Maximum Intensity Projection Reconstruction Research Articles

Multiplane Reconstruction Modifies The Diagnostic Performance Of CT Angiography In Carotid Webs

IntroductionCarotid Web (CaW) represents an overlooked stroke etiology and has been associated with high recurrency rates and to be amenable to stenting. We evaluated the diagnostic performance of different computed tomography angiography (CTA) projections in CaW. MethodsConsecutive patients <65 years-old with symptomatic CaW (n=31), carotid atherosclerosis (n=27), or normal carotids (n=49) diagnosed with a thin-cut CTA were included. Deidentified CTAs were independently reviewed by three readers, who recorded the diagnosis and level of certainty after evaluating the axial plane alone, after adding sagittal/coronal maximum intensity projection (MIP), then after oblique MPR reformats. ResultsThere were 93 total CaW, 81 atherosclerosis, and 147 normal carotid reads. With CTA axial projection alone, less CaW cases (44.1%) were appropriately diagnosed as compared to atherosclerosis (87.7%; p<0.001) and normal carotid (83%; p<0.001) cases. Sagittal/coronal MIPS increased the rate of accurate CaW diagnosis (44.1% to 76.3%; p<0.001). Inter-rater agreement in CaW detection increased from k= 0.46 (0.35-0.57) using axial to k= 0.80 (0.69-0.91) with sagittal/coronal planes. Axial alone had lower sensitivity (44% vs. 76%) but similar specificity (95% vs. 96%) in CaW detection compared to axial+ sagittal/coronal MIPS. The accuracy in detecting atherosclerosis or normal carotids did not increase after adding sagittal/coronal MIPS and oblique MPRs. The certainty level for CaW diagnosis was lower when compared to atherosclerosis and normal carotids using axial alone (3.0 [3.0-4.0] vs. 4.0 [3.0-5.0]; p<0.001 and 4.0 [3.0- 5.0]; p<0.001) as well as after adding sagittal/coronal MIPS (4.0 [3.0-5.0] vs. 5.0[4.0-5.0]; p=0.01 and 4.0 [4.0-5.0]; p<0.001). ConclusionCTA axial plane alone was insufficient for CaW detection. CTA sagittal/coronal MIP reconstructions as well as oblique MPR reformats enhanced the accuracy and confidence related to CaW diagnosis.

The Atlas of the Inferior Mesenteric Artery and Vein under Maximum-Intensity Projection and Three-Dimensional Reconstruction View

(1) Background: Understanding vascular patterns is crucial for minimizing bleeding and operating time in colorectal surgeries. This study aimed to develop an anatomical atlas of the inferior mesenteric artery (IMA) and vein (IMV). (2) Methods: A total of 521 patients with left-sided colorectal cancer were included. IMA and IMV patterns were identified using maximum-intensity projection (MIP) and three-dimensional (3D) reconstruction techniques. The accuracy of these techniques was assessed by comparing them with surgical videos. We compared the amount of bleeding and operating time for IMA ligation across different IMA types. (3) Results: Most patients (45.7%) were classified as type I IMA, followed by type II (20.7%), type III (22.6%), and type IV (3.5%). Newly identified type V and type VI patterns were found in 6.5% and 1% of patients, respectively. Of the IMVs, 49.9% drained into the superior mesenteric vein (SMV), 38.4% drained into the splenic vein (SPV), 9.4% drained into the SMV–SPV junction, and only 2.3% drained into the first jejunal vein (J1V). Above the root of the left colic artery (LCA), 13.1% of IMVs had no branches, 50.1% had one, 30.1% had two, and 6.7% had three or more branches. Two patients had two main IMV branches, and ten had IMVs at the edge of the mesocolon with small branches. At the IMA root, 37.2% of LCAs overlapped with the IMV, with 34.0% being lateral, 16.9% distal, 8.7% medial, and both the marginal type of IMV and the persistent descending mesocolon (PDM) type represented 1.4%. MIP had an accuracy of 98.43%, and 3D reconstruction had an accuracy of 100%. Blood loss and operating time were significantly higher in the complex group compared to the simple group for IMA ligation (p &lt; 0.001). (4) Conclusions: A comprehensive anatomical atlas of the IMA and IMV was provided. Complex IMA patterns were associated with increased bleeding and operating time.

