Acta Radiologica

Combinations

*Equal contributors.

The aim of this study was to test the feasibility of using an automated standard three-dimensional (3D) ultrasound (US) device fused with standard mammography for the first time in breast cancer patients.

Digital mammograms and 3D automated US images were obtained in 23 patients with highly suspicious breast lesions. A recently developed fusion machine consisting of an ABVS 3D US transducer from an Acuson S2000 machine and a conventional Mammomat Inspiration device (both Siemens Healthcare GmbH, Erlangen, Germany) were used for the purpose. The feasibility of the examinations, imaging coverage, and patients' experience of the procedure were examined.

In 15 out of 19 patients, the region of interest (ROI) with the tumor marked in the mammogram was visible on US. The examination was experienced positively by the patients, with no unexpected pain or injury. The examination was time-saving and well tolerated.

In conclusion, we have shown initial clinical feasibility of an US/radiography fusion prototype with good localization and evaluation of the ROIs. The combined examination was well tolerated. The simultaneous evaluation with mammography and US imaging may be able to improve detection and reduce examiner-related variability.

Microvessel density (MVD) is associated with grade and prognosis in breast tumors. However, conventional color Doppler flow (CDF) imaging has been limited to represent MVD of breast tumors.

To evaluate whether a new Doppler imaging technique (AngioPLUS) can represent MVD of breast tumors.

The institutional review board approved this retrospective study, and patients’ informed consent was waived. CDF and AngioPLUS were available in pathologically confirmed 55 breast tumors of 53 women. For each lesion, vascular flow patterns (distribution and amount) of both Doppler images were retrospectively reviewed, and MVD was measured using immunohistochemical analysis of the biopsied tissue sections. MVD was subcategorized as low or high group with reference to the median. The associations between the Doppler features and MVD were evaluated using Fisher’s exact test and Student’s t test.

Of the 55 masses, 28 (50.9%) were benign and 27 (49.1%) were malignant. Vascular flow distribution and amount of both Doppler imaging were different between the benign and malignant lesions (CDF, P = 0.020 and P = 0.010; AngioPLUS, P = 0.002 and P = 0.005). MVD had no significant relationships with CDF features, but vascular flow distribution on AngioPLUS showed significant differences between the lesions with low and high MVD (P = 0.020); Combined distribution was more frequent in the high MVD lesions than in the low MVD lesions (17/28, 60.7% vs. 6/27, 22.2%).

Our data confirmed the correlation between a new Doppler imaging technique, AngioPLUS, and MVD. We suggest that AngioPLUS can be used for assessing MVD in breast tumors.

Long-term intensive training induces physiological, morphological, and functional adaption of the athlete’s heart.

To evaluate the development of athlete’s heart during a mid-term follow-up of competitive athletes using cardiac magnetic resonance (CMR).

Eighteen competitive long-distance runners and triathletes (age 43 ± 13 years, 3 women) were prospectively examined in a longitudinal follow-up study 5.05 ± 0.6 years after baseline. CMR at 1.5-T was performed for functional and late gadolinium enhancement (LGE) imaging. Left ventricular (LV) and right ventricular (RV) end-diastolic volume (LVEDV, RVEDV) as well as ejection fraction (LVEF, RVEF), LV myocardial mass (LVMM), and atrial sizes were determined and compared to baseline in matched pairs statistics for paired difference.

LVEDV (197 ± 38 mL vs. 196 ± 38 mL, paired difference −0.9 mL, P = 0.7) and LVEF (62 ± 7% vs. 62 ± 5%, paired difference 0.1%, P = 0.9) did not change during the follow-up period, whereas LVMM increased significantly (149 ± 31 g vs.164 ± 32 g, paired difference 14 g, P < 0.0001). RVEDV significantly increased from 221 ± 47 mL at baseline to 230 ± 52 mL (paired difference 10 mL, P = 0.0033). RVEF decreased from baseline 57 ± 8% to 53 ± 7% (paired difference −3%, P = 0.0234). Left atrial size showed no significant changes (24 ± 5 cm² vs. 25 ± 6 cm², paired difference 0.5 cm², P = 0.17) and right atrial size increased significantly (30 ± 5 cm² vs. 32 ± 4 cm², paired difference 2 cm², P = 0.0054).

