Computed tomography assessment of maxillary sinus hypoplasia and associated anatomical variations: a systematic review and meta-analysis of global evidence

OBJECTIVE

To summarize the scientific evidence on the prevalence of maxillary sinus hypoplasia (MSH) and associated anatomical variations as assessed by computed tomography scans.

STUDY DESIGN

This PROSPERO-registered systematic review followed the recommendations of the PRISMA guidelines. Search algorithms were constructed for each of the six databases and gray literature. After screening the references (Rayyan®), the extracted data were meta-analyzed according to a random-effects model. The joanna briggs critical appraisal tool assessed the methodological quality of the included studies. The GRADE approach was used to estimate the certainty of the evidence.

RESULTS

From a total of 2781 studies screened, 22 were considered for four meta-analysis. The prevalence of MSH in 7358 patients was 5.65% (CI95% = 4.07-7.47%) with significant heterogeneity between studies (p < 0.001, I2 = 89.30%). MSH was identified in 295 patients, of whom 82.38% (CI95% = 75.82-88.09%) had unilateral hypoplasia and 17.62% (CI95% = 11.91-24.18%) bilateral hypoplasia with moderate heterogeneity between studies (p < 0.0503, I2 = 42.87%). The prevalence of MSH in 9998 maxillary sinuses was 3.77% (95% CI = 2.44-5.38%), with significant heterogeneity between studies (p < 0.001, I2 = 92.84%). Hypoplastic/aplastic uncinate process, concha bullosa and paradoxical concha were the most reported anatomical variations. The studies presented a low-moderate methodological quality. The certainty of the evidence was very low to moderate.

CONCLUSION

The prevalence of maxillary sinus hypoplasia observed was 5.65%, with most cases being unilateral.

Communication between the temporomandibular joint articular space and the extradural space in patients with temporal bone pneumatization: implications for temporomandibular joint surgery

The pneumatization of the articular portion of the temporal bone is an anatomical variant that can modify the barrier between the articular space and the middle cranial fossa. Thus, this study aimed to identify the presence and degree of pneumatization, as well as the existence of pneumatic cell dehiscence towards the extradural or articular space determining whether it could lead to direct communication between the articular and extradural spaces. Hence, One-hundred skull computed tomography images were selected. The presence and extension of pneumatization were classified according to scores 0, 1, 2, and 3. Dehiscence towards extradural and articular spaces was recorded. In total, 200 TMJ from 100 patients were assessed and 40.5% of pneumatization cases were observed. The most prevalent score was 0 (restricted to the mastoid process), while the least prevalent score was 3 (extending beyond the crest of articular eminence). Dehiscence of the pneumatic cells towards the extradural space is more common than towards the articular space. One complete communication between the extradural and articular spaces was observed. Considering the results, it was concluded that to avoid neurological and ontological complications, awareness of the potential anatomical communications between articular and extradural spaces, particularly in patients with extensive pneumatisation, is necessary.

The relation between pericoronary fat thickness and density quantified by coronary computed tomography angiography with coronary artery disease severity

OBJECTIVE

To study the correlation between epicardial fat thickness (EFT), pericoronary fat thickness (PCFT), and pericoronary fat density (PCFD) with the existence and severity of coronary artery disease (CAD).

METHODS

This cross-sectional study included 210 patients referred for multislice CT angiography. Group I normal CTCA, Group II patients had non-obstructive atherosclerosis, and Group III patients had obstructive atherosclerosis. All patients underwent a clinical examination, history taking, and multislice CT angiography.

RESULTS

The mean EFT was significantly greater in group III (10.43 ± 2.31 mm) compared to groups II (6.30 ± 1.61 mm) and I (5.06 ± 1.14 mm). The mean PCFT was significantly greater in group III (17.96 ± 2.89 mm) compared to group II (11.47 ± 2.51 mm) and group I (9.67 ± 1.99 mm). PCFD was significantly higher adjacent to the lesion (-80.47 ± 29.14) compared to the normal segment (-109.03 ± 35.24), higher in the obstructive group (-59.44 ± 20.10) compared to the non-obstructive group (-101.51 ± 20.23), but lower in calcified lesions (-89.58 ± 28.94) compared to non-calcified (-75.01 ± 29.20), and mixed lesions (-74.83 ± 26.90). EFT and PCFT cut-off values for predicting obstructive CAD were 8.3 and 12.4 mm, respectively, with 87.1% and 92.9% sensitivity and 92.9% and 86.4% specificity, respectively.

CONCLUSION

There is a significant association between epicardial fat thickness, pericoronary fat thickness and density with the severity of coronary artery disease.

Quality and safety of coronary computed tomography angiography at academic and non-academic sites: insights from a large European registry (ESCR MR/CT Registry)

OBJECTIVES

To compare the use of coronary computed tomography angiography (CCTA) between academic and non-academic sites across Europe over the last decade.

METHODS

We analyzed a large multicenter registry (ESCR MR/CT Registry) of stable symptomatic patients who received CCTA 01/2010-01/2020 at 47 (22%) academic and 165 (78%) non-academic sites across 19 European countries. We compared image quality, radiation dose, contrast-media-related adverse events, patient characteristics, CCTA findings, and downstream testing between academic and non-academic sites.

RESULTS

Among 64,317 included patients (41% female; 60 ± 13 years), academic sites accounted for most cases in 2010-2014 (52%), while non-academic sites dominated in 2015-2020 (71%). Despite less contemporary technology, non-academic sites maintained low radiation doses (4.76 [2.46-6.85] mSv) with a 30% decline of high-dose scans ( > 7 mSv) over time. Academic and non-academic sites both reported diagnostic image quality in 98% of cases and low rate of scan-related adverse events (0.4%). Academic and non-academic sites examined similar patient populations (41% females both; age: 61 ± 14 vs. 60 ± 12 years; pretest probability for obstructive CAD: low 21% vs. 23%, intermediate 73% vs. 72%, high 6% both, CAD prevalence on CCTA: 40% vs. 41%). Nevertheless, non-academic sites referred more patients to non-invasive ischemia testing (6.5% vs. 4.2%) and invasive coronary angiography/surgery (8.5% vs. 5.6%).

CONCLUSIONS

Non-academic and academic sites provide safe, high-quality CCTA across Europe, essential to successfully implement the recently updated guidelines for the diagnosis and management of chronic coronary syndromes. However, despite examining similar populations with comparable CAD prevalence, non-academic sites tend to refer more patients to downstream testing.

KEY POINTS

• Smaller non-academic providers increasingly use CCTA to rule out obstructive coronary artery disease. • Non-academic and academic sites provide comparably safe, high-quality CCTA across Europe. • Compared to academic sites, non-academic sites tend to refer more patients to downstream testing.

Cardiac Decompression by Pericardiectomy for Constrictive Pericarditis: Multimodality Imaging to Identify Patients at Risk for Prolonged Inotropic Support

BACKGROUND

Post-pericardiectomy right ventricular (RV) failure has been reported but it remains not well-studied. To investigate imaging parameters that could predict RV function and the outcome of patients post-pericardiectomy.

METHODS

We analysed data from a total of 53 CP patients undergoing pericardiectomy. Preoperative, early and at 6 months postoperative echocardiographic (echo) imaging datasets were analysed and correlated with preoperative cardiac magnetic resonance (CMR), cardiac computed tomography scans and histology. The primary endpoint of the study was RV functional status early postoperatively and at 6 months. Secondary endpoint was the need for prolonged inotropic support.

RESULTS

A cause of CP was identified in 26 patients (49%). Inotropic support ≥ 48 hours was required in n = 28 (53%) of patients and was correlated with lower preoperative RV areas by echo or RV volumes by CMR (p < 0.05 for all). A pericardial score based on pericardial thickness/calcification and epicardial fat thickness had good diagnostic accuracy to identify patients requiring prolonged use of inotropes (area under the curve, 0.825; 95% confidence interval, 0.674–0.976). Pericardiectomy resulted in RV decompression and impaired RV function early postoperatively (fractional area change: 40.5% ± 8.8% preoperatively vs. 31.4% ± 10.4% early postoperatively vs. 42.5% ± 10.2% at 6 months, p < 0.001).

