Minimum Intensity Projection Images Research Articles

Exploration of the correlation between superficial cerebral veins identified using susceptibility-weighted imaging findings and cognitive differences between sexes based on deep learning: a preliminary study.

This study aimed to investigate the association of superficial cerebral veins (SCVs) with sex-related cognitive differences and the possible hemodynamic mechanisms underlying these associations. This investigation was a prospective case-control study. A total of 344 healthy volunteers were recruited. In all, 200 volunteers were included to establish the deep learning model, and 144 volunteers were used for the research, including 72 males (50%) and 72 females (50%). No significant differences in age (P=0.358) or education (P=0.779) were observed between the sexes. Cognitive functioning was evaluated using neuropsychological tests, including the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment-Basic (MOCA-B). Susceptibility-weighted imaging scans were acquired with a 3.0 T magnetic resonance imaging system using a 32-channel high-resolution phased array coil. Minimum intensity projection images were obtained by reconstructing susceptibility-weighted imaging data. A deep learning model was trained on the minimum intensity projection images to quantify the diameter, tortuosity index, length, and the number of SCVs in the bilateral cerebral hemispheres. Finally, the association between cognitive differences between males and females and the properties of the SCVs was analyzed. The MMSE and MOCA-B scores of males were significantly higher than those of females (P<0.05). Males had more SCVs in the bilateral cerebral hemispheres than did females (right hemisphere: P<0.01; left hemisphere: P<0.05). The number of SCVs in the right cerebral hemisphere was significantly and positively correlated with the MMSE and MOCA-B scores (correlation coefficients: 0.246 and 0.201, respectively; P<0.05). The number of SCVs in the left cerebral hemisphere was positively correlated with the MMSE scores (correlation coefficient: 0.196; P<0.05) and the MOCA-B scores. In this study, no significant correlations were observed between cognition and the diameter, length, or tortuosity index of the SCVs in the bilateral cerebral hemispheres. The cognitive function of males was better than that of females, and the different numbers of SCVs may be one of the explanations for this phenomenon of sex-based differences in cognition.

Ferumoxytol-enhanced magnetic resonance imaging with volume rendering: A new approach for the depiction of internal placental structure in vivo

IntroductionPlacental function is vitally important, but placental assessment is limited by current imaging methods in vivo. The goal of this study is to determine if ferumoxytol-enhanced MR studies might be used to depict placental structure during pregnancy. MethodsTen pregnant women were referred for MRI evaluation of abnormal placentation. The study group was composed five of these patients whose placentas were normal at pathology. MR studies consisted of pre-contrast SSFSE (single-shot fast spin-echo), SSFP (steady-state free procession), diffusion, and ferumoxytol-enhanced acquisitions. The post-contrast sequences were compared to pre-contrast SSFSE, SSFP, and diffusion acquisitions for features of correspondence. MR images were also compared to histopathology for anatomic landmarks including the three-ring pattern of the functional vascular exchange unit (the placentone) created by this central cavity surrounded by a ring of clustered villi, and an outer ring of dispersed villi corresponding to the maternal venous outflow channel. The measured sizes of these features on MR were compared to reported sizes. ResultsPost-ferumoxytol images showed enhancement of the maternal blood within the placenta, notably the intervillous space and the myometrial vessels. The unenhanced fetal vessels were most visible on the MinIP (minimum intensity projection) images; the enhanced maternal vessels were most visible on the MIP (maximum intensity projection) images. Composite MIP/MinIP images show the relation of maternal and fetal circulations. The signal intensities replicate the relative contributions from enhanced maternal blood and unenhanced chorionic villi. DiscussionFerumoxytol-enhanced MR imaging can depict the internal anatomy of the placenta in vivo of clarity and detail. This could represent a new diagnostic approach to placental disorders.

Panorama of multidetector-row computed tomography findings of carcinoma gall bladder - A retrospective observational study.