Leveraging open dataset and transfer learning for accurate recognition of chronic pulmonary embolism from CT angiogram maximum intensity projection images

BackgroundEarly diagnosis of the potentially fatal but curable chronic pulmonary embolism (CPE) is challenging. We have developed and investigated a novel convolutional neural network (CNN) model to recognise CPE from CT pulmonary angiograms (CTPA) based on the general vascular morphology in two-dimensional (2D) maximum intensity projection images.MethodsA CNN model was trained on a curated subset of a public pulmonary embolism CT dataset (RSPECT) with 755 CTPA studies, including patient-level labels of CPE, acute pulmonary embolism (APE), or no pulmonary embolism. CPE patients with right-to-left-ventricular ratio (RV/LV) < 1 and APE patients with RV/LV ≥ 1 were excluded from the training. Additional CNN model selection and testing were done on local data with 78 patients without the RV/LV-based exclusion. We calculated area under the receiver operating characteristic curves (AUC) and balanced accuracies to evaluate the CNN performance.ResultsWe achieved a very high CPE versus no-CPE classification AUC 0.94 and balanced accuracy 0.89 on the local dataset using an ensemble model and considering CPE to be present in either one or both lungs.ConclusionsWe propose a novel CNN model with excellent predictive accuracy to differentiate chronic pulmonary embolism with RV/LV ≥ 1 from acute pulmonary embolism and non-embolic cases from 2D maximum intensity projection reconstructions of CTPA.Relevance statementA DL CNN model identifies chronic pulmonary embolism from CTA with an excellent predictive accuracy.Key points• Automatic recognition of CPE from computed tomography pulmonary angiography was developed.• Deep learning was applied on two-dimensional maximum intensity projection images.• A large public dataset was used for training the deep learning model.• The proposed model showed an excellent predictive accuracy.Graphical

A Study on Ureteric Abnormalities in Single Contrast Bolus CT Urography at A Tertiary Care Centre

Introduction: CT urography is an imaging technique in which the i.v contrast is injected and phases of CT scan are taken to study the entire urinary system. It has essentially replaced intravenous urography (IVU) in most imaging practices. CT Urography has evolved as an ideal imaging tool for comprehensive imaging assessment of patients with flank pain, malignancies, hematuria, trauma, renal calculi, suspected congenital malformations and in various clinical settings. Other CT advantages include the use of multiplanar reconstruction (MPR), curved planar reformatted images, maximum intensity projection (MIP) and three-dimensional (3D) reconstruction which gives valuable information to the clinician about the extent of the lesions and helps in management.&#x0D; Aim: To study various types of ureteric abnormalities in CT Urography in various clinical presentation.&#x0D; Materials and methods: This is a tertiary hospital based observational Descriptive Cross sectional study conducted on 360 patients referred for CT Urography with Clinical Signs &amp; Symptoms of urinary tract abnormalities, having ureteric imaging abnormalities. Siemens somatum High Definition 128 slice CT scanner was used for single bolus CT urography.&#x0D; Results: Males were more as compared to females with age group 31 to 50 years (44.4%). Abdominal pain with urinary complaints was seen in maximum number of patients (203 cases- 56.4%). Urinary complaints in known abdomino-pelvic malignancies was seen in 18% cases. 285 patients had obstructive urography findings like hydronephrosis or hydroureter, and 75 cases had non obstructive findings like ureteral filling defects due to calculi, clots, etc or abnormal ureteric course or only congenital abnormality. Most hydroureter cases were secondary to obstructive calculus followed by obstruction by external malignant mass.&#x0D; Conclusion: This study outlines the most common ureteric abnormalities in patients referred for CT urography which were mostly obstructive findings most cases were secondary to obstructive calculus followed by obstruction by external malignant mass. The non obstructive findings like ureteral filling defects were due to calculi, clots, etc or abnormal ureteric course or only congenital abnormalities. Delayed phase of CT urography can also be applied in Contrast CT study of abdomen &amp; Pelvic scans on case to case basis to study ureteric involvements &amp; pathologies.

Imaging findings of hepatocellular carcinoma with portal vein tumor thrombosis secondary to hepatic portal vein collateral circulation: a cross-sectional study.