This study supports the theory of ongoing remodeling in an athlete’s heart. Predominantly the right heart can further enlarge in a mid-term period. This response seems not linearly dependent on a steady, decreased, or increased training volume.

Atherosclerosis is the main cause of cardiovascular and cerebrovascular diseases. Non-invasive molecular imaging to detect and characterize the plaques is essential for reducing life-threatening cardiovascular events.

To investigate the possibility of the anti-tenascin-C-USPIO specific probe as a molecular marker of atherosclerotic plaques detected by 7.0-T magnetic resonance imaging (MRI).

Twenty ApoE^-/- mice fed with a high fat diet were used for detecting the aorta arch atherosclerotic plaques by 7.0-T MRI at 16 and 24 weeks. Ten mice in the targeted group were injected with anti-tenascin-C-USPIO and another ten in the control group were injected with pure USPIO (n = 5 each time point in each group). Histopathologic examination was used to evaluate the plaques and immunohistochemistry analysis was used to compare tenascin-C expression.

The relative signal intensity (rSI) changes of the targeted group decreased more than those of the control group (16 weeks: −15.65 ± 0.78% vs. −3.43 ± 2.57%; 24 weeks: −26.38 ± 1.54% vs. −11.12 ± 1.60%, respectively; P < 0.05). Histopathological analyses demonstrated visible atherosclerotic plaques formation and development over time from 16 weeks to 24 weeks. Tenascin-C expression of the plaques at 24 weeks was higher than that at 16 weeks (0.22 ± 0.04 vs. 0.13 ± 0.02, P < 0.05). The MR images correlated well with the progression of atherosclerotic plaques.

Tenascin-C expression increased with the progression of atherosclerosis. Anti-tenascin-C-USPIO could provide a useful molecular imaging tool for detecting and monitoring atherosclerotic plaques by MRI.

Symptomatic renal artery stenosis (RAS) is mainly treated with pharmacological blood pressure control, sometimes with percutaneous transluminal renal angioplasty (PTRA). It is unclear if PTRA benefits these patients over time.

To determine long-term renal function, morbidity, and mortality in patients with symptomatic RAS treated with PTRA, and whether long-term outcomes are associated with angiographic restenosis.

Retrospective single-center, long-term follow-up of 57 patients with atherosclerotic RAS treated with PTRA with stent during 1995–2004 and investigated for restenosis with angiography after one year. Outcomes were retrieved from medical records and from mandatory healthcare registries. Mortality rates were related to expected survival in an age- and gender-matched population, using a life-table database. Surviving patients were assessed with blood pressures, laboratory tests, duplex ultrasonography, and radioisotope renography.

Median follow-up was 11 years 7 months. Major indications for PTRA were therapy-resistant hypertension and declining renal function. Angiographic restenosis at one year was found in 21 of 57 patients (37%). Thirty-six patients (60%) died during follow-up. Main cause of death was cardiovascular events (54%). Mortality was significantly increased, and morbidity and healthcare utilization were high. Hypertension control during follow-up was stable with persistent need for anti-hypertensive medication, and renal function remained moderately reduced with no long-term difference between patients with vs. without restenosis.

Long-term prognosis after PTRA for atherosclerotic RAS is dismal, with high mortality and morbidity and reduced renal function, despite maintained hypertension control. Restenosis does not appear to affect late outcome.

Uterine fibroid embolization (UFE) is a minimally invasive imaging-guided treatment using radiation exposure.

To compare the patients’ radiation exposure during UFE before and after introduction of a new X-ray imaging platform.

Forty-one patients were enrolled in a prospective, comparative two-arm project before and after introduction of a new X-ray imaging platform with reduced dose settings, i.e. novel real-time image processing techniques (AlluraClarity). Demographic, pre-interventional imaging, and procedural data, including dose area product (DAP) and estimated organ dose on the ovaries and uterus, were recorded and angiographic quality of overall procedure was assessed.

