Showing papers in "European Radiology in 2013"

Nephrogenic systemic fibrosis and gadolinium-based contrast media: updated ESUR Contrast Medium Safety Committee guidelines

Abstract: Purpose To update the guidelines of the Contrast Media Safety Committee (CMSC) of the European Society of Urogenital Radiology (ESUR) on nephrogenic systemic fibrosis and gadolinium-based contrast media.

Iterative reconstruction techniques for computed tomography Part 1: technical principles.

Abstract: Objectives To explain the technical principles of and differences between commercially available iterative reconstruction (IR) algorithms for computed tomography (CT) in non-mathematical terms for radiologists and clinicians.

Letter to the Editor re: ESUR prostate MR guidelines

Abstract: We are from a small hospital engaged in a prostatic MR programme on a small scale. We found the guidelines from Jelle O. Barentsz et al. in the April 2012 issue of your journal to be enlightening [1]. However, we found the recommended segmentation model a bit confusing. First, two different models were recommended, both adopted from the European Consensus Meeting in 2010 [2]. One uses 16 regions and the other 27 regions. Similar names in the two different models may mean different sites. For example, 4a would mean right anterior basal tissue in the 16-region model, whereas in the 27-region model, it would mean tissue over the left anterior periphery at the mid-level. Understandingly, individual hospitals can clarify which model is being used or they can report by stating, for example, 4a/16 or 4a/27. It may be better to use a more meaningful and unified nomenclature. The other problem is the left and right convention. Nowadays, most MR machines would normally display the patient’s right on the left side of the monitor screen. This is also true for most transverse and coronal ultrasound images. The same view is shared by surgeons doing transurethral resection and is easy to follow for digital examination even if one is standing at the side of the patient. The models recommended, however, are flipped laterally. There have been very successful segmentation models in the history of medicine. For example, the liver segmentation had been confusing until Couinaud’s intervention [3]. The eight-segment anatomical based liver model is now almost universal, although it took some years to establish. The other example would be the 17 segments for assessment of the left ventricular myocardium recommended by the American Heart Association [4]. The anticlockwise numbering of the three disc sections from base to apex is easy to comprehend. We are looking forward to a more standardized version of the segmentation model of the prostate. In the meantime, we will attempt to use a modification from the 16-region model, flipped and with labels changed to facilitate local communication between the MR radiologist, the ultrasonologist, interventionist and the surgeons. It uses the AP pair to stand for anterior and posterior, respectively; BMX triple for base, mid and apex sections; CS for central and side (peripheral). The letters are chosen to avoid overlap. The 16 segments will be counted from base to apex, from right to left and from anterior to posterior. The anterior basal segments are RAB and LAB. The posterior basal segments are RPBS, RPBC, LPBC and LPBS. The anterior segments for the mid-section are RAM and LAM and the posterior segments are RPMS, RPMC, LPMC and LPMS. For the apex, RAX and LAX are for anterior; RPX and LPX are for posterior. We believe the same strategy can be used for the 27segment model by adding F for fibromuscular stroma, so that there will be FB, FM and FX for the corresponding segments from base to apex. The labelling is then completed by incorporating C or S for each of the other 24 segments.

Influence of imaging and histological factors on prostate cancer detection and localisation on multiparametric MRI: a prospective study

Abstract: To assess factors influencing prostate cancer detection on multiparametric (T2-weighted, diffusion-weighted, and dynamic contrast-enhanced) MRI. One hundred and seventy-five patients who underwent radical prostatectomy were included. Pre-operative MRI performed at 1.5 T (n = 71) or 3 T (n = 104), with (n = 58) or without (n = 117) an endorectal coil were independently interpreted by two radiologists. A five-point subjective suspicion score (SSS) was assigned to all focal abnormalities (FAs). MR findings were then compared with whole-mount sections. Readers identified 192–214/362 cancers, with 130–155 false positives. Detection rates for tumours of 2 cc were 33–45/155 (21–29 %), 15–19/35 (43–54 %) and 8–9/12 (67–75 %) for Gleason ≤6, 17/27 (63 %), 42–45/51 (82–88 %) and 34/35 (97 %) for Gleason 7 and 4/5 (80 %), 13/14 (93 %) and 28/28 (100 %) for Gleason ≥8 cancers respectively. At multivariate analysis, detection rates were influenced by tumour Gleason score, histological volume, histological architecture and location (P < 0.0001), but neither by field strength nor coils used for imaging. The SSS was a significant predictor of both malignancy of FAs (P < 0.005) and aggressiveness of tumours (P < 0.00001). Detection rates were significantly influenced by tumour characteristics, but neither by field strength nor coils used for imaging. The SSS significantly stratified the risk of malignancy of FAs and aggressiveness of detected tumours. • Prostate cancer volume, Gleason score, architecture and location are MRI predictors of detection. • Field strength and coils used do not influence the tumour detection rate. • Multiparametric MRI is accurate for detecting aggressive tumours. • A subjective suspicion score can stratify the risk of malignancy and tumour aggressiveness.

