Acta Radiologica

Intravoxel incoherent motion (IVIM) tissue parameters depend on the threshold b-value.

To explore how threshold b-value impacts PF (f), D_slow (D), and D_fast (D*) values and their performance for liver fibrosis detection.

Fifteen healthy volunteers and 33 hepatitis B patients were included. With a 1.5-T magnetic resonance (MR) scanner and respiration gating, IVIM data were acquired with ten b-values of 10, 20, 40, 60, 80, 100, 150, 200, 400, and 800 s/mm². Signal measurement was performed on the right liver. Segmented-unconstrained analysis was used to compute IVIM parameters and six threshold b-values in the range of 40–200 s/mm² were compared. PF, D_slow, and D_fast values were placed along the x-axis, y-axis, and z-axis, and a plane was defined to separate volunteers from patients.

Higher threshold b-values were associated with higher PF measurement; while lower threshold b-values led to higher D_slow and D_fast measurements. The dependence of PF, D_slow, and D_fast on threshold b-value differed between healthy livers and fibrotic livers; with the healthy livers showing a higher dependence. Threshold b-value = 60 s/mm² showed the largest mean distance between healthy liver datapoints vs. fibrotic liver datapoints, and a classification and regression tree showed that a combination of PF (PF < 9.5%), D_slow (D_slow < 1.239 × 10^–3 mm²/s), and D_fast (D_fast < 20.85 × 10^–3 mm²/s) differentiated healthy individuals and all individual fibrotic livers with an area under the curve of logistic regression (AUC) of 1.

For segmented-unconstrained analysis, the selection of threshold b-value = 60 s/mm² improves IVIM differentiation between healthy livers and fibrotic livers.

Early detection of breast cancer (BC) is crucial in lowering the mortality.

To present an overview of studies concerning computer-aided detection (CAD) in screening mammography for early detection of BC and compare diagnostic accuracy and recall rates (RR) of single reading (SR) with SR + CAD and double reading (DR) with SR + CAD.

PRISMA guidelines were used as a review protocol. Articles on clinical trials concerning CAD for detection of BC in a screening population were included. The literature search resulted in 1522 records. A total of 1491 records were excluded by abstract and 18 were excluded by full text reading. A total of 13 articles were included.

All but two studies from the SR vs. SR + CAD group showed an increased sensitivity and/or cancer detection rate (CDR) when adding CAD. The DR vs. SR + CAD group showed no significant differences in sensitivity and CDR. Adding CAD to SR increased the RR and decreased the specificity in all but one study. For the DR vs. SR + CAD group only one study reported a significant difference in RR.

All but two studies showed an increase in RR, sensitivity and CDR when adding CAD to SR. Compared to DR no statistically significant differences in sensitivity or CDR were reported. Additional studies based on organized population-based screening programs, with longer follow-up time, high-volume readers, and digital mammography are needed to evaluate the efficacy of CAD.

Motion artifacts can reduce image quality of breast magnetic resonance imaging (MRI). There is a lack of data regarding their effect on diagnostic estimates.

To evaluate factors that potentially influence readers’ diagnostic estimates in breast MRI: motion artifacts; amount of fibroglandular tissue; background parenchymal enhancement; lesion size; and lesion type.

This Institutional Review Board-approved, retrospective, cross-sectional, single-center study included 320 patients (mean age = 55.1 years) with 334 histologically verified breast lesions (139 benign, 195 malignant) who underwent breast MRI. Two expert breast radiologists evaluated the images considering: motion artifacts (1 = minimal to 4 = marked); fibroglandular tissue (BI-RADS FGT); background parenchymal enhancement (BI-RADS BPE); lesion size; lesion type; and BI-RADS score. Univariate (Chi-square) and multivariate (Generalized Estimation Equations [GEE]) statistics were used to identify factors influencing sensitivity, specificity, and accuracy.

Lesions were: 230 mass (68.9%) and 59 non-mass (17.7%), no foci. Forty-five lesions (13.5%) did not enhance in MRI but were suspicious or unclear in conventional imaging. Sensitivity, specificity, and accuracy were 93.8%, 83.4%, and 89.8% for Reader 1 and 95.4%, 87.8%, and 91.9% for Reader 2. Lower sensitivity was observed in case of increased motion artifacts (P = 0.007), non-mass lesions (P < 0.001), and small lesions ≤ 10 mm (P < 0.021). No further factors (e.g. BPE, FGT) significantly influenced diagnostic estimates. At multivariate analysis, lesion type and size were retained as independent factors influencing the diagnostic performance (P < 0.033).

