Artificial Intelligence-based CT Assessment of Bronchiectasis: The COPDGene Study

Background CT is the standard method used to assess bronchiectasis. A higher airway-to-artery diameter ratio (AAR) is typically used to identify enlarged bronchi and bronchiectasis; however, current imaging methods are limited in assessing the extent of this metric in CT scans. Purpose To determine the extent of AARs using an artificial intelligence-based chest CT and assess the association of AARs with exacerbations over time. Materials and Methods In a secondary analysis of ever-smokers from the prospective, observational, multicenter COPDGene study, AARs were quantified using an artificial intelligence tool. The percentage of airways with AAR greater than 1 (a measure of airway dilatation) in each participant on chest CT scans was determined. Pulmonary exacerbations were prospectively determined through biannual follow-up (from July 2009 to September 2021). Multivariable zero-inflated regression models were used to assess the association between the percentage of airways with AAR greater than 1 and the total number of pulmonary exacerbations over follow-up. Covariates included demographics, lung function, and conventional CT parameters. Results Among 4192 participants (median age, 59 years; IQR, 52-67 years; 1878 men [45%]), 1834 had chronic obstructive pulmonary disease (COPD). During a 10-year follow-up and in adjusted models, the percentage of airways with AARs greater than 1 (quartile 4 vs 1) was associated with a higher total number of exacerbations (risk ratio [RR], 1.08; 95% CI: 1.02, 1.15; P = .01). In participants meeting clinical and imaging criteria of bronchiectasis (ie, clinical manifestations with ≥3% of AARs >1) versus those who did not, the RR was 1.37 (95% CI: 1.31, 1.43; P < .001). Among participants with COPD, the corresponding RRs were 1.10 (95% CI: 1.02, 1.18; P = .02) and 1.32 (95% CI: 1.26, 1.39; P < .001), respectively. Conclusion In ever-smokers with chronic obstructive pulmonary disease, artificial intelligence-based CT measures of bronchiectasis were associated with more exacerbations over time. Clinical trial registration no. NCT00608764 © RSNA, 2022 Supplemental material is available for this article. See also the editorial by Schiebler and Seo in this issue.

Computed tomography radiomic features hold prognostic utility for canine lung tumors: An analytical study

Quantitative analysis of computed tomography (CT) radiomic features is an indirect measure of tumor heterogeneity, which has been associated with prognosis in human lung carcinoma. Canine lung tumors share similar features to human lung tumors and serve as a model in which to investigate the utility of radiomic features in differentiating tumor type and prognostication. The purpose of this study was to correlate first-order radiomic features from canine pulmonary tumors to histopathologic characteristics and outcome. Disease-free survival, overall survival time and tumor-specific survival were calculated as days from the date of CT scan. Sixty-seven tumors from 65 dogs were evaluated. Fifty-six tumors were classified as primary pulmonary adenocarcinomas and 11 were non-adenocarcinomas. All dogs were treated with surgical resection; 14 dogs received adjuvant chemotherapy. Second opinion histopathology in 63 tumors confirmed the histologic diagnosis in all dogs and further characterized 53 adenocarcinomas. The median overall survival time was longer (p = 0.004) for adenocarcinomas (339d) compared to non-adenocarcinomas (55d). There was wide variation in first-order radiomic statistics across tumors. Mean Hounsfield units (HU) ratio (p = 0.042) and median mean HU ratio (p = 0.042) were higher in adenocarcinomas than in non-adenocarcinomas. For dogs with adenocarcinoma, completeness of excision was associated with overall survival (p<0.001) while higher mitotic index (p = 0.007) and histologic score (p = 0.037) were associated with shorter disease-free survival. CT-derived tumor variables prognostic for outcome included volume, maximum axial diameter, and four radiomic features: integral total, integral total mean ratio, total HU, and max mean HU ratio. Tumor volume was also significantly associated with tumor invasion (p = 0.044). Further study of radiomic features in canine lung tumors is warranted as a method to non-invasively interrogate CT images for potential predictive and prognostic utility.

Diffuse Paget's Disease of the Skull with Intense Uptake of Technetium-99m-Labeled Diphosphonate Tracer in Bone Scintigraphy

Imaging in patients with Paget's disease of bone is very important clinically to show the presence of Pagetic abnormalities, assess disease progression, and identify adversely affected structures throughout disease course. Abnormalities and progression may be seen on radiographs, computed tomography, magnetic resonance imaging, and nuclear imaging. Herein, we report a case Paget's disease of bone showing diffuse characteristic pathology using technetium-99m-labelled diphosphonate tracer in bone scintigraphy (nuclear imaging). This case emphasizes the ability of nuclear imaging to rapidly visualize and assess progressive distribution of Pagetic involvement in a patient previously diagnosed with pituitary adenoma and mild Paget's disease of the skull.

A CT radiomics analysis of COVID-19-related ground-glass opacities and consolidation: Is it valuable in a differential diagnosis with other atypical pneumonias?

PURPOSE

To evaluate the discrimination of parenchymal lesions between COVID-19 and other atypical pneumonia (AP) by using only radiomics features.

METHODS

In this retrospective study, 301 pneumonic lesions (150 ground-glass opacity [GGO], 52 crazy paving [CP], 99 consolidation) obtained from nonenhanced thorax CT scans of 74 AP (46 male and 28 female; 48.25±13.67 years) and 60 COVID-19 (39 male and 21 female; 48.01±20.38 years) patients were segmented manually by two independent radiologists, and Location, Size, Shape, and First- and Second-order radiomics features were calculated.

RESULTS

Multiple parameters showed significant differences between AP and COVID-19-related GGOs and consolidations, although only the Range parameter was significantly different for CPs. Models developed by using the Bayesian information criterion (BIC) for the whole group of GGO and consolidation lesions predicted COVID-19 consolidation and AP GGO lesions with low accuracy (46.1% and 60.8%, respectively). Thus, instead of subjective classification, lesions were reclassified according to their skewness into positive skewness group (PSG, 78 AP and 71 COVID-19 lesions) and negative skewness group (NSG, 56 AP and 44 COVID-19 lesions), and group-specific models were created. The best AUC, accuracy, sensitivity, and specificity were respectively 0.774, 75.8%, 74.6%, and 76.9% among the PSG models and 0.907, 83%, 79.5%, and 85.7% for the NSG models. The best PSG model was also better at predicting NSG lesions smaller than 3 mL. Using an algorithm, 80% of COVID-19 and 81.1% of AP patients were correctly predicted.

CONCLUSION

During periods of increasing AP, radiomics parameters may provide valuable data for the differential diagnosis of COVID-19.

