Increasing radiation exposure from computed tomography in liver transplant recipients over time.

OBJECTIVES: To evaluate changes in radiation exposure from computed tomography (CT) among patients undergoing liver transplantation in our unit over a 10-year period. METHODS: We evaluated 134 elective patients, without hepatocellular carcinoma or cholangiocarcinoma who underwent transplantation in 2007-2008 and 2017-2018. CT scans performed in our hospital up to 2 years pre transplant and 1 year post transplant were evaluated. RESULTS: There was an increase in mean estimated effective radiation dose per patient in 2017-2018 compared to 2007-2008 (77.8 mSv ± 6.2 vs 56.7 mSv ± 5.9, p < 0.05). This change was mainly due to an increased number of pre-transplant CT scans per patient (2.9 ± 0.3 vs 1.4 ± 0.14, p = 0.0001). High radiation dose scan protocols were more frequently used in 2017-2018, with 4-phase liver CT accounting for a larger proportion of scans both pre-transplant (61% vs 43%, p = 0.004) and post-transplant (29% vs 13%, p = 0.002). A greater proportion of patients were exposed to > 100 mSv of ionising radiation in the 2017-2018 patients (29% vs 11%, p < 0.01). These figures are likely to be a significant under-estimate as they exclude other imaging modalities and CT scans performed at other institutions. CONCLUSION: Radiation exposure from diagnostic imaging has increased among liver transplant recipients at our institution over the last decade. This appears to be due to an increase in the number of CT scans performed, and a shift towards higher dose scan protocols.

The Value of Isosulfan Blue Dye in Addition to Isotope Scanning in the Identification of the Sentinel Lymph Node in Breast Cancer Patients With a Positive Lymphoscintigraphy: A Randomized Controlled Trial (ISRCTN98849733).

BACKGROUND: Sentinel lymph node biopsy (SLNB) has become the gold standard for axillary staging. Debate remains as to the optimal method of SLN detection. OBJECTIVES: Determine whether patients undergoing an SLNB required the addition of isosulfan blue dye to radioisotope when an SLN was identified on a preoperative lymphoscintigram. METHODS: A prospective randomized controlled trial comparing the combination of radioisotope and blue dye versus radioisotope alone was performed between March 2010 and September 2012. The trial protocol was registered with Current Controlled Trials. Women with clinically and radiologically node-negative breast cancer with a positive preoperative lymphoscintigram were eligible for inclusion. RESULTS: A total of 667 patients were included in the analysis with 342 patients receiving the combination (blue dye and radioisotope) and 325 patients receiving radioisotope alone. The groups were evenly matched both demographically and pathologically. The mean age was 48 years (48.3 vs 47.7 years; P = 0.47), the mean tumour size was 24.2 mm (24.3 mm vs 24.1 mm; P = 0.7) and there was no statistically significant difference in the grade of the tumors between the 2 groups (P = 0.58). There was no difference in the identification rate, nor was that in the number of nodes retrieved between the 2 groups (P = 0.30). There was no difference in the number of positive lymph nodes that were identified between the 2 groups (23.8% vs 22.1%; P = 0.64). CONCLUSIONS: This study failed to demonstrate an advantage with the addition of isosulfan blue dye to radioisotope in the identification of the SLN in the presence of a positive preoperative lymphoscintigram.

Hepatocellular carcinoma: illustrated guide to systematic radiologic diagnosis and staging according to guidelines of the American Association for the Study of Liver Diseases.

