Use of shear wave imaging with intestinal ultrasonography in patients with chronic diarrhea.

OBJECTIVE: A retrospective study was designed to determine the role of shear wave elastography (SWE) and intestinal ultrasonography to differentiate between inflammatory and fibrotic bowel strictures by determining Young's modulus (E) and shear wave dispersion (SWD) and to compare its role with contrast-enhanced computed tomography (CECT) in patients with chronic diarrhea and pain abdomen. METHODS: Seventy-six patients who had increased small bowel thickness (SBWT) >3 mm, and large bowel wall thickness (LBWT) >4 mm on intestinal ultrasonography (IUS) were evaluated in a two-step manner. The first step involved classifying patients with increased SBWT >3 mm and LBWT >4 mm by use of SWE and dispersion into three groups that is group I (fibrotic), group II (inflammatory) thickening, and group III (mixed-fibrosis and inflammatory) wall thickening. In the second step, etiological classification was done using six gray scale features of IUS that is length and degree of bowel thickening, presence of bowel stratification, Limberg grade of vascularity, status of mesenteric fat, juxta bowel status-nodes, fluid, and fistula formation to reach to a definitive diagnosis. These findings were compared with findings on CECT. Twenty-three patients had diagnosis confirmed by biopsy while 18 underwent surgery with histologic confirmation of operative findings. The sensitivity, specificity and AUROC for both modalities were compared. RESULTS: Group I that is fibrotic group had 33 patients with fibrotic strictures of which fibrotic Crohn's disease (CD)and tuberculosis of the bowel were the dominant types followed by neoplastic and infective causes. In Group II that is inflammatory there were 32 patients with predominantly infective ileo-colitis, and ulcerative colitis patients while 11 patients were present in group III that is (mixed fibrotic and inflammatory) type of bowel wall thickening and were patients of inflammatory CD, infective ileo-colitis. The presence of length of bowel involvement, Limberg grade, mesenteric fat proliferation, and SBWT>9 mm were the statistically significant parameters on IUS which helped to reach to final diagnosis. The sensitivity and specificity of combined SWE with SWD and IUS were 100% and 99% while that of CECT was 78% and 96% respectively with AUROC of 100% and 64%. CONCLUSION: SWI combined with IUS in a two-step manner is an accurate way to evaluate patients with chronic diarrhea who have increased SBWT and is not only able to differentiate inflammatory from fibrotic bowel wall thickening but also helps to form an etiological diagnosis.

Differentiating malignant from benign thickening of the gallbladder wall by the use of acoustic radiation force impulse elastography.

OBJECTIVES: The purpose of this study was to determine whether real-time elastography can differentiate gallbladder carcinoma from benign gallbladder wall thickening. METHODS: Sonographic and real-time elastographic examinations were done in 125 of 2000 consecutive patients who had an increased gallbladder wall thickness of more than 3 mm. Shear wave velocities were determined for a normal gallbladder wall, a benign thickened gallbladder wall, and gallbladder carcinoma, and a value of 2.7 m/s was set as the cutoff to differentiate between benign and malignant wall thickening. Virtual touch and color maps of the gallbladder wall were also obtained. The final diagnosis was confirmed by histopathologic examination of the resected gallbladder or by guided fine-needle aspiration cytologic examination. Statistical analysis was done to determine the sensitivity and specificity of elastography for gallbladder carcinoma and benign wall thickening. Student t test and area under the receiver operating characteristic curve analyses were done to determine the statistical significance of the results. RESULTS: Elastography had sensitivity and specificity of 100% and 91.3%, respectively, for diagnosing gallbladder carcinoma with a mean shear wave velocity of 3.41 m/s (P < .0001) and an area under the curve of 0.92. False-positive findings of acute cholecystitis occurred in 8.5% of cases, which also had an increased shear wave velocity of greater than 2.7 m/s. The overall accuracy of elastography for differentiating gallbladder carcinoma from benign wall thickening was 92.8%. CONCLUSIONS: Elastography is an accurate technique for differentiating between benign and malignant gallbladder wall thickening and can be combined with sonography as the prime imaging tool for diagnosing gallbladder carcinoma at an early stage.

Onsite Computed Tomography Fractional Flow Reserve in Patients with Suspected Stable Coronary Artery Disease Initial Experience.

