Detection Of Focal Lesions Research Articles

Subspecialty Second-Opinion in Multiple Myeloma CT: Emphasis on Clinically Significant Lytic Lesions.

Background and objectives: In order to increase the accuracy of lytic lesion detection in multiple myeloma, a dedicated second-opinion interpretation of medical images performed by subspecialty musculoskeletal radiologists could increase accuracy. Therefore, the purpose of this study is to evaluate the added value (increased accuracy) of subspecialty second-opinion (SSO) consultations for Computed Tomography (CT) examinations in Multiple Myeloma (MM) patients undergoing stem cell transplantation on standard computed tomography with a focus on focal lesion detection. Materials and Methods: Approval from the institutional review board was obtained. This retrospective study included 70 MM consecutive patients (mean age, 62 years ± 11.3 (standard deviation); range, 35–88 years) admitted in the last six years. Pre-transplant total-body CT (reported by general radiologists) was the only inclusion criteria. Each of these CT examinations had a second-opinion interpretation by two experienced subspecialty musculoskeletal (MSK) radiologists (13 years of experience and 6 years of experience, mean: 9.5 years), experts in musculoskeletal radiology and bone image interpretation with a focus on lytic lesions. Results: Per lesion intra- and inter-observer agreement between the two radiologists was calculated with K statistics and the results were good (K = 0.67: Confidence Inteval (CI) 95%: 0.61–0.78). When the initial CT reports were compared with the re-interpretation reports, 46 (65%) of the 70 cases (95% CI: 37–75%) had no discrepancy. There was a discrepancy in detecting a clinically unimportant abnormality in 10/70 (14%) patients (95% CI: 7–25%) unlikely to alter patient care or irrelevant to further clinical management. A discrepancy in interpreting a clinically important abnormality was registered in 14/70 (21%) patients for focal lesions. The mean diameter of focal lesions was: 23 mm (95% CI: 5–57 mm). The mean number of focal lesions per patient was 3.4 (95% CI). Conclusions: subspecialty second-opinion consultations in multiple myeloma CT is more accurate to identify lesions, especially lytic lesions, amenable to influence patients’ care.

The role of MRI in Detection and Characterization of Benign Hepatic Focal Lesions

Abstract Background The benign and malignant hepatic foci are a common disease in recent times. The most benign lesions are in non cirrhotic liver. The main goals of MRI liver techniques are detection and characterization of equivocal hepatic focal lesions with indeterminate results by other diagnostic modalities e.g. US or CT. Aim of the Study to describe the role of MRI in early detection and characterization of benign Hepatic focal lesions. Using unenhancement, contrast enhancement and diffusion weighted MR images; for better patient management plan. Patients and Methods This study conducted on 25 patients; four patients of them have 2 different HFL, suspicion of Hepatic focal lesions on the basis of US and/or CT. The study took place at Ain Shams University hospital. Results Present study revealed that maximum percentage of MRI finding in benign HFL is Hemangioma (37.93%) followed by Simple hepatic cyst (27.59%). The most common benign HFL are low signal intensity in T1 precontrast study and the most common benign HFL are High signal intensity in T2 precontrast study. Also, the most benign HFL show no restriction diffusion. Conclusion Benign hepatic focal lesions are frequently encountered in clinical practice and their characterization may be sometimes difficult. Magnetic resonance imaging MRI has more advantages than ultrasound, computed tomography CT in diagnosing and characterization of focal hepatic masses. With a combination of basic T1 and T2 weighted sequences, diffusion weighted imaging DWI, and use of contrast agents, most liver lesions can be adequately diagnosed.

Role of diffusion weighted MRI in differentiation between benign and malignant hepatic focal lesions

Abstract Background Magnetic resonance imaging (MRI) is playing an increasing role in the assessment of patients with liver disease due to its high soft tissue resolution, lack of ionizing radiation and ability to provide functional data. Diffusion-weighted (DW)-MRI is a functional imaging technique that is now widely used as a standard imaging sequence, together with unenhanced T1/T2 weighted imaging and contrast-enhanced imaging for liver evaluation. Objective The aim of this study is to clarify the role of Diffusion Weighted Magnetic Resonance Imaging (DW MRI) in the detection of hepatic focal lesions and its ability to differentiate benign from malignant hepatic focal lesions. Patients and Methods This study carried out in Radiology Department of Ain Shams University Hospitals. This study included 25 patients. All patients were subjected to careful history taking, abdominal US, laboratory examinations, and liver MRI. Result The difference between the mean ADC values of benign and malignant lesions was significant. No significant differences in ADC values among the different benign lesions or among the different malignant lesions. Conclusion Diffusion-weighted imaging (DWI) offers the possibility to obtain criteria for characterization of focal liver lesions with subsequent differentiation between benign and malignant hepatic focal lesions without the need for contrast agent administration-by quantifying diffusion effects via apparent diffusion coefficient (ADC) measurements.

