Cardiac MRI in restrictive cardiomyopathy

A. Gupta, G. Singh Gulati, S. Seth, S. Sharma — 2011-10-05

Restrictive cardiomyopathy (RCM) is a specific group of heart muscle disorders characterized by inadequate ventricular relaxation during diastole. This leads to diastolic dysfunction with relative preservation of systolic function. Although short axis systolic function is usually preserved in RCM, the long axis systolic function may be severely impaired. Confirmation of diagnosis and information regarding aetiology, extent of myocardial damage, and response to treatment requires imaging. Importantly, differentiation from constrictive pericarditis (CCP) is needed, as only the latter is managed surgically. Echocardiography is the initial cardiac imaging technique but cannot reliably suggest a tissue diagnosis; although recent advances, especially tissue Doppler imaging and spectral tracking, have improved its ability to differentiate RCM from CCP. Cardiac catheterization is the reference standard, but is invasive, two-dimensional, and does not aid myocardial characterization. Cardiac magnetic resonance (CMR) is a versatile technique providing anatomical, morphological and functional information. In recent years, it has been shown to provide important information regarding disease mechanisms, and also been found useful to guide treatment, assess its outcome and predict patient prognosis. This review describes the CMR features of RCM, appearances in various diseases, its overall role in patient management, and how it compares with other imaging techniques.

Three-dimensional isotropic T2-weighted cervical MRI at 3T: Comparison with two-dimensional T2-weighted sequences

J.W. Kwon, Y.C. Yoon, S.-H. Choi — 2011-12-06

Aim: To compare three-dimensional (3D) isotropic T2-weighted magnetic resonance imaging (MRI) sequences and reformation with two-dimensional (2D) T2-weighted sequences regarding image quality of the cervical spine at 3T.Materials and methods: A phantom study was performed using a water-filled cylinder. The signal-to-noise and image homogeneity were evaluated. Fourteen (n=14) volunteers were examined at 3T using 3D isotropic T2-weighted sagittal and conventional 2D T2-weighted sagittal, axial, and oblique sagittal MRI. Multiplanar reformation (MPR) of the 3D T2-weighted sagittal dataset was performed simultaneously with image evaluation. In addition to artefact assessment, the visibility of anatomical structures in the 3D and 2D sequences was qualitatively assessed by two radiologists independently. Cohen’s kappa and Wilcoxon signed rank test were used for the statistical analysis.Result: The 3D isotropic T2-weighted sequence resulted in the highest signal-to-noise ratio (SNR) and lowest non-uniformity (NU) among the sequences in the phantom study. Quantitative evaluation revealed lower NU values of the cerebrospinal fluid (CSF) and muscles in 2D T2-weighted sagittal sequences compared to the 3D volume isotropic turbo spin-echo acquisition (VISTA) sequence. The other NU values revealed no statistically significant difference between the 2D turbo spin-echo (TSE) and 3D VISTA sequences (0.059

An observational study to evaluate the performance of units using two radiographers to read screening mammograms

R.L. Bennett, S.J. Sellars, R.G. Blanks, S.M. Moss — 2011-11-10

Aim: To examine the performance of screening units in which a proportion of mammograms were double read using “non-discordant radiographer only (double) reading” (NDROR).Materials and methods: NDROR was used by seven pilot units between 2006 and 2009, and six further units in 2009 only. There were 51 comparison units. Screening performance outcome measures were calculated, and logistic regression was used to compare performance between the pilot and comparison units.Results: Phase 1 pilot units read between on average 15 and 48% of mammograms per year using NDROR between 2006 and 2009 (median, 33%) and in 2009, phase 2 pilot units used NDROR to read between 4 and 77% of mammograms (median, 34%). The results showed an increase in recall rates in the phase 1 pilot units relative to the comparison units at both prevalent and incident screens (adjusted OR 1.09, 95% CI 1.05, 1.14; and adjusted OR 1.10, 95% CI 1.07, 1.14, respectively). There were also increases in the phase 2 pilot units relative to the comparison units; adjusted OR 1.08 (95% 1.00, 1.17) at prevalent screens, and adjusted OR 1.07 (95% CI 1.02, 1.14) at incident screens. There was no evidence to suggest a difference in cancer-detection rates between the pilot units and the comparison units.Conclusions: Evidence from the present study suggests that recall rates may increase as a result of units using radiographers to double read a proportion of their mammograms. However, there is little evidence to suggest that NDROR, as practiced by the pilot units in the present study, is likely to have major impacts on performance in the UK National Health Service Breast Screening Programme (NHSBSP), particularly if it is fully supported and closely monitored (particularly recall rates).