Introduction Computed tomographic coronary angiographic (CTCA) has evolved into a robust technique to detect significant stenosis; however, there is a discordance in the anatomic and functional significance of stenosis. Therefore, patients with stable coronary artery disease need to be further evaluated before deciding for any revascularization procedure. Material and Methods A total of 100 consecutive patients of suspected stable coronary artery disease who underwent CTCA were evaluated for functional significance of lesions using onsite computed tomography fractional flow reserve (CTFFR) and the results were compared for detection of both significant and hemodynamically significant/severe stenosis on per vessel and per patient basis and differences were statistically analyzed. Impact of these differences were analyzed for the final outcome and management plan. Results CTCA detected 33 patients with severe stenosis, while 54 patients had hemodynamically significant stenosis on CTFFR. The sensitivity and specificity of CTCA for the detection of significant coronary artery stenosis per vessel basis were 97.7 and 93.3%, respectively, with a negative predictive value of 98.0%. For severe coronary artery stenosis, sensitivity, specificity, and negative and positive predictive values were 51.6, 89, 68.8, and 80%, respectively, on per vessel basis with CTCA. On per patient basis, CTCA showed as sensitivity and specificity of 61 and 84%, respectively, with area under curve (AUC) being 0.92 and 0.67 for significant and severe stenosis, respectively. Discussion Onsite CTFFR is a useful tool to calculate functionally significant stenosis and also improves the sensitivity and specificity of CTCA. CTFFR detected 12% more stenotic vessels in the present study on per vessel basis and 21% on per patient basis.

Use of Artificial Intelligence to Triage Patients with Flu-Like Symptoms Using Imaging in Non-COVID-19 Hospitals during COVID-19 Pandemic: An Ongoing 8-Month Experience.

Background Evaluation of suspected coronavirus disease-2019 (COVID-19) patient is a diagnostic dilemma as it commonly presents like influenza in early stages. Studies and guidelines have emerged both for and against the use of imaging as a frontline tool to investigate such patients. Reverse transcriptase-polymerase chain reaction (RT-PCR) is suggested as the backbone of diagnosis. We designed and tested a diagnostic algorithm using artificial intelligence (AI) to determine the role of imaging in the evaluation of patients with acute flu-like presentation. Materials and Methods Overall, 3,235 consecutive patients with flu-like presentation were evaluated over a period of 240 days. All patients underwent plain radiographs of chest with computer-aided detection for COVID-19 (CAD4COVID) AI analysis. Based on the threshold scores, they were divided into two groups: group A (score < 50) and group B (score > 50). Group A patients were discharged and put on routine symptomatic treatment and follow-up with RT-PCR, while group B patients underwent high-resolution computed tomography (HRCT) followed by COVID-19 AI analysis and RT-PCR test. These were then triaged into COVID-19 and non-COVID-19 subgroups based on COVID-19 similarity scores by AI, and lung severity scores were also determined. Results Group A had 2,209 (68.3%) patients with CAD4COVID score of <50 while 1,026 (31.7%) patients comprised group B. Also, 825 (25.5%) patients were COVID-19 positive with COVID-19 similarity threshold of >0.85 on AI. RT-PCR was positive in 415 and false-negative in 115 patients while 12 patients died before the test could be done. The sensitivity and specificity of CAD4COVID AI analysis on plain radiographs for detection of any lung abnormality combined with HRCT AI analysis was 97.9% and 99% using the above algorithm. Conclusion Combined use of chest radiographs and plain HRCT with AI-based analysis is useful and an accurate frontline tool to triage patients with acute flu-like symptoms in non-COVID-19 health care facilities.

Evaluation of Low-kVp Low-Volume Iodinated Contrast Protocol for Coronary CT Angiography Using Retrospective ECG Gating.

