ChatGPT in radiology: A systematic review of performance, pitfalls, and future perspectives

PURPOSE

The purpose of this study was to systematically review the reported performances of ChatGPT, identify potential limitations, and explore future directions for its integration, optimization, and ethical considerations in radiology applications.

MATERIALS AND METHODS

After a comprehensive review of PubMed, Web of Science, Embase, and Google Scholar databases, a cohort of published studies was identified up to January 1, 2024, utilizing ChatGPT for clinical radiology applications.

RESULTS

Out of 861 studies derived, 44 studies evaluated the performance of ChatGPT; among these, 37 (37/44; 84.1%) demonstrated high performance, and seven (7/44; 15.9%) indicated it had a lower performance in providing information on diagnosis and clinical decision support (6/44; 13.6%) and patient communication and educational content (1/44; 2.3%). Twenty-four (24/44; 54.5%) studies reported the proportion of ChatGPT's performance. Among these, 19 (19/24; 79.2%) studies recorded a median accuracy of 70.5%, and in five (5/24; 20.8%) studies, there was a median agreement of 83.6% between ChatGPT outcomes and reference standards [radiologists' decision or guidelines], generally confirming ChatGPT's high accuracy in these studies. Eleven studies compared two recent ChatGPT versions, and in ten (10/11; 90.9%), ChatGPTv4 outperformed v3.5, showing notable enhancements in addressing higher-order thinking questions, better comprehension of radiology terms, and improved accuracy in describing images. Risks and concerns about using ChatGPT included biased responses, limited originality, and the potential for inaccurate information leading to misinformation, hallucinations, improper citations and fake references, cybersecurity vulnerabilities, and patient privacy risks.

CONCLUSION

Although ChatGPT's effectiveness has been shown in 84.1% of radiology studies, there are still multiple pitfalls and limitations to address. It is too soon to confirm its complete proficiency and accuracy, and more extensive multicenter studies utilizing diverse datasets and pre-training techniques are required to verify ChatGPT's role in radiology.

Ferumoxytol-Enhanced Cardiac Cine MRI Reconstruction Using a Variable-Splitting Spatiotemporal Network

BACKGROUND

Balanced steady-state free precession (bSSFP) imaging is commonly used in cardiac cine MRI but prone to image artifacts. Ferumoxytol-enhanced (FE) gradient echo (GRE) has been proposed as an alternative. Utilizing the abundance of bSSFP images to develop a computationally efficient network that is applicable to FE GRE cine would benefit future network development.

PURPOSE

To develop a variable-splitting spatiotemporal network (VSNet) for image reconstruction, trained on bSSFP cine images and applicable to FE GRE cine images.

STUDY TYPE

Retrospective and prospective.

SUBJECTS

41 patients (26 female, 53 ± 19 y/o) for network training, 31 patients (19 female, 49 ± 17 y/o) and 5 healthy subjects (5 female, 30 ± 7 y/o) for testing.

FIELD STRENGTH/SEQUENCE

1.5T and 3T, bSSFP and GRE.

ASSESSMENT

VSNet was compared to VSNet with total variation loss, compressed sensing and low rank methods for 14× accelerated data. The GRAPPA×2/×3 images served as the reference. Peak signal-to-noise-ratio (PSNR), structural similarity index (SSIM), left ventricular (LV) and right ventricular (RV) end-diastolic volume (EDV), end-systolic volume (ESV), and ejection fraction (EF) were measured. Qualitative image ranking and scoring were independently performed by three readers. Latent scores were calculated based on scores of each method relative to the reference.

STATISTICS

Linear mixed-effects regression, Tukey method, Fleiss' Kappa, Bland-Altman analysis, and Bayesian categorical cumulative probit model. A P-value <0.05 was considered statistically significant.

RESULTS

VSNet achieved significantly higher PSNR (32.7 ± 0.2), SSIM (0.880 ± 0.004), rank (2.14 ± 0.06), and latent scores (-1.72 ± 0.22) compared to other methods (rank >2.90, latent score < -2.63). Fleiss' Kappa was 0.52 for scoring and 0.61 for ranking. VSNet showed no significantly different LV and RV ESV (P = 0.938) and EF (P = 0.143) measurements, but statistically significant different (2.62 mL) EDV measurements compared to the reference.

CONCLUSION

VSNet produced the highest image quality and the most accurate functional measurements for FE GRE cine images among the tested 14× accelerated reconstruction methods.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: Stage 1.