Hepatic portal vein collateral circulation plays an important role in maintaining the perfusion of hepatic portal vein. However, at present, there is little research on collateral circulation of hepatic portal vein. Our study aims to analysis the imaging types and clinical value of hepatocellular carcinoma (HCC) with portal vein tumor thrombus (PVTT) invading and completely blocking different branches of portal vein, secondary to hepatic portal vein collateral circulation. This study retrospectively analyzed Hepatocellular carcinoma (HCC) with PVTT diagnosed with enhanced CT examination of the upper abdomen in our hospital from May 2020 to October 2021.The inclusion criteria for patients were the following: (I) ultimately diagnosed with HCC, (II) accompanied by complete obstruction of the main portal vein or left/right branches, and (III) with collateral circulation of the hepatic portal vein established. All images were postprocessed by multiplanar reconstruction (MPR), maximum intensity projection (MIP), and other reconstruction techniques to obtain images of the abnormal portal vein system and the collateral vessels running toward the hepatic portal veins. Three physicians jointly judged the imaging anatomical classification of each collateral vessel. The qualitative variables were compared by chi-squared test. A total of 125 hepatic portal vein collateral vessels were observed in MPR and MIP reconstruction images of 71 patients with portal vein cancer thrombosis with established hepatic portal vein collateral circulation. Common hepatic collateral branches in patients with PVTT mainly include the biliary collateral branch, gastric collateral branch, mesenteric collateral branch, accessory portal vein system and the splenic branch. The incidence rate was respectively 77.5%, 36.6%, 32.4%, 28.2%, 1.41%. The correct understanding of the imaging anatomical classification of the collateral vessels of the hepatic portal vein can provide clinicians with more information for diagnosis and treatment planning.

Prevalence of hepatic vascular anomalies in consecutive contrast-enhanced computed tomography images — a retrospective observational study

BackgroundLiver is a complex, highly vascular organ, where anatomical variations are the norm. This study aimed to analyze all the three hepatic vascular anatomical variations in a single study which would help us understand the prevalence of hepatic vascular (arterial, portal, venous) anomalies in the population catered to by our institution.MethodsA retrospective analysis of 545 contrast-enhanced CT scans was done from November 2019 from the institute PACS after satisfying the inclusion and exclusion criteria. The raw imaging data were processed in PACS software — Centricity™ Universal Viewer and Syngo.via Vb20 platform, for axial, coronal, and axial-oblique multiplanar reformation, maximum intensity projection (MIP), and volume rendering (VR) images. Data were analyzed in the three vascular phases to determine the anatomical variations. Analysis was done by two surgical residents in the division of HPB surgery, which was verified by a certified radiologist.ResultsThere were no major differences in the prevalence rates of the vascular anomalies across gender and domicile distributions. The prevalence of normal hepatic artery and variant hepatic artery in our study was 69% and 31%, respectively. Accessory left hepatic artery (10%) was the most common hepatic artery variant in our study. Single RHV was seen in 77.4%, and other RHV variants like two RHV with common trunk, two RHV with independent drainage, and three RHV with common trunk contribute 22.6% of our study population. Accessory inferior RHV was seen in 19.8% of the study population. Normal portal vein anatomy was found in 81.1% in our study, and the most common variant in our study population was trifurcation of portal vein (16.1%).ConclusionThis was the largest study until date from South India, studying all three hepatic vascular anatomical variations in a single study. Variations in the anatomy of hepatic arteries, portal veins, and hepatic veins are common. A good knowledge of the same is necessary especially for a hepatobiliary surgeon or for an interventional radiologist, to plan and avoid complications during a procedure. Preoperative contrast-enhanced CT scan and whenever necessary a VR or a MIP reconstruction will precisely help in identifying these variations.

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.

Anatomical variations of the branches from left colic artery and middle colic artery at splenic flexure.

Variations of the vasculature at splenic flexure by left colic artery (LCA) and middle colic artery (MCA) remain ambiguous. This study aim to investigate the anatomical variations of the branches from LCAand MCA at splenic flexure area. Using ultra-thin CT images (0.5-mm thickness), we traced LCA and MCA till their merging site with paracolic marginal arteries through maximum intensity projection (MIP) reconstruction and computed tomography angiography (3D-CTA). A total of 229 cases were retrospectively enrolled. LCA ascending branch approached upwards till the distal third of the transverse colon in 37.6%, reached the splenic flexure in 37.6%, and reachedthe lower descending colon in 23.1%, and absent in 1.7% of the cases. Areas supplied by MCA left branch and aMCA were 33.2%, 44.5% and 22.3% in the proximal, middle and distal third of transverse colon of the cases, respectively. The accessory MCA separately originated from the superior mesenteric artery was found in 17.9% of the cases. Mutual correlation was found that, when the LCA ascending branch supplied the distal transverse colon, MCA left branch tended to feed the proximal transverse colon; when the LCA ascending branch supplied the lower part of descending colon, MCA left branch was more likely to feed the distal third of transverse colon. Vasculature at splenic flexure by LCA and MCA varied at specific pattern. This study could add more anatomical details for vessel management in surgeries for left-sided colon cancer.

