Multidetector Computed Tomography Imaging Research Articles

Labeling Vertebrae with Two-dimensional Reformations of Multidetector CT Images: An Adversarial Approach for Incorporating Prior Knowledge of Spine Anatomy.

To use and test a labeling algorithm that operates on two-dimensional reformations, rather than three-dimensional data to locate and identify vertebrae. The authors improved the Btrfly Net, a fully convolutional network architecture described by Sekuboyina et al, which works on sagittal and coronal maximum intensity projections (MIPs) and augmented it with two additional components: spine localization and adversarial a priori learning. Furthermore, two variants of adversarial training schemes that incorporated the anatomic a priori knowledge into the Btrfly Net were explored. The superiority of the proposed approach for labeling vertebrae on three datasets was investigated: a public benchmarking dataset of 302 CT scans and two in-house datasets with a total of 238 CT scans. The Wilcoxon signed rank test was employed to compute the statistical significance of the improvement in performance observed with various architectural components in the authors' approach. On the public dataset, the authors' approach using the described Btrfly Net with energy-based prior encoding (Btrflype-eb) network performed as well as current state-of-the-art methods, achieving a statistically significant (P < .001) vertebrae identification rate of 88.5% ± 0.2 (standard deviation) and localization distances of less than 7 mm. On the in-house datasets that had a higher interscan data variability, an identification rate of 85.1% ± 1.2 was obtained. An identification performance comparable to existing three-dimensional approaches was achieved when labeling vertebrae on two-dimensional MIPs. The performance was further improved using the proposed adversarial training regimen that effectively enforced local spine a priori knowledge during training. Spine localization increased the generalizability of our approach by homogenizing the content in the MIPs.Supplemental material is available for this article.© RSNA, 2020.

Computed tomographic and ultrasonographic findings of abdominal arterial pseudoaneurysms caused by systemic mycosis in dogs

To describe multidetector CT and ultrasonographic characteristics of abdominal arterial pseudoaneurysms (segmental dilatations of an artery with a ruptured tunica intima) arising secondary to systemic mycosis in dogs. Retrospective study on dogs with confirmed histological diagnosis of a fungal pseudoaneurysm and the availability of multidetector CT or ultrasound images. At the time of admission, the three dogs included in this study demonstrated segmental arterial dilation, irregular arterial wall thickening, and increased echogenicity or attenuation within the local perivascular fat on ultrasound and multidetector CT images. Follow-up examinations revealed progressive increase in arterial wall thickening and saccular dilation with formation of a pseudoaneurysm in affected vessels of two dogs. Multidetector CT and ultrasonography can be useful imaging modalities in the diagnosis and monitoring of abdominal arterial pseudoaneurysms caused by systemic mycosis.

Small airways pathology in idiopathic pulmonary fibrosis: a retrospective cohort study

