CT findings of idiopathic mesenteric panniculitis and analysis of related factors.

OBJECTIVES: To analyze the computed tomography (CT) findings of idiopathic mesenteric panniculitis and the factors related to its characteristics and to improve the understanding of the disease. METHODS: The imaging findings of 121 patients with mesenteric panniculitis were retrospectively analyzed, along with related factors such as age, sex, and abdominal visceral fat area. RESULTS: Among the 121 patients, two had midgut malrotation, and the lesions were located outside the mesentery on the right side of the abdominal cavity, while the lesions in the other patients were located around the mesentery on the left side of the abdominal cavity, presenting as patchy or patchy fuzzy high-density masses. Annulus fibrosus and/or fatty ring signs were also observed in some patients. Scattered soft tissue nodules were observed around the mesentery in 119 patients. Eight patients had intestinal tract traction and retraction, and one patient had secondary intestinal obstruction. Nearly half of the patients had mesenteric vascular changes, and three had mesenteric vascular thrombosis. Among the 121 patients, there were 89 males and 32 females, aged 22-83, with an average age of 52.14 ± 13.53 years. The distribution range of abdominal visceral fat area (VFA) in 121 patients was 79.85-331.65 cm2. CONCLUSION: Mesenteric panniculitis has certain characteristic imaging findings that can be accompanied by often ignored changes in the mesenteric blood vessels and intestinal tubes. Intestinal obstruction and mesenteric vascular thrombosis are rare complications, and their primary causes are often overlooked. Mesenteric panniculitis was correlated with sex, age, and VFA.

Application effect of multi-slice spiral CT angiography combined with MRI in the diagnosis of cerebral aneurysm.

To investigate the clinical value of multi-slice spiral computed tomography (CT) angiography (MSCTA) combined with MRI in the diagnosis of cerebral aneurysm. A total of 90 patients with cerebral aneurysms diagnosed by DSA were selected as the subjects of this study. Another 30 patients with cerebral infarction were selected as negative controls (NC). Before diagnosis, all patients underwent comprehensive examination using MSCTA and MRI. The results of the comparison and the clinical data of all patients were retrospectively analyzed. MSCTA and MRI examinations can clearly show the specific location, shape, size and anatomical relationship with surrounding tissues of cerebral aneurysms. MSCTA diagnosed 82 patients and missed or misdiagnosed 8 patients in the 90 patients with cerebral aneurysm. The diagnostic sensitivity and accuracy of MSCTA were 91.1 (82/90) and 89.2 (107/120), respectively. MRI examination diagnosed 87 patients and missed or misdiagnosed 3 patients in the 90 patients with cerebral aneurysm. The diagnostic sensitivity and accuracy of MRI were 96.7 (87/90) and 96.7 (116/120), respectively. The sensitivity and accuracy of MSCTA combined with MRI were 100.0 (90/90) and 99.2 (119/120), respectively. MSCTA combined with MRI can not only display the whole picture of brain tissue, but also display the size, shape and relationship with the parent vessel of the aneurysm. The combination of MSCTA and MRI has high sensitivity and accuracy in diagnosing intracranial aneurysms, which provides a promising diagnostic protocol for patients with aneurysms.

Impact of bowtie filter and detector collimation on multislice CT scatter profiles: A simulation study.

