Exploring the diagnostic value of ultrasound radiomics for neonatal respiratory distress syndrome

BACKGROUND

Neonatal respiratory distress syndrome (NRDS) is a prevalent cause of respiratory failure and death among newborns, and prompt diagnosis is imperative. Historically, diagnosis of NRDS relied mostly on typical clinical manifestations, chest X-rays, and CT scans. However, recently, ultrasound has emerged as a valuable and preferred tool for aiding NRDS diagnosis. Nevertheless, evaluating lung ultrasound imagery necessitates rigorous training and may be subject to operator-dependent bias, limiting its widespread use. As a result, it is essential to investigate a new, reliable, and operator-independent diagnostic approach that does not require subjective factors or operator expertise. This article aims to explore the diagnostic potential of ultrasound-based radiomics in differentiating NRDS from other non-NRDS lung disease.

METHODS

A total of 150 neonatal lung disease cases were consecutively collected from the department of neonatal intensive care unit of the Quanzhou Maternity and Children's Hospital, Fujian Province, from September 2021 to October 2022. Of these patients, 60 were diagnosed with NRDS, whereas 30 were diagnosed with neonatal pneumonia, meconium aspiration syndrome (MAS), and transient tachypnea (TTN). Two ultrasound images with characteristic manifestations of each lung disease were acquired and divided into training (n = 120) and validation cohorts (n = 30) based on the examination date using an 8:2 ratio. The imaging texture features were extracted using PyRadiomics and, after the screening, machine learning models such as random forest (RF), logistic regression (LR), K-nearest neighbors (KNN), support vector machine (SVM), and multilayer perceptron (MLP) were developed to construct an imaging-based diagnostic model. The diagnostic efficacy of each model was analyzed. Lastly, we randomly selected 282 lung ultrasound images and evaluated the diagnostic efficacy disparities between the optimal model and doctors across differing levels of expertise.

RESULTS

Twenty-two imaging-based features with the highest weights were selected to construct a predictive model for neonatal respiratory distress syndrome. All models exhibited favorable diagnostic performances. Analysis of the Youden index demonstrated that the RF model had the highest score in both the training (0.99) and validation (0.90) cohorts. Additionally, the calibration curve indicated that the RF model had the best calibration (P = 0.98). When compared to the diagnostic performance of experienced and junior physicians, the RF model had an area under the curve (AUC) of 0.99; however, the values for experienced and junior physicians were 0.98 and 0.85, respectively. The difference in diagnostic efficacy between the RF model and experienced physicians was not statistically significant (P = 0.24), whereas that between the RF model and junior physicians was statistically significant (P < 0.0001).

CONCLUSION

The RF model exhibited excellent diagnostic performance in the analysis of texture features based on ultrasound radiomics for diagnosing NRDS.

Comparative diagnostic accuracy of the IOTA SRR and LR2 scoring systems for discriminating between malignant and Benign Adnexal masses by junior physicians in Chinese patients: a retrospective observational study

BACKGROUND

The accuracy of ultrasound in distinguishing benign from malignant adnexal masses is highly correlated with the experience of ultrasound physicians. In China, most of ultrasound differentiation is done by junior physicians.

PURPOSE

To compare the diagnostic performance of the International Ovarian Tumour Analysis (IOTA) Simple Rules Risk (SRR) and IOTA Logistic Regression Model 2 (LR2) scoring systems in Chinese patients with adnexal masses.

METHODS

Retrospective analysis of ovarian cancer tumor patients who underwent surgery at a hospital in China from January 2016 to December 2021. Screening patients with at least one adnexal mass on inclusion and exclusion criteria. Two trained junior physicians evaluated each mass using the two scoring systems. A receiver operating characteristic curve was used to test the diagnostic performance of each system.