The observation that patients with idiopathic pulmonary fibrosis (IPF) can have higher than normal expiratory flow rates at low lung volumes led to the conclusion that the airways are spared in IPF. This study aimed to re-examine the hypothesis that airways are spared in IPF using a multiresolution imaging protocol that combines multidetector CT (MDCT), with micro-CT and histology. This was a retrospective cohort study comparing explanted lungs from patients with severe IPF treated by lung transplantation with a cohort of unused donor (control) lungs. The donor control lungs had no known lung disease, comorbidities, or structural lung injury, and were deemed appropriate for transplantation on review of the clinical files. The diagnosis of IPF in the lungs from patients was established by a multidisciplinary consensus committee according to existing guidelines, and was confirmed by video-assisted thoracic surgical biopsy or by pathological examination of the contralateral lung. The control and IPF groups were matched for age, sex, height, and bodyweight. Samples of lung tissue were compared using the multiresolution imaging approach: a cascade of clinical MDCT, micro-CT, and histological imaging. We did two experiments: in experiment 1, all the lungs were randomly sampled; in experiment 2, samples were selected from regions of minimal and established fibrosis. The patients and donors were recruited from the Katholieke Universiteit Leuven (Leuven, Belgium) and the University of Pennsylvania Hospital (Philadelphia, PA, USA). The study took place at the Katholieke Universiteit Leuven, and the University of British Columbia (Vancouver, BC, Canada). Between Oct 5, 2009, and July 22, 2016, explanted lungs from patients with severe IPF (n=11), were compared with a cohort of unused donor (control) lungs (n=10), providing 240 samples of lung tissue for comparison using the multiresolution imaging approach. The MDCT specimen scans show that the number of visible airways located between the ninth generation (control 69 [SD 22] versus patients with IPF 105 [33], p=0·0023) and 14th generation (control 9 [6] versus patients with IPF 49 [28], p<0·0001) of airway branching are increased in patients with IPF, which we show by micro-CT is due to thickening of their walls and distortion of their lumens. The micro-CT analysis showed that compared with healthy (control) lung anatomy (mean 5·6 terminal bronchioles per mL [SD 1·6]), minimal fibrosis in IPF tissue was associated with a 57% loss of the terminal bronchioles (mean 2·4 terminal bronchioles per mL [SD 1·0]; p<0·0001), the appearance of fibroblastic foci, and infiltration of the tissue by inflammatory immune cells capable of forming lymphoid follicles. Established fibrosis in IPF tissue had a similar reduction (66%) in the number of terminal bronchioles (mean 1·9 terminal bronchioles per mL [SD 1·4]; p<0·0001) and was dominated by increased airspace size, Ashcroft fibrosis score, and volume fractions of tissue and collagen. Small airways disease is a feature of IPF, with significant loss of terminal bronchioles occuring within regions of minimal fibrosis. On the basis of these findings, we postulate that the small airways could become a potential therapeutic target in IPF. Katholieke Universiteit Leuven, US National Institutes of Health, BC Lung Association, and Genentech.

Value of multidetector computed tomography for the differentiation of delayed aseptic and septic complications after total hip arthroplasty.

The differentiation between delayed aseptic and septic complications of total hip arthroplasty is crucial to allow appropriate surgical planning and timely antimicrobial treatment. The aim of this study was to investigate the utility of multidetector computed tomography (CT) findings to diagnose aseptic mechanical loosening, granulomatous reaction, and periprosthetic joint infection in patients who underwent total hip arthroplasty before revision surgery. Ninety-six consecutive patients with a clinical suspicion of periprosthetic complications underwent revision surgery over an 8-year period. All patients had been evaluated preoperatively using multidetector CT without contrast media. Two blinded musculoskeletal radiologists reviewed multidetector CT images, including periprosthetic soft-tissue accumulation, prosthetic acetabular malposition, periprosthetic osteolysis, enlarged iliac lymph nodes, and heterotopic ossification. Risk factors for aseptic and septic loosening were identified using multivariate analysis. Multidetector CT-related variables independently associated with periprosthetic joint infection were high periprosthetic soft-tissue accumulation, periprosthetic osteolysis without expansile periosteal reaction and enlarged iliac lymph nodes. On the other hand, the absence of the following radiological signs: low or high periprosthetic soft-tissue accumulation, mild or severe periprosthetic osteolysis, and enlarged iliac lymph nodes, were predictors of aseptic mechanical loosening. Low periprosthetic soft-tissue accumulation, severe periprosthetic osteolysis with expansile periosteal reaction, and mild acetabular malposition were significant variables associated with granulomatosis. Multidetector CT findings are useful to differentiate between aseptic and septic complications before revision surgery. The presence of osteolysis with expansile periosteal reaction appeared to be a time-dependent variable.

Evaluation of human epidermal growth factor receptor 2 status of breast cancer using preoperative multidetector computed tomography with deep learning and handcrafted radiomics features.

