T2-weighted balanced steady-state free procession MRI evaluated for diagnosing placental adhesion disorder in late pregnancy.

OBJECTIVE: This study evaluated the imaging characteristics and accuracy of T2-weighted (T2W) balanced steady-state free procession (b-SSFP) magnetic resonance imaging, relative to b-SSFP or single-shot fast spin echo (SSFSE), for the diagnosis of placental adhesion disorder (PAD). METHODS: Fifty-one pregnant patients suspected of PAD were examined with T2W b-SSFP, b-SSFP and SSFSE. The image types were independently analysed for signs of PAD: abnormal placental bulge (APB), dark intraplacental bands (DIB), placental heterogeneity (PH) and placental protrusion into adjacent structures (PPAS). The sequences were compared for muscle-to-placenta signal ratio, signs of PAD and area under the receiver operating characteristic curve (AUC) for diagnostic accuracy of PAD. RESULTS: PAD was confirmed in 34 women. The muscle-to-placenta signal ratio was highest in the T2W b-SSFP. The diagnostic rates of APB in T2W b-SSFP were comparable to that of b-SSFP, but were significantly higher than that of SSFSE. The rates of PH in SSFE were comparable to that of b-SSFP, but both were significantly lower than that of T2W b-SSFP. The rates of DIB were significantly higher in T2W b-SSFP images compared with SSFSE. Rates of PPAS were comparable among three sequences. The AUCs of the T2W b-SSFP, b-SSFP and SSFSE were 0.966, 0.890 and 0.823, respectively. CONCLUSION: T2W b-SSFP has high diagnostic accuracy for PAD relative to SSFSE or b-SSFP, which may be due to its high SNR, T2-weighting and lack of blur. KEY POINTS: • Signal myometrium-to-placenta ratio was highest in the T2W b-SSFP images. • Diagnostic rate of APB in T2W b-SSFP was highest. • Diagnostic rate of DIB was higher in T2W b-SSFP than in SSFSE. • Diagnostic rate of PH in T2W b-SSFP was highest. • Maximum AUC for diagnostic accuracy of PAD was in T2W b-SSFP.

A Multimodal Magnetic Resonance Imaging Study of Recovery of Consciousness in Severe Traumatic Brain Injury: Preliminary Results.

Accurate and reliable assessment of the conscious state of patients with severe traumatic brain injury (TBI) is vital for their future management. The purpose of the present study is to find an effective and accurate magnetic resonance imaging (MRI) method for predicting recovery of consciousness in patients with severe TBI. Multimodal MR techniques, including structural MRI, MR spectroscopy (MRS), diffusion tensor imaging (DTI), were used to evaluate brain damage in 58 patients with severe TBI. Statistical analysis compared imaging results and recovery over a relatively long period to find the most potent prognostic indicators and predictive method. A total 33 patients gained recovery of consciousness (RC), and 25 did not (NRC). Compared with the RC group, those in the NRC group had a significantly lower N-acetylaspartate to creatine (NAA/Cr) ratio of pons (1.43 ± 0.54 vs. 1.70 ± 0.42), more fiber lines (1046.3 ± 100.8 vs. 975.6 ± 128.1), less peripheral grey matter (pgrey) (579.23 ± 78.85 vs. 638.23 ± 61.16), lower fractional anisotropy (FA) of fibers (0.42 ± 0.04 vs. 0.45 ± 0.03), older age (43.08 ± 14.61 vs. 30.57 ± 12.89), and higher apparent diffusion coefficient (ADC) of fibers (0.99 ± 0.14 vs. 0.89 ± 0.06); all p < 0.05. Age, pgrey, ADC of fibers, NAA/Cr of pons were selected by logistic regression analysis to predict RC, with p values of 0.033 and 0.031, 0.035, 0.030, respectively. Age, pgrey, ADC of fibers, NAA/Cr of pons are effective indicators in the predictive model of RC.