Carcinoma of the gall bladder (Ca GB) has marked ethnic and geographical variations with a broad spectrum of imaging findings on multidetector-row computed tomography (MDCT). We aim to study the spectrum of the imaging findings of Ca GB on MDCT in an Eastern Indian hospital as these imaging findings help in accurate diagnosis and staging of this lethal disease. The MDCT images of 100 biopsy-proven cases of adenocarcinoma of GB performed from January 1, 2017, to December 31, 2018, in our hospital were retrospectively reviewed by two experienced radiologists blinded to the diagnosis. The CT protocol was a plain scan followed by triple-phase contrast-enhanced CT. Reconstructed images in the form of maximum intensity projection, volume-rendered technology, and minimum intensity projection images were also assessed. Descriptive statistics were used for data analysis. Ca GB showed a female predominance (female:male -1.9:1). The mean age of presentation was 54.7 years (females) and 58 years (males). The morphological patterns were a mass replacing the GB (46%), focal or diffuse wall thickening (26%), and an intraluminal polypoidal mass (28%). Direct extension was to liver (76%), duodenum (32%), colon (19%), pancreas (9%), and abdominal wall (1%). Biliary dilatation (53%), vascular invasion (14%), omental involvement (23%), ascites (22%), N1 (40%), and retroperitoneal lymphadenopathy (33%) were common. Distant metastasis comprised of hepatic (42%), pulmonary (7%), Krukenberg's tumor (6%), and osseous (1%) lesions. The stages at diagnosis were I or II (3%), IIIA (4%), IIIB (16%), IVA (10%), and IVB (67%). Ca GB has a broad spectrum of findings on MDCT and it mostly presents at an advanced stage. MDCT with reconstructions is beneficial in the assessment of locoregional and distant spread and cancer staging which has a direct implication on patient management, survival, and mortality.

Utility of minimum intensity projection images based on three-dimensional CUBE T1 weighted imaging for evaluating middle cerebral artery stenosis.

This study investigated the diagnostic performance of MinIP images based on three-dimensional variable-flip-angle turbo spin echo T1 weighted imaging (3D CUBE T1WI) from high-resolution vessel wall magnetic resonance imaging for detecting middle cerebral artery (MCA) stenosis. A total of 63 consecutive patients were included in this study. MinIP images were reconstructed using 3D CUBE T1WI as the source images. The degree and length of MCA stenosis were measured on MinIP images and were compared with digital subtraction angiography (DSA) as the reference standard. The intra- and interobserver agreement for both the rate and length of MCA stenosis were excellent for the MinIP images. There was also excellent agreement in the degree of MCA stenosis calculated using MinIP images and DSA. MinIP images had a high sensitivity, specificity for diagnosing MCA stenosis. There was a good correlation between the two methods for measuring the rate and length of MCA stenosis. MinIP images based on 3D CUBE T1WI are highly consistent with DSA for evaluating the degree and length of MCA stenosis. MinIP images can be produced as a derivative from vessel wall imaging and implemented as an adjunct to vessel wall imaging without extra acquisition time.

Improved minimum intensity projection in holographic reconstruction via SNR-enhanced holography

In digital in-line particle holography (DIPH), minimum intensity projection (MIP) is a crucial step in the reconstruction procedure, the MIP image quality is significantly degraded by nonuniform-illumination, speckle noise and the artifacts from off-focal planes. Here, we report a method that improves the MIP image quality by fully exploiting the advantages of SNR-enhanced holography, along with a nouniform illumination correction procedure without requiring a-priori assumptions about particle structures. Experimental results for nonspherical particles show that the proposed method can correct nonuniform-illumination and mitigate the artifacts from off-focal planes, allowing one to extract the particle’s size, shape and transverse location from a 2D single image.

Applying the paralleling technique in intraoral periapical radiographs for Japanese patients by analyzing CT images.

The aim of this study was to investigate the size of the teeth and palatal heights to determine if it is possible to apply the paralleling technique in the upper molar region in Japanese patients. The medical computed tomography (CT) data of ten patients were analyzed. A minimum intensity projection image with 8-mm slice thickness was created for each second premolar, first molar, and second molar tooth. We traced the tooth, the alveolar bone, the plate bone surface, and the cheek skin surface on a tracing paper. Tooth length (TL), palatal height (PH), distance between a tip of the cheek and each tooth (D1), and distance between each tooth and the receptor (D2) were measured. The measurements were performed by two observers, and the measurements were repeated twice by each observer. Two potential situations were considered for application of the paralleling technique. We analyzed whether there was a possibility for application of the paralleling technique comparing the TL and the PH for each case by considering the magnification rate calculated from D1 and D2, the palatal mucosa thickness, and the safety margin within the resultant image. The data suggested that applying the paralleling technique was impossible in 95% of cases. In the cases where application of the paralleling technique was impossible, the incident angle of X-ray increased by 31.6°. We concluded that the paralleling technique could not be applied in Japanese patients due to insufficient space for the image receptor in the upper maxilla region.