Motion artifacts can impair lesion characterization with breast MRI, but lesion type and small size have the strongest influence on diagnostic estimates.

The maximum value of the strain ratio (SR) is a newly developed measure in strain-elastography.

To prospectively compare the diagnostic performance of three different measures of strain-elastography, the maximum value of the SR (SR_max), the average value of the SR (SR_ave), and the color map, for differentiating benign and malignant breast lesions.

We obtained the SR_max and SR_ave of 314 lesions from 290 patients with the tissue to nodule SR and color map using a five-degree scoring system. The diagnostic performances of the SR_max, SR_ave, and color map were compared after obtaining the area under the receiver operating characteristic (ROC) curves (AUCs) of each parameter.

The AUC of the SR_max (0.7674) was larger than the AUCs of the SR_ave (0.7138) and color map (0.6324), with statistical significance (P = 0.0383 for SR_max vs. SR_ave, P = 0.0000 for SR_max vs. color map). The AUC of the SR_ave was larger than that of the color map; however, there was no significant difference. The optimal cut-off point of the SR_max that balanced the sensitivity (91.12%) and specificity (50.81%) was 5.16.

The SR_max is a more reliable diagnostic tool than the SR_ave and color map for differentiating benign and malignant breast lesions.

The goals of neoadjuvant chemotherapy (NAC) are to reduce tumor volume and to offer a prognostic indicator in assessing treatment response. Contrast-enhanced magnetic resonance imaging (CE-MRI) is an established method for evaluating response to NAC in patients with breast cancer.

To validate the role of unenhanced MRI (ue-MRI) compared to CE-MRI for assessing response to NAC in women with breast cancer.

Seventy-one patients with ongoing NAC for breast cancer underwent MRI before, during, and at the end of NAC. Ue-MRI was performed with T2-weighted sequences with iterative decomposition of water and fat and diffusion-weighted sequences. CE-MRI was performed using three-dimensional T1-weighted sequences before and after administration of gadobenate dimeglumine. Two blinded observers rated ue-MRI and CE-MRI for the evaluation of tumor response. Statistical analysis was performed to compare lesion size and ADC values changes during therapy, as well as inter-observer agreement.

There were no statistically significant differences between ue-MRI and CE-MRI sequences for evaluation of lesion size at baseline and after every cycle of treatment (P > 0.05). The mean tumor ADC values at baseline and across the cycles of NAC were significantly different for the responder group.

Ue-MRI can achieve similar results to CE-MRI for the assessment of tumor response to NAC. ADC values can differentiate responders from non-responders.

Coronary computed tomography angiography (CCTA) is increasingly used to detect coronary artery disease (CAD), but long-term follow-up studies are still scarce.

To evaluate the prognostic value of CCTA in patients with suspected CAD.

A total of 1205 consecutive CCTA patients with chest pain were classified as normal coronary arteries, non-obstructive CAD, or obstructive CAD. The primary outcome was major adverse cardiac event (MACE), defined as a composite outcome including cardiac death, myocardial infarction, unstable angina pectoris, or late revascularization (after >90 days).

Over 7.5 years follow-up (median = 3.1 years), Kaplan–Meier estimates demonstrated a MACE in 1.0%, 4.6%, and 20.7% in normal coronary arteries, non-obstructive CAD, and obstructive CAD, respectively. Log rank test for pairwise comparisons showed significant differences between non-obstructive CAD and normal coronary arteries (P = 0.023) and between obstructive CAD and normal coronary arteries (P < 0.001). In a multivariable analysis, adjusting for classical risk factors, non-obstructive CAD and obstructive CAD were independent predictors of MACE, with hazard ratios (HR) of 3.22 (P = 0.041) and 25.18 (P < 0.001), respectively.

Patients with normal coronary arteries have excellent long-term prognosis, but the risk for MACE increases with non-obstructive and obstructive CAD. Both non-obstructive and obstructive CAD are independently associated with future ischemic events.

Sigmoid sinus wall reconstruction (SSWR) is a proven effective treatment for pulsatile tinnitus (PT) caused by sigmoid sinus wall dehiscence (SSWD) with or without sigmoid sinus diverticulum (SSD); however, comprehensive analysis of the postoperative imaging manifestations has not yet been reported.

To analyze temporal bone computed tomography (CT) imaging features following SSWR in patients with PT.

