Proposed DRLs for mammography in Switzerland.

The aim of this study is to propose diagnostic reference levels (DRLs) values for mammography in Switzerland. For the data collection, a survey was conducted among a sufficient number of centres, including five University hospitals, several cantonal hospitals, and large private clinics, covering all linguistic regions of Switzerland to be representative of the clinical practice. The data gathered contained the mean glandular dose (MGD), the compressed breast thickness (CBT), the mammography model and the examination parameters for each acquisition. The data collected was sorted into the following categories: 2D or digital breast tomosynthesis (DBT) examination, craniocaudal (CC) or mediolateral oblique (MLO) projection, and eight categories of CBT ranging from 20 mm to 100 mm in 10 mm intervals. A total of 24 762 acquisitions were gathered in 31 centres on 36 mammography units from six manufacturers. The analysis showed that the data reflects the practice in Switzerland. The results revealed that the MGD is larger for DBT than for 2D acquisitions for the same CBT. From 20-30 mm to 90-100 mm of CBT, the 75th percentile of the MGD values obtained increased from 0.81 mGy to 2.55 mGy for 2D CC acquisitions, from 0.83 mGy to 2.96 mGy for 2D MLO acquisitions, from 1.22 mGy to 3.66 mGy for DBT CC acquisitions and from 1.33 mGy to 4.04 mGy for DBT MLO acquisitions. The results of the survey allow us to propose Swiss DRLs for mammography according to the examination type (2D/DBT), projection (CC/MLO) and CBT. The proposed values are very satisfactory in comparison with other studies.

[Practical guidelines in case of nipple discharge]. / Recommandations pratiques en cas d'écoulement mamelonnaire.

Nipple discharge is a frequent reason for women to consult their physician, led by the fear of cancer. Fortunately, almost 90 % of cases have a benign aetiology. The main challenge is to rule out any malignant pathology by collecting a detailed history and clinical exam in order to define a targeted imaging. The aim of this review is to facilitate the management of nipple discharge. The most common aetiologies of nipple discharge are described, along with a systematic clinical approach to exclude any underlying malignancy and minimize invasive examinations.

L'écoulement mamelonnaire est un motif fréquent de consultation, souvent par crainte d'un cancer. Heureusement, près de 90 % des écoulements mamelonnaires présentent une étiologie bénigne. L'enjeu principal est d'écarter toute pathologie maligne en procédant à une anamnèse et un examen cliniques détaillés afin de définir le type d'écoulement et prescrire des examens complémentaires ciblés. Cet article cherche à faciliter la prise en charge des écoulements mamelonnaires et décrit leurs étiologies les plus communes. Il propose une approche clinique systématique permettant d'exclure une cause maligne sous-jacente et de minimiser les examens invasifs.

[Mastalgia : management and state of the art]. / Mastodynies : prise en charge et connaissances actuelles.

This article tries to facilitate the management of mastalgia. During their lifetime most women will experience breast pain. Many of them will visit a physician for this purpose, often led by the fear of cancer. However, in the absence of other clinical signs such as a lump or nipple discharge, the risk of malignancy remains low. In addition to the patient's medical history and physical examination, an imaging may be necessary. The absence of clinical or radiological abnormalities suffices to reassure patients in most cases. The management of mastalgia is based mainly on diet and life-style changes, the use of a well-suited bra and topical anti-inflammatory medication. In the case of mastalgia not responding to first line treatments, the patient should be referred to a breast-care unit.

Cet article cherche à faciliter la prise en charge des mastodynies. Au cours de leur vie, la majorité des femmes présenteront des mastodynies. Nombreuses sont celles qui consulteront leur médecin à cet égard, souvent par crainte d'un cancer. Cependant, en l'absence d'autres signes cliniques comme une masse ou un écoulement mamelonnaire, le risque de malignité reste faible. Outre l'anamnèse et l'examen clinique, une imagerie peut s'avérer nécessaire. L'absence d'anomalies cliniques ou radiologiques permet de rassurer les patientes dans la majorité des cas. Le traitement reposera essentiellement sur des mesures hygiéno-diététiques, le port d'un soutien-gorge adapté et l'utilisation d'anti-inflammatoires topiques. En cas de mastodynies invalidantes et réfractaires aux anti-inflammatoires, la patiente devra être adressée pour un suivi spécialisé.

