Microfocal CT: a method for evaluating murine cranial sutures in situ

INTRODUCTION: The murine model is a well-established surrogate for studying human cranial suture biology. In mice, all sutures with the exception of the posterior frontal (PF) suture remain patent throughout life. Histology is regarded as the gold standard for analyzing sutures. On this basis, PF suture fusion begins on day of life 25 and is complete by day 45. Cranial suture histology, however, requires sacrifice of the animal to obtain tissue for analysis. As a result, knowledge of the kinetics of cranial suture fusion is based on a patchwork analysis of many sutures from many different animals. The behavior of a single suture through time is unknown. Our goal is to develop a noninvasive means to repeatedly image mouse cranial sutures in vivo. As a first step, the present study was performed to evaluate microfocal computer tomography (micro-CT) technology for the use of capturing images of a mouse cranium in situ. METHODS: The micro-CT system consists of a microfocal X-ray source and a large format CCD camera optically coupled to a high-resolution X-ray image intensifier, digitally linked to a computer. The PF and sagittal sutures lie in continuity along the midline of the skull. Holes were drilled in the calvaria on both sides of the PF and sagittal sutures of a 45-day-old euthanized mouse. A micro-CT scan of this animal was performed and hundreds of cross-sectional images were generated for the cranium. These images were used to reconstruct three-dimensional volumetric images of the entire cranium. Comparisons were made between (1). the gross specimen and the three dimensional reconstructions; (2). two-dimensional coronal images obtained by micro-CT and those obtained by histology. RESULTS: Analysis of PF and sagittal sutures demonstrated the following: (1). The drilled holes were accurately rendered by micro-CT, when compared to both the gross specimen and the histology. (2). The sagittal suture was found to be patent by both micro-CT and histology. (3). The PF suture is fused by histology, but unexpectedly, the PF suture appears incompletely fused by micro-CT. By micro-CT, however, the anterior and endocranial regions appear more extensively fused than the remainder of the PF suture, a finding consistent with published histologic analysis. CONCLUSIONS: We successfully imaged 45-day-old mouse cranial sutures in situ using micro-CT technology. Precise correlation between histologic sections and radiologic images is difficult, but convincing similarities exist between the gross specimen and images from micro-CT and histology. PF suture fusion in a 45-day-old animal appears different by micro-CT than by histology. One possible explanation for this apparent discrepancy is that suture fusion in histology is determined based on the appearance of bone morphology and not tissue density, as the specimens are necessarily decalcified to section the bone. Micro-CT, on the other hand, distinguishes tissues on the basis of density. Newly forming bone may require bone matrix formation prior to complete calcification; PF suture in 45-day-old mice may be morphologically complete but incompletely ossified. Studies correlating histologic and micro-CT assessment of suture development are underway. Micro-CT appears to be a promising method for noninvasive imaging of mouse cranial suture.     

一种新的三维CT测量方法在评价颅缝早闭头颅不对称性畸形中的应用

目的 拟创用一种新的三维CT测量方法对先天性颅缝早闭头颅不对称性畸形患者进行诊断分析和手术疗效评价;同时,探讨该测量方法、指标与传统方法、指标相比的优缺点及临床意义.方法 在传统的颅顶不对称指数（cranial vault asymmetry index,CVAI）的基础上提出一种改良的CVAI：前颅顶不对称指数（anterior cranial vault asymmetry index,ACVAI）及后颅顶不对称指数（posterior cranial vault asymmetry index,PCVAI）,重建6例颅缝早闭患儿头颅的三维影像,测量头颅指数（cephalic index,CI）、CVAI、ACVAI及PCVAI,对各指标间进行统计学分析对比,分析头颅不对称畸形程度,评价术后头颅对称性的改善效果.结果 6例颅缝早闭患儿,术前、术后ACVAI的差值与CVAI差值相比差异有统计学意义（P＜0.05）;而CVAI术前、术后测量值差异无统计学意义（P＞0.05）.结论 ACVAI、PCVAI与CVAI相比能更加准确的反映出头颅的不对称性畸形,有助于对畸形程度进行分级,对手术疗效行定量化评价.     

