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Introduction Digital Mammography (DM-2D) and more recently Digital Breast Tomosynthesis (DBT), are two of the most effective imaging modalities for breast cancer detection, often used in screening programmes. It may happen that exams using these two imaging modalities are inadvertently performed to pregnant women. The objective of this study is to assess the dose in the uterus due to DM-2D and DBT exams, according to two main irradiation scenarios: in the 1st scenario the exposure parameters were pre-selected directly by the imaging system, while in the 2nd scenario, the maximum exposure parameters were chosen. Methods The mammography equipment used was a Siemens Mammomat Inspiration. A physical anthropomorphic phantom, PMMA plates (simulating a breast thickness of 6 cm) and thermoluminescent dosimeters (TLDs) were used to measure entrance air kerma values on the phantom's breast and abdomen in order to successively estimate the mean glandular dose (MGD) and the dose in the uterus. For the two irradiation scenarios chosen, two-breast imaging modalities were selected: 1) DBT in Cranio-Caudal (CC) view (with 28 kV and 160 mAs as exposure parameters), 2) DBT and DM in Medio Lateral-Oblique (MLO) and CC views (with 34 kV and 250 mAs as exposure parameters). Results In the 1st scenario, the TLD measurements did not detect significant dose values in the abdomen whereas the MGD estimated using the D.R. Dance model was in close agreement with data available in the literature. In the 2nd scenario, there was no significant difference in MGD estimation between the different views, whereas the air kerma values in the abdomen (in DBT mode, CC and MLO) were 0.049 mGy and 0.004 mGy respectively. In CC DM-2D mode the abdomen air kerma value was 0.026 mGy, with no significant detected value in MLO view. Conclusions For the dose in the uterus, the obtained values seem to indicate that DM-2D and DBT examinations inadvertently performed during pregnancy do not pose a significant radiological risk, even considering the case of overexposure in both breasts. Implications for practice The accurate knowledge of the doses in DM-2D and DBT will contribute to raise the awareness among medical practitioners involved in breast imaging empowering them to provide accurate information about dose levels in the uterus, improving their radiation risk communication skills and consequently helping to reduce the anxiety of pregnant women undergoing this type of examinations.

The early detection of breast cancer has been shown to reduce deaths through randomized, controlled trials. Numerous observational studies, failure analyses, and "incidence of death" studies have confirmed that screening reduces deaths in the general population. Digital Breast Tomosynthesis (DBT) which collects mammographic images from different angles and uses them to synthesize planes through the breast is simply another advance in mammography among others that have been made over the years. DBT "absolutely" detects more cancers at a time when cure is more likely while also having the advantage of reducing recall rates. The Tomosynthesis Mammographic Imaging Screening Trial (TMIST) has been designed to compare DBT with 2-Dimensional Full Field Digital Mammography (FFDM), but it's major design issues may provide misleading results. Instead of using a reduction in deaths as the endpoint, benefit in TMIST is predicated on a reduction in advanced cancers in the DBT group. This is a questionable "endpoint" (a reduction in advanced cancers is not necessary as proof of benefit). In addition, the trial may be underpowered so that even if DBT shows a benefit it may not be able to achieve "statistical significance". The six CISNET models of the National Cancer Institute have shown that annual mammography beginning at the age of 40 will save the most lives. Yet TMIST will only include women ages 45 and over and will screen postmenopausal women every two years instead of annually. Consequently, TMIST results may be used, inappropriately, to limit access to breast cancer screening starting at the age of 45, and only offer biennial screening for post-menopausal women.

Background We aimed to compare radiographic and digital tomosynthesis assessments of early biological fixation of a cementless stem in primary total hip arthroplasty and to investigate the factors associated with early biological fixation. Methods Seventy-three patients underwent total hip arthroplasty using cementless short tapered-wedge stems. Both radiography and digital tomosynthesis were performed at 6 weeks and 3, 6, 12, and 24 months after surgery. The presence of spot welds (SW) was evaluated at each postoperative period to assess biological fixation between the stem and the femur. The area of contact between the femur and the stem was divided into seven zones based on Gruen’s zone classification. Results All 73 patients had no SW 6 weeks after surgery on radiography and digital tomosynthesis. Three months postoperatively, there was no SW on radiography; however, digital tomosynthesis revealed SW in 31 (42%) patients. Six months postoperatively, radiography showed 22 SW in 18 (24.7%) patients and digital tomosynthesis showed 94 SW in 48 patients (65.8%). Conclusion Digital tomosynthesis detected biological fixation between the stem and femur earlier than radiography; biological fixation may appear within 3 months after surgery.

Background and aims Digital tomosynthesis has proven useful in the evaluation of damage to joints. This study aims to describe the most common digital tomosynthesis findings for four rheumatological entities and to compare the usefulness of this technique with that of other imaging techniques. Materials and methods Following the PRISMA guidelines, we systematically searched the literature for articles about the use of digital tomosynthesis in rheumatoid arthritis, osteoarthritis, spondyloarthritis, and gout. We used the QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies) criteria to evaluate the quality of the articles included. Results We included 13 articles. For rheumatoid arthritis, osteoarthritis, and spondyloarthritis, digital tomosynthesis detected bone abnormalities better than plain-film X-rays; however, for gout, the results were variable. Conclusions Digital tomosynthesis can play an important role in the evaluation of skeletal abnormalities in rheumatological disease, especially compared to plain-film X-rays.

To determine the best screening modality for breast cancer, a large randomized clinical trial is underway to compare the mammographic accuracy between the standard digital and tomosynthesis mammography. The Tomosynthesis Mammographic Imaging Screening Trial (TMIST) is also building the world's largest biorepository of breast cancer specimens from all biopsies at screening and wants to ensure it is representative of the US population. We invite the National Medical Association physicians, as leaders in the health care of African Americans, to continue their commitment to eliminating disparities by promoting the TMIST among African American women. The outcome of the trial will help to advance precision screening, individually tailoring screening decisions based on breast density, tumor subtyping and genomics. The partnership with NMA is essential to building trust, dispelling misconceptions about clinical trials in the community as well as to support a cadre of African American physicians and researchers who can contribute to the current understanding of the social determinants of breast cancer.

To evaluate a tomosynthesis screening mammography automated outcomes feedback application's adoption and impact on performance.This prospective intervention study evaluated a feedback application that provided mammographers subsequent imaging and pathology results for patients that radiologists had personally recalled from screening. Deployed to 13 academic and 5 private practice attending radiologists, adoption was studied from March 29, 2018, to March 20, 2019. Radiologists indicated if reviewed feedback would influence future clinical decisions. For a subset of eight academic radiologists consistently interpreting screening mammograms during the study, performance metrics were compared pre-intervention (January 1, 2016, to September 30, 2017) and post-intervention (October 1, 2017 to June 30, 2018). Abnormal interpretation rate, positive predictive value of biopsies performed, sensitivity, specificity, and cancer detection rate were compared using Pearson's χThe 18 radiologists reviewed 68.5% (1,398 of 2,042) of available feedback cases and indicated that 17.4% of cases (243 of 1,398) could influence future decisions. For the eight academic radiologist subset, after multivariable adjustment with comparison to pre-intervention, average abnormal interpretation rate decreased (from 7.5% to 6.7%, adjusted odds ratio [aOR] 0.86, P.01), positive predictive value of biopsies performed increased (from 40.6% to 51.3%, aOR 1.48, P = .011), and specificity increased (from 93.0% to 93.9%, aOR 1.17, P.01) post-intervention. There was no difference in cancer detection rate per 1,000 examinations (from 5.8 to 6.1, aOR 1.01, P = .91) or sensitivity (from 81.2% to 78.7%, aOR 0.84, P = .47).Radiologists used a screening mammography automated outcomes feedback application. Its use decreased false-positive examinations, without evidence of reduced cancer detection.

