Diagnostic Value of T1 Mapping in Detecting Iron Overload in Indian Patients with Thalassemia Major: A Comparison with T2* Mapping.

Purpose T2* is the gold standard for iron quantification in liver as well as myocardium. In this study, we evaluated the diagnostic accuracy of myocardial T1 mapping for the assessment of myocardial iron overload (MIO) as compared to the T2* mapping in patients with thalassemia major (TM). Methods Consecutive TM patients attending the thalassemia clinic were prospectively enrolled. Magnetic resonance imaging was performed on a 1.5 T scanner (Siemens Healthineers, Germany) using a gradient echo T2* as well as a T1 mapping (MOLLI) sequence done at a mid-ventricular short-axis single 8 mm slice of the left ventricle. Values were analyzed by manually drawing a region of interest in the mid-septum. T2*less than 20ms was used as the cutoff for significant MIO. Results One-hundred three patients (58 males, mean age: 17 ± 7.8 years, mean ferritin: 2009.5 µg/L) underwent cardiovascular magnetic resonance. Median T2* of myocardium was 33.45ms. Nineteen patients (18.4%) had T2*less than 20ms. T1 value was low (<850ms) in all the patients with T2* less than 20 ms. Receiver operating characteristic curve analysis revealed the best cutoff of native T1 mapping value as 850 ms which had high specificity (95.2%), sensitivity (94.2%) and negative predictive value (98.8%) for T2* less than 20ms. There was excellent agreement between T1 and T2* for diagnosis of MIO (Kappa-0.848, p <0.001). We did not find any patient who had normal T1 mapping values but had MIO on T2*. Conclusion T1 and T2* correlate well and normal T1 values may rule out presence of MIO. T1 mapping can act as additional imaging marker for MIO and may be helpful in centers with nonavailability or limited experience of T2*.

Role of Computed Tomography Perfusion in Patients with Liver Cirrhosis and Hepatocellular Carcinoma.

Background: There is a lack of data on computed tomography (CT) perfusion parameters in patients with cirrhosis and the vascular changes that occur with increasing severity of cirrhosis, as well as changes that can occur in the remote/background liver parenchyma when hepatocellular carcinoma (HCC) develops. This study aimed to evaluate the association between CT perfusion parameters in the background liver parenchyma in cirrhotic patients with and without HCC. Methods: This prospective study comprised consecutive patients with cirrhosis with or without HCC. A CT perfusion scan of the whole liver was done on a 128-detector row CT scanner in the four-dimensional spiral mode. Arterial liver perfusion (ALP), portal venous perfusion (PVP), hepatic perfusion index (HPI), blood flow (BF), blood volume (BV), and time to peak (TTP) were assessed. The perfusion parameters of the background liver parenchyma (bALP, bPVP, bHPI, bBF, bBV, and bTTP) were compared between the patients with cirrhosis (group I) and cirrhosis with HCC (group II). Perfusion parameters were also compared between the background liver parenchyma and the HCC in group II. Results: Of the 93 patients evaluated during the study period, 60 patients (30 in group I and 30 in group II, mean age, 54.5 years, 53 men) were included in the analysis. Among the perfusion parameters in the background parenchyma, bPVP was lower and bHPI was higher in group II, suggesting increased hepatic arterial perfusion of even the remote background liver parenchyma in patients with HCC (P = 0.001 and P = 0.01, respectively). Perfusion parameters were significantly altered with increasing severity of cirrhosis (based on Child-Pugh class) both within and between groups. Additionally, there were significant differences in all the perfusion parameters between HCC and the background cirrhotic liver. Conclusion: HPI and PVP of background liver parenchyma were significantly different in cirrhosis with and without HCC and also showed a worsening trend with increasing grades of cirrhosis.

Catheters in vascular interventional radiology: an illustrated review.

The past five decades have seen significant developments in the knowledge and practice of interventional radiology. Advancements in angiographic equipment have made interventional radiology a safe, minimally invasive preferred option in the treatment of a variety of diseases. Today, a range of catheters are available in the armamentarium of the interventional radiologist to suit different needs when conducting diagnostic angiograms or performing interventions in various vascular territories. The hardware required for interventions includes needles, wires, catheters, balloons, and stents. Catheters, in particular, are an invaluable tool for interventionists. The purpose of this review is to describe the identification characteristics, properties, and uses of the common angiographic catheters used in interventional radiology, with a special focus on peripheral vascular interventions (excluding neurointerventions).

