Multisection CT: scanning techniques and clinical applications

A comprehensive survey on the use of deep learning techniques in glioblastoma

Glioblastoma, characterized as a grade 4 astrocytoma, stands out as the most aggressive brain tumor, often leading to dire outcomes. The challenge of treating glioblastoma is exacerbated by the convergence of genetic mutations and disruptions in gene expression, driven by alterations in epigenetic mechanisms. The integration of artificial intelligence, inclusive of machine learning algorithms, has emerged as an indispensable asset in medical analyses. AI is becoming a necessary tool in medicine and beyond. Current research on Glioblastoma predominantly revolves around non-omics data modalities, prominently including magnetic resonance imaging, computed tomography, and positron emission tomography. Nonetheless, the assimilation of omic data-encompassing gene expression through transcriptomics and epigenomics-offers pivotal insights into patients' conditions. These insights, reciprocally, hold significant value in refining diagnoses, guiding decision- making processes, and devising efficacious treatment strategies. This survey's core objective encompasses a comprehensive exploration of noteworthy applications of machine learning methodologies in the domain of glioblastoma, alongside closely associated research pursuits. The study accentuates the deployment of artificial intelligence techniques for both non-omics and omics data, encompassing a range of tasks. Furthermore, the survey underscores the intricate challenges posed by the inherent heterogeneity of Glioblastoma, delving into strategies aimed at addressing its multifaceted nature.

CT Scan Data Analysis in Malformations of Cortical Development

Malformations of cortical development (MCDs) are a diverse group of disorders that result from abnormal neuronal migration, proliferation, and differentiation during brain development. Head computed tomography (CT) has limited use in the diagnosis of MCDs and should be reserved for selected cases with specific indications or when magnetic resonance imaging is not available or contraindicated. CT can detect brain calcifications associated with MCDs, thus helping in the differential diagnosis between acquired and genetic MCDs or in the identification of different genetic patterns. Moreover, CT can provide high-resolution images of the skull and bones, thus identifying associated malformations, such as craniosynostosis, inner and middle ear malformations, and vertebral anomalies. In this chapter, we review the CT scan technique, data analysis, and indications in the investigation of MCDs.

[Investigating the Usefulness of Breath-holding Instructions by Change in the Room Light for the Hearing Impaired]

PURPOSE

In imaging examinations of patients with hearing impairment, poor image quality due to poor respiratory arrest is a problem directly related to diagnostic imaging. Although there have been studies of non-sound instructions, there have been few quantitative studies using changes in brightness. The purpose of this study was to investigate whether changes in room brightness can be used as a respiratory cessation indicator.

METHODS

Fourteen patients were imaged using the 2D FIESTA and LAVA-Flex methods on an MRI system under free respiration, voice-guided cessation of respiration (voice instruction), and room brightness change (light/dark instruction), and compared.

RESULTS

The positional fluctuation of the top of the liver by the 2D FIESTA method showed a large positional fluctuation under free breathing, while the positional fluctuation was small under voice instruction and light/dark instruction. The images obtained by the LAVA-Flex method was significantly degraded by motion artifacts under free breathing, whereas there were fewer motion artifacts under voice instruction and light/dark instruction, and the two were the same with no significant difference in visual evaluation.

CONCLUSION

The visual cessation of respiration instruction by changing the brightness of the room is as effective as the audible cessation of respiration instruction, suggesting that it can be applied clinically.

Transfer learning framework for low-dose CT reconstruction based on marginal distribution adaptation in multiscale

BACKGROUND

With the increasing use of computed tomography (CT) in clinical practice, limiting CT radiation exposure to reduce potential cancer risks has become one of the important directions of medical imaging research. As the dose decreases, the reconstructed CT image will be severely degraded by projection noise.

PURPOSE

As an important method of image processing, supervised deep learning has been widely used in the restoration of low-dose CT (LDCT) in recent years. However, the normal-dose CT (NDCT) corresponding to a specific LDCT (it is regarded as the label of the LDCT, which is necessary for supervised learning) is very difficult to obtain so that the application of supervised learning methods in LDCT reconstruction is limited. It is necessary to construct a unsupervised deep learning framework for LDCT reconstruction that does not depend on paired LDCT-NDCT datasets.

METHODS

We presented an unsupervised learning framework for the transferring from the identity mapping to the low-dose reconstruction task, called marginal distribution adaptation in multiscale (MDAM). For NDCTs as source domain data, MDAM is an identity map with two parts: firstly, it establishes a dimensionality reduction mapping, which can obtain the same feature distribution from NDCTs and LDCTs; and then NDCTs is retrieved by reconstructing the image overview and details from the low-dimensional features. For the purpose of the feature transfer between source domain and target domain (LDCTs), we introduce the multiscale feature extraction in the MDAM, and then eliminate differences in probability distributions of these multiscale features between NDCTs and LDCTs through wavelet decomposition and domain adaptation learning.

RESULTS

Image quality evaluation metrics and subjective quality scores show that, as an unsupervised method, the performance of the MDAM approaches or even surpasses some state-of-the-art supervised methods. Especially, MDAM has been favorably evaluated in terms of noise suppression, structural preservation, and lesion detection.

CONCLUSIONS

We demonstrated that, the MDAM framework can reconstruct corresponding NDCTs from LDCTs with high accuracy, and without relying on any labeles. Moreover, it is more suitable for clinical application compared with supervised learning methods.

Enhancement of Anemia Detection by Correlating Computed Tomography Findings of Abdominal Aorta and Inferior Vena Cava With Laboratory Investigations

Anemia affects approximately a quarter of the global population, and improved detection may reduce the associated morbidity and mortality. This study investigated correlations between the results of laboratory hematological determinations of hemoglobin levels and attenuation values measured in the lumina of the abdominal aorta and inferior vena cava (IVC) via unenhanced computed tomography (CT) with the aim of expanding diagnostic options for anemia. The data of 423 patients who underwent abdominal unenhanced CT examinations and laboratory examinations at a tertiary hospital were retrospectively evaluated. CT data were collected using a standard abdominal protocol without contrast. The 151 patients who met the inclusion criteria were categorized by hemoglobin values as follows: <8 (severe anemia), 8-10.9 (moderate anemia), 10.9-12 (mild anemia in females), 10.9-13 (mild anemia in males), and >13 g/dL (non-anemic). The mean CT attenuation values in the aorta and IVC were 37.7 and 36.1 Hounsfield units (HU), respectively. A regression analysis performed to evaluate the correlation and predictability of hemoglobin-based aortic and IVC density yielded a coefficient of determination, R²: 0.42 (F ratio: 149.23, p < 0.0001). The highest contribution in the dependent variable (hemoglobin) was reported to IVC density, showing a significant positive correlation between hemoglobin and IVC density. Our study results demonstrate significant correlations between the densities of the aorta, IVC, and hemoglobin value. Accordingly, radiologists and clinicians can use these readily available values to facilitate diagnosis and patient care.

