Quantitative Measurement on Contrast-Enhanced CT Distinguishes Small Clear Cell Renal Cell Carcinoma From Benign Renal Tumors: A Multicenter Study

RATIONALE AND OBJECTIVES

To evaluate the potential of quantitative measurements on contrast-enhanced CT (CECT) in differentiating small (≤4 cm) clear cell renal cell carcinoma (ccRCC) from benign renal tumors, including fat-poor angiomyolipoma (fpAML) and renal oncocytoma (RO).

MATERIALS AND METHODS

244 patients with pathologically confirmed ccRCC (n = 184) and benign renal tumors (fpAML, n = 50; RO, n = 10) were randomly assigned into training cohort (n = 193) and test cohort 1 (n = 51), while external test cohort 2 (n = 50) was from another hospital. Quantitative parameters were obtained from CECT (unenhanced phase, UP; corticomedullary phase, CMP; nephrographic phase, NP; excretory phase, EP) by measuring attenuation of renal mass and cortex and subsequently calculated. Univariable and multivariable logistic regression analyses were performed to evaluate the association between these parameters and ccRCC. Finally, the constructed models were compared with radiologists' diagnoses.

RESULTS

In univariable analysis, UP-related parameters, particularly UPC-T (cortex minus tumor attenuation on UP), demonstrated AUC of 0.766 in training cohort, 0.901 in test cohort 1, 0.805 in test cohort 2. The heterogeneity-related parameter SD (standard deviation) showed AUC of 0.781, 0.834, and 0.875 respectively. In multivariable analysis, model 1 incorporating UPC-T, NPC-T (cortex minus tumor attenuation on NP), CMPT-UPT (tumor attenuation on CMP minus UP), and SD yielded AUC of 0.866, 0.923, and 0.949 respectively. When compared with radiologists, multivariate models demonstrated higher accuracy (0.800-0.860) and sensitivity (0.794-0.971) than radiologists' assessments (accuracy: 0.700-0.720, sensitivity: 0.588-0.706).

CONCLUSION

Quantitative measurements on CECT, particularly UP- and heterogeneity-related parameters, have potential to discriminate ccRCC and benign renal tumors (fpAML, RO).

Unenhanced Breast MRI With Diffusion-Weighted Imaging for Breast Cancer Detection: Effects of Training on Performance and Agreement of Subspecialty Radiologists

OBJECTIVE

To investigate whether reader training improves the performance and agreement of radiologists in interpreting unenhanced breast magnetic resonance imaging (MRI) scans using diffusion-weighted imaging (DWI).

MATERIALS AND METHODS

A study of 96 breasts (35 cancers, 24 benign, and 37 negative) in 48 asymptomatic women was performed between June 2019 and October 2020. High-resolution DWI with b-values of 0, 800, and 1200 sec/mm² was performed using a 3.0-T system. Sixteen breast radiologists independently reviewed the DWI, apparent diffusion coefficient maps, and T1-weighted MRI scans and recorded the Breast Imaging Reporting and Data System (BI-RADS) category for each breast. After a 2-h training session and a 5-month washout period, they re-evaluated the BI-RADS categories. A BI-RADS category of 4 (lesions with at least two suspicious criteria) or 5 (more than two suspicious criteria) was considered positive. The per-breast diagnostic performance of each reader was compared between the first and second reviews. Inter-reader agreement was evaluated using a multi-rater κ analysis and intraclass correlation coefficient (ICC).

RESULTS

Before training, the mean sensitivity, specificity, and accuracy of the 16 readers were 70.7% (95% confidence interval [CI]: 59.4-79.9), 90.8% (95% CI: 85.6-94.2), and 83.5% (95% CI: 78.6-87.4), respectively. After training, significant improvements in specificity (95.2%; 95% CI: 90.8-97.5; P = 0.001) and accuracy (85.9%; 95% CI: 80.9-89.8; P = 0.01) were observed, but no difference in sensitivity (69.8%; 95% CI: 58.1-79.4; P = 0.58) was observed. Regarding inter-reader agreement, the κ values were 0.57 (95% CI: 0.52-0.63) before training and 0.68 (95% CI: 0.62-0.74) after training, with a difference of 0.11 (95% CI: 0.02-0.18; P = 0.01). The ICC was 0.73 (95% CI: 0.69-0.74) before training and 0.79 (95% CI: 0.76-0.80) after training (P = 0.002).