Right-Angled Traction Bronchiectasis in Differentiating Idiopathic Pulmonary Fibrosis Without Honeycombing From Idiopathic Nonspecific Interstitial Pneumonia.

The aim of this study was to conduct a radiopathologic evaluation of right-angled traction bronchiectasis to differentiate idiopathic pulmonary fibrosis (IPF) without honeycombing from idiopathic nonspecific interstitial pneumonia (NSIP). The derivation cohort included 78 consecutive patients with idiopathic NSIP (n = 39) or IPF (n = 39) without honeycombing who underwent preoperative thin-section computed tomography scans at a single tertiary hospital. The validation cohort comprised 22 patients (14 IPF and 8 NSIP) from another institution. We assessed conventional computed tomography findings, right-angled traction bronchiectasis on minimum intensity projection (MinIP) images, and pathologic features associated with right-angled bronchiectasis. Right-angled traction bronchiectasis was defined as abrupt kinking of a single bronchus by over 90 degrees or an abrupt angle close to 180 degrees of branching bronchi in the background of fibrosis. In the validation cohort, we evaluated the proportion of correct IPF diagnoses and interobserver agreement of 4 radiologists before and after reviewing MinIP images. A probable usual interstitial pneumonia (UIP) pattern (odds ratio [OR], 6.948; 95% confidence interval [CI], 1.525-31.654; P = 0.012) and right-angled traction bronchiectasis (OR, 6.004; 95% CI, 1.980-18.209; P = 0.002) were independently associated with IPF. Patients with right-angled traction bronchiectasis were more likely to have extensive reticular opacity (OR, 1.149; 95% CI, 1.077-1.225; P < 0.001) and pathologically were more likely to have a broad extent of subpleural fibrosis (OR, 4.000; 95% CI, 1.457-10.987; P = 0.007) and relatively thick fibrosis (OR, 7.750; 95% CI, 2.504-23.991; P < 0.001). After reviewing MinIP images, the proportion of correct diagnoses increased from 40.9% to 54.5% to 50.0% to 77.3%. The mean kappa value for right-angled traction bronchiectasis was 0.489 ± 0.192. Right-angled traction bronchiectasis pathologically reflected a subpleural predominance of fibrosis and partly supported the radiologic differentiation of IPF without honeycombing from idiopathic NSIP.

Study on the Effect of 4D-CT Special Reconstruction Images for Evaluation of the Cardiac Structure Dose in Radiotherapy for Breast Cancer.

Objective: To study the dosimetric effect on special reconstruction images obtained from an electrocardiograph-gated four-dimensional computed tomography (ECG 4D-CT) series and compare it with the accumulation dose assessment of ECG 4D-CT.Methods: Fifteen patients underwent ECG 4D-CT scans to obtain a 4D-CT series. The 20 phase images of 0–95% were reconstructed at intervals of 5% of the cardiac cycle by the 4D-CT series. The 4D-CT series was specially reconstructed, and the maximum intensity projection (MIP), minimum intensity projection (MinIP), average intensity projection (AIP), and sum intensity projection (SIP) were obtained. The left ventricular muscle (LV) and the anterior descending branch of the left coronary artery (LAD) were delineated on all series. The intensity-modulated radiation therapy (IMRT) plan for left breast cancer was designed on the basis of the 0% phase, and the accumulative dose (Dose−acc) of 20 phases was obtained by deformation registration. The dose-volume indexes of the LV and LAD were compared based on different CT series.Results: The dose-volume indices of V5, V30, V40, Dmax, and Dmean of the LV on MIP images were 3.8, 2.0, 0.9, 3.8, and 1.7%, respectively (relative to the Dose−acc). There was no significant difference in V5 or Dmax between the MIP and Dose−acc (P > 0.05). The change rates of Dmax on the MinIP, SIP, and AIP images were 2.5, 3.1, and 1.5%, respectively (relative to the Dose−acc) (P < 0.05).Conclusion: In the dose-volume evaluation of the LV, V30, V40, and Dmean obtained by MIP were essentially the same as those obtained by the Dose−acc and can be used instead of the 4D-CT series to evaluate dose-volume indexes.

