The role of magnetic resonance imaging in the preoperative assessment of anorectal anomalies

The role of magnetic resonance imaging (MRI) compared to other investigations in providing information relevant to and affecting surgical management in patients with anorectal anomalies (ARA) was studied in two groups of patients. In group 1 a pilot study was done in 9 patients with colostomy for high ARA awaiting posterior sagittal anorectoplasty. These patients had MRI, plain radiographs, a distal loopogram through the mucous fistula, ultrasound scans of the spinal cord and urinary tract, and a micturating cystourethrogram. The level of bowel and spinal-cord termination was correctly determined in all patients by MRI and conventional investigations. The presence or absence of a fistula, urological abnormalities, and bony abnormalities of the pelvis and spine were better visualized by conventional investigations than with MRI. The striated-muscle complex (SMC) was well-visualized by MRI, the thickness accurately graded, and the findings confirmed at operation. The information on muscle thickness and the presence or absence of a fistula was interesting, but played no part in decisions made about surgical management, and the operative technique was not altered. In group 2 the patients were much older and had MRI for persistent problems, mainly soiling; 6 had low lesions and 6 had high lesions. Three patients with low lesions were found to have intraspinal abnormalities on MRI; 4 were found to have malpositioned bowel in the SMC, which was again accurately visualized and graded. Therefore, in 7/12 patients of this group a surgically correctable abnormality was found. We conclude that MRI has no role as a primary investigation in patients with high ARA, but it is useful if there are suspected spinal-cord problems or persistent problems after definitive surgery. Accepted:  6 May 1998     

Abnormal anatomy of the lumbosacral region imaged by magnetic resonance in children with anorectal malformations

OBJECTIVE: To investigate the frequency of lumbosacral anomalies, the association with urogenital abnormalities, and the correlation with defaecation pattern by magnetic resonance imaging (MRI). METHODS: A prospective analysis was performed of routine MRI in patients with anorectal malformations. Between 1990 and 1994, MRI was performed in 43 such patients: 31 boys and 12 girls. Twenty four had a high anorectal malformation, 16 had a low anorectal malformation, and three had Currarino's triad. MRI was performed before reconstruction in 26, and postoperatively in 17. Urogenital anomalies were found in 21. RESULTS: Abnormalities of the spinal cord and spine were found with MRI in 20 patients (46.5%); caudal regression syndrome in 10, tethered cord in two, a combination of both in three, and other spinal anomalies in five. These anomalies were found in 30% of the patients with low anorectal malformations, and in 50% with high anorectal malformations. In patients with urogenital malformations, MRI more often showed spinal anomalies (13/21, 62%) than in patients without (7/22, 32%). In high anorectal malformations, defaecation was more often a problem in patients with spinal anomalies (12/15, 80%) than in patients without (2/8, 25%). CONCLUSIONS: Spinal anomalies in the lumbosacral region were found with MRI in 46.5% of patients with anorectal malformations. Since presence of these anomalies seems to be related to clinical outcome, MRI should be performed routinely in all such patients.     

Abnormal anatomy of the lumbosacral region imaged by magnetic resonance in children with anorectal malformations.

OBJECTIVE: To investigate the frequency of lumbosacral anomalies, the association with urogenital abnormalities, and the correlation with defaecation pattern by magnetic resonance imaging (MRI). METHODS: A prospective analysis was performed of routine MRI in patients with anorectal malformations. Between 1990 and 1994, MRI was performed in 43 such patients: 31 boys and 12 girls. Twenty four had a high anorectal malformation, 16 had a low anorectal malformation, and three had Currarino''s triad. MRI was performed before reconstruction in 26, and postoperatively in 17. Urogenital anomalies were found in 21. RESULTS: Abnormalities of the spinal cord and spine were found with MRI in 20 patients (46.5%); caudal regression syndrome in 10, tethered cord in two, a combination of both in three, and other spinal anomalies in five. These anomalies were found in 30% of the patients with low anorectal malformations, and in 50% with high anorectal malformations. In patients with urogenital malformations, MRI more often showed spinal anomalies (13/21, 62%) than in patients without (7/22, 32%). In high anorectal malformations, defaecation was more often a problem in patients with spinal anomalies (12/15, 80%) than in patients without (2/8, 25%). CONCLUSIONS: Spinal anomalies in the lumbosacral region were found with MRI in 46.5% of patients with anorectal malformations. Since presence of these anomalies seems to be related to clinical outcome, MRI should be performed routinely in all such patients.     

