Intermodality Agreement Research Articles

Usefulness of high-resolution three-dimensional proton density-weighted turbo spin-echo MRI in distinguishing a junctional dilatation from an intracranial aneurysm of the posterior communicating artery: a pilot study

BackgroundDiscriminating a junctional dilatation from a true saccular aneurysm is clinically important.PurposeTo evaluate the usefulness of high-resolution three-dimensional proton density-weighted turbo spin-echo magnetic resonance imaging (PD MRI) in distinguishing a...

Ferumoxytol-enhanced MRI for surveillance of pediatric cerebral arteriovenous malformations.

Children with intracranial arteriovenous malformations (AVMs) undergo digital DSA for lesion surveillance following their initial diagnosis. However, DSA carries risks of radiation exposure, particularly for the growing pediatric brain and over lifetime. The authors evaluated whether MRI enhanced with a blood pool ferumoxytol (Fe) contrast agent (Fe-MRI) can be used for surveillance of residual or recurrent AVMs. A retrospective cohort was assembled of children with an established AVM diagnosis who underwent surveillance by both DSA and 3-T Fe-MRI from 2014 to 2016. Two neuroradiologists blinded to the DSA results independently assessed Fe-enhanced T1-weighted spoiled gradient recalled acquisition in steady state (Fe-SPGR) scans and, if available, arterial spin labeling (ASL) perfusion scans for residual or recurrent AVMs. Diagnostic confidence was examined using a Likert scale. Sensitivity, specificity, and intermodality reliability were determined using DSA studies as the gold standard. Radiation exposure related to DSA was calculated as total dose area product (TDAP) and effective dose. Fifteen patients were included in this study (mean age 10 years, range 3-15 years). The mean time between the first surveillance DSA and Fe-MRI studies was 17 days (SD 47). Intermodality agreement was excellent between Fe-SPGR and DSA (κ = 1.00) but poor between ASL and DSA (κ = 0.53; 95% CI 0.18-0.89). The sensitivity and specificity for detecting residual AVMs using Fe-SPGR were 100% and 100%, and using ASL they were 72% and 100%, respectively. Radiologists reported overall high diagnostic confidence using Fe-SPGR. On average, patients received two surveillance DSA studies over the study period, which on average equated to a TDAP of 117.2 Gy×cm2 (95% CI 77.2-157.4 Gy×cm2) and an effective dose of 7.8 mSv (95% CI 4.4-8.8 mSv). Fe-MRI performed similarly to DSA for the surveillance of residual AVMs. Future multicenter studies could further investigate the efficacy of Fe-MRI as a noninvasive alternative to DSA for monitoring AVMs in children.

CT Angiography in Occlusion Assessment of Intracranial Aneurysms Treated with the WEB Device.

Capabilities of CTA for evaluation of intracranial aneurysms treated with the Woven EndoBridge (WEB) system has not been thoroughly studied yet. Our aim is to compare the ability of CTA to that of DSA to depict the occlusion status of aneurysms treated with WEB device and present the level of reproducibility of results from CTA. Patients with intracranial aneurysm treated only with the WEB device and having a CTA and a DSA during the same hospital stay were included. Aneurysm occlusion was evaluated by two methods: a simplified binomial system grading as either adequate occlusion (complete occlusion or neck remnant) or aneurysm remnant and a four-grade scale. Interobserver and intermodality agreement were determined using the κ statistic. Using DSA as a reference test, the diagnostic capabilities of CTA were calculated. Sixteen patients with 16 aneurysms were included. Interobserver agreement was fair for DSA (κ = .26) and good for CTA (κ = .78) using the four-grade scale, and moderate for DSA (κ = .44) and good for CTA (κ = .63) using the binomial scale. CTA and DSA were in agreement in 15 of 16 aneurysms (93.75%) using the binomial scale meaning good intermodality agreement for aneurysm remnant detection (κ = .63). Sensitivity of CTA for detection of an aneurysm remnant was 50%, specificity was 100%, positive prediction value was 100%, and negative prediction value was 93.33%. CTA is a reliable and reproducible method to evaluate the aneurysm occlusion status and could be implemented on the follow-up of aneurysms treated with WEB.

Susceptibility-Weighted Angiography for the Follow-Up of Brain Arteriovenous Malformations Treated with Stereotactic Radiosurgery.

