Spectrum of intracranial incidental findings on pediatric brain magnetic resonance imaging: What clinician should know?

Table 1 Summarizes the reports of intracranial incidental findings in children on brain magnetic resonance imaging[5-22]

Ref.	Country	Study objective /conclusion
Yilmaz et al[5]	Turkey	To evaluate clinical significance of MRI abnormality in children with headache/
		Despite the high rate of IFs, the yield is non-contributory to diagnosis and therapy
Bayram et al[6]	Turkey	To describe the prevalence of WML detected on MRI in children with headaches/ Non-specific WML may be seen in children with headache. In the absence of benefit, repeated MRI studies are unwarranted. It should be tailored according to clinical course
Graf et al[7]	United States	Studied the frequency and consequences of IFs on non-acute pediatric headache/
		The frequency and types of all IFs were generally comparable to previous studies
Schwedt et al[8]	United States	To study the frequency of “benign” abnormalities in children with headache, compare it with the frequency of MRI findings that dictate a change in patient management/
		About 20% children with headache have benign findings that do not result in a change in management which rarely occurred in 1.2% of children in this study
Koirala[9]	Nepal	To evaluate the yield of MRI findings in patients with seizure/
		The majority of abnormalities on MRI included hippocampal sclerosis and T2 hyperintensity
Kalnin et al[10]	United States	To characterize IFs association with seizure onset and to standardize a classification system/
		The MRI and a standardized scoring system demonstrated a higher rate of IFs than previously reported. MRI parameters need to expand the definition of significant IFs
Gupta et al[11]	United States	To test the hypothesis that children with developmental delay are more likely to have incidental findings than are the children with normal development status/
		Authors reported a higher prevalence of IFs in children with developmental delay as compared with those with normal development status
Seki et al[12]	Japan	To report prevalence of IFs in healthy children and to suggest an ethical and practical management protocol/
		The prevalence of IFs was high but those requiring further MRI was low. Evaluating equivocal findings was the most difficult part of IFs management
Gupta et al[13]	United States	To elucidate the prevalence of incidental findings in a general pediatric neurology practice/
		Authors reported a high prevalence of and a low rate of referrals in comparison to previous studies. This study may help guide management decisions and discussions
Potchen et al[14]	Malawi	To collect normative magnetic resonance imaging data for clinical and research applications/
		Incidental brain magnetic resonance abnormalities are common in Malawian children
Kim et al[15]	United States	To elucidate the prevalence of incidental findings in a healthy pediatric population/
		Frequency of important IFs was not high. But, awareness of neurologic status, the presence and variety of IFs are of vital importance for research and welfare of the child
	Incidental findings in pediatric specialty clinic other than neurology
Oh et al[16]	South Korea	To investigated the clinical characteristics of children in whom Rathke’s cleft cysts were incidentally discovered and the treatment response with endocrinopathy/
		Rathke’s cleft cysts less than 20 mm expressing cystic intensity can be treated medically
Rachmiel et al[17]	Canada	To assess IFs in children with congenital hypothyroidism compared to 38 healthy controls/
		Both groups had a similar incidence of structural abnormalities. There was no association between those findings and neurocognitive function
Whitehead et al[18]	United States	The prevalence of pineal cysts in children who have had high-resolution 3T brain MRI/
		Characteristic-appearing pineal cysts are benign findings. In lack of no referable comprehensive symptoms, no follow-up is required
Mogensen et al[19]	Denmark	To evaluate the outcome of brain MRI in girls referred with early signs of puberty/
		Girls with central precocious puberty should have a brain MRI
Perret et al[20]	Switzerland	The prevalence and management options of incidentally found mass lesions at pediatric clinic/
		A subgroup of lesions such as tectal glioma and dysembryoplastic neuroepithelial tumor can be monitored conservatively
Jordan et al[21]	United States	The prevalence of incidental findings on brain MRI in children with sickle cell disease/
		IFs were present in 6.6% patients and a potentially serious or urgent finding was 0.6%

All except four studies: Potchen et al[14], 2013, Rachmiel et al[17], 2013, Koirala[9], 2011, and Seki et al[12], 2010, were retrospective. The retrospective study by Jordan et al[21], 2010 was carried out as a clinical trial for sickle cell disease. Itoh et al[22], 1994, investigated the evolution of high-signal–intensity abnormality on T2-weighted MR images[22] which are the expected findings thus it was excluded from this review. WML: White matter lesions; IFs: Incidental findings; MRI: Magnetic resonance imaging.