Low-dose ultra-high-pitch computed tomography coronary angiography: identifying the optimum combination of iteration strength and radiation dose reduction strategies to achieve true submillisievert scans

PURPOSE: To identify the optimum strength of advanced modeled iterative reconstruction (ADMIRE) to achieve the best subjective and objective image quality when combining three-dose reduction strategies, ultra-high-pitch computed tomography coronary angiography (FLASH CTCA; with single-dose ivabradine to lower heart rate), low tube voltage, and ADMIRE. METHODS: Sixty consecutive patients underwent FLASH CTCA at 100 kVp in this single-center prospective study. Single-dose ivabradine was administered to patients whose heart rate was above 75 bpm. Images were reconstructed using the three highest strengths of ADMIRE (A3, A4, and A5). Objective and subjective image quality (using a Likert scale) were evaluated in the three datasets. RESULTS: The signal strength remained unchanged but mean noise significantly reduced across the increasing strengths of ADMIRE [signal: 513.78 ± 101.7 Hounsfield units (HU) at A3, 515.6 ± 100.5 HU at A4, and 519.7 ± 107.9 HU at A5; noise: 23.4 ± 4.5 HU at A3, 20.2 ± 3.6 HU at A4, and 17.2 ± 3.3 HU at A5]. Signal-to-noise and contrast-to-noise ratios were the highest at A5, and A5 offered significantly higher Likert scores in image noise, vessel sharpness, and overall image quality than A3 or A4. Additionally, A5 did not interfere with image interpretation in any patient. CONCLUSION: Using all three dose reduction strategies during FLASH CTCA along with single-dose ivabradine administration ensures minimal radiation exposure in daily practice. In this study, A5 datasets had the best overall subjective and objective image quality despite their "plastic appearance". In the future, enhanced dose reduction can be obtained by further lowering tube voltages.

Reference values of myocardial native T1 and T2 mapping values in normal Indian population at 1.5 Tesla scanner.

T1 and T2 mapping techniques on cardiovascular magnetic resonance (CMR) provide insights into the myocardial tissue characterisation. We sought to establish the normal reference values of native T1 and T2 mapping in Indian population which can be used subsequently in clinical practice for addressing various cardiac pathologies. This prospective study included consecutive healthy volunteers (18-60 years) who underwent CMR on a 1.5 Tesla scanner using standard protocol. T1 mapping sequence was performed using MOLLI sequence with two different flip angles (FA) (35° and 50°). T2 mapping was performed using a hybrid gradient and spin-echo sequence sequence with two different FA (70° and 12°). Images were analysed with ROIs drawn in all the 16 AHA myocardial segments. 50 volunteers (average age-34 years, males-72%) were included. All the scans were normal. The mean T1 value at 35-degree FA was 946.86 + 14.16 ms and at 50-degree FA was 941.60 + 11.89 ms. The mean T2 mapping value at 70-degree FA was 45.67 + 1.39 ms and at 12-degree FA was 45.61 + 1.47 ms. The mapping values were not statistically different between males and females (all p > 0.2). The T1 and T2 mapping values did not show any significant correlation with LVEF, age, BMI or heart rate (all r < 0.33). The T1 mapping values significantly differ at 35- and 50-degree FAs (p = 0.002). The results establish the normal reference T1 and T2 mapping value for Indian population in institutes using the same protocol and parameters at 1.5 Tesla and may guide future research.

Use of intra-arterial gadolinium as contrast medium for thoracic endovascular aortic repair in a patient with iodine hypersensitivity: an uncharted territory.

We hereby present a case in which we used gadolinium as contrast medium for thoracic endovascular aortic repair in a patient with iodine hypersensitivity.

Detection of cardiac allograft vasculopathy on dual source computed tomography in heart transplant recipients: comparison with invasive coronary angiography.

