Detection Of Small Lesions Research Articles

Small lesion depiction and quantification accuracy of oncological 18F-FDG PET/CT with small voxel and Bayesian penalized likelihood reconstruction

BackgroundTo investigate the influence of small voxel Bayesian penalized likelihood (SVB) reconstruction on small lesion detection compared to ordered subset expectation maximization (OSEM) reconstruction using a clinical trials network (CTN) chest phantom and the patients with 18F-FDG-avid small lung tumors, and determine the optimal penalty factor for the lesion depiction and quantification.MethodsThe CTN phantom was filled with 18F solution with a sphere-to-background ratio of 3.81:1. Twenty-four patients with 18F-FDG-avid lung lesions (diameter < 2 cm) were enrolled. Six groups of PET images were reconstructed: routine voxel OSEM (RVOSEM), small voxel OSEM (SVOSEM), and SVB reconstructions with four penalty factors: 0.6, 0.8, 0.9, and 1.0 (SVB0.6, SVB0.8, SVB0.9, and SVB1.0). The routine and small voxel sizes are 4 × 4 × 4 and 2 × 2 × 2 mm3. The recovery coefficient (RC) was calculated by dividing the measured activity by the injected activity of the hot spheres in the phantom study. The SUVmax, target-to-liver ratio (TLR), contrast-to-noise ratio (CNR), the volume of the lesions, and the image noise of the liver were measured and calculated in the patient study. Visual image quality of the patient image was scored by two radiologists using a 5-point scale.ResultsIn the phantom study, SVB0.6, SVB0.8, and SVB0.9 achieved higher RCs than SVOSEM. The RC was higher in SVOSEM than RVOSEM and SVB1.0. In the patient study, the SUVmax, TLR, and visual image quality scores of SVB0.6 to SVB0.9 were higher than those of RVOSEM, while the image noise of SVB0.8 to SVB1.0 was equivalent to or lower than that of RVOSEM. All SVB groups had higher CNRs than RVOSEM, but there was no difference between RVOSEM and SVOSEM. The lesion volumes derived from SVB0.6 to SVB0.9 were accurate, but over-estimated by RVOSEM, SVOSEM, and SVB1.0, using the CT measurement as the standard reference.ConclusionsThe SVB reconstruction improved lesion contrast, TLR, CNR, and volumetric quantification accuracy for small lesions compared to RVOSEM reconstruction without image noise degradation or the need of longer emission time. A penalty factor of 0.8–0.9 was optimal for SVB reconstruction for the small tumor detection with 18F-FDG PET/CT.

Accuracy of MRI, CT, and Ultrasound imaging on thickness and depth of oral primary carcinomas invasion: a systematic review.

The aim of this study was to perform a systematic review to assess the sensitivity, specificity, and accuracy of magnetic resonance imaging (MRI), computed tomography (CT), and intraoral ultrasound (US) to determine the depth of invasion (DOI) and/or tumor thickness (TT) in oral cavity cancers, with histopathological evaluation as the gold standard. Articles whose primary objective was to evaluate the accuracy (sensitivity and specificity) of MRI, CT, and US imaging to assess DOI and/or TT were searched in six major electronic databases, in addition to three grey literature databases. The methodological quality of the selected studies was evaluated by using the Quality Assessment Tool for Diagnostic Accuracy Studies-2. Twelve studies met the inclusion criteria and underwent qualitative analysis: six studies on MRI, three on US, and one on CT. The accuracy values for MRI ranged from 67 to 83%, with sensitivity values above 80% and specificity above 75%. For US, mean values of sensitivity ranged from 91 to 93%. For CT, accuracy was 75%. For the application of US, CT, MRI, good accuracy was reported in DOI and/or TT, as evaluated in the preoperative period. US offered advantages for detection of small lesions.

Restoration of Tc-99m methyl diphosphonate bone scan image using Richardson-Lucy algorithm.