Following SSWR, temporal bone contrast-enhanced high-resolution CT (HRCT) images from 33 PT cases were retrospectively analyzed. Patients were divided into two groups based on follow-up interval: a short-interval group (≤18 months, 12 cases) and a long-interval group (>18 months, 21 cases). The mending material density and morphology was analyzed. Postoperative changes of the venous sinus were evaluated. Imaging manifestations of the normal temporal bone and mastoid air cells adjacent to the operative field were observed.

The order of CT values of mending materials was significantly lower in the short-interval group than in the long-interval group (Z = −4.716, P < 0.001); the incidence of complete newly remodeled cortical bone on the rim of the mending materials was significantly higher in the long-interval group than in the short-interval group (P < 0.001). Eleven patients (33.3%) showed varying degrees of remnant SSWD. The mending materials and normal mastoid bone structure showed complete fusion (n = 12, 36.4%), partial fusion (n = 16, 48.5%), or complete separation (n = 5, 15.2%).

Temporal bone contrast-enhanced HRCT can be used to observe imaging features of the mending materials, venous sinus, adjacent normal temporal bone and mastoid air cells following SSWR.

Multiple rounds of head computed tomography (CT) scans increase the risk of radiation-induced lens opacification.

To investigate the effects of CT eye shielding and topogram-based tube current modulation (TCM) on the radiation dose received by the lens and the image quality of nasal and periorbital imaging.

An anthropomorphic phantom was CT-scanned using either automatic tube current modulation or a fixed tube current. The lens radiation dose was estimated using cropped Gafchromic films irradiated with or without a shield over the orbit. Image quality, assessed using regions of interest drawn on the bilateral extraorbital areas and the nasal bone with a water-based marker, was evaluated using both a signal-to-noise ratio (SNR) and contrast-noise ratio (CNR). Two CT specialists independently assessed image artifacts using a three-point Likert scale.

The estimated radiation dose received by the lens was significantly lower when barium sulfate or bismuth-antimony shields were used in conjunction with a fixed tube current (22.0% and 35.6% reduction, respectively). Topogram-based TCM mitigated the beam hardening-associated artifacts of bismuth-antimony and barium sulfate shields. This increased the SNR by 21.6% in the extraorbital region and the CNR by 7.2% between the nasal bones and extraorbital regions. The combination of topogram-based TCM and barium sulfate or bismuth-antimony shields reduced lens doses by 12.2% and 27.2%, respectively.

Image artifacts induced by the bismuth-antimony shield at a fixed tube current for lenticular radioprotection were significantly reduced by topogram-based TCM, which increased the SNR of the anthropomorphic nasal bones and periorbital tissues.

Radiation worker categorization and exposure monitoring practices must be proportional to the current working environment.

To analyze exposure data of Finnish radiological workers and to estimate the magnitude and frequency of their potential occupational radiation exposure, and to propose appropriate radiation worker categorization.

Estimates of the probabilities of annual effective doses exceeding certain levels were obtained by calculating the survival function of a lognormal probability density function (PDF) fitted in the measured occupational exposure data.

The estimated probabilities of exceeding annual effective dose limits of 1 mSv, 6 mSv, and 20 mSv were in the order of 1:200, 1:10,000, and 1:500,000 per person, respectively.

It is very unlikely that the Category B annual effective dose limit of 6 mSv could even potentially be exceeded using modern equipment and appropriate working methods. Therefore, in terms of estimated effective dose, workers in diagnostic and interventional radiology could be placed into Category B in Finland. Current national personal monitoring practice could be replaced or supplemented using active personal dosimeters, which offer more effective means for optimizing working methods.

Positron emission tomography/computed tomography (PET/CT) is a useful imaging adjunct in patients with sarcoma. Intra-articular and peri-articular 18F-fluoro-2-deoxy-D-glucose (FDG) avid lesions are often discovered incidentally.

To describe the etiology, appearance, and standardized uptake values (SUV) of incidentally detected FDG avid intra-articular and peri-articular foci in patients with sarcoma.

The institutional sarcoma database between November 2011 and November 2016 was retrospectively reviewed. Patients were included if a PET/CT scan was performed and an FDG avid intra-articular or peri-articular focus was found that was distinct from the primary sarcoma.

The majority of FDG avid foci represented benign, non-physiologic conditions such as osteoarthritis, enthesopathy, bursitis, and post-surgical changes. Six patients each had radiographic features consistent with tenosynovial giant cell tumor (TSGCT) and metastatic disease, respectively. Lower SUV, bilateral findings, and the absence of metastatic disease elsewhere were associated with benign etiologies. There was a statistically significant difference between the mean SUV measured in patients with TSGCT and those with benign, non-physiologic conditions (P < 0.001). The difference between the benign, non-physiologic cohort and the cohort with widespread metastatic disease did not reach statistical significance (P = 0.07).