This study assessed effective doses (E) from conventional and stationary intraoral tomosynthesis (s-IOT) radiography for posterior bitewing (PBW) examinations and evaluated the effect of sensor attenuation.An adult human tissue-equivalent phantom and optically stimulated luminescent dosimeters were used. Series of 4 PBW radiographs were acquired with circular and rectangular collimation. s-IOT PBW radiographs were acquired with built-in rectangular collimation. Radiographs were acquired without and with a sensor in the beam path.E (in µSv) was 15.7 and 8.2 for conventional-circular, 4.6 and 1.1 for conventional-rectangular, and 11.9 and 5.9 for s-IOT in sensor-absent and sensor-present scenarios, respectively. For sensor-absent exposures, E for conventional-rectangular was 29.3% and E for s-IOT was 75.8% of the conventional-circular dose. With the sensor present, these values were 13.4% and 72.0%, respectively (P.001). Sensor-present E was lower than sensor-absent E for all modalities (P.001). Reductions in equivalent doses were similar to effective dose reductions.For PBW examinations, E for s-IOT was smaller than for conventional radiography with circular collimation, but larger than for conventional radiography with rectangular collimation. The presence of a sensor maintained these differences but reduced E for all modalities.

To evaluate conspicuity of screen-detected cancers on two-dimensional synthetic mammography (SM) reconstructed from digital breast tomosynthesis (DBT) compared to two-dimensional full field digital mammography (FFDM).IRB-approved retrospective review of consecutive screen-detected cancers from October 1, 2015 to June 30, 2017 was performed. All examinations were reviewed by three radiologists in consensus (n = 224); a score of 1-3 was given to each screen-detected cancer on SM vs. FFDM [1 = FFDM more conspicuous than SM, 2 = FFDM equivalent to SM, and 3 = SM more conspicuous than FFDM]. Findings considered only visible on tomosynthesis (n = 40), without medical history (n = 2), and with skin thickening only (n = 1) were excluded, leaving 181 cases as the study population. The longitudinal medical record was reviewed to determine patient demographics and outcomes of imaging surveillance and biopsy.Mammographic features on SM (n = 181) were calcifications (n = 68, 37.8%), masses (n = 51, 27.8%), asymmetries (n = 50, 27.6% [11 focal asymmetries]), and distortion (n = 12, 6.8%). The majority (76%, 137/181) of findings were equal or more conspicuous on SM vs. FFDM. However, calcifications and distortion greater than 2 cm were more conspicuous on SM and asymmetries were less conspicuous on SM vs. FFDM, controlling for menopausal status, family or personal history of breast cancer, BRCA status, and breast density.Although the majority of screen-detected cancers are equal to more conspicuous on SM when compared to FFDM, calcifications and asymmetries2cm were less conspicuous on SM than FFDM. When SM + DBT is used as an alternative to FFDM + DBT in breast cancer screening, caution should be taken when assessing one-view asymmetries and findings2cm on SM.

Purpose To compare tomosynthesis and computed tomography (CT) for evaluating bone plug integration after anterior cruciate ligament (ACL) reconstruction with a bone–patellar tendon–bone (BPTB) graft. Methods Data of consecutive adult patients who underwent ACL reconstruction with BPTB were analyzed. Bone integration between the bone plug and bone tunnel was evaluated by tomosynthesis and CT, which were both performed 3 months postoperatively. The obtained data for both modalities were reconstructed with slice thickness of 2 mm. Evaluation of bone integration were separately performed using coronal- and sagittal-reconstructed images for the femur and tibia. The ratio of bone integration between the reconstructed slices in which bone grafting was involved, for both tomosynthesis and CT, was investigated by 2 blinded examiners. The equivalence of tomosynthesis to CT was tested by comparing the bone integration ratio for both modalities. The accuracy of diagnosing bone union using tomosynthesis and CT was also investigated. Results The diagnostic accuracy of tomosynthesis and CT exceeded 80%. Interobserver agreement of bone integration in the sagittal plane on the femoral side was 0.92 (intraclass correlation coefficient) for CT and 0.76 (intraclass correlation coefficient) for tomosynthesis. Conclusions Although it showed poor reliability, tomosynthesis was equivalent to CT in evaluating bone plug integration after ACL reconstruction with BPTB. Level of Evidence Level II, diagnostic study.

Rationale and Objectives We investigated if imaging or pathology features could determine when imaging follow-up is appropriate after diagnosis of radial scar on digital breast tomosynthesis (DBT)-guided core needle biopsy (CNB). Materials and Methods We conducted a retrospective review of all patients diagnosed with radial scars on DBT-guided CNB at our institution between November 2014 and December 2016. Cases were excluded if DCIS or invasive malignancy was present in the same core specimens. Patient age; needle size; number of cores; visibility on full-field digital mammography versus DBT; lesion size; presence of architectural distortion, mass, or calcifications; imaging stability; presence or absence of atypia; length of imaging follow-up, and excisional pathology were collected. Results Of 45 eligible biopsies, 6 cases had radial scars with associated atypia and 39 cases had no associated atypia. Twenty-four patients underwent surgical excision, including all patients with atypia on CNB. One case (4%) was upstaged to DCIS on surgical excision after CNB revealed a radial scar with associated ADH. There was also a case without atypia on CNB, but excisional pathology revealed associated ADH. In cases with radial scars and associated atypia on CNB, the upstage rate was 17%. In cases without atypia on CNB that underwent surgical excision, the upstage rate was 0%. Imaging follow-up was available in 13 patients who did not undergo surgical excision, with stability in all 13 with a median follow-up of 18 months. Conclusion Annual imaging follow-up appears reasonable in selected patients with radial scars but no atypia on DBT-guided CNB.

Objectives The purpose of this study is to retrospectively evaluate the presence of screening digital breast tomosynthesis (DBT) correlates for suspicious lesions detected on pre-operative staging magnetic resonance imaging (MRI) in patients with newly diagnosed breast cancer. Methods After approval from the institutional review board (IRB), screening DBTs on breast cancer patients with BI-RADS 4 or 5 staging MRI exams between 8/1/17 and 8/1/18 were assessed for presence of DBT correlates for suspicious MRI findings. The pathology of the index lesion, type of additional MRI finding (mass, non-mass enhancement, or focus), correlative finding on tomosynthesis (mass, asymmetry/focal asymmetry, distortion, or calcifications), size on MRI and tomosynthesis, breast density, and pathology of the additional lesion were recorded. The chi-square test of association was used unless otherwise specified. Confidence intervals for proportions were estimated using the Wilson's score method. Results 17/70 (24%) of additional lesions seen on pre-operative MRI exams in patients with newly diagnosed cancer had a mammographic correlate on corresponding screening DBT. There was no significant relationship between the presence of a mammographic correlate and the type of MRI finding (mass, NME, or focus), breast density, size of lesion, pathology of index cancer, or pathology of the additional lesion (p≥ 0.05). Conclusions 76% of additional lesions seen on pre-operative staging MRI in patients with newly diagnosed breast cancer are not seen retrospectively on screening DBT. Since about 24% of MRI-detected additional lesions may have a DBT correlate, DBT exams should be reviewed in patients recalled for further workup of findings seen on pre-operative MRI since this may facilitate DBT-guided biopsy of suspicious lesions, which is preferable to MRI-guided biopsy for cost and patient comfort reasons.

Purpose We present the development and the current state of the MaXIMA Breast Lesions Models Database, which is intended to provide researchers with both segmented and mathematical computer-based breast lesion models with realistic shape. Methods The database contains various 3D images of breast lesions of irregular shapes, collected from routine patient examinations or dedicated scientific experiments. It also contains images of simulated tumour models. In order to extract the 3D shapes of the breast cancers from patient images, an in-house segmentation algorithm was developed for the analysis of 50 tomosynthesis sets from patients diagnosed with malignant and benign lesions. In addition, computed tomography (CT) scans of three breast mastectomy cases were added, as well as five whole-body CT scans. The segmentation algorithm includes a series of image processing operations and region-growing techniques with minimal interaction from the user, with the purpose of finding and segmenting the areas of the lesion. Mathematically modelled computational breast lesions, also stored in the database, are based on the 3D random walk approach. Results The MaXIMA Imaging Database currently contains 50 breast cancer models obtained by segmentation of 3D patient breast tomosynthesis images; 8 models obtained by segmentation of whole body and breast cadavers CT images; and 80 models based on a mathematical algorithm. Each record in the database is supported with relevant information. Two applications of the database are highlighted: inserting the lesions into computationally generated breast phantoms and an approach in generating mammography images with variously shaped breast lesion models from the database for evaluation purposes. Both cases demonstrate the implementation of multiple scenarios and of an unlimited number of cases, which can be used for further software modelling and investigation of breast imaging techniques. The created database interface is web-based, user friendly and is intended to be made freely accessible through internet after the completion of the MaXIMA project. Conclusions The developed database will serve as an imaging data source for researchers, working on breast diagnostic imaging and on improving early breast cancer detection techniques, using existing or newly developed imaging modalities.