Table 2 Clinical demography of intracranial incidental findings on pediatric brain magnetic resonance imaging evaluated at general neurology clinic and at research center[5-15]

Ref.	Clinical demographics					Girls n (%) with MRI
	Study- setting	Reason for MRI	No. ofsubject	No. ofMRI (%)	Mean age(range) year
Yilmaz et al[5]	Pediatric neurology	Head pain	449	288 (64)1	11.2 (NA)	189 (58)
Bayram et al[6]			941	527 (61)2	12.1 (4-16)	NA
Graf et al[7]			400	91 (23)2	10.8 (3-18)	NA
Schwedt et al[8]			681	218 (32)2	12.1 (2-18)3	126 (52)
Koirala[9]	Pediatric and adult neurology	Seizure	36c	36 (100)3	NA (1-16)	NA
Kalnin et al[10]	Radiology		349	281 (81)	9.7 (6-14)	143 (51)
Gupta et al[11]	Pediatric neurology	Developmental delay	2185	771 (35)	7.6 (NA )	433 (56)
Gupta et al[13]		General	1618	666 (41)	9.8 (0-21)	280 (42)
Seki et al[12]	Research Institute	Healthy children	395	89 (25)1	NA (5-8)	53 (44)
Kim et al[15]	Radiology		225	198 (88)1	11.2 (1 mo-18)	126 (56)
	Research
Potchen et al[14]		Community-based	102	68 (71)1	12.1 (9-14)	54 (55)

¹The MRI revealing extracranial incidental findings were excluded;

²Children with computerized tomography of the brain were excluded;

³Only pediatric patients are presented in Table. MRI: Magnetic resonance imaging; NA: Not available.

Table 3 Clinical demography of children with intracranial incidental findings on pediatric brain magnetic resonance imaging studies at pediatric specialty clinic other than neurology[16-21]

Ref.	Study-setting	Reason for MRI	No. of subject	No. of MRI (%)	Clinical demographics
					Mean age(range) year	Girls n (%) with MRI
Oh et al[16]	Endocrinology	Rathke’s cleft cysts	341	26 (76)	NA (4-18)	17 (65)
Rachmiel et al[17]	Endocrinology	Congenital hypothyroidism	682	30 (100)	12.5 (10-15)	16 (55)
Whitehead et al[18]	Radiology	Pineal cyst	100	100 (100)	6.8 (1 mo-17)	52 (52)
Mogensen et al[19]	Endocrinology	Early puberty	229	207 (100)3	NA (6-9)	207 (100)
Perret et al[20]	Oncology	Primary brain tumor4	335	335 (100)	7.6 (0-18)	132 (39)
Jordan et al[21]	Neurology research	Sickle cell disease	953	953 (100)	9.2 (5-15)	460 (48)

¹76% of patient with Rathke’s cleft cysts were discovered during evaluations for endocrine disorders;

²This includes 38 healthy boys 11.7 ± 1.7 years;

³22 (11%) patients who had computerized tomography of the brain due to contraindication of MRI are not included in this table;

⁴Central nervous system tumors were identified incidentally. MRI: Magnetic resonance imaging; NA: Not available.

Table 4 Lists three most commonly reported intracranial incidental findings on brain magnetic resonance in various pediatric-settings[5-19]

