Thin-slab Maximum Intensity Projection Research Articles

Dedicated Photon-Counting CT for Detection and Classification of Microcalcifications: An Intraindividual Comparison With Digital Breast Tomosynthesis.

Clinical experience regarding the use of dedicated photon-counting breast CT (PC-BCT) for diagnosis of breast microcalcifications is scarce. This study systematically compares the detection and classification of breast microcalcifications using a dedicated breast photon-counting CT, especially designed for examining the breast, in comparison with digital breast tomosynthesis (DBT). This is a prospective intraindividual study on women with DBT screening-detected BI-RADS-4/-5 microcalcifications who underwent PC-BCT before biopsy. PC-BCT images were reconstructed with a noninterpolated spatial resolution of 0.15 × 0.15 × 0.15 mm (reconstruction mode 1 [RM-1]) and with 0.3 × 0.3 × 0.3 mm (reconstruction mode 2 [RM-2]), plus thin-slab maximum intensity projection (MIP) reconstructions. Two radiologists independently rated the detection of microcalcifications in direct comparison with DBT on a 5-point scale. The distribution and morphology of microcalcifications were then rated according to BI-RADS. The size of the smallest discernible microcalcification particle was measured. For PC-BCT, the average glandular dose was determined by Monte Carlo simulations; for DBT, the information provided by the DBT system was used. Between September 2022 and July 2023, 22 participants (mean age, 61; range, 42-85 years) with microcalcifications (16 malignant; 6 benign) were included. In 2/22 with microcalcifications in the posterior region, microcalcifications were not detectable on PC-BCT, likely because they were not included in the PC-BCT volume. In the remaining 20 participants, microcalcifications were detectable. With high between-reader agreement (κ > 0.8), conspicuity of microcalcifications was rated similar for DBT and MIPs of RM-1 (mean, 4.83 ± 0.38 vs 4.86 ± 0.35) (P = 0.66), but was significantly lower (P < 0.05) for the remaining PC-BCT reconstructions: 2.11 ± 0.92 (RM-2), 2.64 ± 0.80 (MIPs of RM-2), and 3.50 ± 1.23 (RM-1). Identical distribution qualifiers were assigned for PC-BCT and DBT in 18/20 participants, with excellent agreement (κ = 0.91), whereas identical morphologic qualifiers were assigned in only 5/20, with poor agreement (κ = 0.44). The median size of smallest discernible microcalcification particle was 0.2 versus 0.6 versus 1.1 mm in DBT versus RM-1 versus RM-2 (P < 0.001), likely due to blooming effects. Average glandular dose was 7.04 mGy (PC-BCT) versus 6.88 mGy (DBT) (P = 0.67). PC-BCT allows reliable detection of in-breast microcalcifications as long as they are not located in the posterior part of the breast and allows assessment of their distribution, but not of their individual morphology.

“Transcallosal” periventricular anastomosis in moyamoya disease: the fourth periventricular anastomosis and a potential predictor of hemorrhage

ObjectivesChoroidal anastomosis is a risk factor for hemorrhage in moyamoya disease. One variant of choroidal anastomosis, “transcallosal anastomosis,” originates from the medial posterior choroidal artery, and penetrates the corpus callosum to reconstruct the pericallosal artery. We aimed to investigate the prevalence and the bleeding rate of transcallosal anastomosis using sliding thin-slab maximum intensity projection reformatted from magnetic resonance angiography (MRA). Materials and MethodsThis study included 222 patients. We defined transcallosal anastomosis grades (0-2) and the stenosis of the anterior (ACA, 0-2), middle (MCA, 1-3), and posterior cerebral artery (PCA, 0-2) by MRA scores, independently by two coauthors. ResultsGrade-2 transcallosal anastomosis was detected in 21 patients (9.5 %). There were no correlations of the incidence of transcallosal anastomosis with previous bypass surgery (P = 0.23). Multivariate analysis revealed a significantly higher incidence in hemorrhagic onset and younger age (odds ratio [OR] 3.77, and 0.97). Transcallosal anastomosis had statistically significant correlation with ACA and PCA scores (P = 0.01 and 0.03), but not with MCA scores (P = 0.1). In multivariate analysis, ACA scores 1 and 2 were significantly higher (OR, 15.44 and 11.17), and PCA score 1 was also higher (OR, 3.07), but PCA score 2 was not. Interrater agreement for judgment of transcallosal anastomosis grade was strong (κ = 0.89). Two patients with Grade-2 transcallosal anastomosis had late hemorrhage in the corpus callosum (bleeding rate: 2.5 % per year). ConclusionsTranscallosal anastomosis may be associated with both advanced ACA and moderate PCA stenosis, and cause hemorrhage at the corpus callosum.