CONCLUSIONS

We show that a smaller RV cavity size and a pericardial scoring system are associated with prolonged inotropic support in CP patients undergoing pericardiectomy. RV systolic impairment post decompression is present in most patients, but it is only transient.

Stapes visualization by ultra-high resolution CT in cadaveric heads: A preliminary study

PURPOSE

This study aimed to assess stapes visualization using an ultra-high resolution computed tomography (U-HRCT).

METHOD

Sixty ears from 30 cadaveric human heads were scanned by both U-HRCT and 128-section multislice CT (MSCT) with clinical parameters. Image quality of the stapes head, anterior and posterior crura, footplate, incudostapedial joint and stapedial muscle within the pyramidal eminence was scored using a 3-point Likert scale. Linear measurements of the stapes configuration were performed on U-HRCT.

RESULTS

The interobserver agreement for image qualitative score on U-HRCT was good to excellent (interobserver agreement coefficients 0.65-0.86). With the exception of the stapes head, U-HRCT achieved significantly higher qualitative scores than MSCT across all anatomical structures (Ps < 0.05). The total height of the stapes was measured to be 3.48 ± 0.33 mm. The height and width of the obturator foramen were 1.77 ± 0.28 mm and 2.19 ± 0.33 mm, respectively. The widths of the anterior and posterior crura were 0.20 ± 0.06 mm and 0.22 ± 0.06 mm, respectively. The thickness of the footplate was 0.22 ± 0.06 mm, and the angle of the incudostapedial joint was 95.91 ± 10.69°.

CONCLUSIONS

U-HRCT is capable of delineating fine structures of the stapes and provides linear data on dimensions of the stapes, which could be helpful for detecting stapes disease and making individualized surgical plans in the clinical setting.

The role of computed tomography coronary angiography in multi-vessel coronary vasospasm: a case report

Background

Coronary vasospasm can present like an acute coronary syndrome (ACS) with an intense vasoconstriction resulting in total or near-total occlusion of one or more of the coronary vessels. Definitive diagnosis can be made by intracoronary provocation testing.

Case summary

A 37-year-old Caucasian male and smoker was admitted with chest pain. Highly sensitive troponin-I was positive at 63 ng/L (99th percentile upper reference limit, <15 ng/L) with a repeat value of 45 ng/L three and a half hours later which was of clinical significance. Serial electrocardiography (ECG) showed no ischaemic changes. Coronary angiography revealed several distal and side branch stenoses; however, angiographic appearances were atypical of coronary plaque. A differential diagnosis of spontaneous coronary artery dissection was suspected although the patient was pain free during the procedure. Computed tomography coronary angiography (CTCA) demonstrated normal coronary arteries, confirmed on repeat invasive coronary angiography. Cold pressor testing was unsuccessful in reproducing vasospasm. Acute coronary syndrome treatment was discontinued, he received smoking cessation advice and Amlodipine 5 mg daily was started. He has experienced no further episodes of cardiac chest pain on follow-up consultation 7 months later.

Discussion

This is an unusual case of persistent, extensive coronary vasospasm in a patient without ongoing chest pain or ischaemic ECG changes. Intracoronary nitrates are usually effective at relieving coronary spasm. Cold pressor testing has poor sensitivity for diagnosing vasospasm when compared to intracoronary provocation testing using either acetylcholine or ergonovine. Multi-slice CTCA may help to discriminate coronary plaque from coronary vasospasm when there is diagnostic uncertainty.

Practicability and Diagnostic Yield of One-Stop Stroke CT with Delayed-Phase Cardiac CT in Detecting Major Cardioembolic Sources of Acute Ischemic Stroke : A Proof of Concept Study

Purpose

Recurrent stroke is considered to increase the incidence of severe disability and death. For correct risk assessment and patient management it is essential to identify the origin of stroke at an early stage. Transthoracic echocardiography (TTE) is the initial standard of care for evaluating patients in whom a cardioembolic source of stroke (CES) is suspected but its diagnostic capability is limited. Transesophageal echocardiography (TEE) is considered as gold standard; however, this approach is time consuming, semi-invasive and not always feasible. We hypothesized that adding a delayed-phase cardiac computed tomography (cCT) to initial multimodal CT might represent a valid alternative to routine clinical echocardiographic work-up.

Material and Methods

Patients with suspected acute cardioembolic stroke verified by initial multimodal CT and subsequently examined with cCT were included. The cCT was evaluated for presence of major CES and compared to routine clinical echocardiographic work-up.

Results

In all, 102 patients with suspected acute CES underwent cCT. Among them 60 patients underwent routine work-up with echocardiography (50 TTE and only 10 TEE). By cCT 10/60 (16.7%) major CES were detected but only 4 (6.7%) were identified by echocardiography. All CES observed by echocardiography were also detected by cCT. In 8 of 36 patients in whom echocardiography was not performed cCT also revealed a major CES.

Conclusion

These preliminary results show the potential diagnostic yield of delayed-phase cCT to detect major CES and therefore could accelerate decision-making to prevent recurrence stroke. To confirm these results larger studies with TEE as the reference standard and also compared to TTE would be necessary.

Anatomical variations and congenital anomalies of the ribs revisited by multidetector computed tomography

As they are asymptomatic or have a nonspecific, anatomical variations of the ribs are usually detected as incidental findings on imaging studies. They may be isolated changes or can be related to anomalies or clinical syndromes. Such variations are easily overlooked on conventional radiography and computed tomography if they are not actively investigated, mainly because most indications for a chest X-ray studies aim to evaluate the lung parenchyma and mediastinal structures. The objective of this pictorial essay was to use multislice computed tomography images to illustrate the imaging aspects of the main anatomical variations and congenital anomalies of the ribs.

Hepatocellular carcinoma in an adult with Alagille syndrome: case report and literature review

Alagille syndrome (AS) is an autosomal dominant multisystem disorder which can lead to hepatopathy and the development of focal hepatic lesions. The majority of the hepatic lesions are benign, including regenerative nodules, focal hyperplasia, and adenoma. Hepatocellular carcinoma (HCC) is extremely rare in AS, with very few cases reported in the literature. A 38-year-old man complaining of acute right upper quadrant pain with long-standing diagnosis of Alagille syndrome. On imaging, the patient had a large hepatic mass in the right lobe, with arterial hyperenhancement, washout appearance, and areas of internal hemorrhage. The patient underwent a right hepatectomy and histopathology demonstrated HCC. The patient passed away 3 months after the surgery due to infectious complications. HCC is a rare complication of AS, although rare, it should be considered. This case also emphasizes the need of HCC screening in patients with AS in order to allow an early diagnosis and treatment, which can improve patients' outcome.

Is fasting still necessary prior to contrast-enhanced computed tomography? A randomized clinical study

OBJECTIVES

There is very limited evidence to support the common practice of preparative fasting prior to contrast-enhanced computerized tomography (CT). This study examined the effect of withholding fasting orders, prior to contrast-enhanced CT, on the incidence of aspiration pneumonitis and adverse gastrointestinal symptoms.

METHODS

This randomized controlled trial enrolled hospitalized patients referred for non-emergency, contrast-enhanced CT scan to either at least 4 h of fasting or to an unrestricted consumption of liquids and solids up to the time of CT. The primary outcome was incidence of aspiration pneumonitis and the secondary outcomes were rates of adverse gastrointestinal symptoms (nausea and/or vomiting).

RESULTS

After excluding participants with incomplete follow-up, a total of 1080 participants were assigned to the fasting group and 1011 were assigned to the non-fasting group. Aspiration pneumonitis was not identified in either group. The mean time of fasting in the fasting group was 8.4 ± 1.6 h. Rates of nausea and vomiting were not statistically different between the fasting group compared with the non-fasting group, 6.6% vs. 7.6% (p = 0.37) and 2.6% vs. 3.0% (p = 0.58), respectively. A subgroup analysis of patients who were required to drink oral contrast agent (n = 1257) showed that rates of nausea and vomiting were not statistically different between the fasting and non-fasting groups, 6.8% vs. 8.0% (p = 0.42) and 2.6% vs. 3.6% (p = 0.3), respectively.