How AI Responds to Common Lung Cancer Questions: ChatGPT vs Google Bard

Background The recent release of large language models (LLMs) for public use, such as ChatGPT and Google Bard, has opened up a multitude of potential benefits as well as challenges. Purpose To evaluate and compare the accuracy and consistency of responses generated by publicly available ChatGPT-3.5 and Google Bard to non-expert questions related to lung cancer prevention, screening, and terminology commonly used in radiology reports based on the recommendation of Lung Imaging Reporting and Data System (Lung-RADS) v2022 from American College of Radiology and Fleischner society. Materials and Methods Forty of the exact same questions were created and presented to ChatGPT-3.5 and Google Bard experimental version as well as Bing and Google search engines by three different authors of this paper. Each answer was reviewed by two radiologists for accuracy. Responses were scored as correct, partially correct, incorrect, or unanswered. Consistency was also evaluated among the answers. Here, consistency was defined as the agreement between the three answers provided by ChatGPT-3.5, Google Bard experimental version, Bing, and Google search engines regardless of whether the concept conveyed was correct or incorrect. The accuracy among different tools were evaluated using Stata. Results ChatGPT-3.5 answered 120 questions with 85 (70.8%) correct, 14 (11.7%) partially correct, and 21 (17.5%) incorrect. Google Bard did not answer 23 (19.1%) questions. Among the 97 questions answered by Google Bard, 62 (51.7%) were correct, 11 (9.2%) were partially correct, and 24 (20%) were incorrect. Bing answered 120 questions with 74 (61.7%) correct, 13 (10.8%) partially correct, and 33 (27.5%) incorrect. Google search engine answered 120 questions with 66 (55%) correct, 27 (22.5%) partially correct, and 27 (22.5%) incorrect. The ChatGPT-3.5 is more likely to provide correct or partially answer than Google Bard, approximately by 1.5 folds (OR = 1.55, P = 0.004). ChatGPT-3.5 and Google search engine were more likely to be consistent than Google Bard by approximately 7 and 29 folds (OR = 6.65, P = 0.002 for ChatGPT and OR = 28.83, P = 0.002 for Google search engine, respectively). Conclusion Although ChatGPT-3.5 had a higher accuracy in comparison with the other tools, neither ChatGPT nor Google Bard, Bing and Google search engines answered all questions correctly and with 100% consistency.

Cardiac Outpouchings: Practical Approach to Normal Variants and Pathologic Conditions at CT and MRI

Numerous entities, both structural and pathologic, can manifest as a contrast material- or blood-filled cardiac outpouching at imaging. These outpouchings often resemble one another and are frequently unfamiliar to imagers and clinicians, creating uncertainty when detected. Furthermore, the diagnostic criteria for conditions such as hernia, aneurysm, pseudoaneurysm, and diverticulum have not been consistently applied in studies and reports cited in the literature describing these outpouchings, adding to the confusion among general and cardiothoracic imagers. Pouches and outpouchings are commonly found incidentally on thoracic and abdominal CT scans obtained for other reasons. Many pouches and outpouchings can be confidently diagnosed or ignored at routine imaging, whereas others may require further evaluation with electrocardiographically gated CT, cardiac MRI, or echocardiography for a more definitive diagnosis. It is easiest to group and diagnose these entities on the basis of their cardiac chamber location or their involvement with the interatrial and interventricular septa. Ancillary features, such as motion, morphology, neck and body size, presence or absence of thrombus, and late gadolinium enhancement characteristics, are important in reaching a correct diagnosis. The aim of this article is to provide a practical guide to pouches and outpouchings of the heart. Each entity is defined according to its cause, imaging characteristics, clinical significance, and relevant associated findings. Mimics of cardiac pouches and outpouchings such as the Bachmann bundle, atrial veins, and thebesian vessels also are briefly discussed. Quiz questions for this article are available in the supplemental material. ^©RSNA, 2023.