Objective The aim of this study was to evaluate the use of low peak kilovoltage (kVp) low-volume iodinated contrast protocol for performing coronary computed tomography (CT) angiography (CCTA) in patients using retrospective electrocardiogram (ECG) gating. Materials and Methods Hundred prospective patients undergoing CCTA were studied in two groups, A and B, using 70 kilovoltage (kV) and 120 kV protocols with half and standard intravenous volumes of injected iodinated contrast, respectively. All patients had heart rates less than 100 beats/min and body mass index (BMI) less than 31 kg/m 2 . Both the groups were evaluated for signal-to-noise (S/N) and contrast-to-noise (C/N) ratios along with radiation dose delivered in millisievert (mSv), and for image quality (IQ), on per patient and per segment basis. Results Patients with group A showed statistically reduced radiation dose of 1.86 mSv compared with 6.86 mSv in group B patients. Marked reduction in image noise with statistically improved S/N and C/N ratios in all coronary vessels was seen in group A. S/N ratios in group A were 20.25, 18.68, 19.04, 17.41, and 18.69 for aorta, left main, left anterior descending, right coronary, and left circumflex arteries while they were 13.34, 11.12, 10.96, 9.74, and 8.67 in group B patients. C/N ratios were also higher in all vessels in group A patients, that is, 19.48, 19.48, 19.04, 19.48, and 17.68, compared with group B patients, who had 12.43, 10.03, 9.23, 9.57, and 8.23 ratios ( p < 0.0001). No significant difference in IQ per patient and per vessel was seen between both the groups. Discussion Retrospective ECG-gated low-kVp low-volume iodinated contrast protocol provides good diagnostic quality angiograms in patients with BMI up to 31 kg/m 2 and with heart rates of less than 100 beats/min with three times reduced radiation dose. The reduced volume of contrast reduces the cost as well as the chance of contrast-induced nephropathy.

Real-time elastography in acute appendicitis.

OBJECTIVE: This study was done to evaluate the role of real-time Elastography (ES) in the diagnosis and staging the severity of acute appendicitis. METHODS: Forty patients with acute pain in the right iliac fossa were evaluated using ES and sonography. All patients with a diagnosis of acute appendicitis on ES were also staged for the severity of appendicular inflammation and later underwent surgery, and the findings on imaging were confirmed and results compared. The sensitivity and specificity for ES and sonography were then calculated. RESULTS: Elastography had sensitivity and specificity of 100% each, whereas sonography had sensitivity of 88% and specificity of 100%. Elastography also depicted the severity of inflammation, with 12 patients having mild, 8 having moderate, and 5 having severe appendicitis. CONCLUSIONS: Combining ES with sonography improves the sensitivity in detection of acute appendicitis and can also be used to triage the severity of inflammation in such patients.

Multispiral computed tomographic angiography of renal arteries of live potential renal donors: a review of 118 cases.

OBJECTIVES: Review of the angiographic data of 118 live kidney donors was performed to assess the renal vessel anatomy; compare the findings with the perioperative findings using multislice spiral (MS) computed tomographic angiography (CTA) with the use of 50 mL of intravenous contrast; determine the sensitivity of this technique in the workup of live potential renal donors; and finally to discuss and compare the results of the present study with the reported results using single-slice spiral (SS) CTA, magnetic resonance angiography (MRA), and conventional angiography (CA). METHODS: Retrospective analysis of the angiographic data of 118 of prospective live kidney donors was performed. All donors underwent renal angiography on MSCTA scanning using 50 mL of intravenous contrast with 1.25-mm slice thickness followed by maximum intensity projection and virtual rendering techniques postprocessing algorithms. Analysis was made on imaging and intraoperatively for the number of renal arteries as well as their bifurcation pattern, location, vessel caliber, length, and venous anatomy, and these were then compared with each other. RESULTS: MSCTA showed clear delineation of the main renal arteries in all the donors with detailed vessel morphology. The study also revealed a 100% sensitivity in the detection of accessory renal vessels, which had an overall incidence of 26.67%, with the most common distribution in the perihilar region. CONCLUSIONS: The present study showed a 100% sensitivity and specificity in the visualization and detection of main and accessory renal vessels with the use of only 50 mL of intravenous contrast with similar results seen with CA which has so far been considered the "gold standard." The results on MSCTA were also better than those with the use of SSCTA and MRA in the workup of liver renal donors, with the above technique also proving to be more cost effective. The overall incidence of supernumerary vessels was the same as reported in the literature; however, a higher incidence of single aberrant vessels was seen on the right side, contrary to what has been suggested so far and was attributable to improved detection of accessory vessels less then 2 mm in diameter.

Technical note: Radiofrequency ablation of hepatocellular carcinoma with contrast-enhanced ultrasound guidance: First Indian experience.

Radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC) is an established alternative treatment to surgery and intra-arterial chemotherapy, usually performed under contrast-enhanced CT scan guidance. We describe our experience with the use of contrast-enhanced ultrasound and contrast dynamics analysis for planning and monitoring RFA in a patient with HCC.