Location of the traumatic subdural hygroma: role of gravity and cranial morphology

Traumatic subdural hygroma (TSH) is frequently bilateral and locates on the top of the head in a supine position. It suggests that the gravity and cranial posture act a certain role. The authors tried to test this hypothesis. The computed tomographic (CT) scans or magnetic resonance (MR) images of 86 consecutive patients with TSH were re-evaluated. The symmetry of the cranium, the posture of the head during the radiological examinations, and the location of the lesion were all checked. The cranium was symmetrical in 47 patients and asymmetrical in 39 patients. TSH was more commonly bilateral in patients with symmetrical cranium than those with asymmetrical cranium (77% vs 62%). The asymmetrical cranium tended to turn to the flat side. It was more frequently oblique in MR images, which has a long scanning time, than in CT (29% vs 18%). In 39 asymmetric craniums, TSH was bilateral and it was symmetrical in 14 cases. In the remaining 25 cases, TSH located opposite to the flat side in 18 cases. In seven patients with the same side TSHs,, four patients had it on the side of atrophy, two on the opposite side of a mass lesion. The gravity and cranial posture can predict the location of TSH. TSH usually occurs at the least pressure in the cranium as a lesion of ex vacuo .     

Posterior Cranial Vault Distraction Osteogenesis with Barrel Stave Osteotomy in the Treatment of Craniosynostosis

Twenty years have passed since distraction osteogenesis was introduced into the field of craniomaxillofacial surgery, with distraction osteogenesis gradually consolidating its position for midface advancement in syndromic craniosynostosis. On the other hand, no consensus has been reached regarding its adaptation to calvarial bone. We reported that distraction osteogenesis was useful in posterior cranial vault expansion, and subsequently, similar reports have been successively observed worldwide. In posterior cranial vault distraction, intracranial capacity could be greatly expanded due to its simultaneous expansion with the scalp, with little risk of relapse because new bone is regenerated in the distraction gap. The possibility was suggested that the standard of first carrying out fronto-orbital advancement (FOA) for brachycephaly observed in syndromic craniosynostosis will greatly change posterior cranial vault distraction.     

Evaluating Cranial Growth in Japanese Infants Using a Three-dimensional Scanner: Relationship between Growth-related Parameters and Deformational Plagiocephaly

In this study, we aimed to evaluate the longitudinal changes in the cranial shape of healthy Japanese infants using a three-dimensional scanner and construct a normal values database for the growth process. Preterm infants (gestational age < 37 weeks), infants with neonatal asphyxia (5-minute Apgar score of <7), and patients who started helmet therapy for deformational plagiocephaly were excluded from this study. The first scan was performed at approximately 1 month of age, followed by two scans conducted at 3 and 6 months of age. The parameters considered were as follows: cranial length, width, height, circumference, volume, cranial vault asymmetry index, and cephalic index. A cranial vault asymmetry index >5% was defined as deformational plagiocephaly. Changes in each parameter were examined using repeated-measures analysis of variance classified by sex and deformational plagiocephaly status. The rate of increase in each parameter was also examined. In total, 88 infants (45 boys and 43 girls) were included in this study. All growth-related parameters were noted to increase linearly with time. Sex differences were observed in all parameters except cranial length. Deformational plagiocephaly was found to have no effect on growth-related parameters. Cranial volume increased by 60% from 1 to 6 months of age. The growth almost uniformly influenced the rate of increase in volume in each coordinate axis direction. Overall, the mean trends in three-dimensional parameters in infants up to 6 months of age were obtained using a three-dimensional scanner. These trends could be used as a guide by medical professionals involved in cranioplasty.     