Intraoperative ultrasound in visceral surgery

Intraoperative ultrasound is aroutine procedure in abdominal surgery. Not only detection of focal lesions but also perfusion and elasticity analyses using color-coded Doppler sonography, contrast-enhanced ultrasound and elastography enable highly sensitive and highly specific diagnostics, especially in oncological surgery. This article provides an overview on current techniques of intraoperative ultrasound and gives an outlook on future possibilities and applications. Literature-based presentation of evidence-based intraoperative ultrasound, discussion of current basic research and expert recommendations. Modern intraoperative ultrasound is ahighly efficient technique for detection and characterization of focal space-occupying lesions in surgery of benign and malignant diseases. Intraoperative ultrasound is ahighly sensitive and specific diagnostic tool, providing real-time diagnostics with a manageable amount of technical equipment. Thus, preoperative diagnostics can be refined, partly resulting in amodification of intraoperative treatment management. Future developments in the fields of digital image fusion with preoperative sectional imaging, optical guidance of surgical instruments and molecular targeted tumor therapy will increase the importance of intraoperative sonography even more.

Comparison of image quality and focal lesion detection in abdominopelvic CT: Potential dose reduction using advanced modelled iterative reconstruction

PurposeTo evaluate radiation dose exposure, diagnostic performance, and image quality of low-dose and ultralow-dose abdominopelvic CT using the advanced modelled iterative reconstruction (ADMIRE) algorithm for focal lesion detection. MethodsOne hundred thirty-nine consecutive patients underwent contrast-enhanced abdominopelvic CT using a third-generation dual-source scanner to obtain three data sets with the following tube loads: 33.3% (ultralow-dose CT), 66.7% (low-dose CT), and 100% (standard-dose CT). The diagnostic performances of standard-dose CT, low-dose CT, and ultralow-dose CT for focal lesion detection and characterization in organs of the abdominopelvic cavity were analyzed by two readers and compared with the reference standard. Image quality was measured subjectively and objectively. ResultsFocal lesion detection showed 96.5–100% sensitivity and 97.7–100% accuracy in all representative organs on low-dose CT with acceptable image quality; it showed 87.4% sensitivity and 97.9% accuracy in the liver and 80.0% sensitivity and 88.2% accuracy in the rectal shelf on ultralow-dose CT with suboptimal image quality. Indeterminate lesions were significantly more common in the liver, pancreas, and kidneys on ultralow-dose CT than on low-dose CT. Enlarged lymph nodes showed 100% sensitivity and accuracy on ultralow-dose CT. Mean effective radiation doses of low-dose CT and ultralow-dose CT were 2.6 mSv and 1.3 mSv, respectively. ConclusionsThe diagnostic performance of low-dose CT is similar to that of standard-dose abdominopelvic CT with acceptable image quality. Ultralow-dose CT cannot safely assess focal liver, pancreas, kidneys, and rectal shelf lesions but may be useful for the evaluation of enlarged lymph nodes.

FDG-PETCT versus contrast-enhanced computed tomography in diagnosis of post-therapeutic colorectal cancer recurrence and metastases

BackgroundThis study was designed to assess the role of 18F-FDG CT was able to detect additional/CT in post-therapeutic surveillance of colorectal cancer patients as compared with contrast-enhanced CT to allow early detection of recurrent and metastatic cases amenable for curative surgery and thus improve the overall survival of patients.ResultsOf the total 100 patients, 70 proved to have metastasis or local recurrent disease by the standard reference modalities. One hundred eighty-two diseased regions were detected in these 70 patients. PET/CT was positive in 174 regions (95.6%) whereas CECT was positive in 118 regions (64.8%). PET/CT was superior to CECT in detection of hepatic focal lesions, metastatic lymph nodes, pulmonary metastases, and peritoneal and suprarenal metastases whereas both were equal in detection of osseous deposits. CECT detected four lesions that were missed by PET/CT, and these were hepatic metastases from mucinous adenocarcinoma.ConclusionPET/CT is a better method to evaluate post-therapeutic colorectal cancer patients. It detected viable residual tumor cells in operative bed scar, small LNs, hepatic focal lesions, peritoneal deposits, pulmonary masses, bone deposits, and suprarenal deposits with significantly higher specificity and sensitivity than CECT avoiding unnecessary surgeries.