Contrast-enhanced MR Angiography without Gadolinium-based Contrast Material: Clinical Applications Using Ferumoxytol

Vascular imaging can be challenging because of the wide variability of contrast dynamics in different vascular territories and potential safety concerns in patients with renal insufficiency or allergies. Off-label diagnostic use of ferumoxytol, a superparamagnetic iron nanoparticle approved for therapy, is a promising alternative to gadolinium-based contrast agents for MR angiography (MRA). Ferumoxytol has exhibited a reassuring safety profile when used within the dose range recommended for diagnostic imaging. Because of its prolonged and stable intravascular residence, ferumoxytol can be used in its steady-state distribution for a wide variety of imaging indications, including some where conventional MRA is unreliable. In this article, authors discuss some of the major vascular applications of ferumoxytol and highlight how it may be used to provide highly diagnostic images and improve the quality, workflow, and reliability of vascular imaging. Keywords: MR Angiography, MRI Contrast Agent, Cardiac, Vascular © RSNA, 2022.

Severe COVID-19 Pneumonia of Single Transplant Lung Sparing Native Fibrotic Lung

Supplemental Digital Content is available in the text.

Automatic segmentation of peripheral arteries and veins in ferumoxytol-enhanced MR angiography

PURPOSE

To automate the segmentation of the peripheral arteries and veins in the lower extremities based on ferumoxytol-enhanced MR angiography (FE-MRA).

METHODS

Our automated pipeline has 2 sequential stages. In the first stage, we used a 3D U-Net with local attention gates, which was trained based on a combination of the Focal Tversky loss with region mutual loss under a deep supervision mechanism to segment the vasculature from the high-resolution FE-MRA datasets. In the second stage, we used time-resolved images to separate the arteries from the veins. Because the ultimate segmentation quality of the arteries and veins relies on the performance of the first stage, we thoroughly evaluated the different aspects of the segmentation network and compared its performance in blood vessel segmentation with currently accepted state-of-the-art networks, including Volumetric-Net, DeepVesselNet-FCN, and Uception.

RESULTS

We achieved a competitive F1 = 0.8087 and recall = 0.8410 for blood vessel segmentation compared with F1 = (0.7604, 0.7573, 0.7651) and recall = (0.7791, 0.7570, 0.7774) obtained with Volumetric-Net, DeepVesselNet-FCN, and Uception. For the artery and vein separation stage, we achieved F1 = (0.8274/0.7863) in the calf region, which is the most challenging region in peripheral arteries and veins segmentation.

CONCLUSION

Our pipeline is capable of fully automatic vessel segmentation based on FE-MRA without need for human interaction in <4 min. This method improves upon manual segmentation by radiologists, which routinely takes several hours.

Temporally aware volumetric generative adversarial network-based MR image reconstruction with simultaneous respiratory motion compensation: Initial feasibility in 3D dynamic cine cardiac MRI

PURPOSE

Develop a novel three-dimensional (3D) generative adversarial network (GAN)-based technique for simultaneous image reconstruction and respiratory motion compensation of 4D MRI. Our goal was to enable high-acceleration factors 10.7X-15.8X, while maintaining robust and diagnostic image quality superior to state-of-the-art self-gating (SG) compressed sensing wavelet (CS-WV) reconstruction at lower acceleration factors 3.5X-7.9X.

METHODS

Our GAN was trained based on pixel-wise content loss functions, adversarial loss function, and a novel data-driven temporal aware loss function to maintain anatomical accuracy and temporal coherence. Besides image reconstruction, our network also performs respiratory motion compensation for free-breathing scans. A novel progressive growing-based strategy was adapted to make the training process possible for the proposed GAN-based structure. The proposed method was developed and thoroughly evaluated qualitatively and quantitatively based on 3D cardiac cine data from 42 patients.

RESULTS

Our proposed method achieved significantly better scores in general image quality and image artifacts at 10.7X-15.8X acceleration than the SG CS-WV approach at 3.5X-7.9X acceleration (4.53 ± 0.540 vs. 3.13 ± 0.681 for general image quality, 4.12 ± 0.429 vs. 2.97 ± 0.434 for image artifacts, P < .05 for both). No spurious anatomical structures were observed in our images. The proposed method enabled similar cardiac-function quantification as conventional SG CS-WV. The proposed method achieved faster central processing unit-based image reconstruction (6 s/cardiac phase) than the SG CS-WV (312 s/cardiac phase).

CONCLUSION

The proposed method showed promising potential for high-resolution (1 mm³ ) free-breathing 4D MR data acquisition with simultaneous respiratory motion compensation and fast reconstruction time.