Pre-operative MRI of anorectal anomalies in the newborn period

Nine infants (six boys, three girls) with anorectal anomalies were examined in the immediate newborn period, prior to corrective surgery, with MRI. Three high, one intermediate and five low anomalies were found at MRI - one patient with a “low” lesion was subsequently found at surgery 2 months later to have a high anorectal anomaly. This infant had passed meconium per urethram soon after the MRI study, prompting the need for a protective colostomy and stressing the importance of a thorough clinical examination of babies with anorectal malformations. The MRI results and findings at surgery were in agreement in all other patients (n = 8). Hydronephrosis was evident in two and renal agenesis in one patient. Sacrococcygeal hypoplasia was found in two and two hemivertebrae in one infant. No spinal cord lesion was identified. One fistula was evident on MRI but four were later found at surgery. Uniformly hyperintense T1 signal meconium was seen in all nine newborns, allowing for easy differentiation of rectal contents from rectal wall and the adjacent musculature. MRI can provide useful information regarding the development of the puborectal and external anal sphincter muscles, can help guide the pull-through procedure and help predict future continence pre-operatively in the newborn period.

     

Spinal dysraphism: use of magnetic resonance imaging in evaluation

Three cases of children with spinal dysraphism are reported. Magnetic resonance imaging (MRI) was used as a primary diagnostic examination. The ages of the patients were 2 days, 4 years, and 16 years. In all instances the scan gave a precise diagnosis as well as well as an accurate delineation of the structural abnormalities before surgical treatment. Plain radiographs and ultrasound analysis may not be helpful, and invasive procedures can be associated with morbidity. Technical ease, safety, and anatomic precision suggest that MRI should be performed as a primary radiologic examination in the diagnostic workup of spinal dysraphism.     

Spinal cord compression caused by extradural arachnoid cysts. Clinical examples and review

Most spinal arachnoid cysts are asymptomatic and detected incidentally during magnetic resonance imaging or myelography. The etiology of intraspinal arachnoid cyst is not yet clear. We present two children with three spinal extradural arachnoid cysts and each cyst protruded from a separate dura defect. In both patients, plain radiographs demonstrated widening of the interpedicular distance, which suggested progressive widening of the spinal bony canal. Limited laminectomy was performed to remove the intraspinal cysts. Separate dura defects, the apparent predisposing factors, were also found and repaired. The patients completely recovered neurologically. Radical cyst removal and dura defect closure are the surgical intervention of choice in patients with symptomatic extradural arachnoid cyst.     

Magnetic resonance imaging of spinal cord disease of childhood

Correct diagnosis of spinal cord disease in childhood is often delayed, resulting in irreversible neurologic deficits. A major reason for this delay is the lack of a reliable means to noninvasively visualize the spinal cord. Magnetic resonance imaging (MRI) should be useful in the evaluation of diseases of the spinal cord. A 1.5 Tesla MRI unit with a surface coil was used to study 41 children, including eight patients with intrinsic spinal cord lesions, eight patients with masses compressing the cord, 12 patients with congenital anomalies of the cord or surrounding bony structures, three patients with syrinxes, and three patients with vertebral body abnormalities. Intrinsic lesions of the cord were well seen in all cases as intrinsic irregularly widened, abnormally intense cord regions. MRI was helpful in following the course of disease in patients with primary spinal cord tumors. Areas of tumor were separable from syrinx cavities. Extrinsic lesions compressing the cord and vertebral body disease were also well visualized. Congenital anomalies of the spinal cord, including tethering and lipomatous tissue, were better seen on MRI than by any other radiographic technique. MRI is an excellent noninvasive "screening" technique for children with suspected spinal cord disease and may be the only study needed in many patients with congenital spinal cord anomalies. It is also an excellent means to diagnose and follow patients with other forms of intra- and extraspinal pathology.     