In Vivo Imaging-Based 3-Dimensional Pelvic Prototype Models to Improve Education Regarding Sexual Anatomy and Physiology.

BACKGROUND: Myths, misconceptions, and taboos about sexual anatomy and physiology are common and can affect sexual health and maintain harmful practices and beliefs. AIM: To construct a female and a preliminary male 3-dimensional (3D) pelvic model on the basis of in vivo imaging, which could be studied in sex education and clinical practice. METHODS: We retrospectively studied the images of 200 female pelvic magnetic resonance examinations and reviewed the literature to choose the optimum magnetic resonance imaging (MRI) protocol for the study of the clitoris and surrounding organs. We also conducted a cross-sectional study of 30 women who were undergoing a pelvic MRI. 15 women had undergone female genital mutilation/cutting involving the clitoris and 15 had not. The best-quality MRI images of 3 uncut and 1 cut clitoris, together with the principal surrounding pelvic organs, were selected to generate 3D reconstructions using dedicated software. The same software was used to reconstruct the anatomy of the penis and the principal surrounding pelvic organs, based on contrast-enhanced computer tomography images. Images of both models were exported in .stl format and cleaned to obtain single manifold objects in free, open source software. Each organ model was sliced and 3D printed. A preliminary feedback was collected from 13 potential users working in urology, gynaecology, sexual medicine, physiotherapy, and education. OUTCOMES: The main outcomes of this study are a kit of 3D pelvic models, 2-dimensional figures of female and male sexual anatomy, and files for 3D printing. RESULTS: We present a kit containing 3D models and 2-dimensional figures of female and male sexual anatomy, based on in vivo imaging and, feedbacks and suggestions received from potential users. CLINICAL TRANSLATION: Our kit can be used in anatomy and sex education among and by health professionals, teachers, sex educators, students, and the general population. STRENGTHS & LIMITATIONS: The strengths are that the models were based on in vivo imaging, can be dismantled/reassembled, and show analogous anatomic structures of the clitoris and the penis. The female models represent diversity, including women with female genital mutilation/cutting. The limitations are that the male model is preliminary and can be improved if based on an MRI; that imaging-based anatomic representations can differ from anatomic dissections; and that the models represent the sexual organs at rest or during an unknown state of arousal only. CONCLUSION: Our kit can be studied in anatomy, biology, and sex education, as well as in clinical practice. Abdulcadir J, Dewaele R, Firmenich N, et al. In Vivo Imaging-Based 3-Dimensional Pelvic Prototype Models to Improve Education Regarding Sexual Anatomy and Physiology. J Sex Med 2020;17:1590-1602.

Suspicion of appendicitis in pregnant women: emergency evaluation by sonography and low-dose CT with oral contrast.

OBJECTIVES: To evaluate non-intravenously enhanced low-dose computed tomography with oral contrast (LDCT) for the assessment of pregnant women with right lower quadrant pain, when magnetic resonance imaging (MRI) is not immediately available. METHODS: One hundred and thirty-eight consecutive pregnant women with acute abdominal pain were admitted in our emergency centre. Thirty-seven (27%) of them, with clinical suspicion of acute appendicitis, underwent abdominal ultrasonography (US). No further examination was recommended when US was positive for appendicitis, negative with low clinical suspicion or showed an alternative diagnosis which explained the clinical presentation. All other patients underwent LDCT (<2.5 mSv). Standard intravenously enhanced CT or MRI was performed when LDCT was indeterminate. RESULTS: Eight (22%) of 37 US exams were reported normal, 25 (67%) indeterminate, 1 (3%) positive for appendicitis, 3 (8%) positive for an alternative diagnosis. LDCT was obtained in 29 (78%) patients. It was reported positive for appendicitis in 9 (31%), for alternative diagnosis in 2 (7%), normal in 13 (45%) and indeterminate in 5 (17%). Further imaging (standard CT or MRI) showed appendicitis in 2 of these 5 patients, was truly negative in 1, indeterminate in 1 and falsely positive in 1. An appendicitis was confirmed at surgery in 12 (32%) of the 37 patients. The sensitivity and the specificity of the algorithm for appendicitis were 100% (12/12) and 92% (23/25), respectively. CONCLUSIONS: The proposed algorithm is very sensitive and specific for detection of acute appendicitis in pregnant women; it reduces the need of standard CTs when MRI is not available as second-line imaging. KEY POINTS: • In pregnant women, US is limited by an important number of indeterminate results • Low-dose CT can be used after an inconclusive US for the diagnosis of appendicitis in pregnant women • An algorithm integrating US and low-dose CT is highly sensitive and specific for appendicitis in pregnant women.

