Uses of Spinal Ultrasonography in diagnosis of occult and manifest spinal cord malformation in neonates and infants

Uses of Spinal Ultrasonography in diagnosis of occult and manifest spinal cord malformation in neonates and infants

Hagar Abdelrahman Mahammed Reda¹ & Hosny Mohammed Ahmed El Masry¹ & Mohammed Abo-Alwafa Aladawy¹ &  Tarek Mohammed M. Mansour² & Ahmed Y. Elamir³.

¹ Pediatrics and Neonatology ² Radiodiagnosis Departments, Faculty of Medicine, Al-Azhar University, Assiut.

 ³ Radiodiagnosis Department, Faculty of Medicine, Cairo University.

*Corresponding Author: Hagar Abdelrahman Mahammed Reda

E-Mail: hagaeabdelrahman99@gmail.com   

Mobile:01069062985.

Abstract

Background: Spinal dysraphism refers to a spectrum of congenital anomalies characterized by incomplete fusion of midline parenchymal bony and neural elements of the spine. Although Magnetic Resonance Imaging (MRI) has always been the imaging gold standard in neonates and infants with suspected spinal and paraspinal anomalies; spinal Ultrasound is becoming remarkably accepted as a first-line inexpensive and easily performed screening imaging modality used in neonates suspected of spinal dysraphism.

Aim: To evaluate the role of ultrasonography in diagnosis of neonates and infants with occult and manifest spinal cord malformations.

Patients and Methods: This is a prospective cross sectional diagnostic study that included 30 patients presented with clinical suspicion of spinal dysraphism, they were recruited from NICU, out-patient clinic and in-patient wards of the Pediatric Department of Al-Azhar Assiut University Hospital during the period from 1^st of November 2022 to 30^th of August 2023.

Results: Spinal US has 100% sensitivity, 100% specificity for detection of Myelocele, Myelocystocele and Distomatomyelia. Spinal US has 80% sensitivity, 100% specificity for detection of spinal lipoma and 71.4% sensitivity, 100% specificity for detection of segmental spinal dysgenesis and Dermal Sinus Spinal US has 83.3% sensitivity, 100% specificity for detection of Tethered Cord. Spinal US has 75% sensitivity, 100% specificity for detection of Caudal regression syndrome. Spinal US has 50% sensitivity, 100% specificity for detection of Lipomyelomeningocele.

There is statistically significant high agreement between MRI and US findings with 100% agreement in Myelocystocele and Distomatomyelia despite that spinal lipoma was detected in 5 cases by MRI and only in 4 case by US, segmental spinal dysgenesis was detected in 7 cases by MRI and only in 5 cases by US and Tethered Cord was detected in 6 cases by  MRI and only in 5 cases by US, Lipomyelomeningocele was detected in 4 cases by MRI and only in 2 cases by US, Dermal sinuswas detected in 7 cases by MRI and only in 5 cases by US, and Caudal regression syndrome was detected in 4 cases by MRI and only in 3 cases by US.

Conclusion: Ultrasound is an inexpensive, easily performed, widely available, radiation free investigative technique. It’s considered being the initial imaging modality of choice for detection of spinal dysraphism in neonates and infants up to 6 months of age. Ultrasound has good sensitivity and specificity especially myelocystocele, dismatomyelia compared with spinal MRI which is the gold standard for detection of spinal dysraphism. Spinal sonography also carries therapeutic applications and is useful as an image guidance modality for certain procedures

Keywords: Spinal Ultrasonography, Spinal dysraphism, occult and manifest spinal cord malformation.

