Multidetector Row CT Scanner Research Articles

The Efficiency of Volumetry in Graft Weight Assessment in Living Donor Liver Transplant

Abstract Background Liver transplantation is the treatment of choice for end-stage hepatic diseases. The most important factor responsible for the success of the transplant is the size of the graft and the remnant liver volume in the donor. A small graft may not meet the metabolic demands of the recipient resulting in impaired liver functions such as hyperbilirubinemia, prolonged prothrombin time (PT), ascites and portal hypertension. Patient and Methods This comparative study was conducted on manual contrast enhanced hepatic CT scans of 40 potential living liver donors (29) male and (11) female Age range from (18 to 50 ) in Ain shams specialized hospital and some private centers during the period from May 2021 till July 2022. The potential donors were investigated using 16 channel multi-detector row CT scanner (Alexion; Toshiba medical systems). All potential donors underwent 1st step laboratory investigations to enter the 2nd step investigations for living donor liver transplantation operations. All potential donors were of average weight and physically fit for operation with no history of any medical diseases. Results We correlated the results of CT volumetry of right lobe graft weight with the intra-operative weight of liver graft in patients undergoing Living Donor Liver Transplantation(LDLT). CT Volumetry is an efficient and a reliable tool for assessing potential donors undergoing liver transplant, and this information is essential for donor selection and pre operative surgical planning as well as it ensure that the liver remnant volume is at least 30 % which guarantee the safety of the donor. Conclusion The size of the right lobe graft for LDLT can be precisely calculated from pre-operative CT Volumetry with confidence and accuracy up to 95%.

Assessing the Diagnostic Role of Multidetector Computed Tomography in Bronchogenic Carcinoma: Histopathological Correlation and Clinical Insights

Background: Lung cancer is a global health issue, and Multi Detector Row Computed Tomography (MDCT) plays a crucial role in diagnosing and staging bronchogenic carcinoma. Purpose: To document bronchogenic carcinoma’s MDCT features and assess CT scan accuracy compared to histopathological diagnosis. Materials and Methods: Between June 2020 and November 2021, 70 patients with suspected bronchogenic carcinoma underwent clinical assessment and 128-slice MDCT scans from lung apices to upper abdomen, including adrenal glands. MDCT findings were compared to histopathological examination. Statistical analysis using SPSS 16 and Excel determined CT’s positive predictive value against histopathological diagnosis as the reference standard. Results: Out of the 70 patients, 41% were female, and 59% were male. Among those with suspected bronchogenic carcinoma in CT, 86% were confirmed as malignant through histological analysis. The mean age of patients with bronchogenic carcinoma was 61.5 years. Squamous cell carcinoma (43%) was the most common histological subtype, followed by adenocarcinoma (38%). There was a notable male predominance (68%) for bronchogenic carcinoma, with distinct patterns observed for different histological subtypes. MDCT exhibited an 86% positive predictive value in diagnosing bronchogenic carcinoma compared to histopathology. Conclusion: Squamous cell carcinoma emerged as the most prevalent subtype of bronchogenic carcinoma, with MDCT demonstrating high diagnostic accuracy. The study advocates for routine MDCT utilization in the diagnosis and staging of bronchogenic carcinoma. Consider limitations like absent interobserver variation and challenges in distinguishing reactive hyperplasia from metastatic lymphadenopathy. Future research could explore potential implications and applications of the study’s findings.

Study of the Intersegmental Veins Between S5 and S8 Based on 3D Reconstruction

BackgroundAnatomic resection (AR) is a surgical method for treating hepatocellular carcinoma, and identifying intersegmental planes between segments 5 (S5) and 8 (S8) remains challenging. This study aims to find reliable intersegmental veins (IVs) between them as anatomical landmarks using 3D reconstruction analysis. MethodsWe retrospectively evaluated 57 patients who underwent multidetector-row CT scans from September 2021 to January 2023. The portal vein watershed of S5 and S8 and hepatic veins were reconstructed using 3D reconstruction analysis software. We counted and analyzed the IVs running within the intersegmental plane between S5 and S8, examined their features, and analyzed the location of the junctions between IVs and middle hepatic veins (MHVs). ResultsAmong the 57 patients, 43 patients (75.4%) had IVs between S5 and S8. Most patients (81.4%) had a single IV joining the MHV, while 13.9% had two IVs, one joining the MHV and the other joining the right hepatic vein (RHV). The majority of IV-MHV junctions were found in the lower part of the MHVs. The most clearly identifiable junctions between the IVs and MHVs occurred slightly below the midpoint of the horizontal planes of the second hepatic portal and the center of the gallbladder bed. ConclusionOur study identified IVs between S5 and S8 in the liver as potential anatomical landmarks during AR for hepatocellular carcinoma surgery. We found three types of IVs and provided insights on how to locate their junctions with MHVs for easier surgical navigation. However, individual anatomical variations must be considered, and preoperative 3D reconstruction and personalized surgical planning are crucial for success. More research with larger sample sizes is needed to validate our findings and establish the clinical significance of these IVs as landmarks for AR.