RESULTS

A total of 144 adnexal masses were retrospectively collected. Forty masses were histologically diagnosed as malignant. Compared with premenopausal women, postmenopausal women had a much higher rate of malignant masses. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) of the SRR was 97.5% (95% CI: 86.8 -99.9%), 82.7% (95% CI: 74.0 -89.4%), 68.4% (95% CI: 58.7 -76.8%) and 98.9% (95% CI: 92.5 -99.8%). The sensitivity, specificity, PPV, NPV of the LR2 were 90.0% (95% CI: 76.5 -97.2%), 89.4% (95% CI: 81.9 -94.6%), 76.6% (95% CI: 65.0 -85.2%), and 95.9% (95% CI: 90.2 -98.3%). There was good agreement between two scoring systems, with 84.03% total agreement and a kappa value of 0.783 (95% CI: 0.70-0.864). The areas under the curve for predicting malignant tumours using SRR and LR2 were similar for all patients (P > 0.05 ).

CONCLUSION

The two scoring systems can effectively distinguish benign from malignant adnexal masses. Both scoring systems have high diagnostic efficacy, and diagnostic efficacy is stable, which can provide an important reference for clinical decision making.

Study on diagnosis of thyroid nodules based on convolutional neural network

OBJECTIVE

An artificial intelligence (AI) algorithm based on convolutional neural networks was used in ultrasound diagnosis in order to evaluate its performance in judging the nature of thyroid nodules and nodule classification.

METHODS

A total of 105 patients with thyroid nodules confirmed by surgery or biopsy were retrospectively analyzed. The properties, characteristics, and classification of thyroid nodules were evaluated by sonographers and by AI to obtain combined diagnoses. Receiver operating characteristic curves were generated to evaluate the performance of AI, the sonographer, and their combined effort in diagnosing the nature of thyroid nodules and classifying their characteristics. In the diagnosis of thyroid nodules with solid components, hypoechoic appearance, indistinct borders, Anteroposterior/transverse diameter ratio > 1(A/T > 1), and calcification performed by sonographers and by AI, the properties exhibited statistically significant differences.

RESULTS

Sonographers had a sensitivity of 80.7%, specificity of 73.7%, accuracy of 79.0%, and area under the curve (AUC) of 0.751 in the diagnosis of benign and malignant thyroid nodules. AI had a sensitivity of 84.5%, specificity of 81.0%, accuracy of 84.7%, and AUC of 0.803. The combined AI and sonographer diagnosis had a sensitivity of 92.1%, specificity of 86.3%, accuracy of 91.7%, and AUC of 0.910.

CONCLUSION

The efficacy of a combined diagnosis for benign and malignant thyroid nodules is higher than that of an AI-based diagnosis alone or a sonographer-based diagnosis alone. The combined diagnosis can reduce unnecessary fine-needle aspiration biopsy procedures and better evaluate the necessity of surgery in clinical practice.

Differential Diagnosis of DCIS and Fibroadenoma Based on Ultrasound Images: a Difference-Based Self-Supervised Approach

Differentiation of ductal carcinoma in situ (DCIS, a precancerous lesion of the breast) from fibroadenoma (FA) using ultrasonography is significant for the early prevention of malignant breast tumors. Radiomics-based artificial intelligence (AI) can provide additional diagnostic information but usually requires extensive labeling efforts by clinicians with specialized knowledge. This study aims to investigate the feasibility of differentially diagnosing DCIS and FA using ultrasound radiomics-based AI techniques and further explore a novel approach that can reduce labeling efforts without sacrificing diagnostic performance. We included 461 DCIS and 651 FA patients, of whom 139 DCIS and 181 FA patients constituted a prospective test cohort. First, various feature engineering-based machine learning (FEML) and deep learning (DL) approaches were developed. Then, we designed a difference-based self-supervised (DSS) learning approach that only required FA samples to participate in training. The DSS approach consists of three steps: (1) pretraining a Bootstrap Your Own Latent (BYOL) model using FA images, (2) reconstructing images using the encoder and decoder of the pretrained model, and (3) distinguishing DCIS from FA based on the differences between the original and reconstructed images. The experimental results showed that the trained FEML and DL models achieved the highest AUC of 0.7935 (95% confidence interval, 0.7900-0.7969) on the prospective test cohort, indicating that the developed models are effective for assisting in differentiating DCIS from FA based on ultrasound images. Furthermore, the DSS model achieved an AUC of 0.8172 (95% confidence interval, 0.8124-0.8219), indicating that our model outperforms the conventional radiomics-based AI models and is more competitive.