Association Between Hounsfield Units in Preoperative Wrist Computed Tomography Scans and Outcomes After Wrist Fracture Surgery

Purpose

This work aims to evaluate the hypothesis that the value of Hounsfield units (HU), as a marker of bone density, in preoperative wrist computed tomography (CT) scans correlates with the functional outcomes as measured by patient reported outcomes (PROs) after distal radius fracture surgery with volar locking plate fixation.

Methods

Of a database of 92 wrist fractures operated on in our hospital between 2011 and 2020, with a preoperative CT scan performed, we selected the cases with a minimum follow-up period of 12 months. After applying the exclusion criteria, the final cohort comprised 64 patients. Three measurements of HU were performed in correlative coronal sections of the capitate bone. PROs were determined using two functional questionnaires (DASH and PRWE) and one quality of life questionnaire (SF-12). The statistical relationship between PROs and the HU measurements obtained via a CT scan was analyzed.

Results

Patients were classified into two groups, osteoporotic (OST) or non-osteoporotic (non-OST), according to the optimal cut-off value of 323 HU selected using a ROC curve. The median DASH questionnaire score in the OST group was significantly higher (1.7 vs 10.0, p = 0.003).

Conclusion

HU values in preoperative wrist CT scans may help to identify osteoporotic bone in patients prior to wrist fracture surgery and lead to an improved surgical indication and treatment strategy.

Level of Evidence

Level of evidence: Prognostic III.

Early Postoperative CT Scan Provides Prognostic Data on Clinical Outcomes of Fresh Osteochondral Transplantation of the Knee

BACKGROUND

There is a lack of information regarding the ability of imaging studies to predict clinical outcomes after fresh osteochondral allograft (FOCA) transplantation of the knee.

PURPOSE

To determine the value of computed tomography (CT) scans to predict the clinical outcome of FOCA transplantation using the assessment computed tomography osteochondral allograft (ACTOCA) score.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

We prospectively collected data from all consecutive patients who underwent FOCA transplantation for osteochondral knee lesions at one institution between August 2017 and August 2019. All patients were followed up for a minimum of 2 years. CT scans performed 6 months after surgery were evaluated by a musculoskeletal radiologist using the ACTOCA scoring system. The radiologist was blinded to the patient's medical history. Clinical outcomes were assessed preoperatively and at 12 and 30 months postoperatively using the International Knee Documentation Committee (IKDC) score, the Kujala score, the Tegner activity scale, and the Western Ontario Meniscal Evaluation Tool (WOMET) score.

RESULTS

A total of 38 cases were included. The ACTOCA score at 6 months after surgery showed a statistically significant correlation with clinical results at 12 and 30 months. The correlation was better at 30 months, showing a high negative correlation with the IKDC score (-0.663) and a moderate negative correlation with the Kujala, WOMET, and Tegner scores (-0.593; -0.547, and -0.593, respectively) (P < .001).

CONCLUSION

A statistically significant correlation between the mean ACTOCA score on CT scans at 6 months and the clinical results measured by the IKDC, Kujala, WOMET, and Tegner scores at 30 months confirmed the predictive value of the ACTOCA score for use in clinical practice.

Description and Use of Three-Dimensional Numerical Phantoms of Cardiac Computed Tomography Images

The World Health Organization indicates the top cause of death is heart disease. These diseases can be detected using several imaging modalities, especially cardiac computed tomography (CT), whose images have imperfections associated with noise and certain artifacts. To minimize the impact of these imperfections on the quality of the CT images, several researchers have developed digital image processing techniques (DPIT) by which the quality is evaluated considering several metrics and databases (DB), both real and simulated. This article describes the processes that made it possible to generate and utilize six three-dimensional synthetic cardiac DBs or voxels-based numerical phantoms. An exhaustive analysis of the most relevant features of images of the left ventricle, belonging to a real CT DB of the human heart, was performed. These features are recreated in the synthetic DBs, generating a reference phantom or ground truth free of imperfections (DB1) and five phantoms, in which Poisson noise (DB2), stair-step artifact (DB3), streak artifact (DB4), both artifacts (DB5) and all imperfections (DB6) are incorporated. These DBs can be used to determine the performance of DPIT, aimed at decreasing the effect of these imperfections on the quality of cardiac images.

Pulmonary functional imaging (PFI): A historical review and perspective

PFI Pulmonary Functional Imaging (PFI) refers to visualization and measurement of ventilation, perfusion, gas flow and exchange as well as biomechanics. In this review, we will highlight the historical development of PFI, describing recent advances and listing the various techniques for PFI offered per modality. Challenges PFI is facing and requirements for PFI from a clinical point of view will be pointed out. Hereby the review is meant as an introduction to PFI.

High Pitch Helical CT Reconstruction

To avoid severe limited-view artifacts in reconstructed CT images, current multi-row detector CT (MDCT) scanners with a single x-ray source-detector assembly need to limit table translation speeds such that the pitch p (viz., normalized table translation distance per gantry rotation) is lower than 1.5. When , it remains an open question whether one can reconstruct clinically useful helical CT images without severe artifacts. In this work, we show that a synergistic use of advanced techniques in conventional helical filtered backprojection, compressed sensing, and more recent deep learning methods can be properly integrated to enable accurate reconstruction up to p=4 without significant artifacts for single source MDCT scans.

Recent Advances in Atherosclerotic Disease Screening Using Pervasive Healthcare

Atherosclerosis screening helps the medical model transform from therapeutic medicine to preventive medicine by assessing degree of atherosclerosis prior to the occurrence of fatal vascular events. Pervasive screening emphasizes atherosclerotic monitoring with easy access, quick process, and advanced computing. In this work, we introduced five cutting-edge pervasive technologies including imaging photoplethysmography (iPPG), laser Doppler, radio frequency (RF), thermal imaging (TI), optical fiber sensing and piezoelectric sensor. IPPG measures physiological parameters by using video images that record the subtle skin color changes consistent with cardiac-synchronous blood volume changes in subcutaneous arteries and capillaries. Laser Doppler obtained the information on blood flow by analyzing the spectral components of backscattered light from the illuminated tissues surface. RF is based on Doppler shift caused by the periodic movement of the chest wall induced by respiration and heartbeat. TI measures vital signs by detecting electromagnetic radiation emitted by blood flow. The working principle of optical fiber sensor is to detect the change of light properties caused by the interaction between the measured physiological parameter and the entering light. Piezoelectric sensors are based on the piezoelectric effect of dielectrics. All these pervasive technologies are noninvasive, mobile, and can detect physiological parameters related to atherosclerosis screening.