Case 286: Sarcoidlike Granulomatosis and Lymphadenopathy-Thoracic Manifestations of Nivolumab Drug Toxicity

History A 70-year-old man had a posterior left thigh lesion confirmed to be biopsy-proven melanoma. The patient underwent wide excision and sentinel node biopsy, which showed absence of residual melanoma. Two years later, the patient noticed a subcentimeter subcutaneous lump in his thigh. Repeat excisional biopsy showed involvement of the surrounding soft tissue, consistent with a satellite lesion. Follow-up combined PET/CT revealed satellite nodules around the primary lesion, enabling confirmation of subcutaneous metastatic disease. The patient was subsequently started on nivolumab, an anti-programmed cell death 1 (PD-1) immune checkpoint inhibitor that blocks PD-1 and is approved as a first-line treatment in patients with advanced metastatic melanoma. On the baseline scan prior to starting nivolumab, there were no CT findings that suggested metastatic disease, nor were there enlarged mediastinal or hilar lymph nodes. Five months after initiation of nivolumab treatment, the first follow-up chest CT scan was performed and showed new findings in the mediastinum and bilateral lungs. The patient remained asymptomatic during the treatment period. Furthermore, the subcutaneous metastatic disease remained stable during the treatment period, and no other site of metastatic disease was noted on follow-up CT scans obtained during the first 5 months of treatment. The patient had no prior history of infectious or occupational exposures. During the nivolumab treatment cycle, his pertinent laboratory values and physical examination findings were unremarkable.

Four-dimensional Multiphase Steady-State MRI with Ferumoxytol Enhancement: Early Multicenter Feasibility in Pediatric Congenital Heart Disease

Background The value of MRI in pediatric congenital heart disease (CHD) is well recognized; however, the requirement for expert oversight impedes its widespread use. Four-dimensional (4D) multiphase steady-state imaging with contrast enhancement (MUSIC) is a cardiovascular MRI technique that uses ferumoxytol and captures all anatomic features dynamically. Purpose To evaluate multicenter feasibility of 4D MUSIC MRI in pediatric CHD. Materials and Methods In this prospective study, participants with CHD underwent 4D MUSIC MRI at 3.0 T or 1.5 T between 2014 and 2020. From a pool of 460 total studies, an equal number of MRI studies from three sites (n = 60) was chosen for detailed analysis. With use of a five-point scale, the feasibility of 4D MUSIC was scored on the basis of artifacts, image quality, and diagnostic confidence for intracardiac and vascular connections (n = 780). Respiratory motion suppression was assessed by using the signal intensity profile. Bias between 4D MUSIC and two-dimensional (2D) cine imaging was evaluated by using Bland-Altman analysis; 4D MUSIC examination duration was compared with that of the local standard for CHD. Results A total of 206 participants with CHD underwent MRI at 3.0 T, and 254 participants underwent MRI at 1.5 T. Of the 60 MRI examinations chosen for analysis (20 per site; median participant age, 14.4 months [interquartile range, 2.3-49 months]; 33 female participants), 56 (93%) had good or excellent image quality scores across a spectrum of disease complexity (mean score ± standard deviation: 4.3 ± 0.6 for site 1, 4.9 ± 0.3 for site 2, and 4.6 ± 0.7 for site 3; P < .001). Artifact scores were inversely related to image quality (r = -0.88, P < .001) and respiratory motion suppression (P < .001, r = -0.45). Diagnostic confidence was high or definite in 730 of 780 (94%) intracardiac and vascular connections. The correlation between 4D MUSIC and 2D cine ventricular volumes and ejection fraction was high (range of r = 0.72-0.85; P < .001 for all). Compared with local standard MRI, 4D MUSIC reduced the image acquisition time (44 minutes ± 20 vs 12 minutes ± 3, respectively; P < .001). Conclusion Four-dimensional multiphase steady-state imaging with contrast enhancement MRI in pediatric congenital heart disease was feasible in a multicenter setting, shortened the examination time, and simplified the acquisition protocol, independently of disease complexity. Clinical trial registration no. NCT02752191 © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Roest and Lamb in this issue.

Pulmonary vein and left atrial posterior wall isolation for the treatment of atrial fibrillation: Comparable outcomes for adults with congenital heart disease

INTRODUCTION

Optimal treatment strategies for ACHD with AF are unknown. This study sought to assess outcomes of pulmonary vein isolation (PVI) ± left atrial (LA), posterior wall isolation (PWI) for adults with congenital heart disease (ACHD), and atrial fibrillation (AF).