Thin-slab maximum intensity projection of CT angiography for collateral score and clot burden score evaluation: comparison with conventional CT angiography.

This study aimed to exam the effects of thin-slab maximum intensity projection (TS-MIP) of computed tomography angiography (CTA) for collateral score (CS) and clot burden score (CBS) evaluation in patients with large-vessel-occlusion (LVO) stroke in the anterior circulation. Of 241 consecutive patients with LVO stroke admitted to our center between August 2015 and June 2020, 187 patients were enrolled. CS and CBS were evaluated on conventional CTA and TS-MIP separately. Outcome at 90 days was classified as good if modified Rankin scale (mRS) was ≤2 and as poor if mRS was >2. The correlations between CS and CBS and clinical outcomes were assessed. Receiver operating characteristic (ROC) curve analysis was used to determine the diagnostic values of CS and CBS. Multivariate logistic regression analysis was performed to identify the independent predictors of 90-day good clinical outcomes. The correlation coefficient for clinical outcomes was significantly better for CS based on TS-MIP than that based on conventional CTA (-0.444 vs. -0.285, P=0.039); no significant difference was found in the CBS evaluation (TS-MIP: -0.356 vs. conventional CTA: -0.320, P=0.348). For predicting good clinical outcomes, TS-MIP-based CS was associated with larger area under the curve (AUC) (0.709 vs. 0.609, P=0.004) and higher sensitivity (69.1% vs. 42.0%, P=0.001) than CS based on CTA. In multivariable logistic regression analysis, the factors independently associated with good outcomes were National Institutes of Health Stroke Scale (NIHSS) score at admission (OR =1.147; P<0.001), TS-MIP-based CS (OR =0.326; P<0.001), final modified treatment in cerebral infarction (mTICI) score of 2b/3 (OR =0.098; P<0.001), and hemorrhagic transformation (OR =3.662; P<0.001). TS-MIP-CTA is superior to conventional CTA for evaluation CS and CBS, and TS-MIP-based CS may be a useful predictor of clinical outcome.

Practical utilization of cardiac computed tomography for the success in complex coronary intervention.

Percutaneous coronary intervention (PCI) for complex lesions is still technically demanding and is associated with less favorable procedural parameters such as lower success rate, longer procedural time, higher contrast volume and unexpected complications. Because the conventional angiographic analysis is limited by the inability to visualize the plaque information and the occluded segment, cardiac computed tomography has evolved as an adjunct to invasive angiography to better characterize coronary lesions to improve success rates of PCI. Adding to routine image reconstructions by coronary computed tomography angiography, the thin-slab maximum intensity projection method, which is a handy reconstruction technique on an ordinary workstation, could provide easy-to-understand images to reveal the anatomical characteristics and the lumen and plaque information simultaneously, and then assist to build an in-depth strategy for PCI. Especially in the treatment of chronic total occlusion lesion, these informations have big advantages in the visualization of the morphologies of entry and exit, the occluded segment and the distribution of calcium compared to invasive coronary angiography. Despite of the additional radiation exposure, contrast use and cost for cardiac computed tomography, the precise analysis of lesion characteristics would consequently improve the procedural success and prevent the complication in complex PCI.

Visualization of Thrombus Enhancement on Thin-Slab Maximum Intensity Projection of CT Angiography: An Imaging Sign for Predicting Stroke Source and Thrombus Compositions.

