template reporting: an attempt to simplify the spinal dysraphism jargon · 2021. 4. 22. ·...

RADIOLOGY | ORIGINAL RESEARCH

TEMPLATE REPORTING: AN ATTEMPT TO SIMPLIFYTHE SPINAL DYSRAPHISM JARGON

Nilkanth Laxman Pal∗, Ambika Sumeet Juwarkar∗∗,1, Zarina Abdul Assis� and Sanjaya Viswamitra4∗Department of Radio-diagnosis, Sri Sathya Sai Institute of Higher Medical Sciences, Whitefield, Bengaluru, Karnataka, ∗∗Department of Radio-diagnosis,GoaMedical College, Bambolim-Goa, 403 202 India, �Department of Radio-diagnosis, Sri Sathya Sai Institute of Higher Medical Sciences, Whitefield, Bengaluru,

Karnataka, 4Department of Radio diagnosis Sri Sathya Sai Institute of Higher Medical Sciences, Whitefield, Bengaluru

ABSTRACT OBJECTIVES: 1. To approach cases of suspected spinal dysraphism in a systematic manner and categorizethem according to the classification available in literature. Enumerate all the ancillary findings which are associated witheach malformation. 2. To provide a template with checklist for reporting a case of spinal dysraphism. 3. To reinforcethe diagnostic accuracy of Magnetic Resonance Imaging (MRI) in characterizing various congenital disorders of spine.Material and Methods:This Retrospective observational study comprising 100 patients was conducted at the tertiaryinstitution using data collected from the PACS system over 5 years (January 2009 - January 2014). Results: Cases of spinaldysraphism were classified into open and closed types (ratio:1:3.2). The most common type of open spinal dysraphism inour study was myelomeningocele (20%). Closed spinal dysraphism were subcategorized based on presence or absenceof subcutaneous mass. In our study, the most common types of closed dysraphisms were lipo-myelomeningoceles(22%) and diastematomyelia (22%). Numerous other MRI findings are associated with each case of spinal dysraphismlike syrinx, tethered cord, vertebral segmentation anomalies, spinal curvature abnormalities and Chiari malformation.Tethered cord (86%) was the most common associated finding in our study. Conclusions: Mention of the type of spinaldysraphism and all the associated findings in the preoperative MRI report is crucial for surgical planning. Templatereporting helps to report each case systematically and confidently.

KEYWORDS Reporting Template, Diastematomyelia, Dorsal dermal sinus, Spinal dysraphism, Spinal lipomas,Myelomeningocele, Myelocele

Introduction

Spinal dysraphism is defined as incomplete or absent fusion ofmidline neural, mesenchymal and cutaneous structures due toincomplete closure of the neural tube during development [1,2].

Spinal dysraphism has for long been an intriguing subject forclinicians and radiologists alike. A major spinal malformation

Copyright © 2021 by the Bulgarian Association of Young SurgeonsDOI:10.5455/ijsm.spinal-template-reportingFirst Received: January 15, 2021Accepted: February 14, 2021Associate Editor: Ivan Inkov (BG);1Department of Radio-diagnosis, Goa Medical College, Bambolim-Goa, India. 403202, Email: [email protected]

is like the iceberg’s tip and is associated with the bewilderingrange of other ancillary findings. An explicit description ofall the anomalies in an MRI report is crucial for preoperativesurgical planning.

Freestyle reporting overwhelms the clinician with a magni-tude of unstructured MRI findings. Template reporting willprovide a checklist to enumerate all the findings, presenting thedata in a methodical format for the radiologist to report andthe clinicians to interpret. Such a template will reduce the timerequired for reporting without missing out on any importantdetail.