CT of the medial clavicular epiphysis for forensic age estimation: hands up?

Purpose

The aim of this study was to assess the impact of arm position in computed tomography (CT) of the clavicle performed for forensic age estimation on clavicular position, image noise, and radiation dose.

Methods and materials

Forty-seven CT scans of the medial clavicular epiphysis performed for forensic age estimation were conducted with either hands and arms held upwards (CT_HU, 28 persons) or positioned at the body (CT_HD, 19 persons). Presets were identical for both positions (70 mAs/140 kVp; Brilliance iCT, Philips). Each CT scan was reconstructed with an iterative algorithm (i-Dose 4) and evaluated at the middle of the sternoclavicular joint. Clavicular angle was measured on a.p. topograms in relation to a horizontal line. Quantitative image noise was measured in air at the level of medial clavicular epiphysis. Effective dose and scan length were recorded.

Results

Hands-up position compared with hands-down position resulted in a lower lateral body diameter (CT_HU 41.1 ± 3.6 cm vs. CT_HD 44.6 ± 3.1 cm; P = 0.03), a reduced quantitative image noise (CT_HU: 39.5 ± 9.2; CT_HD: 46.2 ± 8.3; P = 0.02), and lower CTDI_vol (5.1 ± 1.4 mGy vs. 6.7 ± 1.8 mGy; P = 0.001). Scan length was longer in patients examined with hands up (HU: 8.5 ± 3.4 cm; HD: 6.2 ± 2.1 cm; P = 0.006). Mean effective dose for CT_HU was 0.79 ± 0.32 mSv compared with 0.95 ± 0.38 mSv in CT_HD (P = 0.12). Clavicular angle was 17° ± 6° in patients with hands down and 32° ± 7° in patients with hands up (P < 0.001).

Conclusion

By elevated arm positioning, the image quality of clavicular CT scans can be improved while maintaining radiation dose compared with hands down. Clavicular position differs according to the hand position. Thus, positioning patients with elevated hands is advisable for forensic clavicular CT examinations, but multiplanar CT reconstructions should be adjusted to clavicular position and scan length should be reduced to a minimum.

Utility of fast non-local means (FNLM) filter for detection of pulmonary nodules in chest CT for pediatric patient

PURPOSE

This study was aimed to evaluate the utility based on imaging quality of the fast non-local means (FNLM) filter in diagnosing lung nodules in pediatric chest computed tomography (CT).

METHODS

We retrospectively reviewed the chest CT reconstructed with both filtered back projection (FBP) and iterative reconstruction (IR) in pediatric patients with metastatic lung nodules. After applying FNLM filter with six h values (0.0001, 0.001, 0.01, 0.1, 1, and 10) to the FBP images, eight sets of images including FBP, IR, and FNLM were analyzed. The image quality of the lung nodules was evaluated objectively for coefficient of variation (COV), contrast to noise ratio (CNR), and point spread function (PSF), and subjectively for noise, sharpness, artifacts, and diagnostic acceptability.

RESULTS

The COV was lowest in IR images and decreased according to increasing h values and highest with FBP images (P < 0.001). The CNR was highest with IR images, increased according to increasing h values and lowest with FBP images (P < 0.001). The PSF was lower only in FNLM filter with h value of 0.0001 or 0.001 than in IR images (P < 0.001). In subjective analysis, only images of FNLM filter with h value of 0.0001 or 0.001 rarely showed unacceptable quality and had comparable results with IR images. There were less artifacts in FNLM images with h value of 0.0001 compared with IR images (p < 0.001).

CONCLUSION

FNLM filter with h values of 0.0001 allows comparable image quality with less artifacts compared with IR in diagnosing metastatic lung nodules in pediatric chest CT.

Imaging of the Middle and Visceral Mediastinum

The visceral mediastinum contains important vascular and non-vascular structures including the heart, great vessels, lymph nodes, and portions of the esophagus and trachea. Multiple imaging modalities, including chest radiography, computed tomography, MR imaging, and nuclear medicine studies, can be used to detect, diagnose, and characterize masses in this compartment. Lymphadenopathy is the most common process involving the visceral mediastinum and can be seen with a wide variety of diseases. Less commonly seen entities include foregut duplication cysts, neoplasms and other lesions arising from the trachea and esophagus, paragangliomas as well as other mesenchymal tumors.

A new computed tomography scoring system to assess osteochondral allograft transplantation for the knee: inter-observer and intra-observer agreement

AIM OF THE STUDY

To describe a new semiquantitative computed tomography (CT) scoring system for multi-feature analysis of cartilage defect repair by osteochondral allografts for the knee and to assess its intra-observer and inter-observer variability.

METHOD

A semiquantitative assessment CT osteochondral allograft (ACTOCA) scoring system was designed based on fresh osteochondral allograft transplantations for the knee. The system includes five CT features: density relative to host bone, integration at the host-graft junction, surface percentage with a discernible cleft at the host-graft junction, cystic changes, and intra-articular fragments. Inter-observer variability was calculated by three observers blinded to the patient's medical history and treatment. Intra-observer variability was also determined.

RESULTS

Inter-observer agreement was moderate to substantial for all CT score components and intra-observer agreement was moderate to almost perfect for all CT score components (κ > 0.5, p < 0.05).

CONCLUSION

The ACTOCA score is a reliable tool to evaluate integration of osteochondral allograft transplantations. It provides an accurate evaluation of bone changes and may help to standardize CT scan reports following osteochondral allograft transplantation for the knee.

A new reference line for coronal head CT to align with MRI: development of a standardised approach

BACKGROUND AND PURPOSE

There are great variations in how different technologists create the different imaging planes that can make a precise comparison of computed tomography and magnetic resonance imaging difficult. We aimed to identify a reference line for the coronal images on a computed tomography topography parallel to the posterior borderline of the brainstem (PB), matching standard coronal magnetic resonance imaging planes.

METHODS

We retrospectively reviewed computed tomography topography images of 80 consecutive patients to determine a computed tomography plane to match the PB on magnetic resonance imaging. These included the tuberculum sella (TS)-anterior arch of the C1 vertebra (C1), TS-tip of dens axis (D), dorsum sellae (DS)-C1 and DS-D. We compared these methods of prescribing the coronal computed tomography plane to coronal magnetic resonance imaging planes by measuring the angles between TS-C1 and PB, TS-M and PB, DS-C1 and PB, DS-D and PB on midsagittal brain magnetic resonance images. Bland-Altman plots were created to assess intra-observer reliability.