Feasibility of Single-Shot Whole Thoracic Time-Resolved MR Angiography to Evaluate Patients with Multiple Pulmonary Arteriovenous Malformations.

ObjectiveTo evaluate the feasibility of single-shot whole thoracic time-resolved MR angiography (TR-MRA) to identify the feeding arteries of pulmonary arteriovenous malformations (PAVMs) and reperfusion of the lesion after embolization in patients with multiple PAVMs.Materials and MethodsNine patients (8 females and 1 male; age range, 23–65 years) with a total of 62 PAVMs who underwent percutaneous embolization for multiple PAVMs and were subsequently followed up using TR-MRA and CT obtained within 6 months from each other were retrospectively reviewed. All imaging analyses were performed by two independent readers blinded to clinical information. The visibility of the feeding arteries on maximum intensity projection (MIP) reconstruction and multiplanar reconstruction (MPR) TR-MRA images was evaluated by comparing them to CT as a reference. The accuracy of TR-MRA for diagnosing reperfusion of the PAVM after embolization was assessed in a subgroup with angiographic confirmation. The reliability between the readers in interpreting the TR-MRA results was analyzed using kappa (κ) statistics.ResultsFeeding arteries were visible on the original MIP images of TR-MRA in 82.3% (51/62) and 85.5% (53/62) of readers 1 and 2, respectively. Using the MPR, the rates increased to 93.5% (58/62) and 95.2% (59/62), respectively (κ = 0.760 and 0.792, respectively). Factors for invisibility were the course of feeding arteries in the anteroposterior plane, proximity to large enhancing vessels, adjacency to the chest wall, pulsation of the heart, and small feeding arteries. Thirty-seven PAVMs in five patients had angiographic confirmation of reperfusion status after embolization (32 occlusions and 5 reperfusions). TR-MRA showed 100% (5/5) sensitivity and 100% (32/32, including three cases in which the feeding arteries were not visible on TR-MRA) specificity for both readers.ConclusionSingle-shot whole thoracic TR-MRA with MPR showed good visibility of the feeding arteries of PAVMs and high accuracy in diagnosing reperfusion after embolization. Single-shot whole thoracic TR-MRA may be a feasible method for the follow-up of patients with multiple PAVMs.

Pterygospinous and pterygoalar bars in children.

The formation of pterygoalar (Pa) and pterygospinous (Ps) bars are controversial whether they are secondary ossifications with aging or phylogenetic remnant. Therefore we aimed to evaluate the presence of Pa and Ps bars in children on routine cranial computed tomography images. We retrospectively analyzed the cranial computed tomography images of 500 children under the age of 18. Besides the 0.5mm axial images, maximum intensity projection and 3D reconstructions were also used. The existence of incomplete or complete Pa and Ps bars were investigated. Incomplete and complete Pa bar was detected in 4.6% and 2.2% of the cases, respectively. Incomplete Ps bar was seen in 13.6% of the cases and complete was in 6%. In total, per 1000 sides, 12 (2.4%) complete and 27 (5.4%) incomplete Pa bars were detected. In the same way, 35 (7%) complete and 88 (17.6%) incomplete Ps bars were seen. The smallest age ossification detected was 5months old. Additionally, the prevalence of Pa and Ps bars between the under and over 10years old age groups were statistically significant. Aging increased the prevalence. Considering our results, it seems that the ossification of Pa and Ps ligaments may not be solely related with aging.

Prevalence of Increased FDG PET/CT Axillary Lymph Node Uptake Beyond 6 Weeks after mRNA COVID-19 Vaccination.

Ipsilateral avid axillary lymph node uptake at FDG PET/CT persists in 29% (49 of 169) of patients between 7 to 10 weeks after the second dose of the mRNA-based BNT162b2 COVID-19 vaccination.

Diagnostic Performance of a Lower-dose Contrast-Enhanced 4D Dynamic MR Angiography of the Lower Extremities at 3 T Using Multisegmental Time-Resolved Maximum Intensity Projections.

