Transplant renal artery stenosis: utilization of machine learning to identify ancillary sonographic and doppler parameters to predict stenosis in patients with graft dysfunction.

PURPOSE: To determine if ancillary sonographic and Doppler parameters can be used to predict transplant renal artery stenosis in patients with renal graft dysfunction. MATERIALS AND METHODS: IRB-approved, HIPAA-compliant retrospective study included 80 renal transplant patients who had renal US followed by renal angiogram between January 2018 and December 2019. A consensus read of two radiologists recorded these parameters: peak systolic velocity, persistence of elevated velocity, grayscale narrowing, parvus tardus, delayed systolic upstroke, angle of the systolic peak (SP angle), and aliasing. Univariate analysis using t-test or chi-square was performed to determine differences between patients with and without stenosis. P values under 0.05 were deemed statistically significant. We used machine learning algorithms to determine parameters that could better predict the presence of stenosis. The algorithms included logistic regression, random forest, imbalanced random forest, boosting, and CART. All 80 cases were split between training and testing using stratified sampling using a 75:25 split. RESULTS: We found a statistically significant difference in grayscale narrowing (p = 0.0010), delayed systolic upstroke (p = 0.0002), SP angle (p = 0.0005), and aliasing (p = 0.0024) between the two groups. No significant difference was found for an elevated peak systolic velocity (p = 0.1684). The imbalanced random forest (IRF) model was selected for improved accuracy, sensitivity, and specificity. Specificity, sensitivity, AUC, and normalized Brier score for the IRF model using all parameters were 73%, 81%, 0.82, and 69 in the training set, and 78%, 58%, 0.78, and 80 in the testing set. VIMP assessment showed that the combination of variables that resulted in the most significant change of the training set performance was that of grayscale narrowing and SP angle. CONCLUSION: Elevated peak systolic velocity did not discriminate between patients with and without TRAS. Adding ancillary parameters into the machine learning algorithm improved specificity and sensitivity similarly in the training and testing sets. The algorithm identified the combination of lumen narrowing coupled with the angle of the systolic peak as better predictor of TRAS. This model may improve the accuracy of ultrasound for transplant renal artery stenosis.

Endometrial cancer from early to advanced-stage disease: an update for radiologists.

The purpose of this article is to review the current molecular classification of endometrial cancer, the imaging findings in early and advanced disease, and the current management strategies, focusing on the new systemic therapies for advanced EC. In recent years, the management of endometrial cancer has significantly changed. The molecular characterization of endometrial cancer has shed new light into the biologic behavior of this disease, the International Federation of Gynecology and Obstetrics staging system was recently revised, and imaging was formally incorporated in the management of endometrial cancer. Recent genomic analysis of endometrial cancer led to the approval of new molecular-targeted therapies and immune checkpoint inhibitors. Imaging allows assessment of myometrial invasion, cervical stromal extension, lymph node involvement and distant metastases, and has a crucial role for treatment planning. Treatment strategies, which include surgery, radiation and systemic therapies are based on accurate staging and risk stratification.

The "Speckle Sign" in the Diagnosis of Posterior Compartment Endometriosis.

OBJECTIVE: To determine usefulness of the "speckle sign" in the diagnosis of deep invasive endometriosis. MATERIALS AND METHODS: This HIPAA-compliant, institutional review board-approved retrospective study with informed consent waived included 25 women (mean age 20-69 years) with histopathologically confirmed posterior cul-de-sac endometriosis between 2013 and 2018. Transvaginal ultrasound exams of these patients were reviewed by 2 expert radiologists searching for the "speckle sign," defined as irregular obliteration of the posterior cul-de-sac and bright (hyperechoic) internal echoes. The frequency of additional findings such as "kissing ovaries," endometriomas in the adnexa, bowel tethering in the posterior pelvic compartment, retroflexed uterus, adenomyosis, and pelvic free fluid were also analyzed. Data regarding clinical features, histopathologic findings and management were collected through a review of the medical record. RESULTS: Reader one identified posterior compartment endometriosis in 20/25 patients, and reader two in 22/25 patients, with 96% agreement. Adnexal endometriomas were found in 21/25 patients for both readers (k = 0.70) and were bilateral in 23% of patients. The ovaries were adherent to each other in the midline ("kissing ovaries") in 50% of patients; the bowel was tethered anteriorly in 20%; the presence of adenomyosis was seen in about 27%, and a retroflexed uterus was seen in 24% of patients. CONCLUSIONS: The speckle sign could be helpful in making the diagnosis of posterior compartment endometriosis, and the sign is often found in conjunction with other imaging features of endometriosis.