Does MRI diffusion help in the detection and characterization of benign and malignant hepatic focal lesions in the nonpediatric age group?

Introduction Liver MRI has been used in cases where ultrasound or computed tomography findings are equivocal. Diffusion-weighted imaging (DWI) established an important role in clinical use in the liver. DWI can potentially add useful information to conventional imaging. Objective The aim was to assess the role of DWI in the detection and characterization of hepatic focal lesions and its value to differentiate benign from malignant masses. Patients and methods The study included 40 patients, 19 women and 21 men, their ages ranged from 20 to 63 years. All patients underwent detailed MRI study of the abdomen. Diffusion study was performed with tridirectional diffusion gradients using b values 0, 500, and 1000 s/mm2 to increase the sensitivity. Apparent diffusion coefficient (ADC) maps and values were calculated for all lesions. Results In all, 20 patients were diagnosed to have benign lesions and 20 patients were diagnosed to have malignant lesions. Hemangiomas and cysts showed facilitated diffusion while adenomas show restricted diffusion pattern mimicking malignant focal lesions. On the other hand, all malignant lesions showed restricted diffusion evidenced by increased signal on increasing the b values and low signal on ADC maps. Mostly benign lesions show higher ADC values than malignant lesions. Conclusion Diffusion-weighted MRI sequence with quantitative ADC measurements should be used as an additional sequence to supplement conventional MRI protocol studies for proper characterization of focal hepatic lesions putting into consideration an overlap range.

Maximizing FDG-PET/CT Utility in Staging of Follicular Lymphoma (FL): The Role of Spleen Involvement and Bone Standardized Uptake Values

Background: FDG PET/CT and bone marrow biopsy (BMB) are considered standard procedures for the staging of patients with new, untreated FL. A key issue in FL is the early identification of patients who will fail early. We recently reported (Am J Hematology 2019) that the presence of ≥2 EN sites, spleen, bone or soft tissue involvement as detected by PET all predicted failure to achieve EFS24. In Hodgkin lymphoma and diffuse large B-cell NHL, PET has replaced the routine need for a staging BMB. However, there is no such evidence in FL. The goal of this study was to determine the value of FDG PET/CT in determining bone involvement in FL using BMB as the gold standard. Methods: Patients were identified using the Mayo Clinic Lymphoma Database. 548 patients with newly diagnosed FL grades 1-3A between years 2003-2016, available BMB results, and PET/CT imaging at diagnosis, were included in the analysis. The presence of bone and spleen involvement on PET/CT, SUVmax and SUVmean of the axial skeleton at L3, and BMB results were recorded and compared. Results: In all, 36% (197/548) of patients had a positive BMB, and 34% (189/548) had bone involvement detected on PET/CT. Compared to BMB, the sensitivity and specificity of PET/CT in detecting bone involvement as determined by BMB were 60% and 80%, respectively. We noted that 59 patients had focal bone involvement on PET/CT rather than a diffuse component, and found that 47% (28/59) of these patients had a negative BMB obtained in the posterior iliac crest. Excluding these patients, the sensitivity and specificity of PET/CT in detecting bone involvement were 53% and 88%, respectively (Table 1). With respect to the spleen, 29% (157/548) of patients had evidence of splenic FL involvement on PET/CT, and of these, 69% (109/157) also had a positive BMB. The sensitivity and specificity of spleen involvement on PET/CT in predicting bone involvement on BMB were 55% and 86%, respectively (Table 2). We recorded SUV data at L3 in the 439 patients who had either a diffuse pattern of bone involvement on PET/CT, or a PET/CT read as negative. We analyzed the positive and negative predictive values (PPV and NPV) of SUVmax and SUVmean at several cut-off points to determine whether axial bone SUV is reliable at determining patients with a positive or negative BMB. The NPV for an SUVmax of less than 2.0 was 96% (n=25 patients classified as negative). For SUVmean, the best cut-off point was at less than 1.4, where NPV was 100% (n=15 patients classified as negative). There was no logical cut-off point for a significant PPV > 95%. Conclusion: In newly diagnosed FL, the sensitivity and specificity of bone involvement on PET/CT are insufficient for PET/CT to routinely replace BMB. However, in patients where the need for BMB at staging is being debated, certain factors on PET/CT can help facilitate this decision. The detection of focal bone lesions, especially those that may be missed on posterior iliac crest BMB, can make BMB unnecessary. If both the spleen and bone appear involved on PET/CT, this confers a relatively high chance that BMB will be positive. If SUVmax at L3 is less than 2.0, or if SUVmean is less than 1.4, the BMB will likely be negative, with a NPV > 95%. This decision-making algorithm is outlined in Figure 1 and may serve as a useful guideline for clinical trials and routine practice. Disclosures No relevant conflicts of interest to declare.