ObjectiveTo evaluate the human epidermal growth factor receptor 2 (HER2) status in patients with breast cancer using multidetector computed tomography (MDCT)-based handcrafted and deep radiomics features.MethodsThis retrospective study enrolled 339 female patients (primary cohort, n=177; validation cohort, n=162) with pathologically confirmed invasive breast cancer. Handcrafted and deep radiomics features were extracted from the MDCT images during the arterial phase. After the feature selection procedures, handcrafted and deep radiomics signatures and the combined model were built using multivariate logistic regression analysis. Performance was assessed by measures of discrimination, calibration, and clinical usefulness in the primary cohort and validated in the validation cohort.ResultsThe handcrafted radiomics signature had a discriminative ability with a C-index of 0.739 [95% confidence interval (95% CI): 0.661−0.818] in the primary cohort and 0.695 (95% CI: 0.609−0.781) in the validation cohort. The deep radiomics signature also had a discriminative ability with a C-index of 0.760 (95% CI: 0.690−0.831) in the primary cohort and 0.777 (95% CI: 0.696−0.857) in the validation cohort. The combined model, which incorporated both the handcrafted and deep radiomics signatures, showed good discriminative ability with a C-index of 0.829 (95% CI: 0.767−0.890) in the primary cohort and 0.809 (95% CI: 0.740−0.879) in the validation cohort.ConclusionsHandcrafted and deep radiomics features from MDCT images were associated with HER2 status in patients with breast cancer. Thus, these features could provide complementary aid for the radiological evaluation of HER2 status in breast cancer.

Very deep super-resolution for efficient cone-beam computed tomographic image restoration.

PurposeAs cone-beam computed tomography (CBCT) has become the most widely used 3-dimensional (3D) imaging modality in the dental field, storage space and costs for large-capacity data have become an important issue. Therefore, if 3D data can be stored at a clinically acceptable compression rate, the burden in terms of storage space and cost can be reduced and data can be managed more efficiently. In this study, a deep learning network for super-resolution was tested to restore compressed virtual CBCT images.Materials and MethodsVirtual CBCT image data were created with a publicly available online dataset (CQ500) of multidetector computed tomography images using CBCT reconstruction software (TIGRE). A very deep super-resolution (VDSR) network was trained to restore high-resolution virtual CBCT images from the low-resolution virtual CBCT images.ResultsThe images reconstructed by VDSR showed better image quality than bicubic interpolation in restored images at various scale ratios. The highest scale ratio with clinically acceptable reconstruction accuracy using VDSR was 2.1.ConclusionVDSR showed promising restoration accuracy in this study. In the future, it will be necessary to experiment with new deep learning algorithms and large-scale data for clinical application of this technology.

Male Genital Organs in the Red Fox (Vulpes vulpes); Macroanatomic and Three-dimentional Reconstruction Aspect

In this study, it was aimed to describe to the genital organs, the macroanatomical aspect and three- dimentional (3D) reconstruction of penis and os penis using multidetector computed tomography (MDCT) images in the male red fox (Vulpes vulpes). Six dead male red foxes were used as material. After MDCT images of the penis were obtained, they were reconstructed using a 3D modeling program (Mimics) by overlapping the images. Morphometric measurements were taken from reconstructed model of the penis and os penis. Dissections of foxes were carefully carried out under the loupes. Testis, epididymis and penis were measured from different places. In terms of anatomical aspect, in the red foxes were determined to ovoid testis and extend horizontally into the scrotum. The accessory genital glands were only prostate. The prostate was located to surround the urethra. The spongios body of penis had os penis which the urethra was pass through. The length of the penis obtained by mimics program and digital calliper were not difference. These results may contribute to the lack of the literature about male genital anatomy of the fed fox. It is thought that this study, using 3D reconsruction techniques could make anatomical studies easier to do without harming on wild animals.

Effect of the intervertebral disc on vertebral bone strength prediction: a finite-element study