In patients with soft-tissue or osseous sarcomas, isolated FDG avid intra-articular or peri-articular foci without additional metastatic lesions likely represent benign processes. Isolated intra-articular or peri-articular foci with significantly elevated SUV measurements were favored to represent TSGCT in this series.

Computed tomography (CT) is superior to conventional radiography (CR) for assessing internal fixation of pelvic fractures, but with a higher radiation exposure. Low-dose CT (LDCT) could possibly have a sufficient diagnostic accuracy but with a lower radiation dose.

To compare postoperative diagnostic accuracy of LDCT and CR after open reduction and internal fixation of pelvic fracture.

Twenty-one patients were examined with LDCT and CR 0–9 days after surgery. The examinations were reviewed by two musculoskeletal radiologists. Hardware, degree of fracture reduction, image quality, and reviewing time were assessed, and effective radiation dose was calculated. Inter-reader agreement was calculated.

LDCT was significantly better than CR in determining whether hardware positioning was assessable (P < 0.001). Acetabular congruence was assessable in all fractured patients with LDCT. In 12 of the 32 assessments with CR of patients with an acetabular fracture, joint congruence was not assessable due to overlapping hardware (P = 0.001). Image quality was significantly higher for LDCT. Median time to review was 240 s for LDCT compared to 180 s for CR. Effective dose was 0.79 mSv for LDCT compared to 0.32 mSv for CR (P < 0.001).

LDCT is more reliable than CR in assessing hardware position and fracture reduction. Joint congruency is sometimes not possible to assess with CR, due to overlapping hardware. The image quality is higher, but also the effective dose, with LDCT than with CR.

There is no consensus regarding the minimum number of joints that should be included in an ultrasound (US) scoring system to reliably assess for disease activity in rheumatoid arthritis (RA).

To assess whether simplified US protocols for hand examination are as informative as the examination of 22 joints in patients with RA, and to correlate the US parameters with disease activity (DAS-28).

This is a cross-sectional study of 224 RA patients stratified based on their DAS-28 scores and assessed using eight preselected US examination protocols, including 22, 18, 16, 14, ten, eight, and two different combinations of four joints, respectively.

We found a significant difference between US hand scores regarding their ability to detect active inflammation and erosions. DAS-28 scores correlated very well with the power Doppler (PD) scores generated by all eight US examination protocols (r = 0.89–1, P < 0.05), irrespective of patients' disease activity. Simplified US scores missed information on presence of PD in 20.6–40.2% patients (P < 0.05) and misdiagnosed non-erosive hand RA in 12–38.4% patients (P < 0.05), depending on the number of joints excluded from US hand examination.

Preselected simplified US scores are less reliable in appreciating the disease burden when compared with an extended protocol for 22 joint US examination, raising clinicians' awareness regarding the need to comprehensively assess multiple hand joints to reliably rule out subclinical inflammation.

Although several studies were conducted to put forth the biomechanical function of anterior intermeniscal ligament (AIML) on the stability of meniscal structures, there are few data on the etiology of the early degeneration of discoid type compared to the normal shaped ones.

To determine the AIML subtypes and accompanying meniscal pathologies in discoid lateral menisci (DLM) on knee MRI exams.

Knee MRI exams of 171 individuals with DLM were reviewed. DLMs and AIMLs were typed according to Watanabe’s classification and Nelson-Laprade classification, respectively. Medial and lateral menisci were evaluated for tear and menisco-capsular pathology. Pearson’s correlation test was used for statistical analysis.

DLM was type I in 83 (48.5%) individuals and type II in 88 (51.5%) individuals. AIML was absent in 90 (52.6%) participants; type I AIML was seen in 38 out 81 (22.2%), type II in 31 out of 81(18.1%), and type III in 12 out of 81 (7%). Meniscal pathology was observed in 56 (32.7%) individuals as follows: menisco-capsular strain/separation in 25 (14.6%); medial meniscal tear in 22 (12.8%); and lateral meniscal tear in nine (5.2%); Of these 56 cases, 26 (46%) had no AIML, 15 cases (27%) had type I, nine cases (16%) had type II, and six cases (11%) had type III AIML.

No statistically significant correlation was found between the type of DLM and type of AIML (P = 0.855), between the type of DLM and meniscal pathology (P = 0.791), or between the type of AIML and meniscal pathology (P = 0.282).