RESULTS

The angles between the PB line and each topogram-determined line are as follows: TS-C1, 10.40° ± 4.86°; TS-D, 22.46° ± 5.23°; DS-C1, 3.01° ± 3.16°; and DS-D, 11.53° ± 4.10°. The mean angles between the DS-C1 and the PB lines were significantly smaller than the mean angle between any other line (DS-D, TS-C1, or TS-D, all P < 0.001). Intra-observer agreement regarding the angular position of the reformatted coronal images on the lateral scout image was excellent (intraclass correlation coefficient >0.900, P < 0.05).

CONCLUSIONS

The DS-C1 is almost parallel to the PB and easily identifiable on the lateral scout topography of brain computed tomography. Utilising the DS-C1 line as the baseline for brain computed tomography could allow better corroboration with coronal magnetic resonance imaging angulation.

Image-based state-of-the-art techniques for the identification and classification of brain diseases: a review

Detection and classification methods have a vital and important role in identifying brain diseases. Timely detection and classification of brain diseases enable an accurate identification and effective management of brain impairment. Brain disorders are commonly most spreadable diseases and the diagnosing process is time-consuming and highly expensive. There is an utmost need to develop effective and advantageous methods for brain diseases detection and characterization. Magnetic resonance imaging (MRI), computed tomography (CT), and other various brain imaging scans are used to identify different brain diseases and disorders. Brain imaging scans are the efficient tool to understand the anatomical changes in brain in fast and accurate manner. These different brain imaging scans used with segmentation techniques and along with machine learning and deep learning techniques give maximum accuracy and efficiency. This paper focuses on different conventional approaches, machine learning and deep learning techniques used for the detection, and classification of brain diseases and abnormalities. This paper also summarizes the research gap and problems in the existing techniques used for detection and classification of brain disorders. Comparison and evaluation of different machine learning and deep learning techniques in terms of efficiency and accuracy are also highlighted in this paper. Furthermore, different brain diseases like leukoariaosis, Alzheimer's, Parkinson's, and Wilson's disorder are studied in the scope of machine learning and deep learning techniques.

Computed Tomography (CT) Protocols Associated with Cardiac and Bone Single-Photon Emission Computed Tomography/CT (SPECT/CT) in Korea

PURPOSE

Single-photon emission computed tomography/computed tomography (SPECT/CT) is an advanced hybrid nuclear medicine technology that generates both functional and anatomical images in a single study. As utilization of SPECT/CT in Korea has been increasing, the purpose of this study was to survey its application of cardiac and skeletal SPECT/CT imaging for protocol optimization.

METHODS

We surveyed CT protocols established for cardiac and skeletal SPECT/CT. We searched the guidelines for the CT protocols for SPECT/CT and reviewed the literature recently published.

RESULTS

Among 36 hybrid SPECT scanners equipped with four or more multi-channel detector CTs (MDCTs), 18 scanners were used to perform cardiac studies at both very low current CT (30-80 mA; 11.1%) and ultra-low current CT (13-30 mA; 88.9%). Among the 33 canners, very low current (≤ 80 mA) CT or low current CT (80-130 mA) was used in 23.5%, and 41.8% for spine disorders, and in 36.4% or 30.3% for foot/ankle disorders, respectively. In the CT reconstructions, slice thickness of 5 mm for cardiac studies was most commonly used (94.4%); thinner slices (0.6-1.0 mm) for spine and foot/ankle studies were used in 24.2% and 45.5%, respectively. We also reviewed the international guidelines.

CONCLUSIONS

The results and current recommendations will be helpful for optimizing CT protocols for SPECT/CT. Optimization of SPECT/CT protocols will be required for generating the proper strategy for the specific lesions and clinical purpose.

Estimation of Absorbed Dose of the Thyroid Gland in Patients Undergoing 64-Slice Head Computed Tomography and Comparison the Results with ImPACT Software and Computed Tomography Scan Dose Index

Thyroid exposure to radiation in brain computed tomography (CT) scan is of great value since it is considered as a vital organ. This study aimed to investigate the absorbed dose of thyroid by various protocols of head CT in patients referring to 64-slice CT scan center and to compare the values with the calculated dose by imaging performance and assessment of CT (ImPACT) method. Also, the values of CT scan dose index (CTDI) were calculated with semiconductor detector. In this cross-sectional study, 120 outpatients including three groups of forty individuals over 40 years old referring to the hospital radiology centers in Tehran for head CT were chosen and 3 thermo-luminescence dosimeter (TLD-GR200) were applied on thyroid gland of each patient. For brain CT, Absorbed and effective doses of thyroid gland were calculated by ImPACT software. In addition, semiconductor detector in head CTDI phantom calculated CTDI for the applied protocols. Mean effective dose of thyroid gland in brain scan group was calculated by TLD and ImPACT software which showed no significant difference (P < 0.001). Mean effective dose of thyroid gland in unidirectional and bi-directional sinus scan by TLD and ImPACT software were different significantly (P < 0.001). Also, the differences between CTDI values shown by brain and sinus scan protocol with semiconductor detector and those CTDI were significant (P < 0.001). The calculated values of absorbed dose and effective doses of thyroid by TLD and ImPACT software were not significantly different. Mean effective dose calculated for thyroid gland in head scans by TLD and ImPACT was less than the annual permissive level for thyroid gland suggested by International Committee on Radiological Protection. In this study, calculated values of thyroid effective dose in brain scan with 64-slice scanner were less than the calculated values in a similar study.

How to CT scan human mummies: Theoretical considerations and examples of use

OBJECTIVE

The purpose of this study was to develop and provide recommendations for computed tomography (CT) examinations of human mummies.

MATERIALS AND METHODS

Based on theoretical considerations and examples, recommendations for use are provided for scanning and image reconstruction parameters. Four examples are presented to illustrate the effect of different CT parameters on image quality.

RESULTS

The use of appropriate scanning parameters (detector collimation, pitch factor, rotation time) is known to improve image quality; technical considerations favor using lower tube voltage and higher tube current values for the purposes of scanning of human mummies. The use of appropriate image reconstruction parameters (slice thickness, increment, field of view, reconstruction filters) are the basis for individual reconstructions for the purpose of evaluation, documentation, illustration and data storage.

CONCLUSIONS

Downsizing the field of view to the region of interest as done in the clinical radiological routine represents one major tool to improve image quality.

SIGNIFICANCE

The provided recommendations should improve CT image quality in mummy studies as well as the handling of image data for reconstructions and storage.

LIMITATIONS

The recommendations for CT scanning parameters and image reconstructions were written with relatively new generation CT scanners in mind. Only a few examples of use were chosen and image quality assessment was performed subjectively and not by quantitative measurements.