Introduction:

Congenital malformations of the spinal cord are collectively termed spinal dysraphisms (SDs) These conditions are usually diagnosed at birth or in early infancy, but some may be discovered in older children or adults The estimated incidence of spinal dysraphism is about 1–3/1000 live births SDs are categorized into open spinal dysraphisms (OSDs), in which  there is an exposure of abnormal nervous tissues through a skin defect, and closed spinal dysraphisms (CSDs), in which there is continuous skin covering over  the underlying malformation open spinal dysraphisms  includes meningomyelocele (MMC) and other rare abnormalities such as myelocele, hemi myelomeningocele and hemi myelocele are always associated with a Chiari II malformation. Closed spinal dysraphisms are further divided into two subsets based on whether a subcutaneous mass is present in the low back closed spinal dysraphisms with mass comprises lipomyelocele, Lipomyelomeningocele, meningocele, and myelocystocele (Venkataramana NK 2011).

Closed spinal dysraphism without mass comprises simple dysraphic states (tight filum terminale, filar and intradural lipomas, persistent terminal ventricle, and dermal sinuses) and complex dysraphic states. The latter category involves abnormal notochordal development, either in the form of failed midline integration (ranging from complete dorsal enteric fistula to neurenteric cysts and diastematomyelia) or in the form of segmental agenesis (caudal agenesis and spinal segmental dysgenesis (Venkataramana NK 2011).

The diagnosis of open spinal dysraphisms is clinically obvious and postnatal Ultrasonography screening should be avoided because of the high risk of infection, whereas closed spinal it is usually made aware by the variable cutaneous Stigmata, including abnormal hair tufts, skin pigmentation, cutaneous hemangiomas, sinus openings, or subcutaneous masses (Orman G, et al 2019).

 The associated relationship between cutaneous stigmata and closed spinal dysraphisms has been long described and relies on the intimacy of their embryological origin. The presence of cutaneous stigmata allows for timely identification of spinal dysraphism (Ausili E, et al 2018).

There is an analogous relation between patients with anorectal malformations and associated congenital anomalies of the VACTERL spectrum. The spectrum of congenital anomalies incorporates spinal and/or vertebral defects (V), anorectal malformations (A), congenital cardiac anomalies (C), esophageal atresia/tracheoesophageal fistula (TE), renal and urinary abnormalities (R), and limb lesions (L). The association between spinal dysraphism and anorectal malformations has been reported to be up to 46%. Hence, patients with ARM are screened at birth to detect possible associated spinal dysraphism anomalies. Neonates with ARM are usually screened by spinal Ultrasonography   and confirmed by spinal MRI (Totonelli G, et al 2019).

Early identification of spinal dysraphism is crucial to avoid irreversible consequences such as neurological damage in tethered cord syndrome (Aby J,  et al 2020).

Neuro imaging of the spinal axis plays an immense role in the detection and classification of wide spectrum of SD anomalies (Kommana SS, et al 2019).

Ultrasonography, being a safe portable bedside imaging tool that requires neither sedation nor radiation, is rendered a valuable first-line screening modality in neonates with suspected spinal anomalies and is widely accepted by parents. The familiarity with the Ultrasonography   findings in neonates with spinal developmental anomalies is of great importance (Orman G, et al 2019).

The lack of ossification of the posterior spinal elements before 6 months of age presents a superior acoustic window for the delineation of the spinal axis, its canal content, and surrounding tissues (ValenteI, et al 2019).

MRI is the gold standard for radiological imaging of spinal dysraphism, yet it is still limited by its high cost and restricted availability, as well as the requirement of sedation in most children. Regardless these limitations, MRI are still the most preferable imaging tool particularly in those patients with high pretest probability for spinal dysraphism (Ausili E, et al 2018).

The American Institute of Ultrasound in Medicine (AIUM) guideline lists the following indications for the ultrasound examination of the neonatal spine:

• Lumbosacral stigmata known to be associated with spinal dysraphism.
• Evaluation of suspected defects such as cord tethering, diastematomyelia, hydromyelia, and syringomyelia.
• Spectrum of caudal regression syndrome (e.g., anal atresia or stenosis; sacral agenesis).
• Detection of sequelae of injury (e.g., hematoma after spinal tap or birth Injury; posttraumatic leakage of CSF; and sequelae of prior instrumentation, infection, or hemorrhage).
• Visualization of hemorrhagic fluid within the spinal canal in neonates and infants with Intracranial hemorrhage.
• Guidance for lumbar puncture.
• Postoperative assessment for cord retethering.
• Amongst the spinal dysraphism, ultrasound is usually not preferred in the open spinal dysraphism because of risk of infection (AIUM 2022).

