Axial Maximum Intensity Projection Research Articles

Image quality of whole-body diffusion MR images comparing deep-learning accelerated and conventional sequences.

To compare the image quality of deep learning accelerated whole-body (WB) with conventional diffusion sequences. Fifty consecutive patients with bone marrow cancer underwent WB-MRI. Two experts compared axial b900 s/mm2 and the corresponding maximum intensity projections (MIP) of deep resolve boost (DRB) accelerated diffusion-weighted imaging (DWI) sequences (time of acquisition: 6:42 min) against conventional sequences (time of acquisition: 14 min). Readers assessed paired images for noise, artefacts, signal fat suppression, and lesion conspicuity using Likert scales, also expressing their overall subjective preference. Signal-to-noise and contrast-to-noise ratios (SNR and CNR) and the apparent diffusion coefficient (ADC) values of normal tissues and cancer lesions were statistically compared. Overall, radiologists preferred either axial DRB b900 and/or corresponding MIP images in almost 80% of the patients, particularly in patients with a high body-mass index (BMI > 25 kg/m2). In qualitative assessments, axial DRB images were preferred (preferred/strongly preferred) in 56-100% of cases, whereas DRB MIP images were favoured in 52-96% of cases. DRB-SNR/CNR was higher in all normal tissues (p < 0.05). For cancer lesions, the DRB-SNR was higher (p < 0.001), but the CNR was not different. DRB-ADC values were significantly higher for the brain and psoas muscles, but not for cancer lesions (mean difference: + 53 µm2/s). Inter-class correlation coefficient analysis showed good to excellent agreement (95% CI 0.75-0.93). DRB sequences produce higher-quality axial DWI, resulting in improved MIPs and significantly reduced acquisition times. However, differences in the ADC values of normal tissues need to be considered. Deep learning accelerated diffusion sequences produce high-quality axial images and MIP at reduced acquisition times. This advancement could enable the increased adoption of Whole Body-MRI for the evaluation of patients with bone marrow cancer. Deep learning reconstruction enables a more than 50% reduction in acquisition time for WB diffusion sequences. DRB images were preferred by radiologistsin almost 80% of cases due to fewer artefacts, improved background signal suppression, higher signal-to-noise ratio, and increased lesion conspicuity in patients with higher body mass index. Cancer lesion diffusivity from DRB images was not different from conventional sequences.

A Fast Automatic Reconstruction Method for Panoramic Images Based on Cone Beam Computed Tomography

Panoramic images have been widely used in the diagnosis of dental diseases. In the process of panoramic image reconstruction, the position of the dental arch curve usually affects the quality of display content, especially the completion level of the panoramic image. In addition, the metal implants in the patient’s mouth often lead the contrast of the panoramic image to decrease. This paper describes a method to automatically synthesize panoramic images from dental cone beam computed tomography (CBCT) data. The proposed method has two essential features: the first feature is that the method can detect the dental arch curve through axial maximum intensity projection images over different ranges, and the second feature is that our method is able to adjust the intensity distribution of the implant in critical areas, to reduce the impact of the implant on the contrast of the panoramic image. The proposed method was tested on 50 CBCT datasets; the panoramic images generated by this method were compared with images attained from three other commonly used approaches and then subjectively scored by three experienced dentists. In the comprehensive image contrast score, the method in this paper has the highest score of 11.16 ± 2.64 points. The results show that the panoramic images generated by this method have better image contrast.