PURPOSE: To investigate via Monte Carlo simulations, the impact of scan subject size, antiscatter grid (ASG), collimator size, and bowtie filter on the distribution of scatter radiation in a typical realistically modeled third generation 16 slice diagnostic computed tomography (CT) scanner. METHODS: Full radiation transport was simulated with Geant4 in a realistic CT scanner geometric model, including the imaging phantom, bowtie filter (BTF), collimators and detector assembly, except for the ASGs. An analytical method was employed to quantify the probable transmission through the ASG of each photon intersecting the detector array. Normalized scatter profiles (NSP) and scatter-to-primary-ratio (SPR) profiles were simulated for 90 and 140 kVp beams for different size phantoms and slice thicknesses. The impact of CT scatter on the reconstructed attenuation coefficient factor was also studied as were the modulating effects of phantom- and patient-tissue heterogeneities on scatter profiles. A method to characterize the relative spatial frequency content of sinogram signals was developed to assess the latter. RESULTS: For the 21.4-cm diameter phantom, NSP and SPR increase linearly with collimator opening for both tube potentials, with the 90 kVp scan exhibiting slightly larger NSP and SPR. The BTF modestly modulates scatter under the phantom center, reducing the prominent off-axis lobes by factors of 1.1-1.3. The ASG reduces scatter on the central axis NSP threefold, and reduces scatter at the detectors outside the phantom shadow by factors of 25 to 500. For the phantoms with diameters of 27 and 32 cm, the scatter increases roughly three- and fourfold, respectively, demonstrating that scatter monotonically increases with phantom size, despite deployment of the ASG and BTF. In the absence of a scan subject, the ASG reduces the signal profile arising photons scattered by the BTF. Without ASG, the in-air scatter profile is relatively flat compared to the scatter profile when the ASG is present. For both 90 and 140 kVp photon spectra, the calculated attenuation coefficient decreases linearly with increasing collimation size. For both homogeneous and heterogeneous objects, NSPs are dominated by low spatial frequency content compared to the primary signal. However, the SPR, which quantifies the local magnitude of nonlinear detector response and is dominated by the high frequency content of the primary profile, can contribute strongly to high-spatial frequency streaking artifacts near high-density structures in reconstructed image artifacts. CONCLUSION: Public-domain Monte Carlo codes, Geant-4 in particular, is a feasible method for characterizing CT detector response to scattered- and off-focal radiation. Our study demonstrates that the ASG substantially reduces the scatter radiation and reshapes scatter-radiation profiles and affects the accuracy with which the detector array can measure narrow-beam attenuation due its inability to distinguish between true uncollided primary and narrow-angle coherently scattered photons. Hence, incorporating the impact of detector array collimation into the forward-projection signal formation models used by iterative reconstruction algorithms is necessary to use CT for accurately characterizing material properties. While tissue heterogeneities exercise a modest influence on local NPS shape and magnitude, they do not add significant high spatial frequency content.

Quantification of Metal Artefacts from Orthodontic Brackets in CT Images: A Modified Method

@#Any metallic object within the CT scanning field can produce metal artefacts, which will degrade the diagnostic image quality. Previous methods described for quantifying this kind of artefacts were complicated and difficult to reproduce. The purpose of this study was to introduce a new rapid method for quantifying the artefacts produced in craniofacial CT images. This is an in-vitro experimental study. Four different compositions of orthodontic brackets were bonded consecutively in the tooth surfaces of a cadaveric skull head. All scans were performed by a single operator using the same CT machine followed by a standard scanning protocol. Artefact intensity for all data sets was quantified by following a modified method with a freely available open-source software ImageJ. All datasets were duplicated where metal artefacts were quantified according to the previous conventional method. Statistical analysis included independent samples t-test for validation and intraclass correlation coefficient (ICC) with a 95% confidence interval for both intra- and inter-examiner reliability. The modified method of measuring artefact score exhibited excellent intra (0.997–0.941) and inter-rater (0.996–0.905) reliability. In addition, no significant difference (p = 0.072) of mean artefact score was noted between the groups measured by the modified method and the conventional method. This modified method for measuring the artefact intensity is valid and reliable.

Anomalous coronary artery anatomy with a single coronary ostium arising from the right coronary: a case report and literature review.

Purpose: This article reports the case of a single coronary artery with origin from a single ostium in the right sinus of Valsalva (RSOV) with an anomalous course of the left coronary artery anterior to the pulmonary trunk. Results: We present the case of an anomalous single coronary artery detected incidentally during routine coronary computed tomography (CT) angiography performed by a multislice CT method, using a 64-detector-row scanner. The CT examination revealed that the patient had a single large right coronary artery arising from the right sinus of Valsalva, dividing into the right coronary artery, left main coronary artery (LMCA), and left circumflex artery (LCX). The LMCA turned anteriorly in front of the pulmonary outflow tract, reaching the atrioventricular groove. The LCX artery passed posterior to the aorta (retro-aortic) and then between the left atrium and left ventricular outflow tract to reach its normal course on the left side. Conclusion: We present a rare case of single coronary artery congenital anomaly from the Makkah region of Saudi Arabia. This kind of coronary artery anomaly in the absence of stenosis could remain silent and asymptomatic.