Background Thrombus enhancement (TE) in large vessel occlusion in patients with acute ischemic stroke can be visualized with thin-slab maximum intensity projection (TS-MIP) image reconstruction of CT angiograms. Purpose To evaluate whether TE on TS-MIP reconstructed CT angiograms can be used to predict thrombus composition and stroke source. Materials and Methods This retrospective study included consecutive patients with acute ischemic stroke who underwent thrombectomy in the anterior circulation between August 2016 and July 2019. Stroke types were classified according to the Trial of ORG 10172 in Acute Stroke Treatment. TE on TS-MIP reconstructed CT angiograms was evaluated by two readers. Various clinical and interventional parameters and histopathologic thrombi examination results were compared between the TE-positive and TE-negative groups. The associations between TE and thrombus compositions and stroke sources were analyzed by using multivariable linear and logistic regression models. Results A total of 148 patients (mean age, 71 years ± 11 [standard deviation]; 94 men) were included. TE was confirmed in 80% (119 of 148) of the patients. TE-positive thrombi contained a higher fibrin and platelet proportion (mean, 46% ± 16 vs 34% ± 13; P = .02) and fewer erythrocytes (mean, 33% ± 14 vs 48% ± 20, P = .002) than the TE-negative thrombi. The proportion of cardioembolic and cryptogenic strokes in the TE-positive and TE-negative groups was 92% (110 of 119) and 24% (seven of 29), respectively (P < .001). In adjusted analysis, the presence of TE (odds ratio, 155; 95% CI: 17, 1438; P < .001) was associated with a combination of cardioembolic and cryptogenic strokes. A multiple logistic regression model showed that TE (odds ratio, 23; 95% CI: 1.8, 288; P = .02) was significantly associated with cardioembolic stroke. Conclusion Thrombus enhancement on thin-slab maximum intensity projection of CT angiography can be used to predict cardioembolic and cryptogenic strokes and identify thrombi with a higher fibrin-to-platelet fraction and a lower erythrocyte proportion. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Kansagra and Goyal in this issue.

Cognitive Impairment and Lamina Cribrosa Thickness in Primary Open-Angle Glaucoma.

PurposeThe purpose of this study was to investigate the relationship between the lamina cribrosa (LC) thickness (LCT) as assessed using enhanced depth-imaging (EDI) optical coherence tomography (OCT) and cognitive function in primary open-angle glaucoma (POAG).MethodsThe study consisted of 105 POAG eyes and 23 nonglaucomatous control eyes that completed neuropsychological tests. The optic nerve heads of the patients were imaged using EDI-OCT. B-scan images were constructed in three dimensions using maximum intensity projection (MIP), and the LCT was measured using the thin-slab MIP images. A comprehensive battery consisting of 15 neuropsychological tests was used to evaluate cognitive function.ResultsPOAG eyes had smaller mean LCT as compared with control eyes (P < 0.001). Age and Mini Mental State Examination (MMSE) scores did not differ between the two groups. Linear regression analysis revealed that lower scores on the MMSE (P < 0.001), presence of glaucoma (P = 0.006), and a smaller global retinal nerve fiber layer thickness (P < 0.001) were independently associated with a smaller mean LCT. Davies’ test revealed a statistically significant breakpoint for the mean LCT (221.14 µm), below which a smaller MMSE score was significantly associated with a smaller mean LCT. In POAG eyes with a mean LCT smaller than the breakpoint (< 221.14 µm), not only the global cognition but also the visuospatial function and visual memory were worse than in those with a larger mean LCT (all P ≤ 0.003).ConclusionsImpairment of cognitive function was observed in patients with POAG with a thinner LC. The role of LC imaging as a potential biomarker to monitor cognitive impairment needs further investigation.Translational RelevanceLC thinning may reflect a shared mechanism of neurodegenerative diseases in the brain and optic nerve.