Comparative Study between Multi-slice Computed Tomographic Arthrography and Arthroscopy in the Evaluation of Rotator Cuff Tears

Objective  To compare the imaging findings of anatomical alterations using multi-slice computed tomographic arthrography in the evaluation of rotator cuff tears in the shoulder, correlating them with the arthroscopy (the gold standard diagnostic test) findings. Materials and Methods  A longitudinal, prospective, comparative study of diagnostic accuracy performed in the period between June 2016 and June 2017 in patients of both sexes, aged between 40 and 70 years, with shoulder rotator cuff tendon tears and therapeutic need to undergo shoulder arthroscopy. Patients with contraindication to magnetic resonance imaging were included. After multi-slice computed tomographic arthrography, all patients underwent arthroscopy. Results  To obtain the results, the following parameters were determined: sensitivity, specificity, accuracy, positive predictive value, negative predictive value, and Kappa coefficient, and contrast between the imaging method and arthroscopy. Conclusion  In the impossibility of performing magnetic resonance imaging (the gold standard imaging technique), multi-slice computed tomographic arthrography is an imaging examination capable of evaluating/diagnosing rotator cuff tears.

Dismantling the pathophysiology of asthma using imaging

Asthma remains an important disease worldwide, causing high burden to patients and healthcare systems and presenting a need for better management and ultimately prevention and cure. Asthma is a very heterogeneous condition, with many different pathophysiological processes. Better measurement of those pathophysiological processes are needed to better phenotype disease, and to go beyond the current, highly limited measurements that are currently used: spirometry and symptoms. Sophisticated three-dimensional lung imaging using computed tomography and ventilation imaging (single photon emission computed tomography and positron emission tomography) and magnetic resonance imaging and methods of lung imaging applicable to asthma research are now highly developed. The body of current evidence suggests that abnormalities in structure and ventilatory function measured by imaging are clinically relevant, given their associations with disease severity, exacerbation risk and airflow obstruction. Therefore, lung imaging is ready for more widespread use in clinical trials and to become part of routine clinical assessment of asthma.

Role of Multidetector Computed Tomography (CT) Virtual Hysteroscopy in the Evaluation of Abnormal Uterine Bleeding in Reproductive Age

Background

Abnormal uterine bleeding (AUB) may be acute or chronic and is defined as bleeding from the uterine corpus that is abnormal in regularity, volume, frequency, or duration and occurs in the absence of pregnancy. It is a widespread complaint in the primary care units. The prevalence of abnormal bleeding is up to 30% among women of reproductive age.

Objective

To assess the role of CT virtual hysteroscopy in the evaluation of the uterine cavity in cases with abnormal uterine bleeding in reproductive age.

Methods

Cross sectional study was performed at Obstetrics and Gynecology Department and Radiology Department, Zagazig University hospitals, Egypt, on 124 women with abnormal uterine bleeding in reproductive age, and their uterine cavity was evaluated by both row multidetector computed tomography (MDCT) scanner and Office hysteroscopy.

Results

Mean age of studied group was 28.54 ± 5.99 years, and virtual hysteroscopy showed sensitivity 91.1% and specificity 85.3% in detection of abnormalities within uterine cavity. It showed sensitivity 91.1% and specificity 85.3% in cases of endometrial polyps. It yielded 88.5 % sensitivity and 100 % specificity in cases with submucous fibroids, while it yielded only 57.9 % sensitivity and 82.9% specificity in cases of thick endometrium.

Conclusion

Virtual CT hysteroscopy is a good negative test in cases of abnormal uterine bleeding but has some limitations that decrease its sensitivity.

Digital and intelligent liver surgery in the new era: Prospects and dilemmas

Despite tremendous advances in traditional imaging technology over the past few decades, the intraoperative identification of lesions is still based on naked eye observation or pre-operative image evaluation. However, these two-dimensional image data cannot objectively reflect the complex anatomical structure of the liver and the detailed morphological features of the lesion, which directly limits the clinical application value of these imaging data in surgery in that it cannot improve the curative efficacy of surgery and the prognosis of the patient. This traditional mode of diagnosis and treatment has been changed by digital medical imaging technology in the new era with its significant function of accurate and efficient diagnosis of diseases, selection of reasonable treatment schemes, improvement of radical resection rate and reduction of surgical risk. In this paper, we reviewed the latest application of digital intelligent diagnosis and treatment technology related to liver surgery in the hope that it may help to achieve accurate treatment of liver surgery diseases.

Knowledge and Awareness of CT Radiation Dose and Risk Among Patients

The study aims to assess the level of patients’ awareness and knowledge regarding radiation and dosage along with the associated risks from computed tomography (CT) scan. This cross-sectional study used questionnaires, which were distributed to the diagnostic imaging departments of six large local hospitals in Jordan between September 2014 and March 2015. A total of 600 patients completed the questionnaire, out of which, 52.33% of respondents were female and 47.6% male. The findings show insignificant effects of gender on patient’s knowledge ( P = .596) and significant effect of employment and profession on positive scores ( P = .000). Similarly, no statistical differences were found between gender and correct answers ( P = .707). This cohort of patients demonstrated a lack of awareness and knowledge about the use of ionizing radiation for diagnostic imaging. Thus, there may exist a similar lack of information that will require imaging professionals to raise patients’ awareness and offer them the appropriate information.

Evaluation of Carotid Wall Thickness by using Computed Tomography and Semiautomated Ultrasonographic Software

Purpose

The increased thickness of the carotid artery is associated with the development of coronary and cerebrovascular events. In this study our purpose was to evaluate the carotid artery wall thickness (CAWT) by using multidetector-row computed tomography angiography (MDCTA) and the intima media thickness (IMT) by using semiautomated ultrasonography (SA-US) to evaluate the agreement between the two methods.

Methods

This is a retrospective study, and the institutional review board approval was obtained. Twenty-one patients (age range, 59–81 years) were analyzed with the use of a 16-detector row CT and a sonographic scanner. In total, 14 subjects had shown cerebral ischemic symptoms. The IMT was quantified by the use of specific semiautomated software (ImgTracer™, Global Biomedical Technologies, Roseville, CA) by four expert observers, and the CAWT was measured by use of the MDCTA. Data were compared with the Wilcoxon test for paired samples. Bland–Altman statistics was used to measure the agreement between MDCTA and SA-US. A p value < 0.05 was considered significant.

Results

Forty-two carotids were analyzed, and the CAWT ranged from 0.64 to 2.99 mm, with a mean value of 1.438 mm. By analyzing the Bland–Altman plots, we observed a good agreement between SA-US and correlation coefficient r were 0.9250 (95% confidence interval [CI] 0.864–0.959; p < 0.0001), 0.9265 (95% CI 0.866–0.961; p < 0.0001), 0.9466 (95% CI 0.902–0.971; p < 0.0001), and 0.8621 (95% CI: 0.756–0.924; p < 0.0001) for observer 1, observer 2, observer 3 and observer 4 respectively.

