Delayed Phase Images Research Articles

Contrast-Enhanced Ultrasound of Congenital and Infantile Hemangiomas: Preliminary Results From a Case Series.

OBJECTIVE. The contrast-enhanced ultrasound (CEUS) imaging features of hepatic vascular tumors in infants, including infantile hemangioma (IH) and congenital hemangioma (CH), are not well reported. Frequent inaccurate use of lesion terminology in the literature has created diagnostic confusion. The purpose of this study is to describe the CEUS features of IH and CH. MATERIALS AND METHODS. Ten patients, ranging in age from 8 days to 16 months, with hepatic vascular tumors were included for retrospective analysis. Gray-scale ultrasound, color Doppler ultrasound, and CEUS features were reviewed, and interobserver kappa coefficients were calculated. Final diagnoses were clinically determined by a pediatrician with expertise in vascular anomalies except in one patient who underwent surgical excision. RESULTS. Of the 10 patients, five had CHs and five had IHs. All 10 lesions were hyperenhancing in the early arterial phase. In the portal venous phase, four of five (80%) CHs showed hyperenhancement relative to normal liver parenchyma, whereas four of five (80%) IHs showed isoenhancement. In the late phase, washout of contrast material was seen in three of five (60%) IHs, whereas one IH remained isoenhancing and one IH was hyperenhancing. None of the CHs showed late washout. Interobserver kappa coefficients for CEUS features ranged from 0.60 to 1.00. CONCLUSION. Except for the CEUS feature portal venous phase enhancement (κ = 0.60), good to excellent (κ = 0.74-1.00) agreement about CEUS features of IHs and CHs was observed. A significant proportion of IHs (60%) showed washout at delayed phase imaging, which has also been reported with malignancies. Recognition of the overlap in imaging appearance of these two entities is vital to preventing misdiagnosis of malignancy.

MRI diagnostic features for predicting nipple-areolar-complex involvement in breast cancer

PurposeTo evaluate magnetic resonance imaging (MRI) features including tumor-nipple enhancement for predicting nipple-areolar-complex (NAC) involvement in breast cancer. MethodsA total of 249 breast cancer cases with available preoperative MRI data were studied. On MRI, tumor-nipple enhancement was evaluated 2 min (early) and 6 min (delayed) after contrast injection. Asymmetric nipple enhancement, mass size, tumor-nipple distance, presence of nipple discharge, and enhancement type (mass or non-mass enhancement) were evaluated. ResultsOf the 249 breast cancers, 24 (9.6%) showed NAC involvement. Early tumor-nipple enhancement was found in 37 (14.9%) cancers and delayed tumor-nipple enhancement in 12 (4.8%) cancers. On comparing early and delayed enhancement, 43.2% (16/37) of early tumor-nipple enhancements showed NAC involvement while 25.0% (3/12) of delayed tumor-nipple enhancements showed NAC involvement (P = 0.323). On multivariate analysis, tumor-nipple enhancement (P = 0.004) and tumor-nipple distance with 2 cm cut-off (P = 0.044) were significant. The area under the receiver-operating-characteristic curve (AUC) of early tumor-nipple enhancement was significantly higher (0.787) than that of delayed tumor-nipple enhancement (0.542, P = 0.001). The AUC was the highest when any kind of tumor-nipple enhancement was combined with a tumor-nipple distance of 1 cm (0.878). ConclusionsTumor-nipple enhancement and tumor-nipple distance on MRI could predict NAC involvement in breast cancer. When enhancement was evaluated on both early and delayed phase images with a combined tumor-nipple distance of ≤1 cm, the prediction of NAC involvement showed the best performance.

MRI presentation of hepatocellular carcinoma in non-alcoholic steatohepatitis (NASH)