There were no significant differences in demographic characteristics and preoperative fibroid and uterine volumes in the two groups. The new imaging platform led to a significant reduction in mean total DAP (102 vs. 438 Gy.cm²; P < 0.001), mean fluoroscopy DAP (32 vs. 138 Gy.cm²; P < 0.001), mean acquisition DAP (70 vs. 300 Gy.cm²; P < 0.001), and acquisition DAP estimated organ dose in ovaries (42 vs. 118 mGy; P < 0.001) and uterus (40 vs. 118 mGy, P < 0.001), without impairment of the procedure and angiographic image quality.

A substantial 77% reduction of DAP values and 64% and 66% reduction in organ dose on ovaries and uterus, respectively, was demonstrated with the new imaging platform, while maintaining optimal imaging quality and efficacy.

Although transarterial embolization (TAE) can powerfully control postpartum hemorrhage (PPH), clinical failure of TAE is not uncommon.

To discover whether any parameters could predict timely clinical failure of TAE, then whether a supplementary intervention could be promptly initiated.

We retrospectively analyzed 118 TAE procedures in 113 patients with PPH performed at our institution between January 2012 and May 2015. The patients were divided into the following groups: clinically successful TAE and failed TAE. Successful TAE was defined as obviation of supplementary embolization or surgical intervention for hemostasis. Gestational conditions, angiographic factors, maternal vital signs, and laboratory data were compared between the two groups.

In total, 100 (84.8%) TAEs were clinically successful. Multivariate logistic regression analyses revealed independent risk factors of TAE clinical failure, including the requirement for augmented embolic agents, placental retention, and international normalized ratio > 1.3 (P = 0.009, 0.001, and 0.005, respectively). The post-TAE shock index was significantly associated with TAE failure, using a cut-off value of 0.8.

The discovered independent risk factors of TAE clinical failure existed before or during the TAE procedure and could not reflect the post-TAE conditions. Although the post-TAE shock index was not an independent factor, it reflected the conditions after TAE and could indicate TAE clinical failure timely.

A novel, multi-energy, dual-layer spectral detector computed tomography (SDCT) is commercially available now with the vendor’s claim that it yields the same or better quality of polychromatic, conventional CT images like modern single-energy CT scanners without any radiation dose penalty.

To intra-individually compare the quality of conventional polychromatic CT images acquired with a dual-layer spectral detector (SDCT) and the latest generation 128-row single-energy-detector (CT128) from the same manufacturer.

Fifty patients underwent portal-venous phase, thoracic-abdominal CT scans with the SDCT and prior CT128 imaging. The SDCT scanning protocol was adapted to yield a similar estimated dose length product (DLP) as the CT128. Patient dose optimization by automatic tube current modulation and CT image reconstruction with a state-of-the-art iterative algorithm were identical on both scanners. CT image contrast-to-noise ratio (CNR) was compared between the SDCT and CT128 in different anatomic structures. Image quality and noise were assessed independently by two readers with 5-point-Likert-scales. Volume CT dose index (CTDI_vol), and DLP were recorded and normalized to 68 cm acquisition length (DLP₆₈).

The SDCT yielded higher mean CNR values of 30.0% ± 2.0% (26.4–32.5%) in all anatomic structures (P < 0.001) and excellent scores for qualitative parameters surpassing the CT128 (all P < 0.0001) with substantial inter-rater agreement (κ ≥ 0.801). Despite adapted scan protocols the SDCT yielded lower values for CTDI_vol (–10.1 ± 12.8%), DLP (−13.1 ± 13.9%), and DLP₆₈ (–15.3 ± 16.9%) than the CT128 (all P < 0.0001).

The SDCT scanner yielded better CT image quality compared to the CT128 and lower radiation dose parameters.

Metastatic pheochromocytoma and paraganglioma (PCs/PGLs) show high germline mutation, and ¹⁸F-FDG and ⁶⁸Ga-DOTA peptide positron emission tomography/computed tomography (PET/CT) imaging are recommended for the diagnosis of metastatic of PCs. However, there has been lack of direct comparison of the two modalities in the diagnosis of metastatic of PCs up to now.

To evaluate and compare the value of localization of ⁶⁸Ga-somatostatin receptor analogs and ¹⁸F-FDG in the diagnosis of metastatic PCs/PGLs.