The growth patterns of normal skull by using CT scans and their clinical applications for preoperative planning and postoperative follow-up in craniofacial surgery

Summary In the operative treatment of craniosynostosis, the accurate criteria for the extent of fronto-orbital advancement and/or reshaping have not been published. In this study, the growth and configuration of the forehead, anterior cranial base and occipital region have been investigated using CT scans. In addition to its intrinsic worth, the information obtained is also useful for preoperative planning of advancement and/or reshaping in craniosynostosis surgery, and also for post-operative follow-up.Presented at the 2nd International Congress of Craniomaxillofacial Surgery, Florence, Italy, June 1989     

生长因子在颅缝早闭症中作用的研究进展

颅缝早闭是一种较常见的先天性颅面畸形,表现为一条或多条颅缝过早闭合。多种因素可以在胚胎期及出生后影响头骨的发育,从而导致不同类型的颅缝早闭。目前研究表明,生长因子与颅缝闭合过程有着密切的联系,本文就生长因子在颅缝早闭症中作用的研究进展进行综述。     

Interrelationship of Cranial Suture Fusion, Basicranial Development, and Resynostosis Following Suturectomy in Twist1+/? Mice, a Murine Model of Saethre-Chotzen Syndrome

The interrelationships among suture fusion, basicranial development, and subsequent resynostosis in syndromic craniosynostosis have yet to be examined. The objectives of this study were to determine the potential relationship between suture fusion and cranial base development in a model of syndromic craniosynostosis and to assess the effects of the syndrome on resynostosis following suturectomy. To do this, posterior frontal and coronal suture fusion, postnatal development of sphenooccipital synchondrosis, and resynostosis in Twist1(+/+) (WT) and Twist1(+/-) litter-matched mice (a model for Saethre-Chotzen syndrome) were quantified by evaluating μCT images with advanced image-processing algorithms. The coronal suture in Twist(+/-) mice developed, fused, and mineralized at a faster rate than that in normal littermates at postnatal days 6-30. Moreover, premature fusion of the coronal suture in Twist1(+/-) mice preceded alterations in cranial base development. Analysis of synchondrosis showed faster mineralization in Twist(+/-) mice at postnatal days 25-30. In a rapid resynostosis model, there was an inability to fuse both the midline posterior frontal suture and craniotomy defects in 21-day-old Twist(+/-) mice, despite having accelerated mineralization in the posterior frontal suture and defects. This study showed that dissimilarities between Twist1(+/+) and Twist1(+/-) mice are not limited to a fused coronal suture but include differences in fusion of other sutures, the regenerative capacity of the cranial vault, and the development of the cranial base.     

Infantile craniosynostosis: Clinical,radiological, and surgical considerations based on 100 surgically treated cases

Summary One hundred children affected by craniosynostosis were operated on from January 1952 to February 1977.Forty-six patients were operated on within the first year of life, and only 9 after six years of age.In 27 cases only one cranial suture was synostotic (mostly the coronal: 15 cases). In 36 cases two sutures were involved (mostly coronal plus sagittal: 25 cases). In 28 cases all the cranial sutures were involved. Also included in this series are seven cases of Crouzon's, one of Apert's, and one of Carpenter's syndromes. The clinical, radiological, and surgical features of this condition are discussed, and the long-term results are reported.     

Computed Tomographic Evaluation Before Cranial Bone Harvesting to Avoid Unexpected Hazards During Aesthetic Procedures

Nowadays, cranium is the preferred bone-graft donor site for facial aesthetic operations. Preoperative information about the quality of cranial bone, such as bone thickness or presence of the diplopic space, can be useful to minimize intracranial complications. This fact is neglected in reconstructive and aesthetic surgery. The aim of this study is to assess the reliability of Computed Tomography (CT) to determine cranial bone quality. Sixty-four cadaver parietal bones, the preferred site for bone-graft harvesting, were used in this study. In the first stage, posterior parietal bone thickness, which is accepted as the thickest part of cranium, was measured at specially determined points using a micrometer and the results were recorded. Bone thickness was then measured again in the same points with CT. The two methods were compared statistically. The measurements were not found to be statistically different. The similar values obtained with CT and micrometers suggest that CT can accurately and reliably determine cranial thickness. Preoperative CT can be a significant guide for the harvest of cranial bone grafts without any intracranial complications in aesthetic surgery.     

Morphological character of cervical spine for anterior transpedicular screw fixation

Background:

Anterior cervical interbody grafts/cages combined with a plate were frequently used in multilevel discectomies/corpectomies. In order to avoid additional posterior stabilization in patients who undergo anterior reconstructive surgery, an anterior cervical transpedicular screw fixation, which offers higher stability is desirable. We investigated in this study the anatomical (morphologic) characters for cervical anterior transpedicular screw fixation.

