Israel Medical Association Journal

Background: Medical imaging and the resultant ionizing radiation exposure is a public concern due to the possible risk of cancer induction.

Objectives: To assess the accuracy of ultra-low-dose (ULD) chest computed tomography (CT) with denoising versus normal dose (ND) chest CT using the Lung CT Screening Reporting and Data System (Lung-RADS).

Methods: This prospective single-arm study comprised 52 patients who underwent both ND and ULD scans. Subsequently AI-based denoising methods were applied to produce a denoised ULD scan. Two chest radiologists independently and blindly assessed all scans. Each scan was assigned a Lung-RADS score and grouped as 1 + 2 and 3 + 4.

Results: The study included 30 men (58%) and 22 women (42%); mean age 69.9 ± 9 years (range 54–88). ULD scan radiation exposure was comparable on average to 3.6–4.8% of the radiation depending on patient BMI. Denoising increased signal-to-noise ratio by 27.7%. We found substantial inter-observer agreement in all scans for Lung-RADS grouping. Denoised scans performed better than ULD scans when negative likelihood ratio (LR-) was calculated (0.04–-0.08 vs. 0.08–0.12). Other than radiation changes, diameter measurement differences and part-solid nodules misclassification as a ground-glass nodule caused most Lung-RADS miscategorization.

Conclusions: When assessing asymptomatic patients for pulmonary nodules, finding a negative screen using ULD CT with denoising makes it highly unlikely for a patient to have a pulmonary nodule that requires aggressive investigation. Future studies of this technique should include larger cohorts and be considered for lung cancer screening as radiation exposure is radically reduced.

Background: Correct diagnosis of cardiac masses is a challenge in clinical practice. Accurate identification and differentiation between cardiac thrombi and tumors is crucial because prognosis and appropriate clinical management vary substantially.

Objectives: To evaluate the diagnostic performances of cardiac magnetic resonance imaging (CMR) in differentiating between cardiac thrombi and tumors.

Methods: A retrospective review of a prospectively maintained database of all CMR scans was performed to distinguish between cardiac thrombi and tumors during a 10 year period in a single academic referral center (2004–2013). Cases with an available standard of reference for a definite diagnosis were included. Correlation of CMR differentiation between thrombi and tumors with an available standard of reference was performed. Sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), and accuracy were reported.

Results: In this study, 101 consecutive patients underwent CMR for suspicious cardiac masses documented on transthoracic or transesophageal echocardiography. CMR did not detect any cardiac pathology in 17% (17/101), including detection of anatomical variants and benign findings in 18% (15/84). Of the remaining 69 patients, CMR diagnosis was correlated with histopathologic result in 74% (51/69), imaging follow-up in 22% (15/69), and a definite CMR diagnosis (lipoma) in 4% (3/69). For tumors, diagnostic accuracy, sensitivity, specificity, PPV, and NPV were 96.6%, 98%, 86.6%, 96.2%, and 96.6%, respectively. For thrombi, the results were 93.6%, 86.7%, 98.04%, 92.9%, and 97%, respectively.

Conclusions: CMR is highly accurate in differentiating cardiac thrombi from tumors and should be included in the routine evaluation of cardiac masses.

Background: Pregnant women with acute abdominal pain pose a diagnostic challenge. Delay in diagnosis may result in significant risk to the fetus. The preferred diagnostic modality is magnetic resonance imaging (MRI), since ultrasonography is often inconclusive, and computed tomography (CT) would expose the fetus to ionizing radiation

Objectives: To describe the process in setting up an around-the-clock MRI service for diagnosing appendicitis in pregnant women and to evaluate the contribution of abdominal MR in the diagnosis of acute appendicitis.

Methods: We conducted a retrospective study of consecutive pregnant women presenting with acute abdominal pain over a 6 year period who underwent MRI studies. A workflow that involved a multidisciplinary team was developed. A modified MRI protocol adapted to pregnancy was formulated. Data regarding patients' characteristics, imaging reports and outcome were collected retrospectively. 

