Objective:To study the CT and MRI features of xanthogranulomatous cholecystitis (XGC).Methods:Clinical data of 41 patients with XGC admitted to Yueqing Third People's Hospital, Yueqing People's Hospital and Wenzhou Central Hospital from January 1, 2013 to December 30, 2023 were retrospectively analyzed, including 21 males and 20 females, aged 63 (61, 65) years. Data including gender, age, clinical manifestations, CT and MRI features, were recorded.Results:Of the 41 patients, 26 had clinical manifestations of upper abdominal pain accompanied by nausea, vomiting, and fever, and 15 had upper abdominal pain accompanied by jaundice. Forty-one patients had positive percussion pain in liver area, of which 18 had positive Murphy’s sign and 12 had jaundice of the skin and sclera. Among the 25 patients who underwent CT examination, the gallbladder had a longitudinal diameter of 8 (5, 10) cm and a transverse diameter of 4 (3, 6) cm. The thickness of the thickened gallbladder wall was 1.6 (0.4, 1.9) cm. Most cases show diffuse uneven thickening, and a few cases show uniform diffuse or localized thickening. After enhancement, the thickened gallbladder wall can be seen as " sandwich" - or " sandwich cookie" -like enhancement or layered enhancement. Mucosal line is continuous or discontinuous. Eleven cases with low-density nodules between walls showed no enhancement. Among the 16 patients who underwent routine MRI examinations, the gallbladder had a longitudinal diameter of 8 (5, 10) cm and a transverse diameter of 4 (3, 6) cm. The thickness of the thickened gallbladder wall was 1.6 (0.4, 1.9) cm. Most cases show diffuse uneven thickening, and a few cases show uniform diffuse or localized thickening. There were nine cases of multiple small nodules between walls. The thickened gallbladder wall showed heterogeneous signal on T 1-weighted imaging (T 1WI) and T 2-weighted imaging (T 2WI), presenting equal, high, low, or mixed signals. T 1WI showed low signal intensity in reverse phase. Diffusion weighted imaging fat suppression sequence shows multiple small nodules within the wall with high signal intensity. Nine cases of intramural nodules showed high signal intensity on T 1WI in-phase, T 2WI, and T 2WI fat phase, low signal intensity on T 1WI in-phase, and low signal intensity on T 2WI fat suppression sequence. The wall of gallbladder showed " sandwich" - or " sandwich cookie" -like enhancement or layered enhancement. Mucosal line is continuous or discontinuous. Nine cases of intramural nodules showed no enhancement. Conclusions:The CT and MRI features of XGC are diffuse and uneven thickening with nodules between the gallbladder walls in most cases. Nodules with low density on CT plain scan, high signal on T 1WI in-phase, high signal on T 2WI, and low signal on T 1WI out-phase. The thickening of the gallbladder wall after enhancement is characterized by a " sandwich" - or " sandwich cookie" -like enhancement.

Objective:To analyze the CT and MRI manifestations of hepatic angiomyolipoma (HAML) to improve the diagnostic accuracy of HAML.Methods:A retrospective analysis was conducted on the clinical data of 46 cases of HAML confirmed by tumor surgery or biopsy in Yueqing People's Hospital of Zhejiang and Rui'an People's Hospital of Zhejiang from November 2015 to June 2024. Among them, there were 20 males and 26 females, with an average age of (40±18) years. The CT and MRI manifestations of the patients were recorded, and the tumor location, size, shape, boundary, CT density, T 1-weighted imaging, T 2-weighted imaging, diffusion-weighted imaging (DWI), fat suppression sequence, and inverse phase signal were observed. Results:29 cases underwent plain CT scan combined with enhanced scan. Among them, 4 cases (13.8%) had a round shape, 22 cases (47.8%) had a nearly round shape, and 3 cases (10.3%) had an irregular shape. 26 cases (89.7%) had clear boundaries, and 3 cases (10.3%) had unclear boundaries. 5 cases (17.2%) had uniform density, and 24 cases (82.8%) had non-uniform density. The CT value of the tumor was (32±6.8) Hu. 25 cases (86.2%) contained fat tissue within the tumor. Among them, 13 cases (44.8%) were mixed type. After enhancement, the fat tissue and necrotic cystic changes did not enhance, and the soft tissue components showed varying degrees of enhancement in the arterial phase. Among them, 6 cases continued to enhance in the portal venous phase and delayed phase, showing " fast in and slow out" , and 7 cases showed decreased enhancement in the portal venous phase and delayed phase, showing " fast in and fast out" . 