Distal coronary artery abnormalities in Kawasaki disease: experience on CT coronary angiography in 176 children.

OBJECTIVE: Precise evaluation of coronary artery abnormalities (CAAs) in Kawasaki disease (KD) is essential. The aim of this study is to determine role of CT coronary angiography (CTCA) for detection of CAAs in distal segments of coronary arteries in patients with KD. METHODS: CTCA findings of KD patients with distal coronary artery involvement were compared with those on transthoracic echocardiography (TTE) during the period 2013-21. RESULTS: Among 176 patients with KD who underwent CTCA (128-Slice Dual Source scanner), 23 (13.06%) had distal CAAs (right coronary-15/23; left anterior descending-14/23; left circumflex-4/23 patients). CTCA identified 60 aneurysms-37 proximal (36 fusiform; 1 saccular) and 23 distal (17 fusiform; 6 saccular); 11 patients with proximal aneurysms had distal contiguous extension; 9 patients showed non-contiguous aneurysms in both proximal and distal segments; 4 patients showed distal segment aneurysms in absence of proximal involvement of same coronary artery; 4 patients had isolated distal CAAs. On TTE, only 40 aneurysms could be identified. Further, distal CAAs could not be identified on TTE. CTCA also identified complications (thrombosis, mural calcification and stenosis) that were missed on TTE. CONCLUSIONS: CAAs can, at times, occur in distal segments in isolation and also in association with, or extension of, proximal CAAs. CTCA demonstrates CAAs in distal segments of coronary arteries, including branches, in a significant number of children with KD-these cannot be detected on TTE. CTCA may therefore be considered as a complimentary imaging modality in children with KD who have CAAs on TTE.

Two-dimensional Shear Wave Elastography: Utility in Differentiating Gallbladder Cancer From Chronic Cholecystitis.

OBJECTIVE: To study the utility of 2D shear wave elastography (SWE) and ascertain cut-off values of shear wave elasticity (SWe) to differentiate benign and malignant thickening of the gallbladder wall. METHODS: This study was a prospective study of patients with symptomatic gallstone disease (GSD, n = 51) and gallbladder cancer (GBC, n = 46) and controls without any biliary disease (n = 46). All the participants underwent 2D USG and SWE of the gallbladder. Grey-scale ultrasound and SWE were done in the different regions in the gallbladder. RESULTS: The median age of the patients with GSD was 49 years (interquartile range [IQR]: 33-55), GBC was 55 years (IQR: 46-65), and controls was 37 years (IQR: 27-48.25). In patients with GBC, asymmetrical mural thickening was the predominant imaging pattern (n = 24, 52.2%). The mean SWe of the abnormal area in GBC (34.99 ± 17.77 kPa [n = 46]) was significantly higher than that of the uninvolved region (18.27 ± 8.12 kPa [n = 35]; P < .01). The mean SWe of the uninvolved region in GBC (18.27 ± 8.12 kPa [n = 35]) was also significantly higher (P < .01) than that of GSD (12.27 ± 4.13 kPa [n = 51]) and controls (10.52 ± 3.75 kPa [n = 46]). On ROC analysis, AUC of 0.927, at a cut-off of 20 kPa, sensitivity was 91.3%, specificity was 83.5%, positive likelihood ratio was 5.54, and negative likelihood ratio was 0.10 to diagnose GBC. CONCLUSION: The 2D SWE is a reliable adjunctive tool to grey-scale USG in differentiating the malignant from benign gallbladder wall and may help to pick up early malignancy in GSD.

MDCT evaluation of distal radius fractures and their association with carpal and distal ulnar fractures.

PURPOSE: The purpose of this study was to evaluate the characteristics of distal radius fractures (DRFs) in patients undergoing multi-detector computed tomography (MDCT) and their association with carpal and distal ulnar fractures. METHODS: This retrospective study analyzed 120 patients, who underwent MDCT for evaluation of DRFs. Two radiologists independently evaluated the data for various fracture characteristics and for associated carpal and distal ulnar fractures. RESULTS: Out of 120 DRFs, 74 were complete articular, 40 were partial articular and only 6 were extra-articular. Displacement was present in 99 fractures and intra-articular step off was present in 73 fractures. A total of 81 carpal bone fractures were identified in 46 (38.3%) patients, with more than one carpal bone fracture in 21 patients. Distal ulnar fractures were detected in 79 patients (65.8%), out of which 67 involved the ulnar styloid. DRFs with intra-articular step off were more frequently associated with carpal bone fracture (p value: 0.021), while displaced DRFs were more frequently associated with distal ulnar fracture (p value <0.001). Interobserver agreement for detection of carpal bone fractures (κ = 0.807) and distal ulnar fractures (κ = 0.923) was excellent. CONCLUSION: Majority of DRFs in patients referred for MDCT were complete articular with high incidence of displacement and intra-articular step off. Associated carpal bone and distal ulna fractures were not uncommon.