Whole Body Diffusion Weighted MRI (WB DWI) for the Management of Multiple Myeloma: High Concordance between MRI Diffuse Pattern and BONE Marrow Plasma CELL Infiltration RATE

Background: Diffusion-weighted whole body MRI (WB-DWI) is a new functional imaging technique comprising anatomical and functional sequences with an emerging role in the management of multiple myeloma (MM) patients (pts) since it allows highly sensitive detection of diffuse bone marrow (BM) infiltration pattern and focal lesions, avoiding intravenous injections and radiation exposure. The aims of our study were 1) to test the correlation between plasma cells infiltration (BMPC) rate at BM biopsy and the presence of diffuse infiltration pattern at WB-DWI. 2) to compare response according to IMWG criteria and WB-DWI response and to establish the rate of discordancy (WB-DWI progression with increased focal lesions and at least a partial response according to IMWG criteria) Methods: We reviewed data regarding 45 MM patients (pts) observed in our Centre between September 2018 and July 2019 for whom quantification of serum and urine monoclonal component (MC), free light chains value (FLC), BM biopsy, whole body CT scan and WB-DWI data were available at the same time point. Sequential assessment of WB-DWI and laboratory data was available in 20 pts. Patients performed a WB-DWI (Magnetom Area, 1.5T, Siemens Enlarged Germany) for head to knee. The protocol included anatomical sequences T1 and T2 weighted with fat suppression on the sagittal plane specifically for the spine. Coronal T2 weighted fat suppression sequences are performed for the study of femural bone. Axial Dixon T1 weighted sequences of the whole scan region, in breath-old. The functional part is formed by diffusion weighted sequences in the axial plane. MM diagnosis and response were assessed by IMWG criteria. Response were categorized as follows: responsive patients if ≥PR, progressive disease if <PR. BM infiltration rate was used as a continuous variable. WB-DWI findings at first evaluation were categorized as follows: presence/absence of focal lesions, presence/absence of diffuse pattern of BM infiltration. Radiological re-assessment of both focal lesions and diffuse pattern was categorized as follows: reduced/stable/increased. Discordant pattern of progression was defined as: ≥PR + diffuse pattern stable/reduced + focal lesions increased. Association between two categorical variables was evaluated by Fisher's exact test. Mann-Whitney test was used to compare a quantitative variable among two independent groups of patients. P-values<0.05 were considered significant. Results: Table 1 summarizes the clinical and radiological data of the population on study. Median age was 64 years (range 38-86), median number of previous lines of therapy at time of evaluation was 0 (range 0-)2; 47% pts were at the onset, 31% were in follow-up after treatment completion, 22% had progressive disease. WB-DWI showed a diffuse pattern in 22 pts (49%); in 23 patients without a diffuse pattern, 7 (30%) had PBMC >10%; BMPC infiltration rate was significantly higher in pts with presence of diffuse pattern at WB-DWI (p<0.001; Figure 1). WB-DWI showed focal lesions in 35 pts (78%): 19 of them were at onset of disease. Most of the patients performing sequential assessment of WB-DWI were responsive according to IMWG criteria at time of WB-DWI re-evaluation (17 pts with ≥PR, 85%). Table 2 shows radiological findings according to IMWG response. Focusing on patients with ≥PR, WB-DWI diffuse pattern was reduced in 13 pts (76.5%) and stable in 4 pts (23.5%) with complete concordance between hematological and radiological findings (increased diffuse pattern in no pt with ≥PR); focal lesions were reduced in 76.5% and increased in 23.5%; a discordant pattern of progression was found in 4 patients (20%). Conclusions: Our study findsa significant correlation between presence of WB-DWI diffuse infiltration patter and BMPC rate, highlighting the possible future use of this radiological technique for monitoring BM residual disease. In addition, this study shows the possible not negligible emergence of discordant pattern of progression, probably deriving from the spatial heterogeneity of MM clones and their different sensitivity to therapy. Disclosures Mangiacavalli: celgene: Consultancy; Janssen cilag: Consultancy; Amgen: Consultancy. Varettoni:Gilead: Other: travel expenses; ABBVIE: Other: travel expenses; Roche: Consultancy; Janssen: Consultancy. Arcaini:Celgene: Speakers Bureau; Celgene, Roche, Janssen-Cilag, Gilead: Other: Travel expenses; Gilead Sciences: Research Funding; Bayer, Celgene, Gilead Sciences, Roche, Sandoz, Janssen-Cilag, VERASTEM: Consultancy.

