Retained products of conception (RPOC) are a common and treatable complication after delivery or termination of pregnancy. The pathologic diagnosis of RPOC is made based on the presence of chorionic ...villi, which indicates persistent placental or trophoblastic tissue. In the setting of postpartum hemorrhage, however, distinguishing RPOC from bleeding related to normal postpartum lochia or uterine atony can be clinically challenging. Ultrasonographic (US) evaluation can be particularly helpful in these patients, and a thickened endometrial echo complex (EEC) or a discrete mass in the uterine cavity is a helpful gray-scale US finding that suggests RPOC. However, gray-scale US findings alone are inadequate for accurate diagnosis. Detection of vascularity in a thickened EEC or an endometrial mass at color or power Doppler US increases the positive predictive value for the diagnosis of RPOC. Computed tomography or magnetic resonance imaging may be helpful when US findings are equivocal and typically demonstrates an enhancing intracavitary mass in patients with RPOC. Diagnostic pitfalls are rare but may include highly vascular RPOC, which can be mistaken for a uterine arteriovenous malformation; true arteriovenous malformations of the uterus; invasive moles; blood clot; and subinvolution of the placental implantation site.
CT and MRI are the imaging modalities of choice to guide the clinical management of incidentally discovered pancreatic cysts. Most of these lesions are mucinous cysts with varying degrees of ...malignant potential. This article reviews the CT and MRI findings that help differentiate a potentially aggressive lesion that requires EUS or surgery from a lesion of low malignant potential that is appropriate for imaging surveillance. The imaging-based societal guidelines for these cysts are reviewed.
Purpose
To evaluate angle-corrected peak systolic cystic artery velocity (CAv) as a predictor of acute cholecystitis among patients presenting to the emergency department (ED) with right upper ...quadrant (RUQ) pain.
Methods
In this IRB-approved and retrospective study, CAv was evaluated in 73 patients, 43 who underwent definitive treatment with cholecystectomy or percutaneous cholecystostomy and 30 control patients without clinical suspicion for cholecystitis. In addition to CAv, the following were reviewed by 3 radiologists: CBD diameter, cholelithiasis, impacted stone in the neck, sludge, gallbladder wall thickness > 3 mm, gallbladder transverse dimension ≥ 4 cm, longitudinal dimension ≥ 8 cm, tensile gallbladder fundus sign, pericholecystic fluid, pericholecystic echogenic fat, and sonographic Murphy sign.
Results
Of the 43 patients who underwent definitive treatment, 25 had acute cholecystitis (34%) and 18 (25%) had chronic cholecystitis. Average CAv measurements were 50 ± 16 cm/s (acute), 28 ± 8 cm/s (chronic), and 22 ± 8 cm/s (control;
p
< 0.0001). In univariate analysis, among patients who underwent definitive therapy, CAv ≥ 40 cm/s, gallbladder wall thickness, stone impaction, GB long dimension ≥ 8 cm, and elevated WBC were associated with acute cholecystitis (
p
< 0.05). In multivariate analysis, CAv ≥ 40 cm/s was the only statistically significant variable (
p
= 0.016). CAv ≥ 40 cm/s alone had a PPV of 94.7% and overall accuracy of 81.4% in diagnosing acute cholecystitis.
Conclusion
CAv ≥ 40 cm/s is highly associated with acute cholecystitis in patients presenting to the ED with RUQ pain.
Purpose
To assess the performance of a machine learning model trained with contrast-enhanced CT-based radiomics features in distinguishing benign from malignant solid renal masses and to compare ...model performance with three abdominal radiologists.
Methods
Patients who underwent intra-operative ultrasound during a partial nephrectomy were identified within our institutional database, and those who had pre-operative contrast-enhanced CT examinations were selected. The renal masses were segmented from the CT images and radiomics features were derived from the segmentations. The pathology of each mass was identified; masses were labeled as either benign oncocytoma or angiomyolipoma (AML) or malignant clear cell, papillary, or chromophobe renal cell carcinoma (RCC) depending on the pathology. The data were parsed into a 70/30 train/test split and a random forest machine learning model was developed to distinguish benign from malignant lesions. Three radiologists assessed the cohort of masses and labeled cases as benign or malignant.
