Objective To evaluate the value of an optimized three-dimensional inversion-recovery with real reconstruction (3D-real IR) sequence with a longer repetition time (TR, 16 000 ms) based on modulated flip angle technique in refocused imaging with extended echo train (MATRIX) in the endolymphatic hydrops (EH) imaging after intratympanic gadolinium (Gd) administration, and to compare it with a conventional 3D-real IR based on the turbo spin echo (TSE) sequence. Methods From July 2021 to November 2022, twenty-seven patients received both the conventional and optimized 3D-real IR sequences after bilateral intratympanic Gd administration. Images of the two sequences were qualitativly evaluated and compared. Contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR), and area ratio of endolymph against the total lymphatic space from the two sequences were measured and compared. Results 14(25.9%) ears with insufficient contrast for the EH diagnosis on the conventional sequence were clearly displayed on the optimized sequence. Image score, CNR and SNR of the optimized sequence were significantly higher than those of the conventional sequence (P ＜ 0.001). The scanning time of two sequences was similar. The area ratio of endolymph against the total lymphatic space in the cochlear was significantly higher on the conventional 3D-real IR than that on the optimized 3D-real IR (P ＜ 0.001); there was no statistical difference in the vestibule between the two sequences. Conclusions Compared with conventional sequence, optimized 3D-real IR sequence with a longer TR may be better for evaluation of EH after intratympanic Gd administration.

Objective To investigate the value of artificial intelligence-assisted compressed sensing (ACS) technology for intravenous gadolinium contrast-enhanced magnetic resonance imaging of the inner ear using three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) sequence. Methods The patients received gadolinium contrast-enhanced magnetic resonance imaging using ACS and united compressed sensing (uCS) 3D-FLAIR at Zhongshan Hospital, Fudan University from January to November 2024 were prospectively enrolled. The repetition time was 16 000 ms, and acquisition time was 6 min 40 s and 10 min 24 s in ACS 3D-FLAIR and uCS 3D-FLAIR, respectively. The images on the two sequences were evaluated independently by two radiologists. The image quality of the two sequences was subjectively evaluated and compared. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were compared between the two sequences. The grading consistencies using two sequences and between the two doctors were analyzed. Results There was no statistically difference in subjective score of image quality between the two sequences. SNR and CNR of the ACS 3D-FLAIR sequence were significantly higher than those of the uCS 3D-FLAIR sequence (P＜0.001). The kappa values of grades of cochlear and vestibular endolymphatic hydrops were 0.942 and 0.888 using two sequences (P＜0.001). The kappa values of grades of cochlear and vestibular endolymphatic hydrops using the ACS 3D-FLAIR sequence between the two doctors were 0.784 and 0.831, respectively (P＜0.001); the kappa values of grades of cochlear and vestibular endolymphatic hydrops using uCS 3D-FLAIR sequence between the two doctors were 0.725 and 0.756, respectively (P＜0.001). Conclusions ACS 3D-FLAIR could provide higher SNR and CNR than uCS 3D-FLAIR, and is more suitable for intravenous gadolinium contrast-enhanced magnetic resonance imaging of the inner ear; the endolymphatic hydrops grades using ACS 3D-FLAIR is similar to use uCS 3D-FLAIR.

Objective To investigate the MRI features of primary retroperitoneal leiomyosarcoma(PRLS).Methods Thirty-three cases of pathologically confirmed PRLS were analyzed retrospectively,and their multi-parameter MRI features were analyzed qualitatively and quantitatively.Results Of the 33 PRLS,24 cases were located in the renal hilum,inferior vena cava,or the area around the bifurcation of the iliac vessels.Twenty-four cases had relatively intact capsule,25 cases had necrosis,and 15 cases had coagulated geographic necrosis.The mean diameter of the tumors was(9.9±5.1)cm,ranging from 3.0 to 20.7 cm,among which 27 cases with a diameter larger than 5 cm.The tumor parenchyma of the 33 PRLS all showed significantly high signal intensity on diffusion weighted imaging(DWI),and significantly low signal intensity on apparent diffusion coefficient(ADC)map.The tumor parenchyma showed moderate to obvious degree of progressive enhancement,and the signal intensity value of the tumor in each phase after contrast injection was higher than that of the psoas major muscle(P＜0.001).Conclusion PRLS are usually large but have a relatively intact capsule and are closely related to the major retroperitoneal veins.The coagulated geographic necrosis,significantly limited diffusion of water molecules,and progressive enhancement pattern all show certain MRI characteristics.

In recent years,with the rapid development of modern medical technology,new ideas and new concepts of hepatocellular carcinoma have emerged endlessly.In this context,China's liver cancer experts have once again updated the'Primary Liver Cancer Diagnosis and Treatment Guidelines"in 2024,to provide guidance for domestic HCC diagnosis and treatment.Now,the imaging group of this updated guideline will interpret the main updates and highlights of imaging,and further promote the standardization process of liver cancer imaging diagnosis in China.

