Quantitative evaluation of Saliency-Based Explainable artificial intelligence (XAI) methods in Deep Learning-Based mammogram analysis.

BACKGROUND: Explainable Artificial Intelligence (XAI) is prominent in the diagnostics of opaque deep learning (DL) models, especially in medical imaging. Saliency methods are commonly used, yet there's a lack of quantitative evidence regarding their performance. OBJECTIVES: To quantitatively evaluate the performance of widely utilized saliency XAI methods in the task of breast cancer detection on mammograms. METHODS: Three radiologists drew ground-truth boxes on a balanced mammogram dataset of women (n = 1496 cancer-positive and negative scans) from three centers. A modified, pre-trained DL model was employed for breast cancer detection, using MLO and CC images. Saliency XAI methods, including Gradient-weighted Class Activation Mapping (Grad-CAM), Grad-CAM++, and Eigen-CAM, were evaluated. We utilized the Pointing Game to assess these methods, determining if the maximum value of a saliency map aligned with the bounding boxes, representing the ratio of correctly identified lesions among all cancer patients, with a value ranging from 0 to 1. RESULTS: The development sample included 2,244 women (75%), with the remaining 748 women (25%) in the testing set for unbiased XAI evaluation. The model's recall, precision, accuracy, and F1-Score in identifying cancer in the testing set were 69%, 88%, 80%, and 0.77, respectively. The Pointing Game Scores for Grad-CAM, Grad-CAM++, and Eigen-CAM were 0.41, 0.30, and 0.35 in women with cancer and marginally increased to 0.41, 0.31, and 0.36 when considering only true-positive samples. CONCLUSIONS: While saliency-based methods provide some degree of explainability, they frequently fall short in delineating how DL models arrive at decisions in a considerable number of instances.

A joint convolutional-recurrent neural network with an attention mechanism for detecting intracranial hemorrhage on noncontrast head CT.

To investigate the performance of a joint convolutional neural networks-recurrent neural networks (CNN-RNN) using an attention mechanism in identifying and classifying intracranial hemorrhage (ICH) on a large multi-center dataset; to test its performance in a prospective independent sample consisting of consecutive real-world patients. All consecutive patients who underwent emergency non-contrast-enhanced head CT in five different centers were retrospectively gathered. Five neuroradiologists created the ground-truth labels. The development dataset was divided into the training and validation set. After the development phase, we integrated the deep learning model into an independent center's PACS environment for over six months for assessing the performance in a real clinical setting. Three radiologists created the ground-truth labels of the testing set with a majority voting. A total of 55,179 head CT scans of 48,070 patients, 28,253 men (58.77%), with a mean age of 53.84 ± 17.64 years (range 18-89) were enrolled in the study. The validation sample comprised 5211 head CT scans, with 991 being annotated as ICH-positive. The model's binary accuracy, sensitivity, and specificity on the validation set were 99.41%, 99.70%, and 98.91, respectively. During the prospective implementation, the model yielded an accuracy of 96.02% on 452 head CT scans with an average prediction time of 45 ± 8 s. The joint CNN-RNN model with an attention mechanism yielded excellent diagnostic accuracy in assessing ICH and its subtypes on a large-scale sample. The model was seamlessly integrated into the radiology workflow. Though slightly decreased performance, it provided decisions on the sample of consecutive real-world patients within a minute.

Shear wave elastography findings in Immunoglobulin A Nephropathy patients: is it more specific and sensitive for interstitial fibrosis or interstitial fibrosis/tubular atrophy?

