Craniosynostosis Imaging
No Results
No Results
processing….
Craniosynostosis is the premature fusion of the cranial sutures. The condition can occur as an isolated defect or as part of a syndrome and is recognized in 2 forms: simple and compound. In simple craniosynostosis, only 1 cranial suture is involved; compound craniosynostosis involves 2 or more sutures. [1, 2] Imaging is required for the accurate diagnosis, surgical planning, post-treatment evaluation and identification of coexisting anomalies and complications associated with craniosynostosis. [3] (See the images below.)
Patients in whom craniosynostosis is suggested should undergo a careful clinical examination, with the clinician looking for abnormalities of the skull and extremities.
Plain radiography is the first radiologic step. Plain radiography quickly and simply identifies skull-shape abnormalities, which are seen in most patients with craniosynostosis. With this simple and inexpensive examination, usually all cranial sutures can be surveyed for patency.
The entire length of each suture is not always visible on plain radiographs, and some patients have only a small bony bar limiting growth at a particular suture. If the skull shape is entirely normal, craniosynostosis is unlikely.
Cranial ultrasound (CUS) is an alternative imaging modality. It offers excellent imaging of superficial structures, with the potential to confirm or exclude fusion of cranial sutures while avoiding exposure to ionizing radiation in the very young infant. The normal gap of a patent suture or the obliteration in craniosynostosis can be clearly demonstrated with CUS in children younger than 12 months. [4]
Conventional cranial computed tomography (CT) scans with bone windows or 3-dimensional (3D) CT scans are frequently obtained to confirm bony abnormalities and to delineate any associated intracranial anomalies. Three-dimensional CT is the criterion standard for the evaluation of craniosynostosis. [5, 6, 7] CT scanning is considered to be expensive and may require that the patient be sedated.
Although 3D CT has superior diagnostic value, concerns remain about the hazards of radiation exposure in infants, who are are 2 to 10 times more radiosensitive than adults. To reduce radiation dose in children, several strategies and techniques are currently available, including iterative reconstruction techniques.
Plain radiographs are obtained easily and demonstrate osseous anatomy well. At a minimum, views should include anteroposterior (AP), Townes, and bilateral lateral films. Plain radiographs are useful for identifying the abnormalities of head shape (dolichocephaly, brachycephaly, and plagiocephaly) that are characteristic of the various forms of craniosynostosis.
(See the images below.)
Plain radiographs can be used to identify prematurely fused sutures. Normal sutures are seen on plain images as serrated, nonlinear, lucent lines. Sutures in patients with craniosynostosis are usually straight with sclerotic heaped-up margins or are completely absent. The sclerotic margins may outline the sutures well and lead to the false impression that they are patent. Particular attention should be paid to the presence of this sclerotic margin and to focal sites of heaped-up margins, which are indicative of premature synostosis.
Plain radiographs can also be used to demonstrate overall morphology of the cranium and to identify the presence of localized problems (constricting bony bands restricting growth).
In addition, plain radiographs can be employed in identifying the presence of generalized problems (copper-beaten appearance, indicating elevated ICP). They can be used to identify other skeletal anomalies as well.
Visualizing the length of all sutures is not always possible, and suture closure may be difficult to detect unless it is accompanied by an abnormal head shape. Normal variations in the shape of the pediatric skull exist. For example, many formerly premature infants have long, narrow skulls resembling dolichocephaly but without sagittal synostosis. Many children also have asymmetrical flattening of the occiput caused by habitually lying on 1 side of the head, without underlying suture abnormalities; this is called positional molding. These 2 types of skull deformities are more common than craniosynostosis.
CT scans provide a more detailed method of visualizing intracranial pathology and detailed anatomy of the calvaria and brain parenchyma. In contrast to plain radiographs, the skull base is visualized well, and hard and soft tissues of the craniofacial skeleton can be studied in detail. The sensitivity of CT scans, when combined with physical examination and plain radiography, approaches 100%. Even on CT scans, the entire length of every suture may not be clearly visible, and normal variations in skull shape may pose a problem. [5, 6, 7, 8] After abnormal or suggestive plain radiographic findings are noted, CT scans with bone windows with or without 3D reconstruction are frequently requested prior to surgical therapy.
(See the images below.)
Neuroimaging is performed in children with isolated suture synostosis primarily to look for underlying brain damage or associated cerebral anomalies.
Infants with trigonocephaly may have midline anomalies (eg, holoprosencephaly).
