Staging Liver Fibrosis: Comparison of Native T1 Mapping, T2 Mapping, and T1ρ: An Experimental Study in Rats With Bile Duct Ligation and Carbon Tetrachloride at 11.7 T MRI.

BACKGROUND: T1, T2, and T1ρ might be potential biomarkers for assessing liver fibrosis. However, few studies reported the value of them in different animal models. PURPOSE: To investigate and compare the performances of T1, T2, and T1ρ for noninvasively staging liver fibrosis in bile duct ligation (BDL) or carbon tetrachloride (CCl4 ) model. STUDY TYPE: Prospective animal model. SUBJECTS: Liver fibrosis was induced by BDL or injection of CCl4 in 120 rats. FIELD STRENGTH/SEQUENCE: 11.7 T, T1 mapping with 10 repetition times, T2 mapping with 32 echo times, and T1ρ with 10 spin-lock times. ASSESSMENT: T1, T2, and T1ρ were measured and correlated with liver fibrosis stages, as well as the degree of inflammation, steatosis, iron deposition, and the expression of cytokeratin 19. The discriminative performance of T1, T2, and T1ρ for staging liver fibrosis was compared. STATISTICAL TESTS: One-way analysis of variance (ANOVA), Spearman's correlation analysis, factorial design ANOVA, and receiver operating characteristic curves (P < 0.05 was considered statistically significant). RESULTS: T1, T2, and T1ρ (BDL: rho = 0.73, 0.85, 0.68; CCl4 : rho = 0.80, 0.29, 0.61) were significantly correlated with liver fibrosis stages, while there was no significant difference in T2 among stage F0-F4 in the CCl4 model (P = 0.204). The area under the curves (AUCs) range of T1, T2, and T1ρ for predicting ≥F1, ≥F2, ≥F3, and F4 were 0.76-0.95, 0.89-0.98, and 0.80-0.94 in the CCl4 model. For the CCl4 model, the AUCs range of T1, T2, and T1ρ for predicting ≥F1, ≥F2, ≥F3, and F4 were 0.83-0.95, 0.61-0.74, and 0.73-0.89, respectively. T2 had significantly higher AUC in the BDL model than CCl4 model for diagnosing liver fibrosis. DATA CONCLUSION: The most sensitive and accurate method for staging liver fibrosis appeared to be T1 in our animal models followed by T1ρ. T2 may not be suitable for evaluating liver fibrosis. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY STAGE: 2.

Correlative investigation between routine clinical parameters of dual-energy computed tomography and the outcomes of extracorporeal shock wave lithotripsy in children with urolithiasis: a retrospective study.

PURPOSE: To evaluate the associations of DECT parameters with extracorporeal shock wave lithotripsy (ESWL) outcomes in pediatric patients. METHODS: A retrospective study of consecutive patients with calculi who underwent ESWL and DECT in our hospital was performed in 2011-2019. The primary outcome was DECT imaging's correlation with ESWL outcomes. The secondary outcome was to determine DECT parameters independently predicting ESWL outcomes, including stone-free (SF) and residual stone (RS) statuses. RESULTS: The study included 207 patients. The mean CT attenuations at 140 kVp, 80 kVp, and 120 kVp and effective atomic number (Zeff) were significantly correlated with stone free (SF) and residual stone (RS) (P < 0.05). Areas under the curves (AUCs) of CT attenuations at 120 kVp, 80 kVp, 140 kVp, and dual-energy index (DEI) were 0.784 (95% CI 0.672-0.897), 0.780 (95% CI 0.677-0.884), 0.766 (95% CI 0.658-0.885), and 0.709 (95% CI 0.578-0.840) (all P < 0.05). With cutoffs of 882.5, 1330.5, 1042.5, and 0.103 for CT attenuations at 140 kVp, 80 kVp, 120 kVp, and DEI, respectively, sensitivities and specificities were 75.0% and 31.1%, 83.3% and 31.8%, 80.3% and 31.1%, and 58.3% and 44.7%, respectively. CONCLUSION: Our results demonstrated that the parameters of DECT could be used to predict ESWL outcomes (especially the SF status) in children with urolithiasis. ESWL success can be accurately predicted by DECT, and it is hard to predict ESWL failure.

Botryoid Wilms' tumor: report of two cases.

BACKGROUND: Botryoid Wilms' tumor is a rare kind of Wilms' tumor. We report two cases of this tumor. METHODS: Case 1, a 2-year-old boy, was admitted with macrohematuria for 5 months. Case 2, a 19-month-old boy, was referred for a palpable abdominal mass. The two cases were checked by 64-row multi-slice spiral CT (MSCT) and scanned with the dynamic contrast enhancement. The masses were excised and pathologically confirmed. RESULTS: In case 1, the mass occurred in the renal pelvis and calyx bilaterally, with heterogeneous density and prominent calcification. By contrast enhanced CT scan, the mass was mildly enhanced. In case 2, the left renal pelvis and ureter were filled with the tumor. Unenhanced scan revealed that the mass was homogeneous and non-calcified. In contrast, the mass was slightly and heterogeneously enhanced. Macroscopically, the mass filled in the pelvicalyceal system and had a botryoid appearance. Microscopically, the typical features of Wilms' tumor with blastemal, epithelial, and stromal components were evident. CONCLUSION: Botryoid Wilms' tumor should be included in the differential diagnosis of tumors in the pelvicalyceal system no matter it is unilateral or bilateral.

Arterial phase of biphase enhancement spiral CT in diagnosis of small hepatocellular carcinoma.

OBJECTIVES: To evaluate the value of the arterial Phase (AP) of biphase enhanced spiral CT (SCT) in the diagnosis of small HCC and to investigate the criteria, initial time, ending time and duration of AP. METHODS: From May 1995 to March 1999, patients with small HCC proved surgically and pathologically including 49 patients (n=53) in group A, 148 (n=186) in group B and 52 (n=52) in group C were collected. Biphase dynamic enhanced SCT scans were performed in all patients of the three groups and additional single-level dynamic scans only done in the group C. The detectability, diagnostic accuracy of lesions and enhancement of the lesions in AP were analyzed statistically. In addition, the initial time, ending time and duration of AP were measured. RESULTS: The results of the group A showed the detectability of small HCC was 88.68% in AP and 90.57% in both Phases, higher than those by ultrasound. Markedly enhanced lesions in AP accounted for 76% and 78% in the groups B and C respectively. The initial time, ending time and duration of AP measured on single-level dynamic scans were 16.9 s, 39.6 s and 22.7 s on average respectively. CONCLUSIONS: The biphase dynamic SCT especially its arterial phase appears to be very valuable in diagnosing small HCCs. In light of short duration of AP, understanding and strict control of AP is obviously imperative.