17 cases underwent plain MRI scan combined with enhanced scan. Among them, 12 cases were mixed type. On T 2-weighted imaging with fat suppression, it was a mixed high signal, on T 1-weighted imaging, it was an isointense/low signal or mixed low signal, and on DWI, it was a high signal, with partial signal reduction on the inverse phase. 9 cases of tumor septation showed isointense signals on T 1-weighted imaging, 7 cases showed isointense signals on T 2-weighted imaging, and 2 cases showed high signals on T 2-weighted imaging. After enhancement, the mass showed heterogeneous enhancement, with 7 cases showing " fast in and fast out" and 5 cases showing " fast in and slow out" . Conclusion:Plain CT scan shows that HAML is round or nearly round, with non-uniform low density or uniform isodensity. Plain MRI scan shows isointense or slightly high signal on T 2-weighted imaging, low signal on T 1-weighted imaging, and high signal on T 2-weighted imaging with fat suppression. After enhancement, there is significant or mild to moderate enhancement in the arterial phase, with " fast in and fast out" or " fast in and slow out" as the characteristics.

Objective:To study the CT and MRI features of xanthogranulomatous cholecystitis (XGC).Methods:Clinical data of 41 patients with XGC admitted to Yueqing Third People's Hospital, Yueqing People's Hospital and Wenzhou Central Hospital from January 1, 2013 to December 30, 2023 were retrospectively analyzed, including 21 males and 20 females, aged 63 (61, 65) years. Data including gender, age, clinical manifestations, CT and MRI features, were recorded.Results:Of the 41 patients, 26 had clinical manifestations of upper abdominal pain accompanied by nausea, vomiting, and fever, and 15 had upper abdominal pain accompanied by jaundice. Forty-one patients had positive percussion pain in liver area, of which 18 had positive Murphy’s sign and 12 had jaundice of the skin and sclera. Among the 25 patients who underwent CT examination, the gallbladder had a longitudinal diameter of 8 (5, 10) cm and a transverse diameter of 4 (3, 6) cm. The thickness of the thickened gallbladder wall was 1.6 (0.4, 1.9) cm. Most cases show diffuse uneven thickening, and a few cases show uniform diffuse or localized thickening. After enhancement, the thickened gallbladder wall can be seen as " sandwich" - or " sandwich cookie" -like enhancement or layered enhancement. Mucosal line is continuous or discontinuous. Eleven cases with low-density nodules between walls showed no enhancement. Among the 16 patients who underwent routine MRI examinations, the gallbladder had a longitudinal diameter of 8 (5, 10) cm and a transverse diameter of 4 (3, 6) cm. The thickness of the thickened gallbladder wall was 1.6 (0.4, 1.9) cm. Most cases show diffuse uneven thickening, and a few cases show uniform diffuse or localized thickening. There were nine cases of multiple small nodules between walls. The thickened gallbladder wall showed heterogeneous signal on T 1-weighted imaging (T 1WI) and T 2-weighted imaging (T 2WI), presenting equal, high, low, or mixed signals. T 1WI showed low signal intensity in reverse phase. Diffusion weighted imaging fat suppression sequence shows multiple small nodules within the wall with high signal intensity. Nine cases of intramural nodules showed high signal intensity on T 1WI in-phase, T 2WI, and T 2WI fat phase, low signal intensity on T 1WI in-phase, and low signal intensity on T 2WI fat suppression sequence. The wall of gallbladder showed " sandwich" - or " sandwich cookie" -like enhancement or layered enhancement. Mucosal line is continuous or discontinuous. Nine cases of intramural nodules showed no enhancement. Conclusions:The CT and MRI features of XGC are diffuse and uneven thickening with nodules between the gallbladder walls in most cases. Nodules with low density on CT plain scan, high signal on T 1WI in-phase, high signal on T 2WI, and low signal on T 1WI out-phase. The thickening of the gallbladder wall after enhancement is characterized by a " sandwich" - or " sandwich cookie" -like enhancement.