CONCLUSION

Brief reader training improved the performance and agreement of interpretations by breast radiologists using unenhanced MRI with DWI.

Autopsy findings of acute erythroid leukemia

Acute erythroid leukemia (AEL) is an exceedingly uncommon but distinct hematological malignancy that shows neoplastic proliferation of erythroid precursors with maturation arrest and no significant myeloblasts. We describe an autopsy case of this rare entity in a 62-year-old man with co-morbidities. He underwent a bone marrow (BM) examination for pancytopenia during the first outpatient department visit, which revealed an increased number of erythroid precursors with dysmegakaryopoiesis suggesting the possibility of Myelodysplastic syndromes (MDS). Thereafter, his cytopenia got worsened, warranting blood and platelet transfusions. Four weeks later on the second BM examination, AEL was diagnosed based on morphology and immunophenotyping. Targeted resequencing for myeloid mutations revealed TP53 and DNMT3A mutations. He was initially managed along febrile neutropenia with the stepwise escalation of antibiotics. He developed hypoxia attributed to anemic heart failure. Subsequently, he had hypotension and respiratory fatigue pre-terminally and succumbed to his Illness. A complete autopsy showed infiltration of various organs by AEL and leukostasis. Besides, there was extramedullary hematopoiesis, arterionephrosclerosis, diabetic nephropathy (ISN-RPS class II), mixed dust pneumoconiosis, and pulmonary arteriopathy. The histomorphology of AEL was challenging, and the differential diagnoses were many. Thus, this case highlights the autopsy pathology of AEL, an uncommon entity with a strict definition, and its relevant differentials.

Albumin, filamin-A and cytokeratin 19 help distinguish intrahepatic cholangiocarcinoma from extrahepatic adenocarcinoma

BACKGROUND

The differential diagnosis of intrahepatic cholangiocarcinomas (iCCAs) from metastatic adenocarcinomas from organs adjacent to the liver (gallbladder, pancreas, and stomach) is difficult due to histopathological similarity and a lack of specific markers. This study aimed to develop a method to differentiate iCCA and adenocarcinomas originated from extrahepatic organs adjacent to the liver.

METHODS

We retrospectively enrolled surgically resected iCCA (n = 181) and adenocarcinomas from extrahepatic organs (n = 30, n = 28, and n = 38 from gallbladder, pancreas, and stomach, respectively) between 2007 and 2013. The albumin mRNA in situ hybridization (ISH) and immunohistochemistry (IHC) of filamin-A and cytokeratin 19 (CK19) were performed using tissue microarray. Using logistic regression analysis of three markers, iCCA-score was developed, and its diagnostic performance was evaluated.

RESULTS

The iCCAs were more frequently positive for albumin ISH (23.2% vs. 0%), filamin-A IHC (47.5% vs. 12.5%) and CK19 (68.5% vs. 40.6%) than extrahepatic adenocarcinomas (p < 0.001 for all). The iCCA-score consisting of these three markers was developed, and it showed higher diagnostic performance (area under the curve [AUC], 0.798 vs. 0.616, p < 0.001). Taking an iCCA-score of 2 or higher as the threshold for iCCA, the sensitivity was substantially higher than albumin ISH alone (45.9% and 23.2%, respectively; p < 0.001), but maintained high specificity (94.8% and 100%, respectively).

CONCLUSION

Albumin ISH and IHC staining for filamin-A and CK19 showed distinct expression patterns between iCCA and extrahepatic adenocarcinomas from gallbladder, pancreas, and stomach. We developed iCCA-score that consisted of those three markers, and it showed better diagnostic performance than albumin ISH alone.

Diagnosis of Active Pulmonary Tuberculosis and Community Acquired Pneumonia Using Convolution Neural Network Based on Transfer Learning

RATIONALE AND OBJECTIVES

A convolutional neural network (CNN) model for the diagnosis of active pulmonary tuberculosis (APTB) and community-acquired pneumonia (CAP) using chest radiographs (CRs) was constructed and verified based on transfer learning.