Use of Multislice CT for Investigation of Occult Geriatric Hip Fractures and Impact on Timing of Surgery.

INTRODUCTION: The National Institute of Health and Clinical Excellence guidelines in the United Kingdom recommend magnetic resonance imaging (MRI) as the first-line investigation for radiographically occult hip fractures, if available within 24 hours. In our department, however, multislice computerized tomography (MSCT) is instead used as a first-line investigation due to significant delays associated with obtaining MRI. Our aim was to determine the validity and practicality of MSCT for diagnosis of occult hip fractures and its impact on timing of surgery. MATERIALS AND METHODS: We retrospectively analyzed medical records and imaging for consecutive patients who underwent MSCT to investigate occult hip fractures between January 2014 and October 2016. We reviewed subsequent imaging and reattendances for patients with negative MSCT to exclude initially missed fractures. RESULTS: Two hundred six patients underwent MSCT to investigate occult hip fracture during the study period. Hip fractures were identified in 59 patients, comprising 35 (59.3%) subcapital, 12 (20.0%) intertrochanteric, 8 (13.6%) transcervical, and 4 (6.8%) basicervical fractures. One missed hip fracture was identified: a patient with a negative MSCT was further investigated with MRI that demonstrated acute subcapital hip fracture. Multislice computerized tomography was obtained within 24 hours of initial radiograph in 145 (70.4%) patients. A total of 44.5% of occult hip fractures had surgery within the nationally recommended 36 hours of admission (hospital average for all hip fractures was 76.4% over the same period). DISCUSSION AND CONCLUSIONS: Multislice computerized tomography is a pragmatic approach to investigate the majority of occult hip fractures in a timely manner and minimize associated delay to surgery. However it cannot completely exclude the diagnosis, especially in abnormal anatomy. The lack of a true gold standard comparison (ie, MRI) means a true sensitivity and specificity cannot be calculated, although can be cautiously estimated by lack of subsequent reattendance or investigation. Further prospective randomized CT versus MRI trials are required.

Multislice computed tomography/contrast-enhanced ultrasound image fusion as a tool for evaluating unclear renal cysts.

Ultrasonography is a generally accepted imaging technique for diagnosing and monitoring cystic renal lesions. The widely used Bosniak classification (I-IV) categorizes renal cystic lesions into five distinctive groups according to ultrasonography and computed tomography (CT) image criteria. For solid renal lesions, determination of vascularity is discriminatory for malignancy in most instances. In indeterminate cases, contrast-enhanced ultrasound (CEUS) and magnetic resonance imaging/CT-ultrasound image fusion are able to detect and characterize difficult pathologies, with superior performance to either technique alone. In contrast to multislice CT (MS-CT), ultrasound image fusion is a real-time imaging technique that can be used in combination with other cross-sectional imaging modalities. This technical note describes state-of-the-art image fusion of CEUS and MS-CT to detect and characterize unclear renal pathologies.

Multislice computed tomography/contrast-enhanced ultrasound image fusion as a tool for evaluating unclear renal cysts

Ultrasonography is a generally accepted imaging technique for diagnosing and monitoring cystic renal lesions. The widely used Bosniak classification (I-IV) categorizes renal cystic lesions into five distinctive groups according to ultrasonography and computed tomography (CT) image criteria. For solid renal lesions, determination of vascularity is discriminatory for malignancy in most instances. In indeterminate cases, contrast-enhanced ultrasound (CEUS) and magnetic resonance imaging/CT-ultrasound image fusion are able to detect and characterize difficult pathologies, with superior performance to either technique alone. In contrast to multislice CT (MS-CT), ultrasound image fusion is a real-time imaging technique that can be used in combination with other cross-sectional imaging modalities. This technical note describes state-of-the-art image fusion of CEUS and MS-CT to detect and characterize unclear renal pathologies.

On the data acquisition, image reconstruction, cone beam artifacts, and their suppression in axial MDCT and CBCT - A review.

