Insight into Noninvasive Radiological Modalities to Detect Heart Transplant Rejection

Purpose Patients with end-stage heart failure who remain symptomatic even with exemplary medical and device therapy are treated with heart transplantation. Multitudes of endeavor have been contrived during the last decennium in the field of noninvasive tests to rule out heart transplant rejection (HTR). In spite of having supportive literature, noninvasive imaging techniques lack acceptable documentation of clinical robustness, and endomyocardial biopsy (EMB) still remains the gold standard. The aim of this review is to shed light on the existing noninvasive radiological modalities to detect rejection among heart transplant recipients. Methods A comprehensive search was conducted for this review article on the basis of literature available including scientific databases of PubMed, Embase, and Google Scholar, using keywords of “Heart transplantation,” “Acute allograft rejection,” “Arrhythmias,” “Echocardiography,” “Speckle tracking echocardiography,” and “Cardiac magnetic resonance imaging” from inception until September 2020. Results After preliminary screening of the databases, details regarding existent noninvasive radiological modalities to detect HTR were gathered and compiled in this review article. Currently, deformation imaging using speckle tracking and T2 time using cardiac magnetic resonance imaging can serve as screening tools based on which further invasive investigations can be planned. Standardization of blood-based and imaging modalities as screening and possible diagnostic tools for rejection would have obvious clinical and financial benefits in the care of growing number of post heart transplant recipients in our country. Conclusion Diagnosis of allograft rejection in heart transplant recipients through noninvasive techniques is demanding. To unravel the potential of noninvasive radiological modalities that can serve as a standard-of-care test, a prospective multicentric study randomizing noninvasive modality as first strategy versus current EMB-based gold standard of care is the need of the hour.

Study on Anatomical Variations in Fissures of Lung by CT Scan

Introduction Refinements in the modern computed tomography (CT) imaging techniques have led to anatomical variations in the fissures of lung being diagnosed more frequently. So far, majority of the studies conducted are cadaveric. There is paucity of studies in this aspect based on chest CT images. Hence, we undertook this study to find the anatomical variations in the fissures. Prior detection of anatomical abnormalities is important to reduce postoperative complications in lung resection surgeries. Materials and Methods This was a cross-sectional study conducted over a period of 2 years. Data were collected from the patients who underwent CT scan thorax. Patients in whom normal anatomy of lung was distorted and cases where both lungs were not visualized completely were excluded from the study. All the CT images were reviewed by a single radiologist. The presence or absence of the normal and accessory pulmonary fissures, as well as the continuity of each fissure, was recorded by the radiologist. Data were compiled and analyzed. Results The study population consisted of 394 (70.4%) males and 166 (29.6%) females, totaling 560 cases. Fissural variations were detected in 22.9% (n = 128). Also, 17.5% (n = 98) fissural variations were seen in males and 5.4% (n = 30) fissural variations were seen in females. Further, 54.7% (n = 70) of variations were detected in the right lung and 45.3% (n = 58) in the left lung. The most common fissural variation noted was right incomplete oblique fissure with a frequency of 8.4% cases (n = 47). The most common accessory fissure detected was inferior accessory fissure. Total 22 cases were detected in both the lungs, 17 cases in male and 5 in female. Conclusion Anatomical variations in fissures were found to be more in the right lung than the left lung. Accessory fissures were detected in higher incidence on the right side.

Spinal Dysraphisms: A New Anatomical–Clinicoradiological Classification

Background Spinal dysraphisms refer to the congenital abnormalities of the spine and spinal cord due to aberrations in the processes of gastrulation, primary neurulation, and secondary neurulation. Embryology of many complex spinal dysraphisms are yet poorly understood and there is no agreeable anatomical–clinicoradiological classification with inclusion of recently documented and complex spinal dysraphisms. Aims and Objectives The main objective of this study was to review the imaging features of spinal dysraphisms with a better understanding of embryological abnormalities and propose a new classification inclusive of all complex and unusual dysraphisms based on anatomical and clinicoradiological correlation. Materials and Methods This was a retrospective single institutional observational study of 391 cases of spinal dysraphism for 10 years in our institution. Of 391 cases included in the study, 204 were males and 187 were females. Also, 123 cases belonged to the 0–6 months age group, 38 cases belonged to the 7–12 months age group, 156 belonged to the 1–5 years age group, 39 cases belonged to the 6–10 years age group, and 35 cases belonged to 10–20 years age group. Results An anatomical–clinicoradiological analysis of cases yielded a high proportion of cases of spinal lipomas, including lipomyeloceles and lipomyelomeningoceles (31.3%) and posterior myelomeningocele (14.2%). Anterior myelocoele (0.2%), sacral chordoma(0.2%), and intrasacral meningocele (0.2%) formed the least proportion of cases. A new classification was proposed based on the analysis of acquired data. Conclusion A structured approach in imaging spinal dysraphism is necessary for imaging evaluation in recent years. The proposed new classification based on clinicoradiological correlation and anatomic location is inclusive of unusual and complex dysraphisms.

Superdominant Right Coronary Artery with Absent Left Coronary Artery and Left Circumflex Artery with Anomalous Left Anterior Descending Artery

The occurrence of super-dominant “single coronary artery” is an extremely rare and seldom reported phenomenon. The heart is dependent on a single vessel which makes its occlusion, if present, catastrophic. Here, the authors present an extremely rare combination of superdominant right coronary artery coexisting with absent left coronary artery and left circumflex artery with abnormal origin of left anterior descending artery from right coronary sinus. Precise morphological and physiological knowledge and evaluation of these anomalies is a must for opting the best available therapeutic modality and better prognosis.