Ultrasound-assisted diagnosis of Langerhans cell hyperplasia of the sternum: A case report

Langerhans cell hyperplasia is a group of diseases characterized by the proliferation or dissemination of the Langerhans cell, which can come in the form of localized benign lesions, or extensive disseminated invasive neoplastic lesions. These lesions mainly invade the patient's bone. In this paper, we describe the case of a 3-year-old boy who was admitted to the pediatric department with sternum pain. Following a focused sternum ultrasound, a diagnosis was made of Langerhans cell histiocytosis.

Hyperreactio luteinalis mimicking malignancy during pregnancy with elevated CA-125

OBJECTIVE

To report a case with benign bilateral ovarian tumor during pregnancy mimicking malignancy.

CASE REPORT

A 32-year-old women at 20 weeks gestation with large bilateral adnexal masses found on prenatal ultrasound. The cysts had been growing gradually over the course of the pregnancy. MRI show huge multiple cysts in both ovaries. CA-125 was elevated at 260 U/mL. Due to initial impression was malignancy, an excisional surgery was done. Pathology revealed multiple luteinized granulosa cells with benign nature.

CONCLUSION

Hyperreactio luteinalis (HL) is often asymptomatic and discovered incidentally on ultrasound or at the time of cesarean section. As the lesions are self-resolving, management is conservative and surgical intervention is required only in cases with severe complications. HL can be mistaken for malignancy, especially in cases in which the tumor marker CA-125 is elevated, leading to inadvertent surgery.

First Trimester Ultrasound Diagnosis of Right Aortic Arch (RAA)

Objectives. In the present research we proposed to evaluate the cases diagnosed in the first trimester of pregnancy by ultrasound with RAA, knowing the fact that although, in most cases the disease is isolated and asymptomatic, in some cases the presence of RAA can be associated with other fetal structural abnormalities that must be detected and monitored during pregnancy. We established correlations between the postnatal or anatomopathological examination (in cases ended by therapeutic abortion) and the presence of RAA detected in the first trimester. Material and method. We conducted a retrospective analytical study that investigated the role of the RAA early detection (isolated or associated with other cardiac abnormalities) for a correct pregnancy monitoring and postpartum management. Between 2012 and 2018, patients admitted in the first Obstetrics and Gynecology Clinic-the Prenatal Diagnostic Unit-of the Emergency County Hospital from Craiova, were evaluated in the first trimester of pregnancy for genetic abnormalities and early morphology. The study material was represented by the patient’s medical records (observation sheets, surgical protocol records, anatomopathological diagnostic records). The obtained information was stored in Microsoft Excel files and statistically processed. Results. During the study period, 14 cases with right aortic arch were diagnosed in the first and second trimester of pregnancy. 4 cases were detected in the first trimester: 2 cases (50%) presented left ductus arteriosus (DA)-RAA type 2 (“U” sign) and 2 cases (50%) presented right DA-RAA type 1 (mirror image-“V” sign). RAA type 1 associated Tetralogy of Fallot in one case (25%) and in another one case (25%) the anomaly was isolated. RAA type 2 associated atrio-ventricular septal defect (AVSD) in one case (25%) and in another one case (25%) the anomaly was isolated. There were no fetal extracardiac structural abnormalities associated with the RAA diagnosis in the first trimester. Conclusions. Over a seven years study period (2012-2018), 14 cases with RAA in the first and second trimester of pregnancy were detected. In the low-risk pregnancies group, the first trimester incidence of the RAA was 0.11% and the association of congenital heart abnormalities was 50%.

Comparison and preliminary discussion of the reasons for the differences in diagnostic performance and unnecessary FNA biopsies between the ACR TIRADS and 2015 ATA guidelines

OBJECTIVES

(1) To compare the American College of Radiology (ACR) thyroid imaging reporting and data system (TIRADS) and American Thyroid Association (ATA) guidelines for thyroid nodules with regard to diagnostic performance and effectiveness at reducing the number of fine-needle aspiration (FNA) biopsies and to preliminarily discuss the reasons for the differences and (2) to compare the diagnostic performance of the two guidelines in the subgroup of nodules <1 cm in diameter.