CONCLUSIONS

Withholding fasting orders prior to contrast-enhanced CT was not associated with a greater risk of aspiration pneumonitis or a significant increase in rates of adverse gastrointestinal symptoms.

TRIAL REGISTRATION

ClinicalTrials.gov : NCT03533348 KEY POINTS: • Is fasting necessary prior to contrast-enhanced computed tomography (CT)? • In this randomized clinical study including 2091 participants referred to non-emergency contrast-enhanced CT scan, withholding preparative fasting was not associated with a greater risk of aspiration pneumonitis or clinically significant increase in rates of adverse gastrointestinal symptoms. • Eating and drinking prior to contrast-enhanced CT can be allowed and are not associated with an increased risk of aspiration pneumonitis.

Thoracic tomographic manifestations in symptomatic respiratory patients with COVID-19

China was the epicenter for the novel coronavirus disease (COVID-19), which quickly spread to other Asian countries and later to Western countries; subsequently, COVID-19 was categorized as a pandemic by the World Health Organization. Diagnosis primarily depends on viral detection in respiratory samples; however, available kits are limited, lack high sensitivity, and have a long turnaround time for providing results. In this scenario, computed tomography has emerged as an efficient and available high-sensitivity method, allowing radiologists to readily recognize findings related to COVID-19. The objective of this article is to demonstrate the main tomographic findings in symptomatic respiratory patients with COVID-19 to assist medical professionals during this critical moment.

Frequency of de novo atrial fibrillation in patients presenting with acute ischemic cerebrovascular stroke

BACKGROUND

Atrial fibrillation (AF) affects millions of people worldwide and can remain undiagnosed for years. It is a major cause of cerebrovascular stroke (CVS); hence, early detection is extremely important in order to decrease the risk of CVS. We conducted a retrospective observational study looking into the prevalence of silent AF in 3299 patients admitted from January 2014 to December 2017 in a tertiary care stroke specialized center. Ischemic CVS was confirmed either by using multislice computed tomography (MSCT) or magnetic resonance imaging (MRI) of the brain. AF was diagnosed by electrocardiography (ECG) at the time of admission or during the hospital stay. Patients with a history of AF were excluded from the study.

RESULTS

Of the 3299 patients admitted by acute ischemic CVS, 707 (21.43%) had a history of AF and thus were excluded from the study. Of the remaining 2592 patients eligible for the study, 1666 (64.27%) were males with a mean age of 56.06 years (± 16.01). A total of 2313 (89.24%) patients remained in sinus rhythm throughout the hospital stay, 211 (8.14%) patients were in AF on admission, and 68 (2.62 %) patients developed AF during their hospital stay. The total number of newly diagnosed patients with AF was 279 (10.76%).

CONCLUSION

The prevalence of de novo atrial fibrillation in patients presented with acute cerebrovascular stroke is high. The implementation of good screening programs can significantly reduce the risk of disabilities and morbidities.

Comparison of diagnostic performance between CT and MRI for detection of cartilage invasion for primary tumor staging in patients with laryngo-hypopharyngeal cancer: a systematic review and meta-analysis

OBJECTIVE

To compare the diagnostic performance of contrast-enhanced CT with that of MRI in the detection of cartilage invasion in patients with laryngo-hypopharyngeal cancer.

METHODS

A systematic literature search in the Ovid-MEDLINE and EMBASE databases was performed for studies reporting diagnostic accuracy of CT and/or MRI in detecting cartilage invasion from laryngo-hypopharyngeal cancer between 2000 and 2018. The pooled sensitivity and specificity, and their 95% confidence intervals were calculated for CT and MRI using bivariate random effects modeling. Subgroup and meta-regression analyses were performed. Indirect comparison was also performed by univariable meta-regression.

RESULT

Fourteen articles including 776 patients were included in the systematic review and meta-analysis: eight for CT, and six for MRI. CT and MRI showed pooled sensitivities of 66% (95% CI, 49-80%) and 88% (95% CI, 79-93%), and pooled specificities of 90% (95% CI, 82-94%) and 81% (95% CI, 76-84%), respectively. MRI showed significantly higher sensitivity than CT (p = 0.02). The specificities showed no statistically significant difference between CT and MRI (p = 0.39). The CT studies showed heterogeneity and a threshold effect, while MRI showed neither heterogeneity nor threshold effect. In the meta-regression analysis for CT, the type of cartilage analyzed (thyroid only vs. thyroid/cricoid/arytenoid, p < 0.001) was a significant factor influencing the heterogeneity in the diagnostic performance of the CT studies.

CONCLUSIONS

In conclusion, MRI has significantly higher sensitivity than CT for detecting cartilage invasion in patients with laryngo-hypopharyngeal cancer, without a significant difference in the specificity.

KEY POINTS

• MRI has significantly higher sensitivity than CT for detecting cartilage invasion in patients with laryngo-hypopharyngeal cancer.

The role of radiological and hybrid imaging for muscle metastases: a systematic review

AIM OF THE STUDY

Skeletal muscle metastases (SMM) are a rare entity, mainly detected at autopsy. Nevertheless, radiological and nuclear medicine imaging can contribute to the diagnosis with a significant impact on the treatment and prognosis of neoplastic patients. This study aimed to systematically review the features of SMM at imaging considering the primary tumors and the sites of occurrence.

MATERIALS AND METHODS

We conducted a systematic search of three electronic database (i.e., PubMed, Science Direct, and Web of Science) up to May 2019, without any language or time interval restriction. Two reviewers performed the search and selection process, data extraction, and synthesis. We resolved disagreements by consensus and/or involving a third reviewer. The included studies have been classified according to the Oxford Centre for Evidence Based Medicine (CEBM) grading system.

RESULTS

Out of 8598 and 1077 articles respectively for radiological and hybrid imaging, 29 papers were included. According to CEBM, twelve were level 4. Computed tomography (CT) is mainly applied and, despite the existence of CT and magnetic resonance-based classifications, these are rarely used. Positron emission tomography/CT allowed the detection of small and subtle lesion also in the extremities. Muscles of the trunk were mostly affected and mainly respiratory tumors are associated with this type of metastatic spread.

CONCLUSION

Radiological and hybrid imaging allow a precise characterization of SMM. However, a more systematic approach, including also the application of available classification systems, may increase the diagnostic accuracy for this rare type of metastases.

KEY POINTS

• Skeletal muscle metastases have heterogeneous characteristics at imaging but mostly abscess-like features and high metabolic activity are described. • Skeletal muscle metastases mainly affect the muscles of the trunk. • Pulmonary, urological, and gastrointestinal cancers are the most frequent cause of skeletal muscle metastases.

Analysis of CT characteristics in the diagnosis of Schistosoma japonicum associated appendicitis with clinical and pathological correlation: a diagnostic accuracy study

PURPOSE

To clarify unique non-contrast CT (NCCT) characteristics for early recognition of Schistosomal associated appendicitis (SAA) differentiating from Non-schistosomal associated appendicitis (NSA).

MATERIAL AND METHODS

Clinical and pathological data of 50 cases with SAA and 60 cases with NSA who underwent emergency appendectomy were retrospectively compared to pre-surgical NCCT features such as direct and indirect signs of acute appendicitis as well as appendicoliths, colon calcifications as diagnostic criteria. Statistical methods such as Chi-square (χ²), t-tests, Principal component analysis (PCA), Binary Logistic regression (LR) and Factor Analysis (FA) were utilized to observe differences and isolate recognizable CT features of SAA. Pre and post hoc diagnostic performance of all criteria was calculated as sensitivity, specificity, and the Odds Ratio (OR).

RESULTS

Age > 50 years, diameter > 13 mm, pneumatosis, peri appendiceal abscess, focal wall defect, perforation; Orbital, linear and point types of appendicular wall calcifications; sigmoid colon and cecal curvilinear calcifications were observed as unique characteristics with a sensitivity of 84-95% and specificity of 91-98% in predicting SAA by OR of 6.2 times. Pre and post hoc hypothetical analysis did not show any significance for all other factors.

CONCLUSION

Factors such as elderly age, CT features such as larger appendicular diameter, appendicular wall calcifications along with sigmoid colon, and cecal calcifications, signs of perforation or abscess are characteristic for early recognition of SAA.