A simple and software-independent protocol for the measurement of post-cranial bones in anthropological contexts using thin slab maximum intensity projection

Abstract Objective This paper introduces a new protocol for the measurement of post-cranial bones in computed tomography using slab maximum intensity projection. Materials and Methods The steps of the protocol are described and illustrated. Repeatability and accuracy are established through inter and intra observer testing evaluated using TEM, rTEM, and R. Results The protocol performed well in both repeatability and accuracy testing. Conclusion The protocol yields highly repeatable and accurate measurements.

CMed: Crowd Analytics for Medical Imaging Data.

We present a visual analytics framework, CMed, for exploring medical image data annotations acquired from crowdsourcing. CMed can be used to visualize, classify, and filter crowdsourced clinical data based on a number of different metrics such as detection rate, logged events, and clustering of the annotations. CMed provides several interactive linked visualization components to analyze the crowd annotation results for a particular video and the associated workers. Additionally, all results of an individual worker can be inspected using multiple linked views in our CMed framework. We allow a crowdsourcing application analyst to observe patterns and gather insights into the crowdsourced medical data, helping him/her design future crowdsourcing applications for optimal output from the workers. We demonstrate the efficacy of our framework with two medical crowdsourcing studies: polyp detection in virtual colonoscopy videos and lung nodule detection in CT thin-slab maximum intensity projection videos. We also provide experts' feedback to show the effectiveness of our framework. Lastly, we share the lessons we learned from our framework with suggestions for integrating our framework into a clinical workflow.

Personalized 3D printed coronary models in coronary stenting

3D printing has shown great promise in cardiovascular disease, with reports mainly focusing on pre-surgical planning and medical education. Research on utilization of 3D printed models in simulating coronary stenting has not been reported. In this study, we presented our experience of placing coronary stents into personalized 3D printed coronary models with the aim of determining stent lumen visibility with images reconstructed with different postprocessing views and algorithms. A total of six coronary stents with diameter ranging from 2.5 to 4.0 mm were placed into 3 patient-specific 3D printed coronary models for simulation of coronary stenting. The 3D printed models were placed in a plastic container and scanned on a 192-slice third generation dual-source CT scanner with images reconstructed with soft (Bv36) and sharp (Bv59) kernel algorithms. Thick and thin slab maximum-intensity projection (MIP) images were also generated from the original CT data for comparison of stent lumen visibility. Stent lumen diameter was measured on 2D axial and MIP images, while stent diameter was measured on 3D volume rendering images. 3D virtual intravascular endoscopy (VIE) images were generated to provide intraluminal views of the coronary wall and stent appearances. All of these stents were successfully placed into the right and left coronary arteries but 2 of them did not obtain wall apposition along the complete length. The stent lumen visibility ranged from 54 to 97%, depending on the stent location in the coronary arteries. The mean stent lumen diameters measured on 2D axial, thin and thick slab MIP images were found to be significantly smaller than the actual size (P<0.01). Thick slab MIP images resulted in measured stent lumen diameters smaller than those from thin slab MIP images, with significant differences noticed in most of the measurements (4 out of 6 stents) (P<0.05), and no significant differences in the remaining 2 stents (P=0.19-0.38). In contrast, 3D volume rendering images allowed for more accurate measurements with measured stent diameters close to the actual dimensions in most of these coronary stents, except for the stent placed at the right coronary artery in one of the models due to insufficient expansion of the stent. Images reconstructed with sharp kernel Bv59 significantly improved stent lumen visibility when compared to the smooth Bv36 kernel (P=0.01). 3D VIE was successfully generated in all of the datasets with clear visualization of intraluminal views of the stents in relation to the coronary wall. This preliminary report shows the feasibility of using 3D printed coronary artery models in coronary stenting for investigation of optimal coronary CT angiography protocols. Future studies should focus on placement of more stents with a range of stent diameters in the quest to reduce the need for invasive angiography for surveillance.