MATERIALS AND METHODS

In the present study, 1000 thyroid nodules in 894 consecutive patients with final diagnoses were included; these thyroid nodules were investigated via FNA biopsies in our hospital. The ultrasound (US) features of the thyroid nodules were reviewed and stratified according to the categories defined by the ACR TIRADS and ATA guidelines.

RESULTS

Compared with the ACR TIRADS guidelines, the ATA guidelines had a higher sensitivity (93.4% (P < 0.001)) and a larger negative predictive value (NPV) (85.3% (P= 0.034)). Compared with the ATA guidelines, the ACR TIRADS guidelines had a higher specificity (66.0% (P < 0.001)), a greater PPV (73.6% (P= 0.001)), and greater accuracy (75.5% (P= 0.017)). Compared with the ATA guidelines, the ACR TIRADS guidelines resulted in significantly fewer unnecessary FNA biopsies (P= 0.007).

CONCLUSIONS

This study suggests that both the ACR TIRADS and ATA guidelines have unique strengths with regard to their diagnostic performance. In terms of reducing the number of FNA biopsies, the ACR TIRADS guidelines were superior to the ATA guidelines.

Ultrasound classification and clinical analysis of ovarian pregnancy: A study of 12 cases

OBJECTIVE

To evaluate the clinical significance of preoperative ultrasound diagnosis and classification of ovarian pregnancy (OP).

METHODS

The ultrasonographic reports, medical records, and operative summaries were reviewed for twelve women with a confirmed diagnosis of OP. According to the ultrasonographic appearance, OP was classified into two types. For every type, we analyzed the possibility and clinical significance of preoperative ultrasound diagnosis, combining with its clinical manifestations and treatments.

RESULTS

According to sonographic features, twelve cases of OP can be classified into ruptured type (n = 6) and unruptured type (n = 6), the latter was subclassified into embryo sac type (n = 2) and non-homogeneous mass type (n = 4). All the unruptured OP have the characteristic solid hyperechoic rings or masses, and 66.7% (4/6) were correctvly diagnosed by preoperative ultrasound. No characteristic ultrasonogram was detected in ruptured OP which were all diagnosed as ruptured ectopic pregnancy (EP) or corpus luteum by preoperative ultrasound. The diagnostic and surgical procedures of four cases diagnosed by preoperative ultrasound were all laparoscopy and removal of the gestational products, and their average hemoperitoneum, operation time, hospital days was 313 ± 278 ml, 57 ± 9 min, and 4.25 ± 0.5days, respectively. While ruptured OP cases (6 cases diagnosed at first visit and 1 underdiagnosed but ruptured after 6 days), the diagnostic procedures was laparoscopy(3/7) or laparotomy(4/7), the surgical procedure was removal of the gestational products(2/7), wedge resection(3/7), or adenexectomy(2/7), and their average hemoperitoneum, operation time, and hospital days was 1914 ± 1059 ml, 93 ± 17 min, and 5.9 ± 1.3days, respectively.

CONCLUSIONS

Ultrasound plays a significant role in diagnosis of OP, and part of the unruptured OP based on the typical sonographic characteristics could be correctly diagnosed by an experienced sonographer, this is beneficial and effective in terms of the risk of patient's operation and life. Whereas ruptured OP were generally diagnosed as ruptured EP or corpus luteum because there were no characteristic ultrasound manifestations.

Detection and Prevention of Perinatal Infection: Cytomegalovirus and Zika Virus

Congenital cytomegalovirus is the most common viral congenital infection, and affects up to 2% of neonates. Significant sequelae may develop after congenital cytomegalovirus, including hearing loss, cognitive defects, seizures, and death. Zika virus is an emerging virus with perinatal implications; a congenital Zika virus syndrome has been identified, and includes findings such as microcephaly, fetal nervous system abnormalities, and neurologic sequelae after birth. Screening, diagnosis, prevention, and treatment of these perinatal infections are reviewed in this article.