Conclusions

Data of this preliminary study by using SA-US and MDCTA demonstrated a good agreement between in the measurement of CAWT and IMT.

Subtle Lisfranc Injuries: A Topical Review and Modification of the Classification System

Lisfranc injuries are relatively uncommon. No specific incidence of subtle injuries has been reported; however, almost one-third are missed on initial review. These missed injuries are a common cause of litigation. Although seen in high-energy injuries with direct application of forces, they are also associated with lower-energy indirect mechanisms, often on the athletic field. This article provides a topical review of subtle Lisfranc disruptions, focusing on contemporary perspectives, and describes a modification to the most prevalent classification system. [Orthopedics. 2018; 41(2):e168-e175.].

Post-mortem computed tomography: Technical principles and recommended parameter settings for high-resolution imaging

Post-mortem computed tomography (PMCT) has become a standard procedure in many forensic institutes worldwide. However, the standard scan protocols offered by vendors are optimised for clinical radiology and its main considerations regarding computed tomography (CT), namely, radiation exposure and motion artefacts. Thus, these protocols aim at low-dose imaging and fast imaging techniques. However, these considerations are negligible in post-mortem imaging, which allows for significantly increased image quality. Therefore, the parameters have to be adjusted to achieve the best image quality. Several parameters affect the image quality differently and have to be weighed against each other to achieve the best image quality for different diagnostic interests. There are two main groups of parameters that are adjustable by the user: acquisition parameters and reconstruction parameters. Acquisition parameters have to be selected prior to scanning and affect the raw data composition. In contrast, reconstruction parameters affect the calculation of the slice stacks from the raw data. This article describes the CT principles from acquiring image data to post-processing and provides an overview of the significant parameters for increasing the image quality in PMCT. Based on the CT principles, the effects of these parameters on the contrast, noise, resolution and frequently occurring artefacts are described. This article provides a guide for the performance of PMCT in morgues, clinical facilities or private practices.

Does radiography still have a significant diagnostic role in evaluation of acute traumatic wrist injuries? A prospective comparative study

AIM

The aim of this study was to evaluate and compare the diagnostic role of radiography and multi-detector computed tomography (MDCT) in acute traumatic wrist injuries.

PATIENTS AND METHODS

One hundred sixty-eight patients with acute wrist trauma were enrolled in our study. All patients had submitted to radiography and MDCT within 24 h after wrist trauma. The diagnostic role of radiography and MDCT was evaluated and compared. The effective radiation dose of the two techniques was calculated.

RESULTS

One hundred four (61.9%) and 84 (50%) out of 168 patients had acute wrist injuries on MDCT and radiographic examinations, respectively. Using MDCT results as a reference standard, the sensitivity, specificity, and accuracy of radiography in the diagnosis of distal radius fracture were 85.7, 96, and 92.3%, respectively, and in the diagnosis of scaphoid fracture were 62.5, 97.3, and 88.5%, respectively. As regards detection of acute traumatic wrist injuries, we observed no significant difference between the two modalities (P = 0.1347); in addition, both modalities had high consistency (κ = 0.8359). The mean effective radiation dose of radiography was 0.01 mSv and of MDCT was 0.1 mSv.

CONCLUSION

Radiography still remains as the first screening tool in acute traumatic wrist injuries and MDCT is complementary to it and used as a problem-solving tool or for preoperative planning.

Brain Computed Tomography Compared with Facial 3-Dimensional Computed Tomography for Diagnosis of Facial Fractures

OBJECTIVES

To compare the detection of facial fractures and radiation dose between brain computed tomography (CT) and facial 3-dimensional (3D) CT in pediatric patients who have experienced a trauma.

STUDY DESIGN

Four hundred pediatric patients who experienced a trauma and underwent immediate brain CT and facial 3D CT between January 2016 and June 2016 were included in this retrospective study. Two reviewers independently analyzed and determined the presence of the facial fractures of 8 anatomic regions based on brain CT and facial 3D CT over a 1-week interval. Suggested treatment decisions for facial fractures seen on brain CT and facial 3D CT were evaluated by one physician. The facial 3D CT scans, interpreted by a senior radiologist, were considered as the reference standard. Diagnostic performance, radiation dose, and interobserver agreement of the CT scans were evaluated.

RESULTS

Brain CT showed a high sensitivity (94.1%-96.5%), high specificity (99.7%-100%), and high accuracy (98.8%-99.0%) in both reviewers, and performed as well as did facial 3D CT (P ≥ .25). The suggested treatment decision was not different between the brain CT and facial 3D CT findings. The agreements between the reference standard and the reviewers, and between reviewers 1 and 2 were excellent (k = 0.946-0.993). The mean effective radiation doses used in brain CT (3.6 mSv) were significantly lower than those in brain CT with facial 3D CT (5.5 mSv) (P < .001).

CONCLUSIONS

Brain CT showed acceptable diagnostic performance and can be used as the first-line imaging tool in the workup of pediatric patients with suspected facial fractures.

Myocardial CT perfusion imaging for ischemia detection

Coronary computed tomography angiography (CCTA) plays an important role in many specific scenarios such as in symptomatic patients with intermediate pretest of coronary artery disease (CAD), as well as in the triage of patients with acute chest pain with TIMI risk ≤2. However, it cannot detect the presence of associated ischemia, which is critical for clinical decision making among patients with moderate to severe stenosis. Although functional information can be obtained with different non-invasive tools, cardiac CT is the unique modality that can perform a comprehensive evaluation of coronary anatomy plus the functional significance of lesions. Myocardial CT perfusion (CTP) can be performed with different approaches such as static and dynamic CTP. In addition, static CTP can be performed using single energy CT (SECT) or dual energy CT (DECT). In this review, we will discuss the technical parameters and the available clinical evidence of static CTP using both SECT and DECT.

4D-CT angiography with arterial- and venous-phase anatomical pre-surgical approaches in cases with head and neck neoplasms

PURPOSE

The relationship between neoplasm and its surrounding vascular structure is essential to the following clinical treatment plan. In this study, 4D computed tomography angiography (4D-CTA) with a wide scan range and dynamic phases of arteriography and venography was used to describe detailed anatomical information for pre-surgical approaches.

MATERIALS AND METHODS

From January 2011 to February 2012, we subjected 13 patients with head and neck neoplasms to 4D-CTA. 4D-CTA was performed by a multidetector computed tomography (MDCT) scanner of 320 detectors. The parameters were set to a 0.5 mm section thickness, at 0.5 second per rotation, 80 kV and 150 mA. The scan range was set depending on the tumor size, with a maximal setting of 16 cm. A 30 mL contrast medium with 60 mL saline was injected at the rate of 5-7 mL per second based on the vascular patency, scanning every 2 seconds from the 16th to the 28th second after contrast injection.