Diagnostic value of three-dimensional cube fluid attenuated inversion recovery imaging and its axial MIP reconstruction in multiple sclerosis

BackgroundMagnetic resonance imaging is regarded as one of the most important markers for multiple sclerosis. It can detect lesions in order to establish dissemination in time and space, which would aid in the diagnosis. Two-dimensional FLAIR is a standard sequence in MS routine imaging because it suppresses cerebrospinal fluid signal, increasing contrast between lesions and CSF and improving white matter lesion detection. Newer 3D FLAIR sequences are expected to offer even more benefits, such as improved MS lesions detection and higher resolution due to thinner slice thickness. We aimed to compare the role of 3D Cube FLAIR imaging (versus standard 2D FLAIR) in the assessment of white matter lesions in MS patients, as well as to test the convenience of using maximum intensity projection (MIP) on 3D FLAIR images for faster and easier evaluation.ResultsThis study included 160 MS patients. A 1.5 T routine brain MRI scan was performed, which included a 2D FLAIR sequence, followed by a 3D-FLAIR sequence. All images were analyzed after 3D-FLAIR images were reformatted into axial MIP images. Lesions were counted in each sequence and classified into supra-tentorial (periventricular, deep white matter, and juxta-cortical), and infra-tentorial lesions, with the relative comparison of lesions numbers on 3D-FLAIR and MIP versus 2D-FLAIR expressed as a percentage increase or decrease. 3D FLAIR can significantly improve MS lesion detection in all areas of the brain when compared with 2D FLAIR results. At 2 mm reformatting, there is no difference in MS lesion detection between sagittal 3D FLAIR and axial MIP reconstruction, implying that the MIP algorithm can be used to simplify lesion detection by reducing the number of images while maintaining the same level of reliability.Conclusion3D FLAIR sequences should be added to conventional 2D FLAIR sequences in the MRI protocol when MS is suspected.

An artificial intelligence system using maximum intensity projection MR images facilitates classification of non-mass enhancement breast lesions.

To build an artificial intelligence (AI) system to classify benign and malignant non-mass enhancement (NME) lesions using maximum intensity projection (MIP) of early post-contrast subtracted breast MR images. This retrospective study collected 965 pure NME lesions (539 benign and 426 malignant) confirmed by histopathology or follow-up in 903 women. The 754 NME lesions acquired by one MR scanner were randomly split into the training set, validation set, and test set A (482/121/151 lesions). The 211 NME lesions acquired by another MR scanner were used as test set B. The AI system was developed using ResNet-50 with the axial and sagittal MIP images. One senior and one junior radiologist reviewed the MIP images of each case independently and rated its Breast Imaging Reporting and Data System category. The performance of the AI system and the radiologists was evaluated using the area under the receiver operating characteristic curve (AUC). The AI system yielded AUCs of 0.859 and 0.816 in the test sets A and B, respectively. The AI system achieved comparable performance as the senior radiologist (p = 0.558, p = 0.041) and outperformed the junior radiologist (p < 0.001, p = 0.009) in both test sets A and B. After AI assistance, the AUC of the junior radiologist increased from 0.740 to 0.862 in test set A (p < 0.001) and from 0.732 to 0.843 in test set B (p < 0.001). Our MIP-based AI system yielded good applicability in classifying NME lesions in breast MRI and can assist the junior radiologist achieve better performance. • Our MIP-based AI system yielded good applicability in the dataset both from the same and a different MR scanner in predicting malignant NME lesions. • The AI system achieved comparable diagnostic performance with the senior radiologist and outperformed the junior radiologist. • This AI system can assist the junior radiologist achieve better performance in the classification of NME lesions in MRI.