Comparison of the geometry of the left ventricle outflow tract, the aortic root and the ascending aorta in patients with severe tricuspid aortic stenosis versus healthy controls

The purpose of this study was to assess by multislice computed tomography (MSCT) imaging geometry of the ascending aorta, the aortic root, the aortic annulus and the left ventricle outflow tract (LVOT) in aortic stenosis (AS) patients, to compare aortic root morphology in patients with AS with healthy controls and to evaluate sex differences. Fifty patients with severe AS and 50 age- and gender-matched controls who underwent MSCT were included in the study. The dimensions of the LVOT, the aortic annulus, the aortic root, the ascending aorta, and the volume of the aortic root were retrospectively assessed and a comparison was made between patients with severe tricuspid AS and controls. Patients with tricuspid AS in comparison with controls had smaller dimensions of the sinus of Valsalva resulting in reduction of the aortic root volume, whereas the dimensions of the other structures were comparable. MSCT revealed larger annular, LVOT and the sinus of Valsalva dimensions and the aortic root volume in men than women. Men with AS differed from healthy men only in regard to the dimensions of the sinus of Valsalva, while women showed significant differences also in the LVOT, and the aortic annulus. MSCT showed accurately aortic root remodeling in tricuspid AS patients and indentified sex-dependent differences. Women with tricuspid AS differ from healthy women more than men did. A high degree of the variability in the aortic root dimensions requires further careful research.

Precise diagnosis of intracranial hemorrhage and subtypes using a three-dimensional joint convolutional and recurrent neural network

OBJECTIVES

To evaluate the performance of a novel three-dimensional (3D) joint convolutional and recurrent neural network (CNN-RNN) for the detection of intracranial hemorrhage (ICH) and its five subtypes (cerebral parenchymal, intraventricular, subdural, epidural, and subarachnoid) in non-contrast head CT.

METHODS

A total of 2836 subjects (ICH/normal, 1836/1000) from three institutions were included in this ethically approved retrospective study, with a total of 76,621 slices from non-contrast head CT scans. ICH and its five subtypes were annotated by three independent experienced radiologists, with majority voting as reference standard for both the subject level and the slice level. Ninety percent of data was used for training and validation, and the rest 10% for final evaluation. A joint CNN-RNN classification framework was proposed, with the flexibility to train when subject-level or slice-level labels are available. The predictions were compared with the interpretations from three junior radiology trainees and an additional senior radiologist.

RESULTS

It took our algorithm less than 30 s on average to process a 3D CT scan. For the two-type classification task (predicting bleeding or not), our algorithm achieved excellent values (≥ 0.98) across all reporting metrics on the subject level. For the five-type classification task (predicting five subtypes), our algorithm achieved > 0.8 AUC across all subtypes. The performance of our algorithm was generally superior to the average performance of the junior radiology trainees for both two-type and five-type classification tasks.

CONCLUSIONS

The proposed method was able to accurately detect ICH and its subtypes with fast speed, suggesting its potential for assisting radiologists and physicians in their clinical diagnosis workflow.

KEY POINTS

• A 3D joint CNN-RNN deep learning framework was developed for ICH detection and subtype classification, which has the flexibility to train with either subject-level labels or slice-level labels. • This deep learning framework is fast and accurate at detecting ICH and its subtypes. • The performance of the automated algorithm was superior to the average performance of three junior radiology trainees in this work, suggesting its potential to reduce initial misinterpretations.

Assessment of a Radiomic Signature Developed in a General NSCLC Cohort for Predicting Overall Survival of ALK-Positive Patients With Different Treatment Types

BACKGROUND

The purpose of the study was to investigate the potential of a radiomic signature developed in a general non-small-cell lung cancer (NSCLC) cohort for predicting the overall survival of anaplastic lymphoma kinase (ALK)-positive (ALK⁺) patients with different treatment types.

MATERIALS AND METHODS

After test-retest in the Reference Image Database to Evaluate Therapy Response data set, 132 features (intraclass correlation coefficient > 0.9) were selected in the least absolute shrinkage and selection operator Cox regression model with a leave-one-out cross-validation. The NSCLC radiomics collection from The Cancer Imaging Archive was randomly divided into a training set (n = 254) and a validation set (n = 63) to develop a general radiomic signature for NSCLC. In our ALK⁺ set, 35 patients received targeted therapy and 19 patients received nontargeted therapy. The developed signature was tested later in this ALK⁺ set. Performance of the signature was evaluated with the concordance index (C-index) and stratification analysis.

RESULTS

The general signature had good performance (C-index > 0.6; log rank P < .05) in the NSCLC radiomics collection. It includes 5 features: Geom_va_ratio, W_GLCM_Std, W_GLCM_DV, W_GLCM_IM2, and W_his_mean. Its accuracy of predicting overall survival in the ALK⁺ set achieved 0.649 (95% confidence interval [CI], 0.640-0.658). Nonetheless, impaired performance was observed in the targeted therapy group (C-index = 0.573; 95% CI, 0.556-0.589) whereas significantly improved performance was observed in the nontargeted therapy group (C-index = 0.832; 95% CI, 0.832-0.852). Stratification analysis also showed that the general signature could only identify high- and low-risk patients in the nontargeted therapy group (log rank P = .00028).

CONCLUSION

This preliminary study suggests that the applicability of a general signature to ALK⁺ patients is limited. The general radiomic signature seems to be only applicable to ALK⁺ patients who had received nontargeted therapy, which indicates that developing special radiomics signatures for patients treated with tyrosine kinase inhibitors might be necessary.

A rare case of idiopathic congenital megaduodenum in adult misinterpreted during childhood: case report and literature review

Intestinal malformations are common disorders in newborn and favorable outcomes have been reported for such conditions. Although, if the patient is treated in a not experienced center, misinterpretation of the clinical and radiological findings may lead to errors in treatment and possible complications in adulthood. We report a case of a congenital megaduodenum which was misinterpreted as an intestinal malrotation resulting in late complications. The patient underwent a successful surgical resection of the duodenum with improvement of his clinical symptoms and nutritional status.

This case report emphasizes the importance of considering megaduodenum in the differential diagnosis of patients with feeding impairment, even during adulthood. Early diagnosis and treatment may improve patients’ outcome and reduce morbidity.

Effect of image reconstruction algorithms on volumetric and radiomic parameters of coronary plaques

BACKGROUND

Volumetric and radiomic analysis of atherosclerotic plaques on coronary CT angiography have been shown to predict high-risk plaque morphology and to predict patient outcomes. However, there is limited information whether image reconstruction algorithms and preprocessing steps (type of binning, number of bins used for discretization) may influence parameter values.

METHODS

We retrospectively identified 60 coronary lesions on coronary CT angiography (CTA). All images were reconstructed using filtered back projection (FBP), hybrid (HIR) and model-based (MIR) iterative reconstruction. Plaques were segmented manually on HIR images and copied to FBP and MIR images to ensure identical voxels were analyzed. Overall, 4 volumetric and 169 radiomic parameters were calculated. Intra-class correlation coefficient (ICC) was used to assess reproducibility between image reconstructions, while linear regression analysis was used to assess the effect of preprocessing steps done before calculating radiomic metrics.

RESULTS

All volumetric and radiomic metrics had ICC>0.90 except for first-order statistics: mode, harmonic mean, minimum (0.45, 0.76, 0.84; respectively) and gray level co-occurrence (GLCM) parameters: inverse difference sum and sum variance (0.01, 0.04; respectively). Among GLCM parameters 90% were significantly affected by the type of binning and 100% by the number of bins. In case of gray level run length matrix parameters 100% of metrics were affected by both preprocessing steps.

CONCLUSIONS

Volumetric and radiomic statistics are robust to image reconstruction algorithms. However, all radiomic variables were affected by preprocessing steps therefore, showing the need for standardization before being implemented into everyday clinical practice.

