Dual-energy computed tomography angiography-based quantification of lesion net water uptake to identify stroke onset time.

Objectives: To explore whether dual-energy computed tomography (DECT) angiography can provide reliable quantitative information on net water uptake (NWU) of ischemic brain to identify stroke patients within 4.5 h. Methods: We retrospectively reviewed 142 patients with stroke occurrence and who underwent DECT angiography between August 2016 and May 2022. DECT angiography manual drawn the ischemic area by referring to the normal area of the contralateral hemisphere and follow-up images. The NWU in the ischemic area was determined using virtual non-contrast and monoenergetic (VNC &VM) images acquired from DECT angiography. The NWU values in the ischemic area were compared between stroke patients within and beyond 4.5 h. The diagnostic performance of the NWU values derived from the VNC and VM images was assessed through receiver operating characteristic curve analysis. Additionally, Furthermore, we examined the correlation between the NWU values and the stroke onset time. Results: Seventy-eight (54.93 %) stroke patients underwent DECT angiography and within 4.5 h. These patients with lower median National Institute of Health stroke scale (NIHSS) scores on admission than those beyond 4.5 h (p < 0.05). Furthermore, the group within 4.5 h had lower NWU values than did the group beyond 4.5 h on all VNC and VM images (p < 0.001). The analysis revealed that the NWU values determined using the VM (60 keV) images had the highest predictive efficiency (AUC, 0.95; sensitivity, 100 %; and specificity, 89.06 %) and showed the strongest positive correlation with stroke onset time (r-value = 0.58, p < 0.001). Conclusions: Our findings showed that DECT angiography-based quantification of NWU helps identify the stroke patients within 4.5 h with high predictive efficiency. Thus, NWU values determined using VM (60 keV) images could serve as a significant biomarker for stroke onset time.

CT and MRI features of struma ovarii / 实用放射学杂志

Objective To investigate the diagnostic value of CT and MRI in struma ovarii (SO).Methods Imaging features of 9 cases with SO confirmed by pathology were analyzed retrospectively.9 patients underwent CT,3 cases underwent both CT and MRI, which were both pre-and post-contrast enhancement.The location,size,shape,margin,density or signal intensity of the lesion,as well as the enhancement patterns of the cystic wall and solid components were observed.Results 7 tumors were located in the right ovary and 2 in the left,with smooth margins and clear boundary.The diameters of the lesions were 5-1 5 cm.The tumors were round in 2 cases,oval round in 2 cases and irregular in 5 cases.9 tumors all appeared cystic-solid type,mainly muti-cystic.The cystic components showed heterogeneous density on CT,mostly low signal intensity on T1WI and high signal intensity on T2WI,few cystic components showed high signal intensity on both T1WI and T2WI.Calcifications were found in 3 cases and fat in 2 cases.The solid components showed slightly high density on plain CT scanning and enhanced markedly either on CT or MRI.6 cases were accompanied with hysteromyomas and 2 cases with ovarian embryoma in the contralateral ovary.Conclusion CT and MRI appearances of SO have a certain characteristic,often manifested as a unilateral adnexal cystic-solid mass and the solid components obviously enhancement,but the boundary is smooth and clear.CT and MRI have different advantages.

CT and MRImaging of gynecological acute abdomen / 实用放射学杂志

Objective To explore the manifestations and diagnostic value of CT and MRI in gynecological acute abdomen.Methods CT and MRI features of 45 patients with gynecological acute abdomen proved by surgery were reviewed,including 17 ectopic pregnancy,10 ovarian cyst rupture,6 pedicle torsion of ovarian tumors,9 tubo-ovarian abscess and pelvic inflammation and 3 uterine perforation.31 cases underwent CT examination,14 cases underwent MRI examination and 39 cases underwent non-enhancement and enhancement scanning.Results In the 17 ectopic pregnancy cases,cystic structure surrounded by a thick wall or heterogeneous mass located in adnexal area was found,with 10 cases showing increased number of peripheral vessels penetrating into tumors.In the 10 cases with rupture of ovarian cyst, thick capsule wall was incomplete and cystic cavities collapsed in 7 lesions.In the 6 cases with pedicle torsion of ovarian tumors,irregular thickening of tumor pedicle were found in 4 cases,ovarian enlargement with surrounding follicles arrayed as fruit platter were found in 2 cases.In the 9 cases with tubo-ovarian abscess and pelvic inflammation,honeycomb-shaped lesions and multilocular changes were found in 6 cases and fallopian tube expanded like sausages in 5 cases.3 cases with uterine perforation exhibited intrauterine gas and fluid.Uterus with overflowed gas was found in 2 cases.One case had the thin and incomplete uterine wall.Conclusion CT and MRI can be used to confirm the causes of gynecological acute abdomen,and to comprehensively display the anatomical structures and pathological changes of pelvic tissues and organs.Therefore,CT and MRI are effective supplement means for the clinical diagnosis of gynecological acute abdomen.