Hepatocellular carcinoma is a malignancy that predominantly occurs in the setting of cirrhosis. Its incidence is rising worldwide. Hepatocellular carcinoma differs from most malignancies because it is commonly diagnosed on the basis of imaging features alone, without histologic confirmation. The guidelines from the American Association for the Study of Liver Diseases (AASLD) are a leading statement for the diagnosis and staging of hepatocellular carcinoma, and they have recently been updated, incorporating several important changes. AASLD advocates the use of the Barcelona Clinic Liver Cancer (BCLC) staging system, which combines validated imaging and clinical predictors of survival to determine stage and which links staging with treatment options. Each stage of the BCLC system is outlined clearly, with emphasis on case examples. Focal liver lesions identified at ultrasonographic surveillance in patients with cirrhosis require further investigation. Lesions larger than 1 cm should be assessed with multiphasic computed tomography or magnetic resonance imaging. Use of proper equipment and protocols is essential. Lesions larger than 1 cm can be diagnosed as hepatocellular carcinoma from a single study if the characteristic dynamic perfusion pattern of arterial hyperenhancement and venous or delayed phase washout is demonstrated. If the imaging characteristics of hepatocellular carcinoma are not met, the alternate modality should be performed. Biopsy should be used if neither modality is diagnostic of hepatocellular carcinoma. Once the diagnosis has been made, the cancer should be assigned a BCLC stage, which will help determine suitable treatment options. Radiologists require a systematic approach to diagnose and stage hepatocellular carcinoma with appropriate accuracy and precision.

Initial impact of a systematic multidisciplinary approach on the management of patients with gastroenteropancreatic neuroendocrine tumor.

According to the international guidelines, a multidisciplinary approach is currently advised for the optimal care of patients with a gastroenteropancreatic neuroendocrine tumor (GEP NET). In our institution (tertiary care center), a systematic multidisciplinary approach was established in May 2007. In this study, we have aimed to assess the initial impact of establishing a systematic multidisciplinary approach to the management of GEP NET patients. We have collected and compared the biochemical, imaging, and pathological data and the therapeutic strategies in GEP NET patients diagnosed, treated, or followed-up from January 1993 to April 2007 versus GEP NET patients attending our institution after the multidisciplinary approach starting, from May 2007 to October 2008. Data of 91 patients before and 42 patients after the establishment of the multidisciplinary approach (total: 133 consecutive GEP NET patients) have been finally collected and analyzed. Before the establishment of the multidisciplinary approach, a lack of consistency in the biochemical, imaging, and pathological findings before treatment initiation as well as during follow-up of GEP NET patients was identified. These inconsistencies have been reduced by the systematic multidisciplinary approach. In addition, the therapeutic management of GEP NET patients has been altered by the multidisciplinary approach and became more consistent with recommended guidelines. We think that a systematic multidisciplinary approach significantly impacts on GEP NET patient care and should be established in all centers dealing with these tumors.

Staging of gastroenteropancreatic neuroendocrine tumors: how we do it based on an evidence-based approach.

In contrast to other common types of malignant tumors, the vast majority of gastroenteropancreatic neuroendocrine tumors are well differentiated and slowly growing with only a minority showing aggressive behavior. It is important to accurately stage patients radiologically so the correct treatment can be implemented and to improve prognosis. In this article, we critically appraise the current literature in an effort to establish the current role of radiologic imaging in the staging of neuroendocrine tumors. We also discuss our protocol for staging neuroendocrine tumors.

Metastatic chordoma detected by endobronchial ultrasound-guided transbronchial needle aspiration.

Chordomas are rare, slow-growing malignant bone tumours arising from cellular remnants of the notochord. These tumours are locally invasive but have also a metastastic potential.Chordomas are characterized by the presence of physaliferous cells in a myxofibrillary stromal background. In cytological aspirates, these characteristic cells are usually absent, revealing only clusters of cells with varying degrees of vacuolation. This makes definitive diagnosis of chordoma difficult as the tumor can mimic other myxoid neoplasms including renal cell carcinomas and well-differentiated chondrosarcomas. In such situations, a confident diagnosis of chordoma requires comparison with histology of the primary tumor.We describe the first case of metastatic chordoma diagnosed by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA).

An 18FDG-PET/CT finding of a mediastinal abscess.

A 66-year-old man with left pyriform fossa squamous cell carcinoma (T2N0) was treated with chemoradiation. Nine months later, an emergency tracheostomy was performed for respiratory distress. Contrast-enhanced neck and thorax CT demonstrated a right pyriform mass. FDG-PET/CT showed linear increased uptake extending superiorly from the tracheostomy to the right Eustachian tube and inferiorly to the posterior mediastinum. Postmortem examination confirmed a 7 × 2.2 cm abscess extending from the right parapharyngeal, peritracheal, and prevertebral structures to the mediastinum.

A predictive model of suitability for minimally invasive parathyroid surgery in the treatment of primary hyperparathyroidism [corrected].

