Israel Medical Association Journal

Background: Virtual autopsies by computer tomography (CT) or magnetic resonance imaging can be valuable in cases of unexplained infant death. The radiologist must be familiar with the normal appearance of all the segments of the thoracic aorta in normal and deceased children. A thorough review of the literature revealed no prior articles describing CT changes in the ascending aorta or the aortic arch in pediatric virtual autopsies.

Objectives: To compare the CT appearance of the thoracic aorta in deceased children and in those younger than 3 years of age.

Methods: Hospital registries were searched for cases of unexpected deaths in children younger than 3 years old, with a postmortem CT available, as well as for clinically indicated chest CT in children of the same age during a 5 year period. The ascending aorta (AA), aortic arch (arch), and the descending aorta (DA) diameters were measured. Student's t-tests and Mann–Whitney U-tests were used to compare the two groups.

Results: A total of 64 scans were reviewed: 35 postmortem and 29 performed on living patients. The differences in the diameter and the ratios of the diameter between the AA and the arch, as well as between the arch and the DA in the postmortem and living groups were statistically significant (P < 0.05).

Conclusions: On postmortem CT scans, we found focal tapering of the aortic caliber at the level of the arch between the origin of the brachiocephalic artery and left subclavian artery. This finding should not be misinterpreted as a hypoplastic aortic arch.

Background: While patients presenting to emergency departments (ER) with chest pain are increasingly managed in chest pain units (CPU) that utilize accelerated diagnostic protocols for risk stratification, such as single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI), data are lacking regarding the prognostic implications of mildly abnormal scans in this population.

Objectives: To evaluate the prognostic implications of mildly abnormal SPECT MPI results in patients with acute chest pain.

Methods: Of the 3753 chest pain patients admitted to the CPU at the Leviev Heart Center, Sheba Medical Center 1593 were further evaluated by SPECT MPI. Scans were scored by extent and severity of stress-induced perfusion defects, with 1221 patients classified as normal, 82 with myocardial infarction without ischemia, 236 with mild ischemia, and 54 with more than mild ischemia. Mild ischemia patients were further classified to those who did and did not undergo coronary angiography within 7 days.

Results: Mild ischemia patients who underwent coronary angiography were more likely to be male (92% vs. 81%, P = 0.01) and to have left anterior descending ischemia (67% vs. 42%, P = 0.004). After 50 months, these patients returned less often to the ER with chest pain (53% vs. 87%, P < 0.001) and had a lower combined endpoint of acute coronary syndrome and death (8% vs. 16%, P < 0.001).

Conclusions: Compared to patients with chronic stable angina, patients presenting with acute chest pain exhibiting mildly abnormal SPECT MPI findings should perhaps undergo a more aggressive diagnostic and therapeutic approach.

Background: Four-dimensional parathyroid computed tomography (4DCT) is a relatively new parathyroid imaging technique that provides functional and highly detailed anatomic information about parathyroid tumors.

Objective: To assess the accuracy of 4DCT for the preoperative localization of parathyroid adenomas (PTAs) in patients with biochemically confirmed primary hyperparathyroidism (PHPT) and a history of failed surgery or unsuccessful localization using ^99mTc-sestamibi scanning and ultrasonography.

Methods: Between January 2013 and January 2015, 55 patients with PHPT underwent 4DCT at Hillel Yaffe Medical Center, Hadera, Israel. An initial unenhanced scan was followed by an IV contrast injection of nonionic contrast material (120 ml of at 4 ml/s). Scanning was repeated 25, 60, and 90 seconds after the initiation of IV contrast administration. An experienced radiologist blinded to the earlier imaging results reviewed the 4DCT for the presence and location (quadrant) of the suspected PTAs. At the time of the study, 28 patients had undergone surgical exploration following 4DCT and we compared their scans with the surgical findings.

Results: 4DCT accurately localized 96% (27/28) of abnormal glands, all of which were hypervascular and showed characteristic rapid enhancement on 4DCT that could be distinguished from Level II lymph nodes. Surgery found hypovascular cystic PTA in one patient who produced a negative 4DCT scan. All patients had solitary PTAs. The scan at 90 seconds provided no additional information and was abandoned during the study.