Automatic detection and localization of Focal Cortical Dysplasia lesions in MRI using fully convolutional neural network

Focal cortical dysplasia (FCD) is the leading cause of drug-resistant epilepsy in both children and adults. At present, the only therapeutic approach in patients with drug-resistant epilepsy is surgery. Hence, the quantification of FCD via non-invasive imaging techniques helps physicians to decide on surgical interventions. The properties like non-invasiveness and capability to produce high-resolution images makes magnetic resonance imaging an ideal tool for detecting the FCD to an extent. The FCD lesions vary in size, shape, and location for different patients and make the manual detection time consuming and sensitive to the experience of the observer. Automatic segmentation of FCD lesions is challenging due to the difference in signal strength in images acquired with different machines, noise, and other kinds of distortions such as motion artifacts. Most of the methods proposed in the literature use conventional machine learning and image processing techniques in which their accuracy relies on the trained features. Hence, feature extraction should be done more precisely which requires human expertise. The ability to learn the appropriate features/representations from the training data without any human interventions makes the convolutional neural network (CNN) the suitable method for addressing these drawbacks. As far as we are aware, this work is the first one to use a CNN based model to solve the aforementioned problem using only MRI FLAIR images. We customized the popular U-Net architecture and trained the proposed model from scratch (using MRI images acquired with 1.5T and 3T scanners). FCD detection rate (recall) of the proposed model is 82.5 (33/40 patients detected correctly).

Septic cerebral thrombosis in neonates: A case report and review of the literature

Introduction: Septic dural-sinus thrombosis is rare; it is one of the most misdiagnosed conditions of our time. It is often associated with a high level of mortality. Especially in neonates who have an underdeveloped immune system and haphazard clinical manifestation. Septic sinus thrombosis frequently involves cavernous sinuses. The superior sagittal sinuses’ involvement is exceptional as it is often associated with a fatal outcome. Studies demonstrate that heparin therapy in sagittal sinus septic thrombosis is unnecessary and that the focus of treatment shall be intravenous antibiotics and early surgical drainage of purulent collections who can be a source of widespread infections. Case Report: We report the case of a three months old boy, without pathological history, admitted in the intensive care unit (ICU) for febrile convulsion resistant to first line therapy. Cerebrospinal fluid analysis results were in favor of pneumococcus pathogens. Cerebral computed tomography (CT) has shown a superior longitudinal sinus thrombophlebitis complicating an encephalitis, with multiple venous infarcts. After which antibiotherapy was changed and anticoagulation added. Six days later, the sedation was stopped to evaluate the neurological state. The patient has shown a persistence of the coma state. After a multidisciplinary discussion, a transcranial Doppler was realized only to confirm the brain death state. The evolution was marked by the death of the patient after three days. Conclusion: In general, cerebral venous thrombosis (CVT) is a disease with complex clinical manifestations, atypical in many patients. If an alteration of consciousness is the main symptom in a CVT patient, the prognosis can be bleak. Most patients with CVT have a good prognosis after early anticoagulant and antibiotherapy. Since cerebral hernia is the most common cause of death in CVT, intensive care should be given special attention to the detection and treatment of focal lesions occupying space.