Early-phase pelvic bone SPECT: Simulation and comparison of several acquisition protocols to reduce bladder artifact and improve image quality

Tomoscintigraphic reconstruction in nuclear medicine assumes that the distribution of the tracer is unchanged in the volume of interest throughout the duration of the acquisition. This condition is however not met in early-phase bone scintigraphy and early-phase pelvic SPECT may display helical artifacts due to the filling of the bladder. Those artifacts may hamper proper interpretation of surrounding bone areas. The aim of this study was to construct a 4D digital pelvic phantom to simulate different acquisition protocols and optimize the acquisition.A 4D digital pelvic phantom was generated with a dynamic component consisting in an expanding bladder with 2 ureters and a static part consisting in the 2 kidneys, bone structures, and soft tissues. Projection data were obtained using an attenuated Radon transform function. Four acquisitions protocols were tested: 32 projections of 16 seconds (32-16-1), 32 projections of 8 seconds (32-8-1), 2 consecutive SPECT of 32 projections of 4 seconds (32-4-2) and 2 consecutive SPECT of 16 projections of 8 seconds (16-8-2). The optimal protocol was then tested on one patient.The amplitude of the artifacts was reduced with the 32-8-1, 32-4-2, and 16-8-2 protocols. The 16-8-2 protocol had the highest signal to noise ratio among those 3 protocols. The bladder artifact was visually markedly reduced on the patient acquisition with a 16-8-2 protocol.Two successive early-phase bone SPECT, with a lower number of projection than the usual protocol reduce the impact of the helical artifacts around the bladder.

A Randomized Controlled Study of Integrated Smoking Cessation in a Lung Cancer Screening Program

INTRODUCTION

Smoking cessation activities incorporated into lung cancer screening programs have been broadly recommended, but studies to date have not shown increased quit rates associated with cessation programs in this setting. We aimed to determine the effectiveness of smoking cessation counseling in smokers presenting for lung cancer screening.

METHODS

This study is a randomized control trial of an intensive telephone-based smoking cessation counseling intervention incorporating lung cancer screening results versus usual care (information pamphlet). All active smokers enrolled in the Alberta Lung Cancer Screening Study cohort were randomized on a 1:1 ratio with a primary endpoint of self-reported 30-day abstinence at 12 months.

RESULTS

A total of 345 active smokers participating in the screening study were randomized to active smoking cessation counseling (n = 171) or control arm (n = 174). Thirty-day smoking abstinence at 12 months post-randomization was noted in 22 of 174 (12.6%) and 24 of 171 (14.0%) of participants in the control and intervention arms, respectively, a 1.4% difference (95% confidence interval: -5.9 to 8.7, p = 0.7). No statistically significant differences in 7-day or point abstinence were noted, nor were differences at 6 months or 24 months.

CONCLUSIONS

A telephone-based smoking cessation counseling intervention incorporating lung cancer screening results did not result in increased 12-month cessation rates versus written information alone in unselected smokers undergoing lung cancer screening. Routine referral of all current smokers to counseling-based cessation programs may not improve long-term cessation in this patient cohort. Future studies should specifically focus on this subgroup of older long-term smokers to determine the optimal method of integrating smoking cessation with lung cancer screening (clinicaltrials.govNCT02431962).

Clinical Spectrum of Congenital Anomalies of Kidney and Urinary Tract in Children

OBJECTIVES

To evaluate the clinical spectrum and patterns of clinical presentation in congenital anomalies of kidney and urinary tract.

METHODS

We enrolled 307 consecutively presenting children with congenital anomalies of kidney and urinary tract at the pediatric nephrology clinic. Patients were evaluated clinically, with serum biochemistry, appropriate imaging and radionuclide scans.

RESULTS

The most common anomaly was primary vesicoureteric reflux (VUR) (87, 27.3%), followed by pelviureteral junction obstruction (PUJO) (62,20.1%), multicystic dysplastic kidney (51 16.6%), non-obstructive hydronephrosis (32, 10.4%) and posterior urethral valves (PUV) (23, 7.4%). 247 (80.4%) anomalies had been identified during the antenatal period. Another 33 (10.7%) were diagnosed during evaluation of urinary tract infection, and 21 (6.8%) during evaluation for hypertension at presentation. Obstructive anomalies presented earlier than non-obstructive (7 (3, 22.5) vs 10 (4, 24) mo: (P=0.01)). The median (IQR) ages of presentation for children with PUV (n=23), VUR (n=87) and PUJO (n=62) were 4 (2, 14) mo, 10 (5, 27) mo, and 7 (3, 22.5) mo, respectively. Nine (2.9%) children had extrarenal manifestations.

CONCLUSIONS

The median age at clinical presentation for various subgroups of anomalies indicates delayed referral. We emphasize the need for prompt referral in order to initiate appropriate therapeutic strategies in children with congenital anomalies of kidney and urinary tract.

Evaluation of the tear clearance rate by dacryoscintigraphy in patients with obstructive meibomian gland dysfunction

PURPOSE

To measure tear clearance values in patients with meibomian gland dysfunction (MGD) with a dynamic nuclear medicine method, namely, dacryoscintigraphy (DSCI).

METHODS

Twenty-four MGD patients and 24 healthy volunteers were examined. During DSCI one drop of a solution with 100 MBq/mL^99mTc sodium pertechnetate was instilled with a micropipette into the lacrimal lake of both eyes. Measurements were performed according to a dynamic data acquisition protocol, which resulted in summed DSCI images. Data were also evaluated separately in special regions of interest (ROI), and consecutive time activity curves were created. Tear clearance (T½) values were calculated based on the activity curves. In addition, tear osmolarity measurements, tear breakup time (tBUT), and Schirmer I (ST_I) tests were performed prior to DSCI examination.

RESULTS

The T½ values were 29.91 ± 11.61 min in MGD patients and 6.26 ± 1.5 min in healthy controls. Tear osmolarity parameters were 308 ± 9.41 mOsm/L and 288.9 ± 6.4 mOsm/L, tBUT values were 5.54 ± 2.73 s and 11.4 ± 2.7 s, while the ST_I test values were 6.17 ± 2.78 mm and 13.58 ± 3.8 mm, respectively. The differences were significant (p < 0.01) in all cases.

CONCLUSIONS

Although the MGD patients' lacrimal drainage systems were patent their tear clearance values were significantly higher than those of healthy volunteers, which may be caused by decreased drainage of tears from the eyes towards the nasal cavity. The understanding of new features regarding the altered physico-chemical characteristics of MGD tears has been augmented by the results of this study.