Comparison of the dose on specific 3DCT images and the accumulated dose for cardiac structures in esophageal tumors radiotherapy: whether specific 3DCT images can be used for dose assessment?

BackgroundCardiac activity could impact the accuracy of dose assessment for the heart, pericardium and left ventricular myocardium (LVM). The purpose of this study was to explore whether it is possible to perform dose assessment by contouring the cardiac structures on specific three-dimensional computed tomography (3DCT) images to reduce the impact of cardiac activity.MethodsElectrocardiograph-gated 4DCT (ECG-gated 4DCT) images of 22 patients in breath-hold were collected. MIM Maestro 6.8.2 (MIM) was used to reconstruct specific 3DCT images to obtain the Maximal intensity projection (MIP) image, Average intensity projection (AIP) image and Minimum intensity projection (Min-IP) image. The heart, pericardium and LVM were contoured in 20 phases of 4DCT images (0, 5%... 95%) and the MIP, AIP and Min-IP images. Then, a radiotherapy plan was designed at the 0% phase of the 4DCT images, and the dose was transplanted to all phases of 4DCT to acquire the dose on all phases, the accumulated dose of all phases was calculated using MIM. The dose on MIP, AIP and Min-IP images were also obtained by deformable registration of the dose. The mean dose (Dmean), V5, V10, V20, V30 and V40 for the heart, pericardium and LVM in MIP, AIP and Min-IP images were compared with the corresponding parameters after dose accumulation.ResultsThe mean values of the difference between the Dmean in the MIP image and the Dmean after accumulation for the heart, pericardium and LVM were all less than 1.50 Gy, and the dose difference for the pericardium and LVM was not statistically significant (p > 0.05). For dose-volume parameters, there was no statistically significant difference between V5, V10, and V20 of the heart and pericardium in MIP, AIP, and Min-IP images and those after accumulation (p > 0.05). For the LVM, only in the MIP image, the differences of V5, V10, V20, V30 and V40 were not significant compared to those after dose accumulation (p > 0.05).ConclusionsThere was a smallest difference for the dosimetry parameters of cardiac structures on MIP image compared to corresponding parameters after dose accumulation. Therefore, it is recommended to use the MIP image for the delineation and dose assessment of cardiac structures in clinical practice.

Extracting more for less: multi-echo MP2RAGE for simultaneous T1 -weighted imaging, T1 mapping, mapping, SWI, and QSM from a single acquisition.

To demonstrate simultaneous T1 -weighted imaging, T1 mapping, mapping, SWI, and QSM from a single multi-echo (ME) MP2RAGE acquisition. A single-echo (SE) MP2RAGE sequence at 7 tesla was extended to ME with 4 bipolar gradient echo readouts. T1 -weighted images and T1 maps calculated from individual echoes were combined using sum of squares and averaged, respectively. ME-combined SWI and associated minimum intensity projection images were generated with TE-adjusted homodyne filters. A QSM reconstruction pipeline was used, including a phase-offsets correction and coil combination method to properly combine the phase images from the 32 receiver channels. Measurements of susceptibility, , and T1 of brain tissue from ME-MP2RAGE were compared with those from standard ME-gradient echo and SE-MP2RAGE. The ME combined T1 -weighted, T1 map, SWI, and minimum intensity projection images showed increased SNRs compared to the SE results. The proposed coil combination method led to QSM results free of phase-singularity artifacts, which were present in the standard adaptive combination method. T1 -weighted, T1 , and susceptibility maps from ME-MP2RAGE were comparable to those obtained from SE-MP2RAGE and ME-gradient echo, whereas maps showed increased blurring and reduced SNR. T1 , , and susceptibility values of brain tissue from ME-MP2RAGE were consistent with those from SE-MP2RAGE and ME-gradient echo. High-resolution structural T1 weighted imaging, T1 mapping, mapping, SWI, and QSM can be extracted from a single 8.5-min ME-MP2RAGE acquisition using a customized reconstruction pipeline. This method can be applied to replace separate SE-MP2RAGE and ME-gradient echo acquisitions to significantly shorten total scan time.

