Comparison between nonspecific and necrosis-avid gadolinium contrast agents in vascular disrupting agent-induced necrosis of rodent tumors at 3.0T

OBJECTIVE

: To compare a commercial contrast agent (CA) Dotarem and a necrosis-avid CA (NACA) for their ability to evaluate the therapeutic necrosis with a vascular disrupting agent (VDA) on magnetic resonance imaging in rodent liver tumors to determine which could better correlate with the histopathologic outcome.

METHODS

: After the VDA treatment, 16 rats with 32 liver rhabdomyosarcomas were randomized into Dotarem and NACA groups (n = 8 per group) for both interindividual and intraindividual comparisons. T2-weighted imaging, T1-weighted imaging (T1WI), contrast-enhanced T1-weighted imaging (CE-T1WI), and diffusion-weighted imaging were performed at baseline, after VDA treatment and CA injections. The enhancing efficacy of CAs at immediate and delayed enhancement on CE-T1WI in viable tumor and necrosis was compared. Tumor necrosis ratios calculated from NACA and Dotarem were compared and correlated with gold-standard histopathology.

RESULTS

: On the immediate CE-T1WI, viable tumor was enhanced by either CA. On the delayed CE-T1WI at 30 minutes, both CAs failed to demarcate viable tumor from necrosis. At 24 hours post-NACA, the necrosis was clearly distinguished from viable tumor and thus derived necrosis ratio matched that from histopathology (P = 0.99); necrosis ratio from Dotarem was significantly lower than that from NACA and histopathology (P < 0.05, both), with a higher correlation of NACA than that of Dotarem with histopathology (r = 0.99 vs. r = 0.82).

CONCLUSIONS

: NACA better evaluated VDA-induced tumor necrosis than nonspecific CA on T1WI in tumor models of rat liver. NACA showed a closer correlation with histopathology than nonspecific CA for the delineation of true necrosis. Delayed enhancement on T1WI with nonspecific CA is not suitable for the assessment of VDA-induced tumor necrosis.

Review of dynamic contrast-enhanced ultrasound guidance in ablation therapy for hepatocellular carcinoma

Local ablative techniques-percutaneous ethanol injection, microwave coagulation therapy and radiofrequency ablation (RFA)-have been developed to treat unresectable hepatocellular carcinoma (HCC). The success rate of percutaneous ablation therapy for HCC depends on correct targeting of the tumor via an imaging technique. However, probe insertion often is not completely accurate for small HCC nodules, which are poorly defined on conventional B-mode ultrasound (US) alone. Thus, multiple sessions of ablation therapy are frequently required in difficult cases. By means of two breakthroughs in US technology, harmonic imaging and the development of second-generation contrast agents, dynamic contrast-enhanced harmonic US imaging with an intravenous contrast agent can depict tumor vascularity sensitively and accurately, and is able to evaluate small hypervascular HCCs even when B-mode US cannot adequately characterize the tumors. Therefore, dynamic contrast-enhanced US can facilitate RFA electrode placement in hypervascular HCC, which is poorly depicted by B-mode US. The use of dynamic contrast-enhanced US guidance in ablation therapy for liver cancer is an efficient approach. Here, we present an overview of the current status of dynamic contrast-enhanced US-guided ablation therapy, and summarize the current indications and outcomes of reported clinical use in comparison with that of other modalities.

Contrast-enhanced ultrasound for the diagnosis of hepatic adenoma

Nine hepatic adenomas (HA) diagnosed by contrast-enhanced ultrasound (CEUS) among 123 liver lesions (89 patients) were evaluated retrospectively; five were confirmed through pathological diagnosis. Time-intensity curves (TIC), contrast medium arriving time (AT), peak time (PT) and retrogression time (RT) for HA were compared with 30 hepatocellular carcinomas (HCC) and six focal nodular hyperplasias (FNH). Significant differences existed between HA and poorly-differentiated HCC in AT, PT and RT, and between HA and well-differentiated HCC in AT. Differential diagnosis between HA and FNH was determined only through their different perfusion and arterial morphological features: HA showed typical perfusion characteristic of 'fast-in, slow-out', with a centripetal or mixed-filling pattern in the arterial phase, while FNH showed a centrifugal filling pattern. In conclusion, CEUS was helpful for identifying HA but it may be relatively difficult to distinguish between HA and some well-differentiated HCC or FNH.

Usefulness of chest ultrasonography in detecting pulmonary embolism in patient with chronic obstructive pulmonary disease and chronic renal failure: a case report

We describe the case of a 75-year-old man affected by a chronic obstructive pulmonary disease and chronic renal failure admitted to our emergency department for dyspnea and interscapular stabbing pain. Chest radiography showed diffuse parenchymal consolidation in the lower right lung with bronchiectasis, but the treatment for infection disease did not improve the clinical conditions of the patient. According to Wells score indicating an intermediate risk for pulmonary embolism, we performed a chest ultrasonography that showed ultrasonographic patterns of thromboembolism. Because the presence of chronic renal failure limited the execution of a helical computed tomographic pulmonary angiography, a pulmonary scintigraphy was performed confirming the diagnosis of pulmonary embolism. Our case suggested that chest ultrasonography can be a valuable tool for early detection of pulmonary embolism and to establish immediately an appropriate therapy.

Lyso-thermosensitive liposomal doxorubicin: an adjuvant to increase the cure rate of radiofrequency ablation in liver cancer

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer death worldwide. No more than 30% of HCC patients are considered suitable for curative treatment because of tumor size and severity of liver impairment, among other factors. Radiofrequency ablation (RFA) monotherapy can cure small (<3 cm) HCC tumors. An adjuvant that interacts synergistically with RFA might enable curative therapy for many HCC patients with lesions >3 cm. Lyso-thermosensitive liposomal doxorubicin (LTLD) consists of the heat-enhanced cytotoxic doxorubicin within a heat-activated liposome. LTLD is infused intravenously prior to RFA. When heated to >39.5°C, LTLD releases doxorubicin in high concentrations into the tumor and the tumor margins. The RFA plus LTLD combination has shown a statistically significant dose-response effect for time to treatment failure in a Phase I trial in which most subjects (62.5%) had tumors >3 cm. RFA plus LTLD is currently being evaluated in a 600-patient randomized, double-blind, dummy-controlled trial.