Diagnosis of Deep Venous Thrombosis and Pulmonary Embolism: New Imaging Tools and Modalities

Imaging continues to be the modality of choice for the diagnosis of venous thromboembolic disease, particularly when incorporated into diagnostic algorithms. Improvement in imaging techniques as well as new imaging modalities and processing methods have improved diagnostic accuracy and additionally are being leveraged in prognostication and decision making for choice of intervention. In this article, we review the role of imaging in diagnosis and prognostication of venous thromboembolism. We also discuss emerging imaging approaches that may in the near future find clinical usefulness in improving diagnosis and prognostication as well as differentiating disease phenotypes.

Computed tomography and histopathological findings after embolization with inherently radiopaque 40μm-microspheres, standard 40μm-microspheres and iodized oil in a porcine liver model

Purpose

The present study compared standard computed tomography (CT) and histopathological findings after endovascular embolization using a prototype of inherently radiopaque 40μm-microspheres with both standard 40μm-microspheres and iodized oil in a porcine liver model.

Materials and methods

Twelve pigs were divided into six study groups, of two pigs each. Four pigs were embolized with iodized oil alone and four with radiopaque microspheres; two animals in each group were sacrificed at 2 hours and two at 7 days. Two pigs were embolized with radiopaque microspheres and heparin and sacrificed at 7 days. Two pigs were embolized with standard microspheres and sacrificed at 2 hours. CT was performed before and after segmental embolization and before sacrifice at 7 days. The distribution of embolic agent, inflammatory response and tissue necrosis were assessed histopathologically.

Results

Radiopaque microspheres and iodized oil were visible on standard CT 2 hours and 7 days after embolization, showing qualitatively comparable arterial and parenchymal enhancement. Quantitatively, the enhancement was more intense for iodized oil. Standard microspheres, delivered without contrast, were not visible by imaging. Radiopaque and standard microspheres similarly occluded subsegmental and interlobular arteries and, to a lesser extent, sinusoids. Iodized oil resulted in the deepest penetration into sinusoids. Necrosis was always observed after embolization with microspheres, but never after embolization with iodized oil. The inflammatory response was mild to moderate for microspheres and moderate to severe for iodized oil.

Conclusion

Radiopaque 40μm-microspheres are visible on standard CT with qualitatively similar but quantitatively less intense enhancement compared to iodized oil, and with a tendency towards less of an inflammatory reaction than iodized oil. These microspheres also result in tissue necrosis, which was not observed after embolization with iodized oil. Both radiopaque and standard 40μm-microspheres are found within subsegmental and interlobar arteries, as well as in hepatic sinusoids.

Case report: successful treatment of refractory SAPHO syndrome with the JAK inhibitor tofacitinib

INTRODUCTION

Synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome is an autoinflammatory disorder without standardized treatment. Janus kinase (JAK) inhibitors can block a range of cytokines and might possess significant anti-inflammatory activity. Here, we report the first case of efficacious treatment of refractory SAPHO syndrome with the JAK inhibitor tofacitinib.

CASE PRESENTATION

A 44-year-old woman presented with arthralgia in the right wrist and complained of having difficulty in doing housework. Symptoms were unresponsiveness to nonsteroidal anti-inflammatory drugs, disease-modifying antirheumatic drugs, and tumor necrosis factor inhibitors. A diagnosis of SAPHO syndrome was made based on previous dermatological and osteoarticular manifestations and bone scintigraphy findings. Oral treatment with tofacitinib at 5 mg twice daily in combination with the basic methotrexate treatment was initiated. After 4 weeks of using tofacitinib, the patient reported marked improvement of symptoms and also reported being competent in completing housework.

CONCLUSIONS

The efficacy of JAK inhibitors in treating refractory SAPHO syndrome should be noted.

The Role of Fluorine-18-Deoxyglucose (Fdg) Positron Emission Tomography (Pet) Whole Body Scan (Wbs) in the Staging and Follow-Up of Cancer Patients: Our First Experience

We report the results of FDG PET whole body scan in 75 cancer patients in whom tumor extent was defined by surgical, histological or cytological findings and clinical follow-up. Twenty-five had malignant lymphomas, 24 lung carcinomas, and 26 other types of solid tumors. Twenty-three patients were evaluated at disease onset, before therapy, and 37 at the moment of tumor recurrence; the remaining 15 patients were in complete remission after treatment and were taken as controls. Visual and quantitative PET results were compared with conventional imaging (US, CT scan and/or MRI, and Tc99m MDP bone scan).

In the 60 patients with active disease, PET as well as conventional imaging were able to locate the primary tumor in all 23 patients studied at disease onset. However, with regard to lymph node and distant metastases, PET provided the same information as conventional imaging in 31 cases (51.6%), but revealed further neoplastic foci in 29 cases (48.4%), 21 in lymph nodes and 8 at distant sites. The sensitivity of PET, in comparison with conventional imaging, was 100% versus 100% for the detection of the primary tumor, 97.6% versus 55.8% for the localization of node metastases, and 100% versus 55.5% for the visualization of distant metastases. The specificity, calculated in the group of 15 disease-free patients, was 100% for PET and 86.6% for conventional imaging. The therapeutic approach was modified in 12 patients (20%) on the basis of the PET results. Furthermore, in 14 cases (23.3%) with advanced disease, PET provided complete information on tumor spread, otherwise obtainable only by taking together the results of all other diagnostic procedures. Our data indicate a higher accuracy of FDG PET whole body scan compared to conventional imaging techniques in the evaluation of metastatic spread both at initial diagnosis and during follow-up, with an important impact on therapeutic decision-making. Moreover, by providing complete information on tumor spread in some cases, PET can become a profitable tool in terms of cost reduction.

FDG-PET in Thyroid Cancer

The most widely used diagnostic nuclear medicine technique in well-differentiated thyroid cancer (DTC) is radioiodine scintigraphy, either diagnostic or post-therapeutic, together with serum thyroglobulin (Tg) measurement; this combination is usually able to determine the presence or absence of cancer. FDG-PET has shown less sensitivity in DTC that retains the ability to trap 131I. Several alternative procedures with single photon emitting radiopharmaceuticals have been evaluated including whole body scan with 201TI, 99mTc-sestamibi or tetrofosmin scan, with different sensitivity and specificity. The main advantage of these tests is that their results are not influenced by the levels of TSH, therefore they do not require a hypothyroid state in the patient. Recently positron emission tomography (PET) with FDG has been demonstrated to be highly useful in thyroid cancer patients with a negative 131l whole body scan but measurable Tg. According to reports in the literature FDG-PET in the follow-up of operated patients has a sensitivity ranging from 70% to 90% in identifying the source of Tg. The demonstration of lesions can lead to a change in treatment including surgery or external radiation instead of radioiodine treatment. In Europe, medullary thyroid cancer (MTC) is currently visualized by 99mTc pentavalent dimercaptosuccinic acid (DMSA) and 99mTc-sestamibi or tetrofosmin. Metaiodobenzylguanidine (MIBG) radiolabeled with 123I or 131I is another reliable radiopharmaceutical for medullary tumors. 111In-pentetreotide scan is positive in a high percentage of patients because MTC expresses somatostatin receptors. FDG-PET has an interesting role to play in calcitonin-positive patients, where PET has been shown to correctly identify lesions in cervical and mediastinal lymph nodes as well as at distant sites. Furthermore, calcitonin-guided PET has been found to be superior to CT and MRI in many patients. Recent reports indicated that 18F-DOPA scan in MTC seems to be more accurate than FDG-PET.