Accelerated Pulmonary Ossification as a Sequela of SARS-CoV-2 Pneumonia

HomeRadiology: Cardiothoracic ImagingVol. 3, No. 2 PreviousNext Images in Cardiothoracic ImagingFree AccessPulmonary ImagingAccelerated Pulmonary Ossification as a Sequela of SARS-CoV-2 PneumoniaBeatriz García Moreno , Guadalupe Buitrago Weiland, María Luisa Sánchez Alegre, Jhon Edilberto Vanegas RodríguezBeatriz García Moreno , Guadalupe Buitrago Weiland, María Luisa Sánchez Alegre, Jhon Edilberto Vanegas RodríguezAuthor AffiliationsFrom the Department of Radiology, Hospital General Universitario Gregorio Marañón, Doctor Esquerdo 46, 28007 Madrid, Spain.Address correspondence to B.G.M. (e-mail: [email protected]).Beatriz García Moreno Guadalupe Buitrago WeilandMaría Luisa Sánchez AlegreJhon Edilberto Vanegas RodríguezPublished Online:Apr 1 2021https://doi.org/10.1148/ryct.2021200598MoreSectionsPDF ToolsImage ViewerAdd to favoritesCiteTrack Citations ShareShare onFacebookTwitterLinked In This case illustrates extensive dendriform lung ossification manifesting after SARS-CoV-2 pneumonia. Organizing pneumonia is an established CT finding in subacute SARS-CoV-2 infection (1,2), usually manifesting as bilateral consolidations (80%–95% of the cases) in a predominantly peripheral or peribronchial distribution, sometimes sparing the subpleural regions (3). Histologic analysis reveals plugs of fibroblastic tissue filling bronchioles and airspaces (3,4), which usually disappear after steroid treatment. However, fibromyxoid tissue may progress to fibrosis, a condition recently described as “cicatricial organizing pneumonia (4–6).” Some of these cases may evolve with pathologic osseous metaplasia, seen on imaging as nodular and branching calcifications, described as dendriform pulmonary ossification (5). This finding is usually seen in patients with underlying lung fibrosis, most commonly in usual interstitial pneumonia, and it is considered as a marker of chronicity and severity of lung fibrosis (7).Differential diagnoses include dystrophic calcifications, metastatic calcifications, and pulmonary alveolar microlithiasis. Dystrophic calcifications occur in diseased lung, in the settings of granulomatous infections, sarcoidosis, occupational lung diseases, and metabolic diseases (eg, as amyloidosis). Metastatic calcifications occur in normal lung due to hypercalcemia secondary to end-stage kidney disease. The differential diagnosis also includes nodular ossification seen in patients with chronic venous lung congestion (8). Normal renal function, phosphate calcium homeostasis, and the absence of any relevant past medical history or concomitant diseases excluded other causes of lung calcification/ossification in this case (Figs 1, 2).Figure 1: Images in a 49-year-old man who presented to the emergency department with SARS-CoV2 infection. A and B, Non–contrast-enhanced chest CT scans obtained 1 month after the onset of symptoms show multifocal peribronchovascular and peripheral consolidation, relatively sparing the subpleural region, consistent with organizing pneumonia. Follow-up chest CT was performed 6 months after steroid treatment. C, Axial and, D, coronal CT images show multiple micronodular calcifications within faint ground-glass opacities.Figure 1:Download as PowerPointOpen in Image Viewer Figure 2: Bone window images in same patient. Comparison between A, initial and, B, follow-up CT on axial maximum intensity projection images shows interval development of micronodular and branching calcifications, confirmed on C, coronal and, D, magnified axial views. Follow-up lung function testing revealed decreased diffusion capacity.Figure 2:Download as PowerPointOpen in Image Viewer Disclosures of Conflicts of Interest: B.G.M. disclosed no relevant relationships. G.B.W. disclosed no relevant relationships. M.L.S.A. disclosed no relevant relationships. J.E.V.R. disclosed no relevant relationships.Keywords: CT, Lung, Thorax Authors declared no funding for this work.

Reliability and accuracy of 3-mm and 2-mm maximum intensity projection CT angiography to detect intracranial large vessel occlusion in patients with acute anterior cerebral circulation stroke.