Magnetic resonance enterography findings of chronic radiation enteritis

The diagnosis of chronic radiation enteritis (CRE) is considerably challenging both for clinicians and radiologists. The aim of this study was to evaluate the role of magnetic resonance enterography (MRE) in the diagnosis of CRE. To the best of our knowledge, there are no reports on the role of MRE in the diagnosis of CRE specifically. In this report, we present MRE findings of 4 patients with CRE. The most important factors in CRE diagnosis are the clinical findings and medical history, but focal abnormal bowel loop in the region of a known radiation field is the most important information. This abnormal loop is generally located in the distal ileum as present in our patients. Other associated findings helpful for the diagnosis are small bowel thickening, contrast material enhancement in a long segment, mesenteric stranding and luminal narrowing. MRE can be sufficient and useful in the diagnosis of CRE and for treatment planning, especially in patients with significant comorbidities who have had radiotherapy in the past. Adding MRE into the diagnostic algorithm can be helpful in post-radiotherapy patients with acute/subacute gastrointestinal symptoms.

Peripheral doses in patients undergoing Cyberknife treatment for intracranial lesions. A single centre experience

Background

Stereotactic radiosurgery/radiotherapy procedures are known to deliver a very high dose per fraction, and thus, the corresponding peripheral dose could be a limiting factor for the long term surviving patients. The aim of this clinical study was to measure the peripheral dose delivered to patients undergoing intracranial Cyberknife treatment, using the MOSFET dosimeters. The influence of the supplemental shielding, the number of monitor units and the collimator size to the peripheral dose were investigated.

Methods

MOSFET dosimeters were placed in preselected anatomical regions of the patient undergoing Cyberknife treatment, namely the thyroid gland, the nipple, the umbilicus and the pubic symphysis.

Results

The mean peripheral doses before the supplemental shielding was added to the Cyberknife unit were 51.79 cGy, 13.31 cGy and 10.07 cGy while after the shielding upgrade they were 38.40 cGy, 10.94 cGy, and 8.69 cGy, in the thyroid gland, the umbilicus and the pubic symphysis, respectively. The increase of the collimator size corresponds to an increase of the PD and becomes less significant at larger distances, indicating that at these distances the PD is predominate due to the head leakage and collimator scatter.

Conclusion

Weighting the effect of the number of monitor units and the collimator size can be effectively used during the optimization procedure in order to choose the most suitable treatment plan that will deliver the maximum dose to the tumor, while being compatible with the dose constraints for the surrounding organs at risk. Attention is required in defining the thyroid gland as a structure of avoidance in the treatment plan especially in patients with benign diseases.

[Emergency radiology: what clinicians expect from radiologists]

We review the relations between the radiology department and the clinicians that attend emergency patients, complementing our opinions with a survey conducted in the emergency departments of hospitals in the autonomous region of Madrid. A dedicated emergency radiology section is present in 63.2% of hospitals. Radiologists are readily available to consult in the emergency department in 100%. Radiologists are involved in the initial workup in 61% of hospitals, in follow-up in 22.3%, and in both the initial workup and follow-up in 16.7%. At least one common protocol is shared by radiologists and emergency clinicians in 73.7% of hospitals. Radiologists participate in deciding which imaging tests to perform in 78.9% of hospitals. Radiologists provide a written report of the examination in 83.3% of cases. Continual assessment of the relations between the emergency department and the radiology department will enable us to understand their dynamics and to know what aspects can be improved.

Ultrasonography in the management of the airway

In this study, it is described how to use ultrasonography (US) for real-time imaging of the airway from the mouth, over pharynx, larynx, and trachea to the peripheral alveoli, and how to use this in airway management. US has several advantages for imaging of the airway - it is safe, quick, repeatable, portable, widely available, and it must be used dynamically for maximum benefit in airway management, in direct conjunction with the airway management, i.e. immediately before, during, and after airway interventions. US can be used for direct observation of whether the tube enters the trachea or the esophagus by placing the ultrasound probe transversely on the neck at the level of the suprasternal notch during intubation, thus confirming intubation without the need for ventilation or circulation. US can be applied before anesthesia induction and diagnose several conditions that affect airway management, but it remains to be determined in which kind of patients the predictive value of such an examination is high enough to recommend this as a routine approach to airway management planning. US can identify the croicothyroid membrane prior to management of a difficult airway, can confirm ventilation by observing lung sliding bilaterally and should be the first diagnostic approach when a pneumothorax is suspected intraoperatively or during initial trauma-evaluation. US can improve percutaneous dilatational tracheostomy by identifying the correct tracheal-ring interspace, avoiding blood vessels and determining the depth from the skin to the tracheal wall.

Air in the heart: what should one do?

Air embolism is a serious and frequently underrecognized complication of vascular access device placement. Improper precautions during vascular catheter insertion result in inadvertent introduction of air into the vasculature. Systemic embolization into the cerebral, pulmonary, and coronary circulations can be catastrophic. We present a case of intracardiac air embolism after placement of a central venous catheter managed conservatively.

High-sensitivity in vivo THz transmission imaging of early human breast cancer in a subcutaneous xenograft mouse model

We performed in vivo THz transmission imaging study on a subcutaneous xenograft mouse model for early human breast cancer detection. With a THz-fiber-scanning transmission imaging system, we continuously monitored the growth of human breast cancer in mice. Our in vivo study not only indicates that THz transmission imaging can distinguish cancer from the surrounding fatty tissue, but also with a high sensitivity. Our in vivo study on the subcutaneous xenograft mouse model will encourage broad and further investigations for future early cancer screening by using THz imaging system.