Materials and Methods:

Left pedicle parameters were measured on computed tomography (CT) images based on 36 cervical spine CT scans from healthy subjects. The parameters included outer pedicle width (Distance from lateral to medial pedicle surface in the coronal plane), outer pedicle height (OPH) (Distance from upper to lower pedicle surface in the sagittal plane), maximal pedicle axis length (MPAL), distance transverse insertion point (DIP), distance of the insertion point to the upper end plate (DIUP), pedicle sagittal transverse angle (PSTA) and pedicle transverse angle (PTA) at C3 to C7.

Results:

The values of outer pedicle width and MPAL in males were larger than in females from C3 to C7. The OPH in males was larger than in females at C3 to C6, but there was no difference at C7. The DIP and PTA were significantly greater in males than in females at C3, but there was no difference in the angle at C4-7. The PSTA was not statistically different between genders at C3, 4, 7, but this value in males was larger than females at C5, 6. The DIUP was significantly greater in males at C3, 4, 6, 7 but was non significant at C5.

Conclusions:

The placement of cervical anterior transpedicular screws should be individualized for each patient and based on a detailed preoperative planning.     

外伤性颅后窝血肿84例分析

目的 总结８４例外伤性颅后窝血肿病人的临床特点，诊治经验。方法 对８４例外伤笥颅后窝血肿病人进行回顾性总结。结果 手术治疗５８例，治愈４３例，好转８例，死亡７例，非手术治疗２４例，治愈１９例，好转２例，死亡３例。２例在行术前准备时死亡。结论颅后窝血肿早期缺乏特异症状及体征，ＣＴ扫描易忽略而漏诊，对枕部头皮损伤，特别有枕骨骨得应警惕颅后窝血肿，颅后窝应作ＣＴ薄层扫描，及时手术预后等。     

Intracranial volume change in craniosynostosis.

OBJECT: There is still controversy regarding the optimum time to perform surgery for craniosynostosis. Some recommend surgery soon after birth and others delay until the age of 12 months. Intracranial pressure has been measured in an attempt to provide a scientific rationale, but many questions remain unanswered. To date, little attention has been given to intracranial volume and its changes during the first few years of life in children with craniosynostosis. The authors' goal was to focus on intracranial volume during this period and to compare measurements obtained in patients with craniosynostosis with measurements obtained in healthy individuals. METHODS: Using the technique of segmentation, the intracranial volume of 84 children with various forms of craniosynostosis was measured on preoperative computerized tomography scans. The change in average volume that occurs with increasing age was calculated and compared with a model of normal intracranial volume growth. The age at presentation for children with craniosynostosis was 1 to 39 months; 76% of the patients were younger than 12 months. In eight patients in whom only one cranial expansion procedure was performed, postoperative intracranial volumes were measured as well. Several interesting observations emerged. 1) There was little difference in head growth between boys and girls with craniosynostosis during the first few months of life. After the age of 12 months, however, the difference in intracranial volume normally seen between the two genders was observed in the craniosynostosis group as well. 2) Excluding children with complex pansynostosis, who have smaller heads, children with all other types of craniosynostosis have similar head growth after the 1st year of life, with no difference between the number of and type of suture affected. Children with Apert's syndrome develop greater than normal intracranial volumes after the 1st year of life. 3) Although children with craniosynostosis are born with a smaller intracranial volume, by the age of 6 months volume has reached normal levels, and from that point on volume follows the pattern of normal head growth. 4) Children who presented after the age of 6 months and later developed recurrent craniosynostosis after initial successful treatment had a small intracranial volume at their initial presentation. 5) Of the patients whose postoperative intracranial volumes were measured, all but one had preoperative volumes at or above normal values, and their postoperative volumes were considerably higher than normal for their age. These children all followed a growth curve parallel to that of healthy children but at higher volume value. One patient with a smaller-than-normal initial intracranial volume was surgically treated at a very young age and, despite cranial expansion surgery, postoperative volume did not reach normal levels. It is postulated that this was due to the fact that the operation was performed at a time when craniosynostosis was still active. CONCLUSIONS: The results of this study indicate that the underlying mechanism leading to craniosynostosis and constriction of head volume "exhausts" its effect during the first few months of life. Measurement of intracranial volume in clinical practice could be used to "fine tune" the optimum time for surgery. In late-presenting children, this may be useful in predicting possible recurrence.     