Pulmonary Artery Pseudoaneurysm in COVID-19-Associated Pulmonary Mucormycosis: Case Series and Systematic Review of the Literature.

Literature on COVID-19-associated pulmonary mucormycosis (CAPM) is sparse. Pulmonary artery pseudoaneurysm (PAP) is an uncommon complication of pulmonary mucormycosis (PM), and rarely reported in CAPM. Herein, we report five cases of CAPM with PAP managed at our center and perform a systematic review of the literature. We diagnosed PM in those with clinico-radiological suspicion and confirmed it by microbiology or histopathology. We encountered five cases of CAPM with PAP (size ranged from 1 × 0.8 cm to ~ 4.9 × 4.8 cm). All subjects had diabetes and were aged 55-62 years (75% men). In two cases, COVID-19 and mucormycosis were diagnosed simultaneously, while in three others, COVID-19 preceded PM. One subject who underwent surgery survived, while all others died (80% mortality). From our systematic review, we identified one additional case of CAPM with PAP in a transplant recipient. CAPM with PAP is rare with high mortality. Early diagnosis and multimodality management are imperative to improve outcomes.

Role of Shear Wave Elastography of Synovium to Differentiate Rheumatoid and Tubercular Arthritis.

Background: Synovitis is the underlying pathology in various arthritis, and sometimes, it is difficult to differentiate various arthritis clinically or even by imaging. The purpose of our study was to use shear wave elastography (SWE) to evaluate rheumatoid arthritis (RA) and tubercular (TB) arthritis and to differentiate them using synovial stiffness. Methods: The prospective study was performed on Supersonic Imagine Aixplorer Ultrasound (USG) machine using a linear array probe SL10-2 (2-10 MHz). A total of 29 participants, 15 of RA (ACR/EULAR criteria) and 14 of proven TB arthritis were included. Region of interest of 1 mm was applied on the hypertrophied synovium and quantitative SWE data in form of elasticity (kPa) and velocity (m/s) were measured. Discrete categorical data were presented as n (%). Mean values were recorded along with standard deviation and the range of values. To find a maximal cutoff value of elasticity and velocity - receiver operating characteristic curve were plotted. Results: The mean elasticity and velocity values were 54.81 ± 10.6 kPa and 4.2 m/s ± 0.42 for RA and 37 ± 10 kPa and 3.4 ± 0.47 m/s for TB group. Significant difference (P < 0.001) was seen in elastic modulus values between rheumatoid and TB group with cutoff of 43.6 kPa to differentiate the two groups (sensitivity - 86.7% and specificity - 80%). Similar significant (P < 0.001) results were seen with velocity values, with cutoff of 3.76 m/s (sensitivity - 86.7% and specificity - 80%). Conclusion: SWE shows the potential to be a useful adjunct to gray scale and color Doppler USG in differentiating various arthritis on the basis of elastic properties of the synovium. Elastic modulus and velocity are useful SWE quantitative parameters for synovial evaluation and can differentiate RA and TB arthritis.

The role of diffusion-weighted imaging and dynamic contrast-enhanced magnetic resonance imaging for the diagnosis of diabetic foot osteomyelitis: a preliminary report.