Non-conventional scan trajectories for interventional three-dimensional imaging promise low-dose interventions and a better radiation protection to the personnel. Circular tomosynthesis (cTS) scan trajectories yield an anisotropical image quality distribution. In contrast to conventional Computed Tomographies (CT), the reconstructions have a preferred focus plane. In the other two perpendicular planes, limited angle artifacts are introduced. A reduction of these artifacts leads to enhanced image quality while maintaining the low dose. We apply Deep Artifact Correction (DAC) to this task. cTS simulations of a digital phantom are used to generate training data. Three U-Net-based networks and a 3D-ResNet are trained to estimate the correction map between the cTS and the phantom. We show that limited angle artifacts can be mitigated using simulation-based DAC. The U-Net-corrected cTS achieved a Root Mean Squared Error (RMSE) of 124.24 Hounsfield Units (HU) on 60 simulated test scans in comparison to the digital phantoms. This equals an error reduction of 59.35% from the cTS. The achieved image quality is similar to a simulated cone beam CT (CBCT). Our network was also able to mitigate artifacts in scans of objects which strongly differ from the training data. Application to real cTS test scans showed an error reduction of 45.18% and 26.4% with the 3D-ResNet in reference to a high-dose CBCT.

The symptoms of lumbar foraminal stenosis are often exacerbated when the patient is upright. Lumbar pathological conditions related to clinical symptoms such as disc herniation, foraminal stenosis, and instability of the lumbar spine are often exacerbated when the patient is upright and hidden when the patient is supine. Lumbar radiculopathy is usually diagnosed by MRI. However, it is difficult to detect the compression of nerve roots while the patient is upright using conventional MRI when the patient is supine. Dynamic digital tomosynthesis radiculography (DTRG) while the patient is upright detects pathological changes of the lumbar nerve root while the patient is upright. We report cases of symptomatic lumbar foraminal stenosis which were diagnosed by using digital tomosynthesis radiculography with the patient in an upright position. Three patients with history of unilateral leg pain which was exacerbated when they were upright underwent selective nerve root block and DTRG in both prone and upright positions. All patients were relieved of the leg pain after selective nerve root block. DTRG with the patient in an upright position showed better exacerbation of nerve root compression than while the patient was prone in all cases. DTRG with the patient in prone and upright positions is useful to detect compression of nerve roots hidden while MRI is conducted with the patient supine. DTRG is helpful to diagnose lumbar foraminal stenosis which is exacerbated while the patient is upright.

The use of preoperative breast MRI remains controversial despite being the most sensitive technique for the detection of breast malignancies.To evaluate the benefit of preoperative breast MRI after performing the three conventional techniques (DM, US, DBT). To analyze the influence of breast density in the sensitivity of the different imaging techniques.Retrospective review of 280 histologically confirmed breast cancers in 192 women. We reviewed the medical records and evaluated the change of treatment induced by MRI. Also, we assessed the reports of DM and the combination of the different imaging techniques, and categorized them according to ACR density (a-d) and as negative (BI-RADS 1-3) or positive (BIRADS 4 or 5). The gold standard was the pathologic assessment of the surgical specimen. The sensitivity of the different techniques was compared using McNemar test.Among these 192 women the use of MRI did not significantly increase the mastectomy rate (from 16.6% to 17.6%; p = 0.5). The addition of any technique demonstrated a higher sensitivity than DM alone. The sensitivity of DM alone was 52.5% while using all the techniques, including MRI, was 94.3% (p 0.001). Regardless of breast density pattern, the addition of any technique significantly increased the sensitivity of DM (p 0.001).The addition of MRI to the three conventional techniques increased the sensitivity but did not significantly modify the rate of mastectomies. Additional techniques increased the sensitivity of DM in both dense and non-dense breasts.

Imaging plays a critical role in the diagnosis and management of breast cancer. Two-view mammography and ultrasound form the mainstay of breast imaging and are essential components of the triple assessment. Digital mammography is rapidly replacing analogue mammography, and recent advances such as digital tomosynthesis add a third dimension to conventional 2D mammographic images. The versatility of ultrasound allows assessment of the breast and axilla as well as accurately targeted interventions, from the simple diagnostic core biopsy to preoperative tumour localization. It also guides large volume biopsies and excision of certain benign lesions, which in some cases can obviate surgical excision. Newer ultrasound techniques being applied to the breast and axilla include elastography and the use of intradermal microbubbles to guide the radiologist to the sentinel axillary node. Breast MRI is a powerful modality in assessing breast cancer. It can provide accurate information on size and multifocality of lesions, particularly those that are mammographically challenging such as lobular cancers, and it is also used to assess response to neoadjuvant chemotherapy and guide surgical management. CT scans, and in selected cases Positron Emission Tomography, play important roles in the assessment of metastatic disease.

Computer Aided Diagnosis (CAD) systems can support physicians in classifying different kinds of breast cancer, liver cancer and blood tumours also revealed by images acquired via Computer Tomography, Magnetic Resonance, and Blood Smear systems. In this regard, this survey focuses on papers dealing with the description of existing CAD frameworks for the classification of the three mentioned diseases, by detailing existing CAD workflows based on the same steps for supporting the diagnosis of these tumours. In detail, after an appropriate acquisition of the images, the fundamental steps carried out by a CAD framework can be identified as image segmentation, feature extraction and classification. In particular, in this work, specific CAD frameworks are considered, where the task of feature extraction is performed by using both traditional handcrafted strategies and Convolutional Neural Networks-based innovative methodologies, whereas the final supervised pattern classification is based on neural/non-neural machine learning methods. The cited methodology is focused on sharing and reviewing an amount of specific works. Then, the performance of three selected case studies are carefully reported, designed with the aim of showing how final outcomes can vary according to different choices in each step of the adopted workflow. More in detail, these case studies concern with breast images acquired by Tomosynthesis and Magnetic Resonance, hepatocellular carcinoma images acquired by Computed Tomography and enhanced by a triphasic protocol with a contrast medium, peripheral blood smear images for cellular blood tumours and are used to compare their performance.