Role of MDCT in Detection and Characterisation of Focal Liver Lesions

Role of MDCT in Detection and Characterisation of Focal Liver Lesions

Sonography of splenic tumors: The almost forgotten organ in abdominal US examination

Although examination of the spleen is routinely included in the general abdominal gray-scale ultrasound (US) study, it was considered of limited use in the past and was performed almost only to distinguish between cystic and solid lesions. In the last two decades due to accumulated experience and the introduction of second-generation contrast agents, this technique has been re-evaluated as contrast-enhanced US (CEUS) allows detection and characterization of most focal lesions of the spleen with a high sensitivity and a good specificity. US can provide a correct diagnosis in simple cysts, whereas CEUS is useful when cystic lymphangioma is suspected. US presents a low specificity and relatively low sensitivity in splenic infarctions, while CEUS can achieve a high specificity (up to 100 %). There is a wide spectrum of benign and malignant neoplasms of the spleen. Lymphomas and vascular tumors comprise the most common splenic neoplasms. Splenic hemangiomas and angiosarcomas are the most common mesenchymal tumors in which US and CEUS may show characteristic imaging findings and permit precise diagnosis. US-guided fine needle aspiration and/or biopsy of focal splenic lesions are being increasingly performed to obtain tissue for histopathological characterization. Accurate diagnosis of focal splenic lesions allows institution of optimal patient management. In the study of splenic lesions, the most important problem is to differentiate between angioma, hamartoma, lymphoma, and metastasis. CEUS presents a high specificity in the differentiation of benign and malignant splenic lesions, as hypoenhancement in the parenchymal phase is suggestive of malignancy in 87 % of cases. US, as compared to CT and MRI, has certain advantages, including its ubiquitous availability, lack of ionizing radiation, and low cost, and with additional application of CEUS, can be widely indicated in the study of focal splenic lesions.

Significance of posterior acoustic enhancement ultrasonographic findings in the diagnosis of hepatocellular carcinoma

Introduction. On ultrasound, hepatocellular carcinoma presents with nodular or multinodular lesions of different size and echostructure, sometimes with a surrounding halo, and lateral acoustic shadows or posterior acoustic enhancement. The aim of this study was to determine the incidence of posterior acoustic enhancement in hepatocellular carcinoma. Material and Methods. This retrospective study included 120 patients with pathologically verified hepatocellular carcinoma who had undergone ultrasound examination (using real time ultrasounds from different manufacturers, with 3.5 and 5 MHz probes). Ultrasound imaging focused on the size and appearance of the focal lesions, i. e. echostructure and presence or absence of posterior acoustic enhancement as areas of increased echogenicity behind the lesion. Results. Posterior acoustic enhancement was observed in 47.3% of all nodular hepatocellular carcinomas, whereas this ultrasound phenomenon was statistically significantly more common in the group of tumors from 3 to 5 cm in size. In the group of multinodular tumors, posterior acoustic enhancement was found in 70% of cases. Conclusion. The presence of posterior acoustic enhancement in the detection of focal hepatic lesions may be a significant finding in the diagnosis of hepatocellular carcinoma, especially in patients at risk for developing hepatocellular carcinoma (cirrhosis and chronic liver disease), as well as in monitoring interval growth in size of focal lesions using this ultrasound phenomenon.

Role of Positron Emission Tomography/Computed Tomography in Evaluation of Hepatic Focal Lesions

AbstractBackground: Positron Emission Tomography/Computed Tomography (PET/CT) has emerged as an increasingly im-portant functional diagnostic tool of various primary or metastatic cancers. PET/CT provides unique information with combined anatomical localization and the metabolic activity of the lesion. In contrast to morphological imaging techniques the 18F-flurodeoxyglucose (FDG) PET evaluates tumor via-bility based on glucose metabolism. By far the most extensive use of PET/CT imaging to date has been in the diagnosis, staging, follow-up and monitoring of malignancies.Aim of Study: The aim of this study was to evaluate the efficiency of PET/CT in the detection and characterization of hepatic focal lesions.Patients and Methods: Twenty patients were referred with hepatic focal lesions based on previous imaging modalities or histopathological examination who underwent combined PET/CT. Detailed retrograde lesion based and patient based analyses were performed for 84 detected hepatic lesions in 20 patients.Results: PET/CT showed sensitivity of 92.42% and spe-cificity of 83.33% in detection of various hepatic focal lesions and higher sensitivity of 100% and specificity of 100% in detection of hepatic metastases from different primaries. Also, PET/CT showed sensitivity of 95.31% in detection of malignant lesions and sensitivity of 75% in detection of benign lesions. So, PET/CT was useful to differentiate malignant from benign lesions in the liver.Conclusion: FDG PET/CT proved to be highly sensitive and specific in the assessment of hepatic focal lesions and was able to differentiate between malignant and benign hepatic focal lesions and their metabolic nature which significantly affect further management.