Material and Method

The study was commenced following institutional ethical clear-ance. The informed consent waived off by the ethical commit-

Nilkanth Laxman Pal et al./ International Journal of Surgery and Medicine (2021) 7(2):45-55

ted due to the retrospective nature of the study. We reviewedrecords of 100 patients at our institute in the Department ofRadio-diagnosis and Imaging, using data collected from thePACS system over five years (January 2009 - January 2014). Thedata included 1patients who had undergone routine MRI ex-amination in our institution, irrespective of their age and sex.All MRI cases were performed on 1.5 Tesla GE SIGNA HORI-ZON CV/NVI systems, using the standard coils. The protocolincluded were T1, T2 sequences in sagittal, axial and coronalplanes; FAT saturation and contrast scans were performed when-ever needed (E.g. lipomas, dermoid, epidermoid, abscesses, andmeningitis). Diffusion restriction was performed in suspectedcases of epidermoid. All cases were reported by experienced ra-diologists. All images are interpreted on synapse PACS (Fujifilm)and MRI console monitor (Signa horizon; GE) with adequategrey-scale center level and window width settings. In patientswho underwent surgery, the MRI findings were compared withthe operative notes available. The histopathological diagnosiswas retrieved from the Department of Pathology, SSSIHMS, Ben-galuru. The data was presented in the form of numbers andpercentages.

Results

The study group comprised 100 patients out of 48 were males,and 52 were females with F: M = 1.1. The peak age of presen-tation was below 10 yrs of age (70%), 20% of patients were inthe age group between 11-20 yrs and only 10 % of patients wereabove 20 yr of age. The most common presenting symptom inour study was a lump at the back (71%). This highlights the needfor a detailed systematic examination of the newborn babies todetect the neural abnormalities. Age plays a crucial role be-cause neurological deterioration occurs with advancing age [3].Also early detection and correction of the curvature abnormalityimproves patient’s outcome [4]. Other presenting complaintsincluded bladder/bowel disturbances- 46% (incontinence, neu-rogenic bladder, hydronephrosis, anal malformations, constipa-tion), weakness - 34%, orthopaedic deformities - 31% (such asshort leg, varus deformity, CTEV, flat foot), raised intracranialpressure - 29%, cutaneous stigmata - 20%, developmental delay- 12% and sensory symptoms - 6% (loss of sensation, tinglingnumbness, trophic ulcer, etc). Overall most common locationof dysraphism was in the lumbar region (36.4%) followed bylumbosacral region (31.8%).

The anomalies detected are listed in Table no 1. Cases ofspinal dysraphism were classified into open and closed based onthe presence or absence of exposed neural placode with skin de-fect[5,6]. Myelomeningocele was the most common type of opendysraphism. In our study, the number of closed dysraphismcases outnumbered the open ones. The ratio of closed to opendysraphisms was 3.2:1. The skewed ratio could be attributedto the fact that open spinal dysraphism is visible at birth andrequires immediate intervention to avoid complication. Henceuntreated myelomeningocele is rarely referred for imaging. Theusual role of radiology in cases of open spinal dysraphism is toelucidate the cause for late deterioration due to certain knowncomplication after primary repair of the myelomeningocele [7,8].

Closed dysraphism were further subcategorized based onpresence or absence of the subcutaneous mass as proposed byTortori Donati [5], which is extremely helpful in day-to-day re-porting. In the present study, the subcutaneous mass was foundin 42 patients out of a total of 76 patients with closed dysraphism(55.3%). The most common type of closed spinal dysraphism

Table 1 Distribution of types of dysraphisms along with theirrespective sex ratios.

Male Female Total

Noofcases

% Noofcases

%

Myelomeningocele 10 50.0 10 50.0 20

Myelocele 4 100 - - 4

Lipomyelomeningocele 6 27.3 16 72.7 22

Lipomyelocele 5 41.7 7 58.3 12

Meningocele 6 75.0 2 25.0 8

Dorsal dermal sinus 6 60.0 4 40.0 10

Diastematomyelia 10 45.4 12 54.5 22

Intradural lipoma 0 0 5 100.0 5

Caudal regressionSyn.

3 50.0 3 50.0 6

Dermoid 2 50.0 2 50.0 4

Epidermoid 1 33.3 2 66.6 3

Filar lipoma 10 100 8 100 18

Tight filum terminale 3 100 0 0.0 3

Neurenteric cyst 0 0 1 100 1

presenting with a subcutaneous mass was lipomyelomeningo-coele as presented in Table 2. The most common closed spinaldysraphism without any subcutaneous mass was split cord mal-formation.

In the present study, the tethered cord was the most commonassociated abnormality found in 86 % of patients, followed bysyrinx, vertebral segmentation anomalies and Chiari malforma-tions. Table No 3 denotes the dysraphic anomalies associatedwith tethered cord.