MATERIALS AND METHODS

CRs of 1247 APTB cases, 1488 CAP cases and 1247 normal cases were collected. All CRs were randomly divided into training set (1992 cases), validation set (1194 cases) and test set (796 cases) by stratified sampling in 5:3:2 radio. After normalization of CRs, the convolution base of pre-trained CNN (VGG16) model on ImageNet dataset was used to extract features, and the grid search was used to determine the optimal classifier module, which was added to the convolution base for transfer learning. After the training, the model with the highest accuracy of the validation set was selected as the optimal model to verify in the test set and calculate the accuracy of the model.

RESULTS

The accuracy of validation set in the 63rd epochs was the highest, which was 0.9430, and the corresponding Categorical crossentropy was 0.1742. The accuracy of the training set was 0.9428, and the Categorical crossentropy was 0.1545. When the optimal model was applied to the test set, the accuracy was 0.9447, and the Categorical crossentropy was 0.1929.

CONCLUSION

The transfer learning-based CNN model has good classification performance in the diagnosis of APTB, CAP and normal patients using CRs.

Assessment of breast lesions by the Kaiser score for differential diagnosis on MRI: the added value of ADC and machine learning modeling

OBJECTIVES

To evaluate the diagnostic performance of Kaiser score (KS) adjusted with the apparent diffusion coefficient (ADC) (KS+) and machine learning (ML) modeling.

METHODS

A dataset of 402 malignant and 257 benign lesions was identified. Two radiologists assigned the KS. If a lesion with KS > 4 had ADC > 1.4 × 10^-3 mm²/s, the KS was reduced by 4 to become KS+. In order to consider the full spectrum of ADC as a continuous variable, the KS and ADC values were used to train diagnostic models using 5 ML algorithms. The performance was evaluated using the ROC analysis, compared by the DeLong test. The sensitivity, specificity, and accuracy achieved using the threshold of KS > 4, KS+ > 4, and ADC ≤ 1.4 × 10^-3 mm²/s were obtained and compared by the McNemar test.

RESULTS

The ROC curves of KS, KS+, and all ML models had comparable AUC in the range of 0.883-0.921, significantly higher than that of ADC (0.837, p < 0.0001). The KS had sensitivity = 97.3% and specificity = 59.1%; and the KS+ had sensitivity = 95.5% with significantly improved specificity to 68.5% (p < 0.0001). However, when setting at the same sensitivity of 97.3%, KS+ could not improve specificity. In ML analysis, the logistic regression model had the best performance. At sensitivity = 97.3% and specificity = 65.3%, i.e., compared to KS, 16 false-positives may be avoided without affecting true cancer diagnosis (p = 0.0015).

CONCLUSION

Using dichotomized ADC to modify KS to KS+ can improve specificity, but at the price of lowered sensitivity. Machine learning algorithms may be applied to consider the ADC as a continuous variable to build more accurate diagnostic models.

KEY POINTS

• When using ADC to modify the Kaiser score to KS+, the diagnostic specificity according to the results of two independent readers was improved by 9.4-9.7%, at the price of slightly degraded sensitivity by 1.5-1.8%, and overall had improved accuracy by 2.6-2.9%. • When the KS and the continuous ADC values were combined to train models by machine learning algorithms, the diagnostic specificity achieved by the logistic regression model could be significantly improved from 59.1 to 65.3% (p = 0.0015), while maintaining at the high sensitivity of KS = 97.3%, and thus, the results demonstrated the potential of ML modeling to further evaluate the contribution of ADC. • When setting the sensitivity at the same levels, the modified KS+ and the original KS have comparable specificity; therefore, KS+ with consideration of ADC may not offer much practical help, and the original KS without ADC remains as an excellent robust diagnostic method.

Renal angiomyolipoma with epithelial cyst

Angiomyolipoma with epithelial cysts (AMLEC) is a recently described entity and is an uncommon subtype of kidney angiomyolipomas. AMLEC is a benign entity but usually masquerades a renal cell carcinoma on imaging examination. AMLEC has a distinct histological and immunohistochemical staining pattern, which helps in the pathological diagnosis. We present a rare case of AMLEC in a 26-year-old female, which was provisionally diagnosed as renal cell carcinoma on radiology. We also summarize the differential diagnosis of this rare variant, its characteristic features, and a review of the literature.