In this study, the optimal input parameters point spread function (PSF) and the number of iterations of the Richardson-Lucy algorithm were experimentally determined to restore Tc-99 m methyl diphosphonate (MDP) whole-body bone scan images. The experiment was performed on 60 anonymized Tc-99 m MDP whole-body bone scan images. Ten images were used for estimating the optimum value of PSF and the number of iterations to restore scintigraphic images. The remaining 50 images were used for validation of estimated parameters. The image quality of observed and restored images was assessed objectively using blind/referenceless image spatial quality evaluator (BRISQUE), mean brightness (MB), discrete entropy (DE), and edge-based contrast measure (EBCM) image quality metrics. Image quality was subjectively assessed by two nuclear medicine physicians (NMPs) by comparing the restored image quality with observed image quality and assigning a score to each image on the scale of 0-5. Based on BRISQUE, MB, DE, and EBCM scores, the restored images were significantly sharper, less bright, had more detailed information, and had less contrast around edges compared to the input images. The restored images had improved resolution based on visual assessment as well; NMPs assigned an average image quality score of 4.00 to restored images. Maximum resolution enhancement was noticed at PSF (size: 11 pixels, sigma: 1.75 pixels) and the number of iterations = 10. With the increase in the number of iterations, noise also gets amplified along with resolution enhancement and affects the detectability of small lesions; in the case of relatively low noisy input images, the number of iterations = 5 gave better results. Tc-99 m MDP bone scan images were restored to improve image quality using the Richardson-Lucy algorithm. The optimum value of the PSF parameter was found to be of size = 11 pixels and sigma = 1.75 pixels.

Effect of Different Modalities of Purgative Preparation on the Diagnostic Yield of Small Bowel Capsule for the Exploration of Suspected Small Bowel Bleeding: A Multicenter Randomized Controlled Trial.

The aim of our study was to compare clear liquid diet with 2 different polyethylene glycol (PEG)-based bowel preparation methods regarding diagnostic yield of small bowel capsule endoscopy (SBCE) in patients with suspected small bowel bleeding (SBB). In this prospective multicenter randomized controlled trial, consecutive patients undergoing SBCE for suspected SBB between September 2010 and February 2016 were considered. Patients were randomly assigned to standard regimen, that is, clear fluids only (prep 1), standard regimen plus 500 mL PEG after SBCE ingestion (prep 2), or standard regimen plus 2 L PEG plus 500 mL PEG after SBCE ingestion (prep 3). The primary outcome was the detection of at least one clinically significant lesion in the small bowel. The quality of small bowel cleansing was assessed. A questionnaire on the clinical tolerance was filled by the patients. We analyzed 834 patients. No significant difference was observed for detection of P1 or P2 small bowel lesions between prep1 group (40.5%), prep 2 group (40.2%), and prep 3 group (38.5%). Small bowel cleansing was improved in prep 2 and 3 groups compared with that in prep 1 group. Compliance to the preparation and tolerance was better in prep 2 group than in prep 3 group. Small bowel purgative before SBCE allowed better quality of cleansing. However, it did not improve diagnostic yield of SBCE for suspected SBB.

New standards for phantom image quality and SUV harmonization range for multicenter oncology PET studies.

