View of Mini Literature Review on the Classification of Intracranial Calcification and the Usefulness of Cone Beam Computed Tomography

PakHeartJ2023:56(03)ISSN:0048-2706E-ISSN:2227-9199881http://www.pkheartjournal.comMini Literature Review on the Classification of Intracranial Calcification and the Usefulness of Cone Beam Computed TomographyTawfiq Y T Zyoud1, Abubakar Kabeer2,Mohamad Syafeeq Faeez Md Noh1, Suzana Binti Ab Hamid1, Rozi Mahmud1, Saiful Nizam Abdul Rashid3, Subapriya Suppiah1,4,Rajeev Shamsuddin Perisamy5,Anas Tharek1, Ezamin Abdul Rahim1*1Department of Imaging, Faculty of Medicine and Health Sciences, UniversitiPutra Malaysia43400 Serdang Selangor2Department of Human Anatomy, College of Medical Sciences, Federal University Lafia, P.M.B 146 Akunza, Lafia, Nasarawa State, Nigeria3Ramsay Sime Darby Parkcity Medical Centre, 52200 Kuala Lumpur.4Centre for Diagnostic Nuclear Imaging Universiti Putra Malaysia 43400 Serdang Selangor5Kulliyyah of Medicine, International Islamic University Malaysia, MalaysiaAbstractIntracranial calcification has numerous radiographic and clinical presentations; therefore, classifications and the age of the patients are very important in the detection and diagnosis of the calcifications. Interestingly, cone beam computedtomography (CBCT) provides a useful imaging technique that is very crucial in the neuro-intervention regime; although, CBCT image is faced with some drawbacks such as poor soft tissue contrast, artifacts, and noise, however, these drawbacks are taken careof with the advent of improved techniques and software algorithms that improves signal-to-noise ratio contrast.Keywords: CBCT, calcification, lesion, intracranial calcification1.0IntroductionPrecision in radiological diagnosis plays a vital role in patients' detection andtreatment planning (Evlice, 2017). Cone beam computed tomography (CBCT) is a renownedradiographic imaging techniquethat producesa three-dimensional (3D) image of hard tissues (Kumar et al., 2015; Mutalik & Tadinada, 2017; Spagnuolo, 2022)and has proven to be an important imaging technique that is vital in the neuro-intervention procedure (Dong et al., 2021; Jain et al., 2019).Further, CB CT’sinvention aims to offsetsome of the limitations in conventional CT scanning devicessuch as improvement in high imaging resolution with excellent contrast visualization invessels, softtissues, and bone(Dong et al., 2021; Evlice, 2017).Theadvent of sensors with high anatomical display fields makes the brain an important anatomical region readily for visualization using CBCT scans(Bayrak et al., 2019; Nguyen & Enciso, 2012).CBCT provides clear images with high-contrast structures and is an imaging technique suitable for craniofacial regions, that is extremely useful in the evaluation of bone and other hard tissues. Moreover, CBCT technological ingress in clinical practice creates several possible advantages for craniofacial imaging when compared to conventional CT (Scarfe et al., 2006). Putting into account that CBCT has made speedy breakthroughs in the recent field of radiology, however, it is associated with some limitations which may be attributed to its projection geometry, contrast resolution, and detector sensitivity, further, CBCT image clarity is greatly affected by noise, poor soft tissue contrast, and artifacts (Venkatesh & Elleru, 2017; Scarfe et al., 2006). Nevertheless, efforts are being tilted towards developing software algorithms and techniques to improve contrast and signal-to-noise ratio (Scarfe et al., 2006).Brain and intracranial calcification are common findings in radiographic techniquesranging from benign physiological calcification to severe pathological disorders that could lead todeath (Daghighi et al., 2007; Grech et al., 2012).Intracranial calcifications result fromthe accumulationof calcium and iron in the blood vessels of different brain structures (Daghighi et al., 2007; Guedes et al., 2020), hence intracranial calcification is termed the calcification within the brain parenchyma or its vasculature (Al-Zaghal et al., 2019; Daghman & Bennour, 2020).Choroid plexus and pineal region calcifications are common intracranial calcification known to be present histologically from fetal life to adulthood (Al-Zaghal et al., 2019; Saade et al., 2020).Conversely, it is a very difficult task to determinethe specific cause ofphysiologicallycategorizedintracranial calcification in patients due to age and other causes of calcification, however, understanding the anatomical location and morphology, dimension, distribution of the calcifications as well as age groupand clinicalhistory of the patient serves as important findingsthat can facilitate the differential diagnosis(Chattopadhyay et al., 2020; Guedes et al., 2020).