Aim of the work:

To evaluate the role of ultrasonography in diagnosis of neonates and infants with occult and manifest spinal cord malformations.

Ethical consideration:

1. Our study was approved by the ethical committee of Faculty of Medicine, Al-Azhar University, Assiut, and conducted in accordance with Helsinki standards 2013.
2. An informed consent was obtained from all parents and participating children.
3. The results and data of the study are confidential, and the patient has the right to keep it.

4.The authors received no financial support for the research, authorship, and/or publication of this article.

5. No conflict of interest regarding study or publications

The sample size:

Our sample was estimated using the Everald’s equation for power calculation in diagnostics tests. Assuming the expected lowest sensitivity (SN) to be 95%, the lowest expected specificity (SP) to be 80%, confidence interval (W) for both sensitivity and specificity to be 5% and prevalence of spinal dysraphism to be (1-3 of 1000 live birth Venkataramana NK 2011) was done.

Sample size n = [DEFF*Np(1-p)]/ [(d2/Z21-α/2*(N-1) + p*(1-p)].

The calculated sample size is 30 patients, it was calculated using OpenEpi tool, Version 3, open-source calculator SSPropor (OpenEpi - Toolkit Shell for Developing New Applications). Confidence limits as % of 100 (absolute +/- %) (d): 5

Inclusion criteria:

• Neonates and Infants less than 6 months of age with closed spinal dysraphism or older with large bony spinal defect which permits passage of ultrasonography beam with proper visualization of intraspinal contents presenting with back cutaneous stigmata, which include: High-risk dimples (greater than 5 mm in diameter and more than 2.5 cm above the anus), palpable subcutaneous mass, haemangioma/ skin pigmentation, skin tags or tails, hairy patches, sinus tracts.

Exclusion criteria:

• Infants with open spinal dysraphism, infants older than 6 months of age with no large spinal defect (hindering proper visualization of intraspinal contents)

Methods:

This is a prospective cross sectional diagnostic study that included 30 patients presented with clinical suspicion of spinal dysraphism, they were recruited from NICU, out-patient clinic and in-patient wards of the Pediatric Department of Al-Azhar Assiut University Hospital during the study period from 1^st of November 2022 to 30^th of August 2023.

The patients were subjected to thorough history taking and full clinical examination including:

1. History: Age, sex and site of dysraphism.
2. General examination, local back examination (cutaneous stigmata), orthopaedic examination (Scoliosis) and neurological examination (urinary bladder, bowel).
3. Radiological investigation including:

Plain X-ray LSS, dedicated anorectal study, Spinal Ultrasound and Spinal MRI.

    Spinal ultrasonography examination: we followed the AIUM (American Institute of Ultrasound in Medicine) Practice Parameters; Neonatal and Infant Spine, (2022).

Equipment specification: Ultrasonography Grayscale examination with device that is equipped with 5-12MHZ linear array transducer (Siemens acuson 300) In AL-Azhar Assiut Univ. Hospital

Technique: The spinal cord was examined in both longitudinal and transverse planes taking into account the images shown on the left and right adequate thick Ultrasound gel layer was used to assess the superficial soft tissue and skin surface for the presence of any tract.

Sterile Ultrasound gel with a sterile probe cover was utilized in cases where the skin dose not intact to avoid the risk of infection.

Panoramic imaging views of the entire spinal canal have also been really helpful in demonstrating a full anatomical overview along with the relationship between the spinal cord and the vertebral column, as well as high lighting the level of the conus within the theca Sonography of the spine should be performed with a high frequency (5–12 MHz), high resolution linear transducer Both axial and sagittal plane scanning is mandatory the axial scanning can either be performed in a cranial to caudal direction or caudocranial direction.