Anomalies of the venous drainage and stenosis of the venous foramina at the skull base can occur with multisuture synostosis with syndrome- and nonsyndrome-related causes.
Features such as shallow anterior fossa, deformed dystopic orbits, abnormal calvarial contour, and asymmetrical cranial base can be realistically depicted.
In a study comparing a lowered-dose CT protocol with a standard CT protocol in children evaluated for craniosynostosis, Ernst and colleagues found the effective dose of the low dose protocol was 0.08 mSv (97% reduction). Image quality was similar to the standard protocol in overall diagnostic acceptability, objective noise measurements, subjective cranial bone edge sharpness, and presence of artefacts. For objective sharpness of cranial bone-brain interface and subjective perception of noise, the images of the low-dose protocol were superior. [9]
In a phantom study, Kaasalainen et al reported sufficient image quality using a CT protocol with an effective radiation dose of 0.02 mSv, which is comparable to the effective dose of plain radiography (approximately 0.01 mSv to 0.04 mSv). [10] Although this ultra-low-dose CT technique is not widely available and the diagnostic value for minor sutures is still questionable, these results may be promising in children with complex craniofacial malformations who undergo repeated CT scans at the time of diagnosis and at various stages of surgical correction. [3]
Danelson et al investigated the possible benefits of employing 3D models in preoperative planning for craniosynostosis surgery—specifically, spring-mediated cranioplasty and cranial vault reconstruction. [8]
MRI shows better definition of intracranial soft-tissue structures than does CT scanning. In addition, MRI is useful in the detection of hydrocephalus and cerebral developmental defects, such as myelination defects and deformities of the maxilla resulting in airway compromise. [11]
If children with craniosynostosis have abnormalities of tone or have diminished movements, MRI should be performed, because it is the most sensitive method for detecting cortical and white-matter abnormalities.
MRI is not a strong modality for evaluating bony abnormalities and thus cannot be used as the primary method of evaluating craniosynostosis. MRI is used primarily for assessing associated brainstem and soft tissue abnormalities.
Data supports cranial ultrasound (CUS) as an easy and feasible imaging technique for assessment of the cranial sutures. In a study by Linz et al, CUS confirmed a clinical diagnosis of craniosynostosis or plagiocephaly in a group of 411 infants. [12] CUS has been show to be able to differentiate fused or patent sutures effectively and differentiate nonsynostotic pathology, such as positional skull deformities and molding, from craniosynostosis. Increase of the width of the cranial sutures on serial sonograms may provide evidence for a possible increase in ICP, which is a major complication of craniosynostosis. [3]
A series of 126 infants younger than 12 months assessed for craniosynostosis with cranial ultrasound reported 100% sensitivity and 98% specificity (95% confidence interval, 94–100%) compared with 4-view radiography. [4]
Ultrasonography is user dependent, and therefore, inexperienced personnel can miss the diagnosis of craniosynostosis.
Kapp-Simon KA, Speltz ML, Cunningham ML, Patel PK, Tomita T. Neurodevelopment of children with single suture craniosynostosis: a review. Childs Nerv Syst. 2007 Mar. 23(3):269-81. [Medline].
David L, Glazier S, Pyle J, Thompson J, Argenta L. Classification system for sagittal craniosynostosis. J Craniofac Surg. 2009 Mar. 20(2):279-82. [Medline].
Kim HJ, Roh HG, Lee IW. Craniosynostosis : Updates in Radiologic Diagnosis. J Korean Neurosurg Soc. 2016 May. 59 (3):219-26. [Medline]. [Full Text].
Rozovsky K, Udjus K, Wilson N, Barrowman NJ, Simanovsky N, Miller E. Cranial Ultrasound as a First-Line Imaging Examination for Craniosynostosis. Pediatrics. 2016 Feb. 137 (2):e20152230. [Medline]. [Full Text].
Ploplys EA, Hopper RA, Muzaffar AR, Starr JR, Avellino AM, Cunningham ML, et al. Comparison of computed tomographic imaging measurements with clinical findings in children with unilateral lambdoid synostosis. Plast Reconstr Surg. 2009 Jan. 123(1):300-9. [Medline].
Fabijańska A, Węgliński T. The quantitative assessment of the pre- and postoperative craniosynostosis using the methods of image analysis. Comput Med Imaging Graph. 2015 May 23. [Medline].