Biopsy with Side-Cutting Coaxial Needle—Knowing the “Cutting Length” and “Throw Length”

Image-guided Trucut biopsy is a well-established procedure. The length of the side notch in the stylet is the “cutting length,” which entraps the tissue sample and contributes to the yield. The total distance by which the inner stylet protrudes from the outer cannula with the cutting notch open is the “throw length.” It is inevitably longer than the cutting length does not add to the yield of the sample, but potentially to the complication of the procedure. The authors highlight the importance of knowing this distinction to minimize complications during the procedure.

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/m2. 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/m2 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.

Getting Vaccinated Helps: Prospective Study Reveals Lower CT Severity Scores amongst COVID Vaccine Recipients

Context Computerized tomography (CT) is an invaluable imaging investigation for evaluating COVID-19 disease. CT detects early changes of COVID-19 pneumonia and predicts the disease prognosis based on a semiquantitative 25-point CT severity score (CT-SS). India launched its vaccination drive in January 2021 with two different vaccines being approved by the government. These vaccines are believed to prevent the disease itself, in majority of the cases and at least decrease disease severity, in the rest. Aim This study aims to evaluate the CT-SS in vaccinated and non-vaccinated subjects who have been diagnosed with COVID-pneumonia or are COVID suspects. Subjects and Methods A total of 3,235 patients with typical COVID-19 related imaging findings on HRCT thorax were included in the study. These subjects were divided into three age categories, 18–44, 45–59 and ≥60 years. The CT severity scores were allotted by experienced radiologists. Medians of the scores in different age groups were compared amongst vaccinated and non-vaccinated individuals using the Kruskal–Wallis H test. A p-value < 0.05 was considered significant. All results were shown with 95% confidence interval. Results The difference in the medians amongst the vaccinated and non-vaccinated groups was significant, p-values being < 0.001 in all age categories. Conclusion The mean CT-SS was less in vaccinated subjects and the difference in median CT-SS amongst vaccinated and non-vaccinated individuals was statistically significant, thus sending an important message that it is mandatory for the population at large to get vaccinated to reduce infection rate/disease severity.

Selecting the Appropriate First-Line Strategy Based on Hyperdense Vessel Sign in Acute Ischemic Stroke Increases First Pass Recanalization: A Tertiary Center Experience

Background: The data pertaining to selecting an optimal first-line strategy (stent retriever [SR] vs. contact aspiration [CA]) based on noncontrast computed tomography (NCCT) in cases of acute ischemic stroke consequent to large vessel occlusion (LVO) is lacking. Aims: This article studies the influence of hyperdense vessel sign (HVS) in selecting optimal first-line strategy, with intention of increasing first-pass recanalization (FPR). Methods: Upfront approach at our center is SR technique with rescue therapy (CA) adoption consequent to three failed SR attempts to achieve successful recanalization. Data of patients with acute LVO who underwent mechanical thrombectomy from June 2017 to May 2020 was retrospectively analyzed. Patients were classified into HVS (+) and HVS (–) cohort. Rate of successful recanalization (first pass, early, and final) and efficacy of rescue therapy was assessed between the two cohorts. Results: Of 52 patients included, 28 and 24 were assigned to the HVS (+) and HVS (–) cohort, respectively. FPR was observed in 50% of HVS (+) and 20.9% of HVS (–) (p = 0.029). Early recanalization was documented in 64.2% of HVS (+) and 37.5% of HVS (–) (p = 0.054). Rescue therapy need was higher in patients not demonstrating HVS (p = 0.062). Successful recanalization was achieved with rescue therapy in 50% of HVS (–) group. Conclusion: A higher FPR is achievable following individualized first-pass strategy (based on NCCT appearance of clot), instead of a generalized SR first-pass approach. This CT imaging-based strategy is a step closer to achieving primary angiographic goal of FPR.

Soft-Tip Stylet and Saline Instillation Technique: Making Difficult Percutaneous CT-Guided Biopsies Possible

Finding a safe needle path during percutaneous computed tomography-guided biopsy is sometimes difficult due to concern for injuring a vital structure. Saline instillation technique has been used to displace the structure out of the way. Another useful tool is a soft-tip stylet. A soft-tip also referred as blunt-tip stylet for the introducer cannula is provided with some coaxial biopsy sets in additional to standard sharp-tip stylet. While the sharp-tip stylet is fitted with introducer cannula for piercing skin, muscle, and fascia, a soft-tip stylet may be used for avoiding injury to structures like vessels and bowel loops especially while advancing introducer cannula through fatty tissue. Additionally, it is also useful for avoiding injury to nerves and giving pleural anesthesia. Although its use has been described in medical literature, many radiologists are still not utilizing this tool to its full potential. In this educational exhibit, various applications of soft-tip stylet and saline instillation technique have been depicted using representative cases.

Radiation Protection in Interventional Radiology

There has been a rapid development in the field of interventional radiology over recent years, and this has led to a rapid increase in the number of interventional radiology procedures being performed. There is, however, a growing concern regarding radiation exposure to the patients and the operators during these procedures. In this article, we review the basics of radiation exposure, radiation protection techniques, radiation protection tools available to interventional radiologists, and radiation protection during pregnancy.