Two rare cases of congenital aortic stenosis showing a discrepancy between preoperative imaging diagnosis, intraoperative findings, and histopathological diagnosis

Unicuspid aortic valve (UAV) is an extremely rare congenital heart valve abnormality while bicuspid valve (BAV) has been reported as one of the most common cardiac anomalies. With a UAV usually showing similar presentations to a BAV, such as aortic regurgitation or aortic stenosis (AS), it is challenging to differentiate them from each other in clinical settings. Despite some features shared between both valve disorders, there can be a clinical significance in distinguishing UAV from BAV for the management of patients with these heart anomalies. Herein, we describe two cases where patients with hemodynamically severe AS were diagnosed with BAV and UAV, respectively based on preoperative examinations and intraoperative findings, but subsequent pathological examinations confirmed the opposite diagnosis in both cases. <Learning objective: Preoperative diagnosis of congenital aortic valve diseases can often be challenging. There remains a remarkable number of misleading cases. Thus, it is strongly recommended that an accurate diagnosis should be attempted at the earliest stages of congenital aortic valve disease. Additionally, both careful follow-ups using multiple imaging modalities and confirmations via pathological diagnosis for patients undergoing surgery, if they are first found to be at an advanced stage or remain undiagnosed preoperatively are important.>.

Incidental findings in multislice computed tomography prior to transcatheter aortic valve implantation: frequency, clinical relevance and outcome

Multislice computed tomography (MSCT) has emerged as the mainstay in patients planned for transcatheter aortic valve implantation (TAVI). Incidental findings (IF) in MSCT are common. However, the exact incidence, clinical relevance and further consequences of IF are unclear and it is controversial whether IF adversely affect patients' outcome. We analyzed MSCT data of 1050 patients screened for TAVI between January 2011 and December 2014. Median follow-up of patients was 20 months. In total, 3194 IF were identified, which were classified into clinically non-relevant IF (2872, 90%) and clinically relevant IF (322, 10%). In 25% of patients (258/1050) at least one clinically relevant IF was present. Age (80 ± 7 vs. 80 ± 7 years; p = 0.198) and EuroSCORE II (3.6% [2.1-5.7] vs. 3.6% [2.1-5.9]; p = 0.874) was similar between patients with and without a clinically relevant IF. TAVI was performed less frequently in patients with a clinically relevant IF (76% vs. 85%; p < 0.001), with more patients receiving surgical aortic valve replacement in that group (14% vs. 11%; p = 0.042), possibly due to the high rate of incidental aneurysms of the ascending aorta (n = 48). If TAVI was performed mortality did not differ (30-days: 4% vs. 3%; p = 0.339, 1-year: 11% vs. 14%; p = 0.226) between patients with and without a clinically relevant IF. Our study is the largest study to analyze prevalence, clinical relevance and therapeutic consequences of IF during screening for TAVI. IF in pre-procedural MSCT are common and clinically relevant in one-quarter of patients. However, these findings had no impact on overall mortality.

Ultralow Dose MSCT Imaging in Dental Implantology

INTRODUCTION

The Council Directive 2013/59 Euratom has a clear commitment for keeping medical radiation exposure as low as reasonably achievable and demands a regular review and use of diagnostic reference levels.

METHODS

In dental implantology, the range of effective doses for cone beam computed tomography (CBCT) shows a broad overlap with multislice computed tomography (MSCT). More recently, ultralow dose imaging with new generations of MSCT scanners may impart radiation doses equal to or lower than CBCT. Dose reductions in MSCT have been further facilitated by the introduction of iterative image reconstruction technology (IRT), which provides substantial noise reduction over the current standard of filtered backward projection (FBP).

AIM

The aim of this article is to review the available literature on ultralow dose CT imaging and IRTs in dental implantology imaging and to summarize their influence on spatial and contrast resolution, image noise, tissue density measurements, and validity of linear measurements of the jaws.

CONCLUSION

Application of ultralow dose MSCT with IRT technology in dental implantology offers the potential for very large dose reductions compared with standard dose imaging. Yet, evaluation of various diagnostic tasks related to dental implantology is still needed to confirm the results obtained with various IRTs and ultra-low doses so far.

Advances in the Study of the Middle Cranial Fossa through Cutting Edge Neuroimaging Techniques

The objective of this paper is to present a morphometric study of the middle cranial fossa from the study of 87 patients using cutting edge multislice computed tomography scans (32 detectors) and Magnetic Resonance Imaging. The study presents a detailed anatomical-radiological and morphometric analysis of the middle cranial fossa as well as its neurovascular elements in normal conditions. The implications of this investigation in training and clinical contexts are discussed.

Evaluation of the multi-slice computed tomography outcomes in diaphragmatic injuries related to penetrating and blunt trauma

PURPOSE

Traumatic diaphragmatic rupture is a diagnostic challenge for both surgeons and radiologists and generally occurs secondary to blunt and penetrating trauma of thoracoabdominal region.

MATERIAL AND METHODS

56 patients who underwent surgical procedure due to blunt or penetrating trauma were included to the study.

RESULTS

There were 37 diaphragmatic ruptures in the left side and 19 patients in the right side. The most common radiological finding was "the direct monitoring of defect" (54,3%).

CONCLUSION

Findings suggestive of diaphragmatic rupture must be carefully evaluated in patients with blunt or penetrating thoracoabdominal trauma.

Short-term evaluation of tegumentary changes of the nose in oral breathers undergoing rapid maxillary expansion

Introduction

Rapid maxillary expansion is an orthodontic and orthopedic procedure that can change the form and function of the nose. The soft tissue of the nose and its changes can influence the esthetics and the stability of the results obtained by this procedure.

Objective

The objective of this study was to assess the changes in nose dimensions after rapid maxillary expansion in oral breathers with maxillary atresia, using a reliable and reproducible methodology through computed tomography.

Methods

A total of 30 mouth-breathing patients with maxillary atresia were analyzed and divided into a treatment group who underwent rapid maxillary expansion (20 patients, 10 of which were male and 10 female, with a MA of 8.9 years and a SD of 2.16, ranging from 6.5 to 12.5 years) and a Control Group (10 patients, 5 of which were male and 5 female, with a MA of 9.2 years, SD of 2.17, ranging from 6.11 to 13.7 years). In the treatment group, multislice computed tomography scans were obtained at the start of the treatment (T1) and 3 months after expansion (T2). The patients of the control group were submitted to the same exams at the same intervals of time. Four variables related to soft tissue structures of the nose were analyzed (alar base width, alar width, height of soft tissue of the nose and length of soft tissue of the nose), and the outcomes between T1 and T2 were compared using Osirix MD software.

Results

In the TG, the soft tissues of the nose exhibited significant increases in all variables studied (p < 0.05), whereas, changes did not occur in the control group (p > 0.05). In the treatment group, mean alar base width increased by 4.87% (p = 0.004), mean alar width increased by 4.04% (p = 0.004), mean height of the soft tissues of the nose increased by 4.84% (p = 0.003) and mean length of the soft tissues of the nose increased by 4.29% (p = 0.012).

Conclusion

In short-term, rapid maxillary expansion provided a statistically significant increase in the dimensions of the soft tissues of the nose.

Imaging for planning of transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) has proven to be the standard of care for patients with prohibitive and high operative risk; today, it is considered a reasonable alternative to surgical aortic valve replacement in intermediate-risk patients. As indications for TAVI move toward patients at lower risk, safety aspects are becoming even more important. Furthermore, adequate patient selection is key for predictable procedural success with minimal complications, translating into an optimal clinical outcome. Decisions on valve type and size as well as on the access route are based on multimodality imaging including echocardiography, multislice computed tomography, and cardiac catheterization with peripheral angiography. This combination of multiple imaging modalities provides the best picture of a patient's anatomical and physiological suitability for the TAVI procedure. Yet, the reliability of preprocedural imaging is influenced by the quality of the images, which should be as high as possible, and both image acquisition and interpretation should be performed in a standardized manner. This article provides a concise overview of standardized multimodality imaging for the preprocedural planning and assessment of patients undergoing TAVI.

Single coronary artery presenting as acute myocardial infarction

A single coronary artery is one of the most rarely seen coronary artery anomalies. In addition, the specific subtype (Lipton RII-A) that our patient presented is one of the least common, and its clinical presentation as myocardial infarction and cardiac arrest has not been described in the literature. The case shows that although it is essential to exclude a malignant interarterial course of the vessel, cardiac arrest is a possible clinical presentation produced by myocardial ischemia in the context of acute myocardial infarction and should be managed according to clinical practice guidelines.