A comprehensive literature search of PubMed/MEDLINE, ScienceDirect, and Web of Science was performed in accordance with the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines published in August 2016. We critically reviewed all studies based on the PICOS criteria. QUADAS-2 was used to evaluate the quality of the methodology of the included studies.

This meta-analysis included 17 studies (629 patients, average age [mean ± SD] = 42.7 ± 6.3 years). The pooled sensitivity and specificity of ¹⁸F-FDG and ⁶⁸Ga peptides were 0.85 (95% confidence interval [CI] = 0.78–0.91) and 0.55 (95% CI = 0.37–0.73), and 0.95 (95% CI = 0.92–0.97) and 0.87 (95% CI = 0.63–0.96), respectively. The area under the sROC curves of the ¹⁸F-FDG and ⁶⁸Ga peptides were 0.88 (95% CI = 0.85–0.91) and 0.78 (95% CI = 0.74–0.81), respectively. A subgroup analysis demonstrated that the difference at the per-lesion level and gene mutation level was significant.

Compared to ¹⁸F-FDG PET/CT, the ⁶⁸Ga-somatostatin receptor demonstrated good performance in the localization of metastatic PCs/PGLs, especially those with germline mutations. The use of the ⁶⁸Ga-somatostatin receptor can be a new tool in the diagnosis of metastatic PCs/PGLs.

Although the bismuth breast shield can reduce radiation exposure to the breast during dual-energy computed tomography (DECT), it can potentially affect material quantification on DECT due to artifacts.

To evaluate the effects of bismuth breast shielding on iodine quantification and radiation exposure in DECT.

Small balloons were made with 0.2%, 0.6% and 1.0% blended iodinated contrast (370 mg/mL of iodine) with water. The balloons were located at both anterior and posterior lungs in an adult anthropomorphic chest phantom. DECT was performed with and without breast shielding. Afterwards, iodine concentration values were measured for each balloon on the iodine maps. Absorbed radiation doses in the breast were measured with the optically stimulated luminescence dosimeter.

After shielding, we obtained significantly decreased iodine quantification for all three concentrations with 0.78 ± 0.13 to 0.46 ± 0.13 mg/mL, 2.31 ± 0.17 to 1.68 ± 0.19 mg/mL, and 3.82 ± 0.10 to 2.84 ± 0.20 mg/mL at the anterior location, and 0.72 ± 0.11 to 0.48 ± 0.09 mg/mL, 2.24 ± 0.13 to 1.87 ± 0.21 mg/mL, and 3.75 ± 0.16 to 3.15 ± 0.14 mg/mL at the posterior location for the 0.2%, 0.6%, and 1.0% balloons, respectively (P = 0.001 for all). After shielding, absorbed radiation doses to the breast significantly decreased by 14.8% (4.32 ± 0.33 to 3.68 ± 0.30 mGy; P = 0.005).

Although using the bismuth breast shield may decrease radiation exposure to the breast on DECT, it may also significantly affect iodine quantification.

Increased pulmonary blood flow (PBF) and shear stress may provoke irreversible vascular remodeling, yet invasive visualization of the microvasculature complicates monitoring. A non-invasive imaging methodology would therefore safely provide mechanistic insights into the progression of high PBF-induced vascular remodeling.

To establish a novel microvasculature visualization method using synchrotron radiation pulmonary microangiography (SRPA) that can also calculate PBF velocity in vivo.

A high PBF rat model was established by making a fistula between the abdominal aorta and inferior vena cava. After eight weeks, SRPA was performed and the dynamic density changes in the right lower pulmonary artery (PA) were calculated by software. SRPA was performed with a HARP (High-Gain Avalanche Rushing amorphous Photoconductor) receiver. PBF velocity was calculated by contrast medium transit time within the PA. All data were presented as mean ± standard error (SE). Student's t-test was used for comparison between the two groups.

High dynamic spatial and contrast resolution from SRPA in the PA allowed for clear pulmonary microangiography and accurate detection of higher PBF in the rat model (82.3 ± 8.5 mm/s high-PBF group vs. 46.1 ± 4.3 mm/s control group, P < 0.01).