Digital breast tomosynthesis is an advancement of the mammographic technique, with the potential to increase detection of lesions during breast cancer screening. The main aim of the Malmö Breast Tomosynthesis Screening Trial (MBTST) was to investigate the accuracy of one-view digital breast tomosynthesis in population screening compared with standard two-view digital mammography.In this prospective, population-based screening study, of women aged 40-74 years invited to attend national breast cancer screening at Skåne University Hospital, Malmö, Sweden, a random sample was asked to participate in the trial (every third woman who was invited to attend regular screening was invited to participate). Participants had to be able to speak English or Swedish and were excluded from the study if they were pregnant. Participants underwent screening with two-view digital mammography (ie, craniocaudal and mediolateral oblique views) followed by one-view digital breast tomosynthesis with reduced compression in the mediolateral oblique view (with a wide tomosynthesis angle of 50°) at one screening visit. Images were read with masked double reading and scoring by two separate reading groups, one for each method, made up of seven radiologists. Any cancer detected with a malignancy probability score of three or higher by any reader in either group was discussed in a consensus meeting of at least two readers, from which the decision of whether or not to recall the woman for further investigation was made. The primary outcome measures were sensitivity and specificity of breast cancer detection. Secondary outcome measures were screening performance measures of cancer detection, recall, and interval cancers (cancers clinically detected between screenings), and positive predictive value for screen recalls and negative predictive value of each method. Outcomes were analysed in the per-protocol population. Follow-up of the participants for at least 2 years allowed for identification of interval cancers. This trial is registered with ClinicalTrials.gov, number NCT01091545.Between Jan 27, 2010, and Feb 13, 2015, of 21 691 women invited, 14 851 (68%) agreed to participate. Three women withdrew consent during follow-up and were excluded from the analyses. 139 breast cancers were detected in 137 (1%) of 14 848 women. Sensitivity was higher for digital breast tomosynthesis than for digital mammography (81·1%, 95% CI 74·2-86·9, vs 60·4%, 52·3-68·0) and specificity was slightly lower for digital breast tomosynthesis than was for digital mammography (97·2%, 95% CI 97·0-97·5, vs 98·1%, 97·9-98·3). The proportion of cancers detected was significantly higher with digital breast tomosynthesis than with digital mammography (8·7 cancers per 1000 women screened, 95% CI 7·3-10·3 vs 6·5 cancers per 1000 screened, 5·2-7·9; p0·0001). The proportion of women recalled after discussion was higher among cancers detected by digital breast tomosynthesis than for those detected by digital mammography after consensus (3·6%, 95% CI 3·3-3·9 vs 2·5%, 2·2-2·8; p0·0001). The positive predictive value for screen recalls was 24·1% (95% CI 20·5-28·0) for digital breast tomosynthesis and 25·9% (21·6-30·7) for digital mammography, and the negative predictive value was 99·8% (99·7-99·9) and 99·6% (99·4-99·7), respectively. The proportion of women who developed interval cancers after trial screening was 1·48 cancers per 1000 women screened (95% CI 0·93-2·24).Breast cancer screening by use of one-view digital breast tomosynthesis with a reduced compression force has higher sensitivity at a slightly lower specificity for breast cancer detection compared with two-view digital mammography and has the potential to reduce the radiation dose and screen-reading burden required by two-view digital breast tomosynthesis with two-view digital mammography.The Swedish Cancer Society, The Swedish Research Council, The Breast Cancer Foundation, The Swedish Medical Society, The Crafoord Foundation, The Gunnar Nilsson Cancer Foundation, The Skåne University Hospital Foundation, Governmental funding for clinical research, The South Swedish Health Care Region, The Malmö Hospital Cancer Foundation and The Cancer Foundation at the Department of Oncology, Skåne University Hospital.

Recently, digital tomosynthesis systems have been actively investigated to reduce radiation dose in medical imaging. In this work, we present various beam modulation schemes for low-dose digital tomosynthesis; we compared the effects of the various acquisition schemes on image quality. A prototype chest digital tomosynthesis (CDT) system (LISTEM, Korea) and the LUNGMAN phantom (Kyoto Kagaku, Japan) with lung nodules were used in this study. A total of 81 projection data obtained through various beam modulation schemes over a 40° angular range were reconstructed using the filtered back projection (FBP) algorithm. The contrast noise ratio (CNR), structural similarity index (SSIM), and peak signal-to-noise ratio (PSNR) of the lung nodules were calculated to evaluate the image quality depending on the acquisition scheme. The reconstructed images obtained based on the proposed beam modulation schemes showed enhanced contrast in addition to a reduction of the area dose. It was determined that the beam modulation schemes affect the image quality. Among beam modulation schemes we investigated, the bunched view acquisition (outer focused) showed promising results within the region of interest (ROI). The reconstructed image obtained using the bunched view showed an increase of the CNR value by 63% compared to the conventional acquisition method. In addition, shutter scan acquisition showed promising results for the restoration information for the outside ROI. We determined that the beam modulation schemes in the prototype CDT system affect the image quality. It is also expected that the patient exposure dose can be reduced by modulating the beam size in the prototype CDT system.

The purpose of this study was to examine the potential of digital tomosynthesis (DTS) derived cancellous bone textural measures to predict vertebral strength under conditions simulating a wedge fracture. 40 vertebral bodies (T6, T8, T11, and L3 levels) from 5 male and 5 female cadaveric donors were utilized. The specimens were scanned using dual energy X-ray absorptiometry (DXA) and high resolution computed tomography (HRCT) to obtain measures of bone mineral density (BMD) and content (BMC), and DTS to obtain measures of bone texture. Using a custom loading apparatus designed to deliver a nonuniform displacement resulting in a wedge deformity similar to those observed clinically, the specimens were loaded to fracture and their fracture strength was recorded. Mixed model regressions were used to determine the associations between wedge strength and DTS derived textural variables, alone and in the presence of BMD or BMC information. DTS derived fractal, lacunarity and mean intercept length variables correlated with wedge strength, and individually explained up to 53% variability. DTS derived textural variables, notably fractal dimension and lacunarity, contributed to multiple regression models of wedge strength independently from BMC and BMD. The model from a scan orientation transverse to the spine axis and in the anterior-posterior view resulted in highest explanatory capability (R 2 adj = 0.91), with a scan orientation parallel to the spine axis and in the lateral view offering an alternative (R 2 adj = 0.88). In conclusion, DTS can be used to examine cancellous texture relevant to vertebral wedge strength, and potentially complement BMD in assessment of vertebral fracture risk.

Recently, cone-beam computed tomography (CBCT) equipped with image-guided radiation therapy (IGRT) has been used to precisely identify the location of target lesion. However, the treatment accuracy for respiratory-sensitive regions is still low due to long scanning time and target motion, and the imaging dose is also relatively high compared to other imaging systems. These issues can be solved by using 4D IGRT with digital tomosynthesis (DT). Also, an application of graphics processing unit (GPU) computing can reduce reconstruction time. The purpose of this study was to develop a 4D DT imaging technique for IGRT and compare image quality between 3D DT and 4D DT. And, we also compared reconstruction time between CPU and GPU computing. Projections were separately obtained through 3 phases for simulating 4D DT imaging. We measured profile, normalized root-mean-square error (NRMSE), contrast-to-noise ratio (CNR), noise-power spectrum (NPS) and figure-of-merit (FOM). NRMSEs and CNRs of 4D DT images were averagely 0.56 and 0.74 times lower than those of 3D DT images, respectively. The NPSs of 4D DT images were higher than 3D DT images. The FOMs of 4D DT images were averagely 1.65 times higher than 3D DT images. The GPU computing reduced reconstruction time in 3D and 4D imaging by a factor of 0.11 and 0.56, respectively. As a results, the 4D DT imaging enables the high-precision IGRT for respiratory-sensitive regions, and the real-time 4D imaging would be possible by using the GPU computing.

Digital breast tomosynthesis (DBT) when combined with standard 2D digital mammography has been shown to improve the performance of breast cancer screening by increasing cancer detection rates [1-5]. The 2D component remains an important part of the examination and is used to facilitate assessment of symmetry between the breasts, aid comparison with prior mammograms and identify the presence of breast microcalcifications where the evidence for detection with DBT is less robust [1]. The mean glandular dose per view of a DBT image is around 2.3 mGy, which is between 1 - 1.5x more than the dose of standard 2D digital mammography [6]. Acquiring both a DBT and standard 2D digital mammogram on each woman leads to at least a doubling of the radiation dose, which may not be considered acceptable in an asymptomatic screening population. Consequently there has been much interest in the generation of synthetic 2D mammograms from the DBT data set eliminating the additional radiation burden of a separate 2D digital mammogram. There is evidence from prospective and retrospective studies to support the use of synthetic 2D mammograms [5,7-9]. Several retrospective multi-reader studies, including the UK TOMMY trial, have demonstrated comparable performance between synthetic and conventional 2D mammography [7,8]. The Oslo and Storm-2 prospective studies of DBT in breast cancer screening found equivalent cancer detection rates regardless of whether the conventional 2D or the synthetic mammograms were read, concluding that synthetic mammograms were an acceptable replacement for directly acquired conventional 2D mammograms [5,9]. Another approach to improve performance is to combine the synthesised image with a Computer Aided Detection (CAD) algorithm. CAD has been used over the years to assist with the interpretation of 2D mammography. CAD software places marks or prompts on the images to draw the reader’s attention to potential areas of concern, reducing observational oversights. A CAD algorithm has been developed with machine learning technology (iCAD Inc., Nashua , NH, USA and GE Healthcare, Buc, France) to assist in the detection of breast cancer on DBT images. Unlike a conventional CAD system which places marks on the image, areas of concern are automatically identified on each tomosynthesis slice and then blended onto a 2D synthetic image to provide a single CAD enhanced 2D synthetic image for each mammographic projection. The aim of this study was to evaluate the diagnostic performance of the CAD enhanced synthetic mammogram in comparison with standard 2D synthetic mammograms generated from the DBT data set and standard 2D digital mammography.

