Ureteral dilatation detected in magnetic resonance imaging predicts vesicoureteral reflux in children with urinary tract infection.

OBJECTIVE: Urinary tract infection (UTI), one of the most common bacterial infections occurring during infancy and early childhood, is frequently associated with vesicoureteral reflux (VUR). Although several guidelines recommend performing ultrasonography as a screening test, its utility is not adequate and appropriate screening tests are strongly desirable. In this study, we evaluate the use of magnetic resonance imaging (MRI) as a screening test for VUR in children with UTI. METHODS: We prospectively studied 108 patients with suspected UTI between April 2014 and March 2016. UTI was diagnosed on the basis of diffusion-weighted MRI (DW-MRI) and urine culture findings. We measured ureteral dilatation using MRI in 96 patients with UTI and assessed the relationship between ureteral dilatation in MRI and VUR in 46 patients who underwent voiding cystourethrography (VCUG). RESULTS: Among 108 patients, 88 and 8 were diagnosed with upper and lower UTI, respectively. Among 46 patients who underwent VCUG, 23 had VUR (14 low grade and 9 high grade). Patients with ureteral dilatation detected on MRI had VUR more frequently than those without ureteral dilatation (any grades VUR, 71% vs. 32%; P = 0.02; high-grade VUR, 38% vs. 2%, P = 0.007). Overall, ureteral dilatation findings on MRI achieved sensitivity 65.2% and specificity 73.9% as a screening test for VUR. In addition, DW-MRI achieved sensitivity 100% and specificity 81.8% in the diagnosis of upper UTI. CONCLUSION: These findings suggested that MRI is a valuable tool for screening of VUR as well as diagnosis of upper UTI.

A predictive diagnostic model using multiparametric MRI for differentiating uterine carcinosarcoma from carcinoma of the uterine corpus.

PURPOSE: To construct a diagnostic model for differentiating carcinosarcoma from carcinoma of the uterus. MATERIALS AND METHODS: Twenty-six patients with carcinosarcomas and 26 with uterine corpus carcinomas constituted a derivation cohort. The following nine MRI features of the tumors were evaluated: inhomogeneity, predominant signal intensity, presence of hyper- and hypointense areas, conspicuity of tumor margin, cervical canal extension on T2WI, presence of hyperintense areas on T1WI, contrast defect area volume percentage, and degree of enhancement. Two predictive models-with and without contrast-were constructed using multivariate logistic regression analysis. Fifteen other patients with carcinosarcomas and 30 patients with carcinomas constituted a validation cohort. The sensitivity and specificity of each model for the validation cohort were calculated. RESULTS: Inhomogeneity, predominant signal intensity on T2WI, and presence of hyperintense areas on T1WI were significant predictors in the unenhanced-MRI-based model. Presence of hyperintensity on T1WI, contrast defect area volume percentage, and degree of enhancement were significant predictors in the enhanced-MRI-based model. The sensitivity/specificity of unenhanced MRI were 87/73 and 87/70% according to reviewer 1 and 2, respectively. The sensitivity/specificity of the enhanced-MRI-based model were 87/70% according to both reviewers. CONCLUSIONS: Our diagnostic models can differentiate carcinosarcoma from carcinoma of the uterus with high sensitivity and moderate specificity.

[Malignant lymphoma in a perineural spreading along trigeminal nerve, which developed as trigeminal neuralgia].

A rare cause of trigeminal neuralgia is malignant lymphoma which spread along the trigeminal nerve. We report a 79-year-old male presented with 4-month history of neuralgic pain in right cheek. He was diagnosed as classical trigeminal neuralgia. It had improved through medication of carbamazepine. Four months later, the dull pain unlike neuralgia complicated on the right cheeks, it was ineffective with the medication. Furthermore, diplopia and facial palsy as the other cranial nerve symptoms appeared. Gadolinium-enhanced magnetic resonance imaging (MRI) revealed contrast-enhanced mass lesion extend both external pterygoid muscle and brainstem through the swelling trigeminal nerve. The patient was pathological diagnosed of diffuse large B cell lymphoma by biopsy. Malignant lymphoma should be considered in the different diagnosis of cases with a minimal single cranial nerve symptom.

Dual-energy CT can evaluate both hilar and mediastinal lymph nodes and lesion vascularity with a single scan at 60 seconds after contrast medium injection.

RATIONALE AND OBJECTIVES: The aim of this study was to investigate whether 80-kVp and weighted-average 120-kVp computed tomographic (CT) images scanned at 60 seconds after contrast material injection using a dual-source CT scanner could substitute for conventional 120-kVp images obtained at 30 and 100 seconds. MATERIALS AND METHODS: Eighty-three consecutive patients with suspected lung cancer were enrolled. Images were obtained in dual-energy mode (80 and 140 kVp) at 60 seconds and conventional 120-kVp mode at 30 and 100 seconds after contrast injection. The CT numbers of the pulmonary artery, pulmonary vein, hilar zone lymph nodes, and pulmonary lesions were measured. Contrasts between the pulmonary artery/pulmonary vein and lymph nodes and beam-hardening artifacts were visually evaluated using five-point and four-point scales, respectively. The degree of enhancement was evaluated on 30-second 120-kVp, 100-second 120-kVp, and 60-second weighted-average 120-kVp images. RESULTS: The mean differences in attenuation between the pulmonary artery/pulmonary vein and lymph nodes on the 30-second 120-kVp, 60-second 80-kVp, and 60-second weighted-average 120-kVp images were 184/155, 130/140, and 84/92 Hounsfield units, respectively (all P values <.001). The mean contrast scores for the hilar/mediastinal lymph nodes were 4.5/4.7, 3.7/4.2, 3.3/3.6, and 2.4/2.5 for these three and for 100-second 120-kVp images, respectively (all P values <.01). The mean artifact scores of the four images were 1.2, 3.4, 3.6, and 4.0, respectively. On 60-second weighted-average 120-kVp images, 55 of 60 lesions (92%) showed higher enhancement than on 100-second conventional 120-kVp images. CONCLUSIONS: Dual-energy CT images scanned 60 seconds after contrast injection show excellent vessel-lymph node contrast and enhancement of lesions and can replace dual-phase scan protocols.