These novel results demonstrate that SRPA was useful in both visualizing the dynamic flow distribution within the microvasculature and calculating PBF velocity. This newly developed, non-invasive technology may become a powerful tool in clarifying the mechanism of vascular remodeling associated with high PBF-induced shear stress.

18F-fluorodeoxyglucose

*Equal contributors.

To investigate the physiological uptake of 18F-FDG in the vertebral bone marrow in healthy adults on PET/CT imaging, and correlate the appearance with clinical factors including gender, body mass index, and age.

A total of 64 healthy individuals underwent PET/CT scan, and for each vertebral body, the mean and maximum standardized uptake value (SUVmean and SUVmax) were determined in the central slice of vertebral body on the transversal fused PET/CT image. For each individual, the FDG uptake of the four regions was obtained by averaging the SUVmean and SUVmax of the vertebrae in individual regions.

The FDG uptake from thoracic to sacral vertebrae showed an upward trend first, then a downward trend, while that of cervical vertebrae was relatively stable. The SUVmax and SUVmean values of bone marrow in the old group (age ≥ 50 years) were significantly lower than those in the young group (age < 50 years) in all regions of the spine (P < 0.05). FDG uptake of the whole spine showed significant negative correlation with age, and the strongest correlation was observed in lumbar spine (SUVmean: r = −0.364, P < 0.05; SUVmax: r = −0.344, P < 0.05).

FDG uptake showed a tendency to increase first then decrease from thoracic to sacral vertebrae while the tendency was not obvious in cervical vertebrae. In addition, the glycolytic metabolism of all the four regions decreased with advancing age.

Carpal tunnel syndrome (CTS) is the most common peripheral compression neuropathy of the upper extremity. Recently, dynamic ultrasound (US) imaging has shown differences in median nerve mobility between the affected and unaffected sides in CTS.

The present study was performed to compare the median nerve mobility between patients with CTS and healthy individuals, and to correlate median nerve mobility with the severity of CTS.

A total of 101 patients (128 wrists) with CTS and 43 healthy individuals (70 wrists) were evaluated. Electrodiagnostic studies were initially conducted to determine the neurophysiological grading scale (NGS). The cross-sectional area (CSA) of the median nerve and the grade of median nerve mobility were measured using US.

The mean grade of median nerve mobility in the CTS group (1.9) was significantly lower than that in the control group (2.6; P < 0.001). There were significant negative correlations between the grade of median nerve mobility and distal motor latency of the median nerve (r = –0.218, P = 0.015), NGS (r = –0.207, P = 0.020) and CSA of the median nerve (r = –0.196, P = 0.028).

The grade of median nerve mobility was negatively correlated with the severity of CTS. US assessment of median nerve mobility may be useful in diagnosing and determining the severity of CTS.

Computed tomography (CT) can be used to assess the rotational alignment of prosthesis components to identify possible underlying causes of symptomatic total knee arthroplasty (TKA). The use of cone beam computed tomography (CBCT) for the imaging of extremities is relatively new, although it has been widely used in dental imaging.

To assess the intra- and inter-observer reproducibility of CBCT, as well as to validate CBCT for TKA component and periprosthetic bone diagnostics.

CBCT scans were performed on 18 patients the day before a scheduled revision TKA, from which the intra- and inter-observer reproducibility were assessed. Component rotation and loosening were evaluated. Perioperative bone defects were classified.

The inter-observer intraclass coefficient correlation (ICC) for femoral component rotation was 0.41 (95% confidence interval [CI] = 0.12–0.69). For the tibial component, the ICC was 0.87 (95% CI = 0.74–0.94). Intra-observer reproducibilities were 0.70 (95% CI = 0.35–0.87) and 0.92 (95% CI = 0.80–0.97), respectively. The sensitivity for tibial component loosening was 97% and the specificity was 85%. The reliability of bone defect classification was only weak to moderate.

Two-dimensional (2D) CBCT scanning provides reliable and reproducible data for determining the rotation of femoral and tibial components, while showing minor overestimation of tibial component loosening. CBCT is a promising new tool for the evaluation of symptomatic knee arthroplasty patients, with a substantially lower radiation dose compared to conventional 2D multi-slice CT.