The criterion standard for assessing brain AVM obliteration postradiosurgery is DSA. To explore the value of susceptibility-weighted angiography, we followed 26 patients with brain AVMs treated by radiosurgery using susceptibility-weighted angiography and DSA. Studies were evaluated by 2 independent readers for residual nidi. Susceptibility-weighted angiography demonstrated good intermodality (κ = 0.71) and interobserver (κ = 0.64) agreement, and good sensitivity (85.7%) and specificity (85.7%). Susceptibility-weighted angiography is a useful radiation- and contrast material-free technique to follow-up brain AVM obliteration postradiosurgery.

Pointwise Encoding Time Reduction with Radial Acquisition with Subtraction-Based MRA during the Follow-Up of Stent-Assisted Coil Embolization of Anterior Circulation Aneurysms.

Time-of-flight MR angiography, though widely used after coil embolization, is associated with limitations owing to magnetic susceptibility and radiofrequency shielding following stent-assisted coil embolization. We evaluated the pointwise encoding time reduction with radial acquisition (PETRA) sequence in subtraction-based MRA (qMRA) using an ultrashort TE relative to TOF-MRA during the follow-up of stent-assisted coil embolization for anterior circulation aneurysms. Twenty-five patients (3 men and 22 women; mean age, 59.1 ± 14.0 years) underwent stent-assisted coil embolization for anterior circulation aneurysms and were retrospectively evaluated using TOF-MRA and PETRA qMRA data from the same follow-up session. Two neuroradiologists independently reviewed both MRA findings and subjectively graded flow within the stents (relative to the latest DSA findings) and occlusion status (complete occlusion or neck/aneurysm remnant). Interobserver and intermodality agreement for TOF-MRA and PETRA qMRA were evaluated. The mean score for flow visualization within the stents was significantly higher in PETRA qMRA than in TOF-MRA (P < .001 for both observers), and good interobserver agreement was reported (κ = 0.63). The aneurysm occlusion status of PETRA qMRA (observer 1, 92.0%; observer 2, 88.0%) was more consistent with DSA than with TOF-MRA (observer 1, 76.0%; observer 2, 80.0%), and there was a better intermodality agreement between DSA and PETRA qMRA than between DSA and TOF-MRA. These findings indicate that PETRA qMRA is a useful follow-up technique for patients who have undergone stent-assisted coil embolization for anterior circulation aneurysms.

A Comparison Among Different Automatically Segmented Slabs to Assess Neovascular AMD using Swept Source OCT Angiography.

PurposeWe systematically compare the intermodality and interreader agreement in age-related macular degeneration(AMD)-associated neovascularization assessment for optical coherence tomography angiography (OCTA) images obtained using different slabs.MethodsWe collected data from 48 patients (50 eyes) with type 1 or 2 neovascularization (NV) and AMD. Subjects were imaged with a swept source (SS)-OCTA system. For each eye, three OCTA en face images generated from three different slabs were exported: (1) the outer retina to choriocapillaris (ORCC) image, (2) the choriocapillaris (CC) image, and (3) the retinal pigment epithelium (RPE)-RPE fit image. Each image was graded by two readers to assess interreader variability and a single image for each modality was used to assess the intermodality variability.ResultsIn the assessment of type 1 NV, mean absolute interreader difference between measured NV areas was 0.19, 0.30, and 0.16 mm2 for ORCC, CC, and RPE-RPE fit images, respectively. Similarly, the coefficient of repeatability (CR) and intraclass correlation coefficient (ICC) indicated that the RPE-RPE fit assessment was characterized by the highest interreader reproducibility. Type 1 NV size was 0.58 mm2 (0.30–1.60 mm2) on ORCC images, 0.00 mm2 (0.00–0.36 mm2) on CC images (P = 0.002 vs. ORCC), and 0.62 mm2 (0.31–2.03 mm2) on RPE-RPE fit images (P < 0.0001 vs. CC, P = 0.041 vs. ORCC).ConclusionsThe RPE-RPE fit OCTA images have the highest interreader agreement and deliver larger measurements in type 1 lesions.Translational RelevanceOCTA imaging may be used in ongoing trials of potential novel treatments for NV.