Measurement reproducibility of perfusion fraction and pseudodiffusion coefficient derived by intravoxel incoherent motion diffusion-weighted MR imaging in normal liver and metastases

Abstract: To determine the measurement reproducibility of perfusion fraction f, pseudodiffusion coefficient D * and diffusion coefficient D in colorectal liver metastases and normal liver. Fourteen patients with known colorectal liver metastases were examined twice using respiratory-triggered echo-planar DW-MRI with eight b values (0 to 900 s/mm2) 1 h apart. Regions of interests were drawn around target metastasis and normal liver in each patient to derive ADC (all b values), ADChigh (b values ≥100 s/mm2) and intravoxel incoherent motion (IVIM) parameters f, D * and D by least squares data fitting. Short-term measurement reproducibility of median ADC, ADChigh, f, D * and D values were derived from Bland–Altman analysis. The measurement reproducibility for ADC, ADChigh and D was worst in colorectal liver metastases (−21 % to +25 %) compared with liver parenchyma (−6 % to +8 %). Poor measurement reproducibility was observed for the perfusion-sensitive parameters of f (−75 % to +241 %) and D * (−89 % to +2,120 %) in metastases, and to a lesser extent the f (−24 % to +25 %) and D* (−31 % to +59 %) of liver. Estimates of f and D * derived from the widely used least squares IVIM fitting showed poor measurement reproducibility. Efforts should be made to improve the measurement reproducibility of perfusion-sensitive IVIM parameters. • Quantitative diffusion-weighted MRI parameters are increasingly used for clinical management decisions. • However perfusion-sensitive intravoxel incoherent motion (IVIM) parameters showed poor measurement reproducibility. • Measurement reproducibility of IVIM parameters was worse in metastases than normal liver. • Efforts to improve measurement reproducibility of IVIM parameters should be explored.

Iterative reconstruction techniques for computed tomography part 2: initial results in dose reduction and image quality

Abstract: Objectives To present the results of a systematic literature search aimed at determining to what extent the radiation dose can be reduced with iterative reconstruction (IR) for cardiopulmonary and body imaging with computed tomography (CT) in the clinical setting and what the effects on image quality are with IR versus filtered back-projection (FBP) and to provide recommendations for future research on IR.

Radiofrequency ablation of benign non-functioning thyroid nodules: 4-year follow-up results for 111 patients

Abstract: To evaluate the clinical outcomes and safety of radiofrequency (RF) ablation for benign non-functioning thyroid nodules over a 4-year follow-up. We evaluated 126 benign non-functioning thyroid nodules of 111 patients treated with RF ablation and followed-up more than 3 years. RF ablation was performed using the Cool-Tip RF system and an internally cooled electrode. Nodule volume and cosmetic and symptom scores were evaluated before treatment and during follow-up. Complications and factors related to efficacy were evaluated. The mean follow-up duration was 49.4 ± 13.6 months. Thyroid nodule volume decreased significantly, from 9.8 ± 8.5 ml before ablation to 0.9 ± 3.3 ml (P < 0.001) at final evaluation: a mean volume reduction of 93.4 ± 11.7 %. The mean cosmetic (P < 0.001) and symptom scores (P < 0.001) improved significantly. Factors related to efficacy were initial solidity and volume. The overall recurrence rate was 5.6 % (7/126). The overall complication rate was 3.6 % (4/111). RF ablation was effective in shrinking benign thyroid nodules and in controlling nodule-related problems over a 4-year follow-up. There were no life-threatening complications or sequelae. Therefore, RF ablation can be used as a non-surgical treatment for patients with benign non-functioning thyroid nodules. • Radiofrequency (RF) ablation provides a non-surgical option for benign non-functioning thyroid nodules • RF ablation reduced non-functioning thyroid nodular volume by 93.5 % after 49 months • Initial solidity and volume influenced the efficacy of RF ablation • Larger thyroid nodules required more treatment sessions to achieve appropriate volume reduction • Complete treatment of the periphery of the nodule is important in preventing marginal regrowth

CEM43°C thermal dose thresholds: a potential guide for magnetic resonance radiofrequency exposure levels?