BACKGROUND CONTEXTOsteoporotic vertebral fractures (OVFs) are a prevalent skeletal condition in the elderly but the mechanism behind these fractures remain unclear due to the complex biomechanical interplay between spinal segments such as the vertebra and intervertebral discs (IVDs). PURPOSETo investigate the biomechanical influence of IVDs by (1) comparing finite element (FE)-predicted failure load with experimentally measured failure load of functional spinal units (FSUs) and (2) comparing this correlation with those of FE-predicted failure load and bone mineral density (BMD) of the single central vertebra with experimentally measured failure load. STUDY DESIGNA computational biomechanical analysis. PATIENT SAMPLETen thoracic FSUs consisting of a central vertebra, the adjacent IVDs, and the upper and lower halves of the adjacent vertebrae were harvested from formalin-fixed human donors (4 males, 6 females; mean age of 82±9 years). OUTCOME MEASURESThe outcome measures included the prediction of vertebral strength and determination of BMD in FSUs and the single central vertebra and the correlation of both measures with experimentally measured vertebral strength of the FSUs. METHODSThe FSUs underwent clinical multidetector computed tomography (MDCT) (spatial resolution: 250×250×600 μm3). BMD was determined for the FSUs from the MDCT images of the central vertebrae. FE-predicted failure load was calculated in the single central vertebra of the FSUs alone and the entire FSUs. Experimentally measured failure load of the FSUs was determined in a uniaxial biomechanical test. RESULTSBMD of the central vertebrae correlated significantly with experimentally measured failure load (R2=0.66, p<.02), whereas FE-predicted failure load of the central vertebra showed no significant correlation with experimentally measured failure load (p=.07). However, FE-predicted failure load of FSUs best predicted experimentally measured failure load of FSUs (R2=0.93, p<.0001). CONCLUSIONSThis study demonstrated that routine clinical MDCT images can be an accurate and feasible tool for prediction of OVFs using patient-specific FE analysis of FSU models. CLINICAL SIGNIFICANCEImproved management of OVFs is essential amidst current clinical challenges. Implementation of a vertebral strength assessment tool could result in more accurate prediction of osteoporotic fracture risk and aid clinicians with better targeted early treatment strategies.

Is cranial multi-detector computed tomography imaging valuable for stature estimation in Egyptian population?

Background and objectivesStature estimation is an initial and essential component of any medico-legal investigations. However, it becomes more challenging when only skull remains are available. So, the goal of this study is to assess stature estimation using cranial multi-detector computed tomography (MDCT) images in a sample of the Egyptian population.MethodsThis clinical study was conducted on 150 Egyptian subjects underwent cranium MDCT with age ranged from 21 to 60 years. The measurements used were maximum cranial breadth, minimum frontal breadth, upper facial breadth, bizygomatic breadth, orbital height, orbital breadth, parietal chord, bimastoidale, maximum cranial length, basion-bregma height, cranial base length, and basion-prosthion length.ResultsThe results revealed that stature and craniofacial measurements of males were significantly higher than those of females, all measurements were significantly positively correlated with stature in pooled cases, but the correlation coefficient differs in separate sex. Simple linear regression for stature estimation showed that the least standard error of estimate (SEE) values for the regression equations obtained when using bizygomatic breadth in pooled cases (7.9 cm) and in males only (5.7 cm), while in females using parietal chord had the least SEE (6.8 cm). Using multiple and stepwise regression analysis reported lower SEE values than simple linear regression analysis.ConclusionOn the basis of this study, it is concluded that the cranial measurements obtained from MDCT images have limited utility in stature estimation among Egyptians, but could be used as an alternative method in cases where the best predictors, such as long bones, are not available.

Prediction of Histopathologic Growth Patterns of Colorectal Liver Metastases with a Noninvasive Imaging Method.

To predict histopathologic growth patterns (HGPs) in colorectal liver metastases (CRLMs) with a noninvasive radiomics model. Patients with chemotherapy-naive CRLMs who underwent abdominal contrast-enhanced multidetector CT (MDCT) followed by partial hepatectomy between January 2007 and January 2019 from two institutions were included in this retrospective study. Hematoxylin- and eosin-stained histopathologic sections of CRLMs were reviewed, with HGPs defined according to international consensus. Lesions were divided into training and validation datasets based on patients' sources. Radiomic features were extracted from pre- and post-contrast (arterial and portal venous) phase MDCT images, with review focusing on the segmented tumor-liver interface zones of CRLMs. Minimum redundancy maximum relevance and decision tree methods were used for radiomics modeling. Multivariable logistic regression analyses and ROC curves were used to assess the predictive performance of these models in predicting HGP types. A total of 126 CRLMs with histopathologic-demonstrated desmoplastic (n = 68) or replacement (n = 58) HGPs were assessed. The radiomics signature consisted of 20 features of each phase selected. The 3 phases fused radiomics signature demonstrated the best predictive performance in distinguishing between replacement and desmoplastic HGPs (AUCs of 0.926 and 0.939 in the training and external validation cohorts, respectively). The clinical-radiomics combined model showed good discrimination (C-indices of 0.941 and 0.833 in the training and external validation cohorts, respectively). A radiomics model derived from MDCT images may effectively predict the HGP of CRLMs, thus providing a basis for prognostic stratification and therapeutic decision-making.