Syrinx was most commonly associated with various anoma-lies as listed in Table No. 4. Diastematomyelia was most com-monly associated with a syrinx and caudal regression anomaliesbeing least commonly associated with a syrinx.

In the present study, spina bifida was the commonest bonyvertebral segmentation anomaly (84%), followed by block ver-tebrae (19%), hemivertebrae (18%), butterfly vertebrae (12%)and coronal cleft (3%). We also had six patients with caudalregression syndrome. In the present study, spinal curvature ab-normalities comprising scoliosis and kyphosis were detected in27% of patients.

Chiari malformation is seen in almost all cases of open spinaldysraphism (100%)[9].

Among the 100 patients enrolled in our study, 54 patientsunderwent surgery in our institution. MRI findings mentionedin the report correlated with the operative details available.

Discussion

MRI undisputedly is the modality of choice for imaging in spinaldysraphism [6,10]. It provides excellent soft-tissue contrast, andits role has been well documented in previous research articles.


Table 2 Data regarding spinal lipomas in our study is tabulated in the following table.1.

Male Female

No of cases % No of cases %

No of cases 22 12 5 18 57

Sex

• Males 6 5 0 10 21

• Females 16 7 5 8 36

Clinical features

• Swelling 23 12 4 8 47

• B/B disturbance 13 4 4 3 24

• Orthopaedic 4 2 1 4 11

• Weakness 9 4 1 6 20

• Sensory 2 0 2 1 5

• Raised ICP 7 3 0 5 15

• Dev. Delay 3 1 0 2 6

• C. Stigmata 4 4 0 5 13

Subcutaneous mass 22 12 4 8 46

TC 22 12 5 17 56

Syrinx 4 4 0 9 17

Scoliosis 5 0 1 7 13

VSA

• Spina bifida 22 12 0 13 47

• Hemivertebra 4 0 0 5 9

• Block vertebra 3 2 1 2 7

• Butterfly vert. 0 0 0 4 4

• Coronal cleft 0 0 0 0 0

Associated findings.Chiari malformation, Neurenteric cyst, Caudal regression syndrome,

Dorsal dermal sinus and diastematomyelia(B/B – Bowel/bladder disturbances. ICP – Intracranial pressure. TC –Tethered cord.VSA – Vertebral segmentation anomalies. C.Stigmata – Cutaneous stigmata. LMMC —

Lipomyelomeningocele. LMC — Lipo-myelocele)


Table 3 Disorders associated with tethered cord

Types No ofcases(n=86)

Percentage

Myelomeningocele 20 23.52

Myelocele 4 4.70

Lipomyelomeningocele 22 25.58

Lipomyelocele 12 14.11

Meningocele 5 5.88

Dorsal dermal sinus 7 8.23

Diastematomyelia 17 20.0

Intradural lipoma 5 5.88

Caudal regressionSyndrome

4 4.70

Dermoid 3 3.52

Epidermoid 1 1.17

Filar lipoma 17 20.0

Tight filum terminale 3 3.52

Neurenteric cyst 1 1.17(B/B – Bowel/bladder disturbances. ICP – Intracranial pressure. TC –Tetheredcord.VSA – Vertebral segmentation anomalies. C.Stigmata – Cutaneous stigmata.LMMC — Lipomyelomeningocele. LMC — Lipo-myelocele)

Table 4 Disorders associated with syrinx

Types No ofcases(n=46)

Percentage

Myelomeningocele 10 29.41

Myelocele 1 2.90

Lipomyelomeningocele 4 14.7

Lipomyelocele 4 11.7

Meningocele 2 5.80

Dorsal dermal sinus 2 5.80

Diastematomyelia 13 38.2

Caudal regressionSyndrome

1 2.90

Filar lipoma 9 26.4

Figure 1: Myelomeningocele. Axial T2 weighted MR image(Fig.1A) and Axial schematic diagram (Fig. 1B) show neuralplacode (thick arrow). This neural placode is exposed to envi-ronment and not covered by skin or fat. Note that placode isprotruding above the skin surface due to enlarged subarachnoidspace (star). Neural elements are marked by thin arrow in Fig1A. These features are characteristic for myelomeningocele.

The definitions and classification of spinal dysraphism into itsvarious subtypes has been well reckoned in literature [1,6,11,12].We approached each case of suspected spinal dysraphism usingthe categories described previously in a systematic manner [6].

