Digital tomosynthesis for PNS evaluation: comparisons of patient exposure and image quality with plain radiography

Delta neutrophil index levels can be a good indicator to predict patients with chronic rhinosinusitis who need surgery

OBJECTIVES

Predicting the need for surgical treatment among patients with chronic rhinosinusitis (CRS) is challenging. The delta neutrophil index (DNI) has been proposed as a useful laboratory marker of immature granulocytes, which indicates infection or severe inflammation in several diseases. This study evaluated DNI as an early predictor of the need for surgery in patients with CRS.

METHODS

A total of 117 patients diagnosed with CRS were enrolled in this retrospective and observational study. Medical records, including symptoms data, WBC count, ESR level, LUC count, Lund-Mackay scores, and DNI, were reviewed. The receiver operating characteristic (ROC) curves were analyzed to determine the optimal cut-off values for predicting surgery.

RESULTS

Among 117 patients, 49 patients (41.9%) needed surgical intervention. The areas under the WBC, ESR, LUC, and DNI ROC curves were .571, .600, .592, and .782, respectively. The optimal cut-off value of DNI to predict surgery was .9%. The prognostic precision of DNI showed that the sensitivity was 59.2% and the specificity was 98.5%. In the analysis of risk factors, DNI levels were significantly associated with surgical intervention (odds ratio, 2.22; 95% confidence interval, 1.48-3.34; P < .01).

CONCLUSIONS

The level of DNI, which reflects the severity of the disease, may be a useful predictor for determining the need for surgical intervention in patients with CRS. This is the first literature to verify the role of DNI in upper airway disease.

Digital Tomosynthesis versus Conventional Radiography for Evaluating Osteonecrosis of the Femoral Head

Objective

The aim of this study was to compare the diagnostic performances of digital tomosynthesis (DTS) and conventional radiography in detecting osteonecrosis of the femoral head (ONFH) using computed tomography (CT), as the reference standard and evaluate the diagnostic reproducibility of DTS.

Materials and Methods

Forty-five patients (24 male and 21 female; age range, 25–77 years) with clinically suspected ONFH underwent anteroposterior radiography, DTS, and CT. Two musculoskeletal radiologists independently evaluated the presence and type of ONFH. The diagnostic performance of radiography and DTS in detecting the presence of ONFH and determining the types of ONFH were evaluated. The interobserver and intraobserver reliabilities of each imaging modality were analyzed using Cohen's kappa.

Results

DTS had higher sensitivity (89.4%–100% vs. 74.5%–76.6%) and specificity (97.3%–100% vs. 78.4%–83.8%) for ONFH detection than radiography. DTS showed higher performance than radiography in identifying the subtypes of ONFH with statistical significance in one reader (type 1, 100% vs. 30.8%, p = 0.004; type II, 97.1% vs. 73.5%, p = 0.008). The interobserver agreement was excellent for DTS and moderate for radiography (kappa of 0.86 vs. 0.57, respectively). The intraobserver agreement for DTS was higher than that of radiography (kappa of 0.96 vs. 0.69, respectively).

Conclusion

DTS showed higher diagnostic performance and reproducibility than radiography in detecting ONFH. DTS may be used as a first-line diagnostic modality instead of radiography for patients suspected of having ONFH.

Nasal Septal Deviation and Incidental Paranasal Sinus Opacification: A Role of Computed Tomography