How to assess a CTA of the abdomen to plan an autologous breast reconstruction.

The deep inferior epigastric perforator (DIEP) flap is recognised as the most popular option for autologous breast reconstruction. Planning of the DIEP flap involves pre-operative assessment of abdominal vascular anatomy with imaging, of which computed tomographic angiography (CTA) has become the mainstay. CTA enables detailed planning of a range of surgical steps, leading to reduced operative times and improved surgical outcomes. The value of CTA is only demonstrated when the relevant vascular anatomy is able to be demonstrated and appraised. For optimal analysis, a 64-slice multi-detector row CT scanner and imaging software including OsiriX™, Siemens InSpace™ or Horos™ are required. The seven major steps to consider include: (I) perforator size; (II) perforator angiosome; (III) intramuscular course; (IV) deep inferior epigastric artery (DIEA) pedicle; (V) venous anatomy; (VI) superficial inferior epigastric artery (SIEA) and superficial inferior epigastric vein (SIEV); and (VII) abdominal wall structure. These steps should also be reviewed when marking the patient and planning the flap intra-operatively. While CTA has superior sensitivity and specificity in mapping perforator anatomy it also faces challenges due to ionising radiation exposure, contrast-induced allergy and potential nephrotoxicity. Despite these challenges, the benefits of CTA to the individual patient has maintained its role in pre-operative planning of the DIEP flap.

ATYPICAL RADIOGRAPHIC PRESENTATION OF OSSIFYING FIBROMA

<h3>Background</h3> <i>History</i>: A 21-year-old female presented with a 1-year history of pain in the mandibular right premolar region. <i>Radiographic findings</i>: The multidetector computed tomography (MDCT) images showed a 5 × 1.7 cm radiolucent lesion of the mandible extending from the left canine, across the midline, to the right second molar. There was thinning of the buccal and lingual cortices, with displacement of the buccal cortex. There was evidence of thin trabeculae in the buccal cortical area. There was displacement of the first and second premolars in the region, with evidence of resorption of the roots of the incisors and right first and second molars. The inferior alveolar canal was not visualized within the region of the lesion, and it was difficult to determine if there was displacement or destruction of the canal. <i>Differential Interpretation</i>: The differential interpretation included giant cell lesion, ameloblastoma, odontogenic keratocyst, and odontogenic myxoma. <i>Microscopic Description</i>: Microscopic examination revealed multiple, small, round to ovoid islands of demineralized osteoid and acellular basophilic material, scattered amidst a dense fibrocollagenous connective tissue, populated with bland, occasionally stellate, fibroblasts. <h3>Discussion/Conclusions</h3> The lesion was diagnosed as benign fibro-osseous lesion consistent with a cemento-ossifying fibroma. The MDCT images provided a challenging interpretation in this case. On the basis of the images, the more obvious diagnosis was toward a benign cyst or tumor, such as a giant cell lesion, with differential diagnoses of ameloblastoma, odontogenic keratocyst, or odontogenic myxoma. However, we should not rule out aggressive ossifying fibromas among the differential diagnoses as this case clearly proves with such typical features.

Evaluation of the human petrotympanic fissure using anatomized cadaveric specimens and multi-detector CT imaging.

The purpose of the current study is twofold. First, to investigate the variability of the petrotympanic fissure's (PTF) morphology in anatomized human cadaveric specimens using multi-detector computed tomography (MDCT), and second, to compare the resulting measurements to investigate the possibilities of applying MDCT in the determination of PTF morphology in living humans. Specimens (n = 15) containing the temporal bone and TMJ were obtained from embalmed adult female (53.3%) and male (46.7%) cadavers and imaged using a helical 16-row scanner. Afterwards, cryosections were obtained and morphometric parameters were measured. Degree of agreement between both determinations was investigated and morphometric variables were also compared between PTF types. Three different types of PTF were identified. Type 1 was a wide tunnel-shaped structure. It was found in 20% of the cases. Type 2 was wide in the entrance but gradually narrows to the tympanic cavity. It was found in 46.7% of specimens. Finally, type 3, which was observed in 33.3% of the cases, was wide at the entrance of the mandibular fossa, followed by a middle region with flat-shaped tunnel structure and a narrow exit. The PTF's vertical diameters at the mandibular fossa, midpoint, and tympanic cavity and the width at the mandibular fossa all were significantly greater in type 1 specimens. MDCT is suitable for investigating the variable morphology of human PTF and its association with middle ear's and TMJ pathologies.