METHODS

A retrospective review of all cryoballoon (CB) PVI ± PWI procedures at a single center over a 3-year period were performed. Clinical characteristics and outcomes for patients with and without ACHD were compared. The primary outcome was the occurrence of atrial tachyarrhythmia at 12-months postablation after a 90-day blanking period.

RESULTS

Three-hundred and sixteen patients (mean: 63 ± 12 years, [63% male]) underwent CB PVI ± PWI during the study, including 31 (10%) ACHD (simple 35%, moderate 39% complex 26%; nonparoxysmal AF in 52%). ACHD was younger (51 vs. 64 years; p < .001) with a lower CHADS₂ DS₂ -VASc score (1.2 vs. 2.1; p = .001) but had a greater LA diameter (4.9 vs. 4.0 cm; p < .001) and a number of prior cardioversions (0.9 vs. 0.4; p < .001) versus controls. 12-month freedom from recurrent AF was similar for ACHD and controls (76% vs. 80%; p = .6) and remained nonsignificant in multivariate analysis (hazard ratio: 1.8, 95% confidence interval: 0.7-5.1; p = .22). At 12-months postablation, 75% of ACHD versus 93% of control patients were off antiarrhythmic drug therapy (p = .07).

CONCLUSION

This study demonstrates younger age and lower conventional stroke risk, yet clinically advanced AF for ACHD relative to controls. CB PVI ± PWI was an effective strategy for the treatment of AF among all forms of ACHD with similar 12-month outcomes as compared to controls.

CT evaluation of unrepaired/incidental congenital cardiovascular diseases in adults

Congenital heart disease (CHD) affects approximately one million people in the USA with the number increasing by 5% each year. Patients are usually both diagnosed and treated in infancy, however many of them may have subclinical CHD that remains undiagnosed until late adulthood. Patients with complex CHD tend to be symptomatic and are diagnosed at a younger age than those with a single defect. CHDs can be divided into three categories, including cardiac, great vessels and coronary artery anomalies. Recent advances in computed tomography (CT) technology with faster acquisition time and improved spatial resolution allow for detailed evaluation of cardiac morphology and function. The concomitant increased utilization of CT has simultaneously led to more sensitive detection and more thorough diagnosis of CHD. Recognition of and understanding the imaging attributes specific to each anomaly is important for radiologists in order to make a correct and definite diagnosis. This article reviews the spectrum of CHDs, which persist into adulthood that may be encountered by radiologists on CT.

Case 286

History A 70-year-old man had a posterior left thigh lesion confirmed to be biopsy-proven melanoma. The patient underwent wide excision and sentinel node biopsy, which showed absence of residual melanoma. Two years later, the patient noticed a subcentimeter subcutaneous lump in his thigh. Repeat excisional biopsy showed involvement of the surrounding soft tissue, consistent with a satellite lesion. Follow-up combined PET/CT revealed satellite nodules around the primary lesion, enabling confirmation of subcutaneous metastatic disease. The patient was subsequently started on nivolumab, an anti-programmed cell death 1 (PD-1) immune checkpoint inhibitor that blocks PD-1 and is approved as a first-line treatment in patients with advanced metastatic melanoma. On the baseline scan prior to starting nivolumab, there were no CT findings that suggested metastatic disease, nor were there enlarged mediastinal or hilar lymph nodes. Five months after initiation of nivolumab treatment, the first follow-up chest CT scan was performed and showed new findings in the mediastinum (Fig 1) and bilateral lungs (Figs 2, 3). The patient remained asymptomatic during the treatment period. Furthermore, the subcutaneous metastatic disease remained stable during the treatment period, and no other site of metastatic disease was noted on follow-up CT scans obtained during the first 5 months of treatment. The patient had no prior history of infectious or occupational exposures. During the nivolumab treatment cycle, his pertinent laboratory values and physical examination findings were unremarkable.

Chronic airspace disease: Review of the causes and key computed tomography findings

Chronic airspace diseases are commonly encountered by chest, body or general radiologists in everyday practice. Even though there is significant overlap in the imaging findings of different causes of chronic airspace disease, some key clinical, laboratory and imaging findings can be used to guide the radiologist to the correct diagnosis. The goal of this article is to review and compare these features.