The round window sign: a sensitive sign to detect perilymphatic fistulae on delayed postcontrast 3D-FLAIR sequence

OBJECTIVES

The aim of this study is to assess the diagnostic performance of a new MR sign, named the round window sign (RWS), to diagnose perilymphatic fistula (PLF) in a population of patients with chronic cochleo-vestibular symptoms, classified as definite or probable Menière's disease (MD).

METHODS

A total of 164 patients (mean age 52 ± 35 years) with chronic cochleo-vestibular symptoms underwent MRI, between 4 and 5 h after intravenous gadoteric acid injection (Dotarem®, 0.1 mmol/kg). MRI exploration was carried out on a 3-T Achieva® TX scanner. We analyzed the presence of the RWS, defined as a nodular FLAIR high signal in the round window (RW) and the presence of associated saccular hydrops. When this RWS was present, a temporal bone CT scan was performed and the RW was analyzed.

RESULTS

Of the 164 patients with definite MD (85 patients) or probable MD (79 patients), we found the RWS in 18 (11%), and 17/18 were classified into the group of probable MD. All these 18 patients showed other MR sequences considered as normal, including heavily weighted T2 imaging. Among these 18 patients, the temporal bone CT examination presented a filling of the RW in 13 patients (72%) and no filling of the RW in 5 patients (28%). Seven patients were surgically managed confirming in vivo the PLF diagnosis. The RWS was associated with the presence of a saccular hydrops in 4 cases.

CONCLUSION

Delayed postcontrast 3D-FLAIR may reveal perilymphatic fistulae in patients with probable Menière's disease using the round window sign.

KEY POINTS

• MRI with delayed acquisition can detect perilymphatic fistulae with perfect sensitivity, based on the presence of the round window sign. • This visual sign is only visible on a 3D-FLAIR sequence. • 3D-FLAIR sequence with delayed acquisition is more sensitive than temporal bone CT scan examination in detecting PLF.

Diagnostic considerations in central odontogenic fibroma of the maxilla: 2 case reports

Central odontogenic fibroma (COF) is defined as a fibroblastic odontogenic tumor characterized by varying density of the tooth epithelium. It is an extremely rare benign neoplasm that occurs in the maxilla and the mandible; only a few reports of COF are available in the literature. Diagnosis of the lesion based only on the radiological features of COF is difficult due to variation in the findings regarding this condition. This report describes 2 clinical cases of middle-aged women with COF. Clinical examination revealed palatal mucosal depression; additionally, oral examination, as well as panoramic radiographs, intraoral radiographs, and computed tomography scans, revealed severe root resorption. This report highlights the clinical and radiological imaging features of COF, with the goal of enabling straightforward differential diagnosis of the lesion by the clinician and thereby appropriate treatment of the patient.

[Sinus Tachycardia in the Adolescent: The Importance of Differential Diagnosis]

Sinus tachycardia is common in pediatric age, and is usually related to benign physiological conditions, such as somatoform disorders. Nevertheless, it can also be a presenting sign of a disease with an ominous prognosis. We present a case of a previously healthy 15-year-old girl, admitted for syncope. She had been well until one week before admission, when thoracic pain developed. One month prior to the admission she had started oral contraceptives. On examination, she had persistent sinus tachycardia, despite hemodynamic stability and no other associated sign or symptom. Thoracic computed tomography angiography revealed thrombi in the main pulmonary arteries, which confirmed bilateral pulmonary embolism. She was started on anticoagulation with unremarkable clinical course evolution. Pediatric pulmonary embolism is rare, although probably underdiagnosed, given the nonspecific presentation in most cases. Maintaining a high level of clinical suspicion of pulmonary embolism avoids delay in the diagnosis, allows early appropriate treatment and improves prognosis.

The Role of Ultrasonography in Patients Referring to the Emergency Department with Acute Abdominal Pain

CONTEXT

Acute abdominal pain is a common clinical problem in emergency and non-emergency cases accounting for 5 to 10% of all referrals to the emergency department. Studies have indicated that these widely differentiated diagnoses are common to these complaints. Considering the high prevalence of this complaint in the patients and the wide range of its differential diagnosis, this review study was designed and evaluated aiming at investigating the causes of acute abdominal pain with a focus on assessing the position of ultrasound as a diagnostic tool in the emergency department.