Not only visual interpretation for lesion detection, staging, and characterization, but also quantitative treatment response assessment are key roles for 18F-FDG PET in oncology. In multicenter oncology PET studies, image quality standardization and SUV harmonization are essential to obtain reliable study outcomes. Standards for image quality and SUV harmonization range should be regularly updated according to progress in scanner performance. Accordingly, the first aim of this study was to propose new image quality reference levels to ensure small lesion detectability. The second aim was to propose a new SUV harmonization range and an image noise criterion to minimize the inter-scanner and intra-scanner SUV variabilities. We collected a total of 37 patterns of images from 23 recent PET/CT scanner models using the NEMA NU2 image quality phantom. PET images with various acquisition durations of 30-300s and 1800s were analyzed visually and quantitatively to derive visual detectability scores of the 10-mm-diameter hot sphere, noise-equivalent count (NECphantom), 10-mm sphere contrast (QH,10mm), background variability (N10mm), contrast-to-noise ratio (QH,10mm/N10mm), image noise level (CVBG), and SUVmax and SUVpeak for hot spheres (10-37mm diameters). We calculated a reference level for each image quality metric, so that the 10-mm sphere can be visually detected. The SUV harmonization range and the image noise criterion were proposed with consideration of overshoot due to point-spread function (PSF) reconstruction. We proposed image quality reference levels as follows: QH,10mm/N10mm ≥ 2.5 and CVBG ≤ 14.1%. The 10th-90th percentiles in the SUV distributions were defined as the new SUV harmonization range. CVBG ≤ 10% was proposed as the image noise criterion, because the intra-scanner SUV variability significantly depended on CVBG. We proposed new image quality reference levels to ensure small lesion detectability. A new SUV harmonization range (in which PSF reconstruction is applicable) and the image noise criterion were also proposed for minimizing the SUV variabilities. Our proposed new standards will facilitate image quality standardization and SUV harmonization of multicenter oncology PET studies. The reliability of multicenter oncology PET studies will be improved by satisfying the new standards.

CD47-targeted optical molecular imaging and near-infrared photoimmunotherapy in the detection and treatment of bladder cancer

Transurethral resection of bladder tumor (TURBT) followed by intravesical therapy remains the most effective strategy for the management of non-muscle-invasive bladder cancer worldwide. TURBT has two purposes: to remove all visible tumors and to obtain tumor specimens for histopathological analysis. However, the detection of flat and small malignant lesions under white-light cystoscopy is extremely challenging, and residual lesions are still the main reason for the high recurrence rate of bladder cancer. We hypothesized that visual enhancement of malignant lesions using targeted optical molecular imaging could potentially highlight residual tumors in the bladder during surgery, and near-infrared photoimmunotherapy (NIR-PIT) could kill exfoliated cancer cells and residual tumors. A mouse model of complete or partial bladder tumor resection was established under the guidance of optical molecular imaging mediated by indocyanine green and anti-CD47-Alexa Fluor 790, respectively. Once the tumor recurred, mouse model received repeated CD47-targeted NIR-PIT. After complete resection, there was no tumor recurrence. Furthermore, the growth rate of recurrent tumor decreased significantly after repeated NIR-PIT. Therefore, CD47-targeted optical molecular imaging can potentially assist urologists to detect and remove all tumors, and repeated NIR-PIT shows the potential to reduce tumor recurrence rates and inhibit the growth of recurrent tumor.

Image-Enhanced Capsule Endoscopy Improves the Identification of Small Intestinal Lesions.

Image-enhanced endoscopy is useful for diagnosing and identifying lesions in the gastrointestinal tract. Recently, image-enhanced endoscopy has become a breakthrough technology that has attracted significant attention. This image enhancing technology is available for capsule endoscopy, which is an effective tool for small intestinal lesions and has been applied in flexible spectral color enhancement technology and in contrast capsule like narrow-band imaging. In this field, most researchers focus on improving the visibility and detection of small intestinal lesions. This review summarizes previous studies on image-enhanced capsule endoscopy and aims to evaluate the efficacy of this technology.

Role of MRI in Detecting and Characterizing Small Hepatic Focal Lesions

Abstract Background Despite the recent advances in liver imaging, the detection and characterization of small hepatic focal lesions is still a real challenge. Particularly in cancer patients where the characterization of a small HFL as thus the precise tumor staging is critical for optimal treatment planning. Aim of the Work To explore the effectiveness, and hence the clinical utility, of MRI detection and characterization of small focal hepatic lesions either only discovered on MRI or as a further work up of CT/US-indeterminate lesions. Patients and Methods We reviewed our database for individuals who underwent liver MR imaging between March 2018 and March 2019 for the evaluation of small hepatic lesions that were discovered for the first time or had been previously visualized on routinely performed CT and had been considered indeterminate. Results The present study included 44 patients of which 26 were males (59.1%) and 18 were females (40.9%). The age range of the study group was 19 to 77 years. The mean age for Malignant lesions was 51 years. The right lobe of liver was involved in 23 cases (52.3%), left lobe in 5 cases (11.4%) and both lobes in 16 cases (36.4%). There were 30 (68.18%) benign, 13 (29.54%) malignant lesions and 1 (2.3%) indeterminate, hemangiomas were predominant in benign lesions whereas hepatocellular carcinomas were predominant in malignant lesions. N'TRI could characterize 92% cases. Conclusion The diagnostic process of small hepatic focal lesions, either detection or characterization or both, continues to represent a challenge. Contrast-enhanced MR can accurately detect and characterize majority of small hepatic focal lesions.

