Diagnostic Utility of Restriction Spectrum Imaging in Head and Neck Tumors: A Pilot Study.

OBJECTIVE: Imaging is crucial in the assessment of head and neck cancers for site, extension, and enlarged lymph nodes. Restriction spectrum imaging (RSI) is a new diffusion-weighted magnetic resonance imaging (MRI) technique that enhances the ability to differentiate aggressive cancer from low-grade or benign tumors and helps guide treatment and biopsy. Its contribution to imaging of brain and prostate tumors has been previously published. However, there are no prior studies using RSI sequence in head and neck tumors. The purpose of this study was to evaluate the feasibility of performing RSI in head and neck cancer. METHODS: An additional RSI sequence was added in the routine MRI neck protocol for 13 patients diagnosed with head and neck cancer between November 2018 and April 2019. Restriction spectrum imaging sequence was performed with b values of 0, 500, 1500, and 3000 s/mm 2 and 29 directions on 1.5T magnetic resonance scanners.Diffusion-weighted imaging (DWI) images and RSI images were compared according to their ability to detect the primary malignancy and possible metastatic lymph nodes. RESULTS: In 71% of the patients, RSI outperformed DWI in detecting the primary malignancy and possible metastatic lymph nodes, whereas in the remaining cases, the 2 were comparable. In 66% of the patients, RSI detected malignant lymph nodes that DWI/apparent diffusion coefficient failed to detect. CONCLUSIONS: This is the first study of RSI in head and neck imaging and showed its superiority over the conventional DWI sequence. Because of its ability to differentiate benign and malignant lymph nodes in some cases, the addition of RSI to routine head and neck MRI should be considered.

COVID-19 S: A new proposal for diagnosis and structured reporting of COVID-19 on computed tomography imaging.

PURPOSE: Because of the widespread use of CT in the diagnosis of COVID 19, indeterminate presentations such as single, few or unilateral lesions amount to a considerable number. We aimed to develop a new classification and structured reporting system on CT imaging (COVID-19 S) that would facilitate the diagnosis of COVID-19 in the most accurate way. METHODS: Our retrospective cohort included 803 patients with a chest CT scan upon suspicion of COVID 19. The patients' history, physical examination, CT findings, RT PCR, and other laboratory test results were reviewed, and a final diagnosis was made as COVID 19 or non-COVID 19. Chest CT scans were classified according to the COVID 19 S CT diagnosis criteria. Cohen's kappa analysis was used. RESULTS: Final clinical diagnosis was COVID-19 in 98 patients (12%). According to the COVID-19 S CT diagnosis criteria, the number of patients in the normal, compatible with COVID 19, indeterminate and alternative diagnosis groups were 581 (72.3%), 97 (12.1%), 16 (2.0%) and 109 (13.6%). When the indeterminate group was combined with the group compatible with COVID 19, the sensitivity and specificity of COVID-19 S were 99.0% and 87.1%, with 85.8% positive predictive value (PPV) and 99.1% negative predictive value (NPV). When the indeterminate group was combined with the alternative diagnosis group, the sensitivity and specificity of COVID-19 S were 93.9% and 96.0%, with 94.8% PPV and 95.2% NPV. CONCLUSION: COVID-19 S CT classification system may meet the needs of radiologists in distinguishing COVID-19 from pneumonia of other etiologies and help optimize patient management and disease control in this pandemic by the use of structured reporting.

A heart atlas for breast radiation therapy and the influence of delination education on both intra and interobserver variability.

PURPOSE: We developed a heart atlas for breast radiation therapy and evaluated the influence of education on intra and inter-observer similarity, and cardiac dose reporting. MATERIALS AND METHODS: The data of 16 left breast cancer patients were analyzed. Eight observers delineated heart and cardiac subunits [left (LCA) and right (RCA) coronary arteries, left anterior descending artery (LAD), bilateral atrium and ventricles] before the education. A radiologist and radiation oncologist developed the atlas and delineated the gold standard (GS) volumes. Observers repeated the delineation after education. RT plans were made for pre/post-atlas contours. The similarity was assessed by Dice (DSC) and Jaccard (JSC) similarity coefficient indices. The absolute difference rate was calculated for the dose analysis. RESULTS: The inter-observer similarity increased in heart and all subunits. The intra-observer similarity showed a heterogeneous distribution. The absolute difference rate in dose reporting was statistically significant for the bilateral atrium, right ventricle, LAD, LCA + LAD, RCA's maximum doses (p < 0.05). The maximum dose reporting differences from the GS decreased from 16.9 to 8.9% for LAD (p = 0.011); from 14.8 to 9.3% for LCA + LAD (p = 0.010). CONCLUSION: The cardiac atlas reduces the intra-interobserver differences and improves dose reporting consistency. The first intra-observer similarity analysis was made in our study and revealed the need for repeated education to increase the consistency.

Utility of chest CT after a chest X-ray in patients presenting to the ED with non-traumatic thoracic emergencies.