RESULTS

The vasculature surrounding the tumors was successfully illustrated in all cases. The 4D-CTA provided detailed vascular information that was compatible with the surgical and angiographic findings.

CONCLUSION

4D-CTA with a wide scan range and precise injection timing methods facilitated an anatomical approach to tumor-related vascular structures, providing detailed vascular information. This non-invasive technique may be useful for evaluating neoplasms and developing treatment plans, as an alternative to conventional angiography.

CT of facial fracture fixation: an experimental study of artefact reducing methods

OBJECTIVES

This study aimed to determine the optimal post-operative CT imaging method that enables best visualization of facial bony structures in the vicinity of osteosynthesis material.

METHODS

Conducted at Töölö Hospital (Helsinki, Finland), this study relied on scanning a phantom with CBCT, 64-slice CT and high-definition multislice CT with dual-energy scan (providing monochromatic images of 70-, 100-, 120- and 140-keV energy levels) and iterative reconstruction (IR) methods. Two radiologists assessed the image quality, and the assessments were analyzed. In addition, a physicist performed a semi-quantitative analysis of the metal-induced artefacts.

RESULTS

The three subjects most easily assessed were the loose screw and both the bone structure and the fracture further away from the screw and the plate. Soft tissues adjacent to the screw and the plate remained more difficult for assessment. Both image interpreters agreed that the artefacts disturbed their assessments under dual energy. Metal artefacts disturbed the least under multislice CT with IR [adaptive statistical iterative reconstruction (ASiR) and VEO]. Neither interpreter found metal suppression helpful in CBCT.

CONCLUSIONS

CBCT with or without a metal artefact reduction algorithm was not optimal for post-operative facial imaging compared with multislice CT with IR. Multislice CT with ASiR filtering offered good image quality performance with fast image volume reconstruction, representing the current sweet spot in post-operative maxillofacial imaging.

Magnetic hyperthermia controlled drug release in the GI tract: solving the problem of detection

Drug delivery to the gastrointestinal (GI) tract is highly challenging due to the harsh environments any drug- delivery vehicle must experience before it releases it's drug payload. Effective targeted drug delivery systems often rely on external stimuli to effect release, therefore knowing the exact location of the capsule and when to apply an external stimulus is paramount. We present a drug delivery system for the GI tract based on coating standard gelatin drug capsules with a model eicosane- superparamagnetic iron oxide nanoparticle composite coating, which is activated using magnetic hyperthermia as an on-demand release mechanism to heat and melt the coating. We also show that the capsules can be readily detected via rapid X-ray computed tomography (CT) and magnetic resonance imaging (MRI), vital for progressing such a system towards clinical applications. This also offers the opportunity to image the dispersion of the drug payload post release. These imaging techniques also influenced capsule content and design and the delivered dosage form. The ability to easily change design demonstrates the versatility of this system, a vital advantage for modern, patient-specific medicine.

In Vivo Estimates of the Position of Advanced Bionics Electrode Arrays in the Human Cochlea

Objectives:

A new technique for determining the position of each electrode in the cochlea is described and applied to spiral computed tomography data from 15 patients implanted with Advanced Bionics HiFocus I, Ij, or Helix arrays.

Methods:

ANALYZE imaging software was used to register 3-dimensional image volumes from patients' preoperative and postoperative scans and from a single body donor whose unimplanted ears were scanned clinically, with micro computed tomography and with orthogonal-plane fluorescence optical sectioning (OPFOS) microscopy. By use of this registration, we compared the atlas of OPFOS images of soft tissue within the body donor's cochlea with the bone and fluid/tissue boundary available in patient scan data to choose the midmodiolar axis position and judge the electrode position in the scala tympani or scala vestibuli, including the distance to the medial and lateral scalar walls. The angular rotation 0° start point is a line joining the midmodiolar axis and the middle of the cochlear canal entry from the vestibule.

Results:

The group mean array insertion depth was 477° (range, 286° to 655°). The word scores were negatively correlated (r = −0.59; p = .028) with the number of electrodes in the scala vestibuli.

Conclusions:

Although the individual variability in all measures was large, repeated patterns of suboptimal electrode placement were observed across subjects, underscoring the applicability of this technique.

In Vivo Estimates of the Position of Advanced Bionics Electrode Arrays in the Human Cochlea

Objectives:

A new technique for determining the position of each electrode in the cochlea is described and applied to spiral computed tomography data from 15 patients implanted with Advanced Bionics HiFocus I, Ij, or Helix arrays.

Methods:

ANALYZE imaging software was used to register 3-dimensional image volumes from patients' preoperative and postoperative scans and from a single body donor whose unimplanted ears were scanned clinically, with micro computed tomography and with orthogonal-plane fluorescence optical sectioning (OPFOS) microscopy. By use of this registration, we compared the atlas of OPFOS images of soft tissue within the body donor's cochlea with the bone and fluid/ tissue boundary available in patient scan data to choose the midmodiolar axis position and judge the electrode position in the scala tympani or scala vestibuli, including the distance to the medial and lateral scalar walls. The angular rotation 0° start point is a line joining the midmodiolar axis and the middle of the cochlear canal entry from the vestibule.

Results:

The group mean array insertion depth was 477° (range, 286° to 655°). The word scores were negatively correlated (r = −0.59; p = .028) with the number of electrodes in the scala vestibuli.

Conclusions:

Although the individual variability in all measures was large, repeated patterns of suboptimal electrode placement were observed across subjects, underscoring the applicability of this technique.

The Evolving Role of Medical Imaging in Lymphoma Management: The Clinician's Perspective

Hodgkin and non-Hodgkin lymphomas are a heterogeneous group of hematologic neoplasms which arise from malignant lymphocytes. Imaging plays an important role in management of lymphoma patients during diagnosis, staging, and response assessment. Functional imaging may also provide prognostic information and improve the ability to detect extranodal disease. This article provides an overview of the evolving role of various imaging techniques in lymphoma from the clinician's perspective. It serves as an introduction to the other articles in this issue that focus on specific areas of lymphoma imaging.

Multi-detector computed tomography imaging of large airway pathology: A pictorial review

The tracheobronchial tree is a musculo-cartilagenous framework which acts as a conduit to aerate the lungs and consequently the entire body. A large spectrum of pathological conditions can involve the trachea and bronchial airways. These may be congenital anomalies, infections, post-intubation airway injuries, foreign body aspiration or neoplasms involving the airway. Appropriate management of airway disease requires an early and accurate diagnosis. In this pictorial essay review, we will comprehensively describe the various airway pathologies and their imaging findings by multi-detector computed tomography.