Background: Prediction of prognosis in Immunoglobulin A Nephropathy (IgAN) and taking appropriate precautions may reduce annual incidence of chronic kidney disease. This may be possible by close follow-up for the development and progression of interstitial fibrosis (IF) or interstitial fibrosis/tubular atrophy (IFTA) in IgAN patients.Aim: To investigate whether Young's elastic modulus (YM) which measured shear wave elastography (SWE) might be used for follow-up of IF or IFTA in IgAN patients.Methods: Prospective study was approved by Human Research Ethics Committee. Group 1 consisted of patients with IgAN. Group 2 consisted of healthy control participants. Young's elastic modulus which is a value of stiffness along with longitudinal stiffness was used to evaluate tissue elasticity. Specificity, sensitivity, positive predictive value (PPV) of YM for the presence of IF and IFTA were evaluated.Results: Group 1 consisted of 30 participants, and group 2 consisted of 32 participants. Sensitivity and specificity of SWE to diagnose presence of IF for YM > 15 kPa were 89% and 90%, respectively. PPV among the ones whom IF was diagnosed by YM >15 kPa was 91%. Sensitivity and specificity of SWE to diagnose presence of IFTA for YM > 15 were 65% and 51%, respectively. PPV among the ones whom IFTA was diagnosed by YM >15 kPa was 78.1%.Conclusions: YM which measured SWE is highly specific and sensitive in the diagnosis of IF, but not for IFTA in IgAN patients. Therefore, progression for IF in IgAN may be followed by SWE.

Effect of αlipoic acid and silymarin on bladder outlet obstruction.

The aim of the present study was to determine whether the treatment of obstructed rat bladders with αlipoic acid (ALA) and silymarin reverses the biochemical and physiological responses to bladder outlet obstruction (BOO). A total of 32 adult Sprague Dawley rats were divided into four groups (n=8 per group): sham (placebo surgery) animals with no treatment (group 1); control animals with surgically induced BOO (group 2); obstructed rats treated with ALA (group 3); and obstructed rats treated with silymarin (group 4). Histological evaluation, bladder weights, collagen structure, TdT-mediated biotin nick end-labeling (TUNEL), inducible nitric oxide sentase (iNOS) mRNA levels, malondialdehyde (MDA) levels and tumor necrosis factor (TNF) levels were investigated. The ALA-treated group had similar bladder weights, collagen levels and TUNEL positivity and decreased iNOS levels compared with the control group, while the silymarin group exhibited further differences. Serum MDA and TNF-α levels were both decreased in the ALA and silymarin groups. ALA treatment reduced the increased oxidative stress and bladder inflammation caused by BOO and may contribute to the protection of bladder function.

Successful treatment of enterocutaneous fistula in a hemodialysis patient with somatostatin.

Although cysticercosis is the most common parasitic disease affecting the central nervous system, spinal cysticercosis is rare. A rare form of spinal cysticercosis involving the whole spinal canal is presented. A 45-year-old Korean male had a history of intracranial cysticercosis and showed progressive paraparesis. Spinal magnetic resonance scan showed multiple cysts compressing the spinal cord from C1 to L1. Three different levels (C1-2, T1-3, and T11-L1) required operation. Histopathological examination confirmed cysticercosis. The patient improved markedly after surgery.

Carotid artery intima-media thickness correlates with intravascular ultrasound parameters in patients with slow coronary flow.

BACKGROUND: Coronary slow flow (CSF) phenomenon is characterized by delayed opacification of coronary vessels in a normal coronary angiogram. Although clinical and pathological features have been previously described, the underlying pathophysiology has not been fully elucidated. We aimed to determine and compare the carotid intima-media thickness (CIMT) values of SCF patients and healthy subjects, and to correlate patients' values with intimal thickness and TIMI frame counts of their coronary arteries (assessed by intravascular ultrasound). METHODS: The study population consisted of 50 patients with SCF [38(76%) male, aged 53+/-7 years] and 40 normal subjects [22(55%) male, aged 51+/-8 years]. CIMT values, intravascular ultrasonographies and TIMI frame counts of the patients, and CIMT of the controls were investigated. RESULTS: Upon intravascular ultrasonography investigation, the common finding was longitudinally extended massive calcification throughout the epicardial coronary arteries in 44 (88%) of patients. Mean coronary intimal thickness was 0.52+/-0.1mm. CIMT was significantly increased in SCF patients than controls (0.84+/-0.14 vs. 0.66+/-0.13, p<0.0001). Besides, CIMT was significantly correlated with coronary intima-media thickness. TIMI frame counts were positively correlated with CIMT and coronary intimal thickness (p<0.05 and p<0.05 respectively). CONCLUSION: These results support the theory that SCF is the result of coronary atherosclerosis which is the part of systemic involvement.