Purpose To investigate whether combined Digital breast tomosynthesis and Automated breast volume scanner (DBT-ABVS) are comparable to Magnetic resonance imaging (MRI) in staging breast cancer. Methods We retrospectively included seventy-three patients with histologically proven breast cancer who underwent preoperative DBT, ABVS and 1.5 T MRI in the period July 2015–July 2016. Two radiologists in consensus recorded the number, site and Breast imaging-reporting and data system (BI-RADS) category of breast findings during two independent reading strategies, i.e. DBT-ABVS vs. MRI. Using histology or 1-year follow up as the standard of reference, we calculated the accuracy for cancer of both imaging strategies. Bland-Altman analysis was used to evaluate the agreement between MRI vs. DBT or ABVS in cancer size assessment. Results Patients showed a total of 160 lesions (108 malignant and 52 benign). Malignant lesions were unifocal, multifocal, multicentric and biltateral in 53, 15, 4 and 1 cases, respectively. Diagnostic accuracy of DBT-ABVS vs. MRI was comparable for all cancers (90.0% [95%C.I. 84.3–94.2] vs. 93.8% [95%C.I. 88.8–97.0], respectively). DBT-ABVS showed lower sensitivity and positive predictive values for additional disease (76.5% [95%C.I. 58.8–89.3] vs. 91.7% [95%C.I. 84.6–96.1], and 78.8% [95%C.I. 61.0–91.0] vs 93.4% [95%C.I. 86.9–97.3], respectively). Compared to MRI, ABVS + DBT missed 6 lesions, including two invasive cancers and one extensive intravascular invasion associated to ductal carcinoma in situ. Bland-Altman analysis showed ABVS to agree with MRI at a higher extent than DBT in assessing cancer size. Conclusions Though less performing than MRI, DBT-ABVS showed acceptable diagnostic accuracy in staging breast cancer. This strategy might be used if MRI is unavailable or unfeasible.

Understanding the properties of slice sensitivity profile (SSP), or slice thickness, is crucial for an accurate and highly reproducible diagnosis using tomosynthesis imaging. The objectives of the present study are therefore to quantitatively evaluate how the SSP with the use of a small metal bead is affected by different settings of the height from the table and the height of the center of rotation (COR) in tomosynthesis imaging except for the digital breast tomosynthesis, and visually verify the effects on tomosynthesis images. The reconstruction filters used were three types of filtered back-projection and iterative reconstructions. The SSP was measured from the full width at half maximum (FWHM-SSP) of the profile curve of the bead in the perpendicular direction (z direction) relative to the table. Two types of anthropomorphic phantoms simulating the human body, with bones and soft tissues, were used to study the effects of different settings for the COR height. In all reconstruction filters, the FWHM-SSP changed as the height of the bead varied when the bead and COR were set to the same height from the table. If the bead and the COR were set to different heights, the FWHM-SSP increased (decreased) when the height of the bead was set to be greater (less) than the height of the COR. These changes were also confirmed on the anthropomorphic phantom images of the bones and soft tissues.

Background We previously reported the Screening with tomosynthesis or standard mammography-2 (STORM-2) trial, showing that tomosynthesis (3D-mammography) screening detected more cancers than 2D-mammography in double-reading practice. In this study, we report reader-specific detection measures for radiologists who performed the screen-reading in this trial. Methods This is a sub-study of the STORM-2 trial which prospectively integrated 3D-mammography with acquired or synthetized 2D-mammograms in parallel double-reading arms. Asymptomatic women ≥49 years who attended population-based screening (Trento, 2013–2015) were recruited. Screening participants were recalled at any positive sequential screen-read in either reading arm of the trial. Radiologist-specific detection measures were calculated for each of seven radiologists who performed screen-reads: number of detected cancers, proportion of true-positive (TP) detection, and number and rate of false-positive (FP) recalls (FPR). We estimated incremental cancer detection rate (CDR) from integrating 3D-mammography in screen-reading. Results Across all radiologists, TP detection (relative sensitivity) ranged between: 46% and 100% (median 59.5%) for 2D-mammography; 75% and 100% (median 76%) for integrated 2D/3D-mammography screening; 56% and 76% (median 64%) for 2Dsynthetic; 67% and 88% (median 78%) for 2Dsynthetic/3D-mammography. Integrating 3D-mammography led to incremental CDRs between 0/1000 and 3.5/1000 screens. FPR ranged between: 1.2% and 2.7% (median 2.25%) for 2D-mammography; 1.5% and 3.4% (median 2.75%) for 2D/3D-mammography; 1.6% and 4.6% (median 2.4%) for 2Dsynthetic; and 1.8% and 6.7% (median 3.0%) for 2Dsynthetic/3D-mammography. Conclusions There was variability in the magnitude of effect from integrating 3D-mammography (relative to screen-reading with acquired or synthesised 2D-mammography alone) on individual radiologist’s TP and FP detection, although there was an overall pattern of increasing cancer detection and also increasing FP recall for most readers.

Aim To compare reader recall rate and confidence associated with recall decisions for digital mammography (DM) alone with DM plus digital breast tomosynthesis (DBT) in the prevalent screening round. Materials and methods Following regional ethics committee approval and written informed consent from all participating women, DM and DBT were obtained. DM followed by the combination of DM plus DBT were reviewed retrospectively by one of nine radiologists, for 880 women aged between 46 and 53. Differences in recall rates and reader confidence were assessed using the McNemar test and sign test, respectively. Subgroup analyses were performed for conventional prevalent round (aged 50–53 years) and age extension trial (aged 46–49 years) groups, as well as low breast density (BI-RADS A and B) and high breast density (BI-RADS C and D) groups. Results The recall rate using DM alone was 17.4% (95% confidence interval [CI] 15, 20). The recall rate using DM and DBT was 11.4% (95% CI: 9.5 to 13.8). There was a relative reduction of 35% (p=0.0001). There were reductions in both the conventional prevalent round (31.1% reduction, p=0.004) and age extension subgroups (37% reduction, p=0.0007). There were also reductions in both the low density group (37.2% reduction, p=0.0007) and the high density group (31.1% reduction, p=0.003). The median confidence rating with the recall decision was 7/10 using DM and 8/10 using the combination of DM and DBT (p=0.0001). Conclusion The addition of DBT to DM in the prevalent screening round was found to reduce the reader recall rate, with a modest associated increase in reader confidence.

To assess the diagnostic performance of digital tomosynthesis (DT) in detecting urolithiasis and compare it with ultrasonography (USG), keeping standard volumetric multi-detector computed tomography (MDCT) as the reference.This prospective analytical study was approved by our institutional ethical committee. A total of 66 patients were enrolled who had either clinical suspicion of urolithiasis or history of recurrent urolithiasis. All patients underwent DT, USG and MDCT within 24 h. In all these three investigations, the calculi were categorised according to their location and size by two radiologists. Sensitivity, specificity, positive and negative predictive values of DT and USG were calculated with MDCT as a reference standard.Our study comprised of 66 patients (36 males and 30 females with age range of 19-73 years). A total of 121 calculi were assessed with 52 calculi5 mm in size, 32 calculi measuring 5-10 mm and 37 calculi10 mm. Kappa test of agreement was used to assess the interobserver agreement for all observations. The measurement of agreement kappa value was 1. The overall sensitivity of DT and USG in detecting urolithaisis was 50% (p value0.001) and 50.4% (p value 0.005) respectively. No statistically significant difference was noted between USG and DT in detecting urolithiasis. The sensitivity of DT and USG in detecting renal calculi was 47.1% and 50.9% respectively and the sensitivity of DT and USG in detecting ureteric calculi was 74.9% and 39.2% respectively. We observed statistically significant difference between USG and DT in detecting ureteric calculi.In our study, there was no statistically significant difference noted between USG and DT in diagnosis of urolithiasis. DT performed significantly better than USG in detecting ureteric calculi with a higher sensitivity. Hence, we are tempted to opine that DT may be preferred over USG for initial evaluation of patients with suspected ureteric calculi. However considering the strength of ultrasound in demonstrating associated signs as hydroureteronephosis, we are still of the opinion, that both DT and USG should be used as complementary techniques in resolving these common clinical screnarios.