Background and Objectives: The purpose of this study was to investigate the prevalence of incidental paranasal sinus (PNS) opacification in nasal septal deviation (NSD) using computed tomography (CT) and to identify contributing factors.Subjects and Method: We analyzed 216 patients who underwent septoplasty for the correction of NSD and who underwent preoperative PNS CT. We assessed the prevalence of incidental PNS opacification in these patients and determined the type of NSD according to Mladina classification. We also evaluated whether the direction of NSD affected the presence of PNS opacification on CT, and whether the presence of PNS opacification was associated with other rhinologic symptoms.Results: Of 216 patients with NSD, 86 showed opacified PNS on CT. According to Mladina classification, NSD patients were classified as type I (24.1%), type II (36.1%), type III (20.8%), type IV (5.6%), type V (9.7%), type VI (2.3%), or type VII (1.4%). Patients with type II NSD showed a significantly higher incidence of PNS opacification compared with other types of NSD (p=0.001). However, the direction of NSD did not significantly influence the presence of incidental PNS opacification. Furthermore, regardless of the presence of PNS opacification, there was no significant difference in rhinologic symptoms such as olfactory dysfunction, among others.Conclusion: We found that incidental PNS opacification on CT was common in NSD patients, especially in patients with type II NSD. Thus, we suggest that CT evaluation of patients with NSD may be helpful for assessing comorbid PNS pathologies as well as objectively identifying nasal septal deformities.

Incidence and Radiological Findings of Incidental Sinus Opacifications in Patients Undergoing Septoplasty or Septorhinoplasty

OBJECTIVES

Although the routine use of computed tomography (CT) is controversial, it is employed in the preoperative screening of patients undergoing septoplasty or septorhinoplasty. The aim of this study was to evaluate the incidence and radiological characteristics of incidentally found sinus pathologies on screening CT in patients who underwent elective septoplasty or septorhinoplasty.

METHODS

We retrospectively reviewed the patients who underwent septoplasty and septorhinoplasty performed by a single surgeon (Y.J.J.) at Asan Medical Center between January 2016 and December 2017. CT images of 372 patients who had agreed to undergo preoperative CT were reviewed to determine the location and extent of incidental sinus opacifications.

RESULTS

Of the 372 patients, 107 (28.8%) showed incidental sinus lesions on CT images. Opacifications were mainly found in the maxillary sinus (73, 68.2%), followed by the ethmoid (34, 31.8%), sphenoid (10, 9.3%), and frontal (3, 2.8%) sinuses. The most common sinus lesion was retention cyst (55, 51.4%), and the second most common one was opacification and mucosal thickening (46, 43%). Other lesions such as osteoma (3, 2.8%), dental cyst (2, 1.9%), and mucocele (1, 0.9%) were rarely found.

CONCLUSIONS

In patients undergoing septoplasty or septorhinoplasty, the incidence of incidental sinus lesions was approximately 28.8% (107/372). This results indicate that preoperative CT in patients undergoing septoplasty or septorhinoplasty might be helpful to surgeons not only for better understanding the anatomical detail but also for detecting hidden paranasal sinus disease.

Selection and Reporting of Statistical Methods to Assess Reliability of a Diagnostic Test: Conformity to Recommended Methods in a Peer-Reviewed Journal

Objective

To evaluate the frequency and adequacy of statistical analyses in a general radiology journal when reporting a reliability analysis for a diagnostic test.

Materials and Methods

Sixty-three studies of diagnostic test accuracy (DTA) and 36 studies reporting reliability analyses published in the Korean Journal of Radiology between 2012 and 2016 were analyzed. Studies were judged using the methodological guidelines of the Radiological Society of North America-Quantitative Imaging Biomarkers Alliance (RSNA-QIBA), and COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) initiative. DTA studies were evaluated by nine editorial board members of the journal. Reliability studies were evaluated by study reviewers experienced with reliability analysis.

Results

Thirty-one (49.2%) of the 63 DTA studies did not include a reliability analysis when deemed necessary. Among the 36 reliability studies, proper statistical methods were used in all (5/5) studies dealing with dichotomous/nominal data, 46.7% (7/15) of studies dealing with ordinal data, and 95.2% (20/21) of studies dealing with continuous data. Statistical methods were described in sufficient detail regarding weighted kappa in 28.6% (2/7) of studies and regarding the model and assumptions of intraclass correlation coefficient in 35.3% (6/17) and 29.4% (5/17) of studies, respectively. Reliability parameters were used as if they were agreement parameters in 23.1% (3/13) of studies. Reproducibility and repeatability were used incorrectly in 20% (3/15) of studies.