Number of computed tomography scanners and regional disparities based on population and medical resources in Japan.

This study aimed to discover the associations between the number of computed tomography (CT) scanners and the population, as well as number of medical resources to identify regional disparities in Japan. The number of CT scanners was tabulated for each detector row of CT scanners for hospitals and clinics in each prefecture. The number of CT scanners, patients, medical doctors, radiological technologists, facilities, and beds per 100,000 population was compared. Additionally, the number of hospitals with ≥ 200 beds and multidetector-row CT scanners with ≥ 64 rows were tabulated, and their ratios were calculated. Medical institutions in Japan have installed 14,595 scanners. CT scanners per 100,000 population were the highest in Kochi Prefecture, although the number of CT scanners in hospitals was the highest in Tokyo Prefecture. Multivariate analysis revealed the number of radiological technologists (β coefficient: 0.49; P = 0.03), facilities (β coefficient: 0.12; P < 0.01) and beds (β coefficient: 0.46; P < 0.01) as independent factors for the number of CT scanners. Prefectures with a high proportion of hospitals with ≥ 200 beds also had a relatively high proportion of CT scanners with ≥ 64 rows (P < 0.01). Our survey revealed an association between regional disparities in the number of CT scanners in Japan, the population, and number of medical resources. A positive correlation was found between hospital size and number of CT scanners with ≥ 64 rows.

Gumbel distribution-based technique enables quantitative comparison between streak metal artifacts of multidetector row CT and cone-beam CT: a phantom study

Cone-beam computed tomography (CBCT), derived from multidetector row CT (MDCT), has a high spatial resolution and has recently been applied to various organs. One of the severe limitations common to CBCT and MDCT is metal artifacts. In particular, streak metal artifacts (SMAs) between multiple metal materials often hinder diagnosis. However, no studies have quantitatively compared the strength of SMAs in MDCT and CBCT. Nomura et al. reported an evaluation method specialized in SMAs of CBCT using the Gumbel distribution (GD), which can also be applied to SMAs of MDCT (Oral Surg Oral Med Oral Pathol Oral Radiol 131: 494-502,2021, https://doi.org/10.1016/J.OOOO.2020.08.031 ). This study aimed to quantitatively compare SMAs occurring between titanium materials on MDCT and CBCT images using the GD-based method. The SMAs were investigated as follows: A hydroxyapatite block was sandwiched between two titanium rods to generate an SMA. They were placed in an acrylic phantom, simulating a human head, and scanned using an MDCT scanner and two CBCT scanners. The obtained images were analyzed using Gumbel plots and location parameters, and the SMA strength was calculated. The results showed that the SMAs on the MDCT images were significantly weaker than those on the CBCT images. In the CBCT scans, a smaller volume CT dose indexvalue caused stronger SMAs. These results indicate that MDCT is more advantageous than CBCT in terms of SMA reduction when bone morphology between titanium materials must be evaluated. The characteristic should be considered in clinical cases.