Application of degree of portal systemic shunting in assessing upper gastrointestinal bleeding in patients with schistosomiasis cirrhosis

To discuss the application of the degree of portal systemic shunting in assessing the upper gastrointestinal bleeding in patients with hepatic schistosomiasis. Thirty-three patients with upper gastrointestinal bleeding caused by hepatic schistosomiasis (a bleeding group) and 29 schistosomiasis cirrhosis patients without bleeding (a non-bleeding group) were enrolled as investigation subjects in Jinshan Hospital. The subjects were scanned by the 128 abdominal slice spiral CT. The portal systemic shunting vessels were reconstructed by using thin slab maximum intensity projection (TSMIP) and multiplanar reconstruction (MPR). The degrees of the shunting vessels of the subjects were evaluated and compared, and the relationship between upper gastrointestinal bleeding and the degree of the shunting was analyzed. In the bleeding group, the occurrence rates of the shunting vessels were found as follows: 86.4% in left gastric varices, 68.2% in short gastric varices, 50.0% in esophageal varices, 50.0% in para-esophageal varices, 37.9% in gastric varices, 69.7% in gastric-renal varices, 51.5% in spleen-renal varices, 25.8% in abdominal wall varices, 15.2% in omentum varices, 63.6% in para-splenic varices, 34.8% in umbilical varices, 40.9% in retroperitoneal-paravertebral varices, and 36.4% in mesenteric varices. In the bleeding group, the occurrence rates and the degree of shunt were significantly higher than those in the non-bleeding group in esophageal varices, esophageal vein, left gastric vein and gastric varices (all P < 0.05). CT portal vein reconstruction can accurately display the location, degree and walking of all kinds of shunting vessels. Esophageal varices, esophageal vein, left gastric vein and gastric varices can accurately predict the risk of upper gastrointestinal bleeding in patients with hepatic schistosomiasis. The patents with higher degree of the shunting vessels have a higher risk of gastrointestinal bleeding.

Three-dimensional contrast-enhanced magnetic resonance angiography for anterolateral thigh flap outlining: A retrospective case series of 68 patients.

Flap transfer is increasingly used for repairing limb defects secondary to trauma or tumor, and appropriate preoperative planning plays a critical role. The present study aimed to examine the use of three-dimensional (3D) contrast-enhanced magnetic resonance angiography (CE-MRA) in evaluating the blood supply distribution and perforating branch pattern of anterolateral thigh (ALT) flaps. Bilateral donor lower limbs were scanned in 68 patients (136 limbs) using a Siemens Avanto 1.5 T magnetic resonance imaging scanner with a 3D fast low-angle shot sequence, following the thin-slab maximum intensity projection (TS-MIP) technique. The lateral femoral circumflex artery (LFCA) was visualized in all patients: 101 limbs (101/136, 74.3%) were type I; 20 limbs (20/136, 14.7%) were type II; 3 limbs (3/136, 2.2%) were type III; and 12 limbs (12/136, 8.8%) were type IV. Tertiary branches were identified in 94 limbs (94/136, 69.1%). Donor flaps were outlined according to MRA TS-MIP findings in 4 patients. All flaps survived uneventfully following the transfer. In donor flap outlining, 3D CE-MRA with the TS-MIP technique allowed an accurate, direct visualization of the branching pattern and distribution profile of the LFCA supplying the ALT flap.

Increased CSF tau level is correlated with decreased lamina cribrosa thickness.