Video Capsule Endoscopy In Comparison To Radiological Examination In Detection Of Small Bowel Lesions

Abstract BACKGROUND Small bowel obscured its lesions as secrets which were difficult to diagnose before video capsule endoscopy as a new modality for investigation. Aim of the study Evaluation of video capsule endoscopy in comparison to radiological examination in detection of small bowel lesions. Patients and methods Fifty patients were recruited from Kafrawy Video Capsule Endoscopy Unit of Internal Medicine Department and endoscopy unit of Ain Shams University Hospital. The study included patients with occult or overt GIT bleeding, patients with unexplained microcytic iron deficiency anemia, patients with chronic diarrhea and abdominal pain, with normal upper GI endoscopy and colonoscopy. Exclusion of any patient younger than 18 years old, has intestinal stricture, achalasia, or dysphagia. All patients were studied biochemically with CBC and radiological by CT pelvis and abdomen with IV and oral positive contrast some of them were radiologically examined with CTE or CT mesenteric angiography. All patients were endoscopically examined by OGD, colonoscopy, VCE, and some of them were examined also with enteroscope. Results The study revealed that the detection rate of SB lesions with VCE was 84%. In the current study, (44%) of cases had AVMs, (72.73) % of them were above the age of forty five, and (27.27) % were below the age of forty five. All patients who were investigated with CT mesenteric angiography revealed negative results. In this study (20) % of patients had SB masses and polyps, (70) % of them were at age of forty five or more and only (30) % of them were below the age of forty five. All patients underwent CT pelvis and abdomen with IV and oral positive contrast, and we found that all patients had a negative results regarding the SB lesions. In comparison between CTE and VCE in detection of SB vascular lesions CTE did not detect SB vacular lesions. On the other hand, VCE detected the AVMs in the cases with negative CTE results. In this study one patient (2)% was diagnosed with hookworm infection. All patient underwent for OGD. We found that (20)% of patients had a significant gastric or duodenal lesions (proximal to the papilla) by VCE but missed by upper GI endoscopy. In our study the concomitant of VCE and enteroscope increase the detection of SB vascular lesions than isolated use of VCE only. Conclusion VCE has a high detection rate of SB lesions (84)%. CTE has a low significance in detection of SB vascular lesions and CT mesenteric angiography sensitivity relatively low. AVMs more common with increasing the age. PHE and SB ectopic varicies, were found to be common causes of GIT bleeding in CLD patient. There is a significant rate of missed gastric and duodenal (proximal to the papilla) lesions that the cause of GIT bleeding and unexplained iron deficiency anemia in OGD examination that were detected by VCE.

S2484 Endoscopic Ultrasound With Fine Needle Aspiration for Diagnosis of Pancreatic Tumors in Patients With Benign Magnetic Resonance Imaging: Single Center Case Series