Subsequent experience in hybrid PET-MRI for evaluation of refractory focal onset epilepsy

PurposeEpilepsy surgery is the most successful method of treating medically unresponsive epilepsy, but carries a risk of morbidity. PET/MR is an emerging technique that increases detection of focal lesions whose resection may result in symptom remission. MethodsRetrospective review of 74 focal epilepsy patients over a period of 3 years who had a PET/MR was performed following IRB permission and informed consent. 27 patients underwent surgery or RNS (responsive neurostimulator) placement. ResultsHybrid PET-MR identified new anatomic or functional lesions in 10 patients not identified with standalone 3 T MR. Of the 27 patients who underwent focal surgery (19) or RNS placement (8), 24 showed improvement (Engel’s I-III), 2 did not (Engel’s IV), and one had an RNS explanted due to infection. MR and PET were read by 2 separate neuroradiologists and nuclear medicine physicians, respectively. Modalities were evaluated in terms of ability to detect the correct lobe and side for a focal lesion whose resection improved symptoms. Prior standalone MR exhibited 71–77% sensitivity and 0% specificity (as there were only 2 nonresponders), MR associated with PET/MR had 68–71% sensitivity and 0–50% specificity (depending on whether a lesion was seen on one of the nonresponders), and PET had 68–71% sensitivity and 25–33% specificity. Using either PET or MR to identify a focal lesion, PET/MR had sensitivity of 78–82% and specificity 0–50%. ConclusionsPET-MR provides additional sensitivity when used as two combined modalities for detecting possible epileptic foci.

Voxel-based automated detection of focal cortical dysplasia lesions using diffusion tensor imaging and T2-weighted MRI data

The aim of this study was to automatically detect focal cortical dysplasia (FCD) lesions in patients with extratemporal lobe epilepsy by relying on diffusion tensor imaging (DTI) and T2-weighted magnetic resonance imaging (MRI) data. We implemented an automated classifier using voxel-based multimodal features to identify gray and white matter abnormalities of FCD in patient cohorts. In addition to the commonly used T2-weighted image intensity feature, DTI-based features were also utilized. A Gaussian processes for machine learning (GPML) classifier was tested on 12 patients with FCD (8 with histologically confirmed FCD) scanned at 1.5 T and cross-validated using a leave-one-out strategy. Moreover, we compared the multimodal GPML paradigm's performance with that of single modal GPML and classical support vector machine (SVM). Our results demonstrated that the GPML performance on DTI-based features (mean AUC = 0.63) matches with the GPML performance on T2-weighted image intensity feature (mean AUC = 0.64). More promisingly, GPML yielded significantly improved performance (mean AUC = 0.76) when applying DTI-based features to multimodal paradigm. Based on the results, it can also be clearly stated that the proposed GPML strategy performed better and is robust to unbalanced dataset contrary to SVM that performed poorly (AUC = 0.69). Therefore, the GPML paradigm using multimodal MRI data containing DTI modality has promising result towards detection of the FCD lesions and provides an effective direction for future researches.