Objective:To analyze the CT and MRI manifestations of hepatic angiomyolipoma (HAML) to improve the diagnostic accuracy of HAML.Methods:A retrospective analysis was conducted on the clinical data of 46 cases of HAML confirmed by tumor surgery or biopsy in Yueqing People's Hospital of Zhejiang and Rui'an People's Hospital of Zhejiang from November 2015 to June 2024. Among them, there were 20 males and 26 females, with an average age of (40±18) years. The CT and MRI manifestations of the patients were recorded, and the tumor location, size, shape, boundary, CT density, T 1-weighted imaging, T 2-weighted imaging, diffusion-weighted imaging (DWI), fat suppression sequence, and inverse phase signal were observed. Results:29 cases underwent plain CT scan combined with enhanced scan. Among them, 4 cases (13.8%) had a round shape, 22 cases (47.8%) had a nearly round shape, and 3 cases (10.3%) had an irregular shape. 26 cases (89.7%) had clear boundaries, and 3 cases (10.3%) had unclear boundaries. 5 cases (17.2%) had uniform density, and 24 cases (82.8%) had non-uniform density. The CT value of the tumor was (32±6.8) Hu. 25 cases (86.2%) contained fat tissue within the tumor. Among them, 13 cases (44.8%) were mixed type. After enhancement, the fat tissue and necrotic cystic changes did not enhance, and the soft tissue components showed varying degrees of enhancement in the arterial phase. Among them, 6 cases continued to enhance in the portal venous phase and delayed phase, showing " fast in and slow out" , and 7 cases showed decreased enhancement in the portal venous phase and delayed phase, showing " fast in and fast out" . 17 cases underwent plain MRI scan combined with enhanced scan. Among them, 12 cases were mixed type. On T 2-weighted imaging with fat suppression, it was a mixed high signal, on T 1-weighted imaging, it was an isointense/low signal or mixed low signal, and on DWI, it was a high signal, with partial signal reduction on the inverse phase. 9 cases of tumor septation showed isointense signals on T 1-weighted imaging, 7 cases showed isointense signals on T 2-weighted imaging, and 2 cases showed high signals on T 2-weighted imaging. After enhancement, the mass showed heterogeneous enhancement, with 7 cases showing " fast in and fast out" and 5 cases showing " fast in and slow out" . Conclusion:Plain CT scan shows that HAML is round or nearly round, with non-uniform low density or uniform isodensity. Plain MRI scan shows isointense or slightly high signal on T 2-weighted imaging, low signal on T 1-weighted imaging, and high signal on T 2-weighted imaging with fat suppression. After enhancement, there is significant or mild to moderate enhancement in the arterial phase, with " fast in and fast out" or " fast in and slow out" as the characteristics.

Objective:To investigate the characteristics of computed tomography(CT) and magnetic resonance imaging(MRI)of focal peliosis hepatis (PH).Methods:From January 1, 2015 to December 31, 2022, a total of 8 PH patients (10 lesions) diagnosed pathologically in Yueqing People′s Hospital were collected. The location, size, and shape of the lesions, as well as the CT (4 patients with 4 lesions) and MRI (5 patients with 7 lesions) characteristics of the patients were analyzed. Descriptive method was used for statistical analysis.Results:Among the 8 PH patients, 6 patients had lesions located in the right lobe of the liver, 1 in the left lobe of the liver, and 1 (3 lesions) in both left and right lobes of the liver. Eight lesions were round or round-like, and 2 lesions were irregularly shaped. The median maximum diameter of the lesions was 4.2 cm (ranged from 2.2 to 9.3 cm), of which the maximum diameters of 2 lesions were less than 3.0 cm, those of 6 lesions were 3.1 to 5.0 cm, and those of 2 lesions were more than 6.0 cm. Nine lesions had clear boundaries, and 1 lesion had blurred boundary; 9 lesions had capsule, 1 lesion had no capsule; 1 lesion had blood vessels passing through it. The CT plain scan of 4 patients (4 lesions) showed that 3 lesions had uniform density and 3 lesions had low density, the CT enhancement showed that 2 lesions were significantly enhanced in the arterial phase, 3 lesions were sustained moderately enhanced in the portal phase, and 2 lesions were sustained mildly enhanced in the delayed phase. The MRI plain scan of 5 patients (7 lesions) showed uniform signals in 6 lesions, low signal in 3 lesions and equal signal in 4 lesions on T1-weighted images, high signal in 6 lesions on T2-weighted images, high signal in 3 lesions and equal signal in 4 lesions on diffusion-weighted images. The MRI enhancement showed that 4 lesions were significantly enhanced in the arterial phase, 5 lesions were sustained moderately enhanced in the portal phase, and 6 lesions showed sustained mild enhanced in the delayed phase.Conclusion:The PH lesions are round or round-like, with clear or unclear boundaries and uniform or uneven density, and are characterised by low density on CT and MRI plain scan, low signal on T1-weighted images, and high signal on T2-weighted images and diffusion-weighted images, and moderate or significant sustained enhancement on CT and MRI enhancement.