Cervical spinal cord injury in abused children

Five infants and toddlers who sustained cervical spinal cord injury as the result of child abuse are described. Three cases are previously unreported. Diagnosis was complicated by coexistent brain injuries and their treatments, subtle and/or evolving paralysis, and central cord syndrome, in which arm function is diminished but leg function is preserved. Definitive spinal imaging by magnetic resonance imaging (MRI), computed tomography, and plain radiographs was delayed because of life support efforts. When completed, the MRI was most sensitive to cord injury. Evidence of associated bony spinal injury was often absent or unapparent until healing occurred; 4 children had spinal cord injury without (or with minimal) radiological abnormality. The 3 children presenting to our hospital with cord injury represent 1% of the estimated cases of inflicted head injury seen during a 23-year period.     

High resolution ultrasound with Doppler: A diagnostic adjunct in orbital and ocular lesions in children

Twenty-six infants and children with orbital and ocular pathology were examined with ultrasound (US) utilizing real-time imaging and Duplex Pulsed Doppler evaluation. Twenty-two of these patients underwent concurrent orbital computed tomography (CT) and two had magnetic resonance imaging (MRI). Orbital and periorbital lesions included hemangioma, dermoid, lymphangioma, rhabdomyosarcoma, encephalocoele and abscess. Ocular lesions included infection, trauma, retinal detachment, retinoblastoma, Coat's disease, and persistent hyperplastic primary vitreous. High resolution US with Doppler provided unique diagnostic information in patients with penetrating ocular trauma, orbital and periorbital masses, and intraocular structural abnormalities. High resolution US examination of the eye and periorbital tissues is readily performed using widely available equipment and often delineates subtle structural abnormalities not shown by CT or MRI.     

Anorectal malformations with sacral bony abnormalities.

A range of anorectal malformations with sacral bony abnormalities was found in members from three generations of two kindreds. The anorectal anomaly was low in all but one of the patients. Partial sacral agenesis was the main bony defect in one family, and meningomyelocele and spina bifida occulta were noted in the second. The inheritance pattern in these kinships is autosomal dominant. This may be a variant of caudal regression syndrome, which seems to be aetiologically heterogeneous.     

The utility of the plain radiograph “shunt series” in the evaluation of suspected ventriculoperitoneal shunt failure in pediatric patients

Background To our knowledge, the sensitivity of plain radiography, known as the shunt series, in diagnosing an etiology of ventriculoperitoneal (VP) shunt malfunction in children has not been previously investigated. Objective To determine the accuracy of plain radiography in diagnosing VP shunt failure in children in whom shunt malfunction is clinically suspected. Materials and methods We retrospectively reviewed the charts of 238 children who had undergone plain radiographic examination for evaluation of clinically suspected VP shunt failure over a 5-year period. The results were compared with those of CT, MRI, and nuclear cisternography. Results Just 6.72% of patients demonstrated plain radiographic signs of shunt failure. Of patients with normal plain radiographs, 43% demonstrated shunt abnormalities on CT, MRI or cisternography. Statistical analysis indicated that no more than 10.46% (P < 0.05) of plain radiographs showed signs of failure and that the sensitivity of plain radiography for the detection of VP shunt failure is no higher than 31%. Furthermore, there was poor agreement between the results of plain radiography and those of CT, MRI and cisternography. Conclusion Children with clinically suspected VP shunt failure should proceed directly to cross-sectional or nuclear imaging, as plain radiographic examinations have low sensitivity and significant false-negative rates for detecting shunt abnormalities in all-comers. Use of the shunt series should be limited to patients who specifically have suspected mechanical causes of shunt failure.     

Brachytelephalangic chondrodysplasia punctata with severe spinal cord compression: report of four new cases

Brachytelephalangic chondrodysplasia punctata (CDPX1, OMIM: #302950) is a rare congenital skeletal dysplasia caused by arylsulfatase E deficiency (OMIM: #300180). Although the symptoms are usually mild, severe spinal cord compression by dysplastic vertebras may develop. We report four new cases with severe cervical spinal canal narrowing documented by radiography, magnetic resonance imaging (MRI), and autopsy. In all, nine cases of CDPX1 with severe cervical spinal cord compression have now been described. Because these cases account for a large proportion of all reported CDPX1 cases, we believe that an antenatal suspicion of CDPX1 should lead to genetic counseling and to investigations for spinal cord compression. After birth, this complication must be routinely anticipated, and we suggest spinal MRI in all CDPX1 infants. Unless spinal cord compression is confidently ruled out, we recommend that these newborns receive the same care as trauma patients suspected of craniocervical junction disruption. No conflicts of interest occurred for this work.     