Introduction: Pancreatic cancer is the fourth leading cause of cancer-related death in the United States. Computed tomography (CT) scan and Magnetic resonance imaging (MRI) are used for early detection of small pancreatic lesions and cancer risk stratification. Endoscopic ultrasonography (EUS) with FNA (Fine Needle Aspiration) provides accurate diagnosis of pancreatic tumors. This case series introduces four cases of pancreatic tumors diagnosed using EUS/FNA that have been missed on MRI studies Case Description/Methods: Case 1 64-year-old male was referred for evaluation of pancreatic duct dilation on MRI with no detected mass. EUS revealed 15mm x 15mm mass of pancreas. FNA was performed and pathology was consistent with adenocarcinoma Case 2 55-year-old female was referred for evaluation of pancreatic cystic lesion found on MRI with no worrisome features. EUS revealed 15mm x 15mm pancreatic lesion. FNA was performed and pathology was consistent with pancreatic neuroendocrine tumor. Case 3 82-year-old female was referred for evaluation of pancreatic duct dilation on MRI with no discrete mass identified. EUS revealed 26mm x 27mm pancreatic lesion. FNA was performed and pathology was consistent with invasive adenocarcinoma. Case 4 62-year-old male was referred for evaluation of pancreatic lesion on MRI abdomen with features consistent with lipoma. EUS revealed 15mm x 13mm pancreatic lesion. FNA was performed and pathology was consistent with adenocarcinoma. Discussion: The diagnosis of pancreatic neoplasms relies heavily on identification of lesions on CT and MRI. While the sensitivity of MRI is similar to that of CT, the former is preferred in patients with high pre-test probability of pancreatic neoplasms. Sensitivity of EUS has been shown to be significantly higher in detecting pancreatic tumors when compared to CT, However, studies evaluating EUS to MRI are scarce. This case series presents four patients in whom pancreatic tumors were missed on MRI. Two patients had no radiologic evidence of a tumor, while the other two demonstrated lesions with no malignant features. EUS has the added benefit of tumor sampling and higher sensitivity in detecting pancreatic lesions. This case series highlights the potential limitations in the use of MR imaging in diagnosis of pancreatic cancers. Some evidence suggests that EUS is more sensitive than MRI and CT in detecting pancreatic lesions. However, the cost effectiveness and risks associated with routine EUS in the detection of pancreatic lesions has not been evaluated.Figure 1.: (A): Case 3 EUS with arrow pointing at 26mm x 27mm pancreatic lesion (B): Case 4 EUS with arrow pointing at 15mm x 13mm pancreatic lesion.

State of the art of magnetic resonance imaging ( MRI ) in evaluation of focal hepatic lesions

Background: The recent developments in (MRI) sequences for the upper abdomen comprise unenhanced diffusion-weighted imaging (DWI), and (DCE) MRI. DWI allows improved detection of small (< 10 mm) focal liver lesions and useful as a road map sequence. The aim of this work was to study recent and advanced magnetic resonance imaging (MRI) techniques in the evaluation of focal hepatic lesions. Methods: this study included 40 patients, patients underwent assessment with recent MRI sequences (DWI), DCE MRI, T2-weighted imaging, steady-state free precession (SSFP) imaging and T1 in-phase/out-phase imaging. Results: Half of the studied patients were females. Age ranged from 30 to 67 years with mean 48.825 years. Forty percent of patients had right-side lesion while 22.5% had left side lesion. On HPE of the studied patients, 52.5% had malignant growth while the remaining 47.5% had benign lesions. About 23% had HCC. One fifth had hemorrhagic cyst and the same percentage had metastatic lesion. Adenoma was present in 7.5%, There is statistically significant relation between nature of foci and ADC value (significantly higher in benign lesions). ROC curve of ADC in diagnosis of benign nature of focal hepatic masses among the studied patients; area under curve 0.945, (p < 0.05). Conclusion: diffusion-weighted MRI sequence with quantitative ADC measurements should be used as an additional sequence to supplement conventional MRI protocol studies for proper detection (using low b values) and characterization (using high b values) of focal liver lesions