PurposeTo describe the magnetic resonance imaging (MRI) features of hepatocellular carcinoma (HCC) in patients with non-alcoholic steatohepatitis (NASH). MethodsMRI examinations of 21 patients with HCC and NASH were analyzed by two observers. There were 18 men and 3 women with a mean age of 67.9 ± 10.2 (SD) years (range: 36–85 years). Images were qualitatively and quantitatively analyzed with respect to imaging presentation. ResultsHCC presented as a single tumor in 13/21 patients (62%), with a mean longest diameter of 26.9 ± 20.2 (SD) mm (range: 12–88 mm); 17/30 HCC (57%) had a largest diameter <20 mm. A signal drop between in- and out-of-phase T1-weighted MR images was observed in 16/30 HCC nodules (53%). All HCC nodules (30/30; 100%) showed hyperenhancement on arterial phase images and 12/30 HCC nodules (40%) did not show a wash-out on portal or delayed phase images. Encapsulation was observed in 18/30 HCC nodules (60%). MRI findings consistent with liver cirrhosis were present in 16/21 patients (76%). ConclusionsOur results show that 57% of HCC in NASH can present as a lesion smaller than 20 mm and 40% do not display wash-out. These results suggest that classical imaging criteria developed for noninvasive diagnosis of HCC should be applied with caution to HCC in patients with NASH.

Visibility of the hilar lymph nodes using advanced virtual monoenergetic low-keV images for preoperative evaluation of lung cancer

The purpose of our study was to evaluate the visibility of the hilar lymph nodes (LNs) using advanced virtual monoenergetic low-keV images compared with early-phase contrast-enhanced CT. Dual energy contrast-enhanced CT was performed for pre-operative evaluation of lung cancer at 20 and 60 s after administration of contrast media in 50 patients (32 males and 18 females; mean age, 69 years). Five kinds of images (A: 20 s/120 kV; B: 60 s/40 keV; C: 60 s/50 keV; D: 60 s/120 kV; E: 60 s/100 kV) were reconstructed. We measured the CT number of the bilateral main pulmonary arteries (PAs), pulmonary veins (PVs) and hilar LNs, and evaluated the differences in CT number (Hounsfield units, HUs) between the PA/PV and LNs (PA-LN and PV-LN contrast). Artifacts from the superior vena cava (SVC) were also evaluated. The mean PA-LN contrast (HU) was 415 in image group A, 299 in B, 180 in C, 80 in D, and 100 in E. The mean PV-LN contrasts in each group were 306, 287, 177, 78, and 99, respectively. Image group B showed the second highest PA-LN contrast following image group A. There was no significant difference in the PV-LN contrast between image groups A and B. The PA-LN and PV-LN contrasts of image groups B and C were significantly higher than those of E. SVC artifacts were lower in the delayed-phase images (Group B-E) than in Group A. To evaluate the hilar LNs with a single image series, advanced virtual monoenergetic 40-keV imaging at the delayed 60-s phase seems to be the most valuable. Advanced virtual monoenergetic image is useful for evaluation of both hilar LNs and tumors in the delayed phase without artifact derived from the streak artifact from dense contrast media in the SVC.

Breast MRI in the era of diffusion weighted imaging: do we still need signal-intensity time curves?

ObjectiveDynamic contrast-enhanced imaging of the initial (IP) and delayed phase (DP) is an integral part of any clinical breast MRI protocol. Furthermore, DWI is increasingly used as an add-on sequence by the breast-imaging community. We investigated whether DWI could be used as a substitute DP.Material and methodsOne hundred thirty-two consecutive patients with equivocal or suspicious findings at ultrasound and/or mammography received a full diagnostic breast MRI according to international recommendations. Histopathological verification served as reference standard. We evaluated three sections of the MRI protocol: IP, DP, and apparent diffusion coefficient (ADC) maps derived from DWI. Circular ROIs (regions of interest, mean size 5–10 mm2) were drawn into the enhancing parts of the lesion (first postcontrast). ROIs were transferred to the corresponding location on ADC maps and IP and DP images. Mean ROI values were investigated signal intensity (SI): (1) Initial-phase enhancement = (SI(IP) − SI(precontrast))/SI(precontrast); (2) Delayed-phase enhancement = (SI(DP) − SI(IP))/SI(IP); (3) ADC. Multiparametric combinations were computed using logistic regression analysis: (1) IP+: Initial-phase enhancement and ADC; (2) Curve: Initial-phase enhancement and delayed-phase enhancement; (3) Curve+: Curve and ADC. The diagnostic performances of these feature combinations to diagnose malignancy were compared by the area under the receiver-operating characteristics curve (AUC).ResultsOne hundred thirty-two patients (age: mean = 57.1 years, range 23–83 years) with 145 lesions were included (malignant/benign 101/44). IP+ (AUC = 0.877) outperformed Curve (AUC = 0.788, p = 0.03). Curve+ was not superior to IP+ (p = 1).ConclusionDWI could substitute DP. Because DWI is typically used as an add-on to IP and DP, our results might help to abbreviate and to simplify current practice of breast MRI.Key Points• DWI provides similar but superior diagnostic information for diagnosis of malignancy in enhancing breast lesions compared to DP.• Adding DP to DWI does not provide incremental information to distinguish benign from malignant lesions.• DWI could substitute DP. As DWI is typically used as an add-on to IP and DP, our findings might help to abbreviate and to simplify current breast MRI practice.