Objective:To study the CT manifestations of malignant hepatic perivascular epithelioid cell carcinoma (PEComa).Methods:Clinical data of nine patients undergoing surgery with histologically confirmed malignant hepatic PEComa in Yueqing People's Hospital, Wenzhou People's Hospital, and Yongjia County People's Hospital from January, 2010 to June, 2022 were retrospectively collected, including two males and seven females with a median age of 47 (43, 56) years old. The CT findings, including tumor size, shape, boundary, density, and enhancement patterns, were analyzed.Results:CT scans showed that all nine tumors were single lesions. Five tumors were located in right liver lobe, three in left lobe, and one in caudate lobe. The median tumor diameter was 5.7 (range, 3.3-16.0 ) cm. In terms of tumor shape, three were round, four were quasi-circular, and two were irregular. Eight tumors had well-defined boundaries, while one was ill-defined. Nine tumors showed uneven densities and were lower than the adjacent liver parenchyma. Four tumors had a false capsule, one contained fatty tissue, and six had necrotic and cystic changes. In the arterial phase of contrast-enhanced CT scanning, two tumors showed moderate enhancement and seven showed significant enhancement. In the portal venous and delayed phases, enhancement decreased significantly in four cases, showing a " fast-in and fast-out" pattern. In four cases, the enhancement persisted, showing a " fast-in and slow-out" pattern. One case showed no enhancement in any phase but had a strip-like enhanced vessel inside the tumor. Five cases had significantly thickened vessels around the tumor.Conclusion:The CT manifestations of PEComa are as follows: round or quasi-circular lesions with well-defined boundaries, uneven low densities, significant enhancement in the arterial phase and rapid washout or persistent enhancement in the portal venous and delayed phases.

Objective:To explore the CT features of inflammatory pseudotumor like follicular dendritic cell sarcoma (FDCS) of the spleen.Methods:The clinical data of 12 patients with splenic inflammatory pseudotumor like FDCS admitted to 3 central hospitals including Yongjia People's Hospital in Zhejiang Province from January 2015 to December 2022 were retrospectively analyzed, including 4 males and 8 females, with a median age of 60 years old. The number, shape, size and CT features of the lesions were analyzed based on patient's CT image data.Results:CT scans of 12 patients showed 15 lesions, including 10 single lesions and 2 multiple lesions. The lesions were circular in 5 cases, elliptical in 4 cases, and irregular in 3 cases. The median maximum diameter of the mass is 6.5 cm. On plain scan, all 12 tumors showed low density or slightly low density. The CT value is (41.3±7.2) HU; 8 cases had uneven density and 4 cases had uniform density. There were 8 cases with clear tumor boundaries and 4 cases with unclear boundaries. There were 8 cases with tumor necrosis and cystic transformation, and 5 cases showed patchy bleeding lesions in the center of the tumor. Enhancement: the arterial phase shows small patches or flocculent enhancement at the edges or parenchymal parts of the tumor, with CT value of (56.0±3.8) HU. Among them, there were 7 cases of mild enhancement, 4 cases of moderate enhancement, and 1 case of significant enhancement. During the portal phase, there was mild to moderate persistent small patchy uneven enhancement, with CT value of (62.0±4.3) HU. Among them, there were 8 cases of mild enhancement and 4 cases of moderate enhancement. The delayed phase showed a slow withdrawal of enhancement, with CT value of (45.0±8.2) HU. All 12 cases underwent complete resection and were diagnosed with FDCS through pathological examination.Conclusion:FDCS plain scan shows circular or elliptical uneven low-density masses, with small patches or flocculent light to moderate uneven enhancement in the arterial phase, continuous enhancement in the portal phase, and slow withdrawal in the delayed phase as the main characteristics.