Ref.	Three most common intracranial IFs, n (%)	Comment or serious finding
Yilmaz et al[5]	White-matter hyperintensity 14 (4.3) Old infarcts 4 (1.2), and CM I 3 (0.9)	2 (0.6%) malignant tumor and 1 hydrocephalus, 0.3% IFs were relevant to headache
Bayram et al[6]	Supratentorial non-specific WMC 23 (4.4)	All patients with IFs had normal development and no seizures or head trauma
Graf et al[7]	CM I 6 (15), arachnid cysts 6 (15), brain stem parenchymal abnormality, 4 (10)	Brain stem IFs included Dandy-Walker variant, cerebellar calcification, and tectal plate hyperintensity
Schwedt et al[8]	CM I 11 (4.6), nonspecific white matter abnormalities 7 (2.9), venous angiomas and arachnoid cyst each 5 (2.5)	Discovery of 4 tumors, 4 old infarcts, 3 CM I, and 2 moyamoya required a change in management
Koirala[9]	Hippocampal sclerosis, T2 hyperintense foci in various distributions, both 4 (21) each, cortical atrophy 3 (16)	Study focus was IFs in patient with seizure. The lesions were better detected by MRI than computerized tomography
Kalnin et al[10]	Ventricular enlargement 143 (51), leukomalacia/gliosis 64 (23), heterotopias and cortical dysplasia 33 (12)	Temporal lobe lesions were detected 15%, a higher frequency than in previous studies
Gupta et al[11]	Variant signal intensity 30 (18), WMC changes 23 (13), and PVL, 10 (6)	IFs were reported in children with developmental delay as to those with normal development status
Seki et al[12]	Cavum septi pellucid 6 (15) and Pineal cyst 2 (5 ), Enlarged perivascular spaces 1 (2.5)	Focus of the study was reporting of extracranial IFs in healthy children
Gupta et al[13]	CM I and cerebellar ectopia, 16 (3.5), Arachnoid cysts, 12 (1.8)	White matter changes were the most common IFs classified under normal-variants
Potchen et al[14]	PVW matter changes/gliosis 6 (6), mild diffuse atrophy 4 (4), and Empty sella 3 (3)	Incidental findings were unassociated with age, sex, antenatal problems, or febrile seizures
Kim et al[15]	Focal white matter lesion 3 (1.3), arachnoid cyst, frontal venous angioma, and mega cisterna magna, all three 2 (0.9) each	IFs were detected on 225 conventional research in a cohort of neurologically healthy children
IFs in pediatric specialty clinics other than neurology
Oh et al[16]	Low signal intensities on T1-WI and high signal intensities on T2-WI 26 (73)	Incidence of hypointensity on T1-WI was higher in patients with Rathke’s cleft cysts
Rachmiel et al[17]	Prominent VR perivascular spaces, cerebellar ectopia, and abnormalities in sella region all 3 (7.9) each	The comparative study found no IFs association with clinical and cognitive abnormalities
Mogensen et al[19]	Arachnoid cysts 5 (9.2), of which one patient had hydrocephalus	Incidental findings were unrelated to early puberty

The study by Whitehead et al[18], 2013, which is not listed in table, because this study was limited to prevalence of pineal cysts in children, who have undergone high-resolution 3-T MRI. CM I: Chiari malformation I; WMC: White matter changes; VR: Virchow-Robin; PVL: Periventricular malacia; PVW: Periventricular white matter changes; IFs: Incidental findings; MRI: Magnetic resonance imaging.

Table 5 Summarizes incidentally found “serious lesions” on pediatric brain magnetic resonance imaging

Ref.	The context in which brain MRI was ordered	Worsening course		Outcome/comment
		Known	Potential
Yilmaz et al[5]	Children mean age 11.2 yr presented for headache evaluation	Malignant brain tumor and hydrocephalus	Chiari I malformation I; Relevant to headache	Tissue type of tumor in study was unspecified
Schwedt et al[8]	Children mean age 12.1 yr presented for headache evaluation	Tumors, moyamoya disease, and demyelinating disease	Arteriovenous malformation and intracerebral hemorrhage	Study focus was “benign” imaging abnormalities, no further information for serious lesion other than pineal tumor was available
Kalnin et al[10]	Children mean age 9.7 yr presented for the first onset seizure	None	Temporal lobe lesions	Various Epileptic abnormalities1 have been associated with pediatric brain MRI
Potchen et al[14]	Community-based children mean age 12.1 yr	Granulomas with gliosis	Empty sella and vermian atrophy	Calcified granulomas caused by neurocysticercosis or tuberculosis occurs in the endemic part of the world
Mogensen et al[19]	All girls, mean age unavailable, presented for early puberty evaluation to endocrine clinic	Pontine and pineal tumor, and hypothalamic pilocytic astrocytoma	Hydrocephalus, cortical dysplasia, and chiari II malformation	A high frequency a pathological brain findings occurred in 6-8 yr old girls with precocious puberty
2Perret et al[20]	Incidentally found mass lesions management in children mean age 7.6 yr in oncology	Low-grade glioma, craniopharyngioma, ependymoma, and CPP	Medulloblastoma and fibrillary astrocytoma	Dysembryoplastic neuroepithelial tumor and tectal glioma can be monitored conservatively
Jordan, et al[21]	Children mean age 9.2 yr with sickle cell disease in neurology research	Chiari I malformation with large spinal cord syrinx3	Possible tectal glioma, Possible tumor vs dysplasia	Amongst 6.6% incidental findings identified, 0.6% children with sickle cell disease had potentially serious or urgent finding