PakHeartJ2023:56(03)ISSN:0048-2706E-ISSN:2227-9199882http://www.pkheartjournal.comIt is worthnotingthat due to the advent of some technological breakthroughsin recent decades, imaging modalitiesand methodshave improved both in specificity and sensitivity of their assessment which assists in the diagnosis andreduces the possibility ofprecisionerrors(Evlice, 2017; Guedes et al., 2020; Nguyen & Enciso, 2012).Thismini-reviewis aiming athighlightingthe importance of cone beam computed tomography and classifyingintracranial calcifications.2.0Classification of IntracranialCalcificationIntracranial calcifications are commonly foundin non-contrast computedtomography scans in both adult and pediatric groups(Saade et al., 2020). Calcification of soft tissues in the maxillofacial region is a rare phenomenon that correspondsto findings in radiographic routine examinations such as panoramic radiographs (Altındağ et al., 2017). However, the calcification of soft tissues in the region of the head and neck can be categorized as physiologic or pathologic mineralization(Bayrak et al., 2019). Although, most of the structures in the head and neck are relatively close to each other making the localization and identification of these calcifications difficult(Altındağ et al., 2017; Price et al., 2012).2.1Physiological orAge-Related CalcificationPhysiological or age-related calcification is associated with radiological findings in adults and elderly patients which can be found in the pineal gland, globus pallidus, choroid plexus, dura mater, habenula, petroclinoid ligament, tentorium,and cerebral sickle(Guedes et al., 2020). Further, pineal gland calcification is mostly seen in individuals more than 10 years of age with high prevalence, thus, globus pallidus calcification is seen in individuals more than 40 yearsof age(Guedes et al., 2020; Nguyen & Enciso, 2012). The deposition of calcium in the brain parenchymain the absence of any neurological or underlying pathologies is termed idiopathic calcification(Al-Zaghal et al., 2019), however, normal physiologic aging and neurodegenerative processes arethought to be related to idiopathic intracranial calcification (Daghighi et al., 2007).2.2Pathological Calcification2.2.1Metabolic and Endocrine DisorderCalcificationDisruption of calcium homeostasis could lead to brain calcification, these disorders include hyperthyroidism, hyperparathyroidism, and hyperparathyroidism, moreover, these diseases have overlapping radiological signs which make them difficult to differentiate visuallydue to their characterized bilateral, symmetric calcium deposition in different brain regions (Guedes et al., 2020; Saade et al., 2020). 2.2.2VascularCalcificationVascular calcification (VC) is the pathological deposition of minerals in the vascular systemwhich is attributed to degenerative disease affecting the wall of blood vessels(Wu et al., 2016).It could be due to the consequences of atherosclerosis,chronickidney disease(CKD), diabetes,inflammatory disease,or aging with an increased risk of cardiovascular disease and mortality (Hénaut et al., 2015; Jono et al., 2006; Wu et al., 2016). Vascular calcification is age and gender-dependent with 90% of men and 67% of women older than the age of 70 years(Mohan et al., 2016). Further, VC is clinically believedto be a result of the passive precipitation of minerals, however current clinical evidence established that VC results from an active and highly regulated cellular process similar to bone formation(Hénaut et al., 2015).Electron beam computed tomography (EBCT) examinations reveal that vascular calcification is very common among dialysis patientswith coronary calcification scores of 2-5 times higher than non-CKD patients (Jono et al., 2006).2.2.3InfectionsDisease CalcificationCryptococcus, cysticercosis, and tuberculosis are regarded as acquired intracranial infections naturally related to intracranial calcification, although calcification resulting from brain abscesses is particularly rare (Kim et al., 2013).Noteworthy, a brain abscess begins as a focal area of a localized area of cerebritis with pus collection surrounded by a vascular capsulewhich develops as a result of response to parenchymal infections due to bacterial infection(Gortvai et al., 1987; Rath et al., 2012).2.2.4Neoplastic LesionsCalcificationIn the identification and evaluation of brain neoplasm, brain calcification plays a vital role hence, thepresence or absence of calcificationsalong withthe location of the tumor and the patient’s age assist in routine radiological identification of neoplasm (Saade et al., 2020). Neoplasm is classified into intra-axial (astrocytoma, oligodendroglioma, ganglioma, medulloblastoma,and metastatic lesions), extra-axial (meningioma, craniopharyngioma, pineal tumor, and germ cell tumor) and intraventricular which are commonly ependymomas, choroid plexus tumors and neurocytoma (Dinizio et al., 2016; Grech et al., 2012; Saade et al., 2020). 2.2.5Non-neoplastic Expansive LesionsCalcificationLesions such as epidermoid cysts, dermoid cysts, colloid cysts, and meningiomatosis are classified as non-neoplastic lesions that have an expansive character that can sometimes resultincalcification (Guedes et al., 2020; Osborn & Preece, 2006).

PakHeartJ2023:56(03)ISSN:0048-2706E-ISSN:2227-9199883http://www.pkheartjournal.com2.2.6Neurocutaneous LesionsCalcificationDiseases that share signsof both cutaneous and neurological disordersoften present with a distinct characteristic of calcifications(Guedes et al., 2020). These diseases include tuberous sclerosis, Gorlin-Goltz syndrome, Sturge-Weber syndrome,and neurofibromatosis (type I and II)which are definitive in diagnosis (Osborn & Preece, 2006; Umeoka et al., 2008).Figure 1: Schematic representation of a classification of calcification.Clinical Significance of IntracranialCalcification Intracranial calcification is an important biomarker in identifyingatherosclerosis and understanding the severity of intracranial vascular disease (Wu et al., 2016).The leading cause of ischemic stroke nationwide is an intracranial atherosclerotic disease, accountingfor about 30-50% of Asians and 10% of Caucasians (Yang et al., 2021).In 2007, Cheng et al in their cross-sectional study reported an increasein the incidence of intracranial arterial calcification (IAC)among Chinese ischemic stroke patients(Chen et al., 2007), although, other studies indicated that IAC is not an independent predictor in recurrent stroke among Chinese patientsand shows no significant correlation between IAC and post-stroke mortality(Li et al., 2023; Yang et al., 2021).Interestingly, IAC is viewed as an incidental finding on some important imaging modalities on the brain such as CT and CBCT scansamong the majority of the population,even though most ofthe calcification isseen as not a threat,but others can be associated with seriousclinical consequences(Bartstra et al., 2020; van der Toorn et al., 2019).Noteworthy, calcification has been restricted to arteries in population-based research associated with cardiovascular risk factors such as diabetics, hypertension,and smokingplaya vital role in the manifestation of calcification in the aortic arch, coronary artery, external and internal carotid artery (van der Toorn et al., 2019).