What is the diagnostic performance of 18-FDG-PET/MR compared to PET/CT for the N- and M- staging of breast cancer?

PURPOSE: To compare the diagnostic performance of 18-FDG-PET/MR and PET/CT for the N- and M- staging of breast cancer. METHODS AND MATERIALS: Two independent readers blinded to clinical/follow-up data reviewed PET/MR and PET/CT examinations performed for initial or recurrent breast cancer staging in 80 consecutive patients (mean age = 48 ± 12.9 years). The diagnostic confidence for lesions in the contralateral breast, axillary/internal mammary nodes, bones and other distant sites were recorded. Sensitivity, specificity, positive (PPV) and negative predictive values (NPV) were calculated. The standard of reference included pathology and/or follow-up > 12 months. RESULTS: Nine of 80 patients had bone metastases; 13/80 had other distant metastases, 44/80 had axillary, 9/80 had internal mammary and 3/80 had contralateral breast tumours. Inter-reader agreement for lesions was excellent (weighted kappa = 0.833 for PET/CT and 0.823 for PET/MR) with similar reader confidence for the two tests (ICC = 0.875). In the patient-per-patient analysis, sensitivity and specificity of PET/MRI and PET/CT were similar (p > 0.05). In the lesion-per-lesion analysis, the sensitivity of PET/MR and PET/CT for bone metastases, other metastases, axillary and internal mammary nodes, contralateral tumours and all lesions together was 0.924 and 0.6923 (p = 0.0034), 0.923 and 0.923 (p = 1), 0.854 and 0.812 (p = 0.157), 0.9 and 0.9 (p = 1), 1 and 0.25 (p = 0.083), and 0.89 and 0.77 (p = 0.0013) respectively. The corresponding specificity was 0.953 and 1 (p = 0.0081), 1 and 1 (p = 1), 0.893 and 0.92 (p = 0.257), 1 and 1 (p = 1), 0.987 and 0.99 (p = 1) and 0.96 and 0.98 (p = 0.0075) respectively. CONCLUSIONS: Reader confidence, inter-reader agreement and diagnostic performance per patient were similar with PET/MR and PET/CT. However, for all lesions together, PET/MR had a superior sensitivity and lower specificity in the lesion-per-lesion analysis. KEY POINTS: • N and M breast cancer staging performance of PET/MR and PET/CT is similar per patient. • In a lesion-per-lesion analysis PET/MR is more sensitive than PET/CT especially for bone metastasis. • Readers' diagnostic confidence is similar for both tests.

Cell Spillage after Contained Electromechanical Morcellation Using a Specially Designed In-Bag System for Laparoscopic Myomectomy: Prospective Cohort Pilot Study.

STUDY OBJECTIVE: Few reports have investigated the use of endoscopic retrieval bags in the context of laparoscopic myomectomy with electromechanical morcellation. We performed a leak test of a specially designed endoscopic bag system in women undergoing laparoscopic myomectomy with contained electromechanical morcellation. DESIGN CLASSIFICATION: Prospective study. SETTING: University hospital. PATIENTS: Thirty-one women undergoing laparoscopic myomectomy with contained electromechanical morcellation. INTERVENTIONS: Electromechanical morcellation was introduced for large specimen extraction during laparoscopic procedures. Complications such as retained/disseminated parasitic tissue were documented. MEASUREMENTS AND MAIN RESULTS: Systematic peritoneal washings were performed at 3 specific times: at baseline, T1, once the peritoneal cavity was accessed laparoscopically; T2, when the myometrial incision was closed after myomectomy; and T3, after contained electromechanical morcellation. After retrieval of the endoscopic bag from the abdominal cavity, visual inspection and water test on the bag with NaCl infiltration were performed to detect leaks attributed to intraoperative perforations. A pathologist performed cytologic analyses on the 3 washings. The mean endoscopic bag procedure duration was 9 minutes. The use of a specially designed endoscopic bag system was found to be easy in 45% of cases, and no complications were reported. Cytologic washings were positive for smooth muscle cell detection in 8 cases (25.8%) at T2 and 3 cases (9.7%) at T3. All positive cases at T3 already had detectable smooth muscle cells at T2. After retrieval from the abdominal cavity, perforations on the optic access of the endoscopic bag were observed in 3 cases. CONCLUSION: The results from this pilot study are encouraging. The use of a specially designed endoscopic bag system could be an adjuvant to reduce the risk of disseminating cells during myomectomy.