Investigation of direct production of 68Ga with low energy multiparticle accelerator

Experimentally measured cross sections are presented for the natCu(α, xn)66,67,68Ga and 68Zn(p, xn)67,68Ga nuclear processes up to 36 and 20 MeV, respectively. Based on these results and the reliable cross section data available in the literature, the possible thick target yields were also calculated. Two different 68Ga production routes (Cu+α and Zn+p) are discussed in detail, especially with regard to the 66Ga and 67Ga contamination levels as a function of the target enrichment level and the incident bombarding energies. Both processes can be used for in-house 68Ga production with low (<1%) 66Ga and/or 67Ga EOB contamination using enriched 68Zn (>80%) or 65Cu (>95%) target. The maximum available yield on 100% enriched 68Zn and 65Cu (irradiation time: 2.25 h; bombarding energy: Ep=20 MeV and E α =18 MeV) is 352.45 mCi/μA (13.04 GBq/μA) and 14.28 mCi/μA (528.36 MBq/μA), respectively.

Difficult to control asthma in the patient with pseudoachondroplasia

Pseudoachondroplasia (PsA) is a type of short-limbed dwarfism resulting from mutations in the cartilage oligomeric matrix protein gene. Skeletal involvement in the PsA is well-described but there are not any published cases reporting airways involvement. The authors present a case of a female with the PsA and congenital anomalies of the respiratory tract resulting in the tracheobronchomalacia and a difficult to control asthma.

Focal therapy for prostate cancer - where are we in 2011?

Prostate cancer treatment is a controversial topic amongst physicians and patients alike. Radical therapies such as prostatectomy and whole gland radiation offer the best outcomes in terms of oncologic efficacy, but the decision to undergo treatment must be weighed against its potential morbidity. Over the past decade, the concept of focal therapy for prostate cancer has been introduced as a potential method of achieving oncologic control with a lesser degree of morbidity. Focal therapy refers to isolated ablation of a tumor focus with sparing of uninvolved, surrounding tissue. While it remains in the early stages of development, considerable research is underway that will help determine the optimal method of achieving this goal. Current areas of investigation include appropriate candidate selection, lesion identification, modality of treatment, and follow-up strategies.

Contrast-enhanced ultrasound in oncology

In patients with known malignant disease, 51% of liver lesions less than 1.5 cm turn out to be benign. Whether the probability of malignancy is high or low, further investigations are often necessary to definitely exclude malignancy. Contrast-enhanced ultrasonography has a prominent role in lesion characterization with a diagnostic accuracy comparable with computed tomography and magnetic resonance imaging. Anti-angiogenic treatment is common in most oncological institutions and the response evaluation is a new challenge with a research focus on the change in tumour vasculature and perfusion. In planning biopsies, CEUS can identify necrotic and viable areas of tumours and improve the diagnostic accuracy.

Differentiation of benign from malignant induced ascites by measuring gallbladder wall thickness

INTRODUCTION

There are multiple causes for ascites and conventional diagnostic method for most of them is paracentesis. This method is invasive and time consuming. The aim of this study is to survey the reliability of measuring gallbladder wall thickness to discriminate between cirrhotic and malignant ascites.

MATERIALS AND METHODS

In our study we measured the gallbladder wall thickness by ultrasonography in 100 consecutive patients with portal hypertension induced ascites and in 100 consecutive patients with peritoneal carcinomatosis induced ascites.

RESULTS

The mean Gallbladder wall thickness was 3.94±0.69 mm in cirrhotic patients and 2.26±0.62 mm in patients with peritoneal carcinomatosis. Gallbladder wall thickening in cirrhotic patients was significantly more compared to patients with peritoneal carcinomatosis (p-value=0.001).

CONCLUSION

This study shows that the thickened gallbladder wall in patients with ascites is highly predictive for diagnosis of portal hypertension induced ascites.

A pilot study of contrast harmonic endosonography using DEFINITY™ in the evaluation of suspected pancreatic and peri-ampullary malignancies

AIM: Contrast harmonic endosonography (CHEUS) is not widely available. This study assessed the utility of CHEUS using DEFINITY™, a second generation ultrasonic contrast agent, in the evaluation of suspected pancreatic and peri-ampullary malignancies. METHODS: Prospectively enrolled patients with suspected pancreatic and peri-ampullary malignancies underwent EUS followed by CHEUS. The incremental yield of CHEUS over EUS was analyzed. The gold standard for diagnosis of malignancy was positive cytology or histology; a negative diagnosis for malignancy was based on negative cytology or histology and benign clinical course. RESULTS: Twenty-nine patients were enrolled and underwent CHEUS. The final diagnoses were: pancreatic adenocarcinoma (16/29); metastases to pancreas (4/29); pancreatitis with inflammatory mass (4/29); normal pancreas with focal fat sparing (1/29); ampulla adenocarcinoma (2/29); serous cystic neoplasm (1/29); peri-pancreatic lymph node due to lymphoma (1/29). One bengin case of chronic pancreatitis had calcification casting artifacts that prevented accurate EUS examination and was excluded, leaving 28 cases for comparative analysis between EUS and CHEUS. CHEUS enhanced tumor margins. CHEUS detected vascular invasion missed by EUS in 2/16 patients with pancreatic adenocarcinoma. Masses appeared hypoechoic with EUS. With CHEUS malignant masses had an inhomogeneous hypoechoic pattern associated with abnormal vessels while lesions due to focal pancreatitis or fat sparing were characterized by diffuse enhancement (p<0.001). CONCLUSION: CHEUS improved the visualization of tumor margins and vascular invasion, and differentiated benign from malignant masses.

Differentiation between pancreatic carcinoma and mass-forming chronic pancreatitis: usefulness of high b value diffusion-weighted imaging

OBJECTIVE

To investigate the value of high b value diffusion-weighted (DW) imaging in differentiating between pancreatic carcinoma and mass-forming chronic pancreatitis (MFCP).

METHODS

Fifty-one consecutive patients with pathology-proven pancreatic carcinoma (n = 37) or MFCP (n = 14) were evaluated with DW imaging (b value, 0 and 1000 s/mm(2)) at a 3-T MR system. Overall 20 healthy volunteers were evaluated as the control group. The apparent diffusion coefficient (ADC) values of normal pancreas, pancreatic carcinoma, MFCP, and mass-associated obstructive pancreatitis were measured.