Ultrasound Diagnosis of Postoperative Complications of Nerve Repair

BACKGROUND

Peripheral nerve injuries often undergo surgical repair, but poor postoperative functional recovery is frequently observed.

CASE DESCRIPTION

We describe 4 cases of traumatic nerve lesions in whom postoperative recovery was prevented by complications such as detachment of nerve sutures or neuroma growth. To the best of our knowledge, no similar cases have been reported in literature so far. It is important to obtain an early diagnosis of such condition because it prevents recovery and delays reintervention, which should be performed before complete muscle denervation and atrophy.

CONCLUSION

Nerve ultrasound is a valuable tool in traumatic nerve injury and has proven to be useful in postoperative follow-up, especially in diagnosing surgical complications such as detachment of nerve direct sutures.

Effect of sitagliptin on tissue characteristics of the carotid wall in patients with type 2 diabetes: a post hoc sub-analysis of the sitagliptin preventive study of intima-media thickness evaluation (SPIKE)

BACKGROUND

Ultrasonic gray-scale median (GSM) of the carotid wall reflects its composition and low-GSM carotid plaque is considered to be vulnerable. This study aimed to evaluate the effect of sitagliptin, a dipeptidyl peptidase-4 inhibitor, on the longitudinal change in GSM, an index of the tissue characteristics of the carotid wall, in patients with type 2 diabetes mellitus (T2DM).

METHODS

This is a post hoc sub-analysis using data obtained from the SPIKE trial, a randomized controlled trial that demonstrated the beneficial effect of sitagliptin on the progression of carotid intima-media thickness in patients with T2DM. A total of 274 T2DM patients with no past history of apparent cardiovascular disease (137 in the sitagliptin treatment group and 137 in the conventional treatment group) were enrolled. The primary outcome was the change from baseline in mean GSM-CCA during the 104-week treatment period.

RESULTS

The mean GSM-CCA significantly increased in the sitagliptin treatment group (adjusted ΔGSM = 2.40 ± 1.19 [mean ± SE], p = 0.044) but not in the conventional treatment group (adjusted ΔGSM = 1.32 ± 1.19, p = 0.27). However, there was no significant difference in changes in mean GSM-CCA between the treatment groups.

CONCLUSIONS

A post hoc sub-analysis suggests that the tissue characteristics of the carotid arterial wall were improved in the sitagliptin treatment group during the 104-week treatment period, but not in the conventional treatment group. However, there was no between-group difference in the changes of GSM values between the two treatment groups. Prespecified studies with large sample sizes would be necessary to confirm our findings. Trial registration UMIN000028664, Registered 15 August 2017 ("retrospectively registered").

Agenesis of gall bladder in laparoscopic cholecystectomy-A case report

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Agenesis of the gall bladder is extremely rare, A high index of suspicion is mandatory for diagnosis.

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The awareness of physician, radiologist and the surgeons of the possibility of this condition and of the problems posed by it.

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The surgeon to attempt confirmation of diagnosis, when suspected, by nonoperative methods.

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Non-visualized gall bladder in laparoscopic cholecystectomy is challenging.

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No extensive dissection was needed or change to open method unless you sure that the gall bladder is present.

Introduction

Agenesis of gallbladder is a rare congenital anomaly of biliary tree that may be associated with other biliary and extra biliary congenital anomalies.

Case presentation

A 43- year- old female presented with a 4 months history of upper abdominal pain associated with nausea and vomiting. It was associated with dyspeptic symptoms and become worse following ingestion of high-fat meal contents. Clinically, a differential of gall stone disease was considered. Ultrasonography of abdomen revealed a contracted gallbladder with multiple stones with normal wall thickness, so the fact of clinical diagnosis considering finding cholithiasis. She was submitted to laparoscopic exploration which revealed that the gall bladder was absent within gall bladder fossa.

Discussion

In this case, the differential of cholithiasis symptoms considered support by ultrasonography, symptomatic gall stones presented more than half of cases of gall bladder agenesis, Diagnosis of gall bladder disease usually done by ultrasound modality, it must be done by expert one. Awareness of this entity by clinicians, surgeons and radiologists are essential because many of these patients present with biliary symptoms and have unnecessary operations.