Abstract: Objective To define thresholds of safe local temperature increases for MR equipment that exposes patients to radiofrequency fields of high intensities for long duration. These MR systems induce heterogeneous energy absorption patterns inside the body and can create localised hotspots with a risk of overheating.

Prospective trial comparing full-field digital mammography (FFDM) versus combined FFDM and tomosynthesis in a population-based screening programme using independent double reading with arbitration

Abstract: To compare double readings when interpreting full field digital mammography (2D) and tomosynthesis (3D) during mammographic screening. A prospective, Ethical Committee approved screening study is underway. During the first year 12,621 consenting women underwent both 2D and 3D imaging. Each examination was independently interpreted by four radiologists under four reading modes: Arm A—2D; Arm B—2D + CAD; Arm C—2D + 3D; Arm D—synthesised 2D + 3D. Examinations with a positive score by at least one reader were discussed at an arbitration meeting before a final management decision. Paired double reading of 2D (Arm A + B) and 2D + 3D (Arm C + D) were analysed. Performance measures were compared using generalised linear mixed models, accounting for inter-reader performance heterogeneity (P < 0.05). Pre-arbitration false-positive scores were 10.3 % (1,286/12,501) and 8.5 % (1,057/12,501) for 2D and 2D + 3D, respectively (P < 0.001). Recall rates were 2.9 % (365/12,621) and 3.7 % (463/12,621), respectively (P = 0.005). Cancer detection was 7.1 (90/12,621) and 9.4 (119/12,621) per 1,000 examinations, respectively (30 % increase, P < 0.001); positive predictive values (detected cancer patients per 100 recalls) were 24.7 % and 25.5 %, respectively (P = 0.97). Using 2D + 3D, double-reading radiologists detected 27 additional invasive cancers (P < 0.001). Double reading of 2D + 3D significantly improves the cancer detection rate in mammography screening. • Tomosynthesis-based screening was successfully implemented in a large prospective screening trial. • Double reading of tomosynthesis-based examinations significantly reduced false-positive interpretations. • Double reading of tomosynthesis significantly increased the detection of invasive cancers.

Computed tomography of the chest with model-based iterative reconstruction using a radiation exposure similar to chest X-ray examination: preliminary observations.

Abstract: Objectives The purpose of this study was to assess the diagnostic image quality of ultra-low-dose chest computed tomography (ULD-CT) obtained with a radiation dose comparable to chest radiography and reconstructed with filtered back projection (FBP), adaptive statistical iterative reconstruction (ASIR) and model-based iterative reconstruction (MBIR) in comparison with standard dose diagnostic CT (SDD-CT) or low-dose diagnostic CT (LDD-CT) reconstructed with FBP alone.

Embolisation of prostatic arteries as treatment of moderate to severe lower urinary symptoms (LUTS) secondary to benign hyperplasia: results of short- and mid-term follow-up

Abstract: Objectives To evaluate the short- and medium-term results of prostatic arterial embolisation (PAE) for benign prostatic hyperplasia (BPH).

The efficiency of acoustic radiation force impulse imaging for the staging of liver fibrosis: a meta-analysis.

Abstract: Objectives Acoustic radiation force impulse (ARFI) imaging is an ultrasound-based elastography method that is integrated into a conventional ultrasound machine. A meta-analysis based on original and abstract publications was performed to evaluate the overall performance of ARFI for the diagnosis of liver fibrosis.

The second ESGAR consensus statement on CT colonography

Abstract: Objective To update quality standards for CT colonography based on consensus among opinion leaders within the European Society of Gastrointestinal and Abdominal Radiology (ESGAR)

Stiffness of tumours measured by shear-wave elastography correlated with subtypes of breast cancer