RESULTS

On high b value (1000 s/mm(2) ) DW images, both pancreatic carcinoma and MFCP were hyperintense focal lesions; mass-associated obstructive pancreatitis occurred in 17 of 37 (45.9%) pancreatic carcinoma and 8 of 14 (57.1%) MFCP. The ADC (×10(-3) mm(2) /s) of the pancreatic carcinomas (1.06 ± 0.15) was significantly lower than that of normal pancreas (1.47 ± 0.18; P < 0.01), MFCP (1.35 ± 0.14; P < 0.01) and mass-associated chronic pancreatitis (1.44 ± 0.17; P < 0.01). The ADC of MFCP was also lower than that in the normal pancreas (P = 0.025), whereas the ADC of mass-associated obstructive pancreatitis was not different from those of the MFCP (P = 0.113) and normal pancreas (P = 0.544). When 1.195 was used as the optimal cut-off value, ADC quantification obtained a sensitivity of 85.7% and a specificity of 86.5% for differentiating pancreatic carcinomas from MFCP.

CONCLUSION

High b value DW imaging in combination with ADC quantification at a 3-T MR system is useful in differentiating between pancreatic carcinoma and MFCP.

Genetic testing for early detection of individuals at risk of coronary heart disease and monitoring response to therapy: challenges and promises

Coronary heart disease (CHD) often presents suddenly with little warning. Traditional risk factors are inadequate to identify the asymptomatic high-risk individuals. Early identification of patients with subclinical coronary artery disease using noninvasive imaging modalities would allow the early adoption of aggressive preventative interventions. Currently, it is impractical to screen the entire population with noninvasive coronary imaging tools. The use of relatively simple and inexpensive genetic markers of increased CHD risk can identify a population subgroup in which benefit of atherosclerotic imaging modalities would be increased despite nominal cost and radiation exposure. Additionally, genetic markers are fixed and need only be measured once in a patient's lifetime, can help guide therapy selection, and may be of utility in family counseling.

Assessment of contralateral mammary gland dose in the treatment of breast cancer using accelerated hypofractionated radiotherapy

AIM: To measure the dose distribution, related to the treatment planning calculations, in the contralateral mammary gland of breast cancer patients treated with accelerated hypofractionated 3-dimensional conformal radiotherapy.

METHODS: Thirty-four prospectively selected female patients with right breast cancer (pN0, negative surgical margins) were treated with breast-conserving surgery. A total dose of 42.5 Gy (2.66 Gy/fraction) was prescribed; it was requested that planning target volumes be covered by the 95% isodose line. The contralateral mammary gland was defined on CT simulation. The dose received was evaluated by dose volume histograms.

RESULTS: The measured contralateral breast doses were: (1) Dose maximum: 290-448 cGy [Equivalent (Eq) 337-522 cGy]; (2) Mean dose: 45-70 cGy (Eq 524-815 cGy); and (3) Median dose: 29-47 cGy (337-547 cGy) for total primary breast dose of 42.5 Gy in 16 equal fractions. The spearman rho correlation showed statistical significance between the contralateral breast volume and maximum dose (P = 0.0292), as well as mean dose (P = 0.0025) and median dose (P = 0.046) to the breast.

CONCLUSION: Minimizing the dose to the contralateral breast has to be one of the priorities of the radiation oncologist when using short schedules because of the radiosensitivity of this organ at risk. Further study is necessary to assess the long-term clinical impact of this schedule.

A careful evaluation of scout CT lateral radiograph may prevent unreported vertebral fractures

OBJECTIVES

Our purpose was to review scout CT lateral radiographs to reveal osteoporotic vertebral fractures unreported by radiologists and to explore scout CT as a potential diagnostic tool in the detection of vertebral fractures.

METHODS

We considered 500 patients (303 males, 197 females, age 64.6±13.5 year-old). Our investigation was firstly focused on scout CT lateral images to detect vertebral fractures with a combined semiquantitative and quantitative diagnostic approach. Findings addressed to vertebral fracture were subsequently confirmed by multiplanar sagittal CT reconstructions. Whenever a vertebral fracture was discovered the radiologist report was read and a collection of patient anamnesis followed to understand whether fractures were already known.

RESULTS

In 44/500 patients (8.8%) the evaluation on scout CT was incomplete or limited for patient/technical-based conditions, and 15 were excluded from the analysis. In 67/485 patients (13.8%) 99 vertebral fractures were detected. Among 67 fractured patients only 18 (26.9%) were previously diagnosed by radiologists. However, in the clinical history of 32 patients vertebral fractures were already known.

CONCLUSIONS

The perception and sensibility to vertebral fractures among radiologists are still poor when the assessment of the spine is not the aim of the examination. Short time spent for the evaluation of scout CT lateral radiographs could improve our accuracy.

Radiofrequency ablation for the treatment of hepatocellular carcinoma with decompensated cirrhosis

BACKGROUND

Radiofrequency ablation (RFA) is used to treat early-stage hepatocellular carcinoma (HCC), but is sometimes avoided in patients with decompensated liver cirrhosis because of the possible side effect of deterioration of liver function.

AIMS

In this study, we report the safety and effects of RFA for treating HCC patients with Child-Pugh B/C liver cirrhosis.

METHODS

Sixty-six consecutive HCC patients with Child-Pugh B/C cirrhosis, who were treated by RFA, were enrolled in this study. We analyzed patient outcomes, the complications of RFA, and changes in liver function and tumor markers.

RESULTS

Fifty-six patients were classified as Child-Pugh class B, and 10 were classified as class C. The overall survival rates in patients with Child-Pugh B and C cirrhosis were 82 and 83% at 1 year and 47 and 31% at 3 years, respectively. Serum total bilirubin (T.Bil), albumin, prothrombin time, ascites, and encephalopathy were unchanged at 1, 3, and 6 months after RFA in patients with Child-Pugh B cirrhosis; however, serum T.Bil levels increased significantly at 6 months after RFA in 6/10 (60%) patients with Child-Pugh C cirrhosis. Hemothorax and rupture of esophageal varices were observed in 2 patients; however, there were no complications related to poor liver function.

CONCLUSION

RFA is a useful modality for treating HCC in patients with poor liver function such as Child-Pugh B and C, but careful monitoring after RFA must be needed.