Conclusions: 4DCT accurately localized hypervascular parathyroid lesions and distinguished them from other tissues. A three-phase scanning protocol may suffice.

Background: Silicone breast augmentation is a common cosmetic surgery. Previous case reports demonstrated lymphadenopathy in the presence of implant ruptures.

Objectives: To investigate the association between enlarged axillary lymph nodes and silicone implant ruptures as seen on breast magnetic resonance imaging (MRI).

Methods: Two groups were derived retrospectively from breast MRI reports in our institution for the period December 2011–May 2014. A search of our hospital records for "silicone" and "lymph node" was performed (group A), and the relationship between the presence of enlarged nodes and ruptures was evaluated. The prevalence of ruptures in the presence of nodes was calculated and the association between MRI imaging features and ruptures evaluated. A search for "silicone" and "implant rupture" was performed (group B) and, as for group A, the relationship between the presence of ruptures and nodes was evaluated and the prevalence of enlarged nodes in the presence of ruptures calculated.

Results: Group A comprised 45 women with enlarged nodes. Intracapsular ruptures were associated with nodes (P = 0.005), while extracapsular ruptures showed a trend of association with nodes (P = 0.08). The prevalence of ruptures in the presence of nodes was 31.4%. Nodes associated with ruptures showed a strong silicone signal (P = 0.008) and absent enhancement (P = 0.005). Group B comprised 73 women with ruptures. Enlarged nodes were associated with both intra- and extracapsular ruptures (P < 0.001 and P = 0.002 respectively). The prevalence of nodes in the presence of ruptures was 22.2%.

Conclusions: Enlarged axillary nodes were associated with ruptures in two groups of patients. This finding can guide clinical decisions when either enlarged nodes or ruptures are encountered in patients with silicone implants. The association between silicone lymphadenopathy and implant rupture raises concerns regarding the role of rupture in silicone-induced systemic disease.

 

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: Automated breast volumetric sonography (ABVS) is a new technology with various possible applications.

Objectives: To compare ABVS and breast magnetic resonance imaging (MRI) in the surveillance of women with BRCA1/2 gene mutation carriers.

Methods: We conducted a prospective study in Jewish female BRCA1/2 mutation carriers who underwent breast MRI and ABVS. The results of both exams performed 6 months apart or less, and relevant clinical data, were reviewed. The BIRADS results were divided into three subgroups according to subsequent expected management: BIRADS 1-2 (normal study), BIRADS 3 (probably benign finding), and BIRADS 4 and 5 (suspicious findings). BIRADS 0 and 6 scores were excluded from the study. Distribution of ABVS and MRI BIRADS scores were compared using McNemar's test, and concordance was calculated using the Cohen kappa test.

Results: Overall, 68 women, 40 BRCA1 and 28 BRCA2 mutation carriers, age range 26–69 (mean 44.55 ± 12.1 years), underwent 79 paired ABVS and MRI examinations. McNemar's test calculations showed no significant difference between MRI and ABVS BIRADS score distribution. Cohen’s kappa test resulted in k = 0.158, an agreement that can be described as only "slight agreement" between both modalities. Of 14 discordant cases there was one cancer, revealed by MRI and not by ABVS performed 6 months prior to MRI.

Conclusions: ABVS showed slight agreement with MRI in BRCA1/2 mutation carriers. These preliminary results on a small group of healthy high risk patients suggest that the diagnostic abilities of ABVS are inferior to MRI. Further studies encompassing larger groups are needed.

 

Background: Neurolathyrism is a toxic nutritional disorder caused by consumption of the grass pea, Lathyrus sativus. The disease, which manifests as an acute or insidiously evolving spastic paraparesis, continues to occur throughout Africa and Asia. Research on this disease is limited, and to our knowledge no imaging studies of patients with neurolathyrism have been published. 

Objectives: To better localize the site of damage in neurolathyrism using advanced imaging methods. 

Methods: Three male patients, immigrants from Ethiopia, were included in the study. All had a history of arrested spastic paraparesis that had evolved before their emigration from Ethiopia, and a past history of exposure to grass pea without any other cause. Functional magnetic resonance imaging (fMRI) included simple motor tasks to evaluate cortical motor areas. Anatomic scans included diffusion tensor imaging (DTI) to evaluate the corticospinal tracts.