Percutaneous radiofrequency ablation using internally cooled wet electrodes for treatment of colorectal liver metastases

H.M. Yoon, J.H. Kim, Y.M. Shin, H.J. Won, P.N. Kim — 2011-09-12

Aim: To evaluate the efficacy and safety of internally cooled wet (ICW) electrodes, which provide interstitial infusion of saline and intra-electrode cooling simultaneously, in the percutaneous radiofrequency ablation (RFA) of liver metastases from colorectal cancer.Materials and methods: From February 2008 to October 2010, 27 patients with 35 hepatic metastatic lesions (mean size 1.99cm; range 0.7–3.8cm) underwent RFA using ICW electrodes. Of these 35 tumours, 32 had diameters ≤3cm, and three had diameters of 3–4cm. Moreover, 18 tumours were non-subcapsular and 17 were subcapsular.Results: No patients (0%) had major complications after RFA. During follow-up (median 27 months; range 4.5–36 months), 14 of the 35 treated lesions (40%) showed local tumour progression. The local tumour progression-free survival rates at 1 and 3 years were 73 and 56%, respectively. The local tumour progression-free survival period was significantly longer in patients with tumours ≤2cm than >2cm (p<0.001), but did not differ significantly between patients with non-subcapsular and subcapsular tumours (p=0.454). The overall 1 and 3 year survival rates after RFA were 100 and 77%, respectively.Conclusions: Percutaneous RFA using ICW electrodes is safe and technically feasible for the treatment of liver metastases from colorectal cancer. It provides effective local tumour control with low complication rates and reduced number of needle placements.

The use of imaging in patients post breast reconstruction

Y.T. Sim, J.C. Litherland — 2011-09-12

Aim: To evaluate the usefulness of mammographic surveillance for asymptomatic patients and as a problem-solving tool in symptomatic patients with reconstructed breasts.Materials and methods: The imaging records over 4 years identified 227 patients with a history of breast reconstruction post-mastectomy due to cancer. Clinical and imaging records were reviewed to evaluate the use of imaging in the follow-up management of these patients.Results: Records showed that 116 (51%) of the patients identified underwent surveillance mammography of the reconstructed breast, in which one recurrent cancer was detected in an autologous tissue flap reconstruction (0.86% detection rate of non-palpable recurrent cancer), with a recall rate of 4%. One other patient had interval recurrence diagnosed following presentation with pain. Mammography of the contralateral breast only was performed in 111 patients. Fifty-four patients (24%) presented on 78 occasions with symptoms relating to the breast reconstructions, most commonly lump or swelling. Half of these patient episodes subsequently found no significant abnormality, and a further 29% had fat necrosis revealed on imaging. Four recurrent cancers were diagnosed.Conclusion: There is insufficient evidence for recommending routine surveillance mammography for non-palpable recurrent cancer in the reconstructed breasts. Ultrasound and mammography are useful imaging techniques in the assessment of reconstructed breasts in the symptomatic setting. Fat necrosis is the most common benign finding on mammograms of reconstructed breasts, both in the surveillance and symptomatic groups.

Postoperative omental infarction following colonic resection

S.F. Kerr, R. Hyland, E. Rowbotham, A.G. Chalmers — 2011-09-15

Aim: To illustrate the computed tomography (CT) appearances and natural history of postoperative omental infarction following colonic resection and to highlight the important clinical implications of this radiological diagnosis.Materials and methods: Over a 3 year period, 15 patients with a history of colonic resection were identified as having a CT diagnosis of postoperative omental infarction. Relevant clinical and pathological data were retrospectively collected from the institution’s electronic patient records system and all relevant imaging was reviewed, including serial CT images in 10 patients.Results: A diagnosis of postoperative omental infarction was made in symptomatic and asymptomatic patients who had undergone open or laparoscopic colonic resection for benign or malignant disease. CT appearances ranged from diffuse omental stranding to discrete masses, which typically appeared within weeks of surgery and could persist for years. In four (36%) of the patients with colorectal cancer, the CT appearances raised concern for recurrent malignancy, but percutaneous biopsy and/or serial CT allowed a confident diagnosis of omental infarction to be made. Although most cases were self-limiting, three (20%) cases were complicated by secondary infection and required radiological or surgical intervention.Conclusion: Postoperative omental infarction is an under-recognized complication of colonic resection. It has the potential to mimic recurrent malignancy and may require radiological or surgical intervention for secondary infection.