BACKGROUND: Improved preoperative localizing studies have facilitated minimally invasive approaches in the treatment of primary hyperparathyroidism (PHPT). Success depends on the ability to reliably select patients who have PHPT due to single-gland disease. We propose a model encompassing preoperative clinical, biochemical, and imaging studies to predict a patient's suitability for minimally invasive surgery. METHODS: For the purposes of the present study, 180 consecutive patients were included for analysis. A 5-variable model based on preoperative ionized serum calcium (>1.4 mmol/l), intact parathyroid hormone level (≥ 2 times the upper limit of normal), positive sestamibi scan for a single affected gland, positive ultrasound scan for a single gland, and concordance between the two imaging modalities for single-gland disease at a similar location was employed, where a score of 1 was allocated for each variable present. RESULTS: Of the 180 patients, 62 (34%) underwent bilateral exploration, 63 (36%) underwent unilateral exploration, and 55 (30%) underwent minimally invasive parathyroidectomy. The results showed that 92% had single-gland disease, 3% had double adenomas, and 5% had hyperplasia. Biochemical cure was achieved in 98.9%. Mean follow-up was 153 days (range: 80-342 days). With the predictive scoring model, a score of ≥ 3 had a positive predictive value of 100% for single-gland disease. CONCLUSIONS: A scoring model encompassing preoperative biochemical and imaging data can be successfully employed to predict suitability for minimally invasive surgery in the majority of patients with single-gland disease.

Pulmonary CT angiography protocol adapted to the hemodynamic effects of pregnancy.

OBJECTIVE: The purpose of this study was to compare the image quality of a standard pulmonary CT angiography (CTA) protocol with a pulmonary CTA protocol optimized for use in pregnant patients with suspected pulmonary embolism (PE). MATERIALS AND METHODS: Forty-five consecutive pregnant patients with suspected PE were retrospectively included in the study: 25 patients (group A) underwent standard-protocol pulmonary CTA and 20 patients (group B) were imaged using a protocol modified for pregnancy. The modified protocol used a shallow inspiration breath-hold and a high concentration, high rate of injection, and high volume of contrast material. Objective image quality and subjective image quality were evaluated by measuring pulmonary arterial enhancement, determining whether there was transient interruption of the contrast bolus by unopacified blood from the inferior vena cava (IVC), and assessing diagnostic adequacy. RESULTS: Objective and subjective image quality were significantly better for group B-that is, for the group who underwent the CTA protocol optimized for pregnancy. Mean pulmonary arterial enhancement and the percentage of studies characterized as adequate for diagnosis were higher in group B than in group A: 321 ± 148 HU (SD) versus 178 ± 67 HU (p = 0.0001) and 90% versus 64% (p = 0.05), respectively. Transient interruption of contrast material by unopacified blood from the IVC was observed more frequently in group A (39%) than in group B (10%) (p = 0.05). CONCLUSION: A pulmonary CTA protocol optimized for pregnancy significantly improved image quality by increasing pulmonary arterial opacification, improving diagnostic adequacy, and decreasing transient interruption of the contrast bolus by unopacified blood from the IVC.

Intramedullary spinal cord metastasis from colonic carcinoma presenting as Brown-Séquard syndrome: a case report.

INTRODUCTION: Intramedullary spinal cord metastasis is very rare. The majority are discovered incidentally during autopsy. Most symptomatic patients present with rapidly progressive neurological deficits and require immediate examination. Few patients demonstrate features of Brown-Séquard syndrome. Radiotherapy is the gold-standard of therapy for Intramedullary spinal cord metastasis. The overall prognosis is poor and the mortality rate is very high. We present what is, to the best of our knowledge, the first case of Intramedullary spinal cord metastasis of colorectal carcinoma presenting as Brown-Séquard syndrome. CASE PRESENTATION: We present the case of a 71-year-old Caucasian man with colonic adenocarcinoma who developed Intramedullary spinal cord metastasis and showed features of Brown-Séquard syndrome, which is an uncommon presentation of Intramedullary spinal cord metastasis. CONCLUSION: This patient had an Intramedullary spinal cord metastasis, a rare form of metastatic disease, secondary to colonic carcinoma. The metastasis manifested clinically as Brown-Séquard syndrome, itself a very uncommon condition. This syndrome is rarely caused by intramedullary tumors. This unique case has particular interest in medicine, especially for the specialties of medical, surgical and radiation oncology. We hope that it will add more information to the literature about these entities.