Characterizing T2 iso- and hypo-intense renal masses on MRI: Can templated algorithms improve accuracy?

PURPOSE: To assess if a templated algorithm can improve the diagnostic performance of MRI for characterization of T2 isointense and hypointense renal masses. METHODS: In this retrospective study, 60 renal masses with histopathologic diagnoses that were also confirmed as T2 iso- or hypointense on MRI were identified (mean ± standard deviation, range: 3.9 ± 2.5, 1.0-13.7 cm). Two semi-quantitative diagnostic algorithms were created based on MRI features of renal masses reported in the literature. Three body-MRI trained radiologists provided clinical diagnoses based on their experience and separately provided semiquantitative data for each components of the two algorithms. The algorithms were applied separately by a radiology trainee without additional interpretive input. Logistic regression was used to compare the accuracy of the three methods in distinguishing malignant versus benign lesions and in diagnosing the exact histopathology. Inter-reader agreement for each method was calculated using Fleiss' kappa statistics. RESULTS: The accuracy of the two algorithms and clinical experience were similar (70%, 69%, and 64%, respectively, p = 0.22-0.32), with fair to moderate inter-reader agreement (Fleiss's kappa: r = 0.375, r = 0.308, r = 0.375, respectively, all p < 0.0001). The accuracy of the two algorithms and clinical experience in diagnosing specific histopathology were also no different from each other (34%, 29%, and 32%, respectively, p = 0.49-0.74), with fair to moderate inter-reader agreement (Fleiss's kappa: r = 0.20, r = 0.28, r = 0.375, respectively, all p < 0.0001). CONCLUSION: Semi-quantitative templated algorithms based on MRI features of renal masses did not improve the ability to diagnose T2 iso- and hypointense renal masses when compared to unassisted interpretation by body MR trained subspecialists.

Multimodality imaging and clinicopathologic assessment of abdominal wall endometriosis: knocking down the enigma.

PURPOSE: To review the clinical, multimodality imaging, and pathologic characteristics of abdominal wall endometriosis (AWE), the most common type of extra-pelvic endometriosis. METHODS: 116 women with histopathologically confirmed extragenital endometriosis diagnosed between 2/2014 and 6/2017 were evaluated retrospectively. Of these, 26 (22.4%) were found to have AWE and 18/26 met inclusion criteria for imaging. Available imaging studies were re-reviewed by two expert radiologists. Data regarding clinical features, histopathologic findings, and management were collected through medical record review. RESULTS: 21 pathology-proven AWE deposits were identified by imaging in 18 women [mean age at diagnosis of 38.5 years (range 31-48)]. Prior C-section was present in 15/18 (83.3%) and pelvic endometriosis in 3/18 (16.7%) patients. Patients presented with abdominal pain in 14/18 (77.8%) cases, which was cyclical in 8/14; palpable mass in 12/18 (66.7%); fluid discharge in 2/18 (11.1%); and local skin discoloration in 2/18 (11.1%). Of the 21 lesions, 15 were evaluated with US, 10 with CT, and 5 with MRI. Mean lesion dimensions were 2.5 × 2.2 × 2.6 cm, and deposits were predominantly located at midline or left hemiabdomen [22/30 (73.3%)], were either stellate [15/30 (50%)] or round [15/30 (50%)] in shape, had ill-defined margins [21/30 (70%)], were heterogenous in appearance [27/30 (90%)], and involved both deep and superficial abdominal wall layers [17/30 (56.7%)]. On US, lesions were mainly isoechoic/hyperechoic [7/15 (46.7%)], and scarcely vascular [8/15 (53.3%)] with a peripheral vascular pattern [8/13 (61.5%)]. On CT, AWEs were hypervascular and homogeneous [8/10 (80%)], superiorly located to scar tissue, and on MRI lesions appeared hyperintense [4/5 (80%)] to muscle with T2 cystic and T1 hemorrhagic foci [4/5 (80%)]. In 23/27 (85.1%) original reports, there was at least one known mass prior to imaging; AWE was correctly diagnosed in only 7/23 (30.4%) cases. In those with no prior knowledge of a mass, the lesion was detected in 3/4 (75%), but AWE was only diagnosed in a single case. Median time between onset of symptoms and histopathology was 24.41 moths (IQR 15.18-47.33). CONCLUSIONS: AWE is a challenging clinical entity frequently diagnosed with a significant delay and easily misinterpreted despite multimodality imaging. Familiarity with its radiologic features holds the potential for positively impacting diagnosis.

MRI of cervical cancer with a surgical perspective: staging, prognostic implications and pitfalls.