To evaluate the reliability and accuracy of thick maximum intensity projection (MIP) CTA images to detect large-vessel occlusion (LVO) in the anterior circulation in patients with acute stroke. A total of 140 acute stroke patients (41 with and 99 without LVO) were evaluated by two neuroradiologists for LVO using axial 3-mm and 2-mm MIPs. Interobserver agreement was substantial using 3-mm MIPs (ĸ = 0.67) and almost perfect using 2-mm MIPs (ĸ = 0.82). Using 3-mm MIPs, sensitivities were 80.5% and 68.3%, with specificities of 98.0% and 96.0%. Using 2-mm MIPs, sensitivities were 82.9% and 73.2%, with specificities of 98.0% and 99.0%. Sensitivity and specificity of 3 mm and 2 mm MIPs were not statistically significantly different (P ≥ 0.375). The majority of LVOs in the distal intracranial carotid artery, and/or M1-segment were correctly identified: 96.0% (observer 1, 3-mm MIPs), 88.0% (observer 2, 3-mm MIPs), 96.0% (observer 1, 2-mm MIPs), and 96.0% (observer 2, 2 mm MIPs). Using 3-mm MIP images, observers 1 and 2 missed 7/15 (46.7%) and 9/15 (60.0%) of isolated M2-segment occlusions, respectively. Using 2-mm MIP images, observers 1 and 2 missed 5/15 (33.3%) and 6/15 (40.0%) of isolated M2-segment occlusions, respectively. Thick (2-3 mm) axial MIPs are not useful to detect proximal LVO in the anterior circulation.

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.

The susceptibility ring.

The susceptibility ring.

Automatic reconstruction method for high-contrast panoramic image from dental cone-beam CT data

Background and objectivePanoramic images reconstructed from dental cone beam CT (CBCT) data have been effectively used in dental clinics for disease diagnosis. Panoramic images generally have low contrast because excessive non-interest tissues participate in the reconstruction, which may affect the diagnosis. In this study, we developed a fully automatic reconstruction method to improve the global and detail contrast of panoramic images. MethodsThe proposed method consists of dental arch thickness detection, image synthesis, and image enhancement. First, the dental arch thickness is detected from an axial maximum intensity projection (MIP) image generated from the axial slices containing the teeth to reduce non-interest tissues in panoramic image reconstruction. Then, a new synthesis algorithm is proposed at image synthesis stage to reduce the effect of non-interest tissues on image contrast. Finally, an image enhancement algorithm is applied to the synthesized image to improve the detail contrast of the final panoramic image. ResultsA total of 129 real clinical dental CBCT data sets were used to test the proposed method. The panoramic images generated by three methods were subjectively scored by three experienced dentists who were blinded to the generated method. The evaluation of image contrast included the maxillary, mandible, teeth, and particular region (root canal, crown reconstruction, implants, and metal brackets). The overall image contrast score revealed that the proposed method scored the highest of 11.03 ± 2.46, followed by the ray sum and x-ray methods with corresponding scores of 6.4 ± 1.65 and 5.35 ± 1.56. The results of expert subjective scoring indicated that the image contrast of the panoramic image generated by the proposed method is higher than those of existing methods. ConclusionsThe proposed method provides a quick, effective and robust solution to improve the global and detail contrast of the panoramic image generated from dental CBCT data.

Parallel imaging in time-of-flight magnetic resonance angiography using deep multistream convolutional neural networks.

To develop and evaluate a method of parallel imaging time-of-flight (TOF) MRA using deep multistream convolutional neural networks (CNNs). A deep parallel imaging network ("DPI-net") was developed to reconstruct 3D multichannel MRA from undersampled data. It comprises 2 deep-learning networks: a network of multistream CNNs for extracting feature maps of multichannel images and a network of reconstruction CNNs for reconstructing images from the multistream network output feature maps. The images were evaluated using normalized root mean square error (NRMSE), peak signal-to-noise ratio (PSNR), and structural similarity (SSIM) values, and the visibility of blood vessels was assessed by measuring the vessel sharpness of middle and posterior cerebral arteries on axial maximum intensity projection (MIP) images. Vessel sharpness was compared using paired t tests, between DPI-net, 2 conventional parallel imaging methods (SAKE and ESPIRiT), and a deep-learning method (U-net). DPI-net showed superior performance in reconstructing vessel signals in both axial slices and MIP images for all reduction factors. This was supported by the quantitative metrics, with DPI-net showing the lowest NRMSE, the highest PSNR and SSIM (except R = 3.8 on sagittal MIP images, and R = 5.7 on axial slices and sagittal MIP images), and significantly higher vessel sharpness values than the other methods. DPI-net was effective in reconstructing 3D TOF MRA from highly undersampled multichannel MR data, achieving superior performance, both quantitatively and qualitatively, over conventional parallel imaging and other deep-learning methods.