Localization of the conus medullaris is crucial for the detection of low lying cord or high termination of cord Location of conus should be interpreted in relation to the lumbar vertebral bodies Sagittal scanning should be performed both in the median and paramedian planes.

Statistical analysis:

Data collected were reviewed and coded. These numerical codes were fed to the computer where statistical analysis was done using the Statistic Package for Social Science Version 25 (SPSS 25).

1. A) Descriptive statistics:

• Quantitative data: were presented as mean and standard deviation (mean ± SD)
• Qualitative data: were expressed as numbers and percentage

1. B) Analytical statistics

Comparing groups was done using

• Chi square-test (X²): for comparison of qualitative data.
• Student's "t" test for comparison of quantitative data of 2 independent sample with normal distribution variables.
• One-way ANOVA test for comparison of quantitative data of more than 2 independent sample with normal distribution variables.
• ROC curve was plotted to determine sensitivity and specificity of the studied variable to predict the outcome.

The coefficient interval was set to 95%. The level of significance was calculated according to the following probability (P) values:  P<0.05 was considered statistically significant.

Results:

All results will be presented in the following tables and figures:

Table (1): Demographic data and Clinical presentation of participating neonates and infants with clinical suspicion of dysraphism (n= 30).

Qualitative data are presented as number (percentage).

Table (1) Shows the demographic data and clinical presentation of participating neonates and infants with clinical suspicion of dysraphism. 36.7% was Lumbosacral, 30% Lumbar, 23.3% Sacrococcygeal and 10% Dorso-lumbar dysraphism. 63.3% of patients presented with back cutaneous stigmata, 33.3% presented with anorectal malformation and only 1 case (3.3%) presented with congenital scoliosis. 

Table (2): Ultrasound findings of spinal dysraphism in the studied neonates and infants (n= 30).

Qualitative data are presented as number (percentage).

Table (2) Shows that in cases with occult/closed dysraphism; Ultrasound examination demonstrated Tethered cord in 16.7%, Spinal lipoma in 13.3%, Dermal sinus in 10%, Distomatomyelia with segmental spinal dysgenesis       in 10%, Caudal regression syndrome in 10%, Lipomyelomeningocele with associated dermal sinus in 6.7%, Myelocystocele in 6.7% and Segmental spinal dysgenesis in 6.7%.

Table (3): MRI findings of spinal dysraphism in the studied neonates and infants (n= 30).

Qualitative data are presented as number (percentage).

Table (3) Shows that in cases with occult/closed dysraphism, MRI examination demonstrated isolated Tethered cord and Lipomyelomeningocele with associated dermal sinus 13.3% for each, Dermal sinus, Distomatomyelia with segmental spinal dysgenesis, Spinal lipoma in 10% for each, Caudal regression syndrome, Segmental spinal dysgenesis , Caudal regression syndrome with spinal lipoma in 6.7% for each, Myelocystocele with segmental spinal dysgenesis, Myelocystocele with tethered cord, and Tethered cord with segmental spinal dysgenesis in 3.3% for each. 

Table (4): Comparison between US and MRI findings regarding each subtype of spinal dysraphism

Qualitative data are presented as number (percentage), c²: Chi square test, p: p value for comparing between the studied groups and * for statistically significant p value.

This table shows Comparison between US and MRI findings regarding each subtype of spinal dysraphism

Table (4) Shows that  there is statistically significant high agreement between MRI and US findings with 100% agreement in Myelocystocele and Distomatomyelia, despite that Spinal lipoma was detected in 5 cases by MRI and only in 4 case by US, Segmental spinal dysgenesis was detected in 7 cases by MRI and only in 5 cases by US and Tethered cord was detected in 6 cases by MRI and only in 5 cases by US, Lipomyelomeningocele was detected in 4 cases by MRI and only in 2 cases by US, Dermal sinus was detected in 7 cases by MRI and only in 5 cases by US, and Caudal regression syndrome was detected in 4 cases by MRI and only in 3 cases by US. However, the agreement between MRI and US findings was statistically significant.