BackgroundThis study was to investigate whether the previously proposed link between Alzheimer’s disease (AD) and decreased retinal nerve fiber layer thickness could be explained by the relationship between abnormal CSF profiles and optic nerve head characteristics, focusing on the influence of CSF tau protein on the lamina cribrosa (LC) thickness (LCT).MethodsA total of 44 eyes from 18 patients with AD and 26 healthy subjects were subjected to enhanced-depth-imaging volume scanning of the optic nerve using spectral-domain optical coherence tomography. The B-scan images were constructed three-dimensionally using maximum intensity projection (MIP), and the LCT was measured at three locations (superior midperipheral, midhorizontal, and inferior midperipheral) using the thin-slab MIP images. CSF levels of amyloid β 1-42 peptide, (Aβ1–42), total tau (T-tau) and tau phosphorylated at threonine 181 (P-tau181P) were measured from CSF samples of each subject. The relationship between the level of CSF proteins and the LCT was determined using linear regression and fractional polynomial analyses.ResultsUnivariate regression analysis revealed that higher CSF levels of T-tau (P = 0.004) and P-tau181P (P = 0.027), as well as a smaller central corneal thickness (P = 0.032), were significantly associated with a smaller LCT. Multivariate analysis indicated that only CSF T-tau (P = 0.041) was significantly associated with the LCT. The relationship was well explained by both linear regression (R2 = 0.179, P = 0.004) and fractional polynomial analysis (R2 = 0.275, P = 0.001). When we performed an assessment by linear regression with an indicator, the relationship was significant both in the healthy and AD groups, with a stronger correlation found in the healthy group (regression coefficients = -1.098 vs. -0.280, P = 0.018).ConclusionsAn increased CSF level of T-tau was significantly associated with a thinner LCT in both the healthy and AD groups. This result suggests that LCT could serve as a potential non-invasive indicator for increased CSF tau. The clinical meaning of the higher level of CSF T-tau in axonal degeneration of the optic nerve remains to be determined.

Lung nodule and cancer detection in computed tomography screening.

Fundamental to the diagnosis of lung cancer in computed tomography (CT) scans is the detection and interpretation of lung nodules. As the capabilities of CT scanners have advanced, higher levels of spatial resolution reveal tinier lung abnormalities. Not all detected lung nodules should be reported; however, radiologists strive to detect all nodules that might have relevance to cancer diagnosis. Although medium to large lung nodules are detected consistently, interreader agreement and reader sensitivity for lung nodule detection diminish substantially as the nodule size falls below 8 to 10 mm. The difficulty in establishing an absolute reference standard presents a challenge to the reliability of studies performed to evaluate lung nodule detection. In the interest of improving detection performance, investigators are using eye tracking to analyze the effectiveness with which radiologists search CT scans relative to their ability to recognize nodules within their search path in order to determine whether strategies might exist to improve performance across readers. Beyond the viewing of transverse CT reconstructions, image processing techniques such as thin-slab maximum-intensity projections are used to substantially improve reader performance. Finally, the development of computer-aided detection has continued to evolve with the expectation that one day it will serve routinely as a tireless partner to the radiologist to enhance detection performance without significant prolongation of the interpretive process. This review provides an introduction to the current understanding of these varied issues as we enter the era of widespread lung cancer screening.

Reduction in Observation Unit Length of Stay With Coronary Computed Tomography Angiography Depends on Time of Emergency Department Presentation

Prior studies demonstrating shorter length of stay (LOS) from coronary computed tomography angiography (CCTA) relative to stress testing in emergency department (ED) patients have not considered time of patient presentation. The objectives of this study were to determine whether low-risk chest pain patients receiving stress testing or CCTA have differences in ED plus observation unit (OU) LOS and if there are disparities in testing modality use, based on the time of patient presentation to the ED. The authors examined a cohort of low-risk chest pain patients evaluated in an ED-based OU using prospective and retrospective OU registry data. During the study period, stress testing and CCTA were both available from 08:00 to 17:00 hours. CCTA was not available on weekends, and therefore only subjects presenting on weekdays were included. Cox regression analysis was used to model the effect of testing modality (stress testing vs. CCTA) on OU LOS. Separate models were fit based on time of patient presentation to the ED using 4-hour blocks beginning at midnight. The primary independent variable was testing modality: stress testing or CCTA. Age, sex, and race were included as covariates. Logistic regression was used to model testing modality choice by time period adjusted for age, sex, and race. Over the study period, 841 subjects presented Monday through Friday. Median LOS was 18.0 hours (interquartile range [IQR] = 11.7 to 22.9 hours). Objective cardiac testing was completed in 788 of 841 (94%) patients, with 496 (63%) receiving stress testing and 292 (37%) receiving CCTA. After age, race, and sex were adjusted for, patients presenting between 08:00 and 11:59 hours not only had a shorter LOS associated with CCTA (p < 0.0001), but also had a greater likelihood of being tested by CCTA (p = 0.001). None of the other time periods had significant differences in LOS or testing modality choice for CCTA relative to stress testing. In an OU setting with weekday and standard business hours CCTA availability, CCTA testing was associated with shorter LOS among low-risk chest pain patients only in patients presenting to the ED between 08:00 and 11:59 hours. That time period was also associated with a greater likelihood of being tested by CCTA, suggesting that ED providers may have intuited the inability of CCTA to shorten LOS during other times.