Effect of Slab Thickness on the Detection of Pulmonary Nodules by Use of CT Maximum and Minimum Intensity Projection.

OBJECTIVE. The purpose of this study was to investigate the effect of slab thickness on the detection of pulmonary nodules by use of maximum-intensity-projection (MIP) and minimum-intensity-projection (MinIP) to process CT images. MATERIALS AND METHODS. Chest CT data of 221 patients with pulmonary nodules were retrospectively analyzed. Nodules were categorized into two groups according to density: solid nodules (SNs) and subsolid nodules (SSNs). Pulmonary nodules were independently evaluated by two radiologists using axial CT images with 1-mm and 5-mm section thickness and MIP and MinIP images. MIP images for SN detection and MinIP images for SSN detection were separately reconstructed with four (5, 10, 15, 20 mm) and three (3, 8, 15 mm) slab thicknesses. The numbers and locations of detected nodules were recorded, and interobserver agreement was assessed. For each reader, the differences in nodule detection rates were evaluated in different series of images. RESULTS. Among the different series of images, interobserver agreements for detecting nodules were all good to excellent (κ ≥ 0.687). For total SNs and SNs with a diameter < 5 mm, detection rates on 10-mm MIP images were significantly higher than in other series of images (reader 1, 84.5% and 83.8%; reader 2, 83.6% and 82.2%). For total SSNs and SSNs < 5 mm, detection rates on 3-mm MinIP images were significantly higher than those in other series of images, except for 1-mm (reader 1, 93.3% and 78.6%; reader 2, 95.0% and 81.0%). CONCLUSION. Ten-millimeter MIP images are extremely efficient for detecting SNs. Three-millimeter MinIP images are more useful for visualizing SSNs, the efficiency being comparable to that achieved by use of 1-mm axial images.

Micro-CT of tracheal stenosis in trisomy 21

A male infant with trisomy 21, born at 36 weeks' gestation, had care withdrawn at 2 months of age and was referred for postmortem investigations. The child had been ventilator...

Clinical Significance of Asymmetric Minimum Intensity Projection Images of Brain Magnetic Resonance Imaging in Children.

Background and PurposeThe susceptibility-weighted imaging form of brain MRI using minimum intensity projection (mIP) is useful for assessing traumatic brain injuries because it readily reveals deoxyhemoglobin or paramagnetic compounds. We investigated the efficacy of using this methodology in nontraumatic patients.MethodsWe retrospectively analyzed the asymmetric mIP findings in nontraumatic patients. Asymmetric mIP images were first verified visually and then using ImageJ software. We enrolled patients with a difference of >5% between hemispheres in ImageJ analysis. All patients underwent detailed history-taking and EEG, and asymmetric mIP findings were compared.ResultsThe visual analysis identified 54 pediatric patients (37 males and 17 females) with asymmetric mIP findings. Ten patients were excluded because they did not meet the ImageJ verification criteria. The 44 patients with asymmetry comprised 36 with epilepsy, 6 with headache, and 2 with cerebral infarction. Thirty-one of the 36 epileptic patients showed definite partial seizure activities in semiology, while the remaining patients did not demonstrate a history of partial seizure manifestations. The MRI findings were normal in all patients except for five with periventricular leukomalacia unrelated to seizure symptoms. There was agreement between mIP images and semiology in 29 (93.5%) of the 31 epileptic patients with focal signs, while the other 2 demonstrated discordance. Twenty (64.5%) of the 31 patients showed consistent EEG abnormalities.ConclusionsOur data suggest that asymmetric mIP findings are an excellent lateralizing indicator in pediatric patients with partial epilepsy.