Spinal cord injury without radiographic abnormalities

Spinal cord injury without radiographic abnormality (SCIWORA) has a reported rate of incidence varying from 19% to 34% of all spinal cord injuries in children. This acronym refers to the presence of neurological lesion, despite normal plain radiographs, but where magnetic resonance imaging (MRI) shows significant pathology. The clinical evidence of the damage could be delayed in 6–54% of cases, usually within 48 h after the trauma. We report two patients affected by SCIWORA in the pediatric population. The first patient was a child of 22 months who had fallen when attempting to get out of bed. The second patient was an 11-month-old child admitted to the Emergency Service department after a car accident. Spinal cord injury has to be suspected in the presence of neurological signs, despite normal plain radiography. MRI is the appropriate diagnostic examination to identify the presence of SCIWORA.     

Electromyographic studies on the external anal sphincter in children with operated anorectal malformations.

Fecal incontinence is a common problem after surgical repair in patients with anorectal malformations. A normally functioning external anal sphincter (EAS) mechanism is a major factor for continence. The aim of this study was to assess the function of the EAS in children with operated anorectal malformations by electromyography (EMG) and to refine the sphincter function further. The study group consisted of 8 patients with incontinence problems who were operated for anorectal malformations. The electrical activity of EAS was evaluated by EMG using concentric needle electrodes in all subjects. The presence, localization, integrity and activity of the sphincter were assessed. Seven of 8 patients showed electrical activity of the EAS. Sphincter localization was found to be appropriate in six children. Five children showed a well preserved sphincter integrity and 2 of them disclosed normal EMG activity. In cases of localization or integrity abnormalities, secondary corrective surgery was planned, while in patients showing only abnormal EMG activity, biofeedback treatment was given. In cases of fecal incontinence in patients with operated anorectal malformations, electromyographic study shows the type of sphincter abnormality and further helps to make a decision whether to improve the EAS function with conservative treatment or surgically.     

Soft tissue signal abnormality associated with eosinophilic granuloma

Six patients with eosinophilic granuloma were studied retrospectively in order to correlate the MRI appearances with the pathology. Ages ranged from 2 years 6 months to 11 years. The bones involved were the humerus, ulna, radius, femur, clavicle and ilium. Plain films, MRI and pathology specimens were obtained. A lytic lesion with indistinct margins, endosteal erosions and periosteal reaction was seen in all cases on plain radiographs. Bone marrow signal was decreased on T1-weighted images and increased on T2-weighted images throughout the bony lesion in all cases. T2-weighted images showed extensive soft-tissue abnormalities suggesting inflammatory changes in four cases. In two cases abnormalities were limited. Extensive changes correlated histologically with an early phase lesion. Localized minor changes were associated with a mid-phase lesion. Inflammatory soft-tissue changes could be associated with eosinophilic granuloma. The size of the soft tissue mass correlated well with the activity of the bony lesion.     

Radiology of anorectal malformations: What does the surgeon need to know?

Imaging is extremely important throughout all phases of care provided to children with anorectal malformations (ARM). A preoperative determination of the patient specific malformation will help establish the operative plan. Moreover, the majority of ARM patients will have an associated anomaly that will require imaging workup for full understanding of those abnormalities prior to addressing the ARM. The complexity of ARM care will mandate continued imaging throughout the post-operative period even in those with straight forward malformations.     

The paediatric wrist revisited—findings of bony depressions in healthy children on radiographs compared to MRI

Background

The presence of erosions is used for diagnosis and monitoring of disease activity in juvenile idiopathic arthritis (JIA). Assessment of carpal bone erosions in children is challenging due to lack of normal references.

Objective

To define normal appearances of bony depressions in the wrist on radiographs and MRI.

Materials and methods

MRI and radiography of the wrist were performed in 88 healthy children, 5–15?years of age. We assessed the number of bony depressions within the carpals/proximal metacarpals on both modalities, separately and combined.