Abstract TP56: Comparison of Collateral Status in Acute Ischemic Stroke: Simulated 2-phase CTA versus Simulated 3-phase CTA

Purpose: We hypothesized that two-phase (the arterial phase and the phase between the peak and late venous phases) CTA may work comparably with 3-phase CTA, and sought to compare a simulated 3-phase CTA with a simulated 2-phase CTA for assessment of collaterals. Methods: We enrolled 155 patients (76 male; median, 72 years) who underwent 9.6-cm, 70-kVp perfusion CT (PCT) for 60 seconds within 8 hours after symptom onset and had occlusion in the ICA (ICA with/without M1; n=63) or M1 segment (with/without M2 segment; n=92). PCT data were reconstructed with a section width of 1 mm, and were used to create the simulated 3-phase CTA (3-CTA; peak arterial, peak venous, and late venous phase; 3 seconds each) with an increment of 4.5 seconds. Another 3-second CTA immediately after peak venous phase was additionally generated, which consisted of the second CTA of the simulated 2-phase CTA (2-CTA) with the peak arterial CTA. Each CTA was reconstructed into 25-mm axial maximum intensity projections, and was assessed by 2 independent reviewers at a separate session. For the 2-CTA, good collaterals were determined when the ipsilateral side showed both similar vascular filling and enhancement (ASPECT&gt;7) compared to the contralateral brain on the peak arterial CTA. For the 3-CTA, we followed the published criteria to determine good/poor collaterals. Results: Interobserver agreements were excellent (k=0.931 for 3-CTA; k=0.929 for 2-CTA). Consensus review determined good and poor collaterals in 97 and 58 patients, respectively, on 3-CTA. All 97 patients with good collaterals on 3-CTA showed good collaterals on 2-CTA; 2 out of 58 patients with poor collaterals on 3-CTA were determined to have good collaterals on 2-CTA, showing no significant difference (P=0.5, McNemar test). Conclusion: Compared to the simulated 3-phase CTA, the simulated 2-phase CTA has comparable diagnostic performance for determining the status of collateral circulation.

Utility of MDCT MIP Postprocessing Reconstruction Images in Children With Hereditary Hemorrhagic Telangiectasia.

The aim of the study was to evaluate whether maximum intensity projection (MIP) images improve the detection and the delineation of the anatomic makeup of pulmonary nodules and/or arteriovenous malformations (pAVMs) in children with hereditary hemorrhagic telangiectasia (HHT). Two radiologists (D.M., E.I.C.) performed a blinded review of chest multidetector computed tomography scans in 39 children (age, 0-18 years) with proven HHT. Multiplanar 2.5 mm slices were blindly compared with multiplanar MIP for the presence of nodules and/or overt pAVMs and for the ability to identify vessels associated with the pAVMs. Parameters that were assessed included number of definitive nodules, number of definitive pAVMs, and the ability to detect the feeding artery or draining vein in both conventional and MIP images. Our study showed similar detection rates between axial scans and MIP images for the detection of nodules (axial R1: 75 vs 62, P = 0.05; MIPS: 78 vs 86, P = 0.05) and in the determination of definite pAVMS (axials: 21 vs 29, P = 0.0007; MIPS: 27 vs 35, P = 0.01). Statistically significant differences were obtained in the ability to identify the feeding artery and draining vein between standard 2.5 mm slices and MIP images (axials: 13 vs 13, P = 0.0008; MIPS: 27 vs 23, P = 0.01). No other data parameters achieved statistically significance. Maximum intensity projection images in children with HHT can help identify the presence and the anatomy of pAVMs for future embolization.