Bone age estimation based on multislice computed tomography study of the scapula

Progress in medical imaging has opened new areas of research in forensic anthropology, especially in the context of the study of bone age assessment. The study of bone age has become a useful tool for age estimation at death or age of young adult migrants in an anthropological context. We retrospectively evaluated multislice computed tomography (MSCT) explorations focused on scapulae of 232 individuals (123 males; 109 females) aged between 8 and 30 years old. Computed tomography (CT) scans were viewed in axial and multiplanar reconstructed images using OsiriX 5.9 (64 bit)®. The ossification centers of the scapula studied were as follows: acromial, sub-coracoid, glenoid, coracoid, coracoid apex, and inferior angle epiphyses. Fusion status was scored based on a five-stage system (stage 1: no ossification, stage 2: visualization of an ossification center, stage 3: partial ossification, stage 4: full ossification associated to an epiphyseal scar, and stage 5: full ossification without epiphyseal scar). Intra-observer variability was excellent, and inter-observer variability was good, demonstrating the reliability of this MSCT staging system. The fusion of scapular ossification centers was statistically associated with age (p < 0.001) but not with sex (p > 0.05). In conclusion, MSCT of the scapula is an efficient method for age assessment, which is complementary to preexisting methods particularly for specifying the 18-year threshold. Further studies with larger groups are needed to support our results.

In Vitro Comparison of Second- and Third-generation Dual-source CT for Coronary Stent Visualization at Different Tube Potentials

RATIONALE AND OBJECTIVES

The study aimed to evaluate in vitro stent lumen visibility of coronary stents in a second- and third-generation dual-source computed tomography (CT) system at 100 and 120 kVp tube potential.

MATERIALS AND METHODS

Twenty-six coronary stents ranging from 2.25 to 4.0 mm in diameter were implanted in a coronary vessel phantom. Scans were performed at 100 and 120 kVp tube potential. Evaluation was performed using a medium-sharp kernel in both systems (B46f in the second-generation and Bv49 in the third-generation model) and a sharp (Bv59) convolution kernel optimized for vascular imaging in the third-generation CT.

RESULTS

The median visible stent lumen diameter in the second-generation system was higher at 120 kVp with a median of 62.0% compared to 56.3% at 100 kVp (P < 0.001). The median visible diameter in the third-generation system was significantly higher applying the Bv49 kernel with 66.7% at 120 kVp and 61.1% at 100 kVp (both P < 0.001). When applying the Bv59 kernel, visible stent lumen further increased to 69.3% at 120 kVp and 66.7% at 100 kVp. Additionally, stent lumen was assessed using full width at half maximum, resulting in a comparable increase in luminal diameter at corresponding tube potential.

CONCLUSIONS

Third-generation dual-source CT provides superior stent lumen visibility at equivalent tube potential and at reduced tube potential of 100 kVp when compared to 120 kVp in a second-generation system, at least when manually assessed.

The added value of 68Ga-DOTA-TATE-PET to contrast-enhanced CT for primary site detection in CUP of neuroendocrine origin

OBJECTIVES

To quantify the additional value of ⁶⁸Ga-DOTA-TATE PET/CT in comparison with contrast-enhanced CT alone for primary tumour detection in neuroendocrine cancer of unknown primary (CUP-NET).

METHODS

In total, 38 consecutive patients (27 men, 11 women; mean age 62 years) with histologically proven CUP-NET who underwent a contrast-enhanced ⁶⁸Ga-DOTA-TATE PET/CT scan for primary tumour detection and staging between 2010 and 2014 were included in this IRB-approved retrospective study. Two blinded readers independently analysed the contrast-enhanced CT and ⁶⁸Ga-DOTA-TATE PET datasets separately and noted from which modality they suspected a primary tumour. Consensus was reached if the results were divergent. Postoperative histopathology (24 patients) and follow-up ⁶⁸Ga-DOTA-TATE PET/CT imaging (14 patients) served as the reference standards and statistical measures of diagnostic accuracy were calculated accordingly.

RESULTS

The majority of confirmed primary tumours were located in the abdomen (ileum in 19 patients, pancreas in 12, lung in 2, small pelvis in 1). High interobserver agreement was noted regarding the suspected primary tumour site (Cohen's k 0.90, p < 0.001). ⁶⁸Ga-DOTA-TATE PET demonstrated a significantly higher sensitivity (94 % vs. 63 %, p = 0.005) and a significantly higher accuracy (87 % vs. 68 %, p = 0.003) than contrast-enhanced CT.

CONCLUSIONS

Ga-DOTA-TATE PET/CT compared with contrast-enhanced CT alone provides an improvement in sensitivity of 50 % and an improvement in accuracy of 30 % in primary tumour detection in CUP-NET.

KEY POINTS

• ⁶⁸Ga-DOTA-TATE PET augments the sensitivity of contrast-enhanced CT by 50 % • ⁶⁸Ga-DOTA-TATE PET augments the accuracy of contrast-enhanced CT by 30 % • Somatostatin receptor-targeted hybrid imaging optimizes primary tumour detection in CUP-NET.

Relationship between glycemic control and coronary artery disease severity, prevalence and plaque characteristics by computed tomography coronary angiography in asymptomatic type 2 diabetic patients

Evaluate whether glycemic control in type 2 diabetes (DM2) asymptomatic for coronary artery disease (CAD) affects not only the presence and magnitude of CAD but also the characteristics of plaque vulnerability using multidetector row computed coronary tomography (MDCT). Acute coronary syndrome (ACS) is frequently observed in asymptomatic DM2 patients. Positive vessel remodeling (PR) and low-attenuation plaques (LAP) identified by MDCT have been demonstrated to be characteristics of subsequent culprit lesions of ACS. However, little is known regarding plaque characteristics in asymptomatic diabetic patients and their relationship with glycemic control. Ninety asymptomatic DM2 patients, aged 40-65 years old, underwent MDCT. The presence of atherosclerotic obstruction, defined as coronary stenosis ≥50 %, and plaque characteristics were compared between two groups of patients with A1c < 7 and A1c ≥ 7 %. Of the 90 patients, 38 (42.2 %) presented with coronary atherosclerotic plaques, 11 had A1c < 7 % and 27 had A1c ≥ 7 % (p = 0.0006). Fourteen patients had significant lumen obstruction higher than 50 %: 3 in the A1c < 7 % group and 11 in the A1c ≥ 7 % group (p = 0.02). Non-calcified plaque was more prevalent in the A1c ≥ 7 % group (p = 0.005). In eleven patients, the simultaneous presence of two vulnerability plaque characteristics (PR and LAP) were observed more frequently in the A1c ≥ 7 group (n = 8) than in the A1c < 7 group (n = 3) (p = 0.04). Asymptomatic DM2 patients with A1c ≥ 7 % have a higher frequency of CAD and a higher proportion of vulnerable atherosclerotic coronary plaque by MDCT compared to patients with DM2 with A1c < 7 in our study.

A retrospective, semi-quantitative image quality analysis of cone beam computed tomography (CBCT) and MSCT in the diagnosis of distal radius fractures

OBJECTIVE

To compare image quality and diagnostic validity of CBCT and MSCT for distal radius fractures.

METHODS

35 CBCT and 33 MSCT scans were retrospectively reviewed with a visual grading scale regarding the depiction of cortical bone, trabecular bone, articular surfaces, and soft tissue. The extent and type of artefacts was analyzed. Agreement on AO classification and measurement of cortical disruption and length of the fracture gap was determined. Fracture reduction was evaluated in post-treatment x-rays. Statistical analysis was performed with visual grading characteristics (VGC), chi square tests, and Kendall's coefficient of concordance.

RESULTS

CBCT performed significantly worse for cortical bone, articular surfaces, and especially soft tissue. Trabecular bone showed no significant difference. Significantly more CBCT images showed artefacts. Physics-based artefacts were the most common. CBCT scans also showed motion artefacts. There was no significant difference in agreement on AO classification. The agreement on measurements was substantial for both modalities. Slightly more fractures that had undergone MSCT imaging showed adequate reduction.