Improved Reproducibility in Measuring the Laminar Thickness on Enhanced Depth Imaging SD-OCT Images Using Maximum Intensity Projection

To investigate whether the thin-slab maximum intensity projection (MIP) image improves the reproducibility of the measurement of spectral domain optical coherence tomography (SD-OCT) based lamina cribrosa thickness (LCT). Optic discs of 63 open angle glaucoma patients or glaucoma suspects were scanned with enhanced depth imaging spectral domain optical coherence tomography (SD-OCT). The B-scan images were constructed three-dimensionally using maximum intensity projection (MIP). The whole mip volume was then cut into thin slabs of two scan-line distance width (approximately 64 μm) at three 3 locations: mid-horizontal, and superior and inferior mid-peripheral regions of the optic nerve head. The LCT was measured in the thin-slab MIP images (LCT-MIP) and the three B-scans corresponding to each thin-slab MIP image (LCT-Bscan) at the three regions in each eye. The interobserver and intraobserver reproducibility of measuring the LCT-MIP and LCT-Bscan were evaluated by calculating the intraclass correlation coefficient (ICC), coefficient of variation (CV), and coefficient of repeatability (CR). The agreement between the LCT-MIP and the LCT-Bscan was assessed by Bland-Altman analysis. The thin-slab MIP images provided better image contrast with more distinct borders of the lamina cribrosa compared to the B-scan images. Both intraobserver and interobserver ICCs were higher for LCT-MIP than for LCT-Bscan in all areas. The 95% limit of agreement of measurement differences between LCT-Bscan and LCT-MIP ranged from -29.43 to 32.55 μm. The thin-slab MIP images provided a higher reproducibility in measuring the LCT using SD-OCT than the B-scan images. With thin-slab MIP images, the detection of the laminar borders was more straightforward. This technique should facilitate the evaluation of the lamina cribrosa.

Preoperative assessment of perigastric vascular anatomy by multidetector computed tomography angiogram for laparoscopy-assisted gastrectomy

We aimed at investigating the efficacy of multidetector computed tomography (MDCT) angiogram reconstructed using the maximum intensity projection (MIP) technique for the assessment of perigastric vascular anatomy before laparoscopy-assisted gastrectomy (LAG) for gastric cancer. Seventy-one patients who underwent LAG were enrolled in the study. Contrast-enhanced scans of the portal venous phase were performed by a MDCT scanner. The CT images were reconstructed using thin-slab MIP. The anatomic variations in the inflow and the location of the left gastric vein (LGV) were detected. The patterns of perigastric arterial origins were divided according to Michels' classification. The intraoperative blood loss on LAG was compared before and after MDCT angiography was introduced in the study. The LGV flowed into the portal vein in 31 patients; the splenic vein, 25 patients; and the junction of these two veins, 15 patients. The LGV passed to the dorsal and ventral sides of the common hepatic artery in 30 and 13 patients and to the dorsal and ventral sides of the splenic artery in 8 and 20 patients, respectively. Michels' type II was found in one patient; type V, in three patients; and type VI, in two patients. The LGV location detected by MDCT was confirmed during surgery in all cases. Intraoperative blood loss after introduction of the MDCT angiography was significantly less than that before its introduction (p = 0.0032). An MDCT angiogram reconstructed using the MIP technique is effective for assessing the perigastric vascular anatomy before LAG for gastric cancer.