Diagnostic accuracy and safety of CT-guided Lung and Mediastinal biopsies: a single center study

Background: Computed tomography (CT)-guided percutaneous needle biopsy plays a critical role in establishing tissue diagnosis of malignancy, guiding staging, and planning treatment for pulmonary abnormalities. Aim: To determine diagnostic accuracy and incidence of complications occurring after taking percutaneous CT-guided lung biopsy. Methodology: In this retrospective study, we evaluated 44 CT-guided chest biopsies (31 lung biopsies and 13 mediastinal biopsies) performed at our institution between September 2019 and March 2022. A coaxial core biopsy needle technique was used for all CT-guided biopsies. All procedures were performed by an experienced consultant interventional radiologist using using a commercially available helical multidetector-row CT scanner. Results: There were 29 men and 15 women among the 44 patients, ranging in age from 25 to 65 years. We found technical accuracy (described as tip of core biopsy needle within centre of lesion) of 100% (44/44) and diagnostic accuracy (described as adequate sample for histological assessment) of 97.7% (43/44) in our study. The overall incidence of complications during the procedure were recorded including pneumothorax (n = 2, 4.5%),pulmonary hemorrhage (n = 1, 2.3%), hemoptysis (n = 1, 2.3%). Conclusion: CT-guided chest biopsy is a safe procedure and has good diagnostic accuracy. However, radiologists approaching such interventional procedures must be experienced and well trained so that there are less chances of developing complications after the procedure. Practical implications: We suggest physicians performing chest biopsies to adopt better techniques and use shortest path to the lesion during needle insertion. Although CT-guided chest biopsy has fewer chances of complications, however, interventional radiologists should be conscious of potential complications. Keywords: CT-guided biopsy; Percutaneous biopsy; Imaging, Interventional radiology; Diagnosis.

Evaluation of Preoperative Multidetector Row Computed Tomography in Colon Malignancy with Reference to (Local Staging and Lymph Node Status)

A proper preliminary stage is essential for determining the appropriate therapy approach for each patient. Even though controversial, computed tomography (CT) preoperative staging in colorectal cancer (CRC) may be beneficial for planning surgery and neoadjuvant treatment, especially when local tumor extension onto surrounding structures or metastatic disease is identified. CT technology has advanced significantly since the debut of the multidetector row CT (MDCT) scanner. Due to developments in CT technology, the potential usefulness of CT in the diagnosis and staging of CRC has piqued attention. In recent studies, MDCT using multiplanar reformations imaging has shown promise in identifying the local extent and nodal involvement of CRC. CT scans are useful because they give functional as well as anatomical information. As a result, it is only normal to assume that CT will improve CRC preoperative staging accuracy. The exact identification of distant metastases is the most crucial additional information provided by CT. CT offers a relative advantage over CT in the assessment of patients with CRC in terms of tumor penetration thru the walls, extracurricular expansion, and regional lymph node metastases. Patients with metastatic lesions that are suggestive but not definitive should get a CT scan.

Low-radiation dose scan protocol for preoperative imaging for dental implant surgery using deep learning-based reconstruction in multidetector CT.

This study aimed to investigate the impact of a deep learning-based reconstruction (DLR) technique on image quality and reduction of radiation exposure, and to propose a low-dose multidetector-row computed tomography (MDCT) scan protocol for preoperative imaging for dental implant surgery. The PB-1 phantom and a Catphan phantom 600 were scanned using volumetric scanning with a 320-row MDCT scanner. All scans were performed with a tube voltage of 120kV, and the tube current varied from 120 to 60 to 40 to 30mA. Images of the mandible were reconstructed using DLR. Additionally, images acquired with the 120-mA protocol were reconstructed using filtered back projection as a reference. Two observers independently graded the image quality of the mandible images using a 4-point scale (4, superior to reference; 1, unacceptable). The system performance function (SPF) was calculated to comprehensively evaluate image quality. The Wilcoxon signed-rank test was employed for statistical analysis, with statistical significance set at p value < 0.05. There was no significant difference between the image quality acquired with the 40-mA tube current and reconstructed with the DLR technique (40DLR), and that acquired with the reference protocol (3.00, 3.00, p = 1.00). The SPF at 1.0 cycles/mm acquired with 40DLR was improved by 156.7% compared to that acquired with the reference protocol. Our proposed protocol, which achieves a two-thirds reduction in radiation dose, can provide a minimally invasive MDCT scan of acceptable image quality for dental implant surgery.

Can epicardial and pericardial adipose tissue volume predict the presence and severity of coronary artery disease?