EVIDENCE ACQUISITION

This article was conducted as a narrative review of selected articles from 2005 through 2019. By comparing them, a comprehensive review of ultrasound role was conducted in patients with acute abdominal pain referring to the emergency department.

RESULTS

In this review study, we attempted to use the articles of the clinical approach, the required laboratory tests, the disadvantages and advantages of each imaging technique, the differential diagnosis for acute abdominal pain according to the location of the pain, and the position of ultrasound as a diagnostic aid tool. Eventually, the proposed protrusion will be considered in dealing with a patient with acute abdominal pain.

CONCLUSION

Regarding the wide range of causes providing multiple differential diagnosis, as well as the limited time of the health team in the emergency department for diagnostic and therapeutic measures, particularly in time-sensitive clinical conditions, ultrasound offered by emergency medicine specialists as a diagnostic aid is considered to improve the overall diagnosis and treatment of patients, thereby reducing complications.

Infant acute myocarditis mimicking acute myocardial infarction

Myocarditis is an inflammatory disease of the myocardium with heterogeneous clinical manifestations and progression. In clinical practice, although there are many methods of diagnosis of acute myocarditis, the diagnosis remains an embarrassing dilemma for clinicians. The authors report the case of 9-month-old infant who was brought to the Pediatric Emergency Department with sudden onset dyspnea. Examination disclosed heart failure and resuscitation was undertaken. The electrocardiogram showed an ST segment elevation in the anterolateral leads with a mirror image. Cardiac enzyme tests revealed a significant elevation of troponin and creatine phosphokinase levels. A diagnosis of acute myocardial infarction was made, and heparin therapy was prescribed. The infant died on the third day after admission with cardiogenic shock. The autopsy showed dilatation of the ventricles and massive edema of the lungs. Histological examinations of myocardium samples revealed the presence of a marked lymphocytic infiltrate dissociating myocardiocytes. Death was attributed to acute myocarditis. The authors call attention to the difficulties of differential diagnosis between acute myocarditis and acute myocardial infarction especially in children, and to the important therapeutic implications of a correct diagnosis.

Mean Corpuscular Volume and Mortality in Patients with CKD

BACKGROUND AND OBJECTIVES

Mean corpuscular volume is the measure of the average size of the circulatory erythrocyte, and it is principally used as an index for the differential diagnosis of anemia. Recently, mean corpuscular volume has been associated with mortality in many clinical settings. However, the association of mean corpuscular volume with mortality in patients with CKD has not been fully addressed.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We conducted a retrospective observational cohort study of 1439 patients with stages 3-5 CKD and baseline mean corpuscular volume values from 2004 to 2012 in a medical center. The study cohort was divided into the high-mean corpuscular volume group and the low-mean corpuscular volume group by the median value (90.8 fl) of mean corpuscular volume. The baseline patient information included demographic data, laboratory parameters, medications, and comorbid conditions. The independent association of mean corpuscular volume with mortality was examined using multivariate Cox regression analysis.

RESULTS

Of the 1439 participants, 234 patients (16.2%) died during a median follow-up of 1.9 years (interquartile range, 1.1-3.8 years). The crude overall mortality rate was significantly higher in the high-mean corpuscular volume group (high-mean corpuscular volume group, 22.7%; low-mean corpuscular volume group, 9.7%; P<0.001). In the fully adjusted models, the high-mean corpuscular volume group was associated with higher risks of all-cause mortality (hazard ratio, 2.19; 95% confidence interval, 1.62 to 2.96; P<0.001), cardiovascular mortality (hazard ratio, 3.57; 95% confidence interval, 1.80 to 7.06; P<0.001), and infection-related mortality (hazard ratio, 2.22; 95% confidence interval, 1.41 to 3.49; P=0.001) compared with the low-mean corpuscular volume group.