PURPOSE: In the clinic, computed tomography (CT) has evolved into an essential modality for diagnostic imaging by multidetector row CT (MDCT) and image guided intervention by cone beam CT (CBCT). Recognizing the increasing importance of axial MDCT/CBCT in clinical and preclinical applications, and the existence of CB artifacts in MDCT/CBCT images, we provide a review of CB artifacts' root causes, rendering mechanisms and morphology, and possible solutions for elimination and/or reduction of the artifacts. METHODS: By examining the null space in Radon and Fourier domain, the root cause of CB artifacts (i.e., data insufficiency) in axial MDCT/CBCT is analytically investigated, followed by a review of the data sufficiency conditions and the "circle +" source trajectories. The rendering mechanisms and morphology of CB artifacts in axial MDCT/CBCT and their special cases (e.g., half/short scan and full scan with latitudinally displaced detector) are then analyzed, followed by a survey of the potential solutions to suppress the artifacts. The phenomenon of imaged zone indention and its variation over FBP, BPF/DBPF, two-pass and iterative CB reconstruction algorithms and/or schemes are discussed in detail. RESULTS: An interdomain examination of the null space provides an insightful understanding of the root cause of CB artifacts in axial MDCT/CBCT. The decomposition of CB artifacts rendering mechanisms facilitates understanding of the artifacts' behavior under different conditions and the potential solutions to suppress them. An inspection of the imaged zone intention phenomenon provides guidance on the design and implementation of CB image reconstruction algorithms and schemes for CB artifacts suppression in axial MDCT/CBCT. CONCLUSIONS: With increasing importance of axial MDCT/CBCT in clinical and preclinical applications, this review article can update the community with in-depth information and clarification on the latest progress in dealing with CB artifacts and thus increase clinical/preclinical confidence.

Right Pulmonary Venous Atresia: A Rare Cause for Recurrent Unilateral Pneumonia.

Recurrent unilateral pneumonia poses a diagnostic dilemma for all paediatricians. Isolated pulmonary venous atresia is an uncommon entity, which presents with recurrent unilateral pulmonary infections, dyspnoea on exertion and haemoptysis. It is associated with significant mortality and morbidity. Owing to rarity of condition, there may be some difficulties in the diagnosis and therapy. Pulmonary angiography is the investigation of choice. However, the current multislice CT scanners may obviate the need for pulmonary angiography. We report a two-year-old child with this rare congenital malformation and discuss diagnostic modalities and management options.

Recognition of a rare intrathoracic rib with computed tomography: a case report.

One of the uncommon congenital variations is intrathoracic rib which a normal, a bifid, or an accessory rib lies within the thoracic cavity that is founded accidentally. Clinically, in most cases they are without symptoms; however, it may cause intrathoracic problems therefore it is important for radiologists and physicians to identify to prevent of excessive intervention and treatment during imaging diagnostic techniques of thoracic problems. In this report, we provide the case of a rare presentation of an intrathoracic rib in a 3-year-old boy arising from the inferior portion of a second rib based on findings from computed tomography. To our knowledge, this is only the second reported case of this type of intrathoracic rib that demonstrated with computed tomography.

Utility of fusion volumetric images from computed tomography and magnetic resonance imaging for localizing the mandibular canal.

OBJECTIVES: The purpose of this study was to investigate whether CT/MRI fusion volumetric images can improve the detectability of the mandibular canal (MC) compared with CT alone. METHODS: Images of 31 lesions within or close to the mandible using both multislice CT (MSCT) and MRI were gathered from our imaging archives. All lesions underwent MSCT and three-dimensional volumetric interpolated breath-hold examination (3D-VIBE) MRI. Of the 62 hemimandibles, 13 hemimandibles were excluded because the MC passed through a lesion. The remaining 49 hemimandibles were included in this study. Each hemimandible was divided into 3 areas (premolar, molar and retromolar), and 147 areas were evaluated. First, the visibility of the MC on CT or its neurovascular bundle (NVB) on 3D-VIBE was evaluated. Second, in areas in which both the MC and NVB were visible, the relative locations of the NVB on MRI and the position of the MC on CT were assessed using CT/MRI fusion volumetric images. RESULTS: The MC and NVB were clearly visible in 100 (68%) and 144 (98%) of 147 areas on CT and MRI, respectively. All NVBs and MCs were in identical locations, and the NVB on MRI was the same size or smaller than the MC on CT in 79 and 21 areas, respectively. CONCLUSIONS: 3D-VIBE MRI can accurately depict the NVB. Compared with CT alone, CT/MRI fusion volumetric imaging improves MC detectability.