Surgical advancement influences perioperative care: a comparison of two surgical techniques for sagittal craniosynostosis repair

Methods for surgical correction of sagittal craniosynostosis have progressed. The hypothesis is that advances in surgical interventions for craniosynostosis affect perioperative anesthetic care. We reviewed the records of eight children who underwent cranial vault reconstruction (CVR) and nine who underwent spring-mediated cranial expansion (SME) for sagittal craniosynostosis. We compared the data from the CVR procedure to data from the combined procedures for SME (insertion and removal of springs). Anesthesia times were similar between the CVR (4 h 24 min) and the combined SME (4 h 27 min) groups, whereas surgical times were different between the CVR (3 h 25 min) and combined SME groups (2 h 21 min) (P = 0.002). Length of stay was 4.1 days for the CVR group (confidence interval [CI], 3.8-4.4 days) versus 3.1 days (CI, 2.9-3.4 days) in the combined SME group (P = 0.0001). Blood loss was significantly less in the combined SME group at 48 mL (CI, 29-83 mL) compared with the CVR group at 291 mL (CI, 230-352 mL). All eight patients in the CVR group received blood with a mean of 1.4 U (range, 1-2 U). No SME patient received any blood products. The reduction in blood loss with this new surgical treatment is significant for the patient in reducing blood transfusion and for the anesthesiologist in reducing concerns of volume resuscitation.     

低张水充盈薄层螺旋CT增强扫描对胃癌的诊断价值

目的:探讨低张水充盈薄层螺旋CT增强扫描对胃癌的诊断价值。方法:对32例胃癌患者进行低张气钡双对比造影及低张水充盈薄层螺旋CT增强扫描,并与术后病理相对照。结果:胃癌的CT表现主要有:胃壁增厚、显著增强的软组织肿块、胃内不规则充盈缺损、胃腔狭窄、淋巴结及远处脏器转移、邻近脏器侵犯。肿瘤门脉期增强较动脉期显著。低张水充盈薄层螺为CT增强扫描对胃癌的检出率为100％,对胃癌TNM分期准确率为82％。结论:低张水充盈薄层螺旋CT增强扫描对胃癌的诊断和分期有重要价值,准确性明显高于其他检查方法。     

New diagnostic imaging for navigation surgery

Progress in diagnostic computed tomography (CT) and magnetic resonance (MR) imaging has been remarkable. Multidetector-row CT provides thin-slice images through the upper abdomen, multiphase abdominal imaging, and 3D images of high quality including CT angiography and multiplanar reformation. The development of MR units provides diffusion-weighted images for detecting abdominal tumors, and the steady-state coherent echo method can be used for imaging of vessels without using contrast media. The 3D images provided in CT and MR imaging facilitate anatomic understanding of tumors and vessels and are useful for preoperative navigation. However, we must be careful when using 3D images for diagnosis, because the subjectivity of the 3D image creator may affect the results. Therefore the original axial images should also be referred to.     

An autosomal dominant high bone mass phenotype in association with craniosynostosis in an extended family is caused by an LRP5 missense mutation.

Gain-of-function mutations in LRP5 have been shown to cause high BMD disorders showing variable expression of some clinical symptoms, including torus palatinus and neurological complications. In an extended family, we were able to add craniosynostosis and developmental delay to the clinical spectrum associated with LRP5 mutations. We report on an extended four-generation family with 13 affected individuals (7 men and 6 women) in which an autosomal dominant type of osteosclerosis segregates. Osteosclerosis was most pronounced in the cranial base and calvarium, starting in early childhood with variable expression and a progressive character. Craniosynostosis at an early age was reported in four affected family members (two males and two females). The patients also presented with dysmorphic features (macrocephaly, brachycephaly, wide and high forehead, hypertelorism, prominent cheekbones, prominent jaw). They have normal height and proportions. Neurological complications like entrapment of cranial nerves resulting in optical nerve atrophy, hearing loss, and facial palsy were reported in two individuals. A mild developmental delay was reported in three affected individuals. None of the patients have torus palatinus, increased rate of fractures, osteomyelitis, hepatosplenomegaly, or pancytopenia. A missense mutation 640G-->A (A214T) in the low-density lipoprotein receptor-related protein 5 (LRP5) gene was found in all affected individuals analyzed, including cases in whom craniosynostosis, a mild developmental delay, and/or macrocephaly is observed. To our knowledge, this is the first report in the literature of patients presenting with autosomal dominant osteosclerosis in whom a variable expression of craniosynostosis, macrocephaly, and mild developmental delay is observed, which is most likely associated with a mutation in the LRP5 gene. These phenotypes can therefore be added to the clinical spectrum of LRP5-associated bone disorders.     