Semi-automated quantification of geographic atrophy with blue-light autofluorescence and spectral-domain optical coherence tomography: a comparison between the region finder and the advanced retinal pigment epithelium tool in the clinical setting.

PurposeTo compare inter‐ and intraobserver reliability and intermodality agreement on quantification of geographic atrophy, using two routinely available quantification tools, based on blue‐light fundus autofluorescence (BAF) and spectral‐domain optical coherence tomography (SD‐OCT).MethodsQuantifications of atrophic lesions within the central 5 mm of 30 eyes from 30 patients (mean age: 76.1 years) were independently performed by two clinicians on BAF images using the region finder (RF; Heidelberg Engineering) and on SD‐OCT using the advanced retinal pigment epithelium tool (ARPET; Carl Zeiss Meditec) at baseline and follow‐up (mean interval: 336 days). Inter‐ and intraobserver reliability was determined by intraclass correlation coefficients (ICC) and Bland–Altmann plots. Additionally, graders rated the experienced difficulty of each measurement.ResultsIntraclass correlation coefficients (ICC) showed excellent inter‐ and intraobserver reliability with values between 0.994 and 0.998 for RF and slightly higher values for ARPET of 0.997 and 0.999. Bland–Altman plots showed smaller variability for ARPET. Mean interobserver differences (95% CI) for size measurements were −0.11 (−0.27; 0.05) (baseline) and −0.05 mm² (−0.18; 0.08) (follow‐up) for RF and −0.04 (−0.14; 0.06) and −0.06 mm² (−0.14; 0.02) for ARPET. Measurements of lesions were on average 0.57 mm² (0.35; 0.79) or 7.6% larger in ARPET. Lesion size between graders did not differ significantly. There was no statistically significant difference in relative enlargement rates between methods. There was poor to moderate agreement between graders when rating the experienced difficulty of each measurement.ConclusionSemi‐automated analysis of geographic atrophy with RF and ARPET is equally reliable and reproducible in clinical settings, despite both algorithms require frequent adjustment by users. The ARPET restricts size measurements to the central 5 mm, which limits its ability to fully track GA progression. Results of both tools are not interchangeable as measurements with ARPET result in larger lesion sizes.

Cervical Spine CT Using Spectral Shaping: Can It Be a Solution to Overcome Artifacts in the Lower Cervical Spinal Region?

To investigate the image quality, radiation dose, and intermodality agreement of cervical spine CT using spectral shaping at 140 kVp by a tin filter (Sn140-kVp) in comparison with those of conventional CT at 120 kVp. Patients who had undergone cervical spine CT with Sn140-kVp (n = 58) and conventional 120 kVp (n = 49) were included. Qualitative image quality was analyzed using a 5-point Likert scale. Quantitative image quality was assessed by measuring the noise and attenuation within the central spinal canals at C3/4, C6/7, and C7/T1 levels. Radiation doses received by patients were estimated. The intermodality agreement for disc morphology between CT and MRI was assessed at C3/4, C5/6, C6/7, and C7/T1 levels in 75 patients who had undergone cervical spine MRI as well as CT. Qualitative image quality was significantly superior in Sn140-kVp scans than in the conventional scans (p < 0.001). At C7/T1 level, the noise was significantly lower and the decrease in attenuation was significantly less in Sn140-kVp scans, than in the conventional scans (p < 0.001). Radiation doses were significantly reduced in Sn140-kVp scans by 50% (effective dose: 1.0 ± 0.1 mSv vs. 2.0 ± 0.4 mSv; p < 0.001). Intermodality agreement in the lower cervical spine region tended to be better in Sn140-kVp acquisitions than in the conventional acquisitions. Cervical spine CT using Sn140-kVp improves image quality of the lower cervical region without increasing the radiation dose. Thus, this protocol can be helpful to overcome the artifacts in the lower cervical spine CT images.