Abstract: To evaluate the correlation between stiffness values obtained by shear-wave elastography (SWE) and breast cancer subtypes. This was an institutional review board-approved retrospective study with a waiver of informed consent. The stiffness of 337 invasive breast cancers in 337 women was evaluated by SWE and mean stiffness values (kPa) and qualitative colour scores (1–5) of tumours were obtained. The results were analysed according to BI-RADS category, tumour size, grade and tumour subtype (triple-negative [TN], human epidermal growth factor receptor 2 [HER2]-positive, and oestrogen receptor [ER]-positive) using a multiple linear regression analysis. The mean stiffness values and colour scores were: 146.8 kPa ± 57.0 and 4.1 ± 1.1; 165.8 kPa ± 48.5 and 4.6 ± 0.7 for TN tumours (n = 64), 160.3 kPa ± 56.2 and 4.3 ± 1.0 for HER2-positive tumours (n = 55) and 136.9 kPa ± 57.2 and 4.0 ± 1.1 for ER-positive tumours (n = 218; P < 0.0001). All three breast cancers classified as BI-RADS category 3 on B-mode ultrasound were TN subtype. A multiple linear regression analysis revealed that tumour size, histological grade and tumour subtype were independent factors that influenced the stiffness values. High stiffness values correlated with aggressive subtypes of breast cancer. • Shear-wave elastography is increasingly used to measure the stiffness of breast tumours. • Triple-negative and HER2-positive tumours showed greater stiffness than ER-positive tumours. • All breast cancers classified as BI-RADS 3 on B-mode ultrasound were triple-negative subtype. • Tumour size, histological grade and subtype were independent factors influencing SWE stiffness.

Accuracy of CT angiography in the diagnosis of acute gastrointestinal bleeding: systematic review and meta-analysis.

Abstract: To assess the diagnostic accuracy of computed tomography (CT) angiography in the evaluation of patients with an episode of acute gastrointestinal haemorrhage. Systematic review and meta-analysis to estimate pooled accuracy indices. A bivariate random effects model was adjusted to obtain a summary receiver-operating characteristic (sROC) curve and the corresponding area under the curve (AUC). Twenty-two studies were included and provided data on 672 patients (range of age 5–74) with a mean age of 65 years. The overall sensitivity of CT angiography for detecting active acute GI haemorrhage was 85.2 % (95 % CI 75.5 % to 91.5 %). The overall specificity of CT angiography was 92.1 % (95 % CI 76.7 % to 97.7 %). The likelihood ratios for positive and negative test results were 10.8 (95 % CI 3.4 to 34.4) and 0.16 (95 % CI 0.1 to 0.27) respectively, with an AUC of 0.935 (95 % CI 0.693 to 0.989). The sources of heterogeneity explored had no significant impact on diagnostic performance. CT shows high diagnostic accuracy and is an excellent diagnostic tool for detection and localising of intestinal bleeding sites. It is highly available, provides fast detection and localisation of the bleeding site, and is minimally invasive. • CT angiography is increasingly used for investigating severe gastrointestinal bleeding. • This systematic review and meta-analysis updates previous ones. • In patients with massive gastrointestinal bleeding, CT angiography/MDCT detects bleeding accurately. • CT angiography is useful in locating the bleeding site and determining appropriate treatment.

How to differentiate benign from malignant myometrial tumours using MR imaging.

Abstract: To retrospectively evaluate the ability of magnetic resonance imaging (MRI) to differentiate malignant from benign myometrial tumours. Fifty-one women underwent MRI before surgery for evaluation of a solitary myometrial tumour. At histopathology, there were 25 uncertain or malignant mesenchymal tumours and 26 benign leiomyomas. Conventional morphological MRI criteria were recorded in addition to b 1,000 signal intensity and apparent diffusion coefficient (ADC). Odds ratios (OR) were calculated for each criterion. A multivariate analysis was performed to construct an interpretation model. The significant criteria for prediction of malignancy were high b 1,000 signal intensity (OR = +∞), intermediate T2-weighted signal intensity (OR = +∞), mean ADC (OR = 25.1), patient age (OR = 20.1), intra-tumoral haemorrhage (OR = 21.35), endometrial thickening (OR = 11), T2-weighted signal heterogeneity (OR = 10.2), menopausal status (OR = 9.7), heterogeneous enhancement (OR = 8) and non-myometrial origin on MRI (OR = 4.9). In the recursive partitioning model, using b 1,000 signal intensity, T2 signal intensity, mean ADC, and patient age, the model correctly classified benign and malignant tumours in 47 of the 51 cases (92.4 %). We have developed an interpretation model usable in routine practice for myometrial tumours discovered at MRI including T2 signal, b 1,000 signal and ADC measurement. • MRI is widely used to differentiate benign from malignant myometrial tumours. • By combining T2-weighted, b 1,000 and ADC features, MRI is 92.4 % accurate. • DWI may limit misdiagnoses of uterine sarcoma as benign leiomyoma. • Patient age is important when considering a solitary myometrial tumour.

Image quality of ultra-low radiation exposure coronary CT angiography with an effective dose <0.1 mSv using high-pitch spiral acquisition and raw data-based iterative reconstruction

Abstract: Objectives We evaluated the potential of prospectively ECG-triggered high-pitch spiral acquisition with low tube voltage and current in combination with iterative reconstruction to achieve coronary CT angiography with sufficient image quality at an effective dose below 0.1 mSv.