BACKGROUND: Chest radiography is the initial choice for thoracic imaging. However, the wide availability of computed tomography (CT) has led to a substantial increase in its use in the emergency department (ED). We evaluated the utility of chest CT after a chest X-ray in patients presenting to the ED with non-traumatic thoracic emergencies, and determined if the diagnosis and management decision changed after CT. METHODS: The study enrolled 500 consecutive patients with both chest X-rays and CT who presented to the ED with non-traumatic complaints. Chest X-rays and CT images obtained within 12h before any definitive treatment were randomly evaluated in consensus by two radiologists blinded to the clinical information. RESULTS: The chest X-ray and CT image findings were concordant in 49.2% of the 500 patients and this concordance was negatively correlated with patient age. Leading diagnosis and management decisions based on the chest radiograph changed after CT in 35.4% of the study group and this finding was also correlated with age. In 55% of 205 patients, pneumonic infiltrations were undiagnosed with radiography. Pulmonary edema was the most specific (93.3%) and sensitive (85.4%) radiography finding. Posteroanterior chest radiographs taken in the upright position had higher concordance with CT than anteroposterior (AP) radiographs taken in the supine position. CONCLUSIONS: Chest CT may be an appropriate imaging choice in patients presenting to the ED for non-traumatic reasons, particularly for elderly patients and when the radiograph is taken with the AP technique in a supine position.

A case of concomitant intralobar bronchopulmonary sequestration and situs inversus totalis.

BACKGROUND AND AIMS: Situs inversus is a rare congenital abnormality involving partial or complete transposition of the thoracic or abdominal viscera. In situs inversus totalis, both the thoracic and abdominal viscera are transposed. The incidence of this condition is 0.01% to 0.02%. Bronchopulmonary sequestration (BPS) is a rare congenital abnormality of the respiratory tract with an incidence of 0.15% to 1.80%. Intralobar sequestration is uncommonly associated with congenital anomalies. METHODS: A routine chest X-ray of a 41-year-old asymptomatic man showed dextrocardia, a left-sided liver, right-sided stomach, and left paracardiac opacity. RESULTS: Computed tomography (CT) and CT pulmonary angiography revealed dextrocardia with situs inversus totalis and left paracardiac intralobar BPS in the lingular segment of the left upper lobe. CONCLUSION: We present a rare case of combined situs inversus totalis and intralobar BPS with an atypical location and feeder artery.

Role of mass effect, tumor volume and peritumoral edema volume in the differential diagnosis of primary brain tumor and metastasis.

INTRODUCTION: The differentiation of metastatic and primary brain tumors with certainty is important since clinical management and treatment of these two types of tumors are radically different. The purpose of the present study was to evaluate the effect of peritumoral edema volume, tumor volume and mass effect of tumor on differential diagnosis of metastatic and primary brain tumors. Also we have planned to investigate if the relationship between edema volume and mass affect can contribute to the differential diagnosis. MATERIAL AND METHODS: We retrospectively reviewed MR images of patients with primary (n=40) and metastatic (n=40) intra-axial supratentorial brain tumor. Supratentorial primary solitary brain tumor group was also subdivided as GBM subgroup (n=24) and other than GBM subgroup (n=16) for statistical analysis. Metastasis at suitable localization which can lead to midline shift (due to mass effect) were selected. Tumor volume, peritumoral edema volume and mass-edema index (peritumoral edema volume/tumor volume) were calculated. Displacement of the midline structures (subfalcian herniation) was measured. Metastasis, GBM and other than GBM groups were evaluated for subfalcian shift, shift grade, tumor volume, peritumoral edema volume and mass-edema index by using Kruskal-Wallis test after Bonferroni correction. Mann-Whitney U test was used to analise subfalcian shift, tumor volume, peritumoral edema volume and mass-edema index of primary tumor and methastasis groups since the data was not normally distributed. Shift grade of the two groups was analised with chi-square test. RESULTS: Midline shift, tumor volume and mass-edema index were significantly different between metastasis and primary tumor groups (p=0.001, p<0.001, p=0.001 respectively). Midline shift and tumor volume of the primary tumor group were greater than metastasis group while mass-edema index was less. Shift grade of metastasis and primary tumor groups was also significant (p=0.041). A midline shift more than 5mm (grade 2) was more common in primary tumors. There was no significant difference between GBM and other than GBM groups. CONCLUSION: Measurement of midline shift, tumor volume and mass-edema index may contribute to the differential diagnosis of brain metastasis from primary brain tumors. Also mass-edema index can be a useful tool for differential diagnosis in the future. But further studies with larger series are needed.

Unusual case of spinal epidermoid cyst and a concomitant spinal arachnoid cyst.

A 38-year-old woman presented with a 12-month history of subjective weakness and pain in her legs. Thoracolumbar MRI revealed two spinal intradural cystic lesions at T5-6 and T11 levels, respectively. The lesion located at the T5-6 level was heterogeneously hyperintense on T2-weighted images and heterogeneously hypointense on T1-weighted images. This lesion showed high signal intensity on diffusion weighted MRI (DWI) and low signal intensity on apparent diffusion coefficient images (ADC). According to the MRI findings, we reported this tumour as a spinal epidermoid cyst. The pathology result suggested that the lesion was an epidermoid cyst. The second intradural lesion, at the T11 level, showed a hypointense signal on T1 and hyperintense signal on T2 images. However, in contrast to the superior lesion, this lesion was hypointense on DWI and hyperintense on ADC. We evaluated the second lesion as an arachnoid cyst according to the MRI findings.