Minimum-intensity projection images in high-resolution computed tomography lung: Technology update

Chest physicians need to be aware about MinIP images, as these are increasingly being used for the evaluation of a wide range of lung diseases in HRCT study of lungs. MinIP images highlight the areas with reduced CT attenuation in the lung parenchyma. This allows prompt and early diagnosis of cystic lung diseases or airway, vascular or parenchymal disorders, which manifest with hypoattenuation, mosaic attenuation or air trapping. MiniP images are therefore useful for accurate pre-operative planning and disease monitoring.

Multi-detector CT (MDCT) evaluation in interstitial lung disease (ILD): Comparison of MinIP and volumetric high resolution CT (HRCT) images

The aim of the studyIs to compare the role of minimum intensity projection (MinIP) images with that of volumetric high resolution computed tomography (HRCT) images in the diagnosis of interstitial lung diseases (ILD). Patients and methods180 patients (149 females and 31 males) were included in this prospective study that took place over a duration of two and half years. All patients underwent HRCT and MinIP images. The positive findings were compared recording which technique was better and if MinIP adds a value in reaching an accurate diagnosis. ResultsMinIP images showed better visualization of traction bronchiectasis, ground glass opacities and mosaic attenuation pattern, as well as, the cystic lung changes seen in LAM. While MinIP did not add a significant value in thick-walled cystic changes e.g.: honeycombing. ConclusionMinIP is one of the multiplanar techniques of HRCT that proved throughout our study to be an informative complementary tool increasing the observer confidence and agreement regarding some findings as compared with HRCT alone.

Enhanced susceptibility-weighted angiography (ESWAN) of cerebral arteries and veins at 1.5 Tesla.

Enhanced susceptibility-weighted angiography (ESWAN) is a three-dimensional (3D) multi-echo gradient-echo sequence which consists of both magnitude and phase images. This study aims to demonstrate the feasibility of ESWAN for the depiction of both cerebral arteries and veins at 1.5 T by comparing with time-of-flight (TOF) MR angiography (MRA) and MR venography (MRV). 13 healthy volunteers underwent both ESWAN and 3D-TOF-MRA examinations. Among them, nine volunteers underwent an additional two-dimensional-TOF-MRV examination. With regard to the ESWAN sequence, both maximum intensity projection (MIP) and minimum intensity projection (mIP) images were reconstructed and compared with MIP reconstructions of the TOF MRA and the TOF MRV. Concerning the depiction of the constituent segments of the Circle of Willis, as well as A1, A2, A3 (segments of the anterior cerebral artery), M1, M2 (segments of the middle cerebral artery), P1 and P2 (segments of the posterior cerebral artery), the value of the ESWAN MIP was comparable to that of the TOF MRA without regard to visualization of branches, vessel homogeneity and wall irregularities or slight stenosis. ESWAN-mIP visualized more deep cerebral veins than TOF MRV in this study. By use of either mIP reconstruction of a long echo data set or MIP reconstruction of a short echo data set, ESWAN allows simultaneous visualization of both cerebral veins and proximal segments of intracerebral arteries at 1.5 T. ESWAN acquires multiple images at different echo times corresponding to different T2* weightings, wherein a short echo TOF-MRA data set and a long echo susceptibility-weighted imaging-MRV data set are obtained simultaneously.

Susceptibility-weighted imaging is suitable for evaluating signal strength in different brain regions of a rabbit model of acute hemorrhagic anemia.

Susceptibility-weighted imaging is suitable for evaluating signal strength in different brain regions of a rabbit model of acute hemorrhagic anemia.

Comparison of Alternative Image Reformatting Techniques in Micro–Computed Tomography and Tooth Clearing for Detailed Canal Morphology