Prostate cancer recurrence after radical prostatectomy: the role of 3-T diffusion imaging in multi-parametric magnetic resonance imaging

Abstract: To validate the role of 3-T diffusion-weighted imaging (DWI) in the detection of local prostate cancer recurrence after radical prostatectomy (RP). T2-weighted imaging, DWI and dynamic contrast-enhanced MRI (DCE-MRI) were performed with a 3-T magnet in 262 patients after RP. Twenty out of 262 patients evaluated were excluded. MRI results were validated by prostate-specific antigen (PSA) reduction after external beam radiotherapy in group A (126 patients, local recurrence size range 4–8 mm) and by transrectal ultrasound biopsy in group B (116 patients, local recurrence size range 9–15 mm). In group A combined T2-weighted and DCE-MRI (T2+DCE) shows 98 % sensitivity, 94 % specificity and 93 % accuracy in identifying local recurrence; combined T2-weighted and DWI with a b value of 3,000 s/mm2 (T2+DW3) displays 97 % sensitivity, 95 % specificity and 92 % accuracy, while with a b value of 1,000 s/mm2 (T2+DW1) affords 93 % sensitivity, 89 % specificity and 88 % accuracy. In group B T2+DCE shows 100 % sensitivity, 97 % specificity and 91 % accuracy in detecting local cancer recurrence; T2+DW3 displays 98 % sensitivity, 96 % specificity and 89 % accuracy; T2+DW1 has 94 % sensitivity, 92 % specificity and 86 % accuracy. DCE-MRI is the most reliable technique in detecting local prostate cancer recurrence after RP, though DWI can be proposed as a reliable alternative. • Diffusion-weighted magnetic resonance imaging (DWI-MRI) is being increasingly used in oncology. • PSA analysis does not distinguish prostate cancer recurrence from distant metastasis. • DWI-MR can diagnose local prostate cancer recurrence after radical prostatectomy. • DWI-MR is almost comparable to DCE-MRI in detecting local recurrence.

Potentially relevant incidental findings on research whole-body MRI in the general adult population: frequencies and management

Abstract: Objectives To report the frequencies of potentially relevant incidental findings in the general adult population and to develop a protocol for their management in whole-body magnetic resonance imaging (wb-MRI).

Diffusion-weighted MR imaging in primary rectal cancer staging demonstrates but does not characterise lymph nodes

Abstract: Objectives To evaluate the performance of diffusion-weighted MRI (DWI) for the detection of lymph nodes and for differentiating between benign and metastatic nodes during primary rectal cancer staging.

Distinguishing enhancing from nonenhancing renal masses with dual-source dual-energy CT: iodine quantification versus standard enhancement measurements

Abstract: To compare the diagnostic accuracy of iodine quantification and standard enhancement measurements in distinguishing enhancing from nonenhancing renal masses. The Institutional Review Board approved this retrospective study conducted from data found in institutional patient databases and archives. Seventy-two renal masses were characterised as enhancing or nonenhancing using standard enhancement measurements (in HU) and iodine quantification (in mg/ml). Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of standard enhancement measurements and iodine quantification were calculated from χ 2 tests of contingency with histopathology or imaging follow-up as the reference standard. Difference in accuracy was assessed by means of McNemar analysis. Sensitivity, specificity, PPV, NPV and diagnostic accuracy for standard enhancement measurements and iodine quantification were 77.7 %, 100 %, 100 %, 81.8 %, 89 % and 100 %, 94.4 %, 94.7, 100 % and 97 %, respectively. The McNemar analysis showed that the accuracy of iodine quantification was significantly better (P < 0.001) than that of standard enhancement measurements. Compared with standard enhancement measurements, whole-tumour iodine quantification is more accurate in distinguishing enhancing from nonenhancing renal masses. • Enhancement of renal lesions is important when differentiating benign from malignant tumours. • Dual-energy CT offers measurement of iodine uptake rather than mere enhancement values. • Whole-tumour iodine quantification seems more accurate than standard CT enhancement measurements.

