Imaging Spectrum of Calvarial Abnormalities

Imaging approach to pediatric calvarial bulges

Palpable calvarial lesions in children may require multi-modality imaging for adequate characterization due to non-specific clinical features. Causative lesions range from benign incidental lesions to highly aggressive pathologies. While tissue sampling may be required for some lesions, others have a typical imaging appearance, and an informed imaging approach facilitates diagnosis. This review illustrates imaging findings of common and clinically important focal pediatric calvarial bulges to aid the radiologist in narrowing the differential diagnosis and directing appropriate referral. We focus on birth-related lesions, congenital abnormalities, and modeling disturbances (i.e., those that produce a change in calvarial contour early in development), normal variants, and neoplastic lesions with their mimics.

Pediatric Cranial Vault Pathology

A wide variety of diagnoses can be approached with a common framework for diagnosis, extirpation, and reconstruction of pediatric cranial vault pathologies. Durability of reconstruction is critical for the range of pediatric patients from infancy to adolescence. Rigid reconstruction, preferably with autologous tissue when possible, promotes brain protection and satisfactory aesthetic outcome. Careful planning can allow for immediate definitive reconstruction of defects without need for further surgical intervention.

Ultrasound as a standalone tool for the management of pediatric calvarial dermoid cysts

PURPOSE

Calvarial dermoid and epidermoid cysts are benign lesions common in pediatric neurosurgery. Diagnosis is primarily clinical, with frequent but inconsistent use of imaging. Dermoids have been shown to possess distinct sonographic features, but ultrasound (US) remains underutilized in their management. The purpose of this study is to investigate the independent reliability of US in managing pediatric calvarial dermoids and distinguishing them from other calvarial lesions.

METHODS

A retrospective review of consecutive patients ≤ 21 years of age with surgically resected calvarial masses between 2017-2024 was performed. Demographic, clinical, and imaging data were analyzed. Pearson chi-squared tests were used for comparison of categorical variables and a binomial linear model was generated controlling for age, lesion tenderness, growth, and suture location.

RESULTS

Fifty-nine patients with 61 lesions (31 in females; median age 13 months) were included. Dermoids were more common in younger patients (median age 12 months), along suture lines, and were less likely to present with tenderness (p < 0.001) or rapid growth (p = 0.003). Ultrasound was used in 83% of cases and was the sole imaging modality in 33%. On multivariate analysis, suture location was a significant positive predictor of a dermoid diagnosis (OR = 8.08, 95% CI = 1.67-44.18), while rapid growth was a significant negative predictor (OR = 0.08, 95% CI = 0.003-0.80).

CONCLUSION

Ultrasound presents a sensitive and reliable method for the evaluation of most pediatric calvarial lesions, especially dermoid cysts, and warrants being part of standard workup. With appropriate patient selection, US obviates the need for additional imaging in pediatric patients.

Prognostic value of visual IMPeTUs criteria and metabolic tumor burden at baseline [18F]FDG PET/CT in patients with newly diagnosed multiple myeloma

BACKGROUND

2-[18F]fluoro-2-deoxy-D-glucose ([18F]FDG) positron emission tomography combined with low-dose computed tomography (PET/CT) can be used at diagnosis to identify myeloma-defining events and also provides prognostic factors. The aim of this study was to assess the prognostic significance of baseline [18F]FDG PET/CT visual IMPeTUs (Italian myeloma criteria for PET Use)-based parameters and/or total metabolic tumor volume (TMTV) in a single-center population of patients with newly diagnosed multiple myeloma (NDMM) eligible for transplantation.

METHODS

Patients with MM who underwent a baseline [18F]FDG PET/CT were retrospectively selected from a large internal database of the University Hospital of Liege (Liege, Belgium). Initially, all PET/CT images were visually analyzed using IMPeTUs criteria, followed by delineation of TMTV using a semi-automatic lesion delineation workflow, including [18F]FDG-positive MM focal lesions (FL) with an absolute SUV threshold set at 4.0. In a first step, to ensure PET/CT scans accurate reporting, the agreement between two nuclear medicine physicians with distinct experience was assessed. In the second step, univariable and multivariable analyses were conducted to determine the prognostic significance of [18F]FDG PET/CT parameters on progression free survival (PFS) and overall survival (OS), respectively.

RESULTS

A total of 40 patients with NDMM were included in the study. The observers agreement in the analysis [18F]FDG PET/CT images was substantial for the presence of spine FL, extra spine FL, at least one fracture and paramedullary disease (Cohen's kappa 0.79, 0.87, 0.75 and 0.64, respectively). For the presence of skull FL and extramedullary disease the agreement was moderate (Cohen's kappa 0.56 and 0.53, respectively). Among [18F]FDG PET/CT parameters, a high number of delineated volumes of interest (VOI) using the SUV4.0 threshold was the only independent prognostic factor associated with PFS [HR (95% CI): 1.03 (1.004-1.05), P = 0.019] while a high number of FL (n > 10; F group 4) was the only independent prognostic factor associated with OS [HR (95% CI): 19.10 (1.90-191.95), P = 0.01].

CONCLUSION

Our work confirms the reproducibility IMPeTUs criteria. Furthermore, it demonstrates that a high number of FL (n > 10; IMPeTUs F group 4), reflecting a high [18F]FDG-avid tumor burden, is an independent prognostic factor for OS. The prognostic value of the TMTV delineated using a SUV4.0 threshold was not significant. Nevertheless, the count of delineated [18F]FDG-avid lesions VOI using a SUV4.0 threshold was an independent prognostic factor for PFS.