Conclusion

Agenesis of gallbladder should be kept in mind whenever the gall bladder was improperly visualized in routine imaging methods. Ultrasonography operated dependent we must not depend on single one or even multiple done by the same person. Avoid a needless surgical exploration, which might be risky. Non-visualized gall bladder during laparoscopic cholecystectomy is challenging should not convert to open unless sure that the gall bladder was present.

Adenomyosis in infertile women: prevalence and the role of 3D ultrasound as a marker of severity of the disease

BACKGROUND

Adenomyosis is linked to infertility, but the mechanisms behind this relationship are not clearly established. Similarly, the impact of adenomyosis on ART outcome is not fully understood. Our main objective was to use ultrasound imaging to investigate adenomyosis prevalence and severity in a population of infertile women, as well as specifically among women experiencing recurrent miscarriages (RM) or repeated implantation failure (RIF) in ART.

METHODS

Cross-sectional study conducted in 1015 patients undergoing ART from January 2009 to December 2013 and referred for 3D ultrasound to complete study prior to initiating an ART cycle, or after ≥3 IVF failures or ≥2 miscarriages at diagnostic imaging unit at university-affiliated private IVF unit. Adenomyosis was diagnosed in presence of globular uterine configuration, myometrial anterior-posterior asymmetry, heterogeneous myometrial echotexture, poor definition of the endometrial-myometrial interface (junction zone) or subendometrial cysts. Shape of endometrial cavity was classified in three categories: 1.-normal (triangular morphology); 2.- moderate distortion of the triangular aspect and 3.- "pseudo T-shaped" morphology.

RESULTS

The prevalence of adenomyosis was 24.4 % (n = 248) [29.7 % (94/316) in women aged ≥40 y.o and 22 % (154/699) in women aged <40 y.o., p = 0.003)]. Its prevalence was higher in those cases of recurrent pregnancy loss [38.2 % (26/68) vs 22.3 % (172/769), p < 0.005] and previous ART failure [34.7 % (107/308) vs 24.4 % (248/1015), p < 0.0001]. The presence of adenomyosis has been shown to be associated to endometriosis [35.1 % (34/97)]. Adenomyosis was diagnosed as a primary finding "de novo" in 80.6 % (n = 200) of the infertile patients. The impact on the uterine cavity was mild, moderate and severe in 63.7, 22.6 and 10.1 % of the cases, respectively.

CONCLUSIONS

Our results indicate that adenomyosis is a clinical condition with a high prevalence that may affect the reproductive results. The described severity criteria may help future validating studies for better counseling of infertile couples.

A Tactile Sensor for Ultrasound Imaging Systems

Medical ultrasound systems are capable of monitoring a variety of health conditions while avoiding invasive procedures. However this function is complicated by ultrasound contrast of the tissue varying with contact pressure exerted by the probe. The knowledge of the contact pressure is beneficial for a variety of screening and diagnostic procedures involving ultrasound. This paper introduces a solid-state sensor array which measures the contact pressure distribution between the probe and the tissue marginally affecting the ultrasound imaging capabilities. The probe design utilizes the dielectrostriction mechanism which relates the change in dielectric properties of the sensing layer to deformation. The concept, structure, fabrication, and performance of this sensor array are discussed. The prototype device is highly tolerant to overloads (>1 MPa tested) and provides stress measurements in the range of 0.14 to 10 kPa. Its loss of ultrasound transmissivity is less 3dB at 9 MHz ultrasound frequency. This performance is satisfactory for clinical and biomedical research in ultrasound image formation and interpretation, however for commercial product, a higher ultrasound transmissivity is desired. Directions for improving the sensor ultrasound transparency and electrical performance are discussed. The sensor array described in this paper has been developed specifically for ultrasound diagnosis during breast cancer screening. However, the same sensing mechanism, similar configuration and sensor array structure can be applied to other applications involving ultrasound tools for medical diagnostics.