Purpose: To assess the role of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and diffusionweighted imaging (DWI) in diagnosing diabetic foot osteomyelitis (DFO). Material and methods: Twenty-five participants with suspected osteomyelitis were included, who underwent MRI including DCE-MRI and DWI sequences. It was subsequently followed by bone biopsy and microbiological analysis (gold standard). The participants were divided into 2 groups based on biopsy results: DFO-positive or DFO-negative. The semi-quantitative DCE-MRI parameters (SI0, SImax, SIrel, wash-in rate [WIR], and type of curve) and apparent diffusion coefficient (ADC) values were subsequently compared between the 2 groups. Results: Out of the 25 cases, 19 were DFO-positive and 6 were DFO-negative on bone biopsy. The SI0, SImax, and WIR were significantly higher in DFO-positive cases (p-value 0.050, 0.023, and 0.004, respectively). No difference was seen in SIrel. 100% negative cases revealed type-I curve, and 94% of positive cases showed type-II curve. SI0 > 143.4 revealed a sensitivity of 94.7% and specificity of 83.3%. SImax had a sensitivity of 89.5% but lower specificity of 67.7% at a cut-off value of 408.35. The most significant difference was seen with WIR; p-value ~0.004. At the cut-off value of > 1.280, it had a specificity and sensitivity of 100% and 76%, respectively. Also, ADC values below 1.57 × 10-3 had a sensitivity of 88.2% and specificity of 80% for diagnosing DFO. Conclusions: DWI and DCE-MRI provide non-invasive sequences, which can help to increase the overall specificity and sensitivity of conventional MRI for the diagnosis of osteomyelitis, differentiating it from acute Charcot's arthropathy.

Percutaneous transthoracic embolisation for massive haemoptysis secondary to peripheral pulmonary artery pseudoaneurysms.

OBJECTIVE: Pulmonary artery pseudoaneurysms (PAPs) are rare, but important and treatable cause of massive haemoptysis. Minimal data exists on their interventional radiology management due to their rarity, especially direct percutaneous injection. Here, we report our experience of direct percutaneous management of such pseudoaneurysms. METHODS: Data of patients presenting to our department from January 2014 to November 2019 was retrospectively analysed, who presented with massive haemoptysis, and CT angiography positive for pulmonary artery pseudoaneurysms. Only patients treated with direct percutaneous intervention were included. Twelve patients who were managed endovascularly were excluded from the study. Observations were tabulated under age, sex, underlying pathology, lobe involved, number and size of the pseudoaneurysm, imaging guidance and embolising agent. Technical and clinical success and complications were then analysed. RESULTS: Twenty-nine pseudoaneurysms were treated in 27 patients with a mean age of 41.4 years. The most common underlying aetiology was tuberculosis (85.1%), with the most common location being bilateral upper lobes (31% each). CT guidance was the most frequently used imaging guidance (26/29). N-butyl cyanoacrylate (NBCA) glue mixture was used in 79.3% and reconstituted thrombin in the remaining 20.7% pseudoaneurysms. Complete technical and clinical success rates were 93.1% and 88.9% respectively. No major complications were seen except for development of significant pneumothorax in one patient. CONCLUSION: Pulmonary pseudoaneurysms are rare but fatal cause for massive haemoptysis. Interventional radiology management via direct percutaneous embolisation is a safe and minimally invasive treatment measure in selective patients, with successful outcomes and minimal complication and recurrence rates. KEY POINTS: • Pulmonary artery pseudoaneurysms are rare but important and treatable cause of massive haemoptysis. • This study shows the advantages of percutaneous management of these pseudoaneurysms as an alternate to endovascular embolisation, in case endovascular embolisation is not feasible or practical. • It is a safe and minimally invasive treatment, with technical success of 93.1% and clinical success of 88.9% in this study.

Overall survival and local recurrence following RFA, MWA, and cryoablation of very early and early HCC: a systematic review and Bayesian network meta-analysis.

OBJECTIVE: To compare overall survival (OS) and local recurrence (LR) following radiofrequency ablation (RFA), microwave ablation (MWA), and cryoablation (CA) for very early and early hepatocellular carcinoma (HCC). METHODS: This systematic review was performed according to the PRISMA guidelines. MEDLINE, Embase, and Cochrane databases were searched. Randomized controlled trials (RCTs) and observational studies were included. OS and LR at 1 year and 3 years were assessed. OS was reported as hazard ratio (HR) with 95% credible intervals (CrI) and LR as relative risk (RR) with 95% CrI, to summarize effect of each comparison. RESULTS: Nineteen studies (3043 patients), including six RCTs and 13 observational studies, met inclusion criteria. For OS at 1 year, as compared to RFA, CA had HR of 0.81 (95% CrI: 0.43-1.51), and MWA had HR of 1.01 (95% CrI: 0.71-1.43). For OS at 3 years, as compared to RFA, CA had HR of 0.90 (95% CrI: 0.48-1.64) and MWA had HR of 1.07 (95% CrI: 0.73-1.50). For LR at 1 year, CA and MWA had RR of 0.75 (95% CrI: 0.45-1.24) and 0.93 (95% CrI: 0.78-1.14), respectively, as compared to RFA. For LR at 3 years, CA and MWA had RR of 0.96 (0.74-1.23) and 0.98 (0.87-1.09), respectively, as compared to RFA. Overall, none of the comparisons was statistically significant. Age of patients and tumor size did not influence treatment effect. CONCLUSIONS: RFA, MWA, and CA are equally effective for locoregional treatment of very early and early HCC. KEY POINTS: • There is no significant difference in the OS and LR (at 1 year and 3 years) following ablation of very early and early HCC with RFA, MWA, and CA. • There was no effect of tumor size on the treatment efficacy. • More RCTs comparing CA with RFA and MWA should be performed.