Conclusion

Greater attention to the importance of reporting reliability, thorough description of the related statistical methods, efforts not to neglect agreement parameters, and better use of relevant terminology is necessary.

Radiation Dose Reduction in Paranasal Sinus CT: With Feasibility of Iterative Reconstruction Technique

OBJECTIVES

To (1) compare the radiation dose of low-dose computed tomography (CT) to that of standard-dose CT, (2) determine the minimum optimal radiation dose for use in patients who need endoscopic sinus surgery, and (3) assess the reliability of iterative model reconstruction.

STUDY DESIGN

Prospective single-institution study.

SETTING

Tertiary care center.

SUBJECTS AND METHODS

We recruited 48 adults with medically refractory sinusitis. Each patient underwent 4 scans with different CT parameters: 120 kV and 100 mAs (standard dose), 100 kV and 40 mAs (low dose), 100 kV and 20 mAs (very low dose), and 100 kV and 10 mAs (ultra-low dose). All CT scans were reconstructed via filtered back-projection, and ultra-low dose scans were additionally reconstructed through iterative model reconstruction. Radiation dose, image quality, and diagnostic performance were compared among the scans.

RESULTS

Radiation doses decreased to 6% (ultra-low dose), 12% (very low dose), and 22% (low dose) of the standard-dose CT. The image quality of low-dose CT was similar to that of standard-dose CT. Ultra-low-dose CT with iterative model reconstruction was inferior to standard-dose CT for identifying anatomic structures, except for the optic nerve. All CT scans had 100% agreement for diagnosing rhinosinusitis.

CONCLUSIONS

With low-dose CT, the radiation dose can be decreased to 22% of that of standard-dose CT without affecting the image quality. Low-dose CT can be considered the minimum optimal radiation for patients who need surgery. Iterative model reconstruction is not useful for assessing the anatomic details of the paranasal sinus on CT.

Does the Reporting Quality of Diagnostic Test Accuracy Studies, as Defined by STARD 2015, Affect Citation?

Objective

To determine the rate with which diagnostic test accuracy studies that are published in a general radiology journal adhere to the Standards for Reporting of Diagnostic Accuracy Studies (STARD) 2015, and to explore the relationship between adherence rate and citation rate while avoiding confounding by journal factors.

Materials and Methods

All eligible diagnostic test accuracy studies that were published in the Korean Journal of Radiology in 2011–2015 were identified. Five reviewers assessed each article for yes/no compliance with 27 of the 30 STARD 2015 checklist items (items 28, 29, and 30 were excluded). The total STARD score (number of fulfilled STARD items) was calculated. The score of the 15 STARD items that related directly to the Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 was also calculated. The number of times each article was cited (as indicated by the Web of Science) after publication until March 2016 and the article exposure time (time in months between publication and March 2016) were extracted.

Results

Sixty-three articles were analyzed. The mean (range) total and QUADAS-2-related STARD scores were 20.0 (14.5–25) and 11.4 (7–15), respectively. The mean citation number was 4 (0–21). Citation number did not associate significantly with either STARD score after accounting for exposure time (total score: correlation coefficient = 0.154, p = 0.232; QUADAS-2-related score: correlation coefficient = 0.143, p = 0.266).

Conclusion

The degree of adherence to STARD 2015 was moderate for this journal, indicating that there is room for improvement. When adjusted for exposure time, the degree of adherence did not affect the citation rate.

Multi-Institutional Evaluation of Digital Tomosynthesis, Dual-Energy Radiography, and Conventional Chest Radiography for the Detection and Management of Pulmonary Nodules