Description of the principle malformation:

We approached each of our cases in the following manner todelineate the principle malformation. The principle malforma-tion was categorized based on presence or absence of skin defectinto open or closed type, i.e. whether neural placode is exposedto exterior or not[1,6,11,12]. On MRI, neural placode is seen asplaque-like soft tissue thickening with defective overlying skinand interrupted subcutaneous fat. Neural tissue (like tetheredcord, nerve roots) will be seen reaching up to the neural placode.

The cases of open spinal dysraphism were subclassified onMRI based on the relationship of the neural placode with theskin. If neural placode is elevated above the skin, it was labelledas myelomeningocele [Figure 1], and if the neural placode wasflushed with skin, it was labelled as myelocele[Figure 2]. In thecase of split cord malformation, either and/or both hemicordherniated producing hemimyelocele or hemimyelomeningocele[Figure 3] defined based on the above-stated criteria [5,13,14].

The cases of closed spinal dysraphism with intact overlyingskin were subdivided into two types based on the presenceor absence of swelling at the back[5]. While reporting MRI ofpatients presenting with a lump two important things to benoted are the contents of the swelling (fat, fluid, neural tissue)and the relationship of neural placode with the fat.

a) Swellings containing fat with neural placode-fat interface out-side the spinal canal were diagnosed as lipomyelomeningo-cele [Figure 4]. Similarly, fat-containing lesions with a neu-ral placode-fat interface within the canal were designatedas lipomyelocele [Figure 5]. In both these scenarios, thedura is deficient, and the intracanalicular fat is contiguouswith subcutaneous fat. It is important to note whether thefatty tissue has a smooth interface with the cord or whetherthere is the infiltration of the fat into the spinal cord, laterbeing difficult to operate[12,15].

b) Swelling containing only fluid is either meningocele (single


Table 5 Description of various vertebral anomalies.

1. Failure of fusion Description of the anomaly

a) Asomia Vertebral body not seen, posterior elements are present.

b) Wedge vertebra One half of vertebral body hypoplastic is producing a wedge defect.

c) Hemivertebra One half of the vertebral body fails to develop.

I. Fully Seg-mented

Disc present between hemivertebra and adjacent vertebral bodies.

II. Partially seg-mented

Hemivertebra is fused with one of the adjacent vertebra

III. Unsegmented Hemivertebra is fused with both the adjacent vertebra.

d) Butterfly Non-fusion of the left and right side ossification centers appreciated on coronal images.

e) Coronal cleft Gap/defect seen between the anterior and posterior half of the vertebral body on the sagittal image.

f) Pedicular anoma-lies

One side of the neural arch is absent or rudimentary with contralateral pedicle being enlarged.

g) Spina bifida The gap in the posterior neural arch

2. Disorders of seg-mentation

a) Block vertebra Adjacent vertebrae appear fused involving the body and posterior elements with no or rudimentarydisc between the two. At the site of fusion of the bodies, there is narrowing seen referred to as waistsign appreciated on coronal/sagittal images. The findings which help to differentiate a congenitalblock vertebra from acquired cause (like Koch’s) include waist sign and fusion of both body andposterior elements.

b) Unilateral unseg-mented bar

The fusion of body, disk space and facet joints of one or more adjacent vertebral levels on one side,other side being unfused.

c) LSTV Lumbarisation and sacralisation

3. Combined E.g. Unilateral segmental bar + hemivertebrae.

4. Segmental spinaldysgenesis

It is a rare congenital malformation in which an isolated segment of the spinal column and cord fails todevelop normally.

5. Caudal agenesis Type I and type II

fluid containing herniated sac)[2][Figure 6], terminal myelo-cystocele (meningocele + herniated syrinx within producingsac within sac appearance located at the terminal end ofthe cord)[16] or non-terminal myelocystocele (meningocele+ herniated syrinx located at the non-terminal end of thecord) [17].

Closed spinal dysraphism without subcutaneous mass wasdivided into simple and complex anomalies. These abnormal-ities are difficult to diagnosis during the routine clinical exam-ination because of the absence of obvious subcutaneous mass[5].