Comparison of virtual computed tomography enteroscopy using carbon dioxide with small-bowel enteroclysis and capsule endoscopy in patients with small-bowel tuberculosis.

OBJECTIVE: Comparison of virtual CT enteroscopy (VCTE) using carbon dioxide with small-bowel enteroclysis (SBE) and capsule endoscopy (CE) in small-bowel tuberculosis (SBTB). METHODS: This prospective study comprised consecutive patients suspected to have SBTB. VCTE and SBE were performed on the same day and evaluated by independent radiologists. CE was performed within 2 weeks. VCTE was performed following insufflation of carbon dioxide via catheters in the jejunum and anorectum. A contrast-enhanced CT was followed by a delayed non-contrast CT. Image processing was done using virtual colonoscopy software. Findings on VCTE, SBE, and CE were compared. The final diagnosis of SBTB was based on either histopathological or cytological findings, response to antitubercular treatment, or a combination of these. RESULTS: Of the 55 patients in whom VCTE was performed, complete data was available in 52 patients. A final diagnosis of SBTB was established in 37 patients. All patients had VCTE and SBE. CE was performed in 34 patients. Adequate luminal distension was achieved in all patients with SBE and 35 patients with VCTE. SBE showed more strictures in jejunum (10.8%) and ileum (75.7%) compared with VCTE (jejunum, 8.1%, and ileum, 64.9%) and CE (jejunum, 5.9%, and ileum, 61.8%). However, difference was not statistically significant. VCTE revealed a greater length of strictures in both the jejunum and ileum compared with SBE and CE. CONCLUSION: VCTE allows adequate evaluation of the bowel in most patients with SBTB. It allows detection of greater length of abnormality in jejunum and ileum compared with SBE and CE. KEY POINTS: • The use of VCTE using CO2 bowel insufflation in patients with SBTB should be considered. • VCTE allows detection of a greater length of abnormality in the jejunum and ileum.

Computed tomography chest in COVID-19: When & why?

Computed tomography (CT) of the chest plays an important role in the diagnosis and management of coronavirus disease 2019 (COVID-19), but it should not be used indiscriminately. This review provides indications of CT chest in COVID-19 suspect, positive and recovered patients based on the current scientific evidence and our personal experience. CT chest is not indicated as a routine screening modality due to its poor sensitivity and specificity. However, it is useful in a small subset of COVID-19 suspects who test negative on reverse transcription-polymerase chain reaction (RT-PCR) with normal/indeterminate chest X-ray (CXR) but have moderate-to-severe respiratory symptoms and high index of clinical suspicion. CT chest is not indicated in every RT-PCR-positive patient and should be done only in specific clinical scenarios, where it is expected to significantly contribute in the clinical management such as COVID-19 patients showing unexplained clinical deterioration and/or where other concurrent lung pathology or pulmonary thromboembolism needs exclusion. Serial CXR and point-of-care ultrasound are usually sufficient to evaluate the progression of COVID-19 pneumonia. CT chest is also indicated in COVID-19-positive patients with associated co-morbidities (age >65 yr, diabetes, hypertension, obesity, cardiovascular disease, chronic respiratory disease, immune-compromise, etc.) who, despite having mild symptoms and normal/indeterminate CXR, record oxygen saturation of <93 per cent at rest while breathing room air or de-saturate on six-minute walk test. Finally, CT chest plays a crucial role to rule out lung fibrosis in patients recovered from COVID-19 infection who present with hypoxia/impaired lung function on follow up. In conclusion, though CT chest is an indispensable diagnostic tool in COVID-19, it should be used judiciously and only when specifically indicated.