Imaging of congenital anomalies and defects of the skull base and calvarium

Congenital anomalies and defects of the skull base and calvarium encompass a broad and complex spectrum of pathologies. The clinical presentation is highly variable, and these anomalies may be discovered incidentally in asymptomatic individuals. Radiological assessment plays a pivotal role in precisely characterizing these abnormalities, facilitating the diagnostic process, and assisting in any preoperative preparation.

Radiographic Orofacial Findings of Systemic Diseases

This article discusses the orofacial clinicoradiographic features of systemic diseases that manifest in the orofacial region. The systemic diseases discussed are grouped into the following: autoimmune diseases, endocrine diseases, bone diseases, hematologic diseases, syndromes, and malignancies. The radiographic manifestation ranges from radiolucent bony destruction, increased bone density, calcification, thinning of cortical plate, loss of trabeculation, missing teeth, and supernumerary teeth. It is imperative for clinicians to be cognizant of these findings, as they may be the first manifestation of these systemic diseases.

Pediatric focal calvarial lesions: an illustrated review

Focal skull lesions in children can be diagnostically challenging with a wide variety of potential etiologies. Understanding the diverse pathologies and recognizing their associated clinical and imaging characteristics is crucial for accurate diagnosis and appropriate treatment planning. We review pertinent anatomy of the scalp and calvarium and review different pathologies that can present with focal skull lesions in pediatric patients. These include neoplastic, non-neoplastic tumor-like, congenital, post traumatic, and vascular-associated etiologies. We review the key clinical and imaging features associated with these pathologies and present teaching points to help make the correct diagnosis. It is important for radiologists to be aware of the common and rare etiologies of skull lesions as well as the clinical and imaging characteristics which can be used to develop an accurate differential to ensure a timely diagnosis and initiate appropriate management.

Prevalence of intra-osseous veins and venous lakes in the posterior skull base on 3T MRI

BACKGROUND

Intra-osseous vessels are normal anatomic structures in the calvarium and skull base. On imaging, these structures-particularly venous lakes-can mimic pathologic abnormalities. This study sought to assess the prevalence of veins and lakes in the skull base on MRI.

MATERIALS AND METHODS

A retrospective review was completed of consecutive patients that underwent contrast-enhanced MRI imaging of the internal auditory canals. The clivus, jugular tubercles, and basio-occiput were assessed for the presence of both intra-osseous veins (serpentine and/or branching vessels) and venous lakes (well-circumscribed round or oval enhancing structures). Vessels in the adjacent synchondroses major foramina were excluded. Three board-certified neuroradiologists performed independent blinded reviews, with discrepancies agreed upon by consensus.

RESULTS

96 patients were included in this cohort (58.3% female). Mean age was 58.4 years (range = 19-85). At least one intra-osseous vessel was identified in 71 (74.0%) patients. 67 (70.0%) had at least one skull base vein, and 14 (14.6%) had at least one venous lake. Both vessel subtypes were observed in 8.3% of patients. Vessels were more commonly observed in women, though this did not reach statistical threshold (p = 0.56). Age was not associated with the presence of vessels (0.59) or vessel location (p values ranged from 0.44-0.84).

CONCLUSIONS

Intra-osseous skull base veins and venous lakes are relatively common findings on MRI. Both vascular structures should be considered normal anatomy, and care should be taken to not confuse these for pathologic entities.

Imaging the Cerebral Veins in Pediatric Patients: Beyond Dural Venous Sinus Thrombosis

The range of intracranial venous anomalies in children differs from that in adults. As a commonly encountered highly morbid disease, sinovenous thrombosis has been discussed extensively in the literature, and the associated imaging considerations are similar in pediatric and adult patients. The authors shift the focus to less frequently discussed cerebral venous diseases in pediatric patients. First, the practical embryology pertinent to malformations, syndromes, and variants such as vein of Galen aneurysmal malformation, Sturge-Weber syndrome, and developmental venous anomalies are discussed. Second, anatomic considerations that are applicable to neuroimaging in pediatric patients with cerebral venous anomalies are reviewed. In the discussion of anatomy, special attention is given to the medullary venous system that serves the cerebral white matter, superficial cortical veins (tributaries of the dural venous sinuses), and bridging veins, which carry blood from the superficial cortical veins through the potential subdural space into the dural venous sinuses. Third, the selection of imaging modalities (US, CT and CT venography, and MRI) is addressed, and various MR venographic pulse sequences (time-of-flight, phase-contrast, and contrast-enhanced sequences) are compared. Finally, a broad variety of congenital and acquired superficial and deep venous diseases in children are reviewed, with emphasis on less frequently discussed entities involving the medullary (eg, deep medullary venous engorgement and thrombosis, periventricular hemorrhagic venous infarction due to germinal matrix hemorrhage), cortical (eg, cortical venous thrombosis), and bridging (eg, acute and chronic manifestations of injury in abusive head trauma) veins, as well as the deep veins and dural venous sinuses (eg, varix). © RSNA, 2023 Quiz questions for this article are available through the Online Learning Center. Online supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article.

Imaging of Chronic Kidney Disease-Mineral and Bone Disorder

The characteristic radiological appearances of metabolic bone and soft tissue diseases in chronic renal failure are described and illustrated in the context of advancing understanding of the complex metabolic changes that occur in chronic kidney disease and its management.