Impact of iterative reconstructions on objective and subjective emphysema assessment with computed tomography: a prospective study.

OBJECTIVES: To prospectively evaluate the impact of iterative reconstruction (IR) algorithms on pulmonary emphysema assessment as compared to filtered back projection (FBP). METHODS: One hundred ten unenhanced chest CT examinations were obtained on two different scanners. Image reconstructions from a single acquisition were done with different levels of IR and compared with FBP on the basis of the emphysema index (EI), lung volume and voxel densities. Objective emphysema assessment was performed with 3D software provided by each manufacturer. Subjective assessment of emphysema was performed as a blinded evaluation. Quantitative and subjective values were compared using repeated ANOVA analysis, Bland-Altman analysis and Kendall's coefficient of concordance (W). RESULTS: Lung volumes are stable on both units, throughout all IR levels (P ≥ 0.057). EI significantly decreases on both units with the use of any level of IR (P < 0.001). The highest levels of IR are responsible for a decrease of 33-36 % of EI. Significant differences in minimal lung density are found between the different algorithms (P < 0.003). Intra- and inter-reader concordance for emphysema characterisation is generally good (W ≥ 0.77 and W ≥ 0.86, respectively). CONCLUSIONS: Both commercially available IR algorithms used in this study significantly changed EI but did not alter visual assessment compared to standard FBP reconstruction at identical radiation exposure. KEY POINTS: • Objective quantification of pulmonary emphysema is sensitive to iterative reconstructions • Subjective evaluation of pulmonary emphysema is not influenced by iterative reconstructions • Consistency in reconstruction algorithms is of paramount importance for pulmonary emphysema monitoring.

Fat suppression techniques for breast MRI: Dixon versus spectral fat saturation for 3D T1-weighted at 3 T.

OBJECTIVE: To compare two fat suppression techniques used for 3D T1-weighted sequence in breast MRI (magnetic resonance imaging), namely Dixon versus spectral fat saturation (fat sat). MATERIALS AND METHODS: All breast MRI examinations performed in a Philips 3 T unit between March 2013 and October 2015 including either a Dixon or a fat sat sequence were retrospectively analyzed. The examinations were subjectively evaluated by two independent experienced readers in a scale of 5 for overall quality of fat suppression, homogeneity of fat suppression, definition of anatomic structures and focal lesions, diagnostic confidence for axillary and internal mammary regions and the presence of artifacts, 1 corresponding to excellent and 5 to non-diagnostic quality. Contrast-to-noise-ratio (CNR) measurements for muscle and focal lesions were also performed. RESULTS: Overall 161 women (mean age 51.6 ± 12.0 years) underwent 189 MR examinations, 113 with the fat saturation and 76 with the Dixon sequence. Interobserver variability was good (kappa = 0.757). In all subjectively evaluated parameters, the Dixon sequence was superior to the fat sat (p < 0.05). Mean values of CNR for muscle and focal lesions were 9.98 (±4.2), 17.9 (±7.53) for the fat sat and 18.3 (±10.4) and 29.3 (±14.1) for the Dixon sequence, respectively (p < 0.001). CONCLUSION: 3D T1 Dixon sequence is superior to fat sat for dedicated breast MRI at 3 T, in terms of efficiency of fat suppression and image quality with the added advantage of optimal exploration of the axillary areas.