Interventional radiology management of extremity pseudoaneurysms: a pictorial essay.

Pseudoaneurysms are vascular abnormalities caused by a damaging force on an arterial wall, resulting in a persistent extravasation of blood into the surrounding tissue, which can be the result of infection, inflammation, trauma or any iatrogenic procedure. The incidence of extremity artery pseudoaneurysms is rising because of increased number of endovascular procedures. As a number of complications are associated with these false aneurysms, it is important to know the treatment modalities available. Ultrasound is the most common method of diagnosing extremity pseudoaneurysm because of their superficial location. Computed tomographic angiography is the next investigation of choice as it has three-dimensional capability and can help evaluate the vascular bed. Digital subtraction angiography is rarely used for diagnosis alone, and is used only when a therapeutic procedure is planned. Treatment of these pseudoaneurysms has shifted from open surgical procedures to minimally invasive treatment in recent years. The different techniques for tackling these lesions include ultrasound-guided compression, percutaneous thrombin or glue embolisation and endovascular coil or stent graft placement. In this pictorial essay, we review the different treatment modalities so that an interventional radiologist is aware of all the treatments he can offer when confronted with these lesions.

Proposal for a new morphological "combined type" of gallbladder cancer: description of radiopathological characteristics and comparison with other morphological types.

OBJECTIVE: To describe the radiopathological characteristics of a new morphological "combined type" of gallbladder cancer (GBC) and compare it with the mass replacing gallbladder and thickening types of GBC. MATERIALS AND METHODS: The imaging and pathological details of consecutive patients with GBC between August 2020 and December 2022 were retrospectively reviewed. Two radiologists reviewed computed tomography/magnetic resonance imaging in consensus for the morphological type of GBC. The radiologists classified GBC as mass replacing gallbladder, wall thickening, and combined type. The combined type was defined as a mass arising from the thickened wall of an adequately distended gallbladder that extended exophytically into the adjacent liver parenchyma. The presence of calculi, site, and size of lesion, biliary/portal vein involvement, liver, lymph node, and omental metastases was compared among the various types. The pathological characteristics were also compared. RESULTS: Of the 481 patients (median age 55 years, 63.2% females) included in the study, mass replacing gallbladder, wall thickening, and combined-type GBC were seen in 42.8% (206/481), 40.5% (195/481), and 16.6% (80/481) of patients, respectively. In the combined type of GBC, biliary/portal vein involvement was seen in 63.7% (51/80) and 7.5% (6/80) of patients. Liver, lymph node, and omental metastases were seen in 67.5% (54/80), 40% (32/80), and 41.2% (33/80) patients, respectively. Liver metastases were significantly more common in the combined type (p = 0.002). There were no significant differences in pathological characteristics among the various types. CONCLUSION: Combined-type GBC is less common than the mass replacing gallbladder and thickening types and is associated with a higher risk of liver metastases.

Deep-learning enabled ultrasound based detection of gallbladder cancer in northern India: a prospective diagnostic study.

Background: Gallbladder cancer (GBC) is highly aggressive. Diagnosis of GBC is challenging as benign gallbladder lesions can have similar imaging features. We aim to develop and validate a deep learning (DL) model for the automatic detection of GBC at abdominal ultrasound (US) and compare its diagnostic performance with that of radiologists. Methods: In this prospective study, a multiscale, second-order pooling-based DL classifier model was trained (training and validation cohorts) using the US data of patients with gallbladder lesions acquired between August 2019 and June 2021 at the Postgraduate Institute of Medical Education and research, a tertiary care hospital in North India. The performance of the DL model to detect GBC was evaluated in a temporally independent test cohort (July 2021-September 2022) and was compared with that of two radiologists. Findings: The study included 233 patients in the training set (mean age, 48 ± (2SD) 23 years; 142 women), 59 patients in the validation set (mean age, 51.4 ± 19.2 years; 38 women), and 273 patients in the test set (mean age, 50.4 ± 22.1 years; 177 women). In the test set, the DL model had sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) of 92.3% (95% CI, 88.1-95.6), 74.4% (95% CI, 65.3-79.9), and 0.887 (95% CI, 0.844-0.930), respectively for detecting GBC which was comparable to both the radiologists. The DL-based approach showed high sensitivity (89.8-93%) and AUC (0.810-0.890) for detecting GBC in the presence of stones, contracted gallbladders, lesion size <10 mm, and neck lesions, which was comparable to both the radiologists (p = 0.052-0.738 for sensitivity and p = 0.061-0.745 for AUC). The sensitivity for DL-based detection of mural thickening type of GBC was significantly greater than one of the radiologists (87.8% vs. 72.8%, p = 0.012), despite a reduced specificity. Interpretation: The DL-based approach demonstrated diagnostic performance comparable to experienced radiologists in detecting GBC using US. However, multicentre studies are warranted to explore the potential of DL-based diagnosis of GBC fully. Funding: None.