Tracheobronchial Tumors: Radiologic-Pathologic Correlation of Tumors and Mimics

Tracheobronchial masses encompass a broad spectrum of entities, ranging from benign and malignant neoplasms to infectious and inflammatory processes. This article reviews the cross-sectional findings of tracheal tumors and tumor-like entities, correlates imaging findings with histologic pathology, and discusses pearls and pitfalls in accurately diagnosing and classifying tracheal tumors and mimics.

Classification of CT pulmonary angiography reports by presence, chronicity, and location of pulmonary embolism with natural language processing

In this paper we describe an efficient tool based on natural language processing for classifying the detail state of pulmonary embolism (PE) recorded in CT pulmonary angiography reports. The classification tasks include: PE present vs. absent, acute PE vs. others, central PE vs. others, and subsegmental PE vs. others. Statistical learning algorithms were trained with features extracted using the NLP tool and gold standard labels obtained via chart review from two radiologists. The areas under the receiver operating characteristic curves (AUC) for the four tasks were 0.998, 0.945, 0.987, and 0.986, respectively. We compared our classifiers with bag-of-words Naive Bayes classifiers, a standard text mining technology, which gave AUC 0.942, 0.765, 0.766, and 0.712, respectively.

Correlation between early direct communication of positive CT pulmonary angiography findings and improved clinical outcomes

BACKGROUND

Despite a general consensus that rapid communication of critical radiology findings from radiologists to referring physicians is imperative, a possible association with superior patient outcomes has not been confirmed. The objective of this study was to evaluate the correlation between early direct communication of CT image findings by radiologists to referring physicians and better clinical outcomes in patients with acute pulmonary embolism (PE).

METHODS

This was a retrospective, single-institution, cohort study that included 796 consecutive patients (February 2006 to March 2010) who had acute PE confirmed by CT pulmonary angiography (CTPA) and whose treatment had not been initiated at the time of CTPA acquisition. The time from CTPA to direct communication of the diagnosis was evaluated for its association with time from CTPA to treatment initiation and with 30-day mortality. Cox regression analysis was performed with inverse probability weighting by propensity scores calculated using 20 potential confounding factors.

RESULTS

In 93.4% of patients whose first treatment was anticoagulation, the referring physicians started treatment after receiving direct notification of the diagnosis from the radiologist. Late communication (&gt; 1.5 h after CTPA; n = 291) was associated with longer time to treatment initiation (adjusted hazard ratio [HR], 0.714; 95% CI, 0.610-0.836; P &lt; .001) and higher all-cause and PE-related 30-day mortality (HR, 1.813; 95% CI, 1.163-2.828; P = .009; and HR, 2.625; 95% CI, 1.362-5.059; P = .004, respectively).

CONCLUSIONS

Delay (&gt; 1.5 h of CTPA acquisition) in direct communication of acute PE diagnosis from radiologists to referring physicians was significantly correlated with a higher risk of delayed treatment initiation and death within 30 days.

Statistical methods for predicting mortality in patients diagnosed with acute pulmonary embolism

RATIONALE AND OBJECTIVES

Risk stratification in pulmonary embolism (PE) guides patient management. The purpose of this study was to develop and test novel mortality risk prediction models for subjects with acute PE diagnosed using computed tomographic pulmonary angiography in a large cohort with comprehensive clinical data.

MATERIALS AND METHODS

Retrospective analyses of 1596 consecutive subjects diagnosed with acute PE from a single, large, urban teaching hospital included two modern statistical methods to predict survival in patients with acute PE. Landmark analysis was used for 90-day mortality. Adaptive least absolute shrinkage and selection operator (aLASSO), a penalization method, was used to select variables important for prediction and to estimate model coefficients. Receiver-operating characteristic analysis was used to evaluate the resulting prediction rules.

RESULTS

Using 30-day all-cause mortality outcome, three of the 16 clinical risk factors (the presence of a known malignancy, coronary artery disease, and increased age) were associated with high risk, while subjects treated with anticoagulation had lower risk. For 90-day landmark mortality, subjects with recent operations had a lower risk for death. Both prediction rules developed using aLASSO performed well compared to standard logistic regression.

CONCLUSIONS

The aLASSO regression approach combined with landmark analysis provides a novel tool for large patient populations and can be applied for clinical risk stratification among subjects diagnosed with acute PE. After positive results on computed tomographic pulmonary angiography, the presence of a known malignancy, coronary artery disease, and advanced age increase 30-day mortality. Additional risk stratification can be simplified with these methods, and future work will place imaging-based prediction of mortality in perspective with other clinical data.