Fast Quasi-Newton Algorithms for Penalized Reconstruction in Emission Tomography and Further Improvements via Preconditioning

This paper reports on the feasibility of using a quasi-Newton optimization algorithm, limited-memory Broyden-Fletcher-Goldfarb-Shanno with boundary constraints (L-BFGS-B), for penalized image reconstruction problems in emission tomography (ET). For further acceleration, an additional preconditioning technique based on a diagonal approximation of the Hessian was introduced. The convergence rate of L-BFGS-B and the proposed preconditioned algorithm (L-BFGS-B-PC) was evaluated with simulated data with various factors, such as the noise level, penalty type, penalty strength and background level. Data of three ¹⁸F-FDG patient acquisitions were also reconstructed. Results showed that the proposed L-BFGS-B-PC outperforms L-BFGS-B in convergence rate for all simulated conditions and the patient data. Based on these results, L-BFGS-B-PC shows promise for clinical application.

[State of the venous outflow from the small pelvis after surgical correction of pelvioperineal reflux]

OBJECTIVE

The study was aimed at assessing the venous outflow from the small pelvis after surgical correction of pelvioperineal reflux with the use of reference methods of examination.

PATIENTS AND METHODS

We examines a total of 43 female patients (aged 41.5±5.2 years) presenting with pelvic varicose veins and subjected to phlebectomy on the external genitalia, perineum and lower limbs. All women had no evidence of pelvic venous plethora. All women underwent the following examinations: ultrasonographic angioscanning of pelvic and lower-limb veins, emission computed tomography of pelvic veins prior to operation, as well as 1, 6 and 12 months after surgical interventions. We evaluated efficacy of phlebectomy in elimination of pelvioperineal reflux and varicose syndrome, the frequency of detecting valvular insufficiency of pelvic and lower-limb veins, dynamics of the coefficient of pelvic congestion syndrome in the immediate and remote postoperative periods.

RESULTS AND DISCUSSION

No cases of relapses of valvular, perineal varicosity, repeat appearance of varicose veins on the lower extremities, occurrence of signs of pelvic venous congestion were revealed. The frequency of detecting valvular insufficiency of the parametrial, uterine, gonadal and iliac veins remained unchanged. The coefficient of pelvic congestion syndrome did not alter either (Cpcs=0.8±0.11 at baseline versus Cpcs=0.78±0.1 after 12 months).

CONCLUSION

The obtained results are indicative of a steady state of the venous outflow from the small pelvis in women with pelvic varicose veins and pelvioperineal reflux after surgical removal of vulvar, perineal and superficial femoral veins.

Chinese Guideline for the Diagnosis and Treatment of Osteonecrosis of the Femoral Head in Adults

The treatment of adult osteonecrosis of the femoral head (ONFH), with 8.12 million patients in China, remains a challenge to surgeons. To standardize and improve the efficacy of the treatment of ONFH, Chinese specialists updated the experts' suggestions in March 2015, and an experts' consensus was given to provide a current basis for the diagnosis, treatment and evaluation of ONFH. The current guideline provides recommendations for ONFH with respect to epidemiology, etiology, diagnostic criteria, differential diagnosis, staging, treatment, as well as rehabilitation. Risk factors of non-traumatic ONFH include corticosteroid use, alcohol abuse, dysbarism, sickle cell disease and autoimmune disease and others, but the etiology remains unclear. The Association Research Circulation Osseous (ARCO) staging system, including plain radiograph, magnetic resonance imaging, radionuclide examination, and histological findings, is frequently used in staging ONFH. A staging and classification system was proposed by Chinese scholars in recent years. The major differential diagnoses include mid-late term osteoarthritis, transient osteoporosis, and subchondral insufficiency fracture. Management alternatives for ONFH consist of non-operative treatment and operative treatment. Core decompression is currently the most common procedure used in the early stages of ONFH. Vascularized bone grafting is the recommended treatment for ARCO early stage III ONFH. This guideline gives a brief account of principles for selection of treatment for ONFH, and stage, classification, volume of necrosis, joint function, age of the patient, patient occupation, and other factors should be taken into consideration.

[Hemato-oncological imaging : Importance of hybrid procedures]

CLINICAL/METHODICAL ISSUE

Biomedical imaging procedures play a major role in hemato-oncological diseases with respect to pre-therapeutic staging and assessment of treatment response.

STANDARD RADIOLOGICAL METHODS

Originally, the therapeutic management was the domain of computed tomography (CT) and whole-body magnetic resonance imaging (MRI).

METHODICAL INNOVATIONS

Over the last decade these purely morphological techniques have gradually been replaced by hybrid imaging techniques, such as positron emission tomography-CT (PET/CT) and PET/MRI, which also provide metabolic and functional information.

PERFORMANCE

For lymphomas, the PET tracer 18F-fluorodeoxyglucose (18 F-FDG) is meanwhile so well-established that its use is a cornerstone of the Lugano classification; however, for multiple myeloma the search for an optimal PET tracer that can also detect early disease stages is still ongoing. Functional MRI techniques, such as diffusion-weighted imaging (DWI), perfusion-weighted imaging and dynamic contrast-enhanced imaging have shown promising results for both lymphomas and multiple myelomas.

ACHIEVEMENTS

The PET/MRI technique can combine the different types of information due to its truly multiparametric approach.

PRACTICAL RECOMMENDATIONS

In the future PET/MRI could possibly become the hybrid imaging technique of choice for hemato-oncological diseases.

[Degenerative cerebellar diseases and differential diagnoses]

CLINICAL/METHODICAL ISSUE

Cerebellar syndromes result in distinct clinical symptoms, such as ataxia, dysarthria, dysmetria, intention tremor and eye movement disorders.

STANDARD RADIOLOGICAL METHODS

In addition to the medical history and clinical examination, imaging is particularly important to differentiate other diseases, such as hydrocephalus and multi-infarct dementia from degenerative cerebellar diseases. Degenerative diseases with cerebellar involvement include Parkinson's disease, multiple system atrophy as well as other diseases including spinocerebellar ataxia.