Objective:To explore the magnetic resonance imaging (MRI) features and classification of intraductal papillary neoplasm of the bile duct (IPNB).Methods:Data from 90 patients with intraductal papillary neoplasm of the bile duct confirmed pathologically between June 2010 and January 2023 were retrospectively analyzed. The image analysis included the shape and location of the tumor, whether bile ducts had dilatation and the degree of dilation, whether there was a history of liver disease, whether there was a history of schistosomiasis, whether there was cancerous transformation, whether there were concurrent bile duct stones, whether there was hepatic lobe atrophy, whether there was hilar or abdominal lymph node enlargement, whether there was invasion of the bile duct wall, whether there was invasion of surrounding blood vessels, whether the tumor appears on T1-and T2 weighted imaging (T 1WI and T 2WI), whether the diffusion was limited, whether there was concurrent bleeding, enhancement rate, and whether there was abdominal fluid accumulation. Intraductal papillary neoplasms of the bile duct were divided into four types according to the morphological classification standards: type I (local bile duct dilation), type II (cystic), type III (free tumor), and type IV (dilated bile duct). The differences in the clinical and MRI features of the four groups of lesions were analyzed. Statistical analysis was performed with a t-test, an analysis of variance, and an χ2-test according to the different data. Results:Among the 90 cases with hepatic IPNB, there were 31 cases of type I, 15 cases of type II, 16 cases of type III, and 28 cases of type IV, 41 cases of liver left lobe, 11 cases of right and left lobe liver span, 7 cases of liver right lobes, 2 cases of liver caudate lobe, and 13 cases of hepatic hilar. There were statistically significant differences between the four groups ( P ??0.05). Conclusion:MRI manifestations have certain features for different types of intraductal papillary neoplasm of the bile duct tumors; hence, MRI aids in the diagnosis and differential diagnosis of this disease.

Objective:To explore the MRI characteristics of the hepatic epithelioid hemangioendothelioma (HEHE) classification according to morphology and size.Methods:The clinical, pathological, and MRI imaging data of 40 cases with HEHE confirmed pathologically from December 2009 to September 2021 were retrospectively analyzed. A paired sample t-test was used for comparison between the two groups. Results:There were 40 cases (5 solitary, 24 multifocal, 9 local fusion, and 2 diffuse fusion) and 214 lesions (163 nodules, 31 masses, and 20 fusion foci). The most common features of lesions were subcapsular growth and capsular depression. The signal intensity of lesions ≤1cm was usually uniform with whole or ring enhancement. Nodules and mass-like lesions ≥1cm on a T1-weighted image had slightly reduced signal intensity or manifested as a halo sign. Target signs on a T2-weighted image were characterized by: target or centripetal enhancement; fusion-type lesions; irregular growth and hepatic capsular retraction, with ring or target-like enhancement in the early stage of fusion and patchy irregular enhancement in the late stage; blood vessels traversing or accompanied by malformed blood vessels; focal bleeding; an increasing proportion of extrahepatic metastases and abnormal liver function with the type of classified manifestation; primarily portal vein branches traversing; and reduced overall intralesional bleeding rate (17%). Lollipop signs were presented in 19 cases, with a high expression rate in mass-type lesions (42%). The fusion lesions were expressed, but the morphological manifestation was atypical. The diffusion-weighted imaging mostly showed high signal or target-like high signal. An average apparent diffusion coefficient of lesions was (1.56±0.36) ×10 -3mm 2/s, which was statistically significantly different compared with that of adjacent normal liver parenchyma ( t=8.28, P<0.001). Conclusion:The MRI manifestations for the HEHE classification are closely related to the morphology and size of the lesions and have certain differences and characteristics that are helpful for the diagnosis of the disease when combined with clinical and laboratory examinations.

Objective To observe the value of 5.0T MR susceptibility weighted imaging(SWI)for displaying cerebral small veins and detecting cerebral microbleeds(CMB).Methods Head MR examinations were prospectively performed using both 3.0T and 5.0T MR scanner in 30 stroke patients suspected caused by cerebral small vessel disease.The image quality,effect of displaying cerebral small veins and detecting CMB were compared between 3.0T and 5.0T SWI.Results The image quality scores,signal-to-noise ratios,contrast-to-noise ratios,scores of displaying deep cerebral veins and subcortical veins,the counts of detecting CMB and iron deposition on cortical surface of 5.0T SWI were all higher than those of 3.0T SWI(all P＜0.05).High consistency of CMB positions was found between 3.0T and 5.0T SWI(Kappa=1.0).Conclusion The effect of 5.0T MR SWI for displaying cerebral small veins and detecting cerebral microbleeds were better than 3.0T MR SWI,which could be used to assess stroke caused by cerebral small vascular disease.