Split cord malformation/Diastematomyelia refers to sagittalspitting of the cord into two hemicord, divided into two types.In type I, each hemicord is contained in its own arachnoid/duralsheath with rigid osteocartilaginous septum separating the twohemicords[Figure 7]. In type II, two hemicords are envelopedin a single arachnoid/dural sheath separated by the non-rigidfibrous median septum, no bone spur[18][Figure 8]. Combi-

nation of spina bifida and intersegmental fusion of laminae ispresent in 60% of patients and is highly suggestive of the di-agnosis[15]. While reporting, we should comment about thelevel and length of splitting, type of diastematomyelia withbony or fibrous spur, attachment of the bone spur, level of conusmedullaris, associated syrinx, thickness of filum terminale andvertebral segmentation anomalies[18].

Dorsal dermal sinus [Figure 9] refers to epithelial lined tractlocated in midline extending from the skin surface inward forvariable distance[19,20]. While reporting the tract, things tobe mentioned include the location of the tract, the extent of thetract (subcutaneous, extradural, subarachnoid space, spinal cord,conus medullaris, filum terminale or the nerve roots), associatedpathologies with the tract (like lipomas, teratomas, dermoid[Figure 10], epidermoid, abscesses, meningitis), level of conusmedullaris, split cord malformation and other associated mal-formations like lipomyelocele/lipomyelomeningocele. Apartfrom routine imaging, additional sequences include contrast


Figure 2: Myelocele. Axial T2 weighted MR image (Fig.2A),Sagittal T2 weighted MR image (Fig.2B) and Axial schematicdiagram (Fig. 2C) show neural placode (thick arrow). Thisneural placode is exposed to environment and not covered byskin or fat. Also note that placode is flushed with skin surfacewithout enlargement of underlying subarachnoid space. Neuralelements are marked by thin arrow in Fig 2A. These features arecharacteristic for myelocele.

scan and diffusion-weighted images for appropriate indicationslike meningitis, epidermoid and suspected chemical meningitisdue to rupture of the dermoid/epidermoid. This tract usuallyappears hypointense on T1 and T2 sequences. T1 weighted se-quences thus best demonstrate the extradural component of thetract predominantly the subcutaneous part of the tract and T2sequence is useful for the intradural component of the tract. Anintradural portion of the tract is difficult to visualize[21,22].

Intradural lipomas [Figure 11] is seen as an intramedullarymass projecting outside to form subpial bulge with intact dura,mostly located along the dorsal aspect of the spinal cord[23].Filar lipomas [Figure 12] represent thick fatty filum more than2 mm in thickness. Filar lipomas may involve the intraduralportion of the filum, the extradural portion, or both[24].

Caudal regression syndrome denotes a combination ofanomalies such as partial agenesis of the lower spine, anomaliesof genitourinary tract, pulmonary hypoplasia, and/or defor-mities of the lower limbs. Two distinct groups identified. 2distinct groups identified. Group I – conus abruptly ends at ahigher level than normal with a large portion of bony sacrumbeing absent. In Group 2 - the conus ends below L-1, elongated,stretched caudally, and tethered with sacrum being relativelywell preserved[25].

Neurenteric cysts are located within the spinal canal. Theymay communicate with an extra spinal component of cyst in themesentery or mediastinum around a hemivertebra or througha butterfly vertebra, and/or they may attach by a fibrous stalkto the vertebra, mesentery, or gut. MR displays the cyst anddisplaced cord plus any bone abnormalities. The most common

Figure 3: Hemi-lipomyelomeningocele andHemimyelomeningocele. T1 weighted axial MR imagesshows splitting of the spinal cord into two hemicords (thinlong arrows) with formation of lipomyelomeningocele (arrowheads) arising from the right hemicord and formation ofmyelomeningocele (short arrows) arises from left hemicord.

Figure 4: Lipomyelomeningocele. Axial T2 weighted MR im-age (Fig.4A), Axial T1 weighted MR image (Fig.4B) and Axialschematic diagram (fig 4C) of lipomyelomeningocele. The neu-ral plate is covered by fat (F) and skin along its dorsal aspect.MRI images also show that placode–lipoma interface (arrows)lies outside the spinal canal due to enlargement of subarachnoidspace (star). F = Fat.

location is at a cervicothoracic junction or concerning the conusmedullaris[15]. Neurenteric cysts appear isointense to hyperin-tense on T1-weighted images and hyperintense on T2-weightedimages, presumably due to their high protein content, describedat surgery as sugary or milky[26].