LEARNING OBJECTIVES: Magnetic resonance imaging (MRI) of the pelvis is the most reliable imaging modality for staging, treatment planning, and follow-up of cervical cancer; and its findings may now be incorporated into the International Federation of Gynecology and Obstetrics Federation (FIGO) 2018 clinical staging of cervical cancer. It is imperative that radiologists are familiar with the imaging appearance of the different stages of cervical cancer as well as the post-treatment changes and imaging pitfalls given the respective clinical manifestations, treatment regimens, and prognosis of an accurate diagnosis. In addition to the different stages of cervical cancer, we address the imaging techniques for diagnosis, staging and treatment implications as well as the changes of the new FIGO staging system. BACKGROUND: The use of MRI to diagnose and stage cervical cancer is steadily increasing and the new FIGO stagi ng system, previously based on clinical examination, now allows the staging or change of staging based on the imaging findings. MRI can evaluate the extent of disease because of its excellent contrast resolution for pelvic tissues and organs, high accuracy and detailed elaboration of the cervical/uterovaginal anatomy. CONTENT: Relevant anatomy, including normal MRI appearance of the cervix, parametria and pelvic ligaments; different stages of cervical cancer on MRI with prognostic and therapeutic implications; MRI sequences, other imaging modalities used in the staging and follow-up, treatment of different stages and the appearance of the cervix and cervical cancer post-treatment. Since clinical implications and therapeutic strategies for cervical cancer treatment vary tremendously according to degree of tumor extension, familiarity with relevant MRI techniques and findings is essential for radiologists. It is important that radiologists interpreting pelvic MRI are aware with the different stages of cervical cancer to provide useful information regarding treatment and prognosis. Pitfalls regarding the interpretation of tumor extension can interfere with an accurate diagnosis and have significant therapeutic implications.

Magnetic Resonance Imaging Features of Endometrial Polyps: Frequency of Occurrence and Interobserver Reliability.

OBJECTIVE: This study aimed to evaluate magnetic resonance imaging (MRI) features and interobserver agreement of endometrial polyps. METHODS: After institutional review board approval, our database was searched for women older than 18 years who underwent MRI pelvis and pelvic surgical intervention from 2012 to 2016. Seventy-two patients with polyps and 75 controls composed the study cohort. Two radiologists evaluated the MRIs retrospectively for polyps. Polyp characteristics and enhancement were assessed. RESULTS: Sensitivity and specificity of readers 1 and 2 were 59.7% and 88.0%, and 44.4 and 96.0%, respectively. There was moderate agreement for presence of polyps (κ = 0.556, P ≤ 0001), T2 fibrous core, and intratumoral cysts, with slight agreement for T2 signal and enhancement. Polyp size moderately correlated with pathology (κ = 0.465 [P = 0.025] for reader 1, κ = 0.562 [P = 0.029] for reader 2). The most common enhancement was same as myometrium. CONCLUSION: Magnetic resonance imaging is moderately sensitive for detecting endometrial polyps, demonstrating features that are not sensitive but can be specific, with moderate interobserver agreement.

Diagnosis of gastrogastric fistula on computed tomography: a quantitative approach.

OBJECTIVE: To determine if the attenuation of contrast material in the excluded stomach compared with the gastric pouch is helpful in diagnosing gastrogastric (GG) fistula. MATERIALS AND METHODS: In a retrospective study, 13 CT scans in 12 patients (age 43.2 ± 9.2, 10 females) who had undergone Roux-en-Y gastric bypass and who had oral contrast in both the gastric pouch and excluded stomach were qualitatively and quantitatively evaluated for GG fistula by two radiologists, using upper GI series (UGI) as the gold standard. Quantitative analysis was performed by computing the relative attenuation (RA) ratio (HU in excluded stomach/HU in gastric pouch). Statistical analysis was performed to determine if the RA ratio values correlated with the UGI findings of GG fistula. RESULTS: 46.2% (6/13) of UGI studies demonstrated a GG fistula. Statistical analysis demonstrated a significant difference in RA ratio (P < 0.05) between the fistula group (1.12 ± 0.29) and the reflux group (0.56 ± 0.19). A receiver operating characteristic analysis identified an RA ratio of 0.8 that maximized sensitivity (100%), at the expense of specificity (78.6%), for diagnosing GG fistula. In contrast, the initial qualitative evaluation for GG fistula yielded a lower sensitivity (45.8%) and a higher specificity (89.2%). After taking RA ratios into account, radiologists' final conclusions achieved higher sensitivity (58.3%) and specificity (100%). CONCLUSION: The relative attenuation ratio of oral contrast in the excluded stomach versus the gastric pouch can be a reliable tool in differentiating GG fistula from oral contrast reflux up the biliopancreatic limb on CT.