Results
148 masses were identified from the cohort, including 50 benign lesions (23 AMLs, 27 oncocytomas) and 98 malignant lesions (23 clear cell RCC, 44 papillary RCC, and 31 chromophobe RCCs). The machine learning algorithm yielded an overall accuracy of 0.82 for distinguishing benign from malignant lesions, with an area under the receiver operating curve of 0.80. In comparison, the three radiologists had significantly lower accuracies (
p
= 0.02) ranging from 0.67 to 0.75.
Conclusion
A machine learning model trained with CT-based radiomics features can provide superior accuracy for distinguishing benign from malignant solid renal masses compared to abdominal radiologists.
Background
Studies to identify preoperative prognostic variables for pancreatic neuroendocrine tumor (PNET) have been inconclusive. Specifically, the prevalence and prognostic significance of ...radiographic calcifications in these tumors remains unclear.
Methods
From 1998 to 2009, a total of 110 patients with well-differentiated PNET underwent surgical resection at our institution. Synchronous liver metastases present in 31 patients (28%) were addressed surgically with curative intent. Patients with high-grade PNET were excluded. The presence of calcifications in the primary tumor on preoperative computed tomography was recorded and correlated with clinicopathologic variables and overall survival.
Results
Calcifications were present in 16% of patients and were more common in gastrinomas and glucagonomas (50%), but never encountered in insulinomas. Calcified tumors were larger (median size 4.5 vs. 2.3 cm,
P
= 0.04) and more commonly associated with lymph node metastasis (75 vs. 35%,
P
= 0.01), synchronous liver metastasis (62 vs. 21%,
P
< 0.01), and intermediate tumor grade (80 vs. 31%,
P
< 0.01). On multivariate analysis of factors available preoperatively, calcifications (
P
= 0.01) and size (
P
< 0.01) remained independent predictors of lymph node metastasis. Overall survival after resection was significantly worse in the presence of synchronous liver metastasis (5-year, 64 vs. 86%,
P
= 0.04), but not in the presence of radiographic calcifications.
Conclusions
Calcifications on preoperative computed tomography correlate with intermediate grade and lymph node metastasis in well-differentiated PNET. This information is available preoperatively and supports the routine dissection of regional lymph nodes through formal pancreatectomy rather than enucleation in calcified PNET.
The objective of our study was to determine the negative predictive value of MDCT with curved planar reformations for detecting vascular invasion and predicting overall resectability in patients with ...pancreatic adenocarcinoma.
Imaging findings related to vascular invasion and overall tumor resectability in 25 patients who underwent contrast-enhanced biphasic MDCT evaluation were correlated with actual vessel invasion and overall resectability determined at surgery and pathologic examination. The presence of vascular invasion was assessed in 110 major peripancreatic vessels in 22 patients who underwent resection.
On MDCT, 23 (92%) of 25 patients were deemed to have resectable pancreatic adenocarcinoma. The tumors in the remaining two (8%) were considered not resectable because of the presence of vascular invasion (which was confirmed in only one patient at surgery). Of those 23 patients deemed to be candidates for curative resection on the basis of MDCT results, 20 were found to have resectable adenocarcinoma at time of surgery, yielding a negative predictive value for MDCT of 87% (20/23 patients) for overall resectability. In the other three patients, adenocarcinoma was deemed to be unresectable because of small metastases to the liver (two patients) or to the peritoneum (one patient) discovered at surgery. For detection of vascular invasion, MDCT yielded a negative predictive value of 100% (108/108 vessels) with no false-negative findings and an accuracy of 99% (109/110 vessels) with 108 true-negative findings, one true-positive finding, and one false-positive finding.
Our preliminary data on MDCT show that the technique has excellent negative predictive value for vascular invasion and good negative predictive value for overall tumor resectability in patients with pancreatic adenocarcinoma, suggesting an improvement over previous results reported using single-detector CT. The problem of undetected micrometastases to the liver and peritoneum remains.