Adhesive and non-adhesive internal hernia: clinical relevance and multi-detector CT images

Internal hernia (IH)-related surgical acute abdomen is not well understood because of the rarity of cases and underdiagnosis. This study was performed to further understand the clinicopathological features and multi-detector computed tomography (MDCT) findings of IH in cases confirmed by surgery. In all, 51 patients with a definite diagnosis of IH confirmed during surgical exploration from Feb. 2012 to Feb. 2018 in our hospital were included in this research. Medical records, including MDCT images and intra-operative findings, were collected retrospectively. In all, 39 and 12 cases were categorized as adhesive IH (76.5%) and non-adhesive IH (23.5%), respectively. Among the patients with adhesive IH, 73% had a history of abdominal or pelvic surgery. Additionally, the mesentery was the most common component of adhesive bands (64.1%). Congenital peritoneal abnormalities and gastrointestinal reconstruction were the main causes of non-adhesive IH.As a specific sign, the fat notch sign was much more common in adhesive IH than in non-adhesive IH (P = 0.023). Bowel wall thickening (P = 0.041), abnormal bowel wall enhancement (P = 0.006) and twisted bowels with the vessel swirl sign (P = 0.004) were indicators of bowel necrosis. Among all of the cases of IH, 34 (66.7%) were complicated by bowel necrosis, and 1 patient died. In conclusion, non-adhesive IH has different clinicopathological features and MDCT findings from those of adhesive IH. MDCT is a useful tool with high sensitivity for confirming IH and may help to guide the early treatment of IH.

The preliminary study for three-dimensional alveolar bone morphologic characteristics for alveolar bone restoration

BackgroundThe concept of the ideal morphology for the alveolar bone form is an important element to reconstruct or restore the in maximizing esthetic profile and functional alveolar bone restoration. The purpose of this preliminary study is to evaluate the normal alveolar bone structure to provide the standard reference and guide template for use in diagnosing for implant placement, determining the correct amount of bone augmentation in actual clinical practice and producing prostheses based on three-dimensional imaging assessment of alveolar bone.MethodsThis study was included 11 men and 11 women (average age, 22.6 and 24.5 years, respectively) selected from among 127 patients. The horizontal widths of alveolar bone of maxilla and mandible were measured at the crestal, mid-root, and root apex level on MDCT (multi-detector computed tomography) images reconstructed by medical imaging software. In addition, tooth dimensions of the central incisors, canines, second premolars, and first molars of maxilla and mandible, including the horizontal width of the interdental alveolar bone crest, were also measured and statistically analyzed.ResultsThe horizontal alveolar bone width of the palatal side of maxilla showed a distinct increment from the alveolar bone crest to the apical region in both anterior and posterior areas. The average widths of the maxillary alveolar ridge were as follows: central incisor, 7.43 mm; canine, 8.91 mm; second premolar, 9.57 mm; and first molar, 12.38 mm. The average widths of the mandibular alveolar ridge were as follows: central incisor, 6.21 mm; canine, 8.55 mm; second premolar, 8.45 mm; and first molar, 10.02 mm. In the buccal side, the alveolar bone width was not increased from the crest to the apical region. The horizontal alveolar bone width of an apical and mandibular border region was thinner than at the mid-root level.ConclusionsThe results of the preliminary study are useful as a clinical guideline when determining dental implant diameter and position. And also, these measurements can also be useful during the production of prefabricated membranes and customized alveolar bone scaffolds.