Sexual Anatomy and Function in Women With and Without Genital Mutilation: A Cross-Sectional Study.

INTRODUCTION: Female genital mutilation (FGM), the partial or total removal of the external genitalia for non-medical reasons, can affect female sexuality. However, only few studies are available, and these have significant methodologic limitations. AIM: To understand the impact of FGM on the anatomy of the clitoris and bulbs using magnetic resonance imaging and on sexuality using psychometric instruments and to study whether differences in anatomy after FGM correlate with differences in sexual function, desire, and body image. METHODS: A cross-sectional study on sexual function and sexual anatomy was performed in women with and without FGM. Fifteen women with FGM involving cutting of the clitoris and 15 uncut women as a control group matched by age and parity were prospectively recruited. Participants underwent pelvic magnetic resonance imaging with vaginal opacification by ultrasound gel and completed validated questionnaires on desire (Sexual Desire Inventory), body image (Questionnaire d'Image Corporelle [Body Image Satisfaction Scale]), and sexual function (Female Sexual Function Index). MAIN OUTCOME MEASURES: Primary outcomes were clitoral and bulbar measurements on magnetic resonance images. Secondary outcomes were sexual function, desire, and body image scores. RESULTS: Women with FGM did not have significantly decreased clitoral glans width and body length but did have significantly smaller volume of the clitoris plus bulbs. They scored significantly lower on sexual function and desire than women without FGM. They did not score lower on Female Sexual Function Index sub-scores for orgasm, desire, and satisfaction and on the Questionnaire d'Image Corporelle but did report significantly more dyspareunia. A larger total volume of clitoris and bulbs did not correlate with higher Female Sexual Function Index and Sexual Desire Inventory scores in women with FGM compared with uncut women who had larger total volume that correlated with higher scores. CONCLUSION: Women with FGM have sexual erectile tissues for sexual arousal, orgasm, and pleasure. Women with sexual dysfunction should be appropriately counseled and treated.

Clinical utility of 18F-FDG-PET/MR for preoperative breast cancer staging.

OBJECTIVE: To evaluate the performance of 18F-fluorodeoxyglucose (FDG) positron emission tomography magnetic resonance imaging (PET/MR) for preoperative breast cancer staging. METHODS: Preoperative PET/MR exams of 58 consecutive women with breast cancer were retrospectively reviewed. Histology and mean follow-up of 26 months served as gold standard. Four experienced readers evaluated primary lesions, lymph nodes and distant metastases with contrast-enhanced MRI, qualitative/quantitative PET, and combined PET/MR. ROC curves were calculated for all modalities and their combinations. RESULTS: The study included 101 breast lesions (83 malignant, 18 benign) and 198 lymph node groups, (34 malignant, 164 benign). Two patients had distant metastases. Areas under the curve (AUC) for breast cancer were 0.9558, 0.8347 and 0.8855 with MRI, and with qualitative and quantitative PET/MR, respectively (p = 0.066). Sensitivity for primary cancers with MRI and quantitative PET/MR was 100 % and 77 % (p = 0.004), and for lymph nodes 88 % and 79 % (p = 0.25), respectively. Specificity for MRI and PET/MR for primary cancers was 67 % and 100 % (p = 0.03) and for lymph nodes 98 % and 100 % (p = 0.25). CONCLUSIONS: In breast cancer patients, MRI alone has the highest sensitivity for primary tumours. For nodal metastases, both MRI and PET/MR are highly specific. KEY POINTS: • MRI alone and PET/MR have a similar overall diagnostic performance. • MRI alone has a higher sensitivity than PET/MR for local tumour assessment. • Both MRI and PET/MR have a limited sensitivity for nodal metastases. • Positive lymph nodes on MRI or PET/MR do not require presurgical biopsy.

Image quality of low mA CT pulmonary angiography reconstructed with model based iterative reconstruction versus standard CT pulmonary angiography reconstructed with filtered back projection: an equivalency trial.