Purpose To conduct a multi-institutional, multireader study to compare the performance of digital tomosynthesis, dual-energy (DE) imaging, and conventional chest radiography for pulmonary nodule detection and management. Materials and Methods In this binational, institutional review board-approved, HIPAA-compliant prospective study, 158 subjects (43 subjects with normal findings) were enrolled at four institutions. Informed consent was obtained prior to enrollment. Subjects underwent chest computed tomography (CT) and imaging with conventional chest radiography (posteroanterior and lateral), DE imaging, and tomosynthesis with a flat-panel imaging device. Three experienced thoracic radiologists identified true locations of nodules (n = 516, 3-20-mm diameters) with CT and recommended case management by using Fleischner Society guidelines. Five other radiologists marked nodules and indicated case management by using images from conventional chest radiography, conventional chest radiography plus DE imaging, tomosynthesis, and tomosynthesis plus DE imaging. Sensitivity, specificity, and overall accuracy were measured by using the free-response receiver operating characteristic method and the receiver operating characteristic method for nodule detection and case management, respectively. Results were further analyzed according to nodule diameter categories (3-4 mm, >4 mm to 6 mm, >6 mm to 8 mm, and >8 mm to 20 mm). Results Maximum lesion localization fraction was higher for tomosynthesis than for conventional chest radiography in all nodule size categories (3.55-fold for all nodules, P < .001; 95% confidence interval [CI]: 2.96, 4.15). Case-level sensitivity was higher with tomosynthesis than with conventional chest radiography for all nodules (1.49-fold, P < .001; 95% CI: 1.25, 1.73). Case management decisions showed better overall accuracy with tomosynthesis than with conventional chest radiography, as given by the area under the receiver operating characteristic curve (1.23-fold, P < .001; 95% CI: 1.15, 1.32). There were no differences in any specificity measures. DE imaging did not significantly affect nodule detection when paired with either conventional chest radiography or tomosynthesis. Conclusion Tomosynthesis outperformed conventional chest radiography for lung nodule detection and determination of case management; DE imaging did not show significant differences over conventional chest radiography or tomosynthesis alone. These findings indicate performance likely achievable with a range of reader expertise. ^© RSNA, 2016 Online supplemental material is available for this article.

Total aplasia of the paranasal sinuses

Although a variety of theories have been proposed about functions of the paranasal sinuses, not one is clear today. Nonetheless, paranasal sinus–related diseases are associated with a high rate of morbidities. Therefore, it is essential to identify the structure and pathophysiology of the paranasal sinuses. Computed tomography (CT) is a valuable tool displaying anatomic variations and diseases. Because paranasal sinus development is a complex and long-lasting process, there are great structural variations between individuals. Several degrees and combinations of aplasias and hypoplasias have been reported; however, there is only one case of total paranasal sinus aplasia in the literature. Here, we present the second case of total paranasal sinus aplasia. Paranasal sinus development, functions of the paranasal sinuses, and the role of CT were evaluated.

Digital tomosynthesis of the chest: comparison of patient exposure dose and image quality between standard default setting and low dose setting

Objective

To determine the optimum low dose (LD) digital tomosynthesis (DT) setting, and to compared the image quality of the LD DT with that of the standard default (SD) DT.

Materials and Methods

Nine DT settings, by changing tube voltage, copper filter, and dose ratio, were performed for determining the LD setting. Among combinations of DT setting, a condition providing the lowest radiation dose was determined. Eighty artificial nodules less than 1 cm in diameter (subcentimeter nodules: 40, micronodules less than 4 mm: 40) were attached to a Styrofoam and a diaphragm of the phantom. Among these, 38 nodules were located at the periphery of the lung (thin area) and 42 nodules were located at the paravertebral or sub-diaphragmatic area (thick area). Four observers counted the number of nodules detected in the thick and thin areas. The detection sensitivity in SD and LD settings were calculated separately. Data were analyzed statistically.

Results

The lowest LD setting was a combination of 100 kVp, 0.3 mm additional copper filter, and a 1 : 5 dose ratio. The effective dose for the LD and SD settings were 62 µSv and 140 µSv, separately. A 56.7% dose reduction was achieved in the LD setting compared with the SD setting. Detection sensitivities were not different between the SD and the LD settings except between observers 1 and 2 for the detection of micronodules in the thick area.

Conclusion

LD DT can be effective in nodule detection bigger than 4 mm without a significant decrease in image quality compared with SD DT.