Results: 49 pregnant women with suspected appendicitis were enrolled. Physical examination was followed by ultrasound: when positive, the patients were referred for MR scan or surgery treatment; when the ultrasound was inconclusive, MR scan was performed. In 88% of women appendicitis was ruled out and surgery was prevented. MRI diagnosed all cases with acute appendicitis and one case was inconclusive. The overall statistical performance of the study shows a negative predictive value of 100% (95%CI 91.9–100%) and positive predictive value of 83.3% (95%CI 35.9–99.6%).

Conclusions: Creation of an around-the-clock imaging service using abdominal MRI with the establishment of a workflow chart using a dedicated MR protocol is feasible. It provides a safe way to rule out appendicitis and to avoid futile surgery in pregnant women.

Background: Trans-catheter valve implantation (TAVI) is a non-surgical alternative for patients with severe aortic stenosis (AS). Pre-procedural computed tomography angiography (CTA) allows accurate “road mapping,” aortic annulus sizing and the detection of incidental findings.

Objectives: To document the prevalence of non-valvular extra-cardiac findings on CTA prior to TAVI and the impact of these findings on the procedure.  

Methods: Ninety AS patients underwent CTA as part of pre-TAVI planning. Scans extended from the clavicles to the groin. Non-vascular non-valvular findings were documented and graded as follows: (A) significant findings causing TAVI cancellation or postponement, (B) significant findings leading to a change in the TAVI procedure approach, (C) non-significant findings not affecting the TAVI procedure. 

Results: TAVI was planned for 90 patients; their average age was 80.2 ± 7.5 years, 53% were females. Overall, non-valvular cardiac, extra-cardiac and extra-vascular significant and non-significant incidental findings were documented in 97% of scans (87/90). Significant pathologies causing TAVI cancellation or postponement (category A) were documented in 8%. Significant findings affecting the TAVI procedure (category B) were found in 16% of patients. 

Conclusions: Pre-TAVI CTA detected non-valvular extra-vascular pathologies leading to procedure cancellation/postponement or procedure modification in 8% and 16%, respectively. Comprehensive CTA evaluation that acknowledges the importance of such findings is of major importance since it might alter the TAVI procedure or even render it inappropriate. 

 

Abstract

Background: Only a few studies have compared the accuracy of magnetic resonance enterography (MRE) and computed tomography enterography (CTE) in the diagnosis of Crohn's disease and its complications.

Objectives: To compare the sensitivity of MRE and CTE analysis in their ability to detect, sign-by-sign, 10 classical imaging signs of Crohn's disease.

Methods: The study group comprised 42 biopsy-proven Crohn's disease patients who underwent both CTE and MRE within an average period of 6 weeks. Agreement between the two modalities in detecting the 10 most significant radiological signs of CD was evaluated using the Kappa index. The sensitivity of MRE and CTE was calculated using a standard of reference composed of all the findings seen by CTE and/or MRE. We analyzed MRE and CTE sensitivity separately in two groups, according to the time interval between the examinations.

Results: Agreement between CTE and MRE was more than 70% in 8 of the 10 signs: mural thickening, phlegmon, stenosis, skip lesions, mucosal stratification, fistula, abscess, and creeping fat. The Kappa level of agreement values for CTE versus MRE varied between substantial for phlegmon and skip lesions; moderate for fistula, creeping fat, abscess and mural thickening; and fair for stenosis and dilatation. CTE detected more findings than MRE, except for creeping fat and fistula. There was no significant difference in the sensitivity of CTE and MRE in the two groups defined by the time interval (time < 1.5 and time > 1.5 months) except for detection of dilatation.

Conclusions: Almost all imaging signs of Crohn's disease were detected equally well by both modalities regardless of the time interval between examinations. We therefore consider MRE to be reliable for imaging and follow-up in patients with Crohn's disease who may need recurrent imaging.

Objectives: To assess the role of electrocardiography-gated CT-angiography (ECG-CTA) in the routine evaluation of CHD in neonates and infants particularly for the assessment of extracardiac findings.