Whole body imaging in the abdominal cancer patient: pitfalls of PET-CT.

Proper interpretation of PET-CT images requires knowledge of the normal physiological distribution of the tracer, frequently encountered physiological variants, and benign pathological causes of FDG uptake that can be confused with a malignant neoplasm. In addition, not all malignant processes are associated with avid tracer uptake. A basic knowledge of the technique of image acquisition is also required to avoid pitfalls such as misregistration of anatomical and scintigraphic data. This article reviews these potential pitfalls as they apply to the abdomen and pelvis of patients with cancer.

Pulmonary embolism in pregnancy: comparison of pulmonary CT angiography and lung scintigraphy.

OBJECTIVE: The purpose of this study was to retrospectively compare the diagnostic adequacy of lung scintigraphy with that of pulmonary CT angiography (CTA) in the care of pregnant patients with suspected pulmonary embolism. MATERIALS AND METHODS: Patient characteristics, radiology report content, additional imaging performed, final diagnosis, and diagnostic adequacy were recorded for pregnant patients consecutively referred for lung scintigraphy or pulmonary CTA according to physician preference. Measurements of pulmonary arterial enhancement were performed on all pulmonary CTA images of pregnant patients. Lung scintigraphy and pulmonary CTA studies deemed inadequate for diagnosis at the time of image acquisition were further assessed, and the cause of diagnostic inadequacy was determined. The relative contribution of the inferior vena cava to the right side of the heart was measured on nondiagnostic CTA images and compared with that on CTA images of age-matched nonpregnant women, who were the controls. RESULTS: Twenty-eight pulmonary CTA examinations were performed on 25 pregnant patients, and 25 lung scintigraphic studies were performed on 25 pregnant patients. Lung scintigraphy was more frequently adequate for diagnosis than was pulmonary CTA (4% vs 35.7%) (p = 0.0058). Pulmonary CTA had a higher diagnostic inadequacy rate among pregnant than nonpregnant women (35.7% vs 2.1%) (p < 0.001). Transient interruption of contrast material by unopacified blood from the inferior vena cava was identified in eight of 10 nondiagnostic pulmonary CTA studies. CONCLUSION: We found that lung scintigraphy was more reliable than pulmonary CTA in pregnant patients. Transient interruption of contrast material by unopacified blood from the inferior vena cava is a common finding at pulmonary CTA of pregnant patients.

FDG PET in preoperative assessment of colorectal liver metastases combining "evidence-based practice" and "technology assessment" methods to develop departmental imaging protocols: should FDG PET be routinely used in the preoperative assessment of patients with colorectal liver metastases?

In today's environment of progressively evolving and expensive imaging modalities, radiologists are asked to justify the use of resources to patients, referring physicians, hospital management, and third party payers. With this aim, the radiologist may use "top-down" or "bottom-up" "evidence-based practice" (EBP) techniques. "Top-down" suggests that the practitioner should wait until a higher authority, external to their practice, generates a solution to practice dilemmas (e.g., National Institute for Health and Clinical Excellence [NICE] guidelines). "Bottom-up" however, is based on the theory that the ordinary practitioner is best served by a decentralized approach to problem solving that is internal to their practice. The technology assessment framework modeled by Mackenzie and Dixon comprehensively assesses the effects of imaging using levels of efficacy including diagnostic performance, diagnostic impact, and therapeutic impact, impact on health and cost effectiveness. In this article, we describe how issues regarding new imaging modalities in ordinary radiology practice can be addressed by using stepwise "bottom-up" EBP techniques combined with the technology assessment framework. We also detail how EBP techniques form an integral part of practice-based learning among radiology residents as part of noninterpretive residency training. The following clinical scenario is used: your hospital's chief hepatobiliary surgeon writes to your department regarding the lack of access to 18-fluoro-2-deoxy-D-glucose positron emission tomography in the preoperative assessment of patients with colorectal cancer liver metastases under consideration for hepatic resection. How would you approach this problem? Here is how we would do it.