Histopathologic and clinical findings of congenital nephrotic syndrome in Iranian children: a study of two centers

INTRODUCTION

Congenital nephrotic syndrome (CNS), an uncommon form of kidney disease, presents during the first year of life and is a diagnostic and therapeutic challenge for the pediatricians as well as pediatric nephrologists. Our study is the first study of Iranian children with CNS in two pediatric nephrology centers in Tehran, Iran.

MATERIALS AND METHODS

We reviewed medical charts of 30 infants diagnosed with CNS from 1990 to 2005.

RESULTS

There were 15 boys and 15 girls with CNS (mean age, 1.7 months). The presentation of the disease was nephrotic syndrome in 96.6% of the patients. Eighty percent of the patients presented within 3 months of life and 16 in the neonatal period. The Finnish type of CNS was seen in 43.3% and diffuse mesangial sclerosis in 50%. Preterm labor and low birth weight was seen in 20%. A family history of nephrotic syndrome in infancy was noted for 8 children (26.7%). Numerous complications of nephrotic syndrome occurred in 73.3%. Seventy percent of the patients had 27 episodes of infections. Sepsis was seen in 43.3% of the children, of which 61.5% were caused by gram-negative bacteria and 38.6% were caused by Staphylococcus aureus. Thrombotic complications and hypertension developed in 6.6% and 23.3% of the patients, respectively. The mortality rate of patients was 86.6%.

CONCLUSIONS

Diffuse mesangial sclerosis is an important cause of CNS. The outcome of our patients was poor and most of our patients died before reaching the age of 5 years old.

Subjective assessment of right ventricle enlargement from computed tomography pulmonary angiography images

To retrospectively evaluate prognostic accuracy of subjective assessment of right ventricle (RV) enlargement on CT pulmonary angiography (CTPA) images in comparison with objective measures of RV enlargement in patients with acute pulmonary embolism (PE). For 200 consecutive patients with acute PE, two readers blinded to patient outcomes subjectively determined whether the maximum RV diameter was greater than that of the left ventricle (LV) using axial CTPA images. For the objective measurements, RV/LV diameter ratios were calculated using axial images and 4-chamber reformatted images. For all assessments, sensitivities and specificities for predicting PE-related death within 30-days and a composite outcome including PE-related death or the need for intensive therapies were compared. The agreement between two readers was 91.5% (kappa = 0.83) and all other assessments had pair-wise agreement over 75% (kappa = 0.53-0.72). There was no significant difference in sensitivity between the subjective and objective methods for predicting both outcomes. The specificity for subjective RV enlargement (55.4-67.7%) was significantly higher than objective measures (45.8-53.1%), except for the 4-chamber views where, for one reader, the specificity of the subjective evaluation was higher but did not reach statistical significance. Complex measurements of RV/LV diameter ratios may not be needed to maximize the prognostic value from CTPA. The radiologist who interprets the CTPA images should report RV enlargement when the RV diameter subjectively appears larger than the LV.

Leech endoparasitism: report of a case and review of the literature

We report the case of an 11-year-old boy who presented with fresh blood in his mouth and a history of sore throat during the past 2 weeks that was unresponsive to antibiotic therapy. Inspection of the oral cavity revealed a black circular mass attached to the posterior wall of the oropharynx. This mass was determined to be a live engorged leech. Leech endoparasitism is caused by aquatic leeches that attach themselves to mucus membranes of body cavities after the host has swum in bodies of fresh water or drunk from unsafe water sources. Pharyngeal hirudiniasis may present in different forms depending on the exact location of the parasite in the body and must be included in the list of differential diagnosis for common conditions such as pharyngitis, hemoptysis or anemia in pediatric patients living in endemic areas.

Urine macrophage migration inhibitory factor in pediatric systemic lupus erythematosus

We reported a series of ten patients with lupus nephritis (five patients in the relapse phase and five in the remission phase) and measured the macrophage migration inhibitory factor (MIF), an important pro-inflammatory cytokine with probable role in the pathogenesis of many inflammatory diseases, in their urine samples. MIF/creatinine (Cr) ratio directly correlated with disease activity and it does not have any significant difference between inactive disease and normal ones. We found that the urine MIF/Cr ratio not only differentiates active disease from inactive disease and normal ones but also correlates with the activity indices of renal pathology.