Cord abnormalities:

While reporting MRI of spinal dysraphism following abnormali-ties in the cord and the spinal canal should be looked for:

a) Syrinx - The term syrinx encompasses the hydromyelia andsyringomyelia, which cannot be differentiated on imaging.Hydromyelia refers to distension of the central canal withependymal lining. Syringomyelia refers to the paracentralcavity not lined by ependyma. It appears linear T2 hyper-intense signal in the cord with signal paralleling CSF in allpulse sequences[27]. While describing syrinx we shouldtalk about the location of syrinx/holocord syrinx, the di-mension of the syrinx, expansion of the cord present/absentand the cause of the syrinx (particular cause in spinal dys-raphism). Contrast is not required because the presence ofany tumour can be inferred from T2 weighted images basedon findings like nodularity, septations, adjacent cord abnor-mality or apparent mass[28]. Presyrinx refers to reversiblemyelopathy appearing hyperintense on T2 and hypointenseon T1 sequences, but not paralleling CSF signal, unlike true


Figure 5: Lipomyelocele. Axial T2 weighted MR image (Fig.5A),Sagittal T1 weighted MR image (Fig.5B) and Axial schematic di-agram (Fig 5C) of lipomyelocele. The neural plate is covered byfat (F) and skin along its dorsal aspect. MRI images also showsthat placode–lipoma interface (arrow) lies within spinal canal.F = Fat. The double arrow in Fig. 5A represents subarachnoidspace.

Figure 6: Posterior meningoceles. Sagittal T2 weighted imagesshow herniation of Cerebrospinal fluid (CSF) through the poste-rior spinal defect without neural elements within the herniatedsac. The locations are suboccipital (Fig. 6A), Cervical (Fig. 6B)and lumbar regions (Fig. 6C) marked by (star). There is associ-ated syrinx in the cord (arrow) in Fig.6B.

Figure 7: Diastematomyelia type 1. Axial T2 weighted MRI (Fig.7A and 7C) and axial CT (Fig. 7B) show splitting of cord into two(short arrows) separated by rigid osseous septum (long arrow)which is characteristic for type 1 diastematomyelia.

Figure 8: Diastematomyelia type 2. Coronal (Fig 8A) and axial(Fig. 8B) T2-weighted MR images show splitting of cord into twohemicords (arrows) within single dural sac separated by non-rigid septum and is characteristic of type 2 diastematomyelia.

Figure 9: Dorsal dermal sinus. Axial (9A), sagittal T2 (9B) andSagittal T1 (9C) weighted images show presence of a linear tract(arrow) extending from the skin surface into the spinal canalupto the level of dura. There is associated syrinx in the cord(star).

Figure 10: Intramedullary dermoid. Axial T2 weighted MRimage (Fig 10A) shows presence of hyperintense lesion in thespinal canal (large arrow) with a hypointense solid nodular area(short arrow). Coronal STIR (Fig 10B) shows suppression ofhyperintense lesion (arrow) s/o fat. Coronal post contrast T1weighted image (Fig 10C) shows enhancement of the solid nodu-lar area within the lesion (short axis). Fat containing componentof the lesion appear suppressed (long arrow). Axial T1 weightedimage (Fig 10D) shows associated dorsal dermal sinus markedby arrow. Histopathology confirmed it to be dermoid.


syrinx. The presyrinx is a reversible process; follow upscans will show resolution[29].

b) Tethered cord refers to low lying conus medullaris heldto the lower position by a tethering cause (spinal dys-raphism) or tight filum terminale. Although the normalending of the cord with reduced elasticity of the filumterminale also give rise to neurological symptoms. It ispostulated that increased traction on the cord leads to hy-poxic changes causing neurological symptoms of tetheredcord called tethered cord syndrome[30,31]. To label thespinal cord as being the low ending, the conus should beat least seen below L2 vertebra[32,33]. While reportingtethered cord, points to mention are causative principleopen/closed spinal dysraphism (myelomeningocele, mye-locele, lipomyelomeningocele, diastematomyelia or dorsaldermal sinus), level of conus medullaris, the thickness offilum terminale and presence of other factors causing teth-ering like lipomas, epidermoid or dermoid. The prone scanis necessary only when the causative factor is not seen orwhen scarring is suspected to be the cause of tethering likein post-op open dysraphism[34].