Objective:To investigate the magnetic resonance imaging (MRI) features of desmoplastic small round cell tumor (DSRCT) of the abdomen and pelvis.Method:The retrospec-tive and descriptive study was conducted. The clinicopathological data of 8 patients with DSRCT of the abdomen and pelvis, including 3 cases admitted in Yueqing People's Hospital and 5 cases admitted in Wenzhou People's Hospital, from January 2008 to June 2022 were collected. There were 5 males and 3 females, aged (43±5)years. All patients underwent MRI plain and enhanced scanning. Observa-tion indicators: (1) imaging features of DSRCT of the abdomen and pelvis; (2) treatment and pathological examination characteristics of DSRCT of the abdomen and pelvis; (3) follow-up. Measurement data with normal distribution were represented as Mean± SD, and measurement data with skewed distri-bution were represented as M(range). Count data were described as absolute numbers. Results:(1) Imaging features of DSRCT of the abdomen and pelvis. ① Tumor location. Of the 8 patients, there were 6 cases with tumors located respectively at the lower edge of the liver in the right quarter costal region, the medial side of the ileocecal region in the right iliac region, the medial side of the caecum in the right iliac region, the gastro-pancreatic space in the left quarter costal region, the mesenteric space in the left iliac region and the right side of pelvic bladder, and 2 cases with tumors located at retroperitoneal space of left quarter rib region. ② Tumor size. There were 13 lesions in the 8 patients, and the maximum diameter of tumor was 9.1 (range, 3.5?20.0)cm. Of the 8 patients, there were 5 cases with single tumor and 3 cases with multiple tumors. ③ Tumor shape and boundary. Of the 8 patients, there were 4 cases with tumor in expansive growth and 4 cases with tumor in invasive growth. There were 5 cases with tumor of intratumoral necrosis and cystic degene-ration, 4 cases with tumor of intratumoral hemorrhage, 4 cases with tumor of intratumoral spot calcification, 3 cases with tumor of peritumoral tissue exudation. One patient may combined with multiple imaging manifestations. ④ Imaging characteristics of MRI plain scanning. Of the 8 patients, there were 4 cases with tumor of homogeneous hypointensity signal and 4 cases with tumor of hypointensity mixed with speckled hyperintensity (with hemorrhage) in T1 weighted imaging of MRI plain scanning. There were 3 cases with tumor of homogeneous hyperintensity and 5 cases with tumor of high signal at the edge, patchy and spot-shaped in the center in T2 weighted imaging of MRI plain scanning. There were 5 cases with tumor of high, equal and low confounding signals and 3 cases with tumor of high and low signals in T2 weighted imaging fat suppression sequence of MRI plain scanning. There were 3 cases with tumor of uniform high signals and 5 cases with tumor of high, equal and low mixed signals in diffusion weighted imaging of MRI plain scanning. ⑤ Imaging characteristics of MRI enhanced scanning. All 8 patients had tumor of heterogeneous enhancement in MRI enhanced scanning, including 2 cases with significant enhancement in arterial phase, continuous enhancement in portal phase, slightly reduced enhancement in delayed phase, 4 cases with moderate enhancement in arterial phase, continuous enhancement in portal phase, slowly exited enhancement in delayed phase, 2 cases with mild enhancement in arterial phase, continuous enhancement in portal phase, slowly exited enhancement in delayed phase. Of the 8 patients, there were 3 cases with tumor of annular enhancement with intratumoral strip or grid signals and 3 cases with tumor of peritumoral blood vessels increased and thickened signals. ⑥ Tumor invasion and metastasis. Of the 8 patients, there were 4 cases with tumor invaded bowel, 2 cases with tumor invaded surrounding tissues, 1 case with tumor invaded left kidney, spleen and pancreatic tail, 1 case with tumor invaded distal of left ureter. There were 5 cases with abdominal, retroperitoneal and inguinal lymph nodes enlargement, 4 cases with multiple nodular thickening of peritoneum and ascites, 2 cases with tumor liver and lung metastasis and 1 case with tumor rib, femur and sacrum metastasis. One patient may combined with multiple tumor metastasis. (2) Treatment and patholo-gical examination characteristics of DSRCT of the abdomen and pelvis. Of the 8 patients, 3 patients underwent complete resection as clear tumor boundary, 3 patients underwent tumor partial resection as tight adhesion between tumor and surrounding blood vessels, 2 cases underwent tumor tissue pathological examination as extensive metastasis of peritoneum, omentum, mesentery and surrounding intestine. All 8 patients were diagnosed as DSRCT by microscopic examination, electron microscopic examination, immunohistochemical staining and cytogenetic examination. (3) Follow-up. All 8 patients underwent postoperative follow-up and died during the follow-up.Conclusion:MRI features of abdominal and pelvic DSRCT include single or multiple lobulated masses with unclear boundaries, invading the omentum, mesentery, peritoneum and adjacent tissues in most cases, mixed signals and heterogeneous mild to moderate enhancement in enhanced scanning.