Identification of Axillary Lymph Node Metastasis in Patients With Breast Cancer Using Dual-Phase FDG PET/CT

OBJECTIVE. The aim of this study was to assess the diagnostic performance of dual-phase 18F-FDG PET/CT in detecting axillary lymph node metastasis in patients with breast cancer. MATERIALS AND METHODS. A total of 826 patients with breast cancer were retrospectively evaluated. PET/CT scans were performed 1 hour and 2 hours after FDG administration before treatment. The maximum standardized uptake value (SUVmax) in the axillary lymph node at both time points (hereafter referred to as SUVmax1 and SUVmax2, respectively) and the retention index (RI) were calculated. RESULTS. Axillary lymph node metastasis was detected in 285 of 826 patients (34.5%). The median axillary SUVmax1, SUVmax2, and RI in patients with nodal metastasis were higher than those in patients without metastasis (1.5 vs 0.6, 1.6 vs 0.5, and 7.7 vs -3.7, respectively; all p < 0.001). The diagnostic accuracy of axillary SUVmax1 and SUVmax2 was equivalent, and the sensitivity and specificity of SUVmax1 were 74.7% and 83.4%, respectively. Although the performance of the axillary RI was inferior to that of SUVmax1 and SUVmax2, both the SUVmax and the RI were independent predictors of nodal metastasis, and a positive RI suggested axillary lymph node involvement when the SUVmax1 was significantly high. Of 533 patients with category T1-2 breast cancer without lymph node swelling, 101 (19.0%) had pathologic lymph node involvement; the negative predictive value of axillary SUVmax1 was 86.8%. CONCLUSION. Delayed phase imaging identified axillary lymph node metastasis as accurately as standard PET/CT. A high negative predictive value of PET/CT for the detection of nodal metastasis is helpful to avoid surgical axillary assessment in patients with category T1-2 breast cancer without lymph node swelling.

Prediction for early recurrence of intrahepatic mass-forming cholangiocarcinoma: quantitative magnetic resonance imaging combined with prognostic immunohistochemical markers

BackgroundPartial hepatectomy is the first option for intrahepatic mass-forming cholangiocarcinoma (IMCC) treatment, which would prolong survival. The main reason for the poor outcome after curative resection is the high incidence of early recurrence (ER). The aim of this study was to investigate the combined predictive performance of qualitative and quantitative magnetic resonance imaging (MRI) features and prognostic immunohistochemical markers for the ER of IMCC.MethodsForty-seven patients with pathologically proven IMCC were enrolled in this retrospective study. Preoperative contrast-enhanced MRI and post-operative immunohistochemical staining of epidermal growth factor receptors (EGFR), vascular endothelial growth factor receptor (VEGFR), P53 and Ki67 were performed. Univariate analysis identified clinic-radiologic and pathological risk factors of ER. Radiomics analysis was performed based on four MRI sequences including fat suppression T2-weighted imaging (T2WI/FS), arterial phase (AP), portal venous phase (PVP), and delayed phase (DP) contrast enhanced imaging. A clinicoradiologic-pathological (CRP) model, radiomics model, and combined model were developed. And ROC curves were used to explore their predictive performance for ER stratification.ResultsEnhancement patterns and VEGFR showed significant differences between the ER group and non-ER group (P = 0.001 and 0.034, respectively). The radiomics model based on AP, PVP and DP images presented superior AUC (0.889, 95% confidence interval (CI): 0.783–0.996) among seven radiomics models with a sensitivity of 0.938 and specificity of 0.839. The combined model, containing enhancement patterns, VEGFR and radiomics features, showed a preferable ER predictive performance compared to the radiomics model or CRP model alone, with AUC, sensitivity and specificity of 0.949, 0.875 and 0.774, respectively.ConclusionsThe combined model was the superior predictive model of ER. Combining qualitative and quantitative MRI features and VEGFR enables ER prediction, thus facilitating personalized treatment for patients with IMCC.

