Comparison of Rapid Cranial MRI to CT for Ventricular Shunt Malfunction

Abstract

WHAT'S KNOWN ON THIS SUBJECT: Rapid cranial MRI is a radiation-free method to assess children with possible ventricular shunt malfunction. However, the test performance of rapid cranial MRI has never been compared with that of cranial CT, the current reference standard. WHAT THIS STUDY ADDS:The accuracy of rapid cranial MRI was not inferior to that of CT for diagnosing ventricular shunt malfunction. Rapid cranial MRI is an important radiation-sparing diagnostic alternative for children presenting emergently with possible ventricular shunt malfunction. abstract OBJECTIVES: To compare the accuracy of rapid cranial magnetic resonance imaging (MRI) with that of computed tomography (CT) for diagnosing ventricular shunt malfunction. METHODS:We performed a single-center, retrospective cohort study of children #21 years of age who underwent either rapid cranial MRI or cranial CT in the emergency department (ED) for evaluation of possible ventricular shunt malfunction. Each neuroimaging study was classified as "normal" (unchanged or decreased ventricle size) or "abnormal" (increased ventricle size). We classified a patient as having a ventricular shunt malfunction if operative revision for relief of mechanical causes of altered shunt flow was needed within 72 hours of initial ED evaluation. Our primary analysis tested noninferiority of the accuracy of rapid cranial MRI to CT for diagnosing shunt malfunction (noninferiority margin 10%). RESULTS:We included 698 ED visits for 286 unique patients, with a median age at visit of 10.0 years (interquartile range 5.9-15.5 years). Patients underwent CT in 336 (48%) or rapid cranial MRI in 362 (52%) of ED visits for evaluation of possible shunt malfunction. Patients had operative revision for ventricular shunt malfunction in 140 ED visits (20%). The accuracy of rapid cranial MRI was not inferior to that of CT scan for diagnosing ventricular shunt malfunction (81.8% MRI vs 82.4% CT; risk difference 2.0%; 95% confidence interval, -4.2% to 8.2%).CONCLUSIONS: Rapid cranial MRI was not inferior to CT for diagnosing ventricular shunt malfunction and offers the advantage of sparing a child ionizing radiation exposure. Pediatrics 2014;134:e47-e54

Magnetic resonance imaging acquisition techniques intended to decrease movement artefact in paediatric brain imaging: a systematic review

“…Six studies compared ultra-fast MRI techniques to conventional MRI techniques [13][14][15][16][17][18]; eight reviewed the clinical use of ultra-fast techniques [6][7][8][19][20][21][22][23]; one compared two ultrafast techniques [24]; one compared ultra-fast and standard MRI to CT [25]; and one compared ultra-fast MRI to CT [26]. Six studies compared techniques using oversampling of k-space to conventional MRI [9,[27][28][29][30][31]; and one compared an ultra-fast technique to a technique using oversampling of kspace [32].…”

“…Eighteen studies assessed the use of ultra-fast MRI techniques [6][7][8][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. These studies are listed in Table 2.…”

“…The most frequently investigated ultra-fast sequence was a T2-weighted single-shot fast spin-echo (FSE) sequence. In 11 studies, the ultra-fast MRI consisted only of a single-shot FSE sequence [6,8,13,15,18,19,21,22,26,32]. In four studies a T1-weighted gradient echo (GRE) sequence was used in addition to the T2-weighted single-shot FSE sequence [7,16,17,24].…”

“…Two studies compared ultra-fast MRI with CT [25,26]. Griffiths et al [25] assessed unselected acute admissions requiring CT and performed ultra-fast MRI sequences along with standard MRI sequences within 18 h of the admission CT.…”

“…The authors stated that all pathology was visible on the single-shot FSE and echoplanar sequences except subarachnoid haemorrhage [25]. Boyle et al [26] retrospectively compared two groups of children presenting to the emergency department with suspected shunt malfunction. One group had undergone ultra-fast MRI and the other group had undergone CT [26].…”