Inspiratory and expiratory HRCT findings in Behçet's disease and correlation with pulmonary function tests.

PURPOSE: The purpose of our study was to describe the pulmonary parenchymal changes of Behçet's disease using high-resolution computed tomography and to correlate them with pulmonary function tests. MATERIALS AND METHODS: Thirty-four patients with Behçet's disease (18 men, 16 women), 3 of whom were symptomatic, were included as the study group. Four of 34 patients were smokers. Twenty asymptomatic volunteers (12 men, 8 women), 4 of whom were smokers, constituted the control group. The pulmonary function tests and high-resolution computed tomography were performed for both groups. RESULTS: Inspiratory high-resolution computed tomography findings were abnormal in nine patients (26.5%) of the study group. In eight patients, there were multiple abnormalities, whereas one patient had only one abnormality. Pleural thickening and irregularities, major fissure thickening, emphysematous changes, bronchiectasis, parenchymal bands, and irregular densities, and parenchymal nodules were the encountered abnormalities. Inspiratory high-resolution computed tomography scans were normal in the control group. On expiratory scans, there was statistically significant difference between study group and control group when air trapping, especially grades 3 and 4, was compared (P<0.01). Pulmonary function tests of both the study and the control groups were in normal ranges, and there was no statistically significant difference between the two groups according to pulmonary function tests (P>0.05). DISCUSSION AND CONCLUSION: High-resolution computed tomography is sensitive in the demonstration of pulmonary changes in patients with Behçet's disease. End-expiratory high-resolution computed tomography examination is very useful and necessary to show the presence of air trapping, thus the presence of small airway disease, even if the patient is asymptomatic or has normal pulmonary function tests.

Diagnostic value of renal parenchymal density difference on unenhanced helical computed tomography scan in acutely obstructing ureteral stone disease.

OBJECTIVES: To evaluate the diagnostic value of the renal parenchymal density difference, detected using unenhanced helical computed tomography, as a secondary sign of acute obstruction due to a ureteral stone. METHODS: Fifty-five patients with acute flank pain, in whom a ureteral stone was detected on the symptomatic side using unenhanced helical computed tomography, and 22 control subjects with no urinary stone disease were included in this prospective study. Computed tomography was performed, starting from the upper poles of the kidneys down to the base of the urinary bladder. The renal parenchymal density was measured in the upper, middle, and lower portions of each kidney, and a mean value was calculated. The difference between the mean values of the two kidneys was used to predict the presence of an acutely obstructing ureteral stone. RESULTS: In 49 patients with a ureteral stone (89.1%), the difference between the parenchymal densities of the obstructed and nonobstructed kidneys was 5 Hounsfield units (HU) or greater and was lower on the obstructed side. In the remaining 6 patients (10.9%), the density difference was less than 5 HU but was still lower on the obstructed side. All subjects in the control group had a density difference of less than 5 HU. A renal parenchymal density difference of 5.0 HU or greater had 89.1% sensitivity, 100% specificity, 100% positive predictive value, 85.7% negative predictive value, and 93.4% accuracy in predicting the presence of an acute obstructing ureteral stone. CONCLUSIONS: These data suggest that the renal parenchymal density difference may be a valuable secondary sign of acute obstructing ureteral stone disease.

Bronchiolitis obliterans organizing pneumonia associated with sulfasalazine in a patient with rheumatoid arthritis.

Pulmonary toxicity and blood dyscrasias are rare side effects of sulfasalazine. Pulmonary pathology is variable, the most common being eosinophilic pneumonia with peripheral eosinophilia, and interstitial inflammation with or without fibrosis. We here present the case of a 68-year-old female patient treated for 6 months with sulfasalazine for rheumatoid arthritis. On laboratory examination, eosinophil count was 97 x 10(3) mm(3). Thorocoscopic biopsy was performed. Histopathologic diagnosis was bronchiolitis obliterans organizing pneumonia (BOOP). This is the first case in the literature to present with sulfasalazine-induced BOOP in a patient with seronegative RA.