For peripheral artery disease (PAD), MR angiography (MRA) is a well-established diagnostic modality providing morphologic and dynamic information comparable to digital subtraction angiography (DSA). However, relatively large amounts of contrast agents are necessary to achieve this. To evaluate the diagnostic accuracy of time-resolved 4D MR-angiography with interleaved stochastic trajectories (TWIST-MRA) by using maximum intensity projections (MIPs) of dynamic images acquired with reduced doses of contrast agent. Retrospective. Forty adult PAD patients yielding 1088 artery segments. A 3.0 T, time-resolved 4D MR-angiography with TWIST-MRA and MIP of dynamic images. DSA was available in 14 patients (256 artery segments) and used as reference standard. Three-segmental MIP reconstructions of TWIST-images after administration of 3 mL of gadolinium-based contrast agent (Gadoteridol/Prohance®, 0.5 M) per anatomical level (pelvis, thighs, and lower legs) yielded 256 artery segments for correlation between MRA and DSA. Three independent observers rated image quality (scale: 1 [nondiagnostic] to 4 [excellent]) and the degree of venous overlay (scale: 0 [none] to 2 [significant]) for all segments. Diagnostic accuracy for the detection of >50% stenosis and artery occlusion was calculated for all observers. Binary classification test (sensitivity, specificity, positive/negative predictive values, diagnostic accuracy). Intraclass correlation coefficients (ICCs), logistic regression analysis with comparison of areas under the receiver-operating-characteristics (ROC) curves (AUCs) with the DeLong method. Bland-Altman-comparison. High diagnostic performance was achieved for the detection of >50% stenosis (sensitivity 92.9% [84.3-99.9% (95%-CI)] and specificity 98.5% [95.7-99.8% (95%-CI)]) and artery occlusion (sensitivity 93.1% [77.2-99.2% (95%-CI)] and specificity 99.1% [96.9-99.9% (95%-CI)]). Inter-reader agreement was excellent with ICC values ranging from 0.95 to 1.0 for >50% artery stenosis and occlusion. Image quality was good to excellent for both readers (3.41 ± 0.72, 3.33 ± 0.65, and 3.38 ± 0.61 [mean ± SD]) with good correlation between observer ratings (ICC 0.71-0.81). No significant venous overlay was observed (0.06 ± 0.24, 0.23 ± 0.43 and 0.11 ± 0.45 [mean ± SD]). MIPs of dynamic TWIST-MRA offer a promising diagnostic alternative necessitating only reduced amounts (50%) of gadolinium-based contrast agents for the entire runoff vasculature. 3 TECHNICAL EFFICACY: Stage 2.

NUTRACKER SYNDROME

In the nutcracker anatomy, the aortomesenteric angle is more acute, which leads to a compression of the left renal vein between the aorta and the superior mesenteric artery. As a result, there is an impended outflow of the left renal vein in the inferior vena cava. This is termed as nutcracker syndrome.&nbsp; Complex of clinical symptoms exists in the nutcracker syndrome (NS). Nutcracker phenomenon (NP) is the term used to describe an anatomic finding without any clinical symptoms. The aim of this case study was to show the use of a multiphase computed tomography as a diagnostic method of choice in dealing with cases of nutcracker anatomy in patients. We present four cases of patients who underwent computed tomography of the abdomen. Two of the cases were with anterior nutcracker syndrome, one case was with posterior nutcracker syndrome and one case with nutcracker phenomenon. Establishing of the exact diagnosis in these patients is difficult, because of the rarity and variety in symptoms. Existence of the clinical symptoms distinguishes whether the patient has NS or NP. Multiphase CT scan of the abdomen with additional reconstructions in maximum intensity projection (MIP), volume rendering (VR) and multiplanar reconstruction (MPR) as an imaging method is the method of choice in the diagnosis of NS and NP. Keywords: nutcracker syndrome, nutcracker phenomenon, computed tomography, anatomic variations