c) Tight filum terminale – On MRI tight filum terminale ap-pears thick, short and measures more than 2 mm. It is usu-ally associated with a lipoma. Tight filum terminale mightappear positioned posteriorly and in close relation with theposterior dura especially on prone images. The distal endof the cord may appear stretched rather than curved. Thecauda equina nerve roots appear normal in location. Thesefindings are of equivocal diagnostic importance. Normalappearing filum with normal ending conus medullaris doesnot rule out tethered cord syndrome referred to as occulttight filum terminale. In such cases, symptoms are causeddue to reduced filum elasticity during movements causingtraction on the conus [34].

d) Diastematomyelia

e) Dorsal dermal sinus

f ) Limited dorsal myeloschichis (LDM) is a solid fibroneurotictract extending from the skin surface to the spinal cord.Main differences between the LDM and DDS are 1) LDM isa solid tract without lumen; hence chances of infection areless. DDS is an epithelial lined tract with lumen providingaccess to the external pathogen to neural tissues increasingchanges of spinal infection. 2) LDM is attached to the cordabove the level of conus medullaris. DDS extends fromthe skin surface to variable distance inward not necessar-ily terminating on the cord. 3) LDM tract contains densemesenchymal tissue hence causes dorsal tenting of the cordat the attachment site. DDS does not alter the shape of thecord. 4) LDM is not associated with an increased incidenceof associated tumours like dermoid or epidermois, unlikeDDS[35].

g) Meningocele manqué refers to abnormal tissue tetheringof the dura’s cord and does not extend beyond dura. It isthought to be a remnant of atretic meningocele[36].

h) The persistent terminal ventricle is seen as a small, ependy-mal lined cavity within the conus medullaris. Key imag-ing features include location immediately above the filum

Figure 11: Intradural lipoma. Axial T2 (Fig. 11A), and SagittalT1 (Fig. 11B) weighted MR images show linear extramedullaryintradural lesion (arrow) along the posterior aspect of lumbarspinal canal appearing hyperintense on both the sequences. Fatsuppression T1 sagittal (Fig 11C) image shows signal suppres-sion of intradural lesion confirming it to be lipoma. The upperand lower thick arrows on the sagittal images represent the up-per and lower limit of the intradural lipoma respectively. Thethin arrow points towards the fat and spinal cord is representedby letter “s”.

Figure 12: Filar lipoma. Axial T2 weighted MR image (Fig.12A)and Sagittal T1 weighted MR image (Fig.12B) shows hyperin-tense lesion along filum terminal (arrows) which shows sup-pression on coronal STIR image (Fig 8C). These features areconsistent with filar lipoma.

terminale and lack of contrast enhancement, which differ-entiate this entity from other cystic lesions of the conusmedullaris[13].

Vertebral segmentation anomalies [Figure 13]

Refer to the abnormal appearance of the vertebral bodies and/ortheir posterior elements due to problem in the fusion of theossification centres. Things to include in a report include the typeof anomaly, site/level of an anomaly, single/multiple, spinalcurve (normal, scoliosis, kyphosis, lordosis and kyphoscoliosis).In the presence of scoliosis, Cobb’s angle needs to be determined.The terminology used to describe vertebral anomalies [4,37] isgiven in Table No. 5.

Brain findings:

a) Any features of the Chiari malformation should be stated.

b) Any features of corpus callosal agenesis.

c) Hydrocephalus.

Ancillary findings:

Cutaneous stigmatas are crucial as they might be firstsign/indication of an underlying neurological problem during


Figure 13: Vertebral segmentation anomalies. Coronal T2weighted images show butterfly vertebra (arrow in Fig 13A),Hemivertebra (arrow in Fig. 13B). Wedge vertebra (arrow in Fig13C) and Sacral agenesis (Dashed circle in Fig 13D).

the first newborn examination. These could be divided intohigh, intermediate and low-risk markers. Although in the pres-ence of any of these stigmatas MRI spine should be thoroughlyscrutinized for abnormality. The high-risk stigmatas need moreattention.[3]

Others:

Renal abnormalities (like agenesis, horseshoe kidneys, crossedfused ectopia, etc), neurogenic bladder, anorectal malformationshould be mentioned in the report.