Ernst CW, Hulstaert TL, Belsack D, Buls N, Van Gompel G, Nieboer KH, et al. Dedicated sub 0.1 mSv 3DCT using MBIR in children with suspected craniosynostosis: quality assessment. Eur Radiol. 2015 Jun 30. [Medline].
Danelson KA, Gordon ES, David LR, Stitzel JD. Using a three dimensional model of the pediatric skull for pre-operative planning in the treatment of craniosynostosis – biomed 2009. Biomed Sci Instrum. 2009. 45:358-63. [Medline].
Ernst CW, Hulstaert TL, Belsack D, Buls N, Van Gompel G, Nieboer KH, et al. Dedicated sub 0.1 mSv 3DCT using MBIR in children with suspected craniosynostosis: quality assessment. Eur Radiol. 2016 Mar. 26 (3):892-9. [Medline]. [Full Text].
Kaasalainen T, Palmu K, Lampinen A, Reijonen V, Leikola J, Kivisaari R, et al. Limiting CT radiation dose in children with craniosynostosis: phantom study using model-based iterative reconstruction. Pediatr Radiol. 2015 Sep. 45 (10):1544-53. [Medline].
Rijken BF, Leemans A, Lucas Y, van Montfort K, Mathijssen IM, Lequin MH. Diffusion Tensor Imaging and Fiber Tractography in Children with Craniosynostosis Syndromes. AJNR Am J Neuroradiol. 2015 Aug. 36 (8):1558-64. [Medline].
Linz C, Collmann H, Meyer-Marcotty P, Böhm H, Krauss J, Müller-Richter UD, et al. Occipital plagiocephaly: unilateral lambdoid synostosis versus positional plagiocephaly. Arch Dis Child. 2015 Feb. 100 (2):152-7. [Medline].
Majid A Khan, MD
Majid A Khan, MD is a member of the following medical societies: American College of Radiology, American Society of Neuroradiology
Disclosure: Nothing to disclose.
David I Weltman, MD Consulting Staff, S & D Medical, LLP; Director, Department of Radiology, Southside Hospital
David I Weltman, MD is a member of the following medical societies: American College of Radiology, American Roentgen Ray Society, New York County Medical Society, Association of Program Directors in Radiology, Radiological Society of North America
Disclosure: Nothing to disclose.
Bernard D Coombs, MB, ChB, PhD Consulting Staff, Department of Specialist Rehabilitation Services, Hutt Valley District Health Board, New Zealand
Disclosure: Nothing to disclose.
Marta Hernanz-Schulman, MD, FAAP, FACR Professor, Radiology and Radiological Sciences, Professor of Pediatrics, Department of Radiology, Vice-Chair in Pediatrics, Medical Director, Diagnostic Imaging, Vanderbilt Children’s Hospital
Marta Hernanz-Schulman, MD, FAAP, FACR is a member of the following medical societies: American Institute of Ultrasound in Medicine, American Roentgen Ray Society
Disclosure: Nothing to disclose.
Eugene C Lin, MD Attending Radiologist, Teaching Coordinator for Cardiac Imaging, Radiology Residency Program, Virginia Mason Medical Center; Clinical Assistant Professor of Radiology, University of Washington School of Medicine
Eugene C Lin, MD is a member of the following medical societies: American College of Nuclear Medicine, American College of Radiology, Radiological Society of North America, Society of Nuclear Medicine and Molecular Imaging
Disclosure: Nothing to disclose.
Charles M Glasier, MD Professor, Departments of Radiology and Pediatrics, University of Arkansas for Medical Sciences; Chief, Magnetic Resonance Imaging, Vice-Chief, Pediatric Radiology, Arkansas Children’s Hospital
Charles M Glasier, MD is a member of the following medical societies: American College of Radiology, American Society of Neuroradiology, Radiological Society of North America, Society for Pediatric Radiology
Disclosure: Nothing to disclose.
Dvorah Balsam, MD Chief, Division of Pediatric Radiology, Nassau University Medical Center; Professor, Department of Clinical Radiology, State University of New York at Stony Brook
Disclosure: Nothing to disclose.
Brian J Webber, DO Staff Physician, Department of Radiology, Nassau University Medical Center
Brian J Webber, DO is a member of the following medical societies: American Medical Student Association/Foundation and American Osteopathic Association
Disclosure: Nothing to disclose.
Craniosynostosis Imaging
Research & References of Craniosynostosis Imaging |A&C Accounting And Tax Services
Source
0 Comments