The Role of Diffusion Weighted MRI in the Differentiation between Benign and Malignant Hepatic Focal Lesion

Background: early detection and diagnosis of hepatic focal lesions are an important step in clinical work, which would allow effective surgical or mini-invasive therapy. With the advances in magnetic resonance imaging (MR) technology, diffusion-weighted magnetic resonance imaging (DWI) is now widely used as a standard imaging sequence in clinical work and shows its potential benefit in evaluation of the focal hepatic lesions. Aim of the work: the use of MR Diffusion imaging with both low and high B values to detect and differentiate between benign and malignant hepatic focal lesion. Methodology: the present study included 30 patients. They were El-Demerdash hospital patients with hepatic focal lesions. Patients underwent US or CT before MR examination. Results: thirty patients were included in this study, 20 males and 10 females. The patient’s age was ranging from 33 to 60 years. There were 24 primary hepatic focal lesions, (36.7% HCC, 3.3% focal nodular hyperplasia, 3.3% cysts, 13.3% hemangiomas, 6.7% cholangiocarcinoma, 16.7% regeneration nodule) and 6 metastatic lesions. Conclusion: we hope to use DWI to be helpful in the characterization of focal liver lesions, especially if the lesions show non classic appearance of contrast enhancement in Triphasic CT study and in patients with renal insufficiency with inability to use contrast enhancement. Recommendations: in our opinion, DWI is a useful adjunct to routine liver imaging (i.e. used as an additional sequence to the standard protocol study and not as a unique imaging series); it is fast, requires no intravenous contrast and is non-invasive. The radiologist has to be aware of the potential pitfalls and limitations of the technique. In patients who cannot receive gadolinium-based contrast agents, DW MR imaging has the potential to be a reasonable alternative technique to contrast-enhanced imaging. We suggest the following strategy for evaluating DWI features of FLLs. We believe that most of the FLLs can be practically classified as benign or malignant by using this scheme.

Importance of Distending Stomach With Fluid for Ultrasound Detection of Focal Lesion in the Elongated Left Lobe of the Liver.

The purpose of this study was to evaluate distending the stomach with water for ultrasound detection of focal lesions in the elongated left lobe of the liver. A total of 13,277 patients undergoing liver ultrasound were evaluated for the presence of an elongated left lobe of the liver and a focal lesion. Patients with an elongated left lobe of the liver had their stomach distended with oral water for further evaluation of a focal lesion. A portion of the patients had computed tomography (CT) examinations, which were compared with the ultrasound studies. A total of 643 patients were found with elongated left lobe of the liver by ultrasound; of them, 451 underwent CT, 259 out of the 451 patients meeting the inclusion criteria underwent second ultrasound and final analysis, and 16 of these 259 patients had focal lesion in the elongated left lobe of the liver on CT study. The sonographic visualization of the liver and spleen at the same scan view before and after distending the stomach were 7% (7 of 100) and 100% (100 of 100), respectively (P < .001). The sonographic detection of the lesions before and after distending the stomach were zero and 87.5%, respectively (P < .001). Distending the stomach with water can greatly increase ultrasound detection of focal lesions in the elongated left lobe of the liver.

Assessment of Total Lesion Glycolysis by 18F FDG PET/CT Significantly Improves Prognostic Value of GEP and ISS in Myeloma.

Purpose: Fluorine-18 fluorodeoxyglucose positron emission tomography with CT attenuation correction (18F-FDG PET/CT) is useful in the detection and enumeration of focal lesions and in semiquantitative characterization of metabolic activity (glycolytic phenotype) by calculation of glucose uptake. Total lesion glycolysis (TLG) and metabolic tumor volume (MTV) have the potential to improve the value of this approach and enhance the prognostic value of disease burden measures. This study aims to determine whether TLG and MTV are associated with progression-free survival (PFS) and overall survival (OS), and whether they improve risk assessments such as International Staging System (ISS) stage and GEP70 risk.Experimental Design: 192 patients underwent whole body PET/CT in the Total Therapy 3A (TT3A) trial and were evaluated using three-dimensional region-of-interest analysis with TLG, MTV, and standard measurement parameters derived for all focal lesions with peak SUV above the background red marrow signal.Results: In multivariate analysis, baseline TLG > 620 g and MTV > 210 cm3 remained a significant factor of poor PFS and OS after adjusting for baseline myeloma variables. Combined with the GEP70 risk score, TLG > 205 g identifies a high-risk-behaving subgroup with poor expected survival. In addition, TLG > 205 g accurately divides ISS stage II patients into two subgroups with similar outcomes to ISS stage I and ISS stage III, respectively.Conclusions: TLG and MTV have significant survival implications at baseline and offer a more precise quantitation of the glycolytic phenotype of active disease. These measures can be assessed more readily than before using FDA-approved software and should be standardized and incorporated into clinical trials moving forward. Clin Cancer Res; 23(8); 1981-7. ©2016 AACR.