Agreement in Histological Assessment of Mitotic Activity Between Microscopy and Digital Whole Slide Images Informs Conversion for Clinical Diagnosis

Validating digital pathology as substitute for conventional microscopy in diagnosis remains a priority to assure effectiveness. Intermodality concordance studies typically focus on achieving the same diagnosis by digital display of whole slide images and conventional microscopy. Assessment of discrete histological features in whole slide images, such as mitotic figures, has not been thoroughly evaluated in diagnostic practice. To further gauge the interchangeability of conventional microscopy with digital display for primary diagnosis, 12 pathologists examined 113 canine naturally occurring mucosal melanomas exhibiting a wide range of mitotic activity. Design reflected diverse diagnostic settings and investigated independent location, interpretation, and enumeration of mitotic figures. Intermodality agreement was assessed employing conventional microscopy (CM40×), and whole slide image specimens scanned at 20× (WSI20×) and at 40× (WSI40×) objective magnifications. An aggregate 1647 mitotic figure count observations were available from conventional microscopy and whole slide images for comparison. The intraobserver concordance rate of paired observations was 0.785 to 0.801; interobserver rate was 0.784 to 0.794. Correlation coefficients between the 2 digital modes, and as compared to conventional microscopy, were similar and suggest noninferiority among modalities, including whole slide image acquired at lower 20× resolution. As mitotic figure counts serve for prognostic grading of several tumor types, including melanoma, 6 of 8 pathologists retrospectively predicted survival prognosis using whole slide images, compared to 9 of 10 by conventional microscopy, a first evaluation of whole slide image for mitotic figure prognostic grading. This study demonstrated agreement of replicate reads obtained across conventional microscopy and whole slide images. Hence, quantifying mitotic figures served as surrogate histological feature with which to further credential the interchangeability of whole slide images for primary diagnosis.

MRI versus CT: Which Modality Is Better in Gross Tumor Volume Delineation for External Beam Radiotherapy in Cancer Patients? A Systematic Review and Meta-Analysis

Background: are a variety of imaging modalities for contouring the GTV of EBRT that strive for more accurate delineation and better concordance between observers. Nowadays, there is a great controversy about which modality (MRI or CT) is more accurate for GTV delineation. We conducted a systematic review and meta-analysis to investigate whether MRI or CT is better in GTV delineation for EBRT in cancer patients. Methods: We identified MRI, CT and GTV studies by searching PubMed, Embase and the Cochrane Library databases until April 18, 2019. We included original articles reporting GTV delineation using CT and MRI. The outcomes of interest included GTV, interobserver agreement (IOA) and intermodality agreement (IMA) among different modalities (MRI only, MRI+CT fusion, CT). The accuracy of GTV delineation of these imaging modalities was compared with pathology (path). The MD or SMD and their corresponding 95% CIs were selected as the effect size. Subgroup and sensitivity analyses were performed. Findings: Thirty-two studies encompassing 672 participants (677 lesions) were included. We did not identify any significant difference between GTVMRI only / GTVMRI+CT fusion and GTVCT (SMD: -0.02, 95% CI: -0.20~0.17, P=0.84; SMD:0.53, 95% CI: -0.22~1.28, P=0.17 respectively). GTVCT was larger than GTVpath (SMD:0.92, 0.26~1.58, P=0.006), whereas no difference was observed when MRI only was compared with path (SMD:0.71, -0.36~1.78, P=0.19). No significant difference was observed between the IOA of MRI only / MRI+CT fusion and CT (MD: 0.00, -0.09~0.08, P=0.92; MD: 0.03, -0.01~0.08, P=0.14, respectively). Subgroup analysis showed that GTVMRI+CT fusion was significantly larger for the delineation of nasopharyngeal cancer (NPC) (SMD: 6.83, 5.89~7.78, P<0.001). MRI only had the highest tumor coverage by comparing with path (Mean:0.88, 0.82~0.94), followed by CT (Mean:0.85, 0.79~0.91). Only the IMA of MRI only versus MRI+CT fusion showed good concordance (Mean:0.84, 0.79~0.89) among the three pairs composed of three images (MRI only, MRI+CT fusion, and CT); all others showed moderate concordance. Interpretation: CT, MRI only and MRI+CT fusion for GTV delineation are all clinically applicable for preoperative adjuvant radiotherapy. Prospective studies emphasizing the collection of patient-reported data and functional follow-ups are strongly recommended. Funding Statement: The authors state: There was no funding source for this study. Declaration of Interests: The authors declare: None. Ethics Approval Statement: The authors declare: Not applicable. The authors conducted this systematic review and meta-analysis in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The study protocol was registered with PROSPERO (Number CRD4209127649).