HRCT evaluation of the accessory fissures of the lung.

INTRODUCTION: The purpose of this study was to classify the accessory fissures of the lung and to assess their frequency by using high-resolution CT. METHODS AND PATIENTS: HRCT scans of 115 patients were prospectively reviewed. 1 mm thin sections were obtained at 10 mm intervals with a scan time of 1.9 s. The fissure and its relationship to the segmental bronchovascular structures were then evaluated on transverse sections. RESULTS: Forty-four accessory fissures were detected in 35 of 115 patients. The most common accessory fissure was the inferior accessory fissure (12%). The second most common accessory fissure was the left minor fissure (8%). The right superior accessory fissure (5%), the accessory fissure between the medial and lateral segments of the right middle lobe (5%), and the accessory fissure between the superior and inferior segments of the lingula (5%) were seen in equal frequencies. Also, intersegmental accessory fissures, namely the fissure between the anterobasal and laterobasal of both the right (1%) and the left (2%) lower lobes were detected. We found only one subsegmental accessory fissure. DISCUSSION AND CONCLUSION: The inferior accessory fissure and the left minor fissure were the most common accessory fissures in our study.

Two episodes of anuria and acute pulmonary edema in a losartan-treated patient with solitary kidney.

Atherosclerotic renal artery stenosis (RAS) is an increasingly important cause of end-stage kidney disease, and may cause hypertension, progressive renal failure, and recurrent pulmonary edema. Herein, we report two episodes of anuria and acute pulmonary edema associated with losartan treatment in a hypertensive patient with preexisting severe renal artery stenosis in a solitary kidney. After successful percutaneous renal balloon angioplasty procedure, urine flow was started immediately, despite 10 days of anuria. Blood pressure measurements were still at acceptable levels with a low dose Beta blocker, and serum creatinine levels were normal even after eight months. PTRA should be done in such patients, even with prolonged anuria. Physicians who recommend angiotensin receptor blockers in patients with RAS, especially in patients wih hypovolemia or a solitary kidney, should be careful about this complication.

Bone mineral density in patients with Behçet's disease.

Behçet's disease is a complex, multisystemic, inflammatory disorder characterized clinically by recurrent oral and genital ulcerations as well as uveitis, sometimes leading to blindness. The etiology and pathogenesis of this syndrome remain obscure. However, various factors are suspected, including genetic propensity, infectious precipitants, and immunological abnormalities. Considering the chronicity and unclear etiology of the disease, we conducted a prospective investigation of a possible alteration in the bone mineral density of affected persons. Thirty-five patients (18 males and 17 females, mean age 38.02+/-7.93 years) diagnosed with Behçet's disease and 33 sex- and age-matched healthy controls (14 males and 19 females, mean age 40.06+/-7.66 years) were seen on an outpatient basis, and bone densitometry measurements were done from June 2000 to December 2002 at the Mersin University Hospital in Turkey. Postmenopausal women with Behçet's disease and patients receiving oral corticosteroid therapy were excluded from the study. The mean disease duration was 6.68+/-7.05 years. Bone mineral density was measured with dual X-ray absorptiometry at the lumbar spine and right femur. The mean Z scores of the patient and control groups were -0.50+/-1.06 and -0.13+/-0.92 at the lumbar spine, respectively, and 0.38+/-1.07 and 0.45+/-1.20 at the right femur, respectively. No significant differences in bone mineral density values were detected in the groups at either the lumbar (P = 0.15) or right femur (P = 0.82) site. Body mass index and disease duration did not influence bone mineral density, and age had a positive correlation with bone mineral density in patients with Behçet's disease. In conclusion, although it is difficult to draw definite conclusions due to the relatively small sample size, our study confirms that bone mineral density in Behçet's disease was not lower than in healthy subjects.