Initial experience with single-source dual-energy CT abdominal angiography and comparison with single-energy CT angiography: image quality, enhancement, diagnosis and radiation dose

Abstract: To assess image quality of virtual monochromatic spectral (VMS) images, compared to single-energy (SE) CT, and to evaluate the feasibility of material density imaging in abdominal aortic disease. In this retrospective study, single-source (ss) dual-energy (DE) CT of the aorto-iliac system in 35 patients (32 male, mean age 76.5 years) was compared to SE-CT. By post-processing the data from ssDECT, VMS images at different energies and material density water (WD) images were generated. The image quality parameters were rated on 5-point scales. The aorto-iliac attenuation and contrast-to-noise ratio (CNR) were recorded. Quality of WD images was compared to true unenhanced (TNE) images. Radiation dose was recorded and statistical analysis was performed. Image quality and noise were better at 70 keV (P < 0.01). Renal artery branch visualisation was better at 50 keV (P < 0.005). Attenuation and CNR were higher at 50 and 70 keV (P < 0.0001). The WD images had diagnostic quality but higher noise than TNE images (P < 0.0001). Radiation dose was lower using single-phase ssDECT compared to dual-phase SE-CT (P < 0.0001). 70-keV images from ssDECT provide higher contrast enhancement and improved image quality for aorto-iliac CT when compared to SE-CT at 120 kVp. WD images are an effective substitute for TNE images with a potential for dose reduction. • Multi-detector computed tomography (MDCT) angiography is now a routine procedure. • Single-source dual-energy CT (ssDECT) can provide simultaneous data with different kilovoltages. • 70 keV images showed better image quality than conventional single-energy (SE) CT. • 70 keV images exhibited less image noise in comparison to SE-CT.

Endovascular treatment of brain arteriovenous malformations using a liquid embolic agent: results of a prospective, multicentre study (BRAVO).

Abstract: To evaluate the safety and efficacy of a new liquid embolic agent in brain arteriovenous malformation (bAVMs) embolisation A prospective, multicentre series was conducted at 11 interventional centres in Europe to evaluate embolisation of bAVMs with the new liquid embolic agent Technical conditions, complications, clinical outcome and anatomical results were independently analysed From December 2005 to December 2008, 117 patients (72 male; 45 female, aged 18–75 years) were included Clinical presentation was mostly haemorrhage (342 %) and seizures (282 %) Most AVMs were located in the brain hemispheres (855 %) AVMs were <3 cm in 521 % of patients and ≥3 cm in 479 % Morbidity was observed in 6/117 patients (51 %), related to haemorrhagic events in 2 cases and non-haemorrhagic complications in 4 cases Five patients (43 %) died in relation to the treatment (bleeding in 4 patients and extensive venous thrombosis in 1) Complete occlusion of the AVM by embolisation alone was obtained in 235 % of patients Complementary treatment was performed in 823 % of patients with partial AVM occlusion, mostly radiosurgery In this prospective, multicentre, European, observational series, the new liquid embolic agent proved to be suitable for BAVM embolisation, with acceptable morbidity and mortality and good efficacy • Numerous interventional techniques have been used to embolise brain arteriovenous malformations (AVMs) • This prospective multicentre study demonstrates the suitability of a liquid embolic agent • The safety of treatment using Onyx is acceptable • Such embolisation leads to complete AVM occlusion in 235 % of patients

Texture analysis of advanced non-small cell lung cancer (NSCLC) on contrast-enhanced computed tomography: prediction of the response to the first-line chemotherapy

Abstract: To assess whether tumour heterogeneity, quantified by texture analysis (TA) on contrast-enhanced computed tomography (CECT), can predict response to chemotherapy in advanced non-small cell lung cancer (NSCLC). Fifty-three CECT studies of patients with advanced NSCLC who had undergone first-line chemotherapy were retrospectively reviewed. Response to chemotherapy was evaluated according to RECIST1.1. Tumour uniformity was assessed by a TA method based on Laplacian of Gaussian filtering. The resulting parameters were correlated with treatment response and overall survival by multivariate analysis. Thirty-one out of 53 patients were non-responders and 22 were responders. Average overall survival was 13 months (4–35), minimum follow-up was 12 months. In the adenocarcinoma group (n = 31), the product of tumour uniformity and grey level (GL*U) was the unique independent variable correlating with treatment response. Dividing the GL*U (range 8.5-46.6) into tertiles, lesions belonging to the second and the third tertiles had an 8.3-fold higher probability of treatment response compared with those in the first tertile. No association between texture features and response to treatment was observed in the non-adenocarcinoma group (n = 22). GL*U did not correlate with overall survival. TA on CECT images in advanced lung adenocarcinoma provides an independent predictive indicator of response to first-line chemotherapy. • Contrast enhanced computed tomography is currently used to stage lung cancer. • Texture analysis allows tumour heterogeneity to be quantified on CT images. • Texture parameters seem to predict chemotherapy response in advanced NSCLC.