Objective To observe the value of long TR three-dimensional inversion recovery sequence with real reconstruction(3D real IR)for quantifying inner ear endolymphatic hydrops(EH).Methods Totally 46 Ménière's disease(MD)patients and 21 healthy volunteers were prospectively enrolled.MR scanning for inner ear based on 3D real IR and 3D fluid attenuated inversion recovery(3D FLAIR)sequence 4-6 h after administration of contrast agents were performed.The imaging qualities were scored and compared between groups.The endolymphatic space area and the membranous labyrinth area of cochlea and vestibule,as well as endolymph/membranous labyrinth area percentage were calculated,the present or not of EH and the grade of EH were evaluated.EH inner ears of MD patients were enrolled in EH group,while inner ears of healthy volunteers were taken as controls(control group).The endolymphatic space area,membranous labyrinth area and endolymph/membranous labyrinth area percentage of cochlea and vestibule were compared between groups.The receiver operating characteristic(ROC)curve was drawn to calculate the diagnostic efficacy of the above indexes.Results Cochlear and/or vestibular EH were detected in 56 ears,including cochlear EH in 52 ears and vestibular EH in 45 ears among 46 MD patients(EH group),but not in 42 ears in control group.The subjective quality scores of 3D real IR images were higher than those of 3D-FLAIR(both P＜0.05).Quantitative analysis based on 3D real IR images revealed that,compared with control group,significantly larger endolymph areas and endolymph/membranous labyrinth area percentages in both cochlea and vestibule were found in EH group(all P＜0.001).The area under the curve(AUC)of cochlear or vestibular endolymph/membranous labyrinth area percentage for identifying inner ear EH was 0.999 and 0.985,respectively.Taken 13.64％and 24.13％as the critical value of cochlear or vestibular endolymph,the specificity was 100％and 92.86％,respectively,and the sensitivity was 96.43％and 96.43％,respectively.Conclusion MR long TR 3D real IR was helpful to quantifying inner ear EH.

Objective:To investigate the feasibility of multi-slice spiral CT (MSCT) imaging feature of gastric stromal tumor (GST) in evaluating Ki-67 index expression .Methods:The clinical and CT imaging data of 501 patients with GST confirmed by surgery and pathology were retrospectively studied in Zhongshan Hospital affiliated to Fudan University and the Affiliated TCM Hospital of Southwest Medical University from Nov 2014 to Nov 2021. By immunohistochemical results, tumors were divided into Ki-67 low expression group (Ki-67≤6%, 335 lesions) and high expression group (Ki-67>6%, 168 lesions). Multivariate logistic regression analysis was conducted.Results:Between the two groups,there were statistical differences in the longest and shortest diameter of tumor, CT value on venous phase, CT attenuation value ( Z=4.80, 4.91, 3.21, 3.29, all P<0.01) and tumor location,morphology, necrosis, ulcer, feeding artery, vascular enhancement, positive fat sign around disease, gastrointestinal bleeding ( χ2=10.77, 13.49, 8.59, 22.87, 7.59, 7.23, 7.76, 8.58, all P<0.05). Tumor ulceration positive ( OR=1.88, 95%CI: 1.17-3.03) was independent risk factor of Ki-67 high expression ( P=0.009). Gastric antrum was used as the reference for tumor location, cardia ( OR=5.41, 95% CI:1.25-23.46) was independent risk factor of Ki-67 high expression ( P=0.024). Conclusion:MSCT has a definite predictive value for the expression in Ki-67 index of GST cases.

Objective:To evaluate the value of a three-dimensional inversion-recovery with real reconstruction (3D-real IR) sequence with an ultralong repetition time (TR) for the endolymphatic hydrops (EH) of Meniere disease (MD) after intravenous gadolinium administration, and compare it with a heavily T 2-weighted three-dimensional fluid-attenuated inversion recovery (hT 2-3D-FLAIR) sequence. Methods:From July 2021 to July 2022, 52 definite MD patients (58 ears) were retrospectively enrolled at Zhongshan Hospital, Fudan University. The 3D-real IR with an ultralong TR (16 000 ms) and hT 2-3D-FLAIR sequences were performed four hours after intravenous single-dose gadolinium administration. The image quality of the two sequences was rated. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were measured in the two sequence. The EH of cochlear and vestibular was graded, and EH detection rates were calculated. Scores of the two sequences were compared using the paired Wilcoxon signed rank test. Paired t test was used to compare the differences of the SNR and CNR. McNemar test was performed to compare the EH detection rate between the two sequences. Results:The score of the 3D-real IR [3 (3, 4)] was significantly higher than that of the hT 2-3D-FLAIR [2.5 (2, 3), Z=-6.06, P<0.001]. No significant difference was found in SNR of 3D-real IR and hT 2-3D-FLAIR (11.4±6.5 and 12.3±3.7, t=-1.38, P=0.175). CNR of the 3D-real IR (21.7±9.3) was significantly higher than that of the hT 2-3D-FLAIR (9.7±3.8, t=10.67, P<0.001). Using 3D-real IR sequence, the EH detection rate of cochlear (89.7%, 52/58) was higher than using hT 2-3D-FLAIR (67.2%, 39/58, χ 2=11.10, P<0.001). No significant difference was found in the EH detection rate of vestibular between 3D-real IR (77.6%, 45/58) and hT 2-3D-FLAIR (74.1%, 43/58, χ 2=0.50, P=0.500). Conclusion:Compared with hT 2-3D-FLAIR sequence, the 3D-real IR with an ultralong TR can improve the depiction of EH in MD patients after intravenous single-dose gadolinium administration. It can provide higher image quality and detection rate of EH.