Staging of laryngeal carcinoma: Comparison of high-frequency sonography and contrast-enhanced computed tomography

Q. Hu, F. Luo, S.Y. Zhu, Z. Zhang, Y.P. Mao, X. Hui Guan — 2011-09-28

Aim: To evaluate the accuracy of high-frequency sonography on pretherapeutic T-staging in patients with laryngeal carcinoma.Materials and methods: Thirty-six consecutive patients with laryngeal carcinoma undergoing surgical resection were included in this study. All patients underwent ultrasonographic examination and contrast-enhanced computed tomography before surgery. These imaging interpretations were evaluated independently and then compared with the reference of postoperative pathological examination. McNemar’s test was used for comparing the data obtained separately from ultrasonography and computed tomography.Results: There was one T2 stage tumour of an aryepiglottic fold undetected by sonography. Sonography failed to stage five tumours correctly; the T-staging accuracy was 83.3%. Contrast-enhanced computed tomography failed to stage four patients correctly; the T-staging accuracy was 88.8%. There was no difference between the pretherapeutic staging accuracy of ultrasonography and contrast-enhanced computed tomography (p=0.735).Conclusion: Ultrasonography has a reliable pretherapeutic staging accuracy of laryngeal carcinoma. It can be a non-invasive complementary technique for pretherapeutic staging of laryngeal carcinoma.

Hepatocellular carcinoma in patients with chronic liver disease: A comparison of gadoxetic acid-enhanced MRI and multiphasic MDCT

2011-09-15

Aim: To compare the diagnostic performances of gadoxetic acid-enhanced magnetic resonance imaging (MRI) and multiphasic multidetector computed tomography (MDCT) in the detection of hepatocellular carcinoma (HCC) in patients with chronic liver disease.Materials and methods: Institutional review board approval was obtained for this study and informed consent was obtained from all patients. Fifty-one patients (43 men, eight women; age range 32–80 years) with 73 HCCs underwent gadoxetic acid-enhanced MRI and multiphasic MDCT. Two readers independently analysed each image in three separate reading sessions. The alternative free-response receiver operating characteristic (AFROC) method was used to analyse the diagnostic accuracy. Positive and negative predictive values and sensitivity were evaluated.Results: A total of 73 HCCs were detected in 51 patients. Although not significant (p>0.05), the areas under the receiver operating characteristic curves were 0.877 and 0.850 for MDCT, 0.918 and 0.911 for dynamic MRI, and 0.905 and 0.918 for combined interpretation of dynamic and hepatobiliary phase MR images. Differences in sensitivity, specificity, and positive and negative predictive values between the readers were not statistically significant (p>0.05). Combined interpretation of dynamic and hepatobiliary phase MRI images was more useful than MDCT in the detection of HCC lesions ≤1cm in diameter for one reader (p=0.043).Conclusion: Gadoxetic acid-enhanced MRI and MDCT show similar diagnostic performances for the detection of HCC in patients with chronic liver disease. However, the combined interpretation of dynamic and hepatobiliary phase MRI images may improve diagnostic accuracy in the detection of HCC lesions ≤1cm in diameter.

Tumour heterogeneity in oesophageal cancer assessed by CT texture analysis: Preliminary evidence of an association with tumour metabolism, stage, and survival

B. Ganeshan, K. Skogen, I. Pressney, D. Coutroubis, K. Miles — 2011-09-26

Aim: To undertake a pilot study assessing whether tumour heterogeneity evaluated using computed tomography texture analysis (CTTA) has the potential to provide a marker of tumour aggression and prognosis in oesophageal cancer.Materials and methods: In 21 patients, unenhanced CT images of the primary oesophageal lesion obtained using positron-emission tomography (PET)-CT examinations underwent CTTA. CTTA was carried out using a software algorithm that selectively filters and extracts textures at different anatomical scales between filter values 1.0 (fine detail) and 2.5 (coarse features) with quantification as entropy and uniformity (measures image heterogeneity). Texture parameters were correlated with average tumour 2-[18F]-fluoro-2-deoxy-d-glucose (FDG) uptake [standardized uptake values (SUVmean and SUVmax)] and clinical staging as determined by endoscopic ultrasound (nodal involvement) and PET-CT (distant metastases). The relationship between tumour stage, FDG uptake, and texture with survival was assessed using Kaplan–Meier analysis.Results: Tumour heterogeneity correlated with SUVmax and SUVmean. The closest correlations were found for SUVmean measured as uniformity and entropy with coarse filtration (r=–0.754, p<0.0001; and r=0.748, p=0.0001 respectively). Heterogeneity was also significantly greater in patients with clinical stage III or IV for filter values between 1.0 and 2.0 (maximum difference at filter value 1.5: entropy: p=0.027; uniformity p=0.032). The median (range) survival was 21 (4–34) months. Tumour heterogeneity assessed by CTTA (coarse uniformity) was an independent predictor of survival [odds ratio (OR)=4.45 (95% CI: 1.08, 18.37); p=0.039].Conclusion: CTTA assessment of tumour heterogeneity has the potential to identify oesophageal cancers with adverse biological features and provide a prognostic indicator of survival.