The value of apparent diffusion coefficient in the assessment of cervical cancer

Abstract: To evaluate the potential value of apparent diffusion coefficient (ADC) measurement in the assessment of cervical cancer. One hundred twelve patients with cervical cancer and 67 control subjects underwent diffusion-weighted imaging (DWI) in addition to routine MR imaging at 3.0-T MRI before therapy. All ADCs were calculated from b = 0, 600 s/mm2 and b = 0, 1,000 s/mm2. The ADCs of cervical cancer were significantly lower than those of normal cervix for both ADC maps. There was a statistically significant difference between the ADCs of well-/moderately differentiated (G1/2) tumours and poorly differentiated (G3) tumours, between the ADCs of squamous cell carcinoma and adenocarcinoma, between the pretherapy ADCs of tumour recurrence or metastasis and tumour free patients after radical hysterectomy for both ADC maps. There was no significant difference among the ADCs of cervical cancer when divided by other features (FIGO, lymph node status, tumour size and age groups) for both ADC maps. ADC values were reliable for differentiating cervical cancer from normal cervix with high diagnostic accuracy. The ADCs can be used to indicate the degree and histological type of cervical cancer, although there is some overlap. G3 tumours and lower ADCs may indicate poor prognosis. The diagnostic accuracy was equal for both ADC maps. • Diffusion-weighted magnetic resonance imaging provides new information about cervical cancer • Apparent diffusion coefficient values can differentiate cervical cancer from normal cervical tissue • Pretherapy ADCs can also predict the prognosis for patients who have undergone radical hysterectomy • ADCs can help indicate the degree and histological type of cervical cancer • Patients with G3 tumours and lower ADCs may benefit from preoperative chemoradiation

Optimal threshold in CT quantification of emphysema

Abstract: To determine the optimal threshold by quantitatively assessing the extent of emphysema at the level of the entire lung and at the level of individual lobes using a large, diverse dataset of computed tomography (CT) examinations. This study comprises 573 chest CT examinations acquired from subjects with different levels of airway obstruction (222 none, 83 mild, 141 moderate, 63 severe and 64 very severe). The extent of emphysema was quantified using the percentage of the low attenuation area (LAA%) divided by the total lung or lobe volume(s). The correlations between the extent of emphysema, and pulmonary functions and the five-category classification were assessed using Pearson and Spearman’s correlation coefficients, respectively. When quantifying emphysema using a density mask, a wide range of thresholds from −850 to −1,000 HU were used. The highest correlations of LAA% with the five-category classification and PFT measures ranged from −925 to −965 HU for each individual lobe and the entire lung. However, the differences between the highest correlations and those obtained at −950 HU are relatively small. Although there are variations in the optimal cut-off thresholds for individual lobes, the single threshold of −950 HU is still an acceptable threshold for density-based emphysema quantification. • CT is widely used to assess the severity of emphysema • Density mask technique helps clinicians assess the extent of emphysema with CT • A standardised cut-off for density mask analysis at lobe level is desirable • −950 HU is acceptable for density-based emphysema quantification at the lobar level

Differentiation of benign from malignant solid breast masses: comparison of two-dimensional and three-dimensional shear-wave elastography

Abstract: To prospectively compare the diagnostic performances of two-dimensional (2D) and three-dimensional (3D) shear-wave elastography (SWE) for differentiating benign from malignant breast masses. B-mode ultrasound and SWE were performed for 134 consecutive women with 144 breast masses before biopsy. Quantitative elasticity values (maximum and mean elasticity in the stiffest portion of mass, Emax and Emean; lesion-to-fat elasticity ratio, Erat) were measured with both 2D and 3D SWE. The area under the receiver operating characteristic curve (AUC), sensitivity and specificity of B-mode, 2D, 3D SWE and combined data of B-mode and SWE were compared. Sixty-seven of the 144 breast masses (47 %) were malignant. Overall, higher elasticity values of 3D SWE than 2D SWE were noted for both benign and malignant masses. The AUC for 2D and 3D SWE were not significantly different: Emean, 0.938 vs 0.928; Emax, 0.939 vs 0.930; Erat, 0.907 vs 0.871. Either 2D or 3D SWE significantly improved the specificity of B-mode ultrasound from 29.9 % (23 of 77) up to 71.4 % (55 of 77) and 63.6 % (49 of 77) without a significant change in sensitivity. Two-dimensional and 3D SWE performed equally in distinguishing benign from malignant masses and both techniques improved the specificity of B-mode ultrasound. • Shear-wave elastography (SWE) is increasingly used during ultrasound of the breast • 2D and 3D SWE performed equally in distinguishing benign from malignant masses • Either SWE method, combined with B-mode, outperformed B-mode ultrasound alone • Quantitative elasticity was greater for 3D than 2D SWE for all masses

Inter-reader agreement of the ESUR score for prostate MRI using in-bore MRI-guided biopsies as the reference standard.