Dynamic contrast-enhanced computed tomography diagnosis of primary liver cancers using transfer learning of pretrained convolutional neural networks: Is registration of multiphasic images necessary?

To evaluate the effect of image registration on the diagnostic performance of transfer learning (TL) using pretrained convolutional neural networks (CNNs) and three-phasic dynamic contrast-enhanced computed tomography (DCE-CT) for primary liver cancers. We retrospectively evaluated 215 consecutive patients with histologically proven primary liver cancers, including six early, 58 well-differentiated, 109 moderately differentiated, 29 poorly differentiated hepatocellular carcinomas (HCCs), and 13 non-HCC malignant lesions containing cholangiocellular components. We performed TL using various pretrained CNNs and preoperative three-phasic DCE-CT images. Three-phasic DCE-CT images were manually registered to correct respiratory motion. The registered DCE-CT images were then assigned to the three color channels of an input image for TL: pre-contrast, early phase, and delayed phase images for the blue, red, and green channels, respectively. To evaluate the effects of image registration, the registered input image was intentionally misaligned in the three color channels by pixel shifts, rotations, and skews with various degrees. The diagnostic performances (DP) of the pretrained CNNs after TL in the test set were compared by three general radiologists (GRs) and two experienced abdominal radiologists (ARs). The effects of misalignment in the input image and the type of pretrained CNN on the DP were statistically evaluated. The mean DPs for histological subtype classification and differentiation in primary malignant liver tumors on DCE-CT for GR and AR were 39.1%, and 47.9%, respectively. The highest mean DPs for CNNs after TL with pixel shifts, rotations, and skew misalignments were 44.1%, 44.2%, and 43.7%, respectively. Two-way analysis of variance revealed that the DP is significantly affected by the type of pretrained CNN (P = 0.0001), but not by misalignments in input images other than skew deformations. TL using pretrained CNNs is robust against misregistration of multiphasic images and comparable to experienced ARs in classifying primary liver cancers using three-phasic DCE-CT.

Barker-coded modulation laser thermography for CFRP laminates delamination detection

A Barker-coded modulation thermal-wave imaging (BCTWI) with laser as an external stimulus source based on pulse compression technique is reported on carbon fiber reinforced polymer (CFRP) laminates delamination detection. CFRP samples with different size and depth flat bottom holes (FBHs) are prepared for providing simulated defects of CFRP interlayer delamination. Three kinds of thermal wave feature images (phase, delay time and peak) are formed and deeply studied on their capability of detectivity. Experimental results indicate that delay time and phase images are relatively suitable modality for low-power active thermography requirement due to insensitive to the various excitation power. BCTWI significantly improve SNR and defect depth resolution in comparison with linear frequency modulation thermography (LFMT).

Contrast Enhancement Boost Technique at Aortic Computed Tomography Angiography: Added Value for the Evaluation of Type II Endoleaks After Endovascular Aortic Aneurysm Repair

Delayed-phase acquisition of the computed tomography (CT) angiography is important for the evaluation of type II endoleaks after endovascular aortic aneurysm repair because the endoleak cavity area is associated with aneurysm sac expansion. Contrast enhancement boost (CE-boost) is a postprocessing technique for increasing the degree of contrast enhancement on contrast-enhanced CT. We aimed to investigate the usefulness of the CE-boost technique for the visualization of type II endoleaks. This retrospective study included 28 patients with type II endoleaks after endovascular aortic aneurysm repair who underwent triphasic contrast-enhanced CT. Objective (CT number, signal-to-noise ratio, and contrast-to-noise ratio) and subjective quality analyses using a four-point scale (1, poor; 4, excellent) were performed for the conventional early- and delayed-phase images as well as CE-boost delayed-phase images. The CE-boost delayed-phase images yielded a significantly higher CT number (134.5 ± 41.7 HU), signal-to-noise ratio (23.4 ± 10.5), and contrast-to-noise ratio (15.3 ± 8.4) and showed a significantly larger endoleak area (145.0 ± 134.8 mm2) than did the conventional early-phase (95.6 ± 53.2 HU, 7.3 ± 4.7, 4.0 ± 4.2, and 56.2 ± 99.3 mm2, respectively) and delayed-phase (110.5 ± 33.3 HU, 8.2 ± 2.7, 4.9 ± 2.0, and 124.8 ± 131.9 mm2, respectively) images (p < 0.01). The endoleak visibility score was highest for the CE-boost delayed-phase images (2.0 ± 1.0, 3.0 ± 0.6, and 3.4 ± 0.7 for conventional early-phase, delayed-phase, and delayed-phase CE-boost images, respectively; p < 0.001). The CE-boost technique facilitates clear visualization of type II endoleak cavities.