Involvement of the proximal tibiofibular joint in osteoarthritis of the knee.

This study was performed to evaluate the possible involvement of the proximal tibiofibular joint in primary osteoarthritis of the knee. A total of 40 patients with primary osteoarthritis of the knee who had magnetic resonance imaging scans were reexamined for proximal tibiofibular joint involvement. The patient was questioned if pain was present in the proximal tibiofibular joint while at rest, when walking and climbing stairs. Symptoms were evaluated by applying moderate compression over the proximal tibiofibular joint during active ankle and knee motions. Magnetic resonance imaging scans were reexamined by two radiologists. Three of the 40 patients had minimal or moderate pain in the proximal tibiofibular joint during stair-climbing and on clinical examination. Magnetic resonance imaging scans of these three patients revealed osteophyte or subchondral cyst formation, or both. Degenerative changes in the proximal tibiofibular joint may be evident in association with osteoarthritis of the knee and may result in lateral-sided pain at the knee.

Open-mouth versus closed-mouth radiographs of the nasopharynx in the evaluation of nasopharyngeal airway obstruction.

The open-mouth and closed-mouth nasopharyngeal airway radiographs of 53 children, whose symptomatology score was concordant with nasopharyngeal airway obstruction that may be due to adenoidal enlargement, were taken and, for each radiograph, nasopharyngeal airway/soft palate (NA/SP) ratio was measured and graded using the method of Cohen and Konak. According to the statistical analysis, since closed-mouth views correlated better with the symptomatology score than the open-mouth views, if a radiological measurement is needed to evaluate the nasopharyngeal airway obstruction, closed-mouth views can be chosen.

Antrolithiasis: a retrospective study.

In this retrospective study, the computed tomography (CT) archives of paranasal sinus examinations were reviewed and three cases of antroliths are presented. The archives of paranasal sinus CT studies of 1957 patients (1023 females, 934 males, mean age 36.5 years) were surveyed. CT studies were performed using 3 mm collimation and interval in the coronal, axial or both coronal and axial planes. Three out of 1957 patients demonstrated antroliths, all in the left maxillary sinus. Associated sinusitis was detected in all three patients. Only one patient was operated. The chemical analysis of the antrolith revealed it to be a calcium oxalate stone. All the relevant literature is reviewed and only 25 other cases of true antrolithiasis were encountered. The clinical and radiological features of antroliths, as well as differential diagnosis were discussed. Antrolithiasis should be considered in any case of sinusitis, that does not respond to appropriate medical therapy.

Comparison of reliabilities of the delayed images of helical renal CT in detecting small renal masses.

The reliabilities of the delayed images of helical computed tomography (CT) in detecting renal mass lesions of 30 mm or less in diameter was compared. Nephrographic, excretory and nephrographic+excretory phase images of all patients were evaluated separately to detect mass lesions of < or = 5 and 5-30 mm. There was not any statistically significant difference in the results of three groups. Nephrographic, excretory and nephrographic + excretory phase images are not different from or superior to each other in lesion detection.

Diagnostic value of sonohysterography in the evaluation of submucosal fibroids and endometrial polyps.

AIMS: To evaluate the diagnostic value of sonohysterography in the evaluation of submucosal fibroids and endometrial polyps. METHODS: Thirty-two women whose preliminary transvaginal ultrasound suggested endometrial abnormality underwent sonohysterography. The findings were then compared with histopathological results. RESULTS: The sonohysterographic diagnosis was fibroid in seven patients, endometrial polyp in 23 patients and simple hyperplasia in two patients. Histopathological findings confirmed our diagnosis in all except three patients with endometrial polyps, who had normal secretory endometrium. Sonohysterography was found to have a sensitivity of 100%, a positive predictive value of 90% and diagnostic accuracy of 90.6%. CONCLUSION: Sonohysterography is a useful, minimally invasive and accurate technique to evaluate the pathologies involving endometrium and uterine cavity.