Tomosynthesis is an imaging technique that uses standard X-ray equipment with digital flat panel detectors to create tomographic images from very low-dose projections obtained at different angles. These images are parallel to the plane of the detector. Filtered back-projection or iterative reconstruction algorithms can be used to produce them. Iterative reconstruction used with a metal artifact reduction algorithm reduces metal artifacts, and therefore, improve image quality and in-depth spatial resolution. The radiation dose is lower compared to that of computed tomography and is two to three times the dose of a standard radiography. Tomosynthesis is intended for the analysis of high-contrast structures and especially for bones. It is superior to projection radiography when bone superimpositions are important or when metal structures hide regions of interest. The high in-plane resolution and its ability to perform exams in weight-bearing positioning are some of the main advantages of this technique. The impossible production of perpendicular multiplanar reconstruction and a limited contrast resolution are its main limitations. Tomosynthesis must be considered as an extension or an addition to standard radiography, as it can be performed in the same diagnostic step. The purpose of this article was to describe the principles, advantages and limitations, and current and future applications in musculoskeletal pathology of tomosynthesis.

The present study aimed to introduce a recently developed digital tomosynthesis system for the chest and describe the procedure for acquiring dual energy bone decomposed tomosynthesis images. Various beam quality and reconstruction algorithms were evaluated for acquiring dual energy chest digital tomosynthesis (CDT) images and the effective dose was calculated with ion chamber and Monte Carlo simulations. The results demonstrated that dual energy CDT improved visualization of the lung field by eliminating the bony structures. In addition, qualitative and quantitative image quality of dual energy CDT using iterative reconstruction was better than that with filtered backprojection (FBP) algorithm. The contrast-to-noise ratio and figure of merit values of dual energy CDT acquired with iterative reconstruction were three times better than those acquired with FBP reconstruction. The difference in the image quality according to the acquisition conditions was not noticeable, but the effective dose was significantly affected by the acquisition condition. The high energy acquisition condition using 130 kVp recorded a relatively high effective dose. We conclude that dual energy CDT has the potential to compensate for major problems in CDT due to decomposed bony structures, which induce significant artifacts. Although there are many variables in the clinical practice, our results regarding reconstruction algorithms and acquisition conditions may be used as the basis for clinical use of dual energy CDT imaging.

Screening mammography saves lives. The mainstay of screening has been mammography. Multiple alternative options, however, for supplemental imaging are now available. Some are just improved anatomic delineation whereas others include physiology added to anatomy. A third group (molecular imaging) is purely physiologic. This article describes and compares the available options and for which patient populations they should be used.

Contrast-enhanced mammography (CEM) is a contrast-enhanced modality for breast cancer detection that utilizes iodinated contrast and dual-energy imaging performed on a digital mammography unit with only slight modifications. It is approved by the US Food and Drug Administration, commercially available, and in routine clinical use at centers around the world. It has similar sensitivity and specificity to MR Imaging and has advantages in terms of cost, patient acceptability, and examination time. MR Imaging has some advantages compared with CEM, especially in its ability to image the complete axilla and the chest wall.

Breast MR imaging has been shown to identify unsuspected sites of cancer in the ipsilateral breast in 16% of women with newly diagnosed breast cancer. Breast MR imaging identifies occult cancer in the contralateral breast in 3% to 5% of women. Early evidence suggests that the added value of MR imaging for staging may be attenuated in women who also undergo tomosynthesis, particularly those with nondense breasts. Breast MR imaging is complementary to ultrasound imaging in evaluating regional nodal basins. Ongoing prospective randomized clinical trials should clarify the impact of preoperative breast MR imaging on clinical outcomes.

Background The functional range of motion (fROM) of the metacarpophalangeal (MCP) joints during the performance of activities of daily living (ADL) has not yet been established. This study aimed to determine the fROM of all five digits and verify the accuracy and reproducibility of dynamic angle measurement using a single-axis electric goniometer (EG) during ADL movements of the hand. Methods This was a cross-sectional study. In EG suitability testing, we first confirmed the angles of a three-dimensional calibration device 10 times, and then compared EG readings with those determined by tomosynthesis images. Next, we determined the fROM of the MCP joints by evaluating all five digits of the dominant hands of 10 healthy adults performing 16 ADL. Intra-rater reproducibility of MCP joint data during task performance was assessed in two healthy adults. Results Static measurements of the triangular object showed variance to be within one degree in 39 of 40 trials. Differences between angles measured by the EG and those depicted by radiograph were a range of plus or minus five degrees in 88 of 96 digits. The fROM values for the thumb and index, middle, ring, and little fingers were −7.5 to 35.3, 10.6 to 67.8, 4.0 to 79.9, 3.0 to 83.9, and 2.9–91.4 degrees of flexion, respectively. Flexion angle in the fROM of the index finger was significantly smaller than those of the ring and little fingers. The flexion and extension angles of the thumb were significantly smaller than those of the four ulnar fingers. The intra-rater correlation coefficients of two participants were high at 0.94 and 0.93, respectively. Conclusions The method adopted in this study exhibited excellent accuracy and reproducibility and was therefore considered suitable for the real-time establishment of fROM flexion-extension angles of the MCP joints for all five digits. Our data are useful as a target arc of motion in the treatment of MCP joint disease or injury.

Digital breast tomosynthesis (DBT) is a modified mammographic technique that overcomes some of the limitations of full-field digital mammography (2DDM) by eliminating the effect of overlapping breast tissue. In the UK, DBT is utilised in both the symptomatic setting and in breast screening assessment clinics. A literature search was conducted from 2010-2017 to ensure that the most recent developments in DBT technology, clinical applications, and assessment of its usefulness in breast screening were reviewed. Technological advances in DBT include the addition of synthetic 2D mammograms, which are generated from the DBT data set, and the use of DBT to guide vacuum-assisted biopsy and excisions. The units from each vendor vary in several aspects, which are detailed in this article. DBT improves diagnostic accuracy and reader confidence when identifying benign and malignant lesions. It has also been shown to be more accurate than 2DDM in assessing tumour size and in the assessment of multifocal tumours. In the screening setting, retrospective reader studies have shown that the addition of DBT to 2DDM showed equivalent or an improvement in sensitivity and specificity when compared to 2DDM alone. Many of these trials showed an increase in invasive cancer detection and a reduction in recall rates. Large prospective randomised controlled trials conducted in Europe and North America will evaluate effectiveness, practicalities, and cost implications of utilising DBT in routine breast screening practice.

In this study, we investigated an effective low-dose digital tomosynthesis (DTS) where a multislit collimator placed between the X-ray tube and the patient oscillates during projection data acquisition, partially blocking the X-ray beam to the patient thereby reducing the radiation dosage. We performed a simulation using the proposed DTS with two sets of multislit collimators both having a 50% duty cycle and investigated the image characteristics to demonstrate the feasibility of this proposed approach. In the simulation, all projections were taken at a tomographic angle of θ = ± 5 0 ° and an angle step of Δ θ = 2 ° . We utilized an iterative algorithm based on a compressed-sensing (CS) scheme for more accurate DTS reconstruction. Using the proposed DTS, we successfully obtained CS-reconstructed DTS images with no bright-band artifacts around the multislit edges of the collimator, thus maintaining the image quality. Therefore, the use of multislit collimation in current real-world DTS systems can reduce the radiation dosage to patients.

Early detection of breast cancers by mammography in conjunction with adjuvant therapy have contributed to reduction in breast cancer mortality. Mammography remains the ‘gold-standard’ for breast cancer screening, but is limited by tissue superposition. Digital breast tomosynthesis and more recently, dedicated breast computed tomography have been developed to alleviate the tissue superposition problem. However, all of these modalities rely upon x-ray attenuation contrast to provide anatomical images and there are ongoing efforts to develop and clinically translate alternative modalities. These emerging modalities could provide for new contrast mechanisms and may potentially improve lesion detection and diagnosis. In this article, several of these emerging modalities are discussed with a focus on technologies that have advanced to the stage of in vivo clinical evaluation.