Usefulness of dual-energy CT scanning at 80 kVp for identifying hilar and mediastinal structures: evaluation of contrast enhancement of the pulmonary vessels and lymph nodes.

PURPOSE: We examined whether the 80-kVp CT images scanned at 100 s after contrast material injection using a dual-source scanner could be substituted for the conventional 120-kVp images obtained at an earlier timing of 30 s. MATERIALS AND METHODS: Seventy-eight patients with suspected lung cancer were examined with a 120-kVp mode at 30 s after contrast material injection (early phase) and a dual-energy (80 and 140 kVp) mode at 100 s (late phase). CT numbers of the pulmonary artery (PA), pulmonary vein (PV) and hilar zone lymph nodes (LN) were measured. Contrast between the PA/PV and LN was visually evaluated using a 5-point scale. Beam-hardening artifacts were also visually assessed. RESULTS: The mean difference in attenuation between the PA/PV and LN on the early phase 120-kVp, late phase 80-kVp and late phase weighted-average 120-kVp images was 171.3/160.8, 100.5/106.8 and 67.5/67.5, respectively (p < 0.001). The mean contrast score of these three images for the hilar/mediastinal LN was 4.5/4.7, 3.4/3.8 and 2.9/3.3, respectively (all p < 0.05). The mean artifact score of the three images was 2.6, 4.0 and 4.0, respectively; on most early phase images, the beam-hardening artifacts influenced the diagnosis (p < 0.001). CONCLUSION: The late phase 80-kVp images showing few artifacts may be an alternative to early phase 120-kVp images.

Can dual-energy CT evaluate contrast enhancement of ground-glass attenuation? Phantom and preliminary clinical studies.

RATIONALE AND OBJECTIVES: Evaluation of contrast enhancement of pulmonary lesions with ground-glass attenuation (GGA) is difficult with conventional techniques but might be possible using contrast-mapping images (CMIs) obtained by dual-energy computed tomography. To address this issue, a phantom study was conducted, and this technique was then applied to clinical cases. MATERIALS AND METHODS: Phantoms made of agarose gel and those made of hollow resin clay, containing various concentrations of iodine or calcium, were used to simulate soft tissue and GGA, respectively. They were scanned using a dual-energy computed tomographic scanner, and the relationship between iodine concentration and calculated iodine value on CMIs was examined. The influence of calcium was also evaluated. In addition, contrast enhancement of 24 GGA lesions was evaluated on CMIs. RESULTS: There was a good correlation between iodine value and iodine concentration in the soft-tissue models (r(2) = 0.996). In the GGA models, the former tended to exceed the latter when default parameters for calculating CMIs were used, but this could be corrected by modifying the parameters (r(2) = 0.998). The iodine value increased with calcium concentration in both models. On CMIs, contrast enhancement was visible in 22 adenocarcinomas but not in a pulmonary hemorrhage and an inflammatory change. CONCLUSIONS: Dual-energy computed tomography can evaluate contrast enhancement of GGA lesions.

Pulmonary manifestations in Sjogren's syndrome: correlation analysis between chest computed tomographic findings and clinical subsets with poor prognosis in 80 patients.

OBJECTIVE: Sjögren's syndrome (SS) has a varied clinical spectrum and has been associated with various chest computed tomography (CT) findings. We sought to delineate the characteristic CT features in various subsets of SS, especially poor prognosis subsets. METHODS: Retrospectively identified 80 never-smoker SS patients [56 primary SS (1-SS), 24 secondary SS (2-SS)] who underwent chest CT at our institution during a 3-year period from 2004 through 2007 were included in this study. Chest CT findings were qualitatively and semiquantitatively analyzed with comparison between 1-SS and 2-SS, and correlation with anti-SSB/La seropositivity and the presence of clonally derived lymphoproliferative disorder (cLPD), which are known to be pathognomonic and prognostic clinical features of SS patients. RESULTS: All patients were women with median age of 60 years. Anti-SSB/La antibodies were found in 17 primary SS patients and 4 2-SS patients. Eleven patients with cLPD were identified and all of them had 1-SS. The most frequent CT finding in both types of patients was interlobular septal thickening. Secondary SS was associated with a significantly greater frequency and extent of honeycombing versus 1-SS. Univariate and multivariate analysis showed a significant association between honeycombing and 2-SS. In patients with 1-SS and in the SS group as a whole, we observed independent and significant associations between cysts and anti-SSB/La seropositivity or cLPD. CONCLUSION: Cysts are significantly associated with anti-SSB/La seropositivity and cLPD. The presence of lung cysts revealed by chest CT might be a prognostic clinical feature, a clue, or a predictor of cLPD in patients with SS.