Staging of colorectal cancer using contrast-enhanced multidetector computed tomographic colonography

INTRODUCTION

Preoperative staging is essential for the optimal treatment and surgical planning of colorectal cancers. This study was aimed to evaluate the accuracy of colorectal cancer staging done using contrast-enhanced multidetector computed tomographic colonography (CEMDCTC).

METHODS

We recruited 25 patients with 28 proven colorectal cancers. A 16-slice multidetector computed tomography scanner was used to generate two-dimensional multiplanar reformatted sagittal, coronal and oblique coronal images, and three-dimensional virtual colonography (endoluminal) images. Axial and reformatted views were analysed, and TNM staging was done. Patients underwent surgery and conventional colonoscopy, and surgical histopathological correlation was obtained.

RESULTS

The diagnostic accuracies for TNM colorectal cancer staging were 92.3% for T staging, 42.3% for N staging and 96.1% for M staging using CEMDCTC. There was excellent positive correlation for T staging between CEMDCTC and both surgery (κ-value = 0.686) and histopathology (κ-value = 0.838) (p < 0.0001), and moderate positive correlation for N staging between CEMDCTC and surgery (κ-value = 0.424; p < 0.0001). The correlation between CEMDCTC and histopathology for N staging was poor (κ-value = 0.186; p < 0.05); the negative predictive value was 100% for lymph node detection. Moderate positive correlation was seen for M staging between CEMDCTC and both surgery (κ-value = 0.462) and histopathology (κ-value = 0.649). No false negatives were identified in any of the M0 cases.

CONCLUSION

CEMDCTC correlated well with pathologic T and M stages, but poorly with pathologic N stage. It is an extremely accurate tool for T staging, but cannot reliably distinguish between malignant lymph nodes and enlarged reactive lymph nodes.

Comparison of emergency cranial CT interpretation between radiology residents and neuroradiologists: transverse versus three-dimensional images

PURPOSE

Three-dimensional (3D) reformatted images provide a more inclusive representation of abnormalities than transverse images in cranial computed tomography (CT). The purpose of this study was to assess the value of 3D reformations for radiology residents in the interpretation of emergency cranial CTs.

MATERIALS AND METHODS

In total, 218 consecutive patients who underwent emergency cranial CT scans with 3D reformation were included in this retrospective study. Four blinded readers (three radiology residents and a neuroradiologist) interpreted the transverse and 3D images in two separate sessions. Each reader assessed 1) abnormal finding(s) and the confidence score(s) (5-point scale) for transverse and 3D images, 2) added value score of 3D images (5-point scale), and 3) interpretation time for both transverse and 3D images. We analyzed discordance between each radiology resident and the neuroradiologist on a lesion-by-lesion basis.

RESULTS

In total, 509 lesions were detected in 218 patients. Discordance rates between the three residents and the neuroradiologist were 11.4%-20.2% (mean, 15.0%) and 8.8%-16.9% (mean, 12.1%) in the interpretation of transverse and 3D images, respectively. Confidence scores were higher for 3D images than for transverse images for all readers. The added value scores for the 3D images were relatively higher for the inexperienced residents. Interpretation times for 3D images were significantly higher than for transverse images for all readers.

CONCLUSION

The 3D reformations assist radiology residents in the interpretation of emergency cranial CT examinations.

Copper oxide nanoparticles as contrast agents for MRI and ultrasound dual-modality imaging

Multimodal medical imaging is gaining increased popularity in the clinic. This stems from the fact that data acquired from different physical phenomena may provide complementary information resulting in a more comprehensive picture of the pathological state. In this context, nano-sized contrast agents may augment the potential sensitivity of each imaging modality and allow targeted visualization of physiological points of interest (e.g. tumours). In this study, 7 nm copper oxide nanoparticles (CuO NPs) were synthesized and characterized. Then, in vitro and phantom specimens containing CuO NPs ranging from 2.4 to 320 μg · mL(-1) were scanned, using both 9.4 T MRI and through-transmission ultrasonic imaging. The results show that the CuO NPs induce shortening of the magnetic T1 relaxation time on the one hand, and increase the speed of sound and ultrasonic attenuation coefficient on the other. Moreover, these visible changes are NP concentration-dependent. The change in the physical properties resulted in a substantial increase in the contrast-to-noise ratio (3.4-6.8 in ultrasound and 1.2-19.3 in MRI). In conclusion, CuO NPs are excellent candidates for MRI-ultrasound dual imaging contrast agents. They offer radiation-free high spatial resolution scans by MRI, and cost-effective high temporal resolution scans by ultrasound.

MDCT Evaluation of Costal Bone Lesions: Comparison of Axial, Multiplanar, and 3D Volume-Rendered Images: A Retrospective Study

The aim of this retrospective study was to compare accuracies of axial, multiplanar, and volume-rendered 3-dimensional (3D) images in the diagnosis of costal bone lesions.Forty-one patients, aged from 10 to 72-years old, with costal bone lesions underwent multidetector CT (MDCT). Axial, multiplanar, and 3D-volume-rendered images were reviewed by 3 reviewers for the property of the lesions (fracture, tumor, and tumor-like lesions or inflammation). In case of fracture, the diagnosis was demonstrated with the location of the fracture and the amounts of the costal bone involved. In case of a tumor or tumor-like lesions, the diagnosis was demonstrated pathological property. Final diagnosis was determined by biopsy or surgery. Diagnostic accuracy and interreviewers agreement were evaluated.For the diagnosis of fractures, average accuracy was 77%, 100%, and 100% for axial, multiplanar, and 3D-volume-rendered images, respectively. For the diagnosis of tumor and tumor-like lesions, average accuracy was 90% for axial, 96% for multiplanar, and 99% for 3D-volume-rendered images. For the diagnosis of inflammation lesions, average accuracy was 100% for all the 3 image formats. Interobserver agreement independence of imaging formats was high.Multiplanar and 3D-volume-rendered images were superior to axial images in diagnosis of fracture, tumor, and tumor-like lesions; however, for the evaluation of inflammation lesions, there were no difference by 3 image formats.

The usefulness of combined axial and coronal computed tomography for the evaluation of metastatic supraclavicular lymph nodes

The purpose is to assess the value of adding coronal images for the identification of metastatic supraclavicular lymph nodes (LNs). Two radiologists reviewed axial images and combined axial and coronal images using thoracic computed tomography (CT) of 386 patients whose maximum standardized uptake value measured in a supraclavicular LN was ≥2.0 on a positron emission tomography. We compared sensitivity and agreement between readers before and after the addition of coronal images. For combined images, agreement was almost perfect (κ=0.982), and sensitivity was significantly higher (90.4%, P<.001). Interpreting both axial and coronal images improves the diagnostic accuracy for supraclavicular metastasis.