Diagnosis of Vertebral Artery Ostial Stenosis on Contrast-Enhanced MR Angiography: Usefulness of a Thin-Slab MIP Technique

It is a well-known clinical fact that contrast-enhanced magnetic resonance angiography exaggerates vertebral arterial ostial stenosis and sometimes shows pseudostenosis. Considering the clinical significance of a lesion in the posterior circulation ischemia, the importance of an accurate imaging diagnosis of ostial stenosis should not be underestimated. We were able to differentiate pseudo stenosis of the ostium from true stenosis using thin-slab maximum-intensity-projection(MIP) images which are thought to be helpful for minimizing standard full thickness MIP images.

Effect of slab thickness on the CT detection of pulmonary nodules: Use of sliding thin-slab maximum intensity projection and volume rendering

Effect of slab thickness on the CT detection of pulmonary nodules: Use of sliding thin-slab maximum intensity projection and volume rendering

Effect of Slab Thickness on the CT Detection of Pulmonary Nodules: Use of Sliding Thin-Slab Maximum Intensity Projection and Volume Rendering

The objective of this study was to evaluate the detection rates of pulmonary nodules on CT as a function of slab thickness using sliding thin-slab maximum intensity projection (MIP) and volume rendering (VR). Eighty-eight oncology patients (33 women, 55 men; mean age, 59 years; age range, 18-81 years) who routinely underwent chest CT examinations were prospectively included. Two radiologists independently evaluated each CT examination for the presence of pulmonary nodules using MIP and VR, with each image reconstructed using three different slab thicknesses (5, 8, 11 mm). The standard of reference was the maximum number of detected nodules, which were classified by localization and size, judged to be true-positives by a consensus panel. Interreader agreement was assessed by kappa value on a nodule-by-nodule basis. Sensitivities for both reconstruction techniques and for the three slab thicknesses were calculated using the proportion procedure for survey data with the patient as the primary sample unit and were compared using the Wilcoxon's signed rank test with Bonferroni correction for both readers separately. One thousand fifty-eight true-positive nodules were detected. Interreader agreement was fair to moderate. Sensitivity for pulmonary nodules was superior for 8-mm MIP (reader 1, 84%; reader 2, 81%) and was significantly better than the sensitivities of all other tested techniques for both readers (p < 0.001 each) independent of nodule localization and size (except for one reader's analysis of 8-mm MIP versus 11-mm MIP for nodules > 8 mm). A higher sensitivity was achieved using MIP than VR. MIP with a slab thickness of 8 mm is superior in the detection of pulmonary nodules to all other tested techniques.

Efficacy of Computer-Aided Detection System and Thin-Slab Maximum Intensity Projection Technique in the Detection of Pulmonary Nodules in Patients With Resected Metastases

To evaluate the efficacy of the computer-aided detection (CAD) system and thin-slab maximum intensity projection (MIP) technique in the detection of pulmonary nodules at multidetector computed tomography (CT) in patients who underwent metastatectomy. This retrospective study was approved by the institutional review board and patients' informed consent was waived. Forty-nine consecutive patients who underwent pulmonary metastatectomy were enrolled. Four chest radiologists analyzed preoperative 1-mm section CT images and recorded the locus of each nodule candidate. Afterward, they reevaluated the images once using CAD software and once with thin-slab MIP given the results of 1-mm section CT alone. The reference standard for nodule presence was established by a consensus panel and pathologic records for malignant nodules. A total of 514 nodules were identified by a consensus panel. Of 212 nodules surgically removed, 121 nodules were malignant. The sensitivity of each observer in detecting malignant nodules with thin-section CT scans alone was 91%, 88%, 87%, and 86% for observers A- to D, respectively. With CAD, sensitivity increased significantly to 95%, 95%, 94%, and 95% (P< 0.05 for observer B-D), and using MIP increased to 94%, 96%, 91%, and 92% (P < 0.05 for observer B-D), respectively. There were no significant differences in sensitivity between CAD and MIP for the detection of malignant nodules. The average number of false-positive findings per patient was 0.8 with thin-section CT alone, 1.1 with CAD, and 1.4 with MIP. In candidates for metastatectomy, reading with the aid of either CAD or MIP significantly improved the detection of malignant nodules compared with using thin-section CT alone.