ACHIEVEMENTS

In addition to magnetic resonance imaging (MRI), nuclear medicine imaging investigations are also helpful for the differentiation.

PRACTICAL RECOMMENDATIONS

Axial fluid-attenuated inversion recovery (FLAIR) and T2-weighted sequences can sometimes show a signal increase in the pons as a sign of degeneration of pontine neurons and transverse fibers in the basilar part of the pons. The imaging is particularly necessary to exclude other diseases, such as normal pressure hydrocephalus (NPH), multi-infarct dementia and cerebellar lesions.

Multi-modality imaging: Bird's eye view from the 2016 American Heart Association Scientific Sessions

This review summarizes key imaging studies that were presented in the American Heart Association Scientific Sessions 2016 related to the fields of nuclear cardiology, cardiac computed tomography, cardiac magnetic resonance, and echocardiography. This bird's eye view will inform readers about multiple studies from these different modalities. We hope that this general overview will be useful for those that did not attend the conference as well as to those that did since it is often difficult to get exposure to many abstracts at large meetings. The review, therefore, aims to help readers stay updated on the newest imaging studies presented at the meeting.

Monitoring Disease Activity in Patients with Aortitis and Chronic Periaortitis Undergoing Immunosuppressive Therapy by Perfusion CT

RATIONALE AND OBJECTIVES

To evaluate the role of perfusion CT for monitoring inflammatory activity in patients with aortitis and chronic periaortitis undergoing immunosuppressive therapy.

MATERIALS AND METHODS

Seventeen symptomatic patients (median age 68.5 years) who underwent perfusion-based computed tomography (CT) monitoring after diagnostic contrast-enhanced CT were retrospectively included in this study. Blood flow (BF), blood volume (BV), volume transfer constant (k-trans), time to peak, and mean transit time were determined by setting circular regions of interest in prominently thickened parts of the vessel wall or perfused surrounding tissue at sites where the perfusion CT color maps showed a maximum BF value. Differences in CT perfusion and, morphological parameters, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) were tested for significance during therapy.

RESULTS

In all patients BF and BV dropped at second perfusion CT (P < 0.05). In aortitis patients, CRP dropped from 3.86 ± 5.31 mg/dL to 0.9 ± 1.37 mg/dL and in periaortitis patients from 1.78 ± 2.25 mg/dL to 0.79 ± 1.55 mg/dL, whereas ESR dropped from 45.71 ± 37.59 seconds to 8.57 ± 3.1 seconds and 36.78 ± 34.67 seconds to 17.22 ± 21.82 seconds in aortitis and in periaortitis, respectively.

CONCLUSIONS

The course of perfusion CT parameters in aortitis and chronic periaortitis undergoing immunosuppressive therapy dropped at different extent after therapy.

320-row CT renal perfusion imaging in patients with aortic dissection: A preliminary study

OBJECTIVE

To investigate the clinical value of renal perfusion imaging in patients with aortic dissection (AD) using 320-row computed tomography (CT), and to determine the relationship between renal CT perfusion imaging and various factors of aortic dissection.

METHODS

Forty-three patients with AD who underwent 320-row CT renal perfusion before operation were prospectively enrolled in this study. Diagnosis of AD was confirmed by transthoracic echocardiography. Blood flow (BF) of bilateral renal perfusion was measured and analyzed. CT perfusion imaging signs of AD in relation to the type of AD, number of entry tears and the false lumen thrombus were observed and compared.

RESULTS

The BF values of patients with type A AD were significantly lower than those of patients with type B AD (P = 0.004). No significant difference was found in the BF between different numbers of intimal tears (P = 0.288), but BF values were significantly higher in cases with a false lumen without thrombus and renal arteries arising from the true lumen than in those with thrombus (P = 0.036). The BF values measured between the true lumen, false lumen and overriding groups were different (P = 0.02), with the true lumen group having the highest. Also, the difference in BF values between true lumen and false lumen groups was statistically significant (P = 0.016), while no statistical significance was found in the other two groups (P > 0.05). The larger the size of intimal entry tears, the greater the BF values (P = 0.044).

CONCLUSIONS

This study shows a direct correlation between renal CT perfusion changes and AD, with the size, number of intimal tears, different types of AD, different renal artery origins and false lumen thrombosis, significantly affecting the perfusion values.

Multimodality-multiparametric brain tumors evaluation

Brain tumors represent a vast group of lesions, originating from different neuronal cells with different degrees of aggressiveness. Despite some technological advances either pre or post-treatment, these tumors may share similar imaging findings and properties, rendering diagnosis/prognosis, an ambiguous process. Gadolinium-enhanced magnetic resonance imaging remains the gold standard for providing detailed morphologic information, but presents several limitations due to the overlap of findings, in cases such as progressive tumor and post-radiation related effects. Tumor cellularity, vascularity, proliferative activity, metabolic and functional profiles are a few of many characteristics that may further support tumor classification, but cannot be assessed by conventional imaging alone. We review the aforementioned factors and indicate how they improve tumor characterization and grading in order to design the optimal treatment strategy and better evaluate post treatment efficacy.

The role of nuclear cardiac imaging in risk stratification of sudden cardiac death

Sudden cardiac death (SCD) represents a significant portion of all cardiac deaths. Current guidelines focus mainly on left ventricular ejection fraction (LVEF) as the main criterion for SCD risk stratification and management. However, LVEF alone lacks both sensitivity and specificity in stratifying patients. Recent research has provided interesting data which supports a greater role for advanced cardiac imaging in risk stratification and patient management. In this article, we will focus on nuclear cardiac imaging, including left ventricular function assessment, myocardial perfusion imaging, myocardial blood flow quantification, metabolic imaging, and neurohormonal imaging. We will discuss how these can be used to better understand SCD and better stratify patient with both ischemic and non-ischemic cardiomyopathy.

Endogenous Technology Adoption and Medical Costs

Despite the claim that technology has been one of the most important drivers of healthcare spending growth over the past decades, technology variables are rarely introduced explicitly in cost equations. Furthermore, technology is often considered exogenous. Using 1996-2007 panel data on Swiss geographical areas, we assessed the impact of technology availability on per capita healthcare spending covered by basic health insurance whilst controlling for the endogeneity of health technology availability variables. Our results suggest that medical research, patent intensity and the density of employees working in the medical device industry are influential factors for the adoption of technology and can be used as instruments for technology availability variables in the cost equation. These results are similar to previous findings: CT and PET scanner adoption is associated with increased healthcare spending, whilst increased availability of percutaneous transluminal coronary angioplasty facilities is associated with reductions in per capita spending. However, our results suggest that the magnitude of these relationships is much greater in absolute value than that suggested by previous studies that did not control for the possible endogeneity of the availability of technologies. Copyright © 2016 John Wiley & Sons, Ltd.