Echocardiography and cardiovascular magnetic resonance based evaluation of myocardial strain and relationship with late gadolinium enhancement

ObjectivesWe sought to: (1) determine the agreement in cardiovascular magnetic resonance (CMR) and speckle tracking echocardiography (STE) derived strain measurements, (2) compare their reproducibility, (3) determine which approach is best related to CMR late gadolinium enhancement (LGE).BackgroundWhile STE-derived strain is routinely used to assess left ventricular (LV) function, CMR strain measurements are not yet standardized. Strain can be measured using dedicated pulse sequences (strain-encoding, SENC), or post-processing of cine images (feature tracking, FT). It is unclear whether these measurements are interchangeable, and whether strain can be used as an alternative to LGE.MethodsFifty patients underwent 2D echocardiography and 1.5 T CMR. Global longitudinal strain (GLS) was measured by STE (Epsilon), FT (NeoSoft) and SENC (Myocardial Solutions) and circumferential strain (GCS) by FT and SENC.ResultsGLS showed good inter-modality agreement (r-values: 0.71–0.75), small biases (< 1%) but considerable limits of agreement (− 7 to 8%). The agreement between the CMR techniques was better for GLS than GCS (r = 0.81 vs 0.67; smaller bias). Repeated measurements showed low intra- and inter-observer variability for both GLS and GCS (intraclass correlations 0.86–0.99; coefficients of variation 3–13%). LGE was present in 22 (44%) of patients. Both SENC- and FT-derived GLS and GCS were associated with LGE, while STE-GLS was not. Irrespective of CMR technique, this association was stronger for GCS (AUC 0.77–0.78) than GLS (AUC 0.67–0.72) and STE-GLS (AUC = 0.58).ConclusionThere is good inter-technique agreement in strain measurements, which were highly reproducible, irrespective of modality or analysis technique. GCS may better reflect the presence of underlying LGE than GLS.

Cerebral Perfusion Territory Changes After Direct Revascularization Surgery in Moyamoya Disease: A Territory Arterial Spin Labeling Study

To use territory arterial spin labeling (T-ASL) in the early postoperative period to evaluate the revascularization area (RA) obtained by superficial temporal artery-to-middle cerebral artery bypass and to evaluate subsequent perfusion territory changes of the major cerebral arteries. Thirty patients with moyamoya disease treated via unilateral superficial temporal artery-to-middle cerebral artery bypass were included. T-ASL was performed preoperatively and within 1 week postoperatively. The RA was examined by labeling the superficial temporal artery-to-middle cerebral artery bypass postoperatively. Preoperative and postoperative perfusion territories of the bilateral internal carotid arteries, bilateral external carotid arteries, and basilar artery were also examined and compared. Postoperative computed tomography angiography was performed and compared with T-ASL results. In 14 of 30 patients (46.7%), T-ASL demonstrated the presence of an RA (RA-positive), whereas 16 patients (53.3%) had no RA (RA-negative). In the RA-positive group, mean volume of the RA was 80.32 ± 8.13 mL (range, 34.95-142.50 mL). Postoperative perfusion territory changes of the major cerebral arteries differed between the RA-positive group and the RA-negative group. The incidence of preoperative external carotid artery compensation was significantly higher in the RA-negative group than the RA-positive group (F= 0.011, df = 1, P < 0.05). There was good intermodality agreement between T-ASL and computed tomography angiography (κ= 0.780). T-ASL can demonstrate the RA obtained by direct revascularization and postoperative perfusion territory changes of the major cerebral arteries. T-ASL is a promising technique in postoperative evaluation of patients with moyamoya disease.

Evaluation of osseous cervical foraminal stenosis in spinal radiculopathy using susceptibility-weighted magnetic resonance imaging.