Methods: The study cohort comprised 40 consecutive patients who underwent trans-thoracic echocardiography (TTE) and ECG-CTA. TTE and ECG-gated CTA findings regarding extracardiac vascular structures, coronary arteries and airways were compared with surgical or cardiac catheterization findings. Scans were evaluated for image quality using a subjective visual scale (from 1 to 4). Effective radiation dose was calculated for each scan.

Results: Median age was 28 ± 88 days and mean weight 3.7 ± 1.5 kg. Diagnostic quality was good or excellent (visual image score 3–4) in 39 of 40 scans (97.5%). ECG-CTA provided important additional information regarding extracardiac vascular structures and airway anatomy, complementing TTE in 75.6% of scans. Overall sensitivity of ECG-gated CTA for detecting extracardiac findings as compared with operative and cardiac catheterization findings was 97.6%. The calculated mean effective radiation dose was 1.4 ± 0.07 mSv (range 1.014–2.3 mSv).

Conclusions: ECG-CTA is an accurate modality for demonstrating extracardiac structures in complex CHD. It provides important complementary information to TTE regarding extracardiac vascular structures and coronary artery anatomy. This modality may obviate the need for invasive cardiac catheterization, thus exposing the patient to a much lower radiation dose. 

Objectives: To present the feasibility and safety of DSMR in Israel.

Methods: Thirty patients with suspected or known CAD were studied. DSMR images were acquired during short breath-holds in three short axis views and four-, two-, and three-chamber views. Patients were examined at rest and during a standard dobutamine-atropine protocol. Regional wall motion was assessed in a 16-segment model and the image quality was evaluated using a four-point scale for the visibility of the endocardial border.

Results: In 28 patients (93.4%) DSMR was successfully performed and completed within an average of 55 ± 6 minutes. One patient could not be examined because of claustrophobia and another patient, who was on beta-blockers, did not reach the target heart rate. Image quality was excellent and there was no difference between the rest and stress images in short axis (3.91 ± 0.29 vs. 3.88 ± 0.34, P = 0.13, respectively) and long axis (3.83 ± 0.38 vs. 3.70 ± 0.49, P = 0.09, respectively) views. Segmental intra-observer agreement for wall motion contractility at rest and stress cine images was almost perfect (κ = 0.88, 95% confidence interval = 0.93–0.84, and κ = 0.82, 95% CI = 0.88–0.76) respectively. No serious side effects were observed during DSMR.

Conclusion: The present study confirms the feasibility, safety and excellent image quality of DSMR for the diagnosis of coronary artery diseases.

Objective: To determine whether there are such ethnic differences and what, if anything, is their clinical relevance.

Methods: Of the 3663 enrolled infants born at the Hillel Yaffe Medical Center during the 12 month study period, 55 were of Ethiopian origin and their medical records were retrospectively surveyed. The retrieved data were compared with those of 167 randomly selected non-Ethiopian newborns (controls). Exclusion criteria were preterm delivery, admission to the neonatal intensive care unit, and congenital birth defects.

Results: Newborn infants of Ethiopian origin spit up 57% more than control infants. The difference in the number of spit ups was more obvious when only the infants who spit up were compared (2.3 ± 1.7 Ethiopian newborns vs. 1.5 ± 0.9 controls, P = 0.002), although the percentage of infants who spit up was the same in the two groups. There was no difference in weight gain, days of hospitalization, bilirubin levels or nutrition type between the groups.

Conclusions: Infants of Ethiopian origin spit up more than the control newborn infants of non-Ethiopian origin, while other clinical parameters were similar. In the absence of other pathological signs, spitting up is a non-relevant clinical condition.

Background: Coronary computed tomography angiography (CCTA) is an established modality for ruling out coronary artery disease. However, it has been suggested that CCTA may be a source of non-negligible radiation exposure.

Objectives: To evaluate the potential degradation in coronary image quality when using prospective gated (PG) CCTA as compared with retrospective gated (RG) CCTA in chest pain evaluation.