生长因子FGF在颅缝细胞培养中作用的研究

目的:研究生长因子FGF在颅缝闭合中的调控作用.方法:以颅缝早闭动物模型(SD鼠)的颅缝为研究模型,采用细胞生物学技术、组织化学技术,研究颅缝闭合期间,生长因子bFGF作用下,细胞胶原及骨钙素分泌情况;观察生长因子bFGF,对分离培养的颅缝细胞增殖与代谢影响.结果:在大鼠颅缝分离培养细胞中,bFGF促进颅缝分离培养细胞分泌胶原、骨钙素,加快细胞增殖生长曲线平台期出现,并有效促进大鼠颅缝分离培养细胞S期增殖(p＜0.05).结论:在体外器官培养中,bFGF能促进大鼠分离培养颅缝细胞的活性(p＜0.05).     

螺旋CT多层面和多维重建在泌尿系疾病诊断中的应用

目的探讨螺旋CT尿路多层面重建（MPR）加多维重建（3D和4D）技术在泌尿系疾病诊断中的应用价值。方法采用螺旋CT薄层扫描多层面重建和多维重建技术对106例泌尿系疾病患者进行检查。106例患者中，男70例，女36例。年龄16～82岁，平均51岁。泌尿系结石92例（87％），其中左输尿管上段软结石1例，马蹄肾合并输尿管结石1例、肾癌1例、肾盂癌3例、输尿管癌1例、膀胱癌4例、肾损伤3例、肾动脉栓塞肾部分梗死1例。对肿瘤患者常规进行CT血管造影。结果106例患者均获明确诊断，泌尿系结石CT多维重建或MPR检查可显示高密度结石致密影及结石铸型、梭形或不规则形态，与手术切开取石或体外碎石排石结果一致。9例肿瘤CT多维重建或MPR检查显示不规则软组织块影，并能显示管壁增厚、狭窄或团块样改变，膀胱肿瘤尚能立体显示腔内侵袭深度及与周围组织关系，与术中所见和术后病理结果相符。结论螺旋CTMPR及多维成像分辨率高、检查时间短、侵袭性小，可增加图像立体感和透明度，使病变显示更为清晰，可作为泌尿系疾病最有价值的诊断方法之一。     

Does the shunt opening pressure influence the effect of shunt surgery in normal pressure hydrocephalus?

Summary Thirteen patients with normal pressure hydrocephalus were operated upon with an externally manoeuvrable shunt system (Sophy SU8) in order to investigate its influence on clinical outcome, intracranial pressure and cranial CT parameters. The opening pressure was set at high at surgery and lowered stepwise at intervals of three months to medium and low. The clinical condition, intracranial pressure and cranial CT parameters were examined at the end of the 3 months interval on each pressure level.The patients improved within the first 3 months inspite of an unchanged mean intracranial pressure and remained in a stable clinical condition during the rest of the study period. The intracranial pressure was significantly reduced at 9 months. The ventricular index, Evans index, temporal horn and third ventricle width were reduced 3 months post-operatively and did not change significantly during the rest of the study. The pre-operative third ventricle width was correlated to high psychometric test results after shunt surgery. Reduction in ventricular index, Evans index and third ventricle width after surgery correlated to improvement in psychometric scoring.The clinical improvement after shunt surgery for normal pressure hydrocephalus is seen within 3 months and is independent of the adjusted valve pressure.