Automatic Kidney Lesion Detection for CT Images Using Morphological CNN

The CT scan is the best tool for diagnosing and finding injuries in the kidney. It can provide precise information about the location and size of lesions in many medical applications. Manual and traditional medical tests work and time-consuming. The automatic detection of injuries in CT is now an integral task for clinical diagnosis. To develop and improve the efficiency of medical testing computer-aided diagnosis (CAD) is needed. However, the existing low accuracy and incomplete detection algorithm remain a tremendous challenge. The proposed lesion sensor is based on morphological cascaded convolutional neural networks using a multi-intersection threshold (IOU) (CNNs). To increase network stability and morphology co-detection layers and amended pyramid networks in the faster RCNN and combine four IOU threshing thresholds with cascade RCNNs and for better detection of small lesions (1-5 mm). In addition, the experiments have been conducted on CT deep-lesion kidney pictures published by photos and communication systems of hospitals (PACSs

Detecting lumbar lesions in 99m Tc-MDP SPECT by deep learning: Comparison with physicians.

99m Tc-MDP single-photon emission computed tomography (SPECT) is an established tool for diagnosing lumbar stress, a common cause of low back pain (LBP) in pediatric patients. However, detection of small stress lesions is complicated by the low quality of SPECT, leading to significant interreader variability. The study objectives were to develop an approach based on a deep convolutional neural network (CNN) for detecting lumbar lesions in 99m Tc-MDP scans and to compare its performance to that of physicians in a localization receiver operating characteristic (LROC) study. Sixty-five lesion-absent (LA) 99m Tc-MDP studies performed in pediatric patients for evaluating LBP were retrospectively identified. Projections for an artificial focal lesion were acquired separately by imaging a 99m Tc capillary tube at multiple distances from the collimator. An approach was developed to automatically insert lesions into LA scans to obtain realistic lesion-present (LP) 99m Tc-MDP images while ensuring knowledge of the ground truth. A deep CNN was trained using 2.5D views extracted in LP and LA 99m Tc-MDP image sets. During testing, the CNN was applied in a sliding-window fashion to compute a 3D "heatmap" reporting the probability of a lesion being present at each lumbar location. The algorithm was evaluated using cross-validation on a 99m Tc-MDP test dataset which was also studied by five physicians in a LROC study. LP images in the test set were obtained by incorporating lesions at sites selected by a physician based on clinical likelihood of injury in this population. The deep learning (DL) system slightly outperformed human observers, achieving an area under the LROC curve (AUCLROC ) of 0.830 (95% confidence interval [CI]: [0.758, 0.924]) compared with 0.785 (95% CI: [0.738, 0.830]) for physicians. The AUCLROC for the DL system was higher than that of two readers (difference in AUCLROC [ΔAUCLROC ]=0.049 and 0.053) who participated to the study and slightly lower than that of two other readers (ΔAUCLROC =-0.006 and -0.012). Another reader outperformed DL by a more substantial margin (ΔAUCLROC =-0.053). The DL system provides comparable or superior performance than physicians in localizing small 99m Tc-MDP positive lumbar lesions.

DEEPMIR: a deep neural network for differential detection of cerebral microbleeds and iron deposits in MRI

Lobar cerebral microbleeds (CMBs) and localized non-hemorrhage iron deposits in the basal ganglia have been associated with brain aging, vascular disease and neurodegenerative disorders. Particularly, CMBs are small lesions and require multiple neuroimaging modalities for accurate detection. Quantitative susceptibility mapping (QSM) derived from in vivo magnetic resonance imaging (MRI) is necessary to differentiate between iron content and mineralization. We set out to develop a deep learning-based segmentation method suitable for segmenting both CMBs and iron deposits. We included a convenience sample of 24 participants from the MESA cohort and used T2-weighted images, susceptibility weighted imaging (SWI), and QSM to segment the two types of lesions. We developed a protocol for simultaneous manual annotation of CMBs and non-hemorrhage iron deposits in the basal ganglia. This manual annotation was then used to train a deep convolution neural network (CNN). Specifically, we adapted the U-Net model with a higher number of resolution layers to be able to detect small lesions such as CMBs from standard resolution MRI. We tested different combinations of the three modalities to determine the most informative data sources for the detection tasks. In the detection of CMBs using single class and multiclass models, we achieved an average sensitivity and precision of between 0.84–0.88 and 0.40–0.59, respectively. The same framework detected non-hemorrhage iron deposits with an average sensitivity and precision of about 0.75–0.81 and 0.62–0.75, respectively. Our results showed that deep learning could automate the detection of small vessel disease lesions and including multimodal MR data (particularly QSM) can improve the detection of CMB and non-hemorrhage iron deposits with sensitivity and precision that is compatible with use in large-scale research studies.