EUS for diagnosis of malignant biliary stricture: an analysis of 13 cases

AIM: To compare the clinical value of endoscopic ultrasonography (EUS), endoscopic retrograde cholangiopancreatography (ERCP) and magnetic resonance cholangiopancreatography (MRCP) in the diagnosis of malignant biliary stricture.

METHODS: The imaging data for 76 patients with malignant biliary stricture who underwent EUS, ERCP or MRCP from January 2008 to May 2010 were retrospectively analyzed. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of each test were compared.

RESULTS: EUS had significantly higher sensitivity (94.2% vs 78.5%), specificity (84.6% vs 57.1%), positive predictive value (89.1% vs 64.5%), negative predictive value (73.3% vs 41.3%) and accuracy (91.6% vs 71.6%) than MRCP in the diagnosis of malignant biliary stricture. EUS had significantly higher sensitivity (94.2% vs 80.5%), specificity (84.6% vs 68.4%) and accuracy (91.6% vs 71.6%) than ERCP in the diagnosis of malignant biliary stricture.

CONCLUSION: EUS has higher sensitivity, specificity and accuracy than MRCP and ERCP in the diagnosis of malignant biliary stricture.

Effect of SonoVue on the synovial membrane in rabbit knees

OBJECTIVES

The purpose of this study was to evaluate the effect of intra-articular injection of SonoVue (sulfur hexafluoride with a phospholipid shell; Bracco SpA, Milan, Italy) on the synovial membrane in an animal model.

METHODS

Twenty-one New Zealand White rabbits (42 knees) were used in this study. We injected the knees with normal saline (saline group; n = 21) and SonoVue (SonoVue group; n = 21). A histologic examination of the knees was performed out at 3 and 12 hours and 3, 7, 15, 30, and 45 days after injection. Four histologic parameters (synovial hyperplasia, synovial stroma, vascular dilatation, and inflammatory infiltrates) were graded separately.

RESULTS

We found no significant differences in this study for synovial hyperplasia, vascular dilatation, or inflammatory infiltrates between the saline and SonoVue groups. A significant difference was only observed for synovial stroma (P < .05), and most of the histologic changes were mild in the saline group and moderate in the SonoVue group. The histologic changes observed in this study are considered transitory and reversible.

CONCLUSIONS

The results suggest that intra-articular injection of SonoVue is a safe procedure.

Poul Erik Andersen's radiological work on Osteochondrodysplasias and interventional radiology

Poul Erik Andersen is a Professor and Interventional Radiologist at the University of Southern Denmark, Odense and Odense University Hospital, Denmark. His innovative and expertise is primarily in vascular interventions where he has introduced and developed many procedures at Odense University Hospital. His significant experience and extensive scientific work has led to many posts in the Danish Society of Interventional Radiology, the European Society of Radiology and the Cardiovascular and Interventional Radiological Society of Europe, where he is a fellow and has passed the European Board of Interventional Radiology - The European qualification in Interventional Radiology.

[Malignant focal liver lesions]

Focal liver lesions are a very common occurrence. The detection and differentiation of such lesions is particularly important for the management of oncology patients and is a core task for radiology. The early and conclusive detection of malignant liver processes in a cost-efficient manner and with a low radiation dose for the patient requires systematic and skillful use of the various radiological methods. This review explains the application of current radiological methods for the detection and differentiation of malignant liver lesions and the typical appearance of the most commonly found liver malignancies.

Assessment and characterisation of common renal masses with CT and MRI

Objective

Owing to the widespread use of abdominal imaging studies the detection rate of solid renal masses has increased, and an accurate characterisation of imaging features of renal masses has become more essential for case management.

Method and results

MR imaging (MRI) and computed tomography (CT) are frequently used modalities for detection and differentiation of renal masses. This article gives a review of imaging characteristics of benign and malignant renal masses, discussing their appearance in CT and MR imaging. Advanced MR techniques like diffusion-weighted imaging and apparent diffusion coefficient (ADC) mapping, which have shown promising results in the differentiation between benign and malignant renal lesions, will be introduced.

Conclusion

MRI and CT are useful in the characterisation and estimation of the prognosis for renal masses.

Radiofrequency ablation of hepatocellular carcinoma: Current status

Ablation therapy is one of the best curative treatment options for malignant liver tumors, and can be an alternative to resection. Radiofrequency ablation (RFA) of primary and secondary liver cancers can be performed safely using percutaneous, laparoscopic, or open surgical techniques, and RFA has markedly changed the treatment strategy for small hepatocellular carcinoma (HCC). Percutaneous RFA can achieve the same overall and disease-free survival as surgical resection for patients with small HCC. The use of a laparoscopic or open approach allows repeated placements of RFA electrodes at multiple sites to ablate larger tumors. RFA combined with transcatheter arterial chemoembolization will make the treatment of larger tumors a clinically viable treatment alternative. However, an accurate evaluation of treatment response is very important to secure successful RFA therapy. Since a sufficient safety margin (at least 0.5 cm) can prevent local tumor recurrences, an accurate evaluation of treatment response is very important to secure successful RFA therapy. To minimize complications of RFA, clinicians should be familiar with the imaging features of each type of complication. Appropriate management of complications is essential for successful RFA treatment.

A steroid-conjugated magnetic resonance probe enhances contrast in progesterone receptor expressing organs and tumors in vivo

Progesterone receptor (PR) is a significant biomarker in diseases such as endometriosis and breast, ovarian, and uterine cancers that is associated with disease prognosis and therapeutic efficacy. While receptor status is currently determined by immunohistochemistry assays, the development of noninvasive PR imaging agents could improve molecular characterization, treatment decisions, and disease monitoring. ProGlo, a progesterone-conjugated magnetic resonance imaging (MRI) contrast agent, was evaluated in vivo to determine whether it targets and enhances signal intensity in organs and tumors that express high PR levels. A tissue distribution study indicated that ProGlo accumulates in the PR-rich uterus, which was confirmed by in vivo imaging studies. Ex vivo images of these organs revealed that ProGlo was distributed in the substructures that express high PR levels. In xenograft tumor models, ProGlo was taken up to a greater extent than the nonfunctionalized Gd-DO3A in tumors, particularly in PR(+) tumors. The ability to accumulate and enhance signal intensity in PR(+) organs and tumors suggests that ProGlo may be a promising MRI probe for PR(+) diseases.