One-stop shop assessment for atrial septal defect closure using 256-slice coronary CT angiography.

OBJECTIVES: To investigate the feasibility and accuracy of measurement of the pulmonary to systemic blood flow ratio (Qp/Qs) and defect and rim sizes in secundum atrial septal defects (ASDs) using 256-slice CT, compared to the reference transoesophageal echocardiography (TEE) and right heart catheterization (RHC) measurements. METHODS: Twenty-three consecutive adult patients with secundum ASDs who underwent retrospective ECG-gated coronary CT angiography (CCTA), TEE and RHC were enrolled in this study. Right ventricular (RV) and left ventricular (LV) stroke volumes (SV) were calculated by biventricular volumetry of CCTA. Qp/Qs-CT was defined as RVSV/LVSV. The sizes of the defect and rim were measured by multi-planar reconstruction CT images. Correlations between Qp/Qs-CT and Qp/Qs-RHC and between the defect diameter obtained by CT and TEE were analyzed by Pearson's coefficient analysis. Rim sizes by CT and TEE were compared by paired t-test. RESULTS: Qp/Qs-CT was significantly correlated with Qp/Qs-RHC (r = 0.83, p < 0.0001), and the defect diameter by CT was significantly correlated with that by TEE (r = 0.95, p < 0.0001). There was no significant difference between CT and TEE in measurements of rim size. CONCLUSIONS: 256-slice CCTA allows measuring Qp/Qs and size of defects and rims in patients with secundum ASDs, accomplishing pretreatment evaluation non-invasively and comprehensively. KEY POINTS: • Quantification of left-to-right shunting can be performed reliably and accurately by CT. • The sizes of defects and rims can be measured accurately using 256-slice CT. • 256-slice CT permits pretreatment evaluation of ASD non-invasively and comprehensively.

Preoperative 3D and 4D-CT imaging using 640-Multislice CT (640-MSCT) in diagnosis of female urethral diverticulum.

OBJECTIVE: To determine the sensitivity and specificity of 640-Multislice CT (640-MSCT) in diagnosing the female UD. MATERIALS AND METHODS: We investigated 16 patients with symptomatic UDs preoperatively in our hospital from August 2010 to March 2016. The patients' average age was 38.8 years. All patients were performed 640-MSCT of pelvis; then, 3D and 4D images were reconstructed preoperatively. RESULTS: In 3D and 4D-CT images, out of 16 patients, thirteen patients had one ostium, two had 2 ostia and one had 3 ostia. Out of those thirteen patients, eight patients' ostia were located at 5 o'clock and five patients' at 7 o'clock. Patients with 2 ostia location were at 5 and 6 o'clock and 5 and 7 o'clock, respectively. Patients with 3 ostia location were at 5, 6 and 7 o'clock. The mean distance from the bladder neck to the ostia was 22.5 mm. The shape of UD was out-pouching in 11 patients (68.8%), U-shaped in four patients (25.0%) and circumferential in 1 patient (6.2%). The CT findings were confirmed by surgical findings. CONCLUSIONS: 640-MSCT is a useful tool in identifying UD's shape and ostium (including number, location) before operation. Preoperative 640-MSCT should be an adaptable modality for clinically suspected UD patients. ADVANCES IN KNOWLEDGE: Several imaging methods have been used to diagnose female UD. 640-MSCT may be more suitable to diagnose it for its higher sensitivity and specificity in diagnosis of female UD, especially in identifying UD's shape and number and location of ostium.

Recognition of a rare intrathoracic rib with computed tomography: a case report / 대한해부학회지

One of the uncommon congenital variations is intrathoracic rib which a normal, a bifid, or an accessory rib lies within the thoracic cavity that is founded accidentally. Clinically, in most cases they are without symptoms; however, it may cause intrathoracic problems therefore it is important for radiologists and physicians to identify to prevent of excessive intervention and treatment during imaging diagnostic techniques of thoracic problems. In this report, we provide the case of a rare presentation of an intrathoracic rib in a 3-year-old boy arising from the inferior portion of a second rib based on findings from computed tomography. To our knowledge, this is only the second reported case of this type of intrathoracic rib that demonstrated with computed tomography.