81-Fluorodeoxyglucose Positron Emission Tomography as a Novel Imaging Tool for the Diagnosis of Aortoenteric Fistula and Aortic Graft Infection

The diagnosis of aortic graft infection and aortoenteric fistula can be difficult to establish using conventional radiographic imaging modalities. Positron emission tomography (PET) imaging with 18-fluorodeoxyglucose (FDG) can rapidly provide anatomically clear images and define areas of inflammation with increased glucose metabolism. In this report the authors present a case of aortoenteric fistula diagnosed by FDG-PET. Early diagnosis led to rapid surgical intervention with graft removal and extraanatomic bypass. These encouraging results warrant larger controlled studies to evaluate the utility of FDG-PET in the diagnosis of prosthetic aortic graft infection.

The role and clinical effectiveness of multimodality imaging in the management of cardiac complications of cancer and cancer therapy

With the increasing number of individuals living with a current or prior diagnosis of cancer, it is important for the cardiovascular specialist to recognize the various complications of cancer and its therapy on the cardiovascular system. This is true not only for established cancer therapies, such as anthracyclines, that have well established cardiovascular toxicities, but also for the new targeted therapies that can have "off target" effects in the heart and vessels. The purpose of this informational statement is to provide cardiologists, cardiac imaging specialists, cardio-oncologists, and oncologists an understanding of how multimodality imaging may be used in the diagnosis and management of the cardiovascular complications of cancer therapy. In addition, this document is meant to provide useful general information concerning the cardiovascular complications of cancer and cancer therapy as well as established recommendations for the monitoring of specific cardiotoxic therapies.

Metabolic derangement in viable periinfarct tissue in the course of acute ischaemic infarction: a multitracer positron emission tomography (PET) study

We used a multitracer positron emission tomography (PET) approach to assess metabolic changes in infarcted and periinfarct tissue in acute ischaemic stroke. 16 patients were studied within 6-48 hours (mean, 23 h) after onset of symptoms from a first hemispheric stroke and again 13-25 days later (mean, 15.6 days). Regional cerebral metabolic rates of oxygen (CMRO2) and glucose (CMRGlc), blood flow (CBF) and blood volume (CBV) were measured and oxygen extraction (OEF) as well as glucose extraction (GEF) and microvascular transit time were calculated. PET images were three-dimensionally aligned using serial CT or MRI scans. Regions of interest on the side of the infarction were individually compared to contralateral mirror regions. In the infarction core CBF, CMRO2 and CMRGlc were significantly lower than on the contralateral side and did not change during time. In the periinfarct regions there was a decreased CMRO2 with progressive deterioration over time while CBF slightly increased. Only in a few ischaemic regions with initially increased OEF oxygen metabolism was preserved during the course of time.

Acetazolamide stimulation test in patients with unilateral internal carotid artery obstructions using transcranial Doppler and99mTC-HM-PAO-Spect

Fifteen patients with symptoms of cerebral ischaemia and angiographically confirmed unilateral stenoses or occlusions of the extracranial internal carotid artery (ICA) and 20 controls were studied by a 2 MHz transcranial Doppler (TCD) at rest and after stimulation with 1 g acetazolamide i.v., a cerebral vasodilator. In addition, the patients underwent 99mTc-HM-PAO-Spect measurement of regional cerebral blood flow (rCBF) at rest and after stimulation with 1 g acetazolamide. In 10 patients with ICA stenoses greater than 80% or occlusions, time-mean velocity (Vmean) increase and pulsatility index (PI) decrease in the postobstructive middle cerebral artery (MCA) as well as the increase of the ipsilateral rCBF were reduced in comparison with the contralateral side. The remaining 5 patients showed a normal Vmean increase and PI decrease in TCD.

Dynamic Infrared Imaging of Newly Diagnosed Malignant Lymphoma Compared with Gallium-67 and Fluorine-18 Fluorodeoxyglucose (FDG) Positron Emission Tomography

Staging and therapy monitoring of malignant lymphomas relies heavily on imaging using arbitrary size criteria from computed tomography (CT) and sometimes non-specific radionuclide studies to assess the activity of the disease. Treatment decisions are based on early assessment of the response to therapy and the residual volume of the disease. Our initial experience is reported using a new noninvasive, inexpensive, and reproducible passive imaging modality, Dynamic Infrared Imaging (DIRI), which may add a new dimension to functional imaging. This system relies on its ability to filter the raw infrared signal using biological oscillatory behavior. It detects and analyzes minute oscillations of temperature and heat distribution in tumors.

Optimization of Proton CT Detector System and Image Reconstruction Algorithm for On-Line Proton Therapy

The purposes of this study were to optimize a proton computed tomography system (pCT) for proton range verification and to confirm the pCT image reconstruction algorithm based on projection images generated with optimized parameters. For this purpose, we developed a new pCT scanner using the Geometry and Tracking (GEANT) 4.9.6 simulation toolkit. GEANT4 simulations were performed to optimize the geometric parameters representing the detector thickness and the distance between the detectors for pCT. The system consisted of four silicon strip detectors for particle tracking and a calorimeter to measure the residual energies of the individual protons. The optimized pCT system design was then adjusted to ensure that the solution to a CS-based convex optimization problem would converge to yield the desired pCT images after a reasonable number of iterative corrections. In particular, we used a total variation-based formulation that has been useful in exploiting prior knowledge about the minimal variations of proton attenuation characteristics in the human body. Examinations performed using our CS algorithm showed that high-quality pCT images could be reconstructed using sets of 72 projections within 20 iterations and without any streaks or noise, which can be caused by under-sampling and proton starvation. Moreover, the images yielded by this CS algorithm were found to be of higher quality than those obtained using other reconstruction algorithms. The optimized pCT scanner system demonstrated the potential to perform high-quality pCT during on-line image-guided proton therapy, without increasing the imaging dose, by applying our CS based proton CT reconstruction algorithm. Further, we make our optimized detector system and CS-based proton CT reconstruction algorithm potentially useful in on-line proton therapy.

Interventional Molecular Imaging

Although molecular imaging has had a dramatic impact on diagnostic imaging, it has only recently begun to be integrated into interventional procedures. Its significant impact is attributed to its ability to provide noninvasive, physiologic information that supplements conventional morphologic imaging. The four major interventional opportunities for molecular imaging are, first, to provide guidance to localize a target; second, to provide tissue analysis to confirm that the target has been reached; third, to provide in-room, posttherapy assessment; and fourth, to deliver targeted therapeutics. With improved understanding and application of(18)F-FDG, as well as the addition of new molecular probes beyond(18)F-FDG, the future holds significant promise for the expansion of molecular imaging into the realm of interventional procedures.