Objective:To explore the imaging features of hyperostosis frontalis interna (HFI).Methods:One hundred patients with clinically diagnosed HFI were enrolled from Department of Radiology, Yueqing People's Hospital and Department of Imaging, Wenzhou People's Hospital from January 2011 to December 2022. MRI alone was performed in 45 patients; MRI+DR was performed in 14, and MRI+CT was performed in 41. The imaging features of these patients were analyzed retrospectively.Results:In these 100 patients, 20 were with external hyperplasia, 51 with internal hyperplasia, and 29 with intermediate hyperplasia. External hyperplasia manifested as proliferating towards the diploe, enjoying clear boundary, uniform high signals of the hyperplastic inner plate and diploe on T1WI and T2WI, and high density of the hyperplastic inner plate and diploe on CT and DR. Internal hyperplasia manifested as proliferating towards the cranial cavity, enjoying wavy or nodular inner edges, non-uniform low signals of hyperplastic inner plate on T1WI and T2WI, and high density of the hyperplastic inner plate on CT and DR. Intermediate hyperplasia manifested as proliferating simultaneously towards the cranial cavity and diploe, enjoying thin and blurred diploe, uniform or non-uniform high signals of the hyperplastic inner plate and diploe on T1WI and T2WI, and non-uniform high density of the hyperplastic inner plate and diploe on CT and DR. Compressed and displaced brain parenchyma, reduced anterior cranial fossa volume, and narrowed subarachnoid space were noted in these 100 patients, including 47 patients with obvious frontal lobe brain tissue compression (depth of 3.0-17 mm, averaged [8.6±5.9] mm), 35 with lacunar cerebral infarction, 33 with subcortical arteriosclerotic encephalopathy, and 32 with varied degrees of cerebral atrophy.Conclusion:HFI is characterized by thickening and hardening of the bilateral frontal bone inner plates, with wavy, nodular or spindle-shaped inner edges, compressed brain tissues, and reduced anterior cranial fossa; these imaging features can help the definite diagnosis of HFI.

The patient, a 61-year-old female, was admitted to the hospital for 15 days of frequent urination, urgency, painful urination and hematuria. B-ultrasound showed irregular hypoechoic masses on the anterior wall of the bladder. CT showed that the right anterior wall of the bladder protruded into the cavity of the soft tissue mass, which was lobulated, and the edge of the mass showed arc-shaped calcification; enhancement shows that the mass continues to enhance. Cystoscopy showed a lobulated soft tissue mass protruding into the cavity on the right anterior wall of the bladder, and cystoscopy showed tumor-like lesions. The preoperative clinical and imaging diagnosis was a malignant tumor of the bladder. Open partial resection of the right anterior wall of the bladder under general anesthesia, and pathological diagnosis of bladder leiomyosarcoma after surgery. Adjuvant chemotherapy (gemcitabine 1.6 g + epirubicin 80 mg + cisplatin 30 mg) was started 2 months after the operation. The chemotherapy was discontinued after a year, and the patient had no obvious adverse reactions. There were no signs of recurrence and metastasis after a 2-year follow-up.