Results

A total of 75 carpal depressions were identified on radiography compared to 715 on MRI. The number of bony depressions identified radiographically showed no statistically significant difference across age-groups. Within the metacarpals, there was no significant difference between bony depressions identified by MRI or radiography, except at the bases of the second metacarpal.

Conclusion

Bony depressions that resemble erosions are normal findings in the wrist in children. MRI identifies more depressions than radiographs in the carpus. Some bony depressions occur at typical locations and should be accounted for when assessing the wrist in JIA to avoid overstaging.     

Nonfluoroscopic pressure colostography in the evaluation of genitourinary fistula of anorectal malformations: experience in a resource-poor environment

Background  Radiological imaging is paramount for defining the genitourinary fistulae commonly associated with anorectal malformations prior to definitive surgery. The imaging options are resource-limited in many parts of the world. Nonfluoroscopic pressure colostography after colostomy is a cheap method for the evaluation of anorectal malformations. Objective  To describe our experience with nonfluoroscopic pressure colostography in the evaluation of anorectal malformations in boys. Materials and methods  The study included 12 boys with anorectal malformation who had colostomy and nonfluoroscopic pressure-augmented colostography with water-soluble contrast medium between January 2006 and December 2007. Results  Patient ages ranged from 2 days to 1 year. The types of genitourinary fistula were rectovesical (7.7%) and rectourethral (92.3%). Oblique radiographs were of diagnostic value in all patients. The types of anorectal malformations were high, intermediate and low in 75%, 8.3% and 16.7%, respectively. Short-segment urethral constriction was a common feature of rectourethral fistula (75%, n=9). Conclusion  Our experience has shown that genitourinary fistulae associated with anorectal malformations can be demonstrated reliably by nonfluoroscopic pressure colostography with two oblique radiographs, providing an option in resource-poor settings where fluoroscopic equipment is scarce.     

Isolated bifid rib: Clinical and radiological findings in children

Background: Bifid rib is usually asymptomatic but sometimes occurs associated with other pathological conditions. The aim of this study was to investigate clinical and radiological characteristics in children with bifid rib. Methods: Nine children with the diagnosis of bifid rib between 2005 and 2010 were reviewed. Chest radiography and computed tomography (CT) were performed in all patients, and 3‐D images were additionally reconstructed in six patients. Results: Five girls and four boys with a mean age at presentation of 4.2 years had various types of unilateral bifid rib. Seven patients complained of a chest wall mass, whereas two patients whose costal abnormalities were incidentally detected on chest radiography were asymptomatic. Bifid ribs were confirmed on plain radiographs in six patients, while the other three patients were finally diagnosed on reconstruction 3D‐CT. One patient with a flared rib on a radiograph showed bifurcation of the costal cartilage on 3D‐CT. The other two patients with upper rib abnormalities on radiography had downward extension of the cervical or first rib articulating with the upper branch of the bifid first or second rib, respectively. Conclusion: Reconstruction 3D‐CT can demonstrate complicated thoracic abnormalities in patients with atypical appearance of the rib on plain radiographs. An isolated bifid rib may require no further intervention.     

先天性脊柱畸形合并泌尿生殖系统畸形发病情况及相关因素分析

目的 了解先天性脊柱畸形患儿中泌尿生殖系统畸形的发生率并探讨其与多种因素之间的联系.方法 选取2003年3月至2008年11月入院治疗的425例先天性脊柱畸形患儿,术前均行腹部B超了解泌尿生殖系统畸形情况、行脊柱CT了解脊柱畸形及脊柱内神经畸形、行心电图除外心脏异常,出现阳性结果行MRI及超声心动网以确诊.结果 先天性脊柱畸形患儿中泌尿生殖系统的发生率为11.8%(50/425),其发病与胎次、母亲年龄、出生地差异、脊柱畸形的分类、侧弯部位、侧弯方向以及是否合并心血管畸形、椎管内神经系统畸形均无统计学关系.泌尿生殖系统畸形的患儿出生时父亲年龄较无泌尿生殖畸形的患儿父亲年龄大(P=0.018),合并泌尿生殖系统畸形的患儿较易合并肋骨畸形(P=0.011).结论 先天性脊柱畸形患儿合并泌尿生殖系统畸形的发生率较高,需引起临床高度重视,从而给予适当处理.