Atypical Appearance of Hepatocellular Carcinoma and Its Mimickers: How to Solve Challenging Cases Using Gadoxetic Acid-Enhanced Liver Magnetic Resonance Imaging.

Hepatocellular carcinoma (HCC) can be diagnosed noninvasively with contrast-enhanced dynamic computed tomography, magnetic resonance imaging, or ultrasonography on the basis of its hallmark imaging features of arterial phase hyperenhancement and washout on portal or delayed phase images. However, approximately 40% of HCCs show atypical imaging features, posing a significant diagnostic challenge for radiologists. Another challenge for radiologists in clinical practice is the presentation of many HCC mimickers such as intrahepatic cholangiocarcinoma, combined HCC-cholangiocarcinoma, arterioportal shunt, and hemangioma in the cirrhotic liver. The differentiation of HCCs from these mimickers on preoperative imaging studies is of critical importance. Hence, we will review the typical and atypical imaging features of HCCs and the imaging features of its common mimickers. In addition, we will discuss how to solve these challenges in practice.

The effects of a transjugular intrahepatic portosystemic shunt on the diagnosis of hepatocellular cancer.

Background and aimsTransjugular intrahepatic portosystemic shunt (TIPS) may be placed to treat complications of portal hypertension by creating a conduit between the hepatic and portal vein. The diagnosis of hepatocellular carcinoma (HCC) is typically made by multiphasic imaging studies demonstrating arterial enhancement with washout on arterial, portal venous, and delayed phase imaging. The aim of our study was to determine how the presence of TIPS would affect the imaging diagnosis of HCC.MethodsThis was a single-center electronic database review of all patients who underwent multiphasic imaging with MRI or CT scan for HCC screening between January 2000 and July 2017 and who were subsequently diagnosed with HCC. Data collected included patient demographics, liver disease characteristics including CPT score, MELD-Na, AFP, type of imaging, tumor stage, and lab values at the time of HCC diagnosis. The diagnosis of HCC was made using LI-RADS criteria on contrast-enhanced CT or MR imaging and confirmed by chart abstraction as documented by the treating clinician. Demographic and imaging characteristics for HCC patients with and without TIPS were compared.ResultsA total of 279 patients met eligibility criteria for the study, 37 (13.2%) of whom had TIPS placed prior to diagnosis of HCC. There was no significant difference in demographics or liver disease characteristics between patients with and without TIPS. Compared to cirrhotic patients with no TIPS prior to HCC diagnosis, patients with TIPS had significantly more scans with a longer duration of surveillance until HCC diagnosis. However, LI-RADS criteria and stage of HCC at diagnosis were not significantly different between both groups. There were no differences in outcomes including liver transplant and survival.ConclusionThe presence of TIPS does not lead to a delayed diagnosis of HCC. It is associated, however, with greater duration of time from first scan to diagnosis of HCC.

Contrast-enhanced computed tomography may be helpful for characterizing and staging canine gastric tumors.