Magnetic resonance (MR) spectroscopy (¹H-MRS) has been demonstrated to be useful in grading glioma, but the utility in assessing cellular proliferation activity and prognosis correlated with the expression of minichromosome maintenance protein 2 (MCM2) has not been reported.

To explore the correlation between proton MR spectroscopy parameters (including choline [Cho]/creatine [Cr], N-acetyl aspartate [NAA]/Cr, and Cho/NAA ratios) and the expression of MCM2 and to further evaluate whether ¹H-MRS can predict cell proliferative activity and provide prognostic information in high-grade gliomas (HGGs).

Forty-three patients with histopathologically confirmed gliomas were involved in this study. All patients underwent ¹H-MRS examination before surgery. Proliferative activity of gliomas was evaluated by MCM2 labeling index (LI). Pearson correlation analysis and empiric receiver operating characteristic (ROC) curves were performed. The Kaplan–Meier method and Cox regression were used for survival analysis.

Significant correlation was observed between the Cho/Cr ratio and MCM2 LI (r = 0.522, P < 0.01); however, there was no correlation between MCM2 LI and the Cho/NAA or NAA/Cr ratios (r = 0.295, P = 0.55 and r = −0.042, P = 0.788, respectively). According to ROC analysis, MCM2 LI of 50% and Cho/Cr ratio of 2.68 represented the optimized cut-off values, respectively, to distinguish longer or shorter survival than 15 months in HGGs patients. Multivariate analysis revealed that both the Cho/Cr ratio and MCM2 expression were independent prognostic markers.

Cho/Cr ratio has a potential in predicting the expression of MCM2 and can evaluate cell proliferative activity noninvasively. Both the Cho/Cr ratio and MCM2 expression are independent prognostic markers in patients with HGGs.

Adhesio interthalamica (AI) is a small structure connecting bilateral thalami.

To evaluate the effects of patient age, sex, and lateral diameter of the third ventricle on the long diameter of the AI using multivariate analyses based on magnetic resonance (MR) images obtained with 3.0-T scanners.

This clinical retrospective study included images of 153 patients who underwent MR examination using 3.0-T scanners. The long diameter of the AI and lateral diameter of the third ventricle were measured on images in the mid-sagittal plane and axial plane at the anterior commissure, respectively. Univariate and multivariate analyses were performed.

AI was observed in 138 patients (70 men, 68 women; mean age = 63.7 ± 13.7 years; mean AI size =5.34 ± 1.63 mm). By univariate analyses, patient age (r = −0.262, P = 0.002), sex (P = 0.010), and lateral diameter of the third ventricle (r = −0.642, P < 0.001) were significantly associated with the long diameter of the AI. With multiple linear regression analyses with a stepwise selection of parameters, only the lateral diameter of the third ventricle (estimate = −0.432, P < 0.001) was significantly associated with the long diameter of the AI. The lateral diameter of the third ventricle was longer in patients without AI (15 patients) than in those with AI (P = 0.006).

The lateral diameter of the third ventricle was a major factor negatively associated with the long diameter of the AI.

Better selection of patients with intermediate and high-risk stage I endometrial carcinoma (EC) for lymphadenectomy has an important effect on the prognosis.

To investigate the role of apparent diffusion coefficient (ADC) measurements in the assessment of stage I EC patients based on three risk categories.

We retrospectively studied 80 patients with EC and 28 cervical cancer patients with normal endometrium. 1.5-T conventional magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) (b = 0, 1000 s/mm²) were performed, and ADC values were calculated. Sixty-eight stage I EC patients were divided into three groups: low-risk EC (group 1); intermediate-risk EC (group 2); and high-risk EC (group 3). The remaining 12 EC patients were in stages II and III. Intraclass coefficient, Mann–Whitney U test, Kruskal–Wallis test, and receiver operating characteristics were used for statistical analysis.

The mean ADC values ( × 10^–3 mm² /s) were 0.851 ± 0.131, 0.734 ± 0.108, and 0.710 ± 0.108 for groups 1, 2 and 3, respectively. Significant statistical differences were achieved for the three groups (P = 0.0005). The mean ADC values of group 1 were significantly lower than those in group 2 + 3 (0.725 ± 0.106; P = 0.0001). For the prediction of groups 2 + 3, the area under the curve of 0.786 and the cut-off value of ≤ 0.742 were identified, with a sensitivity, specificity, and accuracy of 66.67%, 84.09%, and 73.53%, respectively.

ADC measurements may have the potential to select intermediate-risk and high-risk stage I EC patients for lymphadenectomy.