Background and Objective Breast density at mammography has been used as markers of breast cancer risk. However, newly introduced tomosynthesis and computer-aided quantitative method could provide more reliable breast density evaluation. Methods In the experiment, 98 tomosynthesis image volumes were obtained from 98 women. For each case, an automatic skin removal was used and followed by a fuzzy c-mean (FCM) classifier which separated the fibroglandular tissues from other tissues in breast area. Finally, percent of breast density and breast volume were calculated and the results were compared with MRI. In addition, the percent of breast density and breast area of digital mammography calculated using the software Cumulus (University of Toronto, Toronto, ON, Canada.) were also compared with 3-D modalities. Results Percent of breast density and breast volume, which were computed from tomosynthesis, MRI and digital mammography were 17.37% ± 4.39% and 607.12 cm3 ± 323.01 cm3, 20.3% ± 8.6% and 537.59 cm3 ± 287.74 cm3, and 12.03% ± 4.08%, respectively. There were significant correlations on breast density as well as volume between tomosynthesis and MRI (R = 0.482 and R = 0.805), tomosynthesis and breast density with breast area of digital mammography (R = 0.789 and R = 0.877), and MRI and breast density with breast area of digital mammography (R = 0.482 and R = 0.857) (all P values Conclusions Breast density and breast volume evaluated from tomosynthesis, MRI and breast density and breast area of digital mammographic images have significant correlations and indicate that tomosynthesis could provide useful 3-D information on breast density through proposed method.

In recent digital tomosynthesis (DTS), iterative reconstruction methods are often used owing to the potential to provide multiplanar images of superior image quality to conventional filtered-backprojection (FBP)-based methods. However, they require enormous computational cost in the iterative process, which has still been an obstacle to put them to practical use. In this work, we propose a new DTS reconstruction method incorporated with a dual-resolution voxelization scheme in attempt to overcome these difficulties, in which the voxels outside a small region-of-interest (ROI) containing target diagnosis are binned by 2 × 2 × 2 while the voxels inside the ROI remain unbinned. We considered a compressed-sensing (CS)-based iterative algorithm with a dual-constraint strategy for more accurate DTS reconstruction. We implemented the proposed algorithm and performed a systematic simulation and experiment to demonstrate its viability. Our results indicate that the proposed method seems to be effective for reducing computational cost considerably in iterative DTS reconstruction, keeping the image quality inside the ROI not much degraded. A binning size of 2 × 2 × 2 required only about 31.9% computational memory and about 2.6% reconstruction time, compared to those for no binning case. The reconstruction quality was evaluated in terms of the root-mean-square error (RMSE), the contrast-to-noise ratio (CNR), and the universal-quality index (UQI).

After spine fusion surgery, it is difficult to evaluate the spinal canal and nerve roots using magnetic resonance imaging (MRI) because of metallic implant-related artifacts. Digital tomosynthesis is a new radiographic technique that can acquire tomographic images with reduced metallic artifact effects compared with MRI. We report a case demonstrating the visualization of nerve roots nearby metallic implants using dynamic tomosynthesis-radiculography (DTRG) after spinal fusion surgery. A 77-year-old man, who 3 years earlier underwent spine fusion surgery at L3–L5, presented complaining of newly-onset low back pain and radicular symptoms in the right fifth lumbar (L5) nerve root area. His symptoms were exacerbated when he stood upright. We suspected right L5 nerve root radiculopathy, but MRI could not depict any lesion of the nerve root because of metallic implant-related artifacts. We performed DTRG at the right L5 nerve root with the patient in both prone and upright positions. The right L5 nerve root was detected clearly, and nerve root compression at the foramina when the patient was upright was exacerbated more than when the patient was in a prone position. DTRG is helpful to diagnose lumbar foraminal stenosis nearby metallic implants after spine fusion surgery.

PURPOSE/OBJECTIVE(S) Many real-time guidance technologies for lung SBRT use surrogates of tumor motion. Direct imaging of the lung tumor may improve safety and efficacy of treatments, but the visibility of lung tumors with in-room biplane radiography is insufficient. We used simulations to assess the potential of in-room biplane tomosynthesis as an alternative. MATERIALS/METHODS Biplane tomosynthesis is envisioned as an in-place upgrade to biplane radiography. The envisioned system can be used either for radiography with a large field of view, or tomosynthesis with a small field of view. When tomosynthesis is desired, nine x-ray sources are energized simultaneously. Each x-ray source is positioned and collimated so that the detector receives all nine images in adjacent, non-overlapping sectors of the detector. We assume a 40 cm flat panel detector and 1.5x magnification, yielding an 8.8 cm square field of view. We selected 50 CT cases from the NSCLC Radiomics dataset with Stage I cancer and GTV diameters less than 5 cm as representative of lung SBRT cases. Simulated images of both in-room tomosynthesis and in-room radiography were produced using forward projection with dose of 0.3 mAs. Two thoracic radiation oncologists evaluated these images on a 4-point scale as follows: 1, tumor not visible; 2, visualization inadequate for motion management; 3, visualization adequate for motion management; 4, visualization excellent for motion management. The primary endpoint was the fraction of cases under each modality with scores of 3 or above. The cases were read in randomized order in two sessions spaced one week apart. Tomosynthesis also has potential for real-time imaging because all sources are energized simultaneously, but this capability could not be tested in static datasets. RESULTS On average, the two readers found 28% (range, 18-38%) of radiography images and 50% of tomosynthesis images (range, 48-52%) adequate or excellent for motion management. The average scores for radiography and tomosynthesis were 2.0 and 2.4 out of 4, respectively. The two readers agreed exactly for 54% of the images and disagreed by 1 point for 43% of the images. Tomosynthesis did not show a selective advantage for tumors larger or smaller than the median tumor volume of 7 cc. CONCLUSION In-room tomosynthesis has the potential to provide a fiducial-free mechanism for visualizing lung tumors while breathing. Nearly twice as many tumors were rated adequate for motion management using tomosynthesis when compared to radiography, but half of the tumors were rated inadequate using either modality. AUTHOR DISCLOSURE S.S. Hsieh: None. L.W. Ng: None. M. Cao: Research Grant; NIH. Honoraria; Varian Medical Systems Pacific Inc., ViewRay Inc, Varian Medical System Inc. Consultant; Varian Medical System, Guidepoint Inc. Travel Expenses; Varian Medical Systems Pacific Inc., Varian Medical System Inc.; Medical Dosimetrist Certification Board. Chair; AAPM.P. Lee: Research Grant; Viewray, Varian Inc., AstraZeneca, Inc. Honoraria; Viewray, Varian Inc., AstraZeneca, Inc. Consultant; Viewray, Varian Inc. Speaker's Bureau; AstraZeneca, Inc. Advisory Board; AstraZeneca, Inc. Travel Expenses; Viewray, Varian Inc.; Committee Co-Chair.

In the engineering processes of medical 3D radiographic scanner, detailed design elaborates each aspect of the device with complete descriptions, which may include operating parameters as well as the scanner specifications. For assessing the developments mathematically and objectively, task-based approaches are advocated for the optimization of image quality through the scanner design and imaging parameters. In this paper, we present a framework for assessing tomosynthesis scanner performance in lung lesion signal detectability through imaging parameters such as projection frames, lesion depths and anatomical background by using Hotelling observer (HO). Moreover, a channelized Hotelling observer (CHO) with efficient choices of non-linear iterative partial least squares (NIPALS) channels is implemented to reduce the large data dimensionality for computations. Area under the receiver operating characteristic curve (AUC) is computed as an objective figure-of-merit for the performance measurement that described the entire imaging chain. The presented framework is validated with our laboratory x-ray scanner and an anthropomorphic chest phantom. In our result, the performance is evaluated as functions of AUC to the imaging parameters. Performance map shows 5 mm lung lesion detectability is worsened with cardiac projection-overlapping. Scanner performance is highly related to anatomical structures at the image background. The developed framework has presented its value on assess tomosynthesis scanner performance through anthropomorphic phantom imaging. It can be an objective method for determining scanner detailed design and imaging parameters.

This paper presents a comparative study of five different imaging techniques. These techniques play a very important role in detection of abnormalities in the masses by screening the part of our interest. Out of these, Tomosynthesis, which is a 3D imaging technique, allows detection of smaller tumors and smaller microcalcifications than the 2D images. Using this technique, screening can be done at a very small angle, which helps in acquiring the image of overlapping masses. Compared to all other techniques, Tomosynthesis requires less radiation doses.