Navigational Bronchoscopy for Early Lung Cancer: A Road to Therapy

Peripheral lung nodules remain challenging for accurate localization and diagnosis. Once identified, there are many strategies for diagnosis with heterogeneous risk benefit analysis. Traditional strategies such as conventional bronchoscopy have poor performance in locating and acquiring the required tissue. Similarly, while computerized-assisted transthoracic needle biopsy is currently the favored diagnostic procedure, it is associated with complications such as pneumothorax and hemorrhage. Video-assisted thoracoscopic and open surgical biopsies are invasive, require general anesthesia and are therefore not a first-line approach. New techniques such as ultrathin bronchoscopy and image-based guidance technologies are evolving to improve the diagnosis of peripheral lung lesions. Virtual bronchoscopy and electromagnetic navigation systems are novel technologies based on assisted-computerized tomography images that guide the bronchoscopist toward the target peripheral lesion. This article provides a comprehensive review of these emerging technologies.

Role of Nuclear Medicine in the Diagnosis of Benign Thyroid Diseases

A deep understanding of thyroid pathophysiology is the basis for diagnosing and treating benign thyroid diseases with radioactive materials, known as radiopharmaceuticals, which are introduced into the body by injection or orally. After the radiotracer administration, the patient becomes the emitting source, and several devices have been studied to detect and capture these emissions (gamma or beta-negative) and transform them into photons, parametric images, numbers and molecular information. Thyroid scintigraphy is the only technique that allows the assessment of thyroid regional function and, therefore, the detection of areas of autonomously functioning thyroid nodules. Scintigraphy visualizes the distribution of active thyroid tissue and displays the differential accumulation of radionuclides in the investigated cells, thus providing a functional map. Moreover, this technique is a fundamental tool in the clinical and surgical management of thyroid diseases, including: single thyroid nodules with a suppressed thyroid-stimulating hormone level, for which fine-needle aspiration biopsy (FNAB) is used to identify hot nodules; multinodular goiters, especially larger ones, to identify cold or indeterminate areas requiring FNAB and hot areas that do not need cytologic evaluation, and to evaluate mediastinal extension; the diagnosis of ectopic thyroid tissue; subclinical hyperthyroidism to identify occult hyperfunctioning tissue; follicular lesions to identify a functioning cellular adenoma that could be benign, although such nodules are mostly cold on scintigraphy; to distinguish low-uptake from high-uptake thyrotoxicosis, and to determine eligibility for radioiodine therapy.

Adrenocortical Carcinoma Treated by CyberKnife

Adrenocortical carcinoma is a rare malignancy with a poor prognosis. The effective treatment for advanced cancer remains unknown. A 61-year-old woman underwent CyberKnife treatment on a large adrenocortical carcinoma and tumor emboli in both pulmonary arteries. Follow-up positron emission tomography scanning with fluorodeoxyglucose (FDG) revealed that the FDG uptake was greatly decreased in all the tumors, and the hormone levels were also decreased. CyberKnife is a safe and effective treatment option for the non-operative large advanced adrenocortical carcinoma.

Patient doses from CT examinations in Turkey

PURPOSE

We aimed to establish the first diagnostic reference levels (DRLs) for computed tomography (CT) examinations in adult and pediatric patients in Turkey and compare these with international DRLs.

METHODS

CT performance information and examination parameters (for head, chest, high-resolution CT of the chest [HRCT-chest], abdominal, and pelvic protocols) from 1607 hospitals were collected via a survey. Dose length products and effective doses for standard patient sizes were calculated from the reported volume CT dose index (CTDIvol).

RESULTS

The median number of protocols reported from the 167 responding hospitals (10% response rate) was 102 across five different age groups. Third quartile CTDIvol values for adult pelvic and all pediatric body protocols were higher than the European Commission standards but were comparable to studies conducted in other countries.

CONCLUSION

The radiation dose indicators for adult patients were similar to those reported in the literature, except for those associated with head protocols. CT protocol optimization is necessary for adult head and pediatric chest, HRCT-chest, abdominal, and pelvic protocols. The findings from this study are recommended for use as national DRLs in Turkey.

Enhancement patterns of intrahepatic mass-forming cholangiocarcinoma at multiphasic computed tomography and magnetic resonance imaging and correlation with clinicopathologic features

OBJECTIVE

Incidence of intrahepatic mass-forming cholangiocarcinoma (IMCC) is increasing worldwide, especially in patients with chronic liver disease. The small and the histologically well-differentiated IMCCs in chronic liver disease could be arterially hypervascular lesions with/without washout on computed tomography (CT) and magnetic resonance imaging (MRI), mimicking typical hepatocellular carcinoma (HCC). The aim of this work is to evaluate contrast enhancement (CE) patterns of IMCCs at quadri-phasic multidetector CT (4-MDCT) and MRI, using imaging-clinicopathologic correlation.

PATIENTS AND METHODS

The 4-MDCT and MR images of 56 histologically confirmed IMCCs were retrospectively evaluated for tumor morphology and enhancement features. Enhancement pattern was defined according to the behavior of the nodule in arterial (AP), portal venous (PVP) and equilibrium phases (EP), and dynamic pattern was described according to enhancement progression throughout the different phases. Arterial and dynamic enhancement patterns were correlated with chronic liver disease, tumor size and histological differentiation.

RESULTS

Most of the nodules were peripherally hyperenhancing (50%) on AP, and partially hyperenhancing on PVP (67.9%) and EP (80.3%). Forty-six (82.1%) IMCCs showed progressive CE, 7 (12.5%) stable CE and 3 (5.4%) wash-out. In normal liver there were 34 nodules with progressive and 3 with stable CE, whereas in chronic liver disease there were 12 IMCCs with progressive, 4 with stable and 3 with washout pattern (p = 0.01); IMCCs with progressive CE were more differentiated than IMCCs with stable CE and wash-out (p = 0.02).

CONCLUSIONS

The most prevalent enhancement pattern of IMCCs was arterial rim enhancement followed by progressive and concentric filling. The stable and the washout patterns were more frequent in poorly differentiated IMCCs. Contrast washout was observed only in IMCCs emerging in chronic liver disease with a risk of misdiagnosis with HCC.

Review of cardiovascular imaging in The Journal of Nuclear Cardiology in 2014: Part 2 of 2: Myocardial perfusion imaging

In this new feature of The Journal of Nuclear Cardiology we will summarize key articles that were published in the Journal in the previous year. In the first article of this 2-part series we concentrated on publications dealing with cardiac positron emission tomography, computed tomography, and neuronal imaging. This review will focus on myocardial perfusion imaging summarizing advances in the field including in diagnosis, prognosis, appropriateness, and safety of testing.