CONCLUSION

This initial study of an orthopaedic extremity CBCT scanner showed that the image quality of a CBCT scanner remains inferior for most structures at standard settings. Diagnostic validity of both modalities for distal radius fractures seems similar.

KEY POINTS

• Subjectively, CBCT remains inferior to MSCT in depicting most structures. • Similar diagnostic validity for CBCT and MSCT imaging of distal radius fractures. • CBCT is a possible alternative to MSCT in musculoskeletal imaging. • Visual grading characteristics (VGC) analysis proves useful in analyzing visual grading scales.

Morphometric analysis of stab wounds by MSCT and MRI after the instillation of contrast medium

OBJECTIVE

To analyze the morphology and depth of stab wounds experimentally produced on human legs amputated for medical reasons using multislice computed tomography (MSCT) and magnetic resonance imaging (MRI) after the instillation of a single contrast medium solution (CMS).

MATERIALS AND METHODS

For morphological analysis, MSCT and MRI scans were performed before and after the instillation of CMS into the wound cavity. Depth measurements were performed on the sagittal view only after CMS instillation. Subsequently, each wound was dissected using the layer-by-layer technique and the depth was measured by a ruler. One-way between-groups pairwise analysis of variance (ANOVA) and Bland-Altman plot analysis were used for comparing radiological and anatomical measurements.

RESULTS

Unenhanced MSCT images did not identify the wound channels, whereas unenhanced MRI evidenced the wound cavity in 50 % of cases. After the instillation of CMS, both MSCT and MRI depicted the wound channel in all the investigated stabbings, although the morphology of the cavity was irregular and did not resemble the shape of the blade. The radiological measurements of the wounds' depth, after the application of CMS, exhibited a high level of agreement (about 95 % at Bland-Altman plot analysis) with the anatomical measurements at dissection. A similar systematic underestimation, however, has been evidenced for MSCT (average 11.4 %; 95 % CI 7-17) and MRI (average 9.6 %; 95 % CI 6-13) data after the instillation of CMS with respect to wound dissection measurements.

CONCLUSION

MSCT and MRI after the instillation of CMS can be used for depicting the morphometric features of stab wounds, although depth measurements are affected by a slight systematic underestimation compared to layer-by-layer dissection.

MR-arthrography and CT-arthrography in sports-related glenolabral injuries: a matched descriptive illustration

The combination of a large range of motion and insufficient bony stabilization makes the glenohumeral joint susceptible to injuries including dislocation in young athletes. Magnetic resonance arthrography (MR-arthrography) and computed tomography arthrography (CT-arthrography) play an important role in the preoperative workup of labroligametous injuries. This paper illustrates MR-arthrography and CT-arthrography findings acquired at the same time on the same subjects to illustrate common causes and sequelae of shoulder instability. Teaching Points • MR-arthrography and CT-arthrography are equivalent for SLAP and full-thickness rotator cuff tears.• CT-arthrography is superior in evaluating osseous defects and cartilage surface lesions.• MR-arthrography is superior in evaluating intrasubstance and extra-articular tendinous injuries.

Oral and Maxillofacial Imaging

This article provides the reader with the knowledge and skills of identification and diagnostic interpretative skills using planar images, tomographic images, CBCT, MDCT, pertinent MR images, as well as bone scans and PET images. The goal is to provide sufficient in-depth knowledge of the technique, anatomy, and radiographic identifiers for the diagnosis of local and systemic pathoses. The information will train the reader to be an advocate of selection criteria as well as a follower of the "Image Gently" campaign and philosophy supported by the organized dentistry in the United States, especially in Diagnostic Radiology.

Implantable cardioverter-defibrillator in a patient with dextrocardia situs inversus

BACKGROUND

Dextrocardia is a congenital anomaly, which may have coexistent coronary artery disease (CAD), arrhythmias and conventional indications for device therapy. However, the implantation of transvenous leads can be technically challenging and the approach needs to be tailored to the patient's individual anatomy.

CASE PRESENTATION

A 54-year-old male with dextrocardia situs inversus and ischemic left ventricular dysfunction developed ventricular tachycardia and fibrillation. Therefore, left- sided approach, dual chamber implantable cardioverter-defibrillator (ICD) was applied using a conventional method and standard equipment after complete evaluation of cardiac anatomy and vascular assessment.

CONCLUSION

Electrical device implantation in patients with dextrocardia is possible after obtaining complete information about anatomy and/or coexisting congenital abnormalities, which helps in obtaining appropriate implantation approach.

Iodine concentration as a perfusion surrogate marker in oncology: Further elucidation of the underlying mechanisms using Volume Perfusion CT with 80 kVp

OBJECTIVES

To assess the value of iodine concentration (IC) in computed tomography data acquired with 80 kVp, as a surrogate for perfusion imaging in hepatocellular carcinoma (HCC) and lymphoma by comparing iodine related attenuation (IRA) with quantitative Volume Perfusion CT (VPCT)-parameters.

METHODS

VPCT-parameters were compared with intra-tumoral IC at 5 time points after the aortic peak enhancement (APE) with a temporal resolution of 3.5 sec in untreated 30 HCC and 30 lymphoma patients.

RESULTS

Intra-tumoral perfusion parameters for HCC showed a blood flow (BF) of 52.7 ± 17.0 mL/100 mL/min, blood volume (BV) 12.6 ± 4.3 mL/100 mL, arterial liver perfusion (ALP) 44.4 ± 12.8 mL/100 mL/min. Lesion IC 7 sec after APE was 133.4 ± 57.3 mg/100 mL. Lymphoma showed a BF of 36.8 ± 13.4 mL/100 mL/min, BV of 8.8 ± 2.8 mL/100 mL and IC of 118.2 ± 64.5 mg/100 mL 3.5 sec after APE. Strongest correlations exist for VPCT-derived BF and ALP with IC in HCC 7 sec after APE (r = 0.71 and r = 0.84) and 3.5 sec after APE in lymphoma lesions (r = 0.77). Significant correlations are also present for BV (r = 0.60 and r = 0.65 for HCC and lymphoma, respectively).

CONCLUSIONS

We identified a good, time-dependent agreement between VPCT-derived flow values and IC in HCC and lymphoma. Thus, CT-derived ICs 7 sec after APE in HCC and 3.5 sec in lymphoma may be used as surrogate imaging biomarkers for tumor perfusion with 80 kVp.

KEY POINTS

• Iodine concentration derived from low kVp CT is regarded as perfusion surrogate • Correlation with Perfusion CT was performed to elucidate timing and histology dependencies • Highest correlation was present 7 sec after aortic peak enhancement in hepatocellular carcinoma • In lymphoma, highest correlation was calculated 3.5 sec after aortic peak enhancement • With these results, further optimization of Dual energy CT protocols is possible.

Evaluation of diaphragm in penetrating left thoracoabdominal stab injuries: The role of multislice computed tomography

INTRODUCTION

Penetrating left thoracoabdominal stab injuries are accompanied by diaphragmatic injury in 25-30% of cases, about 30% of which later develop into diaphragmatic hernia. This study aimed to determine the role of multislice computed tomography in the evaluation of left diaphragm in patients with penetrating left thoracoabdominal stab wounds.

MATERIALS AND METHODS

This study reviewed penetrating left thoracoabdominal stab injuries managed in our clinic between April 2009 and September 2014. The thoracoabdominal region was defined as the region between the sternum, fourth intercostal space, and arcus costa anteriorly and the vertebra, lower tip of scapula, and the curve of the last rib posteriorly. Unstable cases and cases with signs of peritonitis were operated with laparotomy; the remaining patients were closely monitored. Forty-eight hours later, a diagnostic laparoscopy was applied to evaluate the left hemidiaphragma in asymptomatic patients who did not need laparotomy. The preoperatively obtained multislice thoracoabdominal computed tomography images were retrospectively examined for the presence of left diaphragm injury. Then, operative and tomographic findings were compared.

RESULTS

This study included a total of 43 patients, 39 (91%) males and 4 (9%) females of mean age 30 years (range 15-61 years). Thirty patients had normal tomography results, whereas 13 had left diaphragmatic injuries. An injury to the left diaphragm was detected during the operation in 9 (1 in laparotomy and 8 in diagnostic laparoscopy) of 13 patients with positive tomography for left diaphragmatic injury and 2 (in diagnostic laparoscopy) of 30 patients with negative tomography. Multislice tomography had a sensitivity of 82% (95% CI: 48-98%), a specificity of 88% (71-96%), a positive predictive value of 69% (39-91%), and a negative predictive value of 93% (78-99%) for detection of diaphragmatic injury in penetrating left thoracoabdominal stab injury.