Compared with other available injection techniques for lumbar transforaminal epidural steroid injections (LTFESIs), the traditionally performed subpedicular approach is associated with a higher risk of spinal cord infarction, a rare but catastrophic complication.

To assess the short-term efficacy of the retroneural approach for computed tomography (CT)-guided LTFESIs with respect to different needle-tip positions.

This retrospective analysis included 238 patients receiving 286 CT-guided LTFESIs from January 2013 to January 2016. Short-term outcomes in terms of pain relief were assessed using the visual analogue scale (VAS) at baseline and 30 min after. The needle-tip location was categorized as extraforaminal, junctional, or foraminal relative to the neural foramen. Additionally, the distance from the needle tip to the nerve root was measured.

A mean pain reduction of 3.22 points (±2.17 points) on the VAS was achieved. The needle-tip location was extraforaminal in 48% (136/286), junctional in 42% (120/286), and foraminal in 10% (28/286) of the cases. The mean distance from the needle tip to the nerve root was 3.83 mm (±3.37 mm). There was no significant correlation between pain relief and needle-tip position in relation to the neural foramen. Therapy success was not dependent on the distance between the needle tip and the nerve root. No major complications were observed.

In our population treated with LTFESIs, the retroneural approach was shown to be an effective technique, with no significant differences in pain relief following different needle-tip positions.

Testicular microlithiasis (TML) is thought to cause microstructural changes in the parenchyma of the testis, but it is difficult to demonstrate this by ultrasonography. It may be possible to evaluate microstructural changes in the testis by Acoustic Radiation Force Impulse (ARFI) elastography, which measures tissue stiffness.

To assess the tissue stiffness of testicles of children with TML and to compare them with the healthy control group.

Between November 2015 and May 2016, 25 pediatric patients with TML and 24 healthy children were enrolled in the study (mean age for TML and control group 6.7 ± 3.17 and 7.9 ± 4.18 years, respectively). Testicular volumes and mean shear wave velocity (SWV) values were calculated and compared with each other in both groups.

There was no significant difference in average testicular volumes between the TML group and the control group (1.14 cm³, 1.21 cm³, respectively; P = 0.986). Mean SWV of the testicles with TML and normal testicles with control group was 1.18 ± 0.22 cm/s and 0.88 ± 0.11 cm/s, respectively. The SWV of the testicles with TML was higher than the normal testicles and this was statistically significant (P < 0.001).

This study has shown that tissue stiffness in patients with TML is increased compared to the normal population. ARFI elastography helps the early detection of microstructural changes in TML and can be used for screening and follow-up.

High b-value diffusion-weighted imaging has application in the detection of cancerous tissue across multiple body sites. Diffusional kurtosis and bi-exponential modeling are two popular model-based techniques, whose performance in relation to each other has yet to be fully explored.

To determine the relationship between excess kurtosis and signal fractions derived from bi-exponential modeling in the detection of suspicious prostate lesions.

This retrospective study analyzed patients with normal prostate tissue (n = 12) or suspicious lesions (n = 13, one lesion per patient), as determined by a radiologist whose clinical care included a high b-value diffusion series. The observed signal intensity was modeled using a bi-exponential decay, from which the signal fraction of the slow-moving component was derived (SFs). In addition, the excess kurtosis was calculated using the signal fractions and ADCs of the two exponentials (KCOMP). As a comparison, the kurtosis was also calculated using the cumulant expansion for the diffusion signal (KCE).

Both K and KCE were found to increase with SFs within the range of SFs commonly found within the prostate. Voxel-wise receiver operating characteristic performance of SFs, KCE, and KCOMP in discriminating between suspicious lesions and normal prostate tissue was 0.86 (95% confidence interval [CI] = 0.85 – 0.87), 0.69 (95% CI = 0.68–0.70), and 0.86 (95% CI = 0.86–0.87), respectively.

In a two-component diffusion environment, KCOMP is a scaled value of SFs and is thus able to discriminate suspicious lesions with equal precision. KCE provides a computationally inexpensive approximation of kurtosis but does not provide the same discriminatory abilities as SFs and KCOMP.