In humans, computed tomography (CT) is a widely performed technique for the diagnosis and staging of gastric tumors. The purpose of this retrospective case series study was to describe CT findings in a group of dogs with confirmed gastric tumors. For each included dog, the following CT parameters were recorded: gastric tumor location, tumor shape, gastric involvement pattern, tumor enhancement pattern in early and late phases, presence and location of lymphadenopathy, gastric tumor attenuation values, attenuation values of enlarged lymph nodes, maximum short-axis diameter (mm) of enlarged lymph node, maximum long-axis diameter (mm) of enlarged lymph node, and short-axis diameter to long-axis diameter ratio (short axis/long axis). A total of 16 dogs met inclusion criteria and had the following final diagnoses: five lymphoma, six adenocarcinoma, three inflammatory polyps, and two leiomyoma. In the early- and delayed-phase postcontrast images, the mean CT attenuation value for lymphoma was lower than that of other gastric tumors. Lymphadenopathy was widespread in lymphomas and regional in adenocarcinomas. Lymphadenopathy was not detected in leiomyomas. Lymph node measurements in lymphoma were larger than lymph node measurements in adenocarcinoma. Although there were overlapping findings for the different types of gastric tumors, contrast-enhanced CT provided helpful information for characterizing gastric tumors based on the following criteria: early and late enhancement patterns, the site of origin of the mass lesion, and extent of local invasion and distant metastases. Lymphoma should be considered for canine gastric tumors with low mean attenuation values during early- and delayed-phase postcontrast images, and widespread, bulky, and rounded lymphadenopathy.

Study on the Detection of CFRP Material with Subsurface Defects Using Barker-Coded Thermal Wave Imaging (BC-TWI) as a Nondestructive Inspection (NDI) Tool

In this paper, a Barker-coded thermal wave imaging approach is reported on the detection of carbon fiber reinforced polymer (CFRP) laminate with subsurface defects, using an integrated Barker code sequence and sinusoidal carrier-modulated laser as the excitation source. Artificial flat bottom holes as subsurface defects are prepared for the experimental investigation. Cross-correlation (CC) algorithm is applied for extracting characteristics of thermal wave signal and forming the corresponding peak delay time and phase images. The effects of Barker code sequence length and carrier-modulated frequency are investigated, which are both most important factors on the detectability of BC-TWI method. The results of the experiments show 5-bit Barker code and 0.1 Hz carrier frequency are the most suitable selection for enhancing inspection capability and obtaining the highest image SNR for a given CFRP laminate material. Furthermore, a comparative experiment is carried out between BC-TWI and lock-in thermography (LIT) method by taking the defect contrast and SNR into account. The results indicate that the BC-TWI CC phase image has higher contrast and SNR than the LIT phase image.

Fibrolamellar hepatocellular carcinoma: multiphasic CT features of the primary tumor on pre-therapy CT and pattern of distant metastases.

The aim of our study is to describe the multiphasic CT features of fibrolamellar hepatocellular carcinomas (FLHCCs) and pattern of distant metastases. 33 patients (mean age 28years: 17M/16F) with pathologically confirmed FLHCC and pre-treatment multiphasic CT were included in the study. Two abdominal radiologists evaluated the multiphasic CT imaging features of these 33 FLHCC patients in consensus. Solitary hepatic mass was seen in 67% (22/33). Mean tumor size was 11.3cm (range 4.6-22cm). Tumor was well-defined in 64% (21/33). In the pre-contrast CT, 91% (30/33) were hypoattenuating. Central stellate scar was present in 73% (24/33). In FLHCC having central stellate scar, calcification within the central scar was seen in 88% (21/24). In the hepatic arterial phase, 82% (27/33) were hyperattenuating relative to liver. In the portal venous phase, 36% (12/33) were hyperattenuating, 46% (15/33) were isoattenuating, and 18% (6/33) were hypoattenuating. In the delayed phase images, 24% (8/23) were hyperattenuating, 67% (22/33) were isoattenuating, and 9% (3/33) were hypoattenuating. Delayed enhancement of the central stellate scar was seen in 12% (4/33). Distant metastases were seen in 54% (18/33). The most common site of metastases was lungs and was seen in 89% (16/18) of the patients with metastatic disease. FLHCC typically manifests as a large, solitary mass demonstrating heterogeneous hypervascular enhancement in the arterial phase. Most tend to be isoattenuating in delayed phase. Central stellate scar with internal calcification is a useful imaging feature that can help in the diagnosis of FLHCC. Lungs are the most common site of distant metastases in FLHCC.

The capsule appearance of hepatocellular carcinoma in gadoxetic acid-enhanced MR imaging: Correlation with pathology and dynamic CT.