Extramedullary Soft Tissue Involvement and Discrepant Osseous Uptake on Tc-99m MDP and Ga-67 Citrate Scintigraphy in a Patient With Multiple Myeloma: A Case Report and Literature Review

Multiple myeloma (MM) is a plasma cell neoplasm with skeletal destruction which could also spread to extramedullary regions. Common diagnostic imaging modalities include skeletal radiography, computed tomography (CT), magnetic resonance imaging (MRI). Recently, PET/CT is proposed as an ideal tomographic tool for diagnosis and follow-up, but impending factors includes high cost, limited availability of cameras and radiotracers. Bone scan and gallium scan are usually considered of limited clinical value. Herein, we present a 66-year-old Taiwanese man with MM, who was hospitalized to our hospital for bone pain control. Bone and gallium scintigraphies were obtained for bone pain and infection workup. However, unexpected features of discordant osseous uptake with high gallium-to-bone uptake ratio and extramedullary gallium uptake were noted which both indicated poor prognosis of MM. The patient then passed away due to rapid disease progression. In conclusion, although gallium and bone scintigraphies are considered less sensitive for MM, combined use may be a good alternative for 18F-FDG PET/CT in evaluation of disease extent and prognosis, especially in high-risk patients or with suspicion of disease progression.

Factors determining renal impairment in unilateral ureteral colic secondary to calcular disease: a prospective study

OBJECTIVE

To evaluate all possible risk factors that can cause impairment of overall renal function in patients with unilateral ureteral calculus and a normal contralateral kidney.

METHODS

This is a prospective study of 90 patients who presented to our institute complaining of renal colic secondary to unilateral ureteral calculus. All patients were evaluated with a thorough history, physical examination, and laboratory and radiological investigations including renal function testing, urine analysis, non-contrast computed topography, and radionucleotide scan. Patients were divided into two groups according to their calculated creatinine clearance using the Modification of Diet in Renal Disease (MDRD) formula. Group I (favorable group) had a creatinine clearance >60 ml/min, while group II (unfavorable group) had a creatinine clearance <60 ml/min.

RESULTS

The patients' mean age ± SD was 38.8 ± 11.4 years. Group I included 54 patients (60 %), while group II included 36 patients (40 %). On univariate analysis, factors that were associated with overall renal function impairment were patients' age, urea-to-creatinine ratio (UCR), use of nonsteroidal anti-inflammatory drugs, stone location, and presence of obstruction. However, using binary logistic regression analysis, only patients' age, UCR, and presence of obstruction sustained statistical significance in association with renal function impairment.

CONCLUSION

The study of factors that help explain the presence of renal impairment in patients with unilateral ureteral calculus is important in the clinical setting. Patients' age, urea-to-creatinine ratio, and degree of obstruction seem to be significantly associated with overall renal function impairment.

Medical physicists' implication in radiological diagnostic procedures: results after 1 y of experience

Since January 2008-de facto 2012-medical physics experts (MPEs) are, by law, to be involved in the optimisation process of radiological diagnostic procedures in Switzerland. Computed tomography, fluoroscopy and nuclear medicine imaging units have been assessed for patient exposure and image quality. Large spreads in clinical practice have been observed. For example, the number of scans per abdominal CT examination went from 1 to 9. Fluoroscopy units showed, for the same device settings, dose rate variations up to a factor of 3 to 7. Quantitative image quality for positron emission tomography (PET)/CT examinations varied significantly depending on the local image reconstruction algorithms. Future work will be focused on promoting team cooperation between MPEs, radiologists and radiographers and on implementing task-oriented objective image quality indicators.

Functional MRI and CT biomarkers in oncology

Imaging biomarkers derived from MRI or CT describe functional properties of tumours and normal tissues. They are finding increasing numbers of applications in diagnosis, monitoring of response to treatment and assessment of progression or recurrence. Imaging biomarkers also provide scope for assessment of heterogeneity within and between lesions. A wide variety of functional parameters have been investigated for use as biomarkers in oncology. Some imaging techniques are used routinely in clinical applications while others are currently restricted to clinical trials or preclinical studies. Apparent diffusion coefficient, magnetization transfer ratio and native T1 relaxation time provide information about structure and organization of tissues. Vascular properties may be described using parameters derived from dynamic contrast-enhanced MRI, dynamic contrast-enhanced CT, transverse relaxation rate (R2*), vessel size index and relative blood volume, while magnetic resonance spectroscopy may be used to probe the metabolic profile of tumours. This review describes the mechanisms of contrast underpinning each technique and the technical requirements for robust and reproducible imaging. The current status of each biomarker is described in terms of its validation, qualification and clinical applications, followed by a discussion of the current limitations and future perspectives.

[Clinical value of the ECT bone scan in diagnosis of prosthesis infection for revision]

OBJECTIVE

To detect the clinical value of the ECT bone scan in evaluating of the situation of infection control after hip knee arthroplasty.

METHODS

The clinical data were retrospectively analyzed in 62 patients, including 34 males and 28 females with an average age of 68.8 years old ranging from 65 to 74 years. The results of ECT bone scan, erythrocyte sedimentation rate, C-reactive protein were used to assess periprosthetic infection. The patients with positive ECT and ESR on CRP were considered to have periprosthetic infection; however, the patients with two or more negative, indexes were considered to have no infection.

RESULTS

The sensitivity, specificity, accurate rate of ECT were 75.0%, 88.9%, 87.1% respectively; ESR 50.0%, 72.2%, 69.4%; CRP 62.5%, 81.4%, 79.0%. The combination of the three methods were 87.5%, 96.3% and 95.2%,

CONCLUSION

Compared with ESR and CRP, ECT is a more effective way in the diagnosis of periprosthetic infection, which has great value and is worth popularizing.

Systemic treatment of advanced differentiated and medullary thyroid cancer. Overview and practical aspects

In the last few years, three new drugs for targeted systemic therapies have been approved for advanced and progressive thyroid cancer, namely vandetanib and cabozantinib for medullary and sorafenib for radioiodine refractory differentiated thyroid cancer. Patient selection by an interdisciplinary team and education of patients by the treating physicians play a major role when such a treatment is considered and initiated. Only patients with significant tumor burden and/or symptomatic disease or progression, which cannot be controlled by local therapies, should be treated. In order to preserve quality of life, the management of adverse effects is of utmost importance. Due to the mechanism of action of these tyrosine kinase inhibitors, the reliability of serum tumour markers, calcitonin and thyroglobulin, is limited for the assessment of response and follow-up, therefore morphological and metabolic imaging is of great importance. Minor or localized progression should not automatically trigger the termination of treatment or change of drug. In the near future, it is expected that additional drugs become available.