Stem/progenitor cells from bone marrow and other sources have been shown to repair injured tissues by differentiating into tissue-specific phenotypes, by secreting chemokines, and, in part, by cell ...fusion. Here we prepared the stem/progenitor cells from human bone marrow (MSCs) and implanted them into the dentate gyrus of the hippocampus of immunodeficient mice. The implanted human MSCs markedly increased the proliferation of endogenous neural stem cells that expressed the stem cell marker Sox2. Labeling of the mice with BrdUrd demonstrated that, 7 days after implantation of the human MSCs, BrdUrd-labeled endogenous cells migrated throughout the dorsal hippocampus (positive for doublecortin) and expressed markers for astrocytes and for neural or oligodendrocyte progenitors. Subpopulations of BrdUrd-labeled cells exhibited short cytoplasmic processes immunoreactive for nerve growth factor and VEGF. By 30 days after implantation, the newly generated cells expressed markers for more mature neurons and astrocytes. Also, subpopulations of BrdUrd-labeled cells exhibited elaborate processes immunoreactive for ciliary neurotrophic factor, neurotrophin-4/5, nerve growth factor, or VEGF. Therefore, implantation of human MSCs stimulated proliferation, migration, and differentiation of the endogenous neural stem cells that survived as differentiated neural cells. The results provide a paradigm to explain recent observations in which MSCs or related stem/progenitor cells were found to produce improvements in disease models even though a limited number of the cells engrafted.
Groove or paraduodenal pancreatitis is an uncommon fibroinflammatory form of pancreatitis involving the anatomic space of the pancreatic groove located between the C-loop of the duodenum and the head ...of the pancreas. Although in some patients there are distinctive clinical and imaging features of groove pancreatitis (GP), there is often significant overlap with other infiltrative processes involving the pancreatic groove such as pancreatic ductal adenocarcinoma or duodenal carcinoma. In this review, we summarize the most distinctive clinical and imaging aspects of GP and highlight some important distinguishing features that may aid in differentiating malignant lesions involving the pancreatic groove.
The objective of this study was to test the hypothesis that thickening of the lamina propria, a finding produced by lymphoid hyperplasia, is significantly associated with false-positive sonographic ...diagnoses of appendicitis in 6- to 8-mm noncompressible appendixes.
Sonograms of 119 consecutive patients with suspected appendicitis and 6- to 8-mm noncompressible appendixes were retrospectively blindly evaluated for thickening of the lamina propria (short axis thickness ≥ 1 mm). The reference standard for appendicitis was pathologic analysis of resected specimens. Results were compared with the two-tailed Fisher exact test.
Thirty-one patients (26.1%) had a thickened lamina propria and 88 (73.9%) did not. Of the 27 pediatric patients with a thickened lamina propria, five (18.5%) had true-positive and 22 (81.5%) had false-positive sonograms for appendicitis; among the 55 pediatric patients without a thickened lamina propria, 27 (49.1%) had true-positive and 28 (50.9%) had false-positive sonograms for appendicitis (p = 0.009). Similar differences in adult patients were not statistically significant. All five pediatric patients with appendicitis and thickened lamina propria also showed two or more findings of periappendiceal fluid, hyperechoic periappendiceal fat, or mural hyperemia on color Doppler examination, compared with two of 22 similar pediatric patients without appendicitis (p < 0.001).
Lymphoid hyperplasia may result in a noncompressible appendix 6-8 mm in diameter and may be misdiagnosed as appendicitis in pediatric patients. True-positive diagnoses of appendicitis can be accurately identified by the presence of at least two additional findings from the group of periappendiceal fluid, hyperechoic periappendiceal fat, and mural hyperemia. Identifying the characteristic sonographic appearance of lymphoid hyperplasia may help prevent false-positive misdiagnoses of appendicitis.
The purpose of this American Urological Association (AUA)/Society of Urologic Oncology (SUO) guideline amendment is to provide a useful reference on the effective evidence-based treatment strategies ...for non-muscle invasive bladder cancer (NMIBC).
In 2023, the NMIBC guideline was updated through the AUA amendment process in which newly published literature is reviewed and integrated into previously published guidelines in an effort to maintain currency. The amendment allowed for the incorporation of additional literature released since the previous 2020 amendment. The updated search gathered literature from July 2019 to May 2023. This review identified 1918 abstracts, of which 75 met inclusion criteria.When sufficient evidence existed, the body of evidence was assigned a strength rating of A (high), B (moderate), or C (low) in support of Strong, Moderate, or Conditional Recommendations. In the absence of sufficient evidence, additional information is provided as Clinical Principles and Expert Opinions.
Updates were made to statements on variant histologies, urine markers after diagnosis of bladder cancer, intravesical therapy, BCG maintenance, enhanced cystoscopy, and future directions. Further revisions were made to the methodology and reference sections as appropriate.
This guideline seeks to improve clinicians' ability to evaluate and treat patients with NMIBC based on currently available evidence. Future studies will be essential to further support or refine these statements to improve patient care.
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