Purpose To assess the utility and pathological results from DBT VAB for lesions occult on 2D mammography and breast ultrasound (US). Materials and methods A retrospective review of 1116 consecutive stereotactic biopsies was performed over 27 months. DBT VAB was performed for 38 non-calcified lesions which were solely detected using DBT. Imaging findings and pathology results were reviewed. Results Pathologic findings were malignant in 8 of 38 lesions [masses (5) and distortion (3)]. High-risk findings found in 14 lesions. Conclusion DBT VAB is easily performed and the majority of cases yield actionable pathologies. Therefore, perform DBT VAB primarily when available.

An important limitation of conventional two-dimensional mammography is the overlap of dense breast tissue obscuring masses. Digital breast tomosynthesis (DBT) has emerged as a mammographic technology that overcomes this limitation and is considered an overall better mammogram. DBT has been shown to detect significantly more breast cancer than conventional two-dimensional mammography, and to decrease the number of callbacks for diagnostic evaluation from screening mammography. Usually the callback evaluation is deemed to be overlap of tissue requiring no further management. DBT is used in the screening and diagnostic setting, and for guidance of wire localization or core biopsy, performing more accurately in the dense breast.

BACKGROUND Research on radiographic detection of proximal caries has shown high specificity but low sensitivity, especially for early caries lesions. Stationary intraoral tomosynthesis (s-IOT) shows promise in caries detection, utilizing multibeam carbon nanotube source array technology and a direct intraoral detector to acquire images at similar radiation dose to standard bitewings and generating stacks of parasagittal image slices with an iterative reconstruction algorithm. OBJECTIVE(S) This study aimed to compare the diagnostic accuracy of s-IOT and conventional digital bitewing modalities for the detection of proximal caries lesions. STUDY DESIGN Extracted permanent posterior teeth (n = 64) with proximal surfaces scored between 0 and 4 in the International Caries Detection Assessment System were mounted in phantom heads for imaging. Eight observers, each with 2 or more years of radiology specialty training, scored surfaces on a 5-point Likert scale for caries presence and depth using s-IOT images and digital bitewings, in a standardized viewing format. Fifty percent of specimens will be repeated for intra-examiner reliability assessment. Results will be compared with a histologic gold standard and analyzed by logistic regression and receiver operating curve (Az value). The study is currently in progress, with final results expected by August 2020. RESULTS Pilot test results with 3 observers showed s-IOT to have a sensitivity of 49.6% and specificity of 86.1%, with interobserver agreement of 0.433. The conventional bitewing modality had a sensitivity of 47.9% and specificity of 83.3%, with interobserver agreement of 0.380. DISCUSSION/CONCLUSIONS Based on preliminary data, the 2 imaging modalities showed small differences between sensitivity, specificity, and interobserver kappa reliability, indicating that s-IOT is comparable to digital bitewings for the detection of proximal caries.

Purpose To compare the performance in breast lesion characterization of one-view mediolateral (MLO) digital mammography plus digital breast tomosynthesis (DM-DBT) versus one-view craniocaudal (CC) DM-DBT versus two-view DM-DBT. Materials and methods The institutional review board approved this retrospective study conducted on 138 women from the population of a previous prospective multicenter study, with 69 consecutive patients with benign or high-risk lesions and 69 randomized patients with breast cancer, all confirmed at pathology. Four radiologists (two senior and two junior) blinded to the clinical, mammographic and pathological data independently reviewed the MLO DM-DBT views, the CC DM-DBT views and the MLO + CC DM-DBT views using the American College of Radiology Breast Imaging-Reporting and Data System criteria for index lesion characterization. Areas under the receiver were calculated and compared for each reader and imaging protocol. Results No significant differences in breast cancer characterization were observed between single MLO and CC views for all the readers. The added value of a second view was statistically significant for characterization in pooled data and for junior readers but not for senior readers (p ranging from 0.15 to 0.57 depending on the view and the senior reader). Finally, in 4 breast cancer cases, lesions were only detectable on the CC DM-DBT view in two cases and on the MLO DM-DBT view in the two other cases. Conclusion Our results support the use of two-view DM-DBT for breast lesion characterization when the readers are inexperienced. There is no significant difference between CC and MLO views when diagnosis is performed with one view.

BACKGROUND The implementation of preventive strategies has aided in the noticeable decline of caries prevalence in developed countries. With the reduction of caries prevalence, there is a higher demand for more sensitive and accurate caries detection modalities. In this study we explore the utility of stationary intraoral tomosynthesis (sIOT) in occlusal caries detection. OBJECTIVE(S) In this ex vivo diagnostic accuracy study we aim to evaluate the accuracy and assess the sensitivity, specificity, and area under the ROC curve of s-IOT in detecting primary occlusal caries and to compare the results with digital intraoral bitewings, cone beam computed tomography (CBCT), and the histologic standard reference. STUDY DESIGN Sixty de-identified extracted human teeth were selected. The teeth selected included unrestored premolar or molar teeth with fully formed roots. The occlusal surfaces exhibited a status that ranged from sound to carious lesions extending into the inner third of the dentin. Teeth with developmental defects such as hypoplasia or fluorosis were excluded from the study. The teeth were coded and randomly mounted using polyvinyl siloxane (PVS) in dental dentoforms and imaged with the 3 imaging modalities (s-IOT, IO bitewings, and CBCT). A reader study was conducted in which 3 calibrated observers were presented with the 3 imaging modalities. A wash-out period of at least 2 weeks was allowed between sessions, with 1 modality displayed per session. The readers were asked to assess their confidence in caries presence using a 5-point Likert scale and to assess caries depth. After imaging, the teeth were sectioned and histologic examination was completed to establish the ground truth reference. RESULTS Accuracy, sensitivity, specificity, and area under the ROC curve of the 3 radiographic modalities will be compared with the histologic standard reference. Results are pending final statistical analysis.

Digital tomosynthesis system (DTS) has been increasingly used in chest X-ray imaging with a limited-projection angle image reconstruction method. Image reconstruction methods in chest digital tomosynthesis (CDT) have fundamental impacts on image characteristics. Among these methods, iterative algorithm provides the additional benefits of chest X-ray imaging. However, there is almost no research that maximum-likelihood expectation-maximization (MLEM) method in CDT system. Thus, the purpose of this study was (1) to develop MLEM reconstruction algorithm based on CDT system and (2) to quantitatively compare the image characteristics with respect to the total angular range and iteration number as applied this system. For that purpose, we performed both simulation using MATLAB program and experimental studies. Tomography was performed linearly with a maximum ±30° total angular range and then we acquired Shepp-Logan and PMMA-Aluminum (Al) phantom images using 120 kVp X-ray source for simulation and experiment, respectively. We evaluated and compared the MLEM reconstructed image characteristics using root-mean-square error (RMSE) and signal difference-to-noise ratio (SDNR) with various total angular ranges and iteration numbers. According to the results, we can acquire improved image characteristics as the number of iterations and the number of projections increased. Also, we found optimized iteration number for 20 iteration numbers in our CDT system geometry because there were few changes of image characteristics over 20 iteration numbers. In conclusion, we have presented usefulness and effectiveness of developed CDT image reconstruction algorithm.

Conventional digital tomosynthesis (DTS) based on the filtered-backprojection (FBP) reconstruction requires full field-of-view scan and also relatively dense projections, which results in still high dose for medical imaging purposes. In this work, to overcome these difficulties, we propose a new type of DTS examinations, the so-called scout-view assisted interior DTS (iDTS), in which the x-ray beam span covers only a small region-of-interest (ROI) containing target diagnosis with the help of some scout views and they are used in the reconstruction to add additional information to interior ROI otherwise absent with conventional iDTS reconstruction methods. We considered an effective iterative algorithm based on compressed-sensing theory, rather than the FBP-based algorithm, for more accurate iDTS reconstruction. We implemented the proposed algorithm, performed a systematic simulation and experiment, and investigated the image characteristics. We successfully reconstructed iDTS images of substantially high accuracy and no truncation artifacts by using the proposed method, preserving superior image homogeneity, edge sharpening, and in-plane spatial resolution.