Prognostic value of the ratio between prosthesis area and indexed annulus area measured by MultiSlice-CT for transcatheter aortic valve implantation procedures.

BACKGROUND: Postprocedural aortic regurgitations following transcatheter aortic valve implantation (TAVI) procedures remain an issue. Benefit of oversizing strategies to prevent them isn't well established. We compared different level of oversizing in our cohort of consecutive patients to address if severe oversizing compared to normal sizing had an impact on post-procedural outcomes. METHODS: From January 2010 to August 2013, consecutive patients were referred for TAVI with preoperative Multislice-CT (MSCT) and the procedures were achieved using Edwards Sapien(®) or Corevalve devices(®). Retrospectively, according to pre-procedural MSCT and the valve size, patients were classified into three groups: normal, moderate and severe oversizing; depending on the ratio between the prosthesis area and the annulus area indexed and measured on MSCT. Main endpoint was mid-term mortality and secondary endpoints were the Valve Academic Research Consortium (VARC-2) endpoints. RESULTS: Two hundred and sixty eight patients had a MSCT and underwent TAVI procedure, with mainly Corevalve(®). While all-cause and cardiovascular mortality rates were similar in all groups, post-procedural new pacemaker (PM) implantation rate was significantly higher in the severe oversizing group (P = 0.03), while we observed more in-hospital congestive heart-failure (P = 0.02) in the normal sizing group. There was a trend toward more moderate to severe aortic regurgitation (AR) in the normal sizing group (P = 0.07). CONCLUSIONS: Despite a higher rate of PM implantation, oversizing based on this ratio reduces aortic leak with lower rates of post-procedural complications and a similar mid-term survival.

Smoking cessation results in a clinical lung cancer screening program.

BACKGROUND: Lung cancer screening may provide a "teachable moment" for promoting smoking cessation. This study assessed smoking cessation and relapse rates among individuals undergoing follow-up low-dose chest computed tomography (CT) in a clinical CT lung screening program and assessed the influence of initial screening results on smoking behavior. METHODS: Self-reported smoking status for individuals enrolled in a clinical CT lung screening program undergoing a follow-up CT lung screening exam between 1st February, 2014 and 31st March, 2015 was retrospectively reviewed and compared to self-reported smoking status using a standardized questionnaire at program entry. Point prevalence smoking cessation and relapse rates were calculated across the entire population and compared with exam results. All individuals undergoing screening fulfilled the National Comprehensive Cancer Network Clinical Practice Guidelines in Oncology: Lung Cancer Screening v1.2012(®) high-risk criteria and had an order for CT lung screening. RESULTS: A total of 1,483 individuals underwent a follow-up CT lung screening exam during the study interval. Smoking status at time of follow-up exam was available for 1,461/1,483 (98.5%). A total of 46% (678/1,461) were active smokers at program entry. The overall point prevalence smoking cessation and relapse rates were 20.8% and 9.3%, respectively. Prior positive screening exam results were not predictive of smoking cessation (OR 1.092; 95% CI, 0.715-1.693) but were predictive of reduced relapse among former smokers who had stopped smoking for 2 years or less (OR 0.330; 95% CI, 0.143-0.710). Duration of program enrollment was predictive of smoking cessation (OR 0.647; 95% CI, 0.477-0.877). CONCLUSIONS: Smoking cessation and relapse rates in a clinical CT lung screening program rates are more favorable than those observed in the general population. Duration of participation in the screening program correlated with increased smoking cessation rates. A positive exam result correlated with reduced relapse rates among smokers recently quit smoking.

Examination using modern low dose Multislice-CT (MS-CT) in otorhinolaryngology in a six-week-old baby.

A 6-week-old girl suffered from a growing and recurrently bleeding mass of unrecognizable origin, obstructing the left nose. Using low-dose Multislice-CT the exact diagnostic localization could be found within one minute in the sleeping baby without sedation or general anesthesia. The result of this imaging enabled the successful complete microscopic removal of a hemangioma from the left inferior turbinate. Follow-up after 15 months showed normal nasal finds.