Pathological and MR-DWI study of the acute hepatic injury model after stem cell transplantation

AIM: To investigate apparent diffusion coefficient (ADC) values as an indication of reconditioning of acute hepatic injury (AHI) after allogeneic mononuclear bone marrow cell (MBMC) transplantation.

METHODS: Three groups were used in our study: a cell transplantation group (n = 21), transplantation control group (n = 21) and normal control group (n = 10). AHI model rabbits in the cell transplantation group were injected with 5 mL of MBMC suspension at multiple sites in the liver and the transplantation controls were injected with 5 mL D-Hanks solution. At the end of the 1st, 2nd and 4th wk, 7 rabbits were randomly selected from the cell transplantation group and transplantation control group for magnetic resonance diffusion-weighted imaging (MR-DWI) and measurement of the mean ADC values of injured livers. After MR-DWI examination, the rabbits were sacrificed and the livers subjected to pathological examination. Ten healthy rabbits from the normal control group were used for MR-DWI examination and measurement of the mean ADC value of normal liver.

RESULTS: At all time points, the liver pathological scores from the cell transplantation group were significantly lower than those in the transplantation control group (27.14 ± 1.46 vs 69.29 ± 6.16, 22.29 ± 2.29 vs 57.00 ± 1.53, 19.00 ± 2.31 vs 51.86 ± 6.04, P = 0.000). The mean ADC values of the cell transplantation group were significantly higher than the transplantation control group ((1.07 ± 0.07) × 10^-3 mm²/s vs (0.69 ± 0.05) × 10^-3 mm²/s, (1.41 ± 0.04) × 10^-3 mm²/s vs (0.84 ± 0.06) × 10^-3 mm²/s, (1.68 ± 0.04) × 10^-3 mm²/s vs (0.86 ± 0.04) × 10^-3 mm²/s, P = 0.000). The pathological scores of the cell transplantation group and transplantation control group gradually decreased. However, their mean ADC values gradually increased to near that of the normal control. At the end of the 1st wk, the mean ADC values of the cell transplantation group and transplantation control group were significantly lower than those of the normal control group [(1.07 ± 0.07) × 10^-3 mm²/s vs (1.76 ± 0.03) × 10^-3 mm²/s, (0.69 ± 0.05) × 10^-3 mm²/s vs (1.76 ± 0.03) × 10^-3 mm²/s, P = 0.000]. At any 2 time points, the pathological scores and the mean ADC values of the cell transplantation group were significantly different (P = 0.000). At the end of the 1st wk, the pathological scores and the mean ADC values of the transplantation control group were significantly different from those at the end of the 2nd and 4th wk (P = 0.000). However, there was no significant difference between the 2nd and 4th wk (P = 0.073 and 0.473, respectively). The coefficient of correlation between the pathological score and the mean ADC value in the cell transplantation group was -0.883 (P = 0.000) and -0.762 (P = 0.000) in the transplantation control group.

CONCLUSION: Tracking the longitudinally dynamic change in the mean ADC value of the AHI liver may reflect hepatic injury reconditioning after allogeneic MBMC transplantation.

Recent advances in understanding pancreatic endocrine tumors

Pancreatic endocrine tumors (PETs) are uncommon and have an incidence of approximately 4-5 per 1 000 000 people, accounting for 1%-2% of all pancreatic neoplasms. They usually grow slowly, eventually metastasize and lead to death. PETs can be classified as functioning or non-functioning tumors based on clinical manifestation. The pathogenesis of PETs may involve abnormal expression of CD10, CD44, CD99, p27, COX2, Ki-67, KIT, CK19, ARHI, RUNX1T1, and survivin genes, loss of heterozygosity on chromosomes, hypermethylation of tumor suppressor genes, and overexpression of ghrelin. Chromogranin A (CgA) has long been used as an important broad-spectrum marker for the identification of PETs. KIT and endoglin are new independent prognostic markers for PETs. The diagnosis is based on histopathology demonstrating neuroendocrine features such as positive staining for chromogranin A and specific hormones such as gastrin, proinsulin, vasoactive intestinal peptide (VIP) and glucagon. In addition to standard localization procedures, radiology diagnosis including computed tomography (CT), positron emission tomography and computed tomography (PET/CT), magnetic resonance imaging (MRI), ultrasound (US), endoscopic ultrasound (EUS), laparoscopic ultrasound (LUS), dynamic enhanced spiral CT, selective arterial stimulation and venous sampling (ASVS), and somatostatin receptor scintigraphy (SRS) are performed. Surgery is still one of the cornerstones in the management of PETs. Laparoscopy, and drugs of somatostatin analogs are routinely used. Understanding of the recent advances of PETs has important implications for the early diagnosis and treatment of PETs.

Era of diagnostic and interventional ultrasound

It is an era of diagnostic and interventional ultrasound (US). Various new techniques such as three-dimensional US (3D US), interventional US, and contrast-enhanced US (CEUS) have been introduced into clinical practice. Dr. Xu and his colleagues have taken advantage of these techniques and carried out a series of relevant studies. Their use of 3D US in the liver, gallbladder, liver tumor volumetry, guidance for ablation, and 3D CEUS has widened the application of 3D US in the clinic. They found that prognosis in patients with hepatocellular carcinoma (HCC) after thermal ablation with curative intent was determined by treatment response to ablation, pretreatment serum AFP, and liver function reserve. Tumor response to treatment was the most predictive factor for long-term survival. They compared the use of percutaneous microwave ablation and radiofrequency ablation for the treatment of HCC and found that both are effective methods in treating HCCs. The local tumor control, complications related to treatment, and long-term survival were equivalent for the two modalities. They first compared the enhancement patterns of HCC and intrahepatic cholangiocarcinoma (ICC) and proposed the diagnostic clues for ICC, liver angiomyolipoma (AML), gallbladder cancer, renal carcinoma, and renal AML, which have greatly enhanced the role of CEUS in the clinic. They also evaluated the diagnostic performance of CEUS in characterizing complex cystic focal liver lesions and the agreement between two investigators with different experience levels; and found that CEUS is especially useful for the young investigator. They assessed the effect of anti-angiogenic gene therapy for HCC treated by microbubble-enhanced US exposure and concluded that gene therapy mediated by US exposure enhanced by a microbubble contrast agent may become a new treatment option for HCC.