Figure (1): Ten months old female presented by patchy of hair at lumbosacral region no history of NICU addmition. Spinal ultrasound findings: (A) Sagittal MRI T2 demonstrates tethered cord ends at L3 vertebral body level (White arrow), (B) Photo of the lower back shows hairy skin, smal skin hemangioma and (C) A longitudinal ultrasound image shows a low-lying elongated conus.

Table (5): Sensitivity and specificity of US for detection of each subtype of spinal dysraphism

PPV: Positive predictive value, NPV: Negative predictive value

Qualitative data are presented as number (percentage).

Figure (2): Receiver Operating Charchterstics (Roc) curve for US sensitivity and specificity for detection of each Subtype of spinal dysraphism.

Table (5) & Figure (2):  Shows that Spinal US has 100% sensitivity, 100% specificity for detection of Myelocele, Myelocystocele and Distomatomyelia. Spinal US has 80% sensitivity, 100% specificity for detection of Spinal lipoma and 71.4% sensitivity, 100% specificity for detection of segmental spinal dysgenesis and Dermal sinus. Spinal US has 83.3% sensitivity, 100% specificity for detection of Tethered cord,75% sensitivity, 100% specificity for detection of Caudal regression syndrome, 50% sensitivity, 100% specificity for detection of Lipomyelomeningocele.

Discussion:

In neonates and infants with suspected spinal and paraspinal anomalies, magnetic resonance imaging was and remains the imaging gold standard. However, ultrasonography has recently witnessed tremendous improvement in image quality with the advent of new generation high frequency ultrasound scanners that have brought its diagnostic value on par with that of MRI (Nair N, et al 2016).

The current study was conducted on 30 patients presented with clinical suspicion of spinal dysraphism to evaluate the role of US in diagnosis of neonates and infants with occult and manifest spinal cord malformations.

According to the demographic profile, the age of our study group ranged between 1 month to 6 month of age in 46.7% of the included infants, 1 day to 29 days in 33.3% and > 6 months in 20% of the included infants. Most of the included neonates with spinal dysraphism were females (53.4%).

As regards the clinical presentation of spinal dysraphism in our study; 63.3% had back cutaneous manifestations in the form of dimple (20%), hair tuft (13.3%), skin discoloration (10%), skin tag (6.7%), cystic back swelling (6.7%), fatty back swelling (3.3%), hemangioma (3.3%), anorectal malformation (33.3%) in the form of recto-urethral fistula (10%), imperforate anus (10%), rectovaginal fistula (6.7%), rectal atresia (3.3%) and clocal malformation (3.3%), and finally congenital scoliosis (3.3%).

Another study by Kumari et al. 2016 which was conducted on 66 infants ranged between 17 days to 13 years; most of the children were ≤2 years old. Fourty (66.6%) patients were females and 26 (33.3%) were males. They found that swelling in the back was the commonest clinical feature (77.2%).

Ramacharya et al. 2015 studied 50 patients with spinal dysraphism and found the age of presentation ranged from 2 m to 16 years and also showed that spinal dysraphism was common in young females.

Kumari et al. 2016 reported in their study of 155 patients the mean age of presentation was 5.7 years with 1.5:1 female to male ratio. Similarly, a previous Egyptian study by Mostafa A.K.A., et al. 2021 also revealed the mean age of presentation was 5.3 months with female predominance among children with spinal dysraphism.

Another study by Dhingani et al 2016 which was conducted on 38 cases of both sexes with spinal dysraphism and  found the age group of the studied patients ranged from 2 days to 16 years, and 84.21% were < 10 years, and the neonatal period was the most common presenting age group (39.47%), in addition the most common clinical finding at presentation was midline back swelling (60.53%), and the next common presentation was urinary incontinence (47.37%), followed by skin dimple in back (28.95%), fecal incontinence (21.05%), hair tuft (3.33%) and dermal sinus (3.33%).