ROLE OF COLOR DOPPLER ULTRASONOGRAPHY VERSUS TRIPHASIC CT WITH PORTOGRAPHY IN PORTAL VEIN THROMBOSIS

Back ground: Although portal vein thrombosis is a rare event among general population, its prevalence in cirrhotic patients about 28 % (1). Generally liver cirrhosis is a widespread disease, the differentiation between bland and malignant thrombus is very essential as neoplastic portal vein thrombosis gravely affects the prognosis and the subsequent treatment options (1). Doppler ultrasonography usually the first noninvasive modality used to diagnose portal vein thrombosis, using color and spectral data analysis. Triphasic CT with portography is very helpful to differentiate bland from malignant thrombus and enable characterization of malignant portal vein thrombosis using maximum intensity projection (MIP) reconstruction allow better analysis of the thrombus (2).Aim of the work: To show the role of color Doppler ultrasonography (US) and Triphasic CT in diagnosis of portal vein thrombosis (PVT) and differentiation between bland and tumoral thrombus.Patient and Methods: This study included 32 cases presented with portal vein thrombosis clinically and radiologically.Results: Of the 32 subjects,21 had malignant PVT and 11 patients had benign PVT. Direct invasion of portal vein from adjacent focal lesion had the highest sensitivity 95.2 % was achieved, with a specificity of 100 %. The Positive predictive value (PPV) was 100 %, while the negative predictive value (NPV) was 91.7 %. Early arterial enhancement and rapid washout of contrast showed 76.2 % sensitivity and 100 % specificity, PPV 100 % and NPV 68.8 %. Pulsatile flow within the thrombus depicted 38.1 % sensitivity, 100 % specificity with PPV 100 % and NPV 45.8 %.Conclusion: Triphasic CT and color Doppler US have to be considered a useful tools in evaluating portal vein thrombosis provides helpful information for the detection and characterization of malignant and benign portal vein thrombi.

Role of CT Imaging With Three-Dimensional Maximum Intensity Projection Reconstruction in the Evaluation of Portal Vein Variants at a Tertiary Care Hospital

Introduction: Portal vein (PV) is the principal blood vessel transporting blood from the alimentary tract and spleen to the liver. The aim of this study is to determine the prevalence of PV anatomical variations in our population using multidetector CT with maximum intensity projection (MIP) technique at a tertiary care hospital.Methods: This cross-sectional study was prospectively conducted from November 2018 to June 2019 in the Department of Radiology at a tertiary care hospital in Karachi. After informed consent, all the patients with no known hepatic pathology undergoing routine abdomen CT were included in this study. Patients with previous hepatic resection surgeries, undiagnosed large hepatic tumors/metastasis, and those with PV thrombosis were excluded.Results: A total of 500 patients (256 males and 244 females) were included in the study; the mean age of female patients was relatively higher as compared to the male patients (53.80 ± 18.44 vs. 44.15 ± 19.94 years; p = 0.000). Standard PV anatomy (type 1) was found in 438 patients (87.6%). Trifurcation (type 2) occurred in 18 patients (3.6%). Right posterior portal vein as the first branch of main PV (type 3) was found in 22 patients (4.4%). A separate branch of the right portal vein (RPV) to segment VII (type 4) and separate branch of the RPV to segment VI (type 5) were found in 6 (1.2%) and 16 (3.2%) patients, respectively.Conclusion: Our study displayed a relatively higher frequency of standard PV anatomy (type 1) compared to previous studies. We highlight the role of MIP in the analysis of hepatic venous anatomy with its utility demonstrating improved detection of variations.

Thin Slices and Maximum Intensity Projection Reconstructions Increase Sensitivity to Hyperdense Middle Cerebral Artery Sign in Acute Ischemic Stroke

Introduction: Cranial nonenhanced CT (NECT) imaging in hyperacute ischemic stroke is rarely used for assessing arterial obstruction of middle cerebral artery by identifying hyperdense artery sign (HAS). Considering, however, its growing importance due to its impact on the decision-making process of thrombolysis with or without mechanical thrombectomy improved sensitivity to HAS is necessary, particularly in the group of less experienced clinicians being frequently the first one assessing the presence of HAS on NECT. Objective: The present study aimed to investigate the effect of different NECT image reconstructions on the correct detection of hyperdense middle cerebral artery sign in a cohort of observers with lower experience level on NECT. Particularly, MIP image reconstructions were expected to be useful for less experienced observers due to both strengthening of the hyperdensity of HAS and streamlining to less image slices. Methods: Twenty-five of 100 patients’ NECT image data presented with HAS. Sixteen observers with lower practice level on NECT (10 radiologists and 6 neurologists) evaluated independently the 3 image reconstructions of each data set with thin slice 1.5 mm, thick slab 5 mm, and 6-mm maximum intensity projection (MIP) and rated the presence of HAS in middle cerebral artery. A GEE model with random observer effect was used to examine the influence of the 3 image reconstructions on sensitivity to HAS. A linear mixed effects regression model was used to investigate the ranking of detectability of HAS. Interrater reliability was determined by Fleiss’ kappa coefficient (κ). Results: Recognition of HAS and sensitivity to HAS significantly differed between the 3 image reconstructions (p = 0.0106). MIP and thin slice reconstructions yielded each on average the highest sensitivities with 73% compared to thick slab reconstruction with 45% sensitivity. The interobserver reliability was fair (κ, 0.3–0.4). Detectability of HAS was significantly easier and better visible ranked on MIP and thin slice reconstructions compared to thick slab (p < 0.05). Conclusion: MIP and thin slice reconstructions increased the sensitivity to HAS (73%), whereas thick slab reconstructions seemed to be less appropriate (45%).