Association between the Distribution of Adipose Tissue and Outcomes in Acute Pancreatitis: A Comparison of Methods of Fat Estimation.

Purpose To assess the correlation between abdominal fat measured at computed tomography (CT) and dual-energy X-ray absorptiometry (DXA) and association with clinical outcomes in patients with acute pancreatitis (AP). Methods This prospective study comprised consecutive patients with AP who underwent abdominal CT and DXA. Fat estimation was done on whole-body DXA and abdominal CT. Correlations among body mass index (BMI), waist circumference (WC), DXA, and CT fat measurements were determined. The association between fat measurements and clinical outcomes was assessed. Results Fifty-nine patients (mean age 38.2 years, 48 males) were included. There was a strong correlation ( r = 0.691-0.799) between DXA and CT fat estimation. In addition, there was a significant association of the visceral adipose tissue (VAT) on DXA and CT with the severity of AP ( p = 0.039 and 0.021, respectively) and the need for drainage of collections ( p = 0.026 and 0.008, respectively). There was a weak correlation of the BMI and WC with the length of hospitalization (LOH) ( r = 0.121, 0.190, respectively) and length of intensive care unit stay (LOICU) ( r = 0.211, 0.197), while there was a moderate to strong correlation of the truncal fat and visceral fat on DXA and total adipose tissue and VAT on CT with LOH ( r = 0.562, 0.532, 0.602 and 0.614, respectively) and LOICU ( r = 0.591, 0.577, 0.636, and 0.676, respectively). Conclusion In conclusion, fat indices measured on DXA and CT are associated with the severity of AP. In addition, the fat measurements at DXA are strongly correlated with those obtained at CT.

Ultra-Low Dose CT Chest in Acute COVID-19 Pneumonia: A Pilot Study from India.

The rapid increase in the number of CT acquisitions during the COVID-19 pandemic raised concerns about increased radiation exposure to patients and the resultant radiation-induced health risks. It prompted researchers to explore newer CT techniques like ultra-low dose CT (ULDCT), which could improve patient safety. Our aim was to study the utility of ultra-low dose CT (ULDCT) chest in the evaluation of acute COVID-19 pneumonia with standard-dose CT (SDCT) chest as a reference standard. This was a prospective study approved by the institutional review board. 60 RT-PCR positive COVID-19 patients with valid indication for CT chest underwent SDCT and ULDCT. ULDCT and SDCT were compared in terms of objective (noise and signal-to-noise ratio) and subjective (noise, sharpness, artifacts and diagnostic confidence) image quality, various imaging patterns of COVID-19, CT severity score and effective radiation dose. The sensitivity, specificity, positive and negative predictive value, and diagnostic accuracy of ULDCT for detecting lung lesions were calculated by taking SDCT as a reference standard. The mean age of subjects was 47.2 ± 10.7 years, with 66.67% being men. 90% of ULDCT scans showed no/minimal noise and sharp images, while 93.33% had image quality of high diagnostic confidence. The major imaging findings detected by SDCT were GGOs (90%), consolidation (76.67%), septal thickening (60%), linear opacities (33.33%), crazy-paving pattern (33.33%), nodules (30%), pleural thickening (30%), lymphadenopathy (30%) and pleural effusion (23.33%). Sensitivity, specificity and diagnostic accuracy of ULDCT for detecting most of the imaging patterns were 100% (p < 0.001); except for GGOs (sensitivity: 92.59%, specificity: 100%, diagnostic accuracy: 93.33%), consolidation (sensitivity: 100%, specificity: 71.43%, diagnostic accuracy: 93.33%) and linear opacity (sensitivity: 90.00%, specificity: 100%, diagnostic accuracy: 96.67%). CT severity score (range: 15-25) showed 100% concordance on SDCT and ULDCT, while effective radiation dose was 4.93 ± 1.11 mSv and 0.26 ± 0.024 mSv, respectively. A dose reduction of 94.38 ± 1.7% was achieved with ULDCT. Compared to SDCT, ULDCT chest yielded images of reasonable and comparable diagnostic quality with the advantage of significantly reduced radiation dose; thus, it can be a good alternative to SDCT in the evaluation of COVID-19 pneumonia.