¹Various epileptic abnormalities includes leukomalacia/gliosis, encephalomalacia, any gray matter lesion, mass lesion, hemorrhage, vascular lesion, hippocampal abnormality, ventricular enlargement > 1.5 cm, or prominence of extra-axial fluid spaces > 1.0 cm[31];

²Of 335 newly diagnosed central nervous system tumors (CNS), 19 (5.7%) children’s CNS tumors were identified incidentally;

³Of note: Chiari I malformation with a small cervical spinal cord syrinx in asymptomatic patients is not uncommon on pediatric brain MRI. CPP: Choroid plexus papilloma; MRI: Magnetic resonance imaging.

Table 6 A proposal for a common clinical profile of intracranial incidental findings on pediatric brain magnetic resonance imaging

	Clinical implication
Discovery of the unexpected incidental findings	Revealing during investigation enhances the patients or parents anxiety. The evidence-based knowledge will provide an additional confidence for the practicing physicians
Type of the incidental findings	Varieties of white matter changes are reported. However, these usually do not initiate a neurologic consultation. Chiari type I malformation, arachnoid cyst, and pineal cyst, all continued to be a common source of concern for some physicians
Distribution of incidental findings	Attention to the distribution of findings is a useful tool in deciding the clinical importance of such findings. A midline lesion particularly in the posterior fossa and hippocampal location is likely to have a serious clinical implication
The clinical context in which MRI was performed	This is probably the single most important step in understating the clinical implication of incidental findings (Table 6). This is particularly important when the child was referred to neurology after revealing the incidental finding on brain MRI

MRI: Magnetic resonance imaging.

Table 7 Summarizes the neurosurgical intervention and their outcome in children with incidentally discovered serious lesions

Ref.	Incidentally found serious findings	No. ofpatients	Surgical procedure performed	Outcome
Schwedt et al[8]	Chiari type I malformation	3	Surgical decompression	Headache relieved in 2 patients after surgery
Jordan et al[21]	Chiari I malformation with spinal cord syrinx	2	Surgical decompression	Neurologic stable
Perret et al[20]	Pilocystic astrocytoma	2	Primary subtotal resection	Stable disease
	Craniopharyngioma	1	Primary total resection	Complete remission
	Anaplastic ependymoma	1	Primary total resection, radio-chemotherapy	Complete remission
	Choroid plexus papilloma	1	Primary total resection	Complete remission
	Medulloblastoma	1	Delayed subtotal resection, radio-chemotherapy	Neurologic stable
	Fibrillary astrocytoma	1	Delayed total resection	Complete remission
	Mature teratoma	1	Delayed subtotal resection	Neurologic stable
	Desmoplastic ganglioglioma	1	Primary total resection	Complete remission
Mogensen et al[19]	Pilocytic astrocytoma	1	Hypophysectomy	Patients developed pan hypopituitarism after surgery
Yilmaz et al[5]	Medulloblastoma	1	Urgent surgery for space occupying lesion	Headache relieved after surgery

Incidental findings; Chiari I malformation studied by Seki et al[12], 2010 and temporal arachnoid cyst with mass effect and cerebellar venous malformation studied by Gupta et al[13], 2008 all three were referred to neurosurgery, but no information regarding outcomes were available.