Magnetic resonance cholangiopancreatography with compressed sensing at 1.5 T: clinical application for the evaluation of branch duct IPMN of the pancreas

ObjectivesTo evaluate magnetic resonance cholangiopancreatography (MRCP) with compressed sensing (CS) for the assessment of branch duct intraductal papillary mucinous neoplasm (BD-IPMN) of the pancreas. For this purpose, conventional navigator-triggered (NT) sampling perfection with application-optimized contrast using different flip angle evolutions (SPACE) MRCP was compared with various CS-SPACE-MRCP sequences in a clinical setting.MethodsA total of 41 patients (14 male, 27 female, mean age 68 years) underwent 1.5-T MRCP for the evaluation of BD-IPMN. The MRCP protocol consisted of the following sequences: conventional NT-SPACE-MRCP, CS-SPACE-MRCP with long (BHL, 17 s) and short single breath-hold (BHS, 8 s), and NT-CS-SPACE-MRCP. Two board-certified radiologists evaluated image quality, duct sharpness, duct visualization, lesion conspicuity, confidence, and communication with the main pancreatic duct in consensus using a 5-point scale (1–5), with higher scores indicating better quality/delineation/confidence. Maximum intensity projection reconstructions and originally acquired data were used for evaluation. Wilcoxon signed-rank test was used to compare the intra-individual difference between sequences.ResultsBHS-CS-SPACE-MRCP had the highest scores for image quality (3.85 ± 0.79), duct sharpness (3.81 ± 1.05), and duct visualization (3.81 ± 1.01). There was a significant difference compared with NT-CS-SPACE-MRCP (p < 0.05) but no significant difference to the standard NT-SPACE-MRCP (p > 0.05). Concerning diagnostic quality, BHS-CS-SPACE-MRCP had the highest scores in lesion conspicuity (3.95 ± 0.92), confidence (4.12 ± 1.08), and communication (3.8 ± 1.06), significantly higher compared with NT-SPACE-MRCP, BHL-SPACE-MRCP, and NT-CS-SPACE-MRCP (p = <0.05).ConclusionsMRCP with CS 3D SPACE for the evaluation of BD-IPMN at 1.5 T provides the best results using a short breath-hold sequence. This approach is feasible and an excellent alternative to standard NT 3D MRCP sequences.Key Points• 1.5-T MRCP with compressed sensing for the evaluation of branch duct IPMN is a feasible method.• Short breath-hold sequences provide the best results for this purpose.

THE ANALYSIS RELATED VARIATION SLICE THICKNESS TO IMAGE INFORMATION RECONSTRUCTION MAXIMUM INTENSITY PROJECTION (MIP) MSCT ANGIOGRAFI ABDOMINAL IN THE HOSPITAL TELOGOREJO SEMARANG

The Research of this study was to determine the relationship of slice thickness to Maximum Intensity Projection (MIP) reconstructive image information and determine the exact slice thickness to the MIP processing of MSCT examination of Abdominal Angiography. Type of research is quantitative with an experimental approach, using a sample of 6 patients. Each patient performed a MIP reconstruction of the abdominal artery that is truncus coeliacs artery, gastric artery, hepatic artery, splenic artery, superior mesenteric artery, inferior mesenteric artery, renal artery, and communis iliac artery with variations in slice thickness of 5, 10, 15, 20 and 25 mm. Correlation test results produce a P-value= 0.001 smaller than α= 0.05 so that Ho is rejected and Ha is accepted, which means there is a relationship between slice thickness with image information on the MIP processing of abdominal arteries. Correlation coefficient value obtained is 0.593 so that the relationship obtained is moderate. The negative relationship is that the smaller the slice thickness, the diagnostic information on the abdominal artery is clearer, the greater the slice thickness, the diagnostic information generated is increasingly unclear. MIP reconstruction of the abdominal artery can produce clear image information on 5 mm and 10 mm.

Diagnostic Accuracy of Maximum Intensity Projection in Diagnosis of Malignant Pulmonary Nodules.