The aim of this study was to evaluate the diagnostic performance of susceptibility-weighted magnetic resonance imaging (SW-MRI) for the evaluation of osseous foraminal stenosis (FS) of the cervical spine compared to conventional MRI-sequences, using computed tomography (CT) as a reference standard. Twenty-one patients with suspected radiculopathy of the cervical spine were prospectively included. CT and MRI data sets were available for all patients. As standard of reference, 280 neuroforamina of the cervical spine, including 58 foraminal stenosis, were identified on sagittal CT images. T1-, T2-, and SW-MRI of the cervical spine were performed. The presence of foraminal stenosis was assessed on sagittal views in all sequences. Sensitivity and specificity were calculated and differences in detection rate and severity scoring of foraminal stenosis between the different sequences were tested. CT was used as reference standard for all analysis. Fifty-six of 58 osseous foraminal stenosis could be correctly identified on SW-MR magnitude images. SW-MRI achieved a sensitivity of 96.6% and specificity of 99.5% for the identification of foraminal stenosis. In comparison, conventional T1-weighted MRI sequences achieved a sensitivity and specificity of 43.1% and 100% respectively. T2-weighted MRI sequences achieved a sensitivity and specificity of 65.5% and 99.1%, respectively. The overall detection rate was significantly (p < 0.05) higher on SW-MRI and there was no significant difference (p > 0.05) in severity scoring compared to CT. T1- and T2-weighted MRI underestimated the degree of foraminal stenosis. Intermodality and interobserver agreements were highest for SW-MRI. SW-MRI enables the reliable detection of osseous foraminal stenosis of the cervical spine in patients with spinal radiculopathy with a higher sensitivity compared to conventional T1- and T2-MRI sequences, with CT as a reference standard. • Susceptibility-weighted magnetic resonance imaging enables the reliable detection of osseous foraminal stenosis of the cervical spine with CT as a reference standard. • This could be relevant for younger patients in order to prevent unnecessary radiation exposure. • This may also facilitate a one-stop-shop approach and speed up diagnostic work-up.

Comparison of Green Versus Blue Fundus Autofluorescence in ABCA4-Related Retinopathy.

PurposeTo investigate the interreader and intermodality agreement for grading of retinal pigment epithelium (RPE) atrophy lesion size in ABCA4-related retinopathy using green (GAF) and blue fundus autofluorescence (BAF) imaging.MethodsIn this cross-sectional case series, 97 eyes of 49 patients with RPE atrophy secondary to ABCA4-related retinopathy underwent GAF- (518 nm excitation light) and BAF- (488 nm excitation light) imaging using confocal scanning laser ophthalmoscopy (Spectralis HRA, Heidelberg Engineering, Heidelberg, Germany). Lesions with definitely decreased autofluorescence (DDAF) and questionably decreased autofluorescence (QDAF) in GAF and BAF imaging were analyzed separately by five independent readers using semiautomated software (RegionFinder, Heidelberg Engineering). Intermodality and interreader agreements were assessed for the square-root lesion size, lesion perimeter, and circularity.ResultsGAF- and BAF-based measurements of DDAF and QDAF showed high intermodality and interreader agreement concerning square-root lesion size, as well as shape descriptive parameters (perimeter and circularity). Interreader agreement of square-root lesion size was slightly, hence not significantly higher for GAF-based grading ([95% coefficients of repeatability, intraclass correlation coefficient] DDAF: 0.215 mm, 0.997; QDAF: 0.712 mm, 0.981) compared to BAF-based grading (DDAF: 0.232 mm, 0.997; QDAF: 0.764 mm, 0.978). However, DDAF-measurements revealed distinctly more reproducible results than QDAF-measurements. Foveal sparing did not interfere with intermodality agreement.ConclusionsBoth GAF- and BAF-based quantification of RPE atrophy showed very reliable results with possible superiority of GAF in the context of less energetic excitation light.Translational RelevanceThe high interreader agreement qualifies the use of DDAF progression in GAF and BAF imaging as potential morphologic outcome measure for interventional clinical trials and disease monitoring.

Computed tomography or contrast-enhanced ultrasonography for follow-up of liver metastases after Cyberknife therapy?: A prospective pilot study.