Abstract P3-01-02: Clinical, anatomical and histological characteristics of breast lesions visualized by photoacoustic mammography; first clinical study in CK project

Abstract Background: Photoacoustic mammography (PAM) is an optical imaging technique potentially capable of imaging breast vasculature as well as measuring hemoglobin oxygen saturation(SO2) in focal breast lesions. We presented the initial observation on first 20 cases using the first generation PAM (PAM-01) prototype made by Canon Inc.(Tokyo, Japan) (spatial resolution:2mm) in SABCS 2013. Here we report the clinico-pathological characteristics of all cases recruited in the first clinical study in CK project (Kyoto University/Canon joint research project) between Aug 2010 and March 2012. Methods: 57 patients were recruited in IRB approved study at Kyoto University Hospital, Japan. Forty-two breast harboring lesions and when possible contralateral breasts were evaluated by PAM-01. Axial maximum intensity projection (MIP)s were obtained and signals from consecutive MIPs confirmed to be associated with the tumor location in MRI by an expert breast radiologist were considered to be the region of interest (ROI).The same depth was used for ROI in the normal breast as control. Histological sections from the widest area of the lesions were evaluated post-excisional by immunohistochemistry using anti-CD31 as endothelial marker and anti-carbonic anhydrase IX (CA IX) as hypoxia marker. Histological slides were scanned and divided into 1680 squares (0.84x0.84 mm2)(Hamamatsu Inc. Japan) for image analysis. Total vascular perimeter (TVP)-in mm- was calculated for all the histological section by using Image Pro-Plus 7.0 software (Media Cybernetics, USA). Tumor area was measured in mm2. TVP index was calculated as TVP/area. Results: Photoacoustic signal was detected in 30 lesions out of 42 at the depth of 26.8 ± 12.8 mm from which 80% were located superior to nipple. CA IX positive cases in comparison with CA IX negative cases significantly showed higher TVP index (p-value =0.028 Mann-Whitney Test ) suggesting more angiogenic profile of hypoxic tumors. However, lesions without any detectable signal were reported to have only a bigger mass size histologically (26.6 vs. 14.8 mm, p-value 0.28, Mann-Whitney Test) regardless of their TVP index or CA IX expression level. Moreover,SO2 was calculated 70.9% for signals located inside tumors and 85.5% for signals associated with subcutaneous vessels in the same breast (p-value &amp;lt;0.0001 Wilcoxon Test) compatible with the SO2 data from normal counterpart at tumor depth in the other breast (81.9%) (p-value 0.0001 Wilcoxon Test). Tumors bigger than 2 cm also tended to have lower SO2 (65.6%) compared with tumors smaller than 2 cm (70.1%) in accordance with higher TVP index in bigger tumors (p-value &amp;lt;0.001 Student T-test). Conclusion: This is the largest clinical study of PAM till today and the correlation between histological profile of hypoxia and tumor microvasculature with PAM signal visibility as well as tissue SO2 seems promising. However, the improvement of techniques and resolution is necessary to develop a more clinically applicable non-invasive functional breast imaging modality for analyzing breast tumor vasculature and hypoxia. Some of these improvements have taken place for the second generation PAM (PAM-02) which is now under a clinical evaluation study. Citation Format: Elham Fakhrejahani, Masae Torii, Yasufumi Asao, Iku Yamaga, Toshiyuki Kitai, Masako Kataoka, Shotaro Kanao, Masahiro Takada, Tsuyoshi Shiina, Masakazu Toi. Clinical, anatomical and histological characteristics of breast lesions visualized by photoacoustic mammography; first clinical study in CK project [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P3-01-02.

Bilateral pulmonary artery aneurysm in Behcet's disease

, et al., Bilateral pulmo .1016/j.injr.2015.02.005 Investigatory reports were haemoglobin 11.5 g/dl, Erythrocyte Sediment Ratio (ESR) 87 mm/h, C reactive protein (CRP) 20.79 mg/L and serum creatinine 0.41 mg/dl. A diagnosis of Behcet's disease (BD) was made and he was treated with prednisolone (10mg/day) and azathioprine (50mg/day). There was initial clinical improvement but subsequently he developed recurrent haemoptysiswhile hewas still on azathioprine and prednisolone. CT Pulmonary angiographywas done. Axial and coronal oblique MIP (Maximum Intensity Projections) images showed aneurysmal dilatation of the descending

Multidetector CT detection of peritoneal metastases: evaluation of sensitivity between standard 2.5mm axial imaging and maximum-intensity-projection (MIP) reconstructions.