This study aimed to evaluate the capability of gadoxetic acid-enhanced MR (GAeMR) to detect presence of capsule appearance in hepatocellular carcinoma (HCC), and to correlate it with dynamic computed tomography (CT) and pathological features.Sixty-three patients (54: 9 = M: F, mean age 55.8) surgically confirmed HCCs with preoperative CT and GAeMR were included in this retrospective study. Two readers evaluated presence of capsule appearances on CT and GAeMR images in each phase including precontrast (Pre), portal phase (PP), delayed phase (DP), transitional phase (TP), and hepatobiliary phase (HBP). Histologic capsule was compared with CT and GAeMR. Diagnostic performance of CT and GAeMR of each phase for histologic capsule was evaluated and compared by receiver operating characteristic curve. Interobserver agreement was assessed with kappa statistics.Histologically the capsule was complete in 12.7% (8/63) and incomplete in 60.3% (38/63). Four cases (6.3%) were pseudocapsule. Interobserver agreement for capsule appearance on GAeMR was good in Pre (κ = 0.684), moderate in PP (κ = 0.434), poor in TP (κ = 0.187), fair in HBP (κ = 0.395), and moderate on CT in PP (κ = 0.476) and DP (κ = 0.485). Diagnostic performance and sensitivity for the histologic capsule in DP on CT was highest among PP on CT and other phases on GAeMR. DP on CT images showed a higher Az value than PP on CT images with statistical significance (P < .001). PP on MR images revealed higher Az value than PP on CT images.The capsule appearance was most frequently observed in the DP on CT with highest diagnostic performance, and so DP images should be obtained on CT study for liver mass categorization. GAeMR yielded comparable capsule appearance to CT with moderate interobserver agreement. Considering hypointense rim on the HBP as fibrous capsule on pathology should be refrained, and so further study is warranted to correlate HBP hypointense rim with pathologic findings.

The cardiovascular health score and the volume of carotid body in computed tomography angiography in patients with arterial hypertension

The cardiovascular health (CVH) score constitutes a reliable and measurable indicator of CVH proposed by the American Heart Association (AHA) calculated based on seven fundamental parameters, that is, smoking, body mass index, physical activity, healthy diet score, blood pressure, blood cholesterol, and fasting plasma glucose. The size and activity of carotid body (CB) play an important role in the pathogenesis of the cardiovascular system. The objective of this study was to define the relationship between the AHA CVH score and the volume of CB (VrCB+lCB) estimated based on computed tomography angiography (CTA) in patients with arterial hypertension. Studies were conducted on a group of 57 patients with arterial hypertension (age: 70.74 ± 8.21 years). The CVH score was calculated, and CTA of carotid arteries was carried out for all patients. The CB analysis was performed based on delayed phase imaging obtained from CTA of carotid arteries. Based on the CVH score value, CVH was determined as optimal (CVH score between 10 and 14 points), average (5 and 9 points), or inadequate (0 and 4 points). CVH score in the studied group of patients was 6.53 ± 1.81, whereas VrCB+lCB value was 38.58 ± 18.43 mm3. Patients with an inadequate CVH score (0–4 points) have statistically significantly higher VrCB+lCB, and they are fraught with VrCB+lCB ≥ median much more often than patients with an optimal CVH score (10–14 points). The receiver operating characteristic curve indicated a CVH score value of 6 as an optimal cutoff point to predict VrCB+lCB ≥ median. The CVH score ≤6 criterion indicates VrCB+lCB ≥ median with sensitivity of 58.6% and specificity of 71.4%. In the regression analysis, it was indicated that lower partial scores for physical activity, healthy diet score, and blood pressure in the AHA CVH evaluation constitute independent risk factors for higher VrCB+lCB. In the studied group of patients with arterial hypertension, an inversely proportional dependence between the CVH score and the size of CB is observed in CTA of carotid arteries.

MRI manifestations of hepatic perfusion disorders.

The present study aimed to analyze the magnetic resonance imaging (MRI) results from patients with hepatic perfusion disorders (HPD) and liver diseases, in order to assess the pathogenetic mechanisms. This was completed byanalyzing the causes of HPD in 35 patients to assess if they were associated with arterioportal shunt, and classify the patients according to results from the MRI scans. Of the 35 patients, 26 (74.3%) with HPD presented with hepatocellular carcinoma, a major cause of HPD. The HPD phenomenon in 35 patients was not identified as obvious abnormal lesions on T2WI and T1WI according to the isointensity on diffusion weighted images. Enhanced scanning showed hyperintense signals on the arterial phase images, isointense or hyperintense signals on portal phase and delayed phase images. According to their MRI findings, hepatic perfusion disorders may be divided into different types, as follows: Diffuse, lobe or segment type, wedge type and platy. The HPD phenomenon may herald an underlying abnormality of liver disease and MRI may accurately diagnose HPDs in liver diseases.