PurposeExcessive accumulation of free fatty acids in the coronary arteries can lead to coronary artery disease (CAD). Quantification of epicardial adipose tissue (EAT) and pericardial adipose tissue (PAT) is beneficial to understand its relationship with CAD, hypertension (HT), and diabetes.Material and methodsThis retrospective study included 54 patients who underwent CT coronary angiogram using a multidetector row CT scanner. The EAT and PAT volumes from cardiac images were quantified using Image J software. The severity of CAD was graded using the CAD-RADS score.ResultsTwenty-nine patients had no CAD, 21 patients had significant CAD, and 4 patients had insignificant CAD. Out of 21 patients with significant CAD, 14 had involvement of multiple coronary arteries. The EAT and PAT volumes were higher in patients with HT, DM, CAD-present group and significant-CAD-present group, but this was not statistically significant except the PAT volume with respect to diabetes. Significant correlation was found between EAT volume and calcium score (p = 0.035) and between EAT volume and total cholesterol level (p = 0.017). Significant differences in the EAT volumes were found in different CAD-RADS categories in the right coronary artery (RCA). From the threshold values, it was observed that CAD can develop in LAD even at lower of EAT and PAT volumes.ConclusionsQuantification of EAT and PAT volumes is beneficial in understanding its relationship with the presence and severity of coronary artery disease and its risk factors.

A novel method for predicting perineural invasion of distal cholangiocarcinoma on multidetector-row computed tomography.

Excessive perineural invasion (PNI) is associated with a high risk of radial margin (RM) positivity and a poor prognosis for patients with distal cholangiocarcinoma (DCC). This study evaluates a new method of predicting the extent of PNI preoperatively. The subjects of this retrospective study were 201 patients who underwent resection for DCC between 2002 and 2018. This study identified the 'periductal enation sign' (PES), defined as the surrounding soft tissue enhancement that appears as an enation from the circumference of the enhanced extrahepatic bile duct on multidetector-row computed tomography (MDCT) scans, as a predictor of PNI. We analyzed the outcomes of the patients in relation to the presence or absence of the PES on MDCT scans. The PES in the PNI-positive group was significantly longer than that in the PNI-negative group. As the length of the PES extended, the grade of PNI increased. A positive PES was defined as a PES length of ≥ 2.0mm. Patients with a positive PES were more frequently positive for RM (23.7% vs. 2.1%) and locoregional recurrence (23.7% vs. 6.3%) and exhibited significantly poorer overall survival than those with a negative PES (30.2% vs. 54.6% at 5years). The presence and extent of PNI can be predicted easily and effectively by the PES length. A positive PES was associated with poor local controllability and a poor prognosis.

Assessing predictors of rheumatoid arthritis-associated interstitial lung disease using quantitative lung densitometry.

To assess predictors of subclinical RA-associated interstitial lung disease (RA-ILD) using quantitative lung densitometry (qLD). RA patients underwent multi-detector row CT scanning at baseline and after an average of 39 months. Scans were analysed with qLD for the percentage of lung parenchyma with high attenuation areas (%HAA: the percentage of voxels of -600 to -250 Hounsfield units). Additionally, a pulmonary radiologist calculated an expertradiologist scoring (ERS) for RA-ILD features. Generalized linear models were used to identify indicators of baseline %HAA and predictors of %HAA change. Baseline %HAA was assessed in 193 RA patients and 106 had repeat qLD assessment. %HAA was correlated with ERS (Spearman's rho = 0.261; P < 0.001). Significant indicators of high baseline %HAA (>10% of lung parenchyma with high attenuation) included female sex, higher pack-years of smoking, higher BMI and anti-CCP ≥200 units, collectively contributing an area under the receiver operator curve of 0.88 (95% CI 0.81, 0.95). Predictors of %HAA increase, occurring in 49% with repeat qLD, included higher baseline %HAA, presence of mucin 5B (MUC5B) minor allele and absence of HLA-DRB1 shared epitope (area under the receiver operator curve = 0.69; 95% CI 0.58, 0.79). The association of the MUC5B minor allele with %HAA change was higher among men and those with higher cumulative smoking. Within the group with increased %HAA, anti-CCP level was significantly associated with a greater increase in %HAA. %HAA, assessed with qLD, was linked to several known risk factors for RA-ILD and may represent a more quantitative method to identify RA-ILD and track progression than expert radiologist interpretation.

Epicardial Adipose Tissue Measured From Computed Tomography Predicts Cardiac Resynchronization Therapy Response in Patients With Non-ischemic Systolic Heart Failure.