CONCLUSIONS

Although diagnostic laparoscopy is the gold standard for diaphragmatic examination in patients with penetrating left thoracoabdominal stab wounds, multislice computed tomography is also valuable for detecting diaphragmatic injury.

T2 mapping of CT remodelling patterns in interstitial lung disease

OBJECTIVES

To evaluate lung T2 mapping for quantitative characterization and differentiation of ground-glass opacity (GGO), reticulation (RE) and honeycombing (HC) in usual interstitial pneumonia (UIP) and non-specific interstitial pneumonia (NSIP).

METHODS

Twelve patients with stable UIP or NSIP underwent thin-section multislice CT and 1.5-T MRI of the lung. A total of 188 regions were classified at CT into normal (n = 29) and pathological areas, including GGO (n = 48), RE (n = 60) and HC (n = 51) predominant lesions. Entire lung T2 maps based on multi-echo single shot TSE sequence (TE: 20, 40, 79, 140, 179 ms) were generated from each subject with breath-holds at end-expiration and ECG-triggering.

RESULTS

The median T2 relaxation of GGO was 67 ms (range 60-72 ms). RE predominant lesions had a median relaxation of 74 ms (range 69-79 ms), while for HC pattern this was 79 ms (range 74-89 ms). The median T2 relaxation for normal lung areas was 41 ms (ranged 38-49 ms), and showed significant difference to pathological areas (p < 0.001). A statistical difference was found between the T2 relaxation of GGO, RE and HC (p < 0.05).

CONCLUSIONS

The proposed method provides quantitative information for pattern differentiation, potentially allowing for monitoring of progression and response to treatment, in interstitial lung disease.

KEY POINTS

• Multi-echo single shot TSE sequence allows for entire lung T2 mapping. • Lung remodelling patterns in ILD show different T2 relaxation. • Quantitative T2 mapping may provide information for monitoring of ILD.

Magnetic resonance imaging-diffusion weighted imaging vs multi-slice computed tomography for preoprative typing and T-staging of gastric cancer

AIM: To compare the performance of magnetic resonance imaging-diffusion weighted imaging (MRI-DWI) and multislice computed tomography (MSCT) in preoperative typing and T-staging of gastric cancer.

METHODS: One hundred and two patients with pathologically confirmed gastric cancer who underwent either MSCT or MRI-DWI preoperatively at our hospital from November 2012 to August 2013 were included. Using pathologic results as the golden standard, the accuracy of MSCT and MRI-DWI for preoperative typing and T-staging of cancer were compared.

RESULTS: The accuracy of MRI-DWI in typing gastric cancer before surgery was 96.1%, which was significantly higher than that of MSCT (83.3%) (P < 0.01). The accuracy of MRI-DWI in T-staging of gastric cancer before surgery was 90.20% (92/102), which was significantly higher than that of MSCT (70.59%, 72/102) (P < 0.01). Interobserver consistency for MRI-DWI (Kappa = 0.813) was superior to that for MSCT (Kappa = 0.603).

CONCLUSION: The accuracy of MRI-DWI in preoperative typing and T-staging of gastric cancer is much higher than that of MSCT.

Viability assessment after conventional coronary angiography using a novel cardiovascular interventional therapeutic CT system: Comparison with gross morphology in a subacute infarct swine model

BACKGROUND

Given the lack of promptness and inevitable use of additional contrast agents, the myocardial viability imaging procedures have not been used widely for determining the need to performing revascularization.

OBJECTIVE

This study is aimed to evaluate the feasibility of myocardial viability assessment, consecutively with diagnostic invasive coronary angiography (ICA) without use of additional contrast agent, using a novel hybrid system comprising ICA and multislice CT (MSCT).

METHODS

In all, 14 Yucatan miniature swine models (female; age, 3 months; weight, 28-30 kg) were subjected to ICA followed by balloon occlusion (90 minutes) and reperfusion of the left anterior descending coronary artery. Two weeks after induction of myocardial infarction, delayed hyperenhancement (DHE) images were obtained, using a novel combined machine comprising ICA and 320-channel MSCT scanner (Aquilion ONE, Toshiba), after 2, 5, 7, 10, 15, and 20 minutes after conventional ICA. The heart was sliced in 10-mm consecutive sections in the short-axis plane and was embedded in a solution of 1% triphenyltetrazolium chloride (TTC). Infarct size was determined as TTC-negative areas as a percentage of total left ventricular area. On MSCT images, infarct size per slice was calculated by dividing the DHE area by the total slice area (%) and compared with histochemical analyses.

RESULTS

Serial MSCT scans revealed a peak CT attenuation of the infarct area (222.5 ± 36.5 Hounsfield units) with a maximum mean difference in CT attenuation between the infarct areas and normal myocardium of at 2 minutes after contrast injection (106.4; P for difference = 0.002). Furthermore, the percentage difference of infarct size by MSCT vs histopathologic specimen was significantly lower at 2 (8.5% ± 1.8%) and 5 minutes (9.5% ± 1.9%) than those after 7 minutes. Direct comparisons of slice-matched DHE area by MSCT demonstrated excellent correlation with TTC-derived infarct size (r = 0.952; P < .001). Bland-Altman plots of the differences between DHE by MSCT and TTC-derived infarct measurements plotted against their means showed good agreement between the 2 methods.

CONCLUSION

The feasibility of myocardial viability assessment by DHE using MSCT after conventional ICA was proven in experimental models, and the optimal viability images were obtained after 2 to 5 minutes after the final intracoronary injection of contrast agent for conventional ICA.

Evolution of cardiac imaging according to the number of scientific articles in medical journals: a long and fruitful journey

The use of cardiac imaging techniques as a diagnostic method in the understanding of physiopathology, as well as in cardiology research has been one of the most important revolutions in the management of cardiac patients, our understanding of physiopathology, and basic research in almost all heart diseases. This article analyzes the literature on echocardiography, cardiovascular magnetic resonance imaging, computed tomography, and nuclear medicine during the last 60 years and provides an overview of how these techniques have developed and how their introduction into daily practice has changed attitudes among cardiologists. The literature not only shows that the implementation of these techniques in daily practice requires an immense amount of research and effort by many working groups throughout the scientific world, but also that techniques that once seemed promising may finally be discarded.

Investigation of relation between visceral and subcutaneous abdominal fat volumes and calcified aortic plaques via multislice computed tomography

OBJECTIVE

The present study investigated effect of subcutaneous fat volume and abdominal visceral fat volume on aortic atherosclerosis via multislice computed tomography.

MATERIALS AND METHODS

The present study comprised 424 subjects who underwent non-contrast-enhanced abdominal CT in our clinic between June 2012 and June 2013. Using dedicated software visceral fat volume was calculated for each individual and then subcutaneous fat volume was calculated by subtracting visceral fat volume from total fat volume. By dividing visceral fat volume/subcutaneous fat volume participants were assigned to three groups according to their mean visceral fat volume/subcutaneous fat volume: Group 1 consisted of subjects with visceral fat volume/subcutaneous fat volume lower than 0.48 (Group 1 < 0.48); Group 2 consisted of subjects with visceral fat volume/subcutaneous fat volume equal to or higher than 0.48 and lower than 0.69 (0.48 ≤ Group 2 < 0.69); and Group 3 consisted of subjects with visceral fat volume/subcutaneous fat volume equal to or higher than 0.69 (Group 3 ≥ 0.69).

RESULTS

The mean abdominal aortic calcium scores according to Agatston scoring (au) were 136.8 ± 418.7 au in Group 1, 179.9 ± 463 au in Group 2 and 212.2 ± 486.9 in Group 3, respectively.

CONCLUSIONS

We have demonstrated a significant correlation between visceral fat volume and abdominal aorta atherosclerosis, while there was absence of significant correlation between subcutaneous fat volume and abdominal atherosclerosis.