmenting both CT and "Black Bone" MRI data sets using two different software packages. Results: "Black Bone" MRI was successfully utilized to produce 3D models of the craniofacial skeleton in both adults and an infant. Measurements of the cube phantom and 3D printed models demonstrated submillimetre discrepancy. Conclusions: In this novel preliminary study exploring the potential of 3D printing from "Black Bone" MRI data, the feasibility of producing anatomical 3D models has been demonstrated, thus offering a potential non-ionizing alterative to CT for the craniofacial skeleton.

Background: Microvascular free tissue transfer in head and neck surgery has become an indispensable tool. Anastomotic thrombosis is one of the leading causes of flap failure; however, there are no validated methods to accurately identify and quantify those patients most at risk of thrombotic complications. The aim of this study was to determine if functional fibrinogen to platelet ratio using thrombelastography could preoperatively identify patients at risk of thrombotic complications. Materials and Methods: Twenty nine patients undergoing free tissue transfer surgery for head and neck pathology underwent routine TEG® analysis, with calculation of functional fibrinogen to platelet ratio at induction of anesthesia. All perioperative thrombotic complications were recorded and crossreferenced with preoperative ratios. Data was further compared to results obtained from 42 healthy volunteers. Results: The mean functional fibrinogen to platelet ratio was significantly higher in the surgery group compared to healthy volunteers. Of the 29 patients studied, 31% (n = 9) had some form of thrombotic event, with all but one patient having a ratio ≥42% (mean 47% ± 7%). For those patients without thrombotic events, the mean ratio was 37% ± 5%. Conclusion: A functional fibrinogen to platelet ratio above 42% as measured by TEG® may be useful in identifying those patients likely to develop thrombotic complication. © 2012 Wiley Periodicals, Inc. Microsurgery, 2012.

The squamosal suture is one of the lateral minor skull sutures, separating the parietal and squamous temporal bones. While the phenotypic appearances and sequelae of synostosis of the major cranial vault sutures are well documented, little is reported concerning synostosis of the squamosal suture (SQS). The aim of this study was to determine the frequency of squamosal suture synostosis, and to document the significance of this entity.A retrospective review of the diagnostic imaging for all new pediatric patients (aged ≤16 years) referred to the Oxford Craniofacial Unit between January 2008 and February 2013 was completed to identify patients with SQS. Computed tomography (CT) imaging was available in 422 patients and the axial and three-dimensional reconstructed images reviewed.Squamosal suture synostosis was confirmed in 38 patients (9%). It was present in conjunction with major suture synostosis in 33 patients and in isolation in 5. The incidence increased with age. It was more common in patients with syndromic craniosynostosis (18%) and associated syndromic conditions (36%) than in those with isolated major suture synostosis (6%). It was found to occur with coronal, lambdoid, and sagittal synostosis, but was most frequent with multisuture fusion patterns. Squamosal suture synostosis was not associated with a consistent calvarial deformity either in isolation or when associated with a major suture fusion. No patient underwent surgery specifically to correct SQS.In conclusion, contrary to previous reports, squamosal suture synostosis is a relatively frequent finding in the general case mix of a typical craniofacial unit, but is of limited clinical significance.

Objective: The potential risks associated with ionising radiation are well documented. We have previously reported the ''black bone'' MRI sequence, useful when imaging cortical bone. The objective of this paper is to report our initial experience of this technique in patients undergoing imaging of the head and neck region. Methods: Using the departmental database those patients having had ''black bone'' sequences of the head and neck performed as part of their MRI examination in the preceding 5 years were identified. The radiological reports were reviewed to identify those cases where ''black bone'' or conventional MRI sequences had been performed in place of the requested CT, and the patient medical records for these cases were reviewed. Medical record review was also conducted for those cases where it was considered that the pathological condition requiring imaging would ordinarily be investigated with CT. Results: The ''black bone'' sequence had been performed in 69 patients as part of routine MRI of the head and neck. Of these, 67% (n546) were performed in combination with CT imaging, the majority of cases being primary tumours. In four cases, an MRI was performed in place of the requested CT scan. We present eight clinical cases illustrating the potential benefits of the ''black bone'' sequence. Conclusions: ''Black bone'' MRI offers a radiation-free method of imaging the head and neck, and has been successfully utilised in a range of benign and malignant conditions affecting this region. Advances in knowledge: Adoption of this approach, where feasible, would be a significant advance in radiation protection.