Imaging Spectrum in Chronic Pulmonary Aspergillosis.

Chronic pulmonary aspergillosis (CPA) is a life-threatening respiratory fungal infection that is almost exclusively seen in patients with preexisting structural lung disease with no or mild immunosuppression. The clinical presentation and imaging findings are varied and often pose a diagnostic challenge; and the disease is often present for a long time before being correctly diagnosed. High-resolution chest computed tomography is the imaging modality of choice because it helps identify various forms of CPA, which can range from a simple aspergilloma and chronic cavitary form, to the subacute invasive and end-stage fibrotic form. The knowledge of the imaging features of this disease cannot be overemphasized because it can assist the clinician in reaching at an early diagnosis and timely initiation of appropriate antifungal therapy, thereby improving patient management and treatment outcome. Moreover, imaging also plays a pivotal role during follow-up in patients of CPA to assess the treatment response. In the current review, we present an illustrative review of radiologic patterns seen in various forms of CPA.

Role of MRI in the Evaluation of Pulmonary Sequel Following COVID-19 Acute Respiratory Distress Syndrome (ARDS).

To evaluate the role of magnetic resonance imaging (MRI) chest as an alternative modality to CT chest for follow-up of patients recovered from severe COVID-19 acute respiratory distress syndrome (ARDS). A total of 25 subjects (16 [64%] men; mean age 54.84 years ± 12.35) who survived COVID-19 ARDS and fulfilled the inclusion criteria were enrolled prospectively. All the patients underwent CT and MRI chest (on the same day) at 6-weeks after discharge. MRI chest was acquired on 1.5T MRI using HASTE, BLADE, VIBE, STIR, and TRUFI sequences and evaluated for recognition of GGOs, consolidation, reticulations/septal thickening, parenchymal bands, and bronchial dilatation with CT chest as the gold standard. The differences were assessed by independent-sample t-test and Mann-Whitney U test. P-value of less than 0.05 was taken significant. There was a strong agreement (k = 0.8-1, P<0.01) between CT and MRI chest. On CT, the common manifestations were: GGOs (n=24, 96%), septal thickening/reticulations (n=24, 96%), bronchial dilatation (n=16, 64%), parenchymal bands (n=14, 56%), pleural thickening (n=8, 32%), consolidation (n=4, 16%) and crazy-paving (n=4, 16%). T2W HASTE, T2W BLADE, and T1 VIBE sequences showed 100% (95% CI, 40-100) sensitivity and 100% (95% CI, 3-100) specificity for detecting GGOs, septal thickening/reticulations, pleural thickening, consolidation, and crazy-paving. The overall sensitivity of MRI for detection of bronchial dilatation and parenchymal bands were 88.9% (95% CI, 77-100) and 92.9% (95% CI, 66-100), respectively; and specificity was 100% (95% CI, 29-100) for both findings. MRI chest, being radiation-free imaging modality can act as an alternative to CT chest in the evaluation of lung changes in patients recovered from COVID-19 pneumonia.

Evaluation of Dynamic Contrast-Enhanced and Oxygen-Enhanced Functional Lung Magnetic Resonance Imaging in Chronic Obstructive Pulmonary Disease Patients.

Chronic obstructive pulmonary disease (COPD) is a chronic respiratory condition characterized by obstruction of airways and emphysematous lung tissue damage, with associated hypoxic vasoconstriction in the affected lung parenchyma. In our study, we evaluate the role of oxygen-enhanced (OE) MRI and dynamic contrast enhanced (DCE)-MRI in COPD patients for assessment of ventilation and perfusion defects and compared their severity with clinical severity. A total of 60 patients with COPD (diagnosed based on clinical and spirometry findings) and 2 controls with normal spirometry and no history of COPD were enrolled. All patients underwent MRI within 1 month of spirometry. OE-MRI was performed by administering oxygen at 12 L/min for 4 min to look for ventilation defects. DCE-MRI was performed by injecting intravenous gadolinium contrast, and perfusion abnormalities were detected by subtracting the non-enhanced areas from the first pass perfusion contrast images. A total of 87% of the subjects demonstrated ventilation and perfusion abnormalities on MRI independently. The lobe-wise distribution of ventilation and perfusion abnormalities correlated well with each other and was statistically significant in all lobes (p < 0.05). The severity of ventilation-perfusion defects also correlated well with clinical severity, as their median value (calculated using a Likert rating scale) was significantly lower in patients in the Global initiative for chronic Obstructive Lung Disease (GOLD) I/II group (3.25) compared to the GOLD III/IV group (7.25). OE- and DCE-MRI provide functional information about ventilation-perfusion defects and their regional distribution, which correlates well with clinical severity in patients with COPD.