OBJECTIVE: To determine whether CT pulmonary angiography (CTPA) using low mA setting reconstructed with model-based iterative reconstruction (MBIR) is equivalent to routine CTPA reconstructed with filtered back projection (FBP). METHODS: This prospective study was approved by the institutional review board and patients provided written informed consent. Eighty-two patients were examined with a low mA MBIR-CTPA (100 kV, 20 mA) and 82 patients with a standard FBP-CTPA (100 kV, 250 mA). Region of interests were drawn in nine pulmonary vessels; signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. A five-point scale was used to subjectively evaluate the image quality of FBP-CTPA and low mA MBIR-CTPA. RESULTS: Compared to routine FBP-CTPA, low mA MBIR-CTPA showed no differences in the attenuation measured in nine pulmonary vessels, higher SNR (56 ± 19 vs 43 ± 20, p < 0.0001) and higher CNR (50 ± 17 vs 38 ± 18, p < 0.0001) despite a dose reduction of 93 % (p < 0.0001). The subjective image quality of low mA MBIR-CTPA was quoted as diagnostic in 98 % of the cases for patient with body mass index less than 30 kg/m(2). CONCLUSION: Low mA MBIR-CTPA is equivalent to routine FBP-CTPA and allows a significant dose reduction while improving SNR and CNR in the pulmonary vessels, as compared with routine FBP-CTPA. KEY POINTS: • Low mA MBIR-CTPA is equivalent to routine FBP-CTPA. • MBIR-CTPA may be achieved with drastic (93 %) dose reduction. • Low mA MBIR-CTPA should be studied in the setting of suspected PE.

Urinary stone detection and characterisation with dual-energy CT urography after furosemide intravenous injection: preliminary results.

OBJECTIVES: To investigate the added advantage of IV furosemide injection and the subsequent urine dilution in the detection of urinary calculi in the excretory phase of dual-source dual-energy (DE) computed tomography (CT) urography, and to investigate the feasibility of characterising the calculi through diluted urine. METHODS: Twenty-three urinary calculi were detected in 116 patients who underwent DECT urography for macroscopic haematuria with a split bolus two- or three-acquisition protocol, including a true unenhanced series and at least a mixed nephrographic excretory phase. Virtual unenhanced images were reconstructed from contrast-enhanced DE data. Calculi were recorded on all series and characterised based on their X-ray absorption characteristics at 100 kVp and 140 kVp in both true unenhanced and nephrographic excretory phase series. RESULTS: All calculi with a diameter more than 2 mm were detected in the virtual unenhanced phase and in the nephrographic excretory phase. Thirteen of these calculi could be characterised in the true unenhanced phase and in the mixed nephrographic excretory phase. The results were strictly identical for both phases, six of them being recognised as non-uric acid calculi and seven as uric acid calculi. CONCLUSIONS: Mixed nephrographic excretory phase DECT after furosemide administration allows both detection and characterisation of clinically significant calculi, through the diluted urine. KEY POINTS: • Urinary tract stones can be detected on excretory phase through diluted urine. • Urinary tract stone characterisation with dual-energy CT (DECT) is possible through diluted urine. • A dual energy split-bolus CT urography simultaneously enables urinary stone detection and characterisation.

Diagnosis of urothelial tumors with a dedicated dual-source dual-energy MDCT protocol: preliminary results.

OBJECTIVE: The purpose of this study was to evaluate the diagnostic performance of a dedicated dual-source dual-energy MDCT (DECT) protocol for the detection of urothelial tumors. MATERIALS AND METHODS: A DECT protocol including furosemide and split-bolus contrast injection was used in 69 consecutive patients with suspected abnormalities of the urinary system. Thirteen patients were excluded because there was no follow-up available. In 56 patients, the final diagnosis was proven with endoscopy, biopsy, or follow-up and included urothelial tumors (n = 37) in 16 patients, other urinary tract pathologies (n = 9) in eight patients, and absence of lesions of the collecting system in 32 patients. The image series consisted of a dual-energy true unenhanced series, 35-second arterial phase, and 8-minute nephrographic-excretory phase and were analyzed retrospectively. True enhancement of all detected lesions was measured. On the basis of the DECT data of the contrast-enhanced images, virtual unenhanced series were created and iodine concentration was calculated using commercially available software. The attenuation difference between virtual unenhanced and contrast-enhanced images (virtual enhancement) was measured. CT findings were compared with the final diagnosis. RESULTS: Urothelial tumors were identified on 35-second series, 8-minute series, and both series combined, with sensitivity of 91.9% (95% CI, 78.1-98.2%), 83.4% (68.0-93.8%), and 97.3% (85.8-100%), respectively. Urothelial tumors showed stronger virtual enhancement (p = 0.02) and higher iodine concentration (p = 0.03) than lesions of other origin. Distinction between urothelial tumors and nontumoral lesions was possible with sensitivity of 91.9% (78.1-98.2%) when using a threshold concentration of at least 1.0 mg I/mL. CONCLUSION: Dual phase DECT with virtual unenhanced imaging and iodine concentration measurement appears to be a useful diagnostic test for urothelial tumors.