CONCLUSIONS

In patients with stages 3-5 CKD, mean corpuscular volume was associated with all-cause mortality, cardiovascular disease mortality, and infection-associated mortality, independent of other factors. The underlying pathophysiologic mechanisms warrant additional investigation.

Application of a Novel Diagnostic Rule in the Differential Diagnosis between Acute Gouty Arthritis and Septic Arthritis

Septic arthritis and gout are major diseases that should be suspected in patients with acute monoarthritis. These two diseases are clinically similar and often indistinguishable without the help of synovial fluid analysis. Recently, a novel diagnostic rule for gout without synovial fluid analysis was developed and showed relevant performances. This study aimed to determine whether this diagnostic rule could perform well in distinguishing gout from septic arthritis. The diagnostic rule comprises 7 clinical and laboratory variables, each of which is given a specified score. The probability of gout is classified into 3 groups according to the sum of the scores: high (≥ 8), intermediate (> 4 to < 8) and low probability (≤ 4). In this retrospective study, we applied this diagnostic rule to 136 patients who presented as acute monoarthritis and were subsequently diagnosed as acute gout (n = 82) and septic arthritis (n = 54) based on synovial fluid analysis. The mean sum of scores of acute gout patients was significantly higher than that of those with septic arthritis (8.6 ± 0.2 vs. 3.6 ± 0.32, P < 0.001). Patients with acute gout had significantly more 'high', and less 'low' probabilities compared to those with septic arthritis (Eta[η]: 0.776). The prevalence of acute gouty arthritis, as confirmed by the presence of monosodium crystal, was 95.5% (61/64), 57.5% (19/33), and 5.1% (2/39) in high, intermediate and low probability group, respectively. The recently introduced diagnostic rule properly discriminates acute gout from septic arthritis. It may help physicians diagnose gout in cases difficult to be differentiated from septic arthritis.

Comparison of Memory Function and MMPI-2 Profile between Post-traumatic Stress Disorder and Adjustment Disorder after a Traffic Accident

OBJECTIVE

Differential diagnosis between post-traumatic stress disorder (PTSD) and adjustment disorder (AD) is rather difficult, but very important to the assignment of appropriate treatment and prognosis. This study investigated methods to differentiate PTSD and AD.

METHODS

Twenty-five people with PTSD and 24 people with AD were recruited. Memory tests, the Minnesota Multiphasic Personality Inventory 2 (MMPI-2), and Beck's Depression Inventory were administered.

RESULTS

There were significant decreases in immediate verbal recall and delayed verbal recognition in the participants with PTSD. The reduced memory functions of participants with PTSD were significantly influenced by depressive symptoms. Hypochondriasis, hysteria, psychopathic deviate, paranoia, schizophrenia, post-traumatic stress disorder scale of MMPI-2 classified significantly PTSD and AD group.

CONCLUSION

Our results suggest that verbal memory assessments and the MMPI-2 could be useful for discriminating between PTSD and AD.

Community-acquired methicillin-resistant Staphylococcus aureus: a potential diagnosis for a 16-year-old athlete with knee pain

OBJECTIVE

This case report aims to raise awareness in chiropractic physicians of the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in adolescents who participate in sports activities and to alert the chiropractic physician of the necessity to consider potential diagnoses that are not within their typical clinical heuristic.

CLINICAL FEATURES

A 16-year-old adolescent girl entered the clinic with a complaint of left knee pain that had an insidious onset during her involvement in sports activities. Later that same day, her knee became enlarged, red, and had pustular formations with a discharge. She was taken to an urgent care facility and subsequently diagnosed with MRSA. Her history included treatment of a left knee musculoskeletal condition 6 weeks prior to which she had responded favorably.

INTERVENTIONS AND OUTCOMES

She was treated medically with an aggressive course of antibiotic therapy and excision of the furuncle. The chiropractic physician played a role in patient education and notifying local school authorities of the case.

CONCLUSION

Doctors of chiropractic must prepare themselves for the unexpected and remain open to diagnostic possibilities outside of the normal scope of practice. Knee pain or cellulitis of any type may require additional diagnostic and patient care protocols to make the correct diagnosis. With the incidence of community-acquired MRSA increasing at an alarming rate, it is certainly a diagnosis doctors of chiropractic should be aware of when treating patients, especially those involved in sports activities.