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.

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.

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.

Deep-learning models for differentiation of xanthogranulomatous cholecystitis and gallbladder cancer on ultrasound.

BACKGROUND: The radiological differentiation of xanthogranulomatous cholecystitis (XGC) and gallbladder cancer (GBC) is challenging yet critical. We aimed at utilizing the deep learning (DL)-based approach for differentiating XGC and GBC on ultrasound (US). METHODS: This single-center study comprised consecutive patients with XGC and GBC from a prospectively acquired database who underwent pre-operative US evaluation of the gallbladder lesions. The performance of state-of-the-art (SOTA) DL models (GBCNet-convolutional neural network [CNN] and RadFormer, transformer) for XGC vs. GBC classification in US images was tested and compared with popular DL models and a radiologist. RESULTS: Twenty-five patients with XGC (mean age, 57 ± 12.3, 17 females) and 55 patients with GBC (mean age, 54.6 ± 11.9, 38 females) were included. The performance of GBCNet and RadFormer was comparable (sensitivity 89.1% vs. 87.3%, p = 0.738; specificity 72% vs. 84%, p = 0.563; and AUC 0.744 vs. 0.751, p = 0.514). The AUCs of DenseNet-121, vision transformer (ViT) and data-efficient image transformer (DeiT) were significantly smaller than of GBCNet (p = 0.015, 0.046, 0.013, respectively) and RadFormer (p = 0.012, 0.027, 0.007, respectively). The radiologist labeled US images of 24 (30%) patients non-diagnostic. In the remaining patients, the sensitivity, specificity and AUC for GBC detection were 92.7%, 35.7% and 0.642, respectively. The specificity of the radiologist was significantly lower than of GBCNet and RadFormer (p = 0.001). CONCLUSION: SOTA DL models have a better performance than radiologists in differentiating XGC and GBC on the US.

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.

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.

Early vs. late percutaneous catheter drainage of acute necrotic collections in patients with necrotizing pancreatitis.

PURPOSE: It is recommended to drain the pancreatic fluid collections later in the course of the acute necrotizing pancreatitis (ANP). However, earlier drainage may be indicated. We compared early (≤ 2 weeks) vs. late (3rd to 4th week) percutaneous catheter drainage (PCD) of acute necrotic collections (ANC). MATERIALS AND METHODS: This retrospective study comprised ANP patients who underwent PCD of ANC. The diagnosis of ANP was based on revised Atlanta classification criteria and computed tomography performed between 5 and 7 days of illness. Patients were divided into two groups [1st 2 weeks (group I) and 3rd-4th weeks (group II)] based on the interval between the onset of pain and insertion of catheter. The technical success, clinical success, complications, and clinical outcomes were compared between the two groups. RESULTS: One hundred forty-eight patients (74 in each group) were evaluated. The procedures were technically successful in all patients. The clinical success rate was 67.6% in group I vs. 77% in group II (p = 0.069). The incidence of complications was significantly higher in group I (n = 12, 16%) than group II (n = 4, 5.4%) (p = 0.034). These included 15 minor (11 in group I and 4 in group II) and one major complication (group I). Of the clinical outcomes, the need for surgery was significantly higher in group I than in group II (13 patients vs. 5 patients, p = 0.031). CONCLUSION: Early PCD is as technically successful as late PCD in the management of ANC. However, early PCD is associated with higher surgical rate and higher incidence of complications.

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.

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.

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.

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.

Drainage of pancreatic fluid collections in acute pancreatitis: A comprehensive overview.

Moderately severe and severe acute pancreatitis is characterized by local and systemic complications. Systemic complications predominate the early phase of acute pancreatitis while local complications are important in the late phase of the disease. Necrotic fluid collections represent the most important local complication. Drainage of these collections is indicated in the setting of infection, persistent or new onset organ failure, compressive or pressure symptoms, and intraabdominal hypertension. Percutaneous, endoscopic, and minimally invasive surgical drainage represents the various methods of drainage with each having its own advantages and disadvantages. These methods are often complementary. In this minireview, we discuss the indications, timing, and techniques of drainage of pancreatic fluid collections with focus on percutaneous catheter drainage. We also discuss the novel methods and techniques to improve the outcomes of percutaneous catheter drainage.

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.