Congenital anomalies of the inferior vena cava

M. Malaki, A.P. Willis, R.G. Jones — 2011-11-09

Congenital anomalies of the inferior vena cava (IVC) and its tributaries are increasingly recognized in asymptomatic patients due to the more frequent use of cross-sectional imaging and computed tomography (CT) in particular. IVC development is a complex process involving formation of anastomoses between three pairs of embryonic veins in the 4th to 8th week of gestation. Various permutations occur in the basic venous plan of the abdomen and pelvis resulting in variants such as isolated left IVC, double IVC, and retroaortic left renal vein. The majority of these anomalies are asymptomatic but occasionally present clinically with thromboembolic complications. However, awareness of their existence is important to avoid important diagnostic pitfalls and in preoperative surgical and interventional radiological planning.

Masses and disease entities of the external auditory canal: Radiological and clinical correlation

2011-10-24

A wide spectrum of disease entities can affect the external auditory canal (EAC). This review describes the normal anatomy of the EAC. Congenital abnormalities, infections, neoplasms, and miscellaneous conditions, such as cholesteatoma and acquired stenosis, are shown with reference to clinical relevance and management. Cases have been histologically confirmed, where relevant. The EAC is frequently imaged — for example, on cross-sectional imaging of the brain — and this review should stimulate radiologists to include it as an important area for review.

Preliminary experience of percutaneous intralesional bleomycin injection for the treatment of orbital lymphatic–venous malformation refractory to surgery

C.-Y. Shen, M.-C. Wu, Y.-S. Tyan, C.-H. Ou, T.-Y. Chen, H.-F. Wong — 2011-10-24

Vascular disorders of the orbit are divided into vascular malformations and vascular tumours. Orbital lymphatic–venous malformations (LVMs) are rare low-flow vascular malformations that occur in infants and children, but occasionally, orbital LVMs may first manifest with a visible mass in an adult, as a result of a haemorrhagic or infectious process. Surgical resection has been considered the standard treatment for orbital LVM but sometimes results in surgical complications and postoperative recurrence.

Dynamic four-dimensional 320 section CT and carpal bone injury — A description of a novel technique to diagnose scapholunate instability

D. Halpenny, K. Courtney, W.C. Torreggiani — 2011-12-05

Scapholunate interosseous ligament injury is a common sequel of wrist trauma. Early and accurate diagnosis of this injury is vital to avoid long-term disability. Static instability is generally easy to identify, but the dynamic form of scapholunate ligament injury may be difficult to diagnose because stationary imaging techniques such as plain radiography are often normal. Four dimensional (4D), 320 section computed tomography (CT) allows the radiologist to assess the articulation of the carpal bones in a dynamic fashion. Images are acquired during wrist motion and image analysis is performed using three-dimensional (3D) and multiplanar reformations, which can then be viewed as cine-loops to allow a functional assessment of wrist motion. We present the case of a 52-year-old man who despite normal radiographs was suspected to have scapholunate ligamentous injury. Dynamic CT images demonstrated an increase in the scapholunate distance to 6 mm (it had been normal on static images). He was diagnosed with dynamic scapholunate instability.

Renal inflammatory myofibroblastic tumour with multiple calcifications

L. Wen, Q.-R. Sun, X.-W. Diao, J.-P. Luo, Q.-C. Zhang, D. Zhang — 2011-11-28

Inflammatory myofibroblastic tumours (IMFTs) or inflammatory pseudotumours are relatively rare pathological entities composed of myofibroblasts and accompanying inflammatory infiltrates, which can occur in almost any location. Kidney involvement is extremely rare. Few papers have detailed the imaging features of renal IMFTs. We report the characteristics and imaging features of a case of renal IMFT, and provide a review of the literature.

The challenge of assessing reader performance in mammography

P.C. Brennan, B.P. Soh — 2011-11-28

Sir — I read with interest the paper of Cornford et al. recently published in the Journal. It focuses on the important issue of screening mammography and the impact on performance of volume of cases read. The authors argue that their data do not provide any evidence to suggest a relationship between years of film reading and film-reading performance, but one must be careful that this is not interpreted as evidence for the absence of a relationship. Their result could be as a result of insufficient statistical power due to low reader numbers, a limitation acknowledged by the author.

A re-look at an old disease: A multimodality review on gout [Clin Radiol 2011; 66(10) 984–992]

S. Dhanda, P. Jagmohan, S.T. Quek — 2011-11-11

The authors would like to draw your attention to the fact that the name of the third author was incorrectly arranged as Q. S. Tian. The correct details, which should be used for citation purposes, are given above.

Notices

2012-02-01

Clinical Radiology

Contents