Echocardiographic presentation of anomalous origin of the left coronary artery from the pulmonary artery

In the 1970s, diagnosing anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) was often uncertain using imaging alone; however, with the advances in high-frequency transducers, advanced image processing, and other ultrasound modalities such as Doppler colour flow imaging, tissue Doppler imaging, and speckle tracking to asses regional wall motion abnormalities, modern echocardiography now permits accurate diagnosis of ALCAPA with greater certainty. Although many consider ultrasound to be the only imaging test necessary if there is a question as to the diagnosis, other imaging modalities such as MRI, CT, and cardiac catheterisation with angiography remain valuable complementary tests, especially in older patients.

Sensitivity, Specificity and Accuracy of Ultrasound in Diagnosis of Breast Cancer Metastasis to the Axillary Lymph Nodes in Chinese Patients

The use of ultrasound in the diagnosis of axillary lymph node metastases from breast cancer in a Chinese population was investigated. Data for 1,049 with breast cancer were retrospectively collected. All patients had undergone pre-operative axillary ultrasound and then axillary lymph node dissection. The sensitivity, specificity and accuracy of axillary ultrasound in this cohort were 69.4%, 81.8% and 77.0%, respectively. The overall false-negative rate of ultrasound images was 30.6% (123/402). False-negative ultrasound rates for pathologic N1, N2 and N3 patients were 46.2%, 21.8% and 9.3%, respectively. In patients with stage T1 disease and fewer than three metastatic lymph nodes, the false-negative ultrasound rate was 52.2% (47/90). Moreover, breast cancer patients with a false-negative axillary ultrasound were more likely to have a large tumor (p < 0.001) and high tumor grade (p = 0.009). However, there were no statistically significant differences between accuracy of axillary ultrasound and age of patients or experiences of ultrasound practitioners. In conclusion, the sensitivity, specificity and accuracy of ultrasound in the diagnosis of breast cancer metastasis to the axillary lymph nodes in Chinese patients were assessed. These data could help us to carefully use axillary ultrasound to diagnose and predict breast cancer axillary lymph node metastasis.

Medical diagnosis in resource-poor tropical countries

When working in healthcare centers in developing countries where diagnostic resources are limited, clinical skills are of considerable importance. This study presents the diagnostic tools available in resource-poor areas. Anamnesis and physical examination are key components for reaching a correct diagnosis. The laboratory has at its disposal hemograms, basic blood chemistry and urinalysis. The available basic microbiological tests are the study of fresh feces, smears for malaria, direct smears for bacilli in sputum and Gram staining of clinical exudates. Basic radiography of the chest, abdomen, bones and soft tissues are of considerable usefulness but are not available in all centers. Ultrasonography can be of considerable usefulness due to its simplicity and versatility. The diagnosis in low resource conditions should sharpen our clinical skills and should be supported by the use of additional basic tests.

Ultrasonic diagnosis of solid pseudopapillary tumor of the pancreas: Causes of misdiagnosis

AIM: To study the ultrasound diagnosis and causes of misdiagnosis of solid pseudopapillary tumor of pancreas (SPTP).

METHODS: Ultrasonic and clinical data for 11 patients with pathologically confirmed SPTP who underwent surgical treatment from June 2008 to June 2011 at our hospital were analyzed retrospectively.

RESULTS: All cases had a single round or oval-shaped, mixed slightly low echo mass. The tumor had a clear boundary in 9 cases and a complete capsule in 8 cases. Ten cases had no post-tumor echo attenuation. Adjacent tissue or organ compression and displacement were observed in 9 cases. Eight cases showed little blood flow in and around the tumor. All cases showed no dilatation in the pancreatic duct and bile duct, except for 1 case showing slight widening of distal pancreatic duct. Five cases of SPTP were diagnosed by ultrasound before operation; three cases were highly suspected to have SPTP after fully considering the age, sex, and CT findings. Because of irregular tumor morphology and capsule, local thickening or lobulated convex growth, unclear surrounding tissue, complicated structure and echo of internal tumor, three cases were misdiagnosed.

CONCLUSION: SPTP display a group of "sonographic signs", which are important clues to and basis for the diagnosis of SPTP. Main reasons for misdiagnosis are complicated and diverse.