Methods: The study cohort comprised 216 patients: 108 consecutive patients in the PG CCTA arm and 108 patients matched for age, gender and heart rate in the RG CCTA arm. Scans were performed using a 64-slice multidetector CT scanner. All 15 coronary segments were evaluated subjectively for image quality using a 5-point visual scale. Dose-length product was recorded for each patient and the effective radiation dose was calculated

Results: The PG CCTA technique demonstrated a significantly higher incidence of step artifacts in the middle and distal right coronary artery, the distal left anterior descending artery, the second diagonal, the distal left circumflex artery, and the second marginal branches. Nevertheless, the diagnostic performance of these scans was not adversely affected. The mean effective radiation doses were 3.8 ± 0.9 mSv vs.17.2 ± 3 mSv for PG CCTA and RG CCTA, respectively (P < 0.0001).

Conclusions: Artifacts caused by the PG CCTA technique (64 MDCT) scanners tended to appear in specific coronary segments but did not impair the overall diagnostic quality of CCTA and there was a marked reduction in radiation exposure. We conclude that 64-slice PG CCTA is suitable for clinical use, especially for acute chest pain "fast track" evaluation targeted at relatively young subjects in a chest pain unit.
 

Background: Assessment of small intestinal disease remains a challenge for both clinicians and radiologists. Modern magnetic resonance enterography (MRE) is a non-radiation modality that can demonstrate both intestinal wall pathologies and extraluminal lesions.

Objectives: To analyze the results of 213 MRE scans performed since 2005.

Methods: Consecutive MRE[1] scans performed in our academic medical center between December 2005 and November 2009 were reviewed for patients' demographic data, indications for the examination, and main imaging findings. The imaging findings recorded were mural changes and intraluminal filling defects; there were also mesenteric findings and extraintestinal inflammatory findings.

Results: During the study period 213 MRE scans were performed; 70% of them for proven or suspected Crohn's disease (CD) of the small bowel. Another indication was small bowel neoplasm (6% of the scans). Bowel wall thickening and enhancement were seen in 60% and 53% of MRE scans, respectively. Mesenteric involvement was found in 52% of the patients. Incidental extraintestinal findings were detected in 17% of the scans. In 22% of the scans there was no pathological finding.

Conclusions: Our 4-year clinical experience with MRE shows that this non-invasive and non-radiating modality is a powerful technique for evaluation and long-term follow-up of small bowel pathologies. The most common clinical indication was the evaluation of Crohn’s disease. With physicians’ increased awareness, the future use of MRE in the evaluation of other small bowel pathologies such as neoplasm and celiac disease will increase.

Background: Many patients present to the emergency department with chest pain. While in most of them chest pain represents a benign complaint, in some patients it underlies a life-threatening illness.

Objectives: To assess the routine evaluation of patients presenting to the ED[1] with acute chest pain via the utilization of a cardiologist-based chest pain unit using different non-invasive imaging modalities.

Methods: We evaluated the records of 1055 consecutive patients who presented to the ED with complaints of chest pain and were admitted to the CPU[2]. After an observation period and according to the decision of the attending cardiologist, patients underwent myocardial perfusion scintigraphy, multidetector computed tomography, or stress echocardiography.

Results: The CPU attending cardiologist did not prescribe non-invasive evaluation for 108 of the 1055 patients, who were either admitted (58 patients) or discharged (50 patients) after an observation period. Of those remaining, 445 patients underwent MDCT[3], 444 MPS[4], and 58 stress echocardiography. Altogether, 907 patients (86%) were discharged from the CPU. During an average period of 236 ± 223 days, 25 patients (3.1%) were readmitted due to chest pain of suspected cardiac origin, and only 8 patients (0.9%) suffered a major adverse cardiovascular event.

Conclusions: Utilization of the CPU enabled a rapid and thorough evaluation of the patients’ primary complaint, thereby reducing hospitalization costs and occupancy on the one hand and avoiding misdiagnosis in discharged patients on the other.
 

[1] ED = emergency department

[2] CPU = chest pain unit

[3] MDCT = multidetector computed tomography

[4] MPS = myocardial perfusion scintigraphy