Whole brain radiotherapy: prognostic factors and results of a radiation boost delivered through a conventional linear accelerator

PURPOSE

Assess prognostic factors for overall survival and the potential benefit of a boost in patients treated with whole brain radiation therapy (WBRT).

METHODS AND MATERIALS

From 2002 to 2006, a retrospective analysis was made from 250 unselected consecutive patients with secondary brain metastases from lung cancer, breast cancer and melanoma. Eighteen patients received surgery and were excluded from analysis. Four potential prognostic factors have been studied: primary tumor type, gender, number of metastases and improvement of neurological symptoms after radiation therapy. A subgroup analysis was performed to determine whether an additional boost could potentially improve outcome in patients who presented with less than three metastases, performance status <2, and no surgical resection of their metastasis.

RESULTS

Average follow-up was 10.3 months. Median overall survival was 5.6 months and survival rates at 1 and 2 years were 22.7% and 10%, respectively. Age less than 65 (p<0.01), neurological improvement after WBRT (p<0.01), and presence of less than three metastases were significant factors for overall survival in multivariate analysis. When focusing on the selected subgroup (120 assessable patients), median overall survival was 4.0 months in patients with no radiation boost, versus 8.9 months in patients with radiation boost (p=0.0024).

CONCLUSIONS

Survival and prognostic factors were similar to those found in the literature. Boost delivered after WBRT by a conventional particle accelerator could provide a benefit in selected patients, especially for centers that do not have radiotherapy techniques in stereotactic conditions. This warrants further prospective assessment.

Impact of contrast enhanced MRI on lymphocyte DNA damage and serum visfatin level

OBJECTIVES

Nephrogenic systemic fibrosis is a novel clinical entity encountered in subjects undergoing contrast enhanced magnetic resonance imaging (MRI). The aim of the present study is to evaluate the impact of contrast enhanced MRI exposure on lymphocyte DNA damage and serum levels of visfatin.

DESIGN AND METHODS

Twenty-eight subjects undergoing contrast enhanced hypophysial MRI with omniscan were included in the study. Blood samples were drawn before MRI, after non-contrast MRI and after contrast enhanced MRI from each subject. Lymphocyte DNA damage was analyzed by the alkaline comet assay, whereas serum visfatin level was assessed with enzyme immuno assay.

RESULTS

Both lymphocyte DNA damage and serum visfatin levels were statistically significantly increased in samples withdrawn after contrast enhanced MRI compared to samples withdrawn after non-contrast enhanced MRI and baseline samples (ANOVA p<0.001, for both).

CONCLUSIONS

Findings of the present study revealed that the contrast enhanced MRI is associated with increased lymphocyte DNA damage and increased serum visfatin level.

Minimally invasive techniques for head and neck malignancies: current indications, outcomes and future directions

The trend toward minimally invasive surgery, appropriately applied, has evolved over the past three decades to encompass all fields of surgery, including curative intent cancer surgery of the head and neck. Proper patient and tumor selection are fundamental to optimizing oncological and functional outcomes in such a personalized approach to cancer treatment. Training, experience, and appropriate technological equipment are prerequisites for any type of minimally invasive surgery. The aim of this review was to provide an overview of currently available techniques and the evidence justifying their use. Much evidence is in favor of routine use of transoral laser resection, transoral robot-assisted surgery, transnasal endoscopic resection, sentinel node biopsy, and endoscopic neck surgery for selected malignant tumors, by experienced surgical teams. Technological advances will enhance the scope of this type of surgery in the future and physicians need to be aware of the current applications and trends.

Refractory gastroesophageal variceal bleeding secondary to neuroendocrine carcinoma in the pancreatic tail

The main cause of gastroesophageal variceal bleeding (GEVB) is portal hypertension (PH) due to liver cirrhosis. Here, we report a case of regional PH and refractory GEVB secondary to neuroendocrine carcinoma (NC) in the pancreatic tail. This condition was treated using a pancreatic tail resection, splenectomy, and portal azygous devascularization. Regional PH caused by a pancreatic NC is rare and is usually presented as isolated gastric varices. This case report of regional PH details simultaneous esophageal and gastric varices that were caused by a pancreatic NC, which is a rare occurrence. Therefore, after excluding liver cirrhosis, unusual causes should be considered in cases of refractory GEVB with PH. and IAP.

Pulmonary ultrasonography in the follow-up of respiratory distress syndrome on preterm newborns. Reduction of X-ray exposure

PURPOSE

Respiratory distress syndrome (RDS) is the most common cause of respiratory failure in preterm neonates, whose lungs are often immature. The diagnosis and follow-up are based on clinical and radiographic findings. Due to the problem of air artifacts, ultrasonography (US) is not used routinely in the diagnosis of lung diseases. However, when the alveolar air content decreases, as it does in RDS, characteristic patterns appear that can be observed during US lung examinations. The aim of this study was to determine whether the use of chest radiographs in neonates with RDS could be reduced by the routine use of chest US for follow-up examinations.

MATERIALS AND METHODS

From April through September 2008, were enrolled all preterm newborns, with very low birth weight (VLBW), consecutive admitted in NICU with clinically and radiologically diagnosed RDS. We performed lung ultrasound examination in this patients. Video-taped US examinations were done every 8-12 h until clinical resolution of the disease was observed. Chest X-rays were performed only in unclear cases. We compared the number of chest radiographs obtained in the NICU during this period and during the preceding six months.