Real-time elastography in the detection of prostate cancer in patients with raised PSA level.

The study was done to evaluate the role of real-time elastosonography (ES) in the detection of prostate cancer (PCa) in 50 consecutive patients with raised PSA level and to determine whether ES can be of use to perform a targeted biopsy. Fifty consecutive patients with raised PSA levels underwent transrectal ultrasound (TRUS) and ES examination. ES images with adequate compression and a quality factor of more than 50% were analyzed for areas of increased glandular stiffness. The ES findings were correlated with the targeted and 10-core biopsy and sensitivity, specificity calculated on per patient and per core basis. ES showed a sensitivity and specificity of 91.7% and 86.8% on per patient basis, respectively, with a false positive rate of 13%. The calculated sensitivity and specificity on per core basis of ES targeted biopsy was 72.5% and 100% compared with 100% and 81% of 10-core systematic biopsy group. The study concludes that combining ES with TRUS significantly improves the sensitivity to detect carcinoma prostate in patients with raised PSA, however, ES is unable to differentiate PCa from chronic prostatitis. The use of ES for targeted biopsy also improves the specificity over a 10-core systematic biopsy.

Real-time elastography in differentiating metastatic from nonmetastatic liver nodules.

The study was designed to evaluate the role of real-time elastography in differentiating metastatic from nonmetastatic liver nodules, which include various benign lesions, hepatocellular carcinoma (HCC) nodules and lymphoma. Out of 1000 prospective patients who underwent abdominal ultrasound (US) examination, 48 patients had liver nodules. Nodule stiffness was determined by real-time elastography (ES) using color maps and shear wave velocity (SWV) and nodules having marked stiffness or SWV of more than 2.5 m/s were diagnosed as metastatic. The final diagnosis was made on fine needle aspiration cytology. No statistically significant differences were seen on elastomaps in the stiffness of metastatic and nonmetastatic nodules (p = 0.16) while SWV showed statistically significant differences in the strain velocities of benign, metastatic and heptocellular carcinoma nodules p < 0.0001 and < 0.008, respectively. At a cutoff value of SWV 2.5 m/s, the sensitivity, specificity and false positive to detect metastatic nodules by ES were 88%, 83% and 16%, respectively. When the SWV cut off value was set at 2.0 m/s the sensitivity, specificity and false positive were 94%, 70% and 29%, respectively. The study showed that estimation of SWV by ES at a cut off value of 2.5 m/s was a better and a more useful tool in diagnosing both solid and necrotic metastatic liver nodules compared with the color stiffness maps alone.

Endovenous ablation of saphenofemoral insufficiency: analysis of 100 patients using RF closure fast technique.

Chronic venous insufficiency is a common problem leading to varicose veins of lower limbs which was traditionally being treated with ligation and stripping. Endovenous ablation is an attractive alternative minimally invasive technique to treat such patients. We analysed the results of 100 consecutive patients treated with Radiofrequency based endovenous ablation using Closure Fast Catheter. Retrospective analysis of 100 consecutive patients with chronic venous insufficiency treated at our institution was done. All patients were classified pre and post procedure based on clinical, etiologic, anatomic and pathophyslogical classification, Venous clinical severity and Venous disablitity scores alongwith color doppler examination with follow up done at 2 weeks, 3 months and one year for any disease recurrence or residual symptoms. 97 of the 100 patients treated at 3 months and at 1 year showed good reduction of venous clinical severity and Venous disability scores to 0. Doppler showed complete closure of saphenofemoral junction and long saphenous vein at 2 weeks with no recanalisation at one year. No thrombus formation was observed. Minor complications like ecchymosis was seen in 9 patients and thrombophlebitis in 4 patients. Endovenous ablation using radiofrequency with Closure Fast technique showed improved short and long term results in patients with venous insufficiency with 100% closure seen on doppler studies along with lesser complications and no thrombus formation due shortened procedure time and improved catheter design.

Congenital intrahepatic portosystemic shunt--an incidental rare anomaly.

Congenital intrahepatic shunts are rare anomalies that are usually incidental in a child who undergoes an ultrasound examination for some other reasons. Early diagnosis is important, because the condition can lead to hepatic encephalopathy and hypoglycemia. Author's would like to describe the findings of one such patient diagnosed to be having congenital intrahepatic shunt and discuss the clinical importance of this condition.