Contrast-enhanced ultrasonography (CEUS) allows the study of vascularization of secondary liver lesions. The Cyberknife (Accuray, Inc, Sunnyvale, CA) is a therapeutic method that allows a tumor target to be subjected to a high radiant dose gradient. This prospective pilot study aimed to demonstrate the concordance of CEUS versus contrast-enhanced computed tomography (CECT) in determining the stability or disease progression of secondary liver lesions after treatment with the Cyberknife. Twenty-four patients were consecutively enrolled, and 3 different operators evaluated the CEUS images and the intermodality concordance with CECT. All patients received CEUS at 1 and 2 months after the Cyberknife therapy. The intermodality agreement was evaluated by the Cohen κ coefficient and a multivariate analysis according to the method of Janson and Olsson (Educ Psychol Meas 2001; 61:277-289). Forty secondary liver lesions were detected and treated. Forty-one CECT and 51 CEUS examinations were performed without any adverse events in the 24 patients. The intermodality agreement rates, calculated for the operators as Cohen κ values, were κ = 1.00, 0.881, and 0.767, respectively. The multivariate analysis of intermodality agreement showed an almost perfect value (ι = 0.841). This pilot study found excellent diagnostic correspondence between CEUS and CECT in the evaluation of local disease stability or progression after Cyberknife therapy in liver metastases. These findings suggest that CEUS could play an important role in the surveillance of these patients because of its high accuracy and reproducibility, thus reducing the need for CECT.

Comparative assessment of qualitative and quantitative perfusion with dual-energy CT and planar and SPECT-CT V/Q scanning in patients with chronic thromboembolic pulmonary hypertension.

The purpose of this study was to compare the qualitative and quantitative assessment of perfusion on dual-energy CT (DECT) and planar and single photon emission computed tomography (SPECT)-CT V/Q scanning in patients with chronic thromboembolic pulmonary hypertension (CTEPH). Nineteen patients with known CTEPH underwent both DECT and SPECT-CT V/Q scanning. Sixteen of these patients underwent planar V/Q imaging concurrently. Two readers independently graded DECT-perfused blood volume (PBV) defects on a four-point scale (0= normal, 1= mild <25%, 2= moderate 25-50%, 3= severe >50%). A grade was given for each lung lobe and for each of 18 lung segments. One reader graded the SPECT-CT images similarly. Quantitative measurements of lung perfusion were calculated with DECT and planar V/Q scanning for 16 of these patients. The inter-reader agreement on DECT was strong with agreement in 85% (258/304) of segments (kappa =0.86) and 84% (80/95) of lobes (kappa =0.82). The inter-modality agreement between DECT and SPECT-CT was lower. Readers 1 and 3 agreed in only 34% (103/304) of segments (kappa =0.25) and 33% (31/94) of lobes (kappa =0.22). Agreement between readers 2 and 3 was similar. Correlation between quantitative measurements with DECT and planar V/Q imaging was poor and ranged from 0.01 to 0.45. Inter-observer agreement in subjective grading of PBV maps is excellent. However, inter-modality agreement between DECT and SPECT-CT is modest. Automated quantification values of PBV maps correlate poorly with established tools like planar V/Q imaging. These differences need to be kept in mind during clinical decision making.

Point vs. traditional method evaluation of hallux valgus: interreader reliability and intermethod performance using X-ray and MRI.

The two most widely used measurements for diagnosing and assessing the severity of hallux valgus are the hallux valgus angle (HVA) and the intermetatarsal angle (IMA). Traditionally, these have been measured by using the midaxial lines approximating the axis of each bone. A new simpler point method has been recently suggested for measuring these angles by connecting points along the medial corners of each bone. Interreader reliability of these measurements on X-ray and MRI as well as intermethod and intermodality differences have not been assessed. A series of 56 consecutive patients between 18 and 100years old with no history of foot trauma or orthopedic hardware in their feet were included. All had AP and lateral X-rays and MRI performed on the same foot between April 27, 2015 and March 9, 2016. Two readers measured HVA and IMA using both the traditional midaxial and new point methods. ICC correlations were obtained. The interreader reliability for HVA was similar on point method (0.92) and traditional method (0.94). For the IMA, the ICC was 0.77 on point method versus 0.76 on traditional method. The intermodality agreement (between X-ray and MRI) was higher for HVA (ICC = 0.85, 0.88) as compared to IMA (0.58, 0.74), respectively on both methods. The mean difference between the methods was larger on traditional method = 5.5 for HVA and 2.5° for IMA. HVA is more reliable than IMA on both methods and modalities and a significant difference exists between the magnitudes of values obtained using the two methods. 3.

Usefulness of contrast-enhanced and TOF MR angiography for follow-up after low-profile stent-assisted coil embolization of intracranial aneurysms.