IntroductionMicro–computed tomography (MCT) shows detailed root canal morphology that is not seen with traditional tooth clearing. However, alternative image reformatting techniques in MCT involving 2-dimensional (2D) minimum intensity projection (MinIP) and 3-dimensional (3D) volume-rendering reconstruction have not been directly compared with clearing. The aim was to compare alternative image reformatting techniques in MCT with tooth clearing on the mesiobuccal (MB) root of maxillary first molars. MethodsEighteen maxillary first molar MB roots were scanned, and 2D MinIP and 3D volume-rendered images were reconstructed. Subsequently, the same MB roots were processed by traditional tooth clearing. Images from 2D, 3D, 2D + 3D, and clearing techniques were assessed by 4 endodontists to classify canal configuration and to identify fine anatomic structures such as accessory canals, intercanal communications, and loops. ResultsAll image reformatting techniques in MCT showed detailed configurations and numerous fine structures, such that none were classified as simple type I or II canals; several were classified as types III and IV according to Weine classification or types IV, V, and VI according to Vertucci; and most were nonclassifiable because of their complexity. The clearing images showed less detail, few fine structures, and numerous type I canals. Classification of canal configuration was in 100% intraobserver agreement for all 18 roots visualized by any of the image reformatting techniques in MCT but for only 4 roots (22.2%) classified according to Weine and 6 (33.3%) classified according to Vertucci, when using the clearing technique. ConclusionsThe combination of 2D MinIP and 3D volume-rendered images showed the most detailed canal morphology and fine anatomic structures.

The influence of the blood pressure on the venous cerebral flow measured by magnetic susceptibility (SWI) technique

Susceptibility Weighted Image (SWI) is a Magnetic Resonance Imaging (MRI) technique that combines high spatial resolution and sensitivity to magnetic susceptibility differences between tissues, it is extremely sensitive to venous blood due to its iron content of deoxyhemoglobin. The aim of this study was to evaluate the differences in the cerebral venous vasculature produced by the value’s variation of blood pressure. 20 subjects (10 hypertensive and 10 normotensive patients) underwent a MRI system with field strength of 1.5 T using a synergy head coil (7 channels). The obtained sequences were T1w, T2w-FLAIR, T2* and SWI. The value of Contrast-to-Noise Ratio (CNR) was assessed in MinIP (Minimum Intensity Projection) and Magnitude images, through drawing free hand ROIs in venous structures: Superior Sagittal Sinus (SSS) Internal Cerebral Vein (ICV) and Sinus Confluence (SC). The obtained values were presented in descriptive statistics-quartiles and extremes diagrams. The results were compared between groups. CNR shown higher values for normotensive group in MinIP (108.89 ± 6.907) to ICV; (238.73 ± 18.556) to SC and (239.384 ± 52.303) to SSS. These values are bigger than images from Hypertensive group about 46 au in average. Comparing the results of Magnitude and MinIP images, there were obtained lower CNR values for the hypertensive group. There were differences in the CNR values between both groups, being these values more expressive in the large vessels-SSS and SC. The SWI is a potential technique to evaluate and characterize the blood pressure variation in the studied vessels adding a physiological perspective to MRI and giving a new approach to the radiological vascular studies.

Evaluation of the role of multidetector computed tomography in biliary obstruction

ObjectiveThe aim of the study was to evaluate the role of multidetector computed tomography (MDCT) cholangiography in detecting the cause and the level of biliary obstruction and also evaluating the global performance of combined axial, multiplanar reformatting (MPR), and minimum-intensity projection (MinIP) image reconstructions.Patients and methodsBetween January 2012 and August 2012, this study was performed on 30 patients with clinical and biochemical signs (increased serum levels of bilirubin and/or alkaline phosphatase) suggesting bile duct obstruction who referred to the CT unit in Tanta university hospital from the department of tropical medicine and infectious diseases. These patients were examined by 16-channel CT using a three-phase contrast protocol. The results obtained were compared with the results of histopathological and operative data in patients who underwent surgery.ResultsOur study showed that MDCT cholangiography was accurate in detecting the presence and the level of biliary obstruction in all 30 cases examined (100%), whereas it could define the cause of obstruction correctly in 93.3% of the cases. The overall performance of MPR and MinIP reconstruction in addition to conventional MDCT images showed a synergic effect to conventional axial CT images, showing an improvement in visualization in 83.3% and additional value in 30 and 16% of the cases, respectively.ConclusionMDCT cholangiography is a noninvasive and fast imaging tool in the assessment of patients with biliary obstruction. MPR and MinIP images provide an improvement of visualization of the biliary system and additional diagnostic value for differentiation of benign from malignant biliary obstruction. It represents a valuable supplement to conventional MDCT imaging of hepatopancreatic disorders.