OBJECTIVE: We aimed to evaluate the diagnostic accuracy (DA) of dual-source CT coronary angiography (DSCTCA) against invasive coronary angiography (ICA) in assessing stenotic cardiac allograft vasculopathy (CAV) in heart transplant (HTX) recipients. METHODS: Consecutive HTX recipients(n = 38) on annual surveillance, underwent DSCTCA prior to ICA on a 192-detector 384-slice DSCT scanner. Cases were classified as no CAV (no stenosis), any CAV (any degree of stenosis) or significant CAV (>50% stenosis). RESULTS: Mean age was 33.66 ± 11.45 years (M:F = 27:11, median time from HTX-23.5 months). Prevalence of any CAV on DSCTCA and ICA was 44.7%(n = 17) and 39.5%(n = 15), respectively and that of significant CAV was 21.1%(n = 8) and 15.8%(n = 6), respectively. 557 (96.7%) segments were interpretable on DSCTCA. Mean radiation dose was 4.24 ± 2.15 mSv. At patient-level, the sensitivity, specificity, positive-predictive value, negative-predictive value (NPV), and DA of DSCTCA for detection of any CAV and significant CAV were 100%, 91.3%, 88.2%, 100%, 94.73% and 100%, 94%, 75%, 100%, 95% respectively. The same on segment-based analysis were 96%, 97.6%, 80%, 99.6%, 97.5% and 100%, 99.6%,86.7%,100%, 99.6%, respectively. There was excellent agreement between the two modalities for detection of any CAV and significant CAV [κ = 0.892 and 0.826 (patient-level), 0.859 and 0.927 (segment-level)]. CAC score correlated significantly with the presence of any CAV on both modalities. A diagnosis of rejection on biopsy did not correlate with any/significant CAV on DSCTCA or ICA. CONCLUSION: High sensitivity and NPV of DSCTCA in the evaluation of stenotic CAV suggests that it can be an accurate and non-invasive alternative to ICA for routine surveillance of HTX recipients. ADVANCES IN KNOWLEDGE: DSCTCA detects the stenotic CAV non-invasively in transplant recipients with high sensitivity, specificity and NPV when compared with catheter coronary angiography, at lower radiation doses. There is excellent agreement between CT angiography and catheter coronary angiography for detection of any CAV and significant CAV. A diagnosis of rejection on biopsy does not correlate with any/significant CAV on CT angiography or catheter angiography.

Greater Curvature, Centerline or Straightened Centerline Length - Which length is Most Accurate for Preprocedural Planning in Thoracic Endovascular Aortic Repair?

BACKGROUND: Automated centerline (CL) measurements have been conventionally used for stent-graft length estimation during thoracic endovascular aortic repair (TEVAR). The purpose of this study was to assess the accuracy of greater curvature length (GL), semiautomated CL and straightened centerline length (SCL) for preprocedural planning in TEVAR. METHODS: Immediate postprocedural CT Angiographies of 30 patients (22 males, age-49.2 ± 10.1years) who underwent TEVAR between 2015 and 2017 were retrospectively analyzed. CL, GL, SCL and the straightline length(SL) were measured between proximal and distal ends of the stent-graft and results were compared with the true length of the stent-graft (TL). Tortuosity index (TI = CL/SL) was calculated. RESULTS: GL (17.92 ± 4.78 cm) was the closest in predicting the TL (17.75 ± 4.29 cm) (P = 0.414) overall, as well as in both dissection and aneurysm subgroups (P= 0.9). There was a significant difference between CL (16.67 ± 4.07 cm) and TL (P< 0.0001) as well as between SCL (16.86 ± 4.16 cm) and TL (P= 0.001). These differences were greater in dissection subgroup than in the aneurysm group (P< 0.0001 and P= 0.03 for TL-CL and TL-SCL, respectively). The extent of mismatch between GL or CL and TL did not correlate with tortuosity, but the difference between TL and SCL had a significant positive correlation with tortuosity (r = 0.375, P= 0.04). TL-GL had a negative linear correlation with the stent-graft length (TL) in the dissection group (r = 0.50, P= 0.03). CONCLUSIONS: The greater curvature length predicts the actual total length of the deployed stent-graft more accurately than centerline or straightened centerline lengths. Hence, it should be used in planning for the length of stent-graft required for TEVAR.

Prevalence Rates of Congenital Coronary Anomalies and Coronary Variations in Adult Indian Population Using Dual-Source Computed Tomography Coronary Angiography: Analysis of Regional Distribution of Coronary Anomalies and the Need for Standardized Reporting Formats.