Background: Epicardial adipose tissue (EAT) has been linked with the pathogenesis of heart failure (HF). Limited data have been reported about the clinical value of EAT for cardiac resynchronization therapy (CRT) in non-ischemic systolic HF. We aimed to explore the values of EAT measured from CT to predict the response to CRT in patients with non-ischemic systolic HF.Methods: Forty-one patients with CRT were consecutively recruited for our study. All patients received both gated resting Single Photon Emission CT (SPECT) myocardial perfusion imaging (MPI) and dual-source multi-detector row CT scans. EAT thickness was assessed on both the parasternal short and horizontal long-axis views. The area of EAT was calculated at the left main coronary artery level. Left ventricular systolic mechanical dyssynchrony (LVMD) was measured by phase standard deviation (PSD) and phase histogram bandwidth (PBW). The definition of CRT response was an improvement of 5% in left ventricular ejection fraction (LVEF) at 6 months after CRT implantation.Results: After 6 months of follow-up, 58.5% (24 of 41) of patients responded to CRT. A greater total perfusion deficit (TPD) was observed in the left ventricle, and a narrower QRS complex was observed in the nonresponse group than in the response group (p < 0.05). Meanwhile, the systolic PSD and systolic PBW were statistically greater in the CRT group with no response than in the response group (p < 0.05). Meanwhile, the baseline QRS duration, TPD, systolic PSD, systolic PBW, EAT thicknesses of the left ventricular (LV) apex, right atrioventricular (AV) groove, and left AV groove were all significantly related to the CRT response in the univariate logistic regression analysis. Furthermore, the QRS duration and EAT thicknesses of the right AV groove and left AV groove were independent predictors of CRT response in the multivariate logistic regression analysis.Conclusions: The EAT thickness of the left AV groove in patients with non-ischemic systolic HF is associated with the TPD of LV and LV systolic dyssynchrony. The EAT thickness of the AV groove has a good predictive value for the CRT response in patients with non-ischemic systolic HF.

Predictors of Left Ventricular Outflow Tract Obstruction After Transcatheter Mitral Valve Replacement in Severe Mitral Annular Calcification: An Analysis of the Transcatheter Mitral Valve Replacement in Mitral Annular Calcification Global Registry.

[Figure: see text].

Sex differences in left ventricular remodelling in patients with severe aortic valve stenosis.

Women with severe aortic stenosis (AS) have better long-term outcome after transcatheter aortic valve implantation (TAVI) but worse survival after surgical aortic valve replacement compared with men. Whether this is related to sex differences in left ventricular (LV) remodelling is unknown. The aim of this study was to examine the sex differences in LV remodelling with multidetector row computed tomography (MDCT) and outcome in patients with severe AS undergoing TAVI between 2007 and 2018. A total of 289 patients (age 80 ± 6 years, 54% male) were included. LV volumes, mass, and function were analysed on pre-procedural MDCT scans. Women showed smaller LV volumes and mass compared with men. Patients were classified into four LV remodelling patterns: concentric hypertrophy (50%) was the most frequent pattern of LV remodelling followed by eccentric hypertrophy (33%), normal geometry (13%), and concentric remodelling (4%). Men showed more concentric remodelling compared with women (91% vs. 9%, respectively, P = 0.011). However, no differences were observed in the remaining LV remodelling patterns. During a median follow-up of 3.8 (IQR 2.2-5.1) years after TAVI, 87 (30%) patients died. Women demonstrated better outcome after TAVI compared with men (log-rank χ2 = 4.29, P = 0.038). No association was observed between the interaction of the LV remodelling patterns and sex with outcome. LV concentric hypertrophy and eccentric hypertrophy are similarly observed in men and women with severe AS but concentric remodelling was more common in men. Women demonstrated better outcome after TAVI when compared with men. The interaction between the LV remodelling patterns and sex was not associated with survival.

Diagnostic and Prognostic Accuracy of Aortic Valve Calcium Scoring in Patients With Moderate-to-Severe Aortic Stenosis.