The majority of the included neonates with spinal dysraphism had associated malformations (70%), in the form of hydrocephalus (26.6%), renal anomalies (13.3%), limb malformations (13.3%), cardiac anomalies (10%) and genitourinary anomalies (6.7%).

Another study by Hussein et al. 2022 was performed on 33 patients with spinal dysraphism to high light the associated spinal dysraphism radiological findings in patients with either ARM or back cutaneous stigmata and revealed non spinal anomalies confronted in their study were renal anomalies (40%), hydrocephalus (20%), lower limb anomalies (10%), genital anomalies (10%), cardiac anomalies (10%) and motor anomalies (5%).

Ruangtrakool et al. 2021 documented fecal incontinence, urinary incontinence, motor symptoms, gait abnormalities, and scoliosis in order of frequency. While Tawfik et al. 2020 found Neurological abnormalities, urinary incontinence, hydrocephalus, and Chiari malformation were commonest association.

In the current study; the commonest sites for dysraphism in participating infants were lumbosacral (36.7%), lumbar (30%), sacrococcygeal (23.3%), and dorsolumbar (10%). This goes in run with a previous Egyptian study by Tawfik et al. 2020 which was conducted on 45 infants and children with spinal cord anomalies and revealed the commonest was lumbosacral (71.1%).

Another study by Dhingani et al. 2016 showed the commonest site for spinal malformation was lumbosacral (52.63%) followed by sacrococcygeal (34.21%).

One of the major reasons for performing US is early detection of the possibility of tethered cord syndrome. A tethered cord syndrome is caused by a stretch induced dysfunction of the caudal spinal cord and conus, that often associated with spinal dysraphism (Michelson DJ, Ashwal S. 2004).

As regards ultrasonography findings in our study; the commonest was tethered cord (16.7%), followed by spinal lipoma (13.3%), dermal sinus (10%), distomatomyelia with segmental spinal dysgenesis (10%), caudal regression syndrome (10%), lipomyelomeningocele with associated dermal sinus (6.7%) and myelocystocele (6.7%).

Another study by Dhingani et al. 2016that was conducted on 38 cases with spinal dysraphism showed that most common anomaly was tethered cord seen in 23 (79.31%) patients, syrinx (62.06%), MMC (48.27%), and lipomyelomeningeocele (27.58%). Similarly, Nishtar et al. 2011 found that 2 of the studied 53 patients (4%) have diastematomyelia.

The current study revealed that the commonest MRI findings were tethered cord (13.3%), , lipomyelomeningocele with associated dermal sinus (13.3%), dermal sinus (10%), distomatomyelia with segmental spinal dysgenesis (10%), spinal lipoma (10%), caudal regression syndrome (6.7%), segmental spinal dysgenesis (6.7%), caudal regression syndrome  with spinal lipoma (3.3%), myelocystocele with segmental spinal dysgenesis (3.3%), myelocystocele with tethered cord (3.3%), tethered cord with segmental spinal dysgenesis (3.3%). Compared to another study by Mehta et al. 2017 which was conducted on fifty pediatric patients referred with clinical suspicion of spinal anomalies for MRI scan and revealed the commonest spinal dysraphism detected by MRI were type II Arnold Chiari malformation (34%), spina bifida occulta (22%), and diastematomyelia.

The current study revealed statistically significant association between diagnosis of segmentation/vertebral spine anomalies by either US and MRI with p-value=0.000. also, the current study found statistically significant agreement between US and MRI findings especially myelocystocele and Distomatomyelia with 100% agreement, while MRI was more in detecting other spinal anomalies than US especially lipomyelomeningocele, tethered cord, dermal sinus, segmental spinal dysgenesis and caudal regression syndrome. In agreement with Dhingani et al. 2016 study that showed 23 out of 29 patients (79.31%) had full agreement between spinal US and MRI examination, and 6 out of 29 patients (20.69%) showed partial agreement. In these six cases with partial agreement; spinal US missed tethered cord and syrinx in three cases, small lipomatous component in one case of lipomyelomeningeocele, one case of intra-dural lipoma, and one case of split cord associated with myelomeningocele.