Background Congenital coronary artery anomalies (CCAA) are predominantly discovered as incidental findings on computed tomography coronary angiography (CTCA) of adults. They are rare but significant, considering their importance during endovascular or surgical interventions. This study describes the prevalence of CCAA and coronary variants (CV) in adults as identified by CTCA. Methods It is a retrospective evaluation of 7,694 CTCAs of adults performed in a tertiary care facility in North India. Results CCAA and CV were observed in a total of 9.6% of patients. The most common CV was myocardial bridging, observed in 7.1%. Anomalies of origin and course were detected in 2.3% of the patients. The frequency of these anomalies in the right coronary artery, left main, left circumflex artery, and the left anterior descending artery arteries were 1.06, 0.41, 0.03, and 0.38%, respectively. The single coronary pattern was seen in 0.05% and coronary artery fistulas in 0.03%. Scrutiny of data on Indian regional distribution revealed differing definitions and inclusion and exclusion criteria, making comparisons difficult, highlighting the need for uniform definitions as well as the need to adopt a standardized reporting template and format. Conclusion The prevalence of CCAA and CV is 9.6% in adult Indian patients undergoing CTCA. Prior knowledge of these anatomical finding can prevent a catastrophe during surgery or endovascular interventions. Hence, it is important that clinicians, as well as radiologists, are aware of these entities.

IVC filters - Indications for placement and retrieval trends- experience from a tertiary referral centre in India type of submission- full paper.

OBJECTIVES: There is wide variation in the practice of IVC filter placement and retrievals. We conducted a retrospective study to identify the trends in placement and retrievals of IVC filters in a tertiary referral centre in India. METHODS: The data of patients obtained from our hospital records, in whom IVC filter was placed between 2010 and 2018, were analysed for demographics, indications for placement of IVC filter, underlying comorbidities, characteristics of the filters as well as the retrieval rates. RESULTS: IVC filters were placed in 50 patients, and data was retrieved for 31 patients (mean - 51.24 years, 67.74% males). According to ACCP/AHA guidelines, 24 (77.42%) had an absolute indication for IVC filter. All 31 IVC filters were temporary, 23 (74.19%) of which were placed via femoral access. 29(93.55%) patients had infrarenal IVC filter placement. The average tilt at deployment was 3.71°, whereas it was 5.3° at retrieval. There were no periprocedural complications or filter migrations during placement or retrieval. Retrieval was attempted in 11 (35.48%) patients and was successful in 10. The mean indwelling time in this group was 158.55 days (range 55-366 days). CONCLUSION: Our study reveals low IVC filter implantation rates which are predominantly for absolute rather than relative indications. Though in sync with the worldwide trend, the poor retrieval rates reflect the urgent need for better patient and physician awareness. Periodic follow up is imperative to improve the IVC filter retrieval rate and to prevent complication rates.

Role of CMR feature-tracking derived left ventricular strain in predicting myocardial iron overload and assessing myocardial contractile dysfunction in patients with thalassemia major.

OBJECTIVE: Myocardial iron overload (MIO) in thalassemia major (TM) may cause subclinical left ventricular (LV) dysfunction which manifests with abnormal strain parameters before a decrease in ejection fraction (EF). Early detection of MIO using cardiovascular magnetic resonance (CMR)-T2* is vital. Our aim was to assess if CMR feature-tracking (FT) strain correlates with T2*, and whether it can identify early contractile dysfunction in patients with MIO but normal EF. METHODS: One hundred and four consecutive TM patients with LVEF > 55% on echocardiography were prospectively enrolled. Those fulfilling the inclusion criteria underwent CMR, with T2* being the gold standard for detecting MIO. Group 1 included patients without significant MIO (T2* > 20 ms) and group 2 with significant MIO (T2* < 20 ms). RESULTS: Eighty-six patients (mean age, 17.32 years, 59 males) underwent CMR. There were 68 (79.1%) patients in group 1 and 18 (20.9%) in group 2. Fourteen patients (16.3%) had mild-moderate MIO, and four (4.6%) had severe MIO. Patients in group 2 had significantly lower global radial strain (GRS). Global longitudinal strain (GLS) and global circumferential strain (GCS) did not correlate with T2*. T1 mapping values were significantly lower in patients with T2* < 10 ms than those with T2* of 10-20 ms; however, FT-strain values were not significantly different between these two groups. CONCLUSION: CMR-derived GRS, but not GLS and GCS, correlated with CMR T2*. GRS is significantly decreased in TM patients with MIO and normal EF when compared with those without. FT-strain may be a useful adjunct to CMR T2* and maybe an early marker of myocardial dysfunction in TM. KEY POINTS: • A global radial strain of < 29.3 derived from cardiac MRI could predict significant myocardial iron overload in patients with thalassemia, with a sensitivity of 76.5% and specificity of 66.7%. • Patients with any myocardial iron overload have significantly lower GRS, compared to those without, suggesting the ability of CMR strain to identify subtle myocardial contractile disturbances. • T1 and T2 mapping values are significantly lower in those with severe myocardial iron than those with mild-moderate iron, suggesting a potential role of T1 and T2 mapping in grading myocardial iron.