Abbreviated non-enhanced magnetic resonance imaging in patients with acute necrotizing pancreatitis.

AIM: To investigate the performance of T2-weighted abbreviated magnetic resonance imaging (T2W-AMRI) protocol in evaluating patients with acute necrotizing pancreatitis (ANP). METHODS: A retrospective analysis of consecutive hospitalized patients with ANP who underwent MRI (contrast-enhanced, CE or non-contrast, NC) between January 2017 and November 2020 was performed. The T2W-AMRI and complete MRI (cMRI) sequences were anonymized, and subsequently, two separate sets of data (AMRI and cMRI) were created for presentation to the radiologists involved in reading the data. The T2W-AMRI was based on a single-axial T2 half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequence. The pancreatic and extrapancreatic findings were recorded and tabulated independently by two radiologists on T2W-AMRI and cMRI. In addition, the interobserver agreement and association of findings between T2W-AMRI and cMRI were analyzed. RESULTS: Twenty-eight patients (mean age 31.7 ± 12.2 years, 17 females) were included. Thirteen patients had CE-cMRI, while the rest underwent NC-cMRI. There was no significant difference in the identification of pancreatic necrosis on T2W-AMRI vs. cMRI (p = 1.00). However, T2W-AMRI underestimated necrosis in one patient. Collections were accurately detected in all patients on T2W-AMRI. The mean size of the collection was larger on cMRI (6.5 ± 3.7 cm) than T2W-AMRI (6 ± 3.7 cm) with p = 0.006. cMRI detected more patients with disrupted pancreatic duct (n = 9) than T2W-AMRI (n = 6). However, the difference was not statistically significant (p = 0.375). There was a good to an excellent interobserver agreement between the readers for T2W-AMRI (k = 0.62-1). CONCLUSION: T2W-AMRI may offer a suitable alternative to cMRI in ANP, especially severe disease, as it can be acquired rapidly without the need for contrast injection.

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.

Value of neutrophil-lymphocyte ratio in evaluating response to percutaneous catheter drainage in patients with acute pancreatitis.

BACKGROUND: Early prediction of response to percutaneous catheter drainage (PCD) of necrotic collections in acute pancreatitis (AP) using simple and objective tests is critical as it may determine patient prognosis. The role of white blood cell (WBC) count and neutrophil-lymphocyte ratio (NLR) has not been assessed as a tool of early prediction of PCD success and is the focus of this study. AIM: To assess the value of WBC and NLR in predicting response to PCD in AP. METHODS: This retrospective study comprised consecutive patients with AP who underwent PCD between June 2018 and December 2019. Severity and fluid collections were classified according to the revised Atlanta classification and organ failure was defined according to the modified Marshall Score. WBC and NLR were monitored 24 h prior PCD (WBC-0/NLR-0) and 24 h (WBC-1/NLR-1), 48 h (WBC-2/NLR-2) and 72 h (WBC-3/NLR-3) after PCD. NLR was calculated by dividing the number of neutrophils by the number of lymphocytes. The association of success of PCD (defined as survival without the need for surgery) with WBC and NLR was assessed. The trend of WBC and NLR was also assessed post PCD. RESULTS: One hundred fifty-five patients [median age 40 ± 13.6 (SD), 64.5% males, 53.5% severe AP] were included in the final analysis. PCD was done for acute necrotic collection in 99 (63.8%) patients and walled-off necrosis in 56 (36.1%) patients. Median pain to PCD interval was 24 ± 69.89 d. PCD was successful in 109 patients (group 1) and 46 patients (group 2) who failed to respond. There was no significant difference in the baseline characteristics between the two groups except the severity of AP and frequency of organ failure. Both WBC and NLR showed an overall decreasing trend. There was a significant difference between WBC-0 and WBC-1 (P = 0.0001). WBC-1 and NLR-1 were significantly different between the two groups (P = 0.048 and 0.003, respectively). The area under the curve of WBC-1 and NLR-1 for predicting the success of PCD was 0.602 and 0.682, respectively. At a cut-off value of 9.87 for NLR-1, the sensitivity and specificity for predicting the success of PCD were calculated to be 75% and 65.4% respectively. CONCLUSION: WBC and NLR can be used as simple tests for predicting response to PCD in patients with acute necrotizing pancreatitis.