Another study by Hughes et al. 2003 ultrasound showed full agreement with MRI in 6 of 15 patients (40%), partial agreement in 7 of 15 patients (47%) and no agreement in 2 of 15 patients. Ultrasound missed some findings in some cases as dorsal dermal sinuses, fatty filums, terminal lipoma, partial sacral agenesis, hydromyelia and low-lying cords. However, overall, in 12 of 13 (92%) cases with abnormal MRI, ultrasound identified at least one of the concurrent abnormalities. No agreement was found between ultrasound and MRI in two cases, one being false-positive and the other false negative. This resulted in an overall false negative diagnosis in one of 12 patients (8%) with abnormal MRI and an overall false positive diagnosis in one of 3 patients with a normal MRI.

Spinal US has less sensitivity compared to MRI in detecting closed type of spinal anomalies or other findings associated with primary anomaly, various vertebral anomalies and kyphoscoliotic deformity. MRI is also superior in identifying the exact extent of detected anomaly such as intraspinal extension of lipomatous tissue; the level, extent and type of split cord; extent of vertebral agenesis, and shape and level of conus termination in case of caudal regression syndrome (Tawfik NA, et al 2020).

The current study revealed that spinal US had 83.3% sensitivity, 100% specificity, 100% PPV, 96% NPV and 96.7% accuracy in detection of tethered cord. Another study by Ben-Sira et al. 2009 was performed on 50 neonates with lumbar skin stegmata to reassess the utility of ultrasound in infants with lumbar skin stegmata that may be associated with tethering spinal cord and revealed that US had excellent sensitivity 96%, specificity (96%) and positive predictive value (96%) overall compared with MRI and concluded the reliability of US as a screening tool for tethered cord syndrome.

Tethered spinal cord is important to diagnose because it may lead to secondary skeletal defects (e.g. talipes cavus), neurological defects of the lower limbs, or autonomic neuropathy affecting the bladder or bowel (Hughes JA, et al 2003).

       The current study revealed that spinal US had 100% sensitivity, 100% specificity, 100% PPV, 100% NPV and 100% accuracy in detection of myelocystocele. spinal US had 50% sensitivity, 100% specificity, 100% PPV, 92.8% NPV and 93.3% accuracy in detection of lipomyelomeningocele. In agreement with Dhingani et al. 2016 study which also revealed good correlation between spinal US and MRI findings for detecting primary dysraphic lesions as meningomyelocele and lipomeningomyelocele.

Conclusion:

• Ultrasound is an inexpensive, easily performed, widely available, radiation free investigative technique.
• Ultrasound now considered being the initial imaging modality of choice for detection of spinal dysraphism in neonates and infants up to 6 months of age.
• The most common clinical presentation of spinal dysraphism is back cutaneous manifestations in the form of dimple, hair tuft, skin discoloration, back swelling.
• The majority of cases with spinal dysraphism have associated malformations in the form of hydrocephalus; renal anomalies   limb malformations, cardiac anomalies and genitourinary anomalies.
• The commonest US finding was tethered cord.
• Ultrasound has good sensitivity and specificity especially myelocystocele, dismatomyelia compared with spinal MRI which is the gold standard for detection of spinal dysraphism.
• Spinal sonography also carries therapeutic applications and is useful as an image guidance modality for certain procedures.

Recommendations:

     In neonates and infants suspected to have spinal dysraphism, ultrasound imaging of spinal channel is performed, where ultrasound reveals changes that indicate spinal dysraphism, an MRI is needed as soon as possible. If US results are normal, we continue with the treatment within the framework of differential diagnostic possibilities and decide on need for MRI according to the clinical picture.

Limitations:

• The small sample size: Neonates and infants were chosen from a single center and further investigations as genetic study could not be done because the facility was not available in our hospital.
• Funding: None.

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