Spectrum of changes on cardiac magnetic resonance in repaired tetralogy of Fallot: Imaging according to surgical considerations.

Imaging of repaired tetralogy of Fallot (TOF) is one of the common indications for cardiac magnetic resonance (CMR) examinations. With advances in CMR imaging techniques like phase contrast imaging and functional imaging, it has superseded investigations like echocardiography for anatomical and functional assessment of the pathophysiological changes in repaired TOF. Common repair procedures for TOF include infundibulectomy, transannular patch repair and right ventricle to pulmonary artery (RV-PA) conduit. While each of these procedures cause dynamic changes in heart and pulmonary arteries resulting in some expected imaging findings, CMR also helps in diagnosing the complications associated with these repair procedures like pulmonary stenosis, right ventricular outflow tract aneurysm, pulmonary regurgitation, RV-PA conduit stenosis, tricuspid regurgitation, right ventricular failure, and residual ventricular septal defects. Hence, it is imperative for a radiologist to be familiar with the expected changes on CMR in repaired TOF along with some of the common complications that may be encountered on imaging in such patients.

Computed tomography imaging of complications in postoperative cyanotic congenital heart diseases - A pictorial essay.

Cross-sectional imaging plays an essential role in the diagnosis and management of various structural and functional changes that occur in the postoperative period after palliative or corrective surgical procedures performed for congenital heart diseases (CHD). Although echocardiography is the mainstay for the evaluation of CHD, it is limited by poor acoustic window post-surgery in addition to being operator dependent. Computed tomography (CT) allows for the comprehensive evaluation of the post-surgical anatomy and complications after repair for cyanotic CHD. Radiologists and cardiac imagers should be familiar with these expected changes after surgeries performed for various cyanotic CHDs, to obtain diagnostic quality cardiac CT images and to promptly recognise the abnormal post-operative appearances in this patient population. In this review, we describe the various CT features of complications that can be encountered after repair of cyanotic CHDs.

Advanced cardiac magnetic resonance imaging in takotsubo cardiomyopathy.

Takotsubo cardiomyopathy (TC) is a reversible condition in which there is transient left ventricular (LV) dysfunction characterised most commonly by basal hyperkinesis and mid-apical LV ballooning and hypokinesia. It is said to be triggered by stress and mimics, such as acute coronary syndrome (ACS) clinically. Diagnosis is usually suspected on echocardiography due to the characteristic contraction pattern in a patient with symptoms and signs of ACS but normal coronary arteries on catheter angiography. Cardiac magnetic resonance (CMR), with its latest advancements, is the diagnostic modality of choice for diagnosis, prognosis and follow-up of patients. The advances in CMR (including T1, T2, ECV mapping and threshold-based late gadolinium enhancement (LGE) measurements have revolutionised the role of CMR in tissue characterisation and prognostication in patients with TC. In this review, we highlight the current role of CMR in management of TC and enumerate the CMR findings in TC as well the current advances in the field of CMR, which could help in prognosticating these patients.

Successful surgical correction of tetralogy of fallot associated with anomalous left coronary artery connection to pulmonary artery.

Tetralogy of fallot is rarely associated with anomalous left coronary artery connection to main pulmonary artery. High index of suspicion is needed preoperatively to diagnose this association and treat successfully. We present a case of 9-year-old boy with the rare association of tetralogy of fallot and anomalous left coronary artery connection to pulmonary artery with a giant steal intercoronary collateral crossing right ventricular outflow tract who was treated successfully by single-stage surgical correction.

Double drainage of total anomalous pulmonary venous connection: An extremely rare variant.

We present a case of rare double drainage of total anomalous pulmonary venous connection, which was diagnosed on a dual-source CT scanner. This case also highlights the critical role of volume-rendered images for preoperative planning.