IntroductionPulmonary nodules are frequently encountered during chest imaging, and its evaluation is usually done by chest radiograph and computed tomography (CT) scan of chest. High resolution of multidetector CT (MDCT) has improved the nodule detection. Post processing techniques such as maximum intensity projection (MIP) can further improve the sensitivity of MDCT for nodule detection. Failure to diagnose malignancy in pulmonary nodules can delay the treatment. Therefore, the aim of this study was to determine the diagnostic accuracy of MIP in the diagnosis of malignant pulmonary nodules taking histopathology findings as gold standard.Materials and methodsA retrospective cross-sectional study was conducted at Dow Institute of Radiology, Dow University of Health Sciences, from 1 December 2018 till 30 June 2019. Both male and female patients aged 18 years and above who underwent CT scan of chest with suspicion of pulmonary nodules were included. Patients already diagnosed with malignant pulmonary nodules and presenting for follow-up were excluded. Contrast-enhanced CT chest was performed on a multi-slice scanner. MIP reconstruction and evaluation was performed on the workstation. Sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of MIP were calculated taking histopathology findings as gold standard.ResultsA total of 202 patients were included in this study. The mean age of the patients was 55.87 ± 13.08 years. A total of 103 patients (51.0%) were males and 99 patients (49.0%) were females. There were 131 (64.9%) nodules with smooth margins and 71 (35.1%) nodules with irregular margins. The mean size of nodule was 3.1 ± 0.7 cm. Sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of MIP in diagnosing malignant pulmonary nodules were found to be 85.82%, 82.35%, 90.55%, 74.67%, and 84.65%, respectively, taking histopathology findings as gold standard. The nodules >3 cm in size had a higher sensitivity for diagnosing malignant pulmonary nodules. Smooth margin nodule had high sensitivity, specificity, and diagnostic accuracy for diagnosing malignant pulmonary nodules.ConclusionMIP images have high sensitivity, specificity, and diagnostic accuracy in the diagnosis of malignant pulmonary nodules. The utilization of MIP images can aid in the detection of malignant pulmonary nodules and help in formulating early treatment strategies for the patients. Other post processing techniques such as volume rendering and computer-aided detection can help in further improving patient care.

Ossification of the pterygoalar and pterygospinous ligaments: a computed tomography analysis of infratemporal fossa anatomical variants relevant to percutaneous trigeminal rhizotomy.

Ossification of pterygoalar and pterygospinous ligaments traversing the superior aspect of the infratemporal fossa results in formation of osseous bars that can obstruct percutaneous needle access to the trigeminal ganglion through the foramen ovale (FO), interfere with lateral mandibular nerve block, and impede transzygomatic surgical approaches. Presence of these ligaments has been studied on dry skulls, but description of their radiological anatomy is scarce, in particular on cross-sectional imaging. The aim of this study was to describe visualization of pterygoalar and pterygospinous bars on computed tomography (CT) and to review their prevalence and clinical significance. The authors retrospectively reviewed 200 helical sinonasal CT scans by analyzing 0.75- to 1.0-mm axial images, maximum intensity projection (MIP) reconstructions, and volume rendered (VR) images, including views along the anticipated axis of the needle in percutaneous Hartel and submandibular approaches to the FO. Ossified pterygoalar and pterygospinous ligaments were readily identifiable on CT scans. An ossified pterygoalar ligament was demonstrated in 10 patients, including 1 individual with bilateral complete ossification (0.5%), 4 patients with unilateral complete ossification (2.0%), and 5 with incomplete unilateral ossification (2.5%). Nearly all patients with pterygoalar bars were male (90%, p < 0.01). An ossified pterygospinous ligament was seen in 35 patients, including 2 individuals with bilateral complete (1.0%), 8 with unilateral complete (4%), 8 with bilateral incomplete (4.0%), 12 with bilateral incomplete (6.0%) ossification, and 5 (2.5%) with mixed ossification (complete on one side and incomplete on the contralateral side). All pterygoalar bars interfered with a hypothetical needle access to the FO using the Hartel approach but not the submandibular approach. In contrast, 54% of complete and 24% of incomplete pterygospinous bars impeded the submandibular approach to the FO, without affecting the Hartel approach. This study provides the first detailed description of cross-sectional radiological and applied surgical anatomy of pterygoalar and pterygospinous bars. Our data are clinically useful during skull base imaging to predict potential obstacles to percutaneous cannulation of the FO and assist in the choice of approach, as these two variants differentially impede the Hartel and submandibular access routes. Our results can also be useful in planning surgical approaches to the skull base through the infratemporal fossa.