Impact of contrast-enhanced versus non-contrast computed tomography on acute kidney injury in acute necrotizing pancreatitis: A randomized controlled trial.

BACKGROUND: The data evaluating contrast-induced-acute kidney injury (AKI) in patients with acute pancreatitis is scarce. This study aimed to compare the frequency of AKI in patients with acute necrotizing pancreatitis undergoing non-contrast computed tomography (NCCT) with those undergoing contrast-enhanced computed tomography (CECT) during hospitalization. METHODS: This prospective randomized controlled trial (CTRI/2019/12/022206) screened consecutive patients with acute pancreatitis for eligibility and randomly allocated patients with acute necrotizing pancreatitis (based on CECT in the first week of illness) and normal renal functions to receive either NCCT or CECT during hospitalization. The incidence of development of new AKI and clinical outcomes was compared between the two groups. Post-hoc analysis was done to adjust for disease severity. RESULTS: As many as 105 patients completed the study as per protocol (NCCT = 45 and CECT = 60). AKI occurred in 36 (34.3%) patients, nine (20%) in the NCCT and 27 (45%) in the CECT group. Contrast induced-AKI occurred in 11 (18.3%) patients, while 25 had AKI secondary to acute pancreatitis. The relative risk (RR) of AKI in the CECT group was 2.25 (95% CI 1.17-4.30, p = .0142). The frequency of intensive care unit (ICU) admission (RR = 2.1, 95% CI 1.34-3.27, p = .0001) and need for drainage of collections (RR = 1.39, 95% CI 1.1-1.7, p = .005) was significantly higher and the length of hospitalization (p = .001) and ICU admission (p = 0.001) were significantly longer in the CECT group. However, when adjusted for the severity of acute pancreatitis, there was no difference in AKI and clinical outcomes between the NCCT and CECT groups. The duration of AKI was significantly longer and the need for dialysis was significantly higher in patients who had AKI secondary to acute pancreatitis compared to those with contrast induced-AKI (p = .003). CONCLUSION: CECT is not significantly associated with AKI in acute necrotizing pancreatitis.

Gastrointestinal involvement in gallbladder cancer: Computed tomography findings and proposal of a classification system.

BACKGROUND: There is relatively scarce data on the computed tomography (CT) detection of gastrointestinal (GI) involvement in gallbladder cancer (GBC). We aim to assess the GI involvement in GBC on CT and propose a CT-based classification. METHODS: This retrospective study comprized consecutive patients with GBC who underwent contrast-enhanced computed tomography (CECT) for staging between January 2019 and April 2022. Two radiologists evaluated the CT images independently for the morphological type of GBC and the presence of GI involvement. GI involvement was classified into probable involvement, definite involvement and GI fistulization. The incidence of GI involvement and the association of GI involvement with the morphological type of GBC was evaluated. In addition, the inter-observer agreement for GI involvement was assessed. RESULTS: Over the study period, 260 patients with GBC were evaluated. Forty-three (16.5%) patients had GI involvement. Probable GI involvement, definite GI involvement and GI fistulization were seen in 18 (41.9%), 19 (44.2%) and six (13.9%) patients, respectively. Duodenum was the most common site of involvement (55.8%), followed by hepatic flexure (23.3%), antropyloric region (9.3%) and transverse colon (2.3%). There was no association between GI involvement and morphological type of GBC. There was substantial to near-perfect agreement between the two radiologists for the overall GI involvement (k = 0.790), definite GI involvement (k = 0.815) and GI fistulization (k = 0.943). There was moderate agreement (k = 0.567) for probable GI involvement. CONCLUSION: GBC frequently involves the GI tract and CT can be used to categorize the GI involvement. However, the proposed CT classification needs validation.