Pulmonary Obstruction Index in Multidetector Computed Tomographic Imaging for the Risk Assessment of Right Ventricular Dysfunction in Patients with Pulmonary Embolism

Objectives: Rapid and accurate risk assessment is critical in selecting the appropriate treatment strategy in the management of pulmonary embolism. This study was designed to assess the relationship between multidetector computed tomographic (MDCT) imaging and the pulmonary obstruction index, right ventricular dysfunction, and serum D-dimer levels in normotensive patients with pulmonary embolism. Patients and Methods: In 74 patients with suspected pulmonary embolism (38 men, 36 women), two readers in consensus assessed the central clot score and the signs of right ventricular dysfunction using MDCT by quantifying right ventricular diameter (RVD), left ventricular diameter (LVD), the ratio of the right ventricle to left ventricle short-axis diameters (RV/LV), and septal deviation. Results: The patients were divided into three groups. Thirty five patients had negative CT pulmonary angiography (CTPA) and deep vein thrombosis (DVT) findings (group 1), 29 had positive CTPA and negative DVT findings of pulmonary embolism (PE) (group 2), and 10 patients had positive DVT and CTPA findings (group 3). Serum D-dimer levels were statistically higher in group 3 than in the other groups. It was found as 329.2 ± 46.9, 461.3 ± 70.5, and 1726.6 ± 543.5 in groups 1, 2, and 3 (P = 0.0001), respectively. We found a significant positive correlation between the lower extremity clot load score and the pulmonary artery obstruction index, and pulmonary artery clot volumes. The right ventricle (RV)/left ventricle (LV) short-axis ratio, azygos vein diameter, the RV wall thickness (RVW), reflux of contrast medium into the inferior vena cava (IVC), leftward septal bowing, and interventricular septal thickness were statistically different in group 1 compared to groups 2 and 3. Conclusion: Evaluation of the total pulmonary artery clot load and morphologic findings of the right heart obtained using CTPA are extremely important in order to follow up patients with suspected venous thrombosis.

Diagnostic performance of gadoxetic acid\u2013enhanced liver MRI versus multidetector CT in the assessment of colorectal liver metastases compared to hepatic resection

BackgroundImaging is an essential tool in the management of patients with Colorectal cancer (CRC) by helping evaluate number and sites of metastases, determine resectability, assess response to treatment, detect drug toxicities and recurrences. Although multidetector computed tomography (MDCT) is the first tool used for staging and patient’s surveillance, magnetic resonance imaging (MRI) is the most reliable imaging modality that allows to assess liver metastases. Our purpose is to compare the diagnostic performance of gadoxetic acid-(Gd-EOB) enhanced liver MRI and contrast-enhanced MDCT in the detection of liver metastasis from colorectal cancer (mCRC).MethodsOne hundred and twenty-eight patients with pathologically proven mCRC (512 liver metastases) underwent Gd-EOB MRI and MDCT imaging. An additional 46 patients without mCRC were included as control subjects. Three radiologists independently graded the presence of liver nodules on a five-point confidence scale. Sensitivity and specificity for the detection of metastases were calculated. Weighted к values were used to evaluate inter-reader agreement of the confidence scale regarding the presence of the lesion.ResultsMRI detected 489 liver metastases and MDCT 384. In terms of per-lesion sensitivity in the detection of liver metastasis, all three readers had higher diagnostic sensitivity with Gd-EOB MRI than with MDCT (95.5% vs. 72% reader 1; 90% vs. 72% reader 2; 96% vs. 75% reader 3). Each reader showed a statistical significant difference (p < <.001 at Chi square test). MR imaging showed a higher performance than MDCT in per-patient detection sensitivity (100% vs. 74.2% [p < <.001] reader 1, 98% vs. 73% [p < <.001] reader 2, and 100% vs. 78% [p < <.001] reader 3). In the control group, MRI and MDCT showed similar per-patient specificity (100% vs. 98% [p = 0.31] reader 1, 100% vs. 100% [p = 0.92] reader 2, and 100% vs. 96% [p = 0.047] reader 3). Inter-reader agreement of lesion detection between the three radiologists was moderate to excellent (k range, 0.56–0.86) for Gd-EOB MRI and substantial to excellent for MDCT (k range, 0.75–0.8).ConclusionGadoxetic acid-enhanced MRI performs significantly better in the detection of mCRC, than MDCT, particularly in patients treated with chemotherapy, in subcapsular lesions, and in peribiliary metastases.

Spectrum of multi-detector computed tomography imaging findings of thoracic vascular injuries secondary to blunt chest trauma: Correlation with vascular intervention and patient outcomes.