Abstract: The recent European Society of Urogenital Radiology (ESUR) guidelines for evaluation and reporting of prostate multiparametric magnetic resonance imaging (mp-MRI) include the Prostate Imaging Reporting and Data System (PI-RADS). The aim of this study was to investigate the inter-reader agreement of this scoring system. One hundred and sixty-four lesions in 67 consecutive patients with elevated prostate-specific antigen and previously negative trans-rectal ultrasound (TRUS)-guided biopsy were scored retrospectively by three blinded readers using PI-RADS. Mp-MRI was performed at 3 T using T2-weighted, diffusion-weighted and dynamic contrast-enhanced imagings (T2WI, DWI, DCE-MRI). Histology of all lesions was obtained by in-bore MRI-guided biopsy. Cohen’s kappa statistics were calculated for all readers. Inter-reader agreement for all lesions was good to moderate (T2WI, κ = 0.55; DWI, κ = 0.64; DCE-MRI, κ = 0.65). For tumour lesions it was good (T2WI, κ = 0.66; DWI, κ = 0.80; DCE-MRI, κ = 0.63) and for benign lesions moderate to good (T2WI, κ = 0.46; DWI, κ = 0.52; DCE-MRI, κ = 0.67). Using an overall PI-RADS score with a threshold of ≥10, we achieved a sensitivity of 85.7 %, and negative predictive value of 90.1 % for biopsied lesions. PI-RADS score shows good to moderate inter-reader agreement and enables standardised evaluation of prostate mp-MRI, with high sensitivity and negative predictive value. • The European Society of Urogenital Radiology recently published guidelines for prostate MRI. • We have evaluated inter-reader agreement of ESUR scoring for multiparametric prostate MRI. • PI-RADS shows good to moderate inter-reader agreement and is clinically applicable. • PI-RADS achieves in our series high sensitivity and negative predictive value for biopsied lesions. • PI-RADS can be used as standardised scoring system in prostate cancer detection.

Quantitative assessment of shear-wave ultrasound elastography in thyroid nodules: diagnostic performance for predicting malignancy

Abstract: To evaluate the predictability of shear-wave ultrasound elastography (SWE) for thyroid malignancy and to compare the diagnostic performances of SWE and B-mode US. Retrospective review of 99 patients who underwent SWE before US-guided fine-needle aspiration of thyroid nodules was performed. SWE elasticity indices of the mean (Emean ), maximum (Emax), and minimum (Emin) of nodules were measured. Diagnostic performance of SWE was compared with that of B-mode US. Among a total of 99 nodules, 21 were papillary thyroid carcinoma (PTC) and 78 were benign. Emean, Emax, and Emin were significantly higher in PTCs than in benign nodules (P < 0.001). Sensitivity and specificity for predicting malignancy were 76.1 %, 64.1 % with Emax (65 kPa), 61.9 %, 76.1 % with Emin (53 kPa), and 66.6 %, 71.6 % with Emean (62 kPa). Areas under the ROC curves (Az) of SWE values were not significantly different from those of US categories on B-mode US. However, combining Emean and Emin with B-mode US of probably benign lesions improved the specificity (P = 0.02, 0.007) for predicting PTC. The quantitative parameter of SWE was significantly higher in PTC than in benign nodules, and combined use of quantitative SWE and B-mode US provided higher specificity for predicting malignancy. • Quantitative shear-wave elastography (SWE) helps differentiate benign from malignant nodules • SWE and conventional ultrasound have comparable diagnostic performance for predicting thyroid malignancy • Combined quantitative SWE and B-mode ultrasound is highly specific for thyroid malignancy

Combined contrast-enhanced magnetic resonance and diffusion-weighted imaging reading adapted to the "Breast Imaging Reporting and Data System" for multiparametric 3-T imaging of breast lesions.

Abstract: Objective To develop and assess a combined reading for contrast-enhanced magnetic resonance (CE-MRI) and diffusion weighted imaging (DWI) adapted to the BI-RADS for multiparametric MRI of the breast at 3 T.