Model-based iterative reconstruction versus adaptive statistical iterative reconstruction in low-dose abdominal CT for urolithiasis.

OBJECTIVE: The purpose of this study was to determine whether there is added benefit to model-based iterative reconstruction as compared with adaptive statistical iterative reconstruction on low-dose abdominal CT in the clinical context of known or suspected urolithiasis. MATERIALS AND METHODS: Fifty-three consecutive patients (35 men, 18 women; mean [SD] age, 52.3 ± 16.6 years) underwent unenhanced low-dose abdominal CT for detection or follow-up of urinary tract stones. Ureteral definition was evaluated subjectively by two blinded readers who scored it from 1 (excellent definition) to 4 (not distinguishable) and objectively by calculating contrast-to-noise ratio (CNR) for soft tissue and fat on a standard 40% adaptive statistical iterative reconstruction and on the corresponding model-based iterative reconstruction series. The position, maximal density, and diameter on the axial plane of stones were also evaluated on both series. RESULTS: There was an almost perfect agreement (κ = 0.872) between readers for subjective evaluation of ureteral definition. The ureteral definition was significantly better for the model-based iterative reconstruction series (mean [SD] score, 1.998 ± 0.839) compared with adaptive statistical iterative reconstruction (mean score, 2.536 ± 0.799) (p < 0.0001). Mean CNR was significantly better on the model-based iterative reconstruction (17.82 ± 4.84) compared with adaptive statistical iterative reconstruction (6.066 ± 1.985) (p < 0.0001). Sixty-nine stones were found in total. Their maximal density measured from model-based iterative reconstruction was significantly higher (754.4 ± 376.5 HU) than that measured from adaptive statistical iterative reconstruction (559.4 ± 352.4 HU) (p < 0.0001). Size of stones was overevaluated on model-based iterative reconstruction (mean diameter, 4.91 ± 2.61 mm) compared with adaptive statistical iterative reconstruction (4.52 ± 2.63 mm) (p < 0.0001). CONCLUSION: Model-based iterative reconstruction of low-dose abdominal CT can offer significantly better ureteral definition than adaptive statistical iterative reconstruction, and its systematic use could thus be recommended. However, it has the tendency to systematically overevaluate the stones' densities and sizes.

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

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. METHODS: Unenhanced chest CT images of 42 patients acquired with ULD-CT were compared with images obtained with SDD-CT or LDD-CT in the same examination. Noise measurements and image quality, based on conspicuity of chest lesions on all CT data sets were assessed on a five-point scale. RESULTS: The radiation dose of ULD-CT was 0.16 ± 0.006 mSv compared with 11.2 ± 2.7 mSv for SDD-CT (P < 0.0001) and 2.7 ± 0.9 mSv for LDD-CT. Image quality of ULD-CT increased significantly when using MBIR compared with FBP or ASIR (P < 0.001). ULD-CT reconstructed with MBIR enabled to detect as many non-calcified pulmonary nodules as seen on SDD-CT or LDD-CT. However, image quality of ULD-CT was clearly inferior for characterisation of ground glass opacities or emphysema. CONCLUSION: Model-based iterative reconstruction allows detection of pulmonary nodules with ULD-CT with radiation exposure in the range of a posterior to anterior (PA) and lateral chest X-ray.

The Clinical Added Value of Breast Cancer Imaging Using Hybrid PET/MR Imaging.