Low-profile, self-expandable stents are used to treat wide-neck aneurysms located on the smaller distal intracranial arteries. This study aimed to assess the usefulness of time-of-flight (TOF) and contrast-enhanced (CE) magnetic resonance angiography (MRA) for follow-up after LEO Baby stent (LBS)-assisted coil embolization. Twenty-four aneurysms treated with LBS-assisted coil embolization were evaluated. Researchers reviewed TOF MRA and CE MRA images in terms of occlusion and stent patency. Aneurysm occlusion was graded according to Raymond-Roy classification as follows: total occlusion (grade 1), residual neck (grade 2), and residual aneurysm (grade 3). Stent patency was scored as follows: occlusion (1), stenosis (2), and normal (3). Interobserver and intermodality agreement values were determined by weighted kappa (κ) statistics. Intermodality and interobserver values of TOF MRA and CE MRA with digital subtraction angiography (DSA) were perfect (κ = 1.00, p < 0.001) in terms of aneurysm occlusion. Rate of stent occlusion and stenosis in DSA, TOF, and MRA, respectively, were as follows: 0 and 12.5%, 16.6 and 70.8%, and 0 and 62.5%. Intermodality agreement values of TOF MRA and CE MRA with DSA were insignificant in terms of stent patency (κ = 0.065, p = 0.27; κ = 0.158, p = 0.15, respectively). Interobserver agreement was substantial in both TOF MRA (κ = 0.71, p < 0.001) and CE MRA (κ = 0.64, p = 0.001). Both TOF and CE MRA techniques have strong concordance with DSA for the detection of aneurysm occlusion status. CE MRA can be used as a first-line noninvasive imaging modality due to its superiority to TOF MRA with respect to the visualization of in-stent signals.

Comparison of short-wavelength blue-light autofluorescence and conventional blue-light autofluorescence in geographic atrophy

Background/aimsTo systematically compare the intermodality and inter-reader agreement for two blue-light confocal fundus autofluorescence (FAF) systems.MethodsThirty eyes (21 patients) with a diagnosis of geographic atrophy (GA) were enrolled. Eyes were...

Monitoring Cerebral Perfusion Changes after Revascularization in Patients with Moyamoya Disease by Using Arterial Spin-labeling MR Imaging.

Purpose To determine whether arterial spin-labeling (ASL) magnetic resonance (MR) imaging could be used to identify changes in cerebral blood flow (CBF), collateral blood flow, and anastomosis site patency after revascularization in patients with moyamoya disease. Materials and Methods This retrospective study was conducted in 145 patients with moyamoya disease who underwent middle cerebral artery (MCA)-superficial temporal artery anastomosis. Preoperative, early postoperative, and late postoperative ASL and digital subtraction angiography images were analyzed. In the MCA territory, absolute CBF (hereafter, CBFMCA) and normalized CBF values adjusted to nonanastomosis side (hereafter, nCBFMCA) and to cerebellum (hereafter, nCBFCbll) were calculated. Collateral grading in the MCA territory was assessed according to Alberta Stroke Program Early CT Score methodology, and anastomosis site patency were also assessed. Changes in CBF were compared by using one-way analysis of variance with Bonferroni correction for multiple comparisons. Intermodality agreement was determined by κ statistics. Results Significant increases in CBFMCA, nCBFMCA, and nCBFCbll were found after revascularization (preoperative and postoperative values of CBFMCA, 35.2 mL/100 g per minute ± 7.8 [mean ± standard deviation] and 51.5 mL/100 g per minute ± 12.0; nCBFMCA, 0.73 mL/100 g per minute ± 0.14 and 1.01 mL/100 g per minute ± 0.18; nCBFCbll, 0.74 mL/100 g per minute ± 0.12 and 1.12 mL/100 g per minute ± 0.16; all P < .001). Agreements for collateral grading and anastomosis patency between ASL MR imaging and digital subtraction angiography were moderate to good, with weighted κ values of 0.77 (95% confidence interval: 0.73, 0.81) and 0.57 (95% confidence interval: 0.37, 0.76), respectively. Conclusion ASL MR imaging can be used to identify perfusion changes in patients with moyamoya disease after revascularization as a noninvasive monitoring tool.