Pediatric whole‐body MRI: A review of current imaging techniques and clinical applications

Abstract

There are many congenital, neoplastic, inflammatory, and infectious processes in the pediatric patient for which whole-body imaging may be of benefit diagnostically and prognostically. With recent improvements in magnetic resonance imaging (MRI) hardware and software and resultant dramatically reduced scan times, imaging of the whole body with MRI has become a much more practicable technique in children. Whole-body MRI can provide a high level of soft tissue and skeletal detail while avoiding the exposure to ionizing radiation inherent to computed tomography and nuclear medicine imaging techniques. This article reviews the more common current whole-body MRI techniques in children and the primary pathologies for which this imaging modality may be most useful to the radiologists and referring clinicians. J. MAGN. RESON. IMAGING 2016;44:783-793.

Pediatric Cancer Predisposition Imaging: Focus on Whole-Body MRI

“…Considerable site-to-site variations arise from differing scanner platforms and technological capabilities, the tumors and syndromes under surveillance, and departmental/radiologist preference. The most recent published protocols specific for WBMRI in pediatric oncology utilize a fluid-sensitive sequence in the coronal plane, with additional optional sequences and imaging planes (1,(6)(7)(8)(17)(18)(19), and are summarized in Table 2. As documented in the table, scan times vary significantly between protocols depending on number and type of sequences used.…”

“…Coronal short tau inversion recovery (STIR) is the sequence central to most WBMRI protocols, displaying most pathologic lesions as bright signal against a darker background due to its robust fat suppression (1,(6)(7)(8). Fat-suppressed T2-weighted sequences provide an alternative fluid-sensitive sequence; however, these sequences rely on chemically selective fat suppression techniques that can be inhomogeneous in non-axial acquisition planes, resulting in artifacts when transitioning between certain regions of the body (e.g., neck and supraclavicular chest).…”

“…T1-weighted sequences are also variably applied to aid lesion localization and tissue characterization for certain CPS. Few screening protocols routinely include GBCA-enhanced sequences (1,(6)(7)(8).…”

“…One pediatric study by Nievelstein and Littooij compared WBMRI with PET/CT and found MRI was better able to identify bony infiltrates <12 mm (8). Although lung nodules are increasingly identified on WBMRIsome studies showing high sensitivities for lesions between 4 and 10 mm-WBMRI screening for pulmonary metastases is not yet advocated, and chest CT remains the reference standard (5,6 As well as a systematic approach and detailed knowledge improving lesion detection, as Anupindi and colleagues highlighted, it is equally important to carry out "risk stratification" to minimize false positive findings (18). WBMRI is only one part of a surveillance program, and findings should be interpreted in conjunction with other clinical and imaging data (17,18).…”

“…The use of whole-body magnetic resonance imaging (WBMRI) for surveillance of infants, children, and adolescents with cancer predisposition syndromes (CPS) has grown over the past decade, in line with more widespread adoption of WBMRI for a range of pediatric oncologic indications (1)(2)(3)(4)(5)(6)(7)(8). This has been due to a combination of factors including technologic improvements enabling more rapid acquisition, greater access to MRI, as well as increased awareness of its expanding applications (1,5,9).…”