Dedicated MR imaging is highly performant for the evaluation of the primary lesion and should regularly be added to whole-body PET/MR imaging for the initial staging. PET/MR imaging is highly sensitive for the detection of nodal involvement and could be combined with the high specificity of axillary second look ultrasound for the confirmation of the N staging. For M staging, with the exception of lung lesions, PET/MR imaging is superior to PET/computed tomography, at half the radiation dose. The predictive value of multiparametric imaging with PET/MR imaging holds promise to improve through radiomics and artificial intelligence.

A new MDCT technique for the detection and anatomical exploration of urogenital fistulas.

OBJECTIVE: We tested a new MDCT technical protocol, combining i.v. and intravesical positive contrast agent and intravaginal neutral contrast agent, that optimizes exploration of urogenital fistulas. We examined three patients (four CT examinations in total) with this technique and proved that a preexisting subtle ureterovaginal fistula that was under treatment was still present, though clinically silent. CONCLUSION: The proposed MDCT examination protocol provides important information to help detect subtle urogenital fistulas.

Diffusion-Weighted MRI in the Genitourinary System.

Diffusion weighted imaging (DWI) constitutes a major functional parameter performed in Magnetic Resonance Imaging (MRI). The DW sequence is performed by acquiring a set of native images described by their b-values, each b-value representing the strength of the diffusion MR gradients specific to that sequence. By fitting the data with models describing the motion of water in tissue, an apparent diffusion coefficient (ADC) map is built and allows the assessment of water mobility inside the tissue. The high cellularity of tumors restricts the water diffusion and decreases the value of ADC within tumors, which makes them appear hypointense on ADC maps. The role of this sequence now largely exceeds its first clinical apparitions in neuroimaging, whereby the method helped diagnose the early phases of cerebral ischemic stroke. The applications extend to whole-body imaging for both neoplastic and non-neoplastic diseases. This review emphasizes the integration of DWI in the genitourinary system imaging by outlining the sequence's usage in female pelvis, prostate, bladder, penis, testis and kidney MRI. In gynecologic imaging, DWI is an essential sequence for the characterization of cervix tumors and endometrial carcinomas, as well as to differentiate between leiomyosarcoma and benign leiomyoma of the uterus. In ovarian epithelial neoplasms, DWI provides key information for the characterization of solid components in heterogeneous complex ovarian masses. In prostate imaging, DWI became an essential part of multi-parametric Magnetic Resonance Imaging (mpMRI) to detect prostate cancer. The Prostate Imaging-Reporting and Data System (PI-RADS) scoring the probability of significant prostate tumors has significantly contributed to this success. Its contribution has established mpMRI as a mandatory examination for the planning of prostate biopsies and radical prostatectomy. Following a similar approach, DWI was included in multiparametric protocols for the bladder and the testis. In renal imaging, DWI is not able to robustly differentiate between malignant and benign renal tumors but may be helpful to characterize tumor subtypes, including clear-cell and non-clear-cell renal carcinomas or low-fat angiomyolipomas. One of the most promising developments of renal DWI is the estimation of renal fibrosis in chronic kidney disease (CKD) patients. In conclusion, DWI constitutes a major advancement in genitourinary imaging with a central role in decision algorithms in the female pelvis and prostate cancer, now allowing promising applications in renal imaging or in the bladder and testicular mpMRI.

Pelvic splenosis mimicking a suspicious adnexal mass.

A 58-year-old asymptomatic woman was referred to our gynecologic oncology unit for the management of a left adnexal mass found during a routine gynecologic examination. Her personal history included an emergency splenectomy at the age of 4 years old, following traumatic splenic laceration after a car accident. The patient's work-up (including transvaginal ultrasound and MRI) confirmed a pelvic solid mass, which was reported as suspicious for malignancy and classified as Ovarian-Adnexal Reporting & Data System-MRI 5. An exploratory laparoscopy was performed, showing a reddish blue lesion located at the left broad ligament. Histologic analysis showed the presence of splenic tissue and normal adnexa. The postoperative follow-up was uneventful.Pelvic splenosis is a challenging diagnosis rarely made preoperatively due to concern for malignancy. In the presence of a pelvic mass, the collection of a detailed patient's history, including information about previous splenic rupture, might raise suspicion for pelvic splenosis.