Background: Assessing the true severity of aortic stenosis (AS) remains a challenge, particularly when echocardiography yields discordant results. Recent European and American guidelines recommend measuring aortic valve calcium (AVC) by multidetector row computed tomography (MDCT) to improve this assessment.Aim: To define, using a standardized MDCT scanning protocol, the optimal AVC load criteria for truly severe AS in patients with concordant echocardiographic findings, to establish the ability of these criteria to predict clinical outcomes, and to investigate their ability to delineate truly severe AS in patients with discordant echocardiographic AS grading.Methods and Results: Two hundred and sixty-six patients with moderate-to-severe AS and normal LVEF prospectively underwent MDCT and Doppler-echocardiography to assess AS severity. In patients with concordant AS grading, ROC analysis identified optimal cut-off values for diagnosing severe AS using different AVC load criteria. In these patients, 4-year event-free survival was better with low AVC load (60–63%) by these criteria than with high AVC load (23–26%, log rank p < 0.001). Patients with discordant AS grading had higher AVC load than those with moderate AS but lower AVC load than those with severe high-gradient AS. Between 36 and 55% of patients with severe LG-AS met AVC load criteria for severe AS. Although AVC load predicted outcome in these patients as well, its prognostic impact was less than in patients with concordant AS grading.Conclusions: Assessment of AVC load accurately identifies truly severe AS and provides powerful prognostic information. Our data further indicate that patients with discordant AS grading consist in a heterogenous group, as evidenced by their large range of AVC load. MDCT allows to differentiate between truly severe and pseudo-severe AS in this population as well, although the prognostic implications thereof are less pronounced than in patients with concordant AS grading.

A comparison of breast and lung doses from chest CT scans using organ-based tube current modulation (OBTCM) vs. Automatic tube current modulation (ATCM).

PurposeThe purpose of this work was to estimate and compare breast and lung doses of chest CT scans using organ‐based tube current modulation (OBTCM) to those from conventional, attenuation‐based automatic tube current modulation (ATCM) across a range of patient sizes.MethodsThirty‐four patients (17 females, 17 males) who underwent clinically indicated CT chest/abdomen/pelvis (CAP) examinations employing OBTCM were collected from two multi‐detector row CT scanners. Patient size metric was assessed as water equivalent diameter (Dw) taken at the center of the scan volume. Breast and lung tissues were segmented from patient image data to create voxelized models for use in a Monte Carlo transport code. The OBTCM schemes for the chest portion were extracted from the raw projection data. ATCM schemes were estimated using a recently developed method. Breast and lung doses for each TCM scenario were estimated for each patient model. CTDIvol‐normalized breast (nDbreast) and lung (nDlung) doses were subsequently calculated. The differences between OBTCM and ATCM normalized organ dose estimates were tested using linear regression models that included CT scanner and Dw as covariates.ResultsMean dose reduction from OBTCM in nDbreast was significant after adjusting for the scanner models and patient size (P = 0.047). When pooled with females and male patient, mean dose reduction from OBTCM in nDlung was observed to be trending after adjusting for the scanner model and patient size (P = 0.085).ConclusionsOne specific manufacturer’s OBTCM was analyzed. OBTCM was observed to significantly decrease normalized breast relative to a modeled version of that same manufacturer’s ATCM scheme. However, significant dose savings were not observed in lung dose over all. Results from this study support the use of OBTCM chest protocols for females only.

Preoperative Determination of the Size of the Semitendinosus and Gracilis Tendon by Multidetector Row CT Scanner for Anterior Cruciate Ligament Reconstruction.

Accurately measuring the length and diameter of the hamstring tendon autograft preoperatively is important for planning anterior cruciate ligament (ACL) reconstructive surgery. The purpose of this study was to assess the reliability of three-dimensional computed tomography (3D CT) scanning technique to produce the actual measurement of the gracilis and semitendinosus (GT and ST, respectively) tendon grafts' length and diameter for surgery. Ninety patients were scheduled for ACL reconstruction with hamstring autograft. Before the surgery, patients were examined under the multidetector row CT scanner and the ST and GT tendons were qualitatively measured by a volume-rendering technique. The length of ST and GT was measured with 3D CT compared with the length of the harvested ST and GT. The cross-sectional area (CSA) of ST and GT measured with 3D CT compared with the ST and GT graft diameter. Tendon size measured preoperatively and during surgery were statistically compared and correlated. The GT tendons length and cross-sectional area measured during surgery was both shorter and smaller compared with the ST tendon. GT and ST tendon length were correlated to patients' body index such as the height and weight (p < 0.05). However, the correlation levels were low to medium (r = 0.23-0.49). There was strong correlation between the lengths of GT (r = 0.76; p < 0.001) and ST (r = 0.87; p < 0.001) measured with the 3D CT and tendon length at surgery. There was a moderate correlation between graft diameter measured at surgery and 3D CT cross-sectional area (r = 0.31; p < 0.05). A multidetector row CT scanner can determine the ST and GT tendons' length and diameter. These measurements can be used for preoperative planning to help determine the surgical method and counsel patients on appropriate graft choices prior to surgery.