Our purpose was to evaluate the sensitivity of multidetector CT for the detection of peritoneal metastases between standard 2.5mm axial imaging and maximum-intensity-projection (MIP) reconstructions. The Institutional Review Board approved this retrospective study and waived the need to obtain patient consent. We retrospectively identified 36 patients with pancreatic adenocarcinoma and peritoneal metastatic disease who underwent a pancreatic protocol CT examination of the abdomen and pelvis between January 2012 and January 2014. Three independent radiologists reviewed a randomized combination of standard axial (2.5mm reconstructed thickness, 2.5mm interval) and axial MIP reconstructions (6, 3mm interval) over two sessions. Each reader recorded metastasis location in PACS. Subsequent consensus review by two radiologists determined the final number and size of metastases. The reviewers found 328 peritoneal implants in 36 patients. After accounting for the size, location, and number of lesions as well as multiple readers, a generalized estimating equations model showed that the statistical combination of MIP with standard technique significantly increased the odds of correctly identifying a lesion (OR 2.16; 95% CI 1.86-2.51; p value<0.0001) compared to standard technique alone. MIP reconstruction as a standalone technique was less sensitive compared to standard technique alone (OR 0.81; 95% CI 0.65-0.99; p value=0.0468). When compared to standard axial imaging, evaluation via MIP reconstructions resulted in the identification of an additional 50 (15%), 45 (14%), and 55 (17%) lesions by Readers 1-3, respectively. The axial 6mm MIP series is complimentary in the CT evaluation of peritoneal metastases. MIP reconstruction evaluation identified a significant number of additional lesions, but is not adequate as a standalone technique for peritoneal cavity assessment.

Conditions and Mechanism for the Appearance of Interlobar Fissures as 5-Line Signs in Axial Maximum Intensity Projection Images

To assess the conditions and mechanism for the 5-line sign of normal interlobar fissures revealed on axial maximum intensity projection (MIP). Fifty subjects (32 males and 18 females aged 16 to 76 years) whose conditions were diagnosed as normal on computed tomography (CT) of the chest were presented. Images for the fissures with a slice thickness of 1.25 mm, a space thickness of 1.25 mm, and an MIP slab thickness of 6.25 mm were reconstructed. A 5-line shadow of normal interlobar fissures was shown on axial MIP imaging using a slab thickness of 6.25 mm. On axial MIP imaging, 93% of interlobar fissure parts were manifested as clear or barely clear. On axial MIP imaging using a slab thickness of 6.25 mm, normal interlobar fissures were displayed as 5-line signs, which, similar to the beaded small lung vessels shown on MIP imaging, might be a partial volume-averaging phenomenon.

Imaging features and follow-up of large extrahepatic portal vein aneurysm

A 67-year-old man presented at our hospital for routine abdominal imaging studies before planned surgery for lung cancer. He had no obvious abdominal complaints. He had a history of chronic pancreatitis. Physical examination revealed no abnormal findings. Routine blood tests, including liverassociated enzymes, did not show any remarkable findings. We performed ultrasound (US) imaging, which demonstrated a 5.44.3-cm, round-shaped anechoic lesion at the hepatic hilum. Color Doppler US imaging showed bidirectional color due to circular flow within this lesion (A, arrows). Abdominal contrast-enhanced multidetector computed tomography (CT) and CT angiography with three-dimensional reconstructions using maximum-intensity projection (B, white arrow) and volume-rendering technique (Cover) confirmed the diagnosis of a saccular aneurysm at the truncus of the portal vein close to its bifurcation. Pancreatic calcifications were also present (B, black arrow). Complementary magnetic resonance imaging angiography showed the aneurysm with no abnormality of the liver and spleen. Axial maximum-intensity projection reformatted sections demonstrated that right and left branches of portal vein were normal (C, arrows). Thus, our patient was considered to have an acquired extrahepatic portal vein aneurysm (PVA) due to his history and imaging features of pancreatitis. Two years after the diagnosis, the aneurysm had not grown in size. Because our patient had no serious complaints or liver disease, surgical procedures had not been used.