Best Protocol for Combined Contrast-Enhanced Thoracic and Abdominal CT for Lung Cancer: A Single-Institution Randomized Crossover Clinical Trial.

The purpose of this study was to evaluate the superiority of either of two protocols for combined contrast-enhanced thoracic and abdominal CT of patients with lung cancer by comparing contrast enhancement, contrast-related artifacts, image quality, and radiation dose. In this randomized controlled crossover clinical trial, 77 patients who underwent 203 CT examinations were enrolled. All patients underwent at least two examinations performed with both protocols. Protocol A consisted of two acquisitions: one 35-second delayed CT acquisition for the chest followed by a 70-second delayed abdominal acquisition. Protocol B was a single 60-second delayed acquisition covering the chest and the abdomen. Attenuation and noise of the aorta, pulmonary artery, and liver were measured. Contrast-related artifacts, mediastinal lymph node visualization, liver enhancement, and noise were visually scored. Dose-length product was recorded. Statistical analysis was performed by t and chi-square tests and kappa statistics. Contrast-related artifacts were more severe at all evaluated levels, and visualization of lymph node regions was statistically significantly worse with protocol A. There were no differences in enhancement or noise score of the liver. Tumor delineation and pleural findings were better evaluated with delayed phase images. Dose-length product was significantly higher with protocol A (645.0 vs 521.5 mGy · cm; p < 0.0001). A single 60-second delayed acquisition for thoracic and abdominal contrast-enhanced CT is associated with less contrast artifact and affords better visualization of lymph nodes at a lower radiation dose while acceptable vascular and hepatic contrast enhancement is maintained.

Prognostic significance of retention index of bone marrow on dual-phase 18F-fluorodeoxyglucose positron emission tomography/computed tomography in patients with diffuse large B-cell lymphoma.

The purpose of this study was to determine the prognostic significance of F-18 fluorodeoxyglucose (FDG) uptake on a dual-phase positron emission tomography/computed tomography (PET/CT), focusing on the increment in maximal standardized uptake value (SUVinc) of tumor and bone marrow (BM) between initial and delayed phase images and retention index (RI) of tumor and BM, in patients with diffuse large B-cell lymphoma (DLBCL).From September 2009 to January 2013, 70 patients (37 males and 33 females, aged 60.6 ± 17.5 years) with DLBCL who had undergone dual-phase FDG PET/CT scans for pretreatment staging were enrolled. The patients subsequently received combination chemotherapy with rituximab. The dual-phase SUV, including SUVinc of tumor (SUVinc-t), RI of tumor (RI-t), SUVinc of BM, and RI of BM were measured. The clinical observation period was from September 2009 to December 2014. Both univariate and multivariate analyses were then used to assess the prognostic significance of SUVinc, RI, international prognostic index (IPI), gender, age, clinical stage, and laboratory tests.The median follow-up time was 35.5 months. The 3-year overall survival (OS) for patients with low/high SUVinc-t (cut-off 2.0) and for patients with low/high RI-t (cut-off 20) were 87.5%/ 62.1% (P = .08) and 83.3%/ 62.7% (P = .14), respectively. The 3-year OS for patients with SUVinc-i < 0.35 and for those with SUVinc-i ≥ 0.35 were 73.2% and 53.3%, respectively (P = .10). The 3-year OS for patients with RI-i < 45 and for those with RI-i ≥ 45 were 72.7% and 37.5%, respectively (P = .02). Subsequently, the Cox multivariate forward proportional hazards model revealed that a higher RI-i (hazard ratio: 4.49; 95% confidence interval: 1.64-12.32; P = .0035) and IPI were independent prognostic factors affecting OS.For patients with DLBCL, an elevated RI-i (≥45) was a predictor for shorter OS, independent of IPI score. It added to the value of pretreatment dual-phase FDG PET/CT scans.