Sonovaginography: A Useful Technique in the Assessment of the Lower Genital Tract.

Conventional sonographic evaluation of the cervix and vagina is compromised by inattention, poor subject contrast, and obscuring artifacts. We describe a technique involving distention of the vaginal canal and fornices with ultrasound gel, providing an acoustic window for improved definition of the cervix and vagina. This exam is usually performed in concert with transvaginal sonography, but a transabdominal or transperineal approach may be more useful in selected scenarios. A wide variety of formerly sonographically inconspicuous conditions are demonstrable with this technique, many of which were undetected or inadequately characterized on the physical exam. Cervical polyps were the most commonly seen abnormality.

Magnetic Resonance Imaging and Sonography in the Diagnosis of Placental Invasion.

OBJECTIVES: To compare older and newer magnetic resonance imaging (MRI) criteria for placental invasion and to compare the sensitivity, specificity, and accuracy of MRI and sonography in determining the depth of placental invasion. METHODS: Forty pregnant patients at high risk for morbidly adherent placenta based on prenatal sonography underwent MRI evaluations. Two reviewers, who were blinded to the original MRI and sonographic interpretations, clinical history, and obstetric/pathologic findings, reviewed the MRI examinations. The MRI and sonographic scans were analyzed for the presence and depth of invasion. The MRI scans were tabulated for the presence of dark intraplacental T2 bands, bulging of the myometrium, increased vascularity, and indistinct myometrium, loss of the dark T2 myometrial/placental interface, and a thin myometrium. The obstetric/pathologic results served as the reference standards. RESULTS: Eighteen of 40 patients had a morbidly invasive placenta. The sensitivity, specificity, and accuracy of MRI and sonography were not significantly different. The accuracy rates for determining the depth of placental invasion by readers 1 and 2 were 0.65 and 0.55, respectively (P > .05). According to the Cohen κ statistic, there was a good inter-reader agreement between the MRI readers in assessing the depth of placental invasion (κ = 0.45). The features most commonly seen were dark T2 bands, bulging of the uterus, and loss of the dark T2 interface, which were all associated with the presence of placental invasion. CONCLUSIONS: The diagnosis of placental invasion remains challenging on sonography and MRI, which perform similarly. The presence of 2 or more criteria adds specificity to the diagnosis of placental invasion on MRI.

Epidemiology of needlesticks and other sharps injuries and injection safety practices in the Dominican Republic.

BACKGROUND: Contaminated sharps, such as needles, lancets, scalpels, broken glass, specimen tubes, and other instruments, can transmit bloodborne pathogens such as HIV, hepatitis B (HBV), and hepatitis C viruses (HCV). METHODS: Observation of facilities and injections and questionnaire-guided interviews were conducted in 2005 among health care workers (HCWs) in 2 public hospitals in Santo Domingo and 136 public immunization clinics (IC) in the Dominican Republic. Injection practices and sharps injuries (SIs) in health care facilities in the Dominican Republic were assessed in cross-sectional surveys to identify areas in which preventive efforts might be directed to make injection practices safer. RESULTS: Of the 304 hospital HCWs and 136 ICs HCWs interviewed, 98 (22.3%) reported > or =1 SIs during the previous 12 months. ICs had a lower incidence (13 per 100 per person-years [p-y]) of SIs than hospitals (65 per 100 p-y) (P < .0001). Unsafe needle recapping was observed in 98% of all injections observed at hospitals but in only 12% of injections at ICs (P < .0001). Sharps were observed improperly disposed in regular waste containers in 24 (92%) of 26 areas at which injections are prepared at the hospitals but in only 11 (8%) of 136 ICs (P < .0001). Training in injection safety was received by 4% of HCWs in hospitals but by 77% in ICs (P < .001). Of 425 HCWs, 247 (58%) were fully immunized against hepatitis B. There was a higher risk of SIs among staff dentists (adjusted relative risks [aRR], 5.9; 95% confidence interval [CI]: 2.8-12.6), resident physicians (aRR, 3.5; 95% CI: 1.8-6.9), and those who gave > or =11 therapeutic injections per day (aRR, 1.6; 95% CI: 1.1-2.4). CONCLUSION: Injection practices at ICs were safer than those found at public hospitals. Preventive strategies to lower SIs in public hospitals should include regular training of hospital staff to minimize needle recapping and improper disposal, among other interventions to reduce the dangers of needles.