Diagnostic values of normalized ADC value in benign and malignant breast lesions / 实用放射学杂志

Objective To evaluate the values of DWI normalized ADC value in breast MRI in the differential diagnosis of benign and malignant breast lesions.Methods The absolute value of ADC,normalized ADC value and T1 WI dynamic contrast-enhanced TIC were analyzed in 49 patients with benign and malignant breast lesions;the efficiencies of single method diagnosis and combined diagnosis were assessed.Results When b=1 000 s/mm2 ,the absolute value of ADC <1.25×10 -3 mm2/s was taken as the thresh-old value for the diagnosis of malignant breast lesions,the area under the ROC curve was 0.818,the sensitivity was 73.9% and the specificity was 84.6%;the normalized ADC value <0.55 × 10 -3 mm2/s was taken as the diagnostic threshold,the area under the ROC curve was 0.901,the sensitivity was 87.0% and the specificity was 88.5%,there was a significant difference between both values.The lesions with a wash-out type of T1 WI dynamic contrast-enhanced TIC were diagnosed as malignant lesions,the sensitivi-ty was 89.5% and the specificity was 70.0%.The absolute value of ADC and T1 WI dynamic contrast-enhanced TIC were applied combinedly,the predicted percentage correct was 81.6% for the diagnosis of breast lesions,while the normalized ADC value and T1 WI dynamic contrast-enhanced TIC were applied combinedly,the predicted percentage correct was increased,which was 89.8%. Conclusion Normalized ADC value has a higher sensitivity and specificity in differentiating benign and malignant breast lesions,its combined application with T1 WI dynamic contrast-enhanced TIC can improve the diagnostic performance of breast lesions.

Study of white matter tractography in patients with amnestic mild cognitive impairment / 实用放射学杂志

Objective To investigate subtle structural changes of white matter in patients with amnestic mild cognitive impair-ment (aMCI)using a tractography-based method.Methods Thirty patients with clinical diagnosis of aMCI and thirty-one cases of normal control(NC)and undergone diffusion tensor imaging.Cingulum (CG),corpus callosum (CC),uncinate fasciculus (UNC) and inferior occipitofrontal fasciculus (IOFF)were reconstructed,and fractional anisotrophy (FA)values were measured along these tracts using dTV II software.Differences of white matter tracts’FA values were explored between aMCI group and NC group.In addition,correlation analyses were also done between FA values and the MMSE(mini-mental state examination)scores in the aMCI patients.Results ① aMCI patients exhibited significant lower FA values in the bilateral CG,bilateral UNC and CC than NC group. Although there were no statistically significant differences,aMCI patients exhibited lower FA values than NC group in the left IOFF.② The FA values of right CG were positively correlated with MMSE scores.Conclusion Abnormal changes of FA values in CG,UNC and CC of aMCI patients suggest that subtle damages of white matter tracts related to memory exist in the prodromal phase of Alzheimer’s disease (AD).Fiber tractography has high sensitivity in detecting early damages of white matter.

Traumatic diaphragmatic rupture: the diagnostic value of multiplanar reformation in multi-slice spiral CT examination / 中华放射学杂志

Objective To investigate the diagnostic value of multiplanar reformation (MPR)reconstruction for the detection of traumatic diaphragmatic rupture (TDR) in multi-slice CT examination.Methods Thirty six cases with thoracoabdominal trauma, including 21 cases with and 15 cases without TDR confirmed by surgery, received multi-slice CT examination. They were enrolled in this study. Three experienced radiologists retrospectively analyzed the axial and MPR images. The diagnostic criteria for TDR included abnormally elevated hemidiaphragm, diaphragmatic discontinuity, the "collar sign" or "dependent viscera "sign. Referenced to surgical results, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of axial and MPR images in detection of TDR were calculated. The McNemar was used to investigate the differences between axial and MPR images in the detection of diaphragmatic discontinuity and "collar sign", and the differences between axial and MPR images of these two signs in TDR diagnosis. Results The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of axial images in detection of TDR were 71% ( 15/21 ), 80% ( 12/15 ), 83% ( 15/18 ),67% ( 12/18 ) and 75% ( 27/36 ), respectively; of MPR images, they were 86% ( 18/21 ), 93%(14/15), 95% ( 18/19 ), 82% ( 14/17 ) and 89% ( 32/36), respectively. By axial images, twelve diaphragmatic defects or interrupts were identified in nine cases, and "collar sign" was identified in six cases. By MPR, 20 diaphragmatic defects or interrupts were identified in 15 cases ( P = 0.125 ), and "collar sign" was identified in 14 cases (P =0.021 ). The sensitivity and specificity of diaphragmatic defects or interrupts for TDR diagnosis in axial images were 43% (9/21) and 80% ( 12/15 ), respectively;in MPRimages, they were71% (15/21) (P=0.125)and93% (14/15) (P=0.500), respectively.The sensitivity and specificity of "collar sign" for TDR diagnosis in axial images were 29% (6/21) and 100% ( 15/15), respectively; in MPR images, they were 67% ( 14/21 ) (P =0. 021 ) and 100% (15/15)( P = 1.000), respectively. Conclusions MSCT presented good sensitivity, specificity and accuracy for the diagnosis of TDR. MPR images were useful supplements for axial images in TDR diagnosis which improved the diagnosis.