The findings of our study concurred with other studies donein the past. Among the total number of 100 patients enrolledin our study, 54 patients have undergone surgery in our insti-tution. On the correlation of our MRI findings with surgicaldata obtained from packs system, we found that all 54 patients’findings during surgery were correlating with the MRI findingsgiven preoperatively. This proves MRI to be highly accurate indiagnosing all the known spinal dysraphic anomalies.

Conclusion

A systematic approach while reporting a case of suspected spinaldysraphism is helpful in the classification of principle malfor-mation and to enumerate plethora of other associated anomalieslike Chiari malformation, syrinx, tethered cord, vertebral seg-mentation anomalies. Meticulous reporting of all the anomaliesis essential as they have important implication in the surgicalmanagement and prognostication of the patients. Template re-porting will help provide all the relevant information in orga-nized format without overlooking any findings. A close agree-ment was found between our MRI reports and surgical andhistopathological reports in all operated cases.

REPORTING TEMPLATE:

1. Age and sex – Months/years and M/F

2. Clinical indications:

I. Skin defect with exposed placode or swelling at theback with intact skin +/-

I I. Neurological +/-

I I I. Urological +/-

IV. Orthopaedic +/-

V. Cutaneous stigmata +/- (mention if any)

3. MRI sequences: Sagittal/coronal/axial T1/T2 sequences,Non fat saturation/Contrast/Diffusion

4. Location of the lesion – (Cervical) (Thoracic) (Lum-bar)(Lumbosacral)

5. Description of the principle or main malformation

Skin defect +/-

Relation of neural placode with the skin defect

Subcutaneous mass +/-

Contents of subcutaneous mass (fat, fluid, neural tissue)

Describe the principle malformation

6. Spinal cord abnormalities on MRI

a) Syrinx: Location ExtentExpansion of cord +/-Nodularity+/-Septation +/-Presyrinx +/-

b) Tethered cord: Level of conus medullarisAssociated mass:Lipomas +/- Epidermoid +/- Dermoid +/-

c) Tight filum terminale:Thickness of filum terminaleAssociated lipomasProne scan if everything appears normal.

d) Diastematomyelia: Location of the splitLength of cord involvedOsseous /fibrous spur, site of the spur and its attach-ments.

e) Dorsal dermal sinus: LocationThe extent of the tractSite of termination(subcutaneous, extradural, sub-arachnoid space, spinal cord, conus medullaris,filum terminale or the nerve roots Associated der-moid/epidermoid Meningitis/abscess

f ) LDM LocationExtent of the tractAssociated lesion

g) Meningocele manqué:+/-LocationExtent of the tractAssociated lesion

h) Intradural lipomas

7. Vertebral segmentation anomalies on MRI:

a) Failure of formation:Asomia +/-Wedge vertebrae +/-Hemivertebrae +/-Butterfly vertebrae +/-Coronal cleft +/-Pedicular anomalies+/-Spina bifida +/-

b) Disorders of segmentation:

c) Combined


d) Segmental spinal dysgenesis – describe the anomaly.

e) Caudal agenesis: Type I / II

8. Curvature abnormalities of the spine:

Scoliosis:+/-

Kyphosis:+/-

Kyphoscoliosis. +/-

Cobbs angle +/-

9. Brain anomalies:

Arnold Chiari malformation +/-

Hydrocephalus +/- Corpus callosal agenesis +/-

10. Other findings:

Renal tract and other anomalies

Neurogenic bladder +/-

HDUN +/- Anorectal malformation +/-

11. Cutaneous stigmatas detectable on MRI

Dorsal dermal sinus +/-

Dermoid +/-

Ethical Approval

The study was commenced following institutional ethical clear-ance. The informed consent waived off by the ethical committeddue to the retrospective nature of the study.

Funding

There is no funding

Conflict of interest

The authors declared that this project was done independentlywithout any conflict of interest.

Author’s Contribution

Dr Nilkanth Pal, Dr Ambika Sumeet Juwarkar, Dr Zarina Assisand Dr Sanjay Viswamitra have given a substantial contributionto the conception, design of the work, the acquisition and inter-pretation of data. Each author has helped in drafting the workor revising critically important intellectual content. All authorshave read and approved the final version of the manuscript.

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