CT evaluation of bronchogenic carcinoma

HRCT delineation of lung parenchyma down to the level of the secondary pulmonary lobule is possible. Spiral CT introduced in the early 1990’s lead to an increase in utilization CT, a revolution that continued with advent of multi detector row CT (MDTC) scanners more recently. Helical technology permits multiple phases of scanning to be obtained often one contrast injection. In this study CT evaluation of 50 patients with either proven or strongly suspected bronchogenic carcicnoma based on chest radiographs, bronchoscopy, cytology of bronchial washings or pleural fluid, FNAC or clinical examination was done.Before commencing CT examination, all the preceding historical, clinical & laboratory data are recorded.Most of the bronchogenic carcinoma are heterogeneously enhancing (54.3%),with ill defined/ speculated margins (73.9%)and associated with necrosis in 43.47%of cases .calcification rarely found (13%).

Artificial intelligence in image reconstruction: The change is here.

Innovations in CT have been impressive among imaging and medical technologies in both the hardware and software domain. The range and speed of CT scanning improved from the introduction of multidetector-row CT scanners with wide-array detectors and faster gantry rotation speeds. To tackle concerns over rising radiation doses from its increasing use and to improve image quality, CT reconstruction techniques evolved from filtered back projection to commercial release of iterative reconstruction techniques, and recently, of deep learning (DL)-based image reconstruction. These newer reconstruction techniques enable improved or retained image quality versus filtered back projection at lower radiation doses. DL can aid in image reconstruction with training data without total reliance on the physical model of the imaging process, unique artifacts of PCD-CT due to charge sharing, K-escape, fluorescence x-ray emission, and pulse pileups can be handled in the data-driven fashion. With sufficiently reconstructed images, a well-designed network can be trained to upgrade image quality over a practical/clinical threshold or define new/killer applications. Besides, the much smaller detector pixel for PCD-CT can lead to huge computational costs with traditional model-based iterative reconstruction methods whereas deep networks can be much faster with training and validation. In this review, we present techniques, applications, uses, and limitations of deep learning-based image reconstruction methods in CT.

Optimization of paranasal sinus CT procedure: Ultra-low dose CT as a roadmap for pre-functional endoscopic sinus surgery.

To assess image quality and radiation dose associated with ultra-low dose CT protocol for patients with benign paranasal sinus diseases undergoing functional endoscopic surgery (FESS). We scanned the head portion of Alderson RANDO phantom on a second generation, dual-source, multidetector-row CT scanner (Siemens Definition Flash) using standard-dose and five low-dose protocols. Two radiologists assessed the image quality for each protocol to determine best ultra-low-dose protocols for imaging patients with benign paranasal sinus diseases undergoing FESS. The ultra-low-dose CT protocols were then used for scanning. Thereafter, 40 adult patients (age range 18-54years, M:F 23:17) were scanned with the four low dose scanning protocols (10 patients per protocol). On both transverse and coronal reformatted CT images, two radiologists assessed visibility of key anatomic landmarks for FESS on a 2-point scale (1=clear and complete visualization; 2=suboptimal visualization). Data were analyzed with descriptive statistics and Cohen's kappa coefficient for interobserver agreement. In phantom study, the lowest dose scan protocol (CTDIvol 2.1mGy, 70kV, 75 mAs) was unacceptable due to poor image quality. For patient studies, both radiologists gave acceptable image quality scores for ultra-low-dose scan protocol with axial scan mode, automatic tube potential selection and tube current modulation (CTDIvol 2.2mGy; DLP 22.9mGy.cm) with up to 60% lower dose compared to prior standard-dose CT (CTDIvol 5.3mGy; DLP 73.5mGy.cm). Ultra-low-dose CT protocol provides sufficient image quality for scanning patients undergoing functional endoscopic surgery for benign paranasal sinus diseases.