Results: In all patients clear activation was found in motor regions and the patients’ activity pattern was qualitatively similar to that in control subjects. In one patient in whom clinical symptoms were asymmetric, an asymmetric activity pattern in M1 was identified. DTI analysis identified intact corticospinal tracts connecting the pons and the primary motor regions, similar to control subjects. 

Conclusions: Advanced neuroimaging clearly identified well-functioning motor regions and tracts in neurolathyrism patients, suggesting a spinal etiology.

 

Background: Although fat grafting is a common technique to repair defects after breast cancer reconstruction surgery and has a low complication rate, the relation between fat grafting and the risk of breast cancer is unknown. Clinical trials to investigate this connection can elucidate the benefits and potential risks of fat grafting in oncology patients.

Objectives:To establish an efficient experimental model, using magnetic resonance imaging (MRI) scans, for comparing different breast tumor study groups post-fat grafting. 

Methods: Breast tumor cells were injected into immunocompromised mice. After tumors formed they were removed. Liposuction was performed in a female human donor and fat was collected. Cells were extracted from the fat by enzymatic digestion. Immunocompromised mice were randomized into four groups: a preliminary experiment group and three equal groups according to the type of fat graft: (i) fresh fat enriched with adipose-derived mesenchymal stem cells (AdMSCs), (ii) fresh fat without cell enrichment, and (iii) no fat injected. Tumor volume was assessed by serial MRI scans. 

Results: The rate of tumor growth was higher in the enriched fat group compared to the non-enriched fat group. 

Conclusions: This experimental model is an effective measurable method, allowing future investigation of the effect of autologous fat on breast cancer.

 

The term non-radiographic axial spondyloarthritis (nrAxSpA) was coined for patients who have a clinical picture of ankylosing spondylitis (AS) but do not exhibit radiographic sacroiliitis. The ASAS classification criteria for nrAxSpA, ensuring the recruitment of homogenous study cohorts, were accepted in 2009, although the respective diagnostic criteria for daily clinical practice have not yet been developed. The clinical diagnosis should be based on the composite of clinical symptoms and signs of the disease, HLA B27 status, and magnetic resonance imaging (MRI) of sacroiliac joints. Notably, a negative MRI or HLA B27 does not exclude the diagnosis in patients with a high clinical suspicion for nrAxSpA. The prevalence of nrAxSpA is similar to that of AS, but the former has a higher female preponderance. The rate of progression of nrAxSpA to the radiographic stage of disease (AS) ranges from 10% to 20% over 2 years. Current treatment strategies for nrAxSpA are the same as for AS and include non-steroidal anti-inflammatory drugs and inhibitors of tumor necrosis factor-alpha. While this review summarizes the current achievements in the field of nrAxSpA, further understanding of the epidemiology and natural history of the disease and, particularly, mechanisms of inflammation and subsequent new bone formation is essential for the development of new treatment strategies for nrAxSpA patients. 

Background: Plain abdominal radiographs are still performed as a first imaging examination to evaluate abdominal pain in the emergency department (ED), despite uncertainty regarding their utility.

Objectives: To describe the frequency and outcomes of the use of plain abdominal radiographs in the diagnosis of patients presenting with acute non-traumatic abdominal pain in the ED of a medical center. 

Methods: We retrospectively reviewed the records of patients presenting to the ED with acute abdominal pain during a 6 month period. Further imaging (computed tomography, ultrasonography), when performed, was compared with the abdominal radiography. 

Results: Of 573 consecutive patients, 300 (52%) underwent abdominal radiography. Findings were normal in 88% (n=264), non-specific in 7.3% (n=22), and abnormal in 4.7% (n=14). For those with normal results, no further imaging was ordered for 43% (114/264). Of the 57% (150/264) who had follow-up imaging, 65% (98/150) showed abnormal findings. In 9 (3%) of the 300 patients, abdominal radiography identified bowel perforations and obstructions, and treatment was provided without the need for further radiologic examination.

Conclusions: The use of plain abdominal radiography is still common despite the high rate of false positive results. Efforts are needed to decrease the indiscriminate use of radiography in patients presenting with abdominal symptoms.