BackgroundThoracic vascular injuries following blunt chest trauma are the second leading cause of trauma-related deaths. Multi-detector computed tomography (MDCT) is the imaging modality of choice in detecting these injuries.ObjectivesTo determine the spectrum of vascular injuries detected on MDCT imaging in patients who sustained blunt chest trauma, and to assess the various types of management options and patient outcomes.MethodWe retrospectively reviewed archived medical records of polytrauma patients who presented with blunt chest trauma and confirmed vascular injury on MDCT and vascular intervention images between May 2015 and August 2018 at Inkosi Albert Luthuli Central Hospital.ResultsThirty-nine patients with vascular injury findings were analysed. The injury spectrum comprised: 15 aortic injuries (AI), 19 non-aortic injuries (NAI), 4 combined (AI and NAI) and 1 aorto-venous injury. A majority of males (69%) with an overall mean age of 39 years constituted the study cohort. The commonest injury mechanisms included motor vehicle collisions (61%) and pedestrian accidents (28%); the remaining 11% were shared amongst motorbike accidents or falling from a moving train or a height. The subclavian artery (36%) was the most common anatomical location in the NAI and the frequent imaging finding was vessel occlusion (55%). The most common imaging findings in AI were the indirect signs (20.5%) followed by a grade III injury (15.4%). Six patients with a grade III AI were successfully managed with endovascular repair.ConclusionA thorough knowledge of blunt vascular injury spectrums and imaging manifestations is critical when interpreting MDCT scans. Awareness of the mechanism of injury will trigger a high index of suspicion and probe a search for a vascular injury.

Deciphering normal and anomalous viscero-atrial situs on multidetector CT angiography.

Viscero-atrial situs encompasses the laterality, relative position and configuration of the abdominal viscera, the atria of the heart and the tracheobronchial tree. Determining the situs and cardiac position is the first step in the commonly used sequential, segmental approach to the imaging evaluation of congenital heart defects (CHD). Abnormalities of visceroatrial situs and cardiac position are frequently associated with the presence of complex CHDs and accurate assessment of situs abnormalities can help predict the probability and type of the defect. Multidetector CT (MDCT) angiography, with its multiplanar reformatting and volume rendering techniques, offers accurate information about the morphology and three-dimensional relationships of the various cardiac and extra cardiac structures. In this pictorial essay, we present the MDCT imaging findings of the spectrum of abnormalities of visceroatrial situs and cardiac position, using a third generation dual source CT scanner.

Clinical usefulness of conversion surgery for unresectable pancreatic cancer diagnosed on multidetector computed tomography imaging: Results from a multicenter observational cohort study by the Hokkaido Pancreatic Cancer Study Group (HOPS UR-01).

Background and AimEffective multidisciplinary approaches for unresectable pancreatic cancer (UR‐PC) that include modern chemotherapeutic regimens and subsequent conversion surgery (CS) are being developed. The aim of this study was to evaluate outcomes of patients clinically diagnosed with UR‐PC, focusing on the efficacy of CS.MethodsPatients ineligible for two multicenter phase II studies conducted by the Hokkaido Pancreatic Cancer Study Group (HOPS) were recruited. Sequential treatment regimens, conversion to radical surgery, and overall survival (OS) were analyzed by multidetector computed tomography (MDCT)‐based UR factors. Univariate and multivariate analyses were performed to identify predictors of OS.ResultsSixty‐six of 247 intended recruits for HOPS studies from October 2013 to April 2016 were included. Unresectability was due to locally advanced (LA) disease and metastasis (M) in 42 and 24 patients, respectively. Induction therapy began with chemotherapy (CT) and chemoradiotherapy (CRT) in 44 and 17 patients, respectively, of whom 23 received modern CT regimens. Radical surgery was completed in 12 (LA, 10; M, two) with a median treatment interval of 10.3 months (range, 2‐32). Eleven patients (91.6%) achieved pathological R0 resection. Median OS was significantly longer in patients who underwent CS than those who did not (44.1 vs 14.5 months, P < 0.0001). CS was an independent predictor of OS (hazard ratio, 0.078; 95% confident interval, 0.017‐0.348; P = 0.001).ConclusionConversion surgery after a favorable response to sequential treatment might prolong survival in patients with UR‐PC. Precise diagnosis on MDCT followed by sequential multimodal anticancer treatment is essential.