RESULTS

105 serial US lung examinations were performed in 21 preterm infant with clinically and radiologically diagnosed RDS. US lung examinations revealed "comet-tail" artifacts that were compact, diffuse, and symmetrically distributed throughout both lung fields. In 8 cases, the pleural line was also extensively thickened and irregular, and in 7 cases multiple subpleural hypoechoic areas indicative of lung consolidation were observed (mainly on posterior and lateral scans). The mean number of chest radiographs per infant performed in the NICU during the study period was significantly lower than that of the preceding six months (2.6 ± 1 versus 3.8 ± 1.5; p < 0.05).

CONCLUSIONS

Chest ultrasound is a valid alternative for the follow-up of VLBW infants with RDS, which can decrease the need for chest X-rays and reduce patient exposure to ionizing radiation.

Comparison of magnetic resonance angiography scans on 1.5, 3, and 7 Tesla units: a quantitative study of 3-dimensional cerebrovasculature

BACKGROUND

Although multiple studies demonstrate benefits of high field imaging of cerebrovasculature, a detailed quantitative analysis of complete cerebrovascular system is unavailable. To compare quality of MR angiography (MRA) acquisitions at various field strengths, we used 3-dimensional (3D) geometric cerebrovascular models extracted from 1.5 T/3 T/7 T scans.

METHODS

The 3D cerebrovascular models were compared in volume, length, and number of branches. A relationship between the vascular length and volume was statistically derived. Acquisition performance was benchmarked against the maximum volume at infinitive length.

RESULTS

The numbers of vessels discernible on 1.5 T/3 T/7 T are 138/363/907. 3T shows 3.3(1.9) and 7 T 1.2(9.1) times more arteries (veins) than 1.5 T. The vascular lengths and volumes at 1.5 T/3 T/7 T are 3.7/12.5/22.7 m and 15.8/26.6/28.0 cm(3). For arteries: 3T-1.5 T gain is very high in length, high in volume; 7 T-3T gain is medium in length, small in volume. For veins: 3 T-1.5 T gain is moderate in length, high in volume; 7 T-3T gain is very high in length, moderate in volume. 1.5 T shows merely half of vascular volume. At 3 T 6%, while at 7 T only 1% of vascular volume is missing.

CONCLUSION

Our approach differs from standard approaches based on visual assessment and signal (contrast)-to-noise ratio. It also measures absolute acquisition performance, provides a unique length-volume relationship, and predicts length/volume for intermediate teslages.

Semi-LASER localized dynamic 31P magnetic resonance spectroscopy in exercising muscle at ultra-high magnetic field

Magnetic resonance spectroscopy (MRS) can benefit from increased signal-to-noise ratio (SNR) of high magnetic fields. In this work, the SNR gain of dynamic ³¹P MRS at 7 T was invested in temporal and spatial resolution. Using conventional slice selective excitation combined with localization by adiabatic selective refocusing (semi-LASER) with short echo time (TE = 23 ms), phosphocreatine quantification in a 38 mL voxel inside a single exercising muscle becomes possible from single acquisitions, with SNR = 42 ± 4 in resting human medial gastrocnemius.

The method was used to quantify the phosphocreatine time course during 5 min of plantar flexion exercise and recovery with a temporal resolution of 6 s (the chosen repetition time for moderate T₁ saturation). Quantification of inorganic phosphate and pH required accumulation of consecutively acquired spectra when (resting) Pi concentrations were low. The localization performance was excellent while keeping the chemical shift displacement acceptably small. The SNR and spectral line widths with and without localization were compared between 3 T and 7 T systems in phantoms and in vivo.

The results demonstrate that increased sensitivity of ultra-high field can be used to dynamically acquire metabolic information from a clearly defined region in a single exercising muscle while reaching a temporal resolution previously available with MRS in non-localizing studies only. The method may improve the interpretation of dynamic muscle MRS data. Magn Reson Med, 2011. © 2011 Wiley-Liss, Inc.

Primary gastrointestinal lymphoma

Gastrointestinal tract is the most common extranodal site involved by lymphoma with the majority being non-Hodgkin type. Although lymphoma can involve any part of the gastrointestinal tract, the most frequent sites in order of its occurrence are the stomach followed by small intestine and ileocecal region. Gastrointestinal tract lymphoma is usually secondary to the widespread nodal diseases and primary gastrointestinal tract lymphoma is relatively rare. Gastrointestinal lymphomas are usually not clinically specific and indistinguishable from other benign and malignant conditions. Diffuse large B-cell lymphoma is the most common pathological type of gastrointestinal lymphoma in essentially all sites of the gastrointestinal tract, although recently the frequency of other forms has also increased in certain regions of the world. Although some radiological features such as bulky lymph nodes and maintenance of fat plane are more suggestive of lymphoma, they are not specific, thus mandating histopathological analysis for its definitive diagnosis. There has been a tremendous leap in the diagnosis, staging and management of gastrointestinal lymphoma in the last two decades attributed to a better insight into its etiology and molecular aspect as well as the knowledge about its critical signaling pathways.

Quantitative analyses of pediatric cervical spine ossification patterns using computed tomography

The objective of the present study was to quantify ossification processes of the human pediatric cervical spine. Computed tomography images were obtained from a high resolution scanner according to clinical protocols. Bone window images were used to identify the presence of the primary synchondroses of the atlas, axis, and C3 vertebrae in 101 children. Principles of logistic regression were used to determine probability distributions as a function of subject age for each synchondrosis for each vertebra. The mean and 95% upper and 95% lower confidence intervals are given for each dataset delineating probability curves. Posterior ossifications preceded bilateral anterior closures of the synchondroses in all vertebrae. However, ossifications occurred at different ages. Logistic regression results for closures of different synchondrosis indicated p-values of <0.001 for the atlas, ranging from 0.002 to <0.001 for the axis, and 0.021 to 0.005 for the C3 vertebra. Fifty percent probability of three, two, and one synchondroses occurred at 2.53, 6.97, and 7.57 years of age for the atlas; 3.59, 4.74, and 5.7 years of age for the axis; and 1.28, 2.22, and 3.17 years of age for the third cervical vertebrae, respectively. Ossifications occurring at different ages indicate non-uniform maturations of bone growth/strength. They provide an anatomical rationale to reexamine dummies, scaling processes, and injury metrics for improved understanding of pediatric neck injuries.