Detection of pulmonary nodules at paediatric CT: maximum intensity projections and axial source images are complementary

Maximum intensity projection (MIP) images might be useful in helping to differentiate small pulmonary nodules from adjacent vessels on thoracic multidetector CT (MDCT). The aim was to evaluate the benefits of axial MIP images over axial source images for the paediatric chest in an interobserver variability study. We included 46 children with extra-pulmonary solid organ malignancy who had undergone thoracic MDCT. Three radiologists independently read 2-mm axial and 10-mm MIP image datasets, recording the number of nodules, size and location, overall time taken and confidence. There were 83 nodules (249 total reads among three readers) in 46 children (mean age 10.4 ± 4.98 years, range 0.3-15.9 years; 24 boys). Consensus read was used as the reference standard. Overall, three readers recorded significantly more nodules on MIP images (228 vs. 174; P < 0.05), improving sensitivity from 67% to 77.5% (P < 0.05) but with lower positive predictive value (96% vs. 85%, P < 0.005). MIP images took significantly less time to read (71.6 ± 43.7 s vs. 92.9 ± 48.7 s; P < 0.005) but did not improve confidence levels. Using 10-mm axial MIP images for nodule detection in the paediatric chest enhances diagnostic performance, improving sensitivity and reducing reading time when compared with conventional axial thin-slice images. Axial MIP and axial source images are complementary in thoracic nodule detection.

Carotid stenosis assessment with multi-detector CT angiography: comparison between manual and automatic segmentation methods

Luminal stenosis is used for selecting the optimal management strategy for patients with carotid artery disease. The aim of this study is to evaluate the reproducibility of carotid stenosis quantification using manual and automated segmentation methods using submillimeter through-plane resolution Multi-Detector CT angiography (MDCTA). 35 patients having carotid artery disease with >30 % luminal stenosis as identified by carotid duplex imaging underwent contrast enhanced MDCTA. Two experienced CT readers quantified carotid stenosis from axial source images, reconstructed maximum intensity projection (MIP) and 3D-carotid geometry which was automatically segmented by an open-source toolkit (Vascular Modelling Toolkit, VMTK) using NASCET criteria. Good agreement among the measurement using axial images, MIP and automatic segmentation was observed. Automatic segmentation methods show better inter-observer agreement between the readers (intra-class correlation coefficient (ICC): 0.99 for diameter stenosis measurement) than manual measurement of axial (ICC = 0.82) and MIP (ICC = 0.86) images. Carotid stenosis quantification using an automatic segmentation method has higher reproducibility compared with manual methods.

Automated multiscale vessel analysis for the quantification of MR angiography of peripheral arteriogenesis

To automatically analyze the time course of collateralization in a rat hindlimb ischemia model based on signal intensity distribution (SID). Time-of-flight magnetic resonance angiograms (TOF-MRA) were acquired in eight rats at 2, 7, and 21 days after unilateral femoral artery ligation. Analysis was performed on maximum intensity projections filtered with multiscale vessel enhancement filter. Differences in SID between ligated limb and a reference region were monitored over time and compared to manual collateral artery identification. The differences in SID correlated well with the number of collateral arteries found with manual quantification. The time courses of ultrasmall (diameter ≪0.5 mm) and small (diameter ≈0.5 mm) collateral artery development could be differentiated, revealing that maturation of the collaterals and enlargement of their feeding arteries occurred mainly after the first week postligation. SID analysis performed on axial maximum intensity projections is easy to implement, fast, and objective and provides more insight in the time course of arteriogenesis than manual identification.