64Cu-PSMA-BCH: a new radiotracer for delayed PET imaging of prostate cancer.

Develop a 64Cu labeled radiopharmaceutical targeting prostate specific membrane antigen (PSMA) and investigate its application for prostate cancer imaging. 64Cu-PSMA-BCH was prepared and investigated for stability, PSMA specificity, and micro-PET imaging. With the approval of Ethics Committee of Beijing Cancer Hospital (No. 2017KT97), PET/CT imaging in 4 patients with suspected prostate cancer was performed and the radiation dosimetry was estimated. Then, PSMA PET-ultrasound image-guided biopsies were performed on 3 patients and the fine needle aspirates were further performed for autoradiography and immunohistochemistry analysis. 64Cu-PSMA-BCH was prepared with high radiochemical yield and stability. In vivo study showed higher uptake in PSMA ( +) 22Rv1 cells than PSMA ( -) PC-3 cells (5.59 ± 0.36 and 1.97 ± 0.22 IA%/106 cells at 1h). It accumulated in 22Rv1 tumor with increasing radioactivity uptake and T/N ratios from 1 to 24h post-injection. In patients with suspected prostate cancer, SUVmax and T/N ratios increased within 24h post-injection. Compared with image at 1h post-injection, more tumor lesions were detected at 6h and 24h post-injection. The human organ radiation dosimetry showed gallbladder wall was most critical, liver and kidneys were followed, and the whole-body effective dose was 0.0292mSv/MBq. Two fine needle aspirates obtained by PET-ultrasound-guided targeted biopsy showed high radioactive signal by autoradiography, with 100% PSMA expression in cytoplasm and 30% expression in nucleus. 64Cu-PSMA-BCH was PSMA specific and showed high stability in vivo with lower uptake in liver than 64Cu-PSMA-617. Biodistribution in mice and PCa patients showed similar profile compared with other PSMA ligands and it was safe with moderate effective dosimetry. The increased tumor uptake and T/N ratios by delayed imaging may facilitate the detection of small lesions and guiding targeted biopsies.

Deep learning-based classification of blue light cystoscopy imaging during transurethral resection of bladder tumors

Bladder cancer is one of the top 10 frequently occurring cancers and leads to most cancer deaths worldwide. Recently, blue light (BL) cystoscopy-based photodynamic diagnosis was introduced as a unique technology to enhance the detection of bladder cancer, particularly for the detection of flat and small lesions. Here, we aim to demonstrate a BL image-based artificial intelligence (AI) diagnostic platform using 216 BL images, that were acquired in four different urological departments and pathologically identified with respect to cancer malignancy, invasiveness, and grading. Thereafter, four pre-trained convolution neural networks were utilized to predict image malignancy, invasiveness, and grading. The results indicated that the classification sensitivity and specificity of malignant lesions are 95.77% and 87.84%, while the mean sensitivity and mean specificity of tumor invasiveness are 88% and 96.56%, respectively. This small multicenter clinical study clearly shows the potential of AI based classification of BL images allowing for better treatment decisions and potentially higher detection rates.

Hopes and Hypes for Artificial Intelligence in Colorectal Cancer Screening

Hopes and Hypes for Artificial Intelligence in Colorectal Cancer Screening

5-ALA-Induced Fluorescent Cytology in the Diagnosis of Bladder Cancer—a Preliminary Report

5-Aminolevulinic acid (ALA)-induced fluorescence cystoscopy has established itself in the detection of flat and/or small lesions. This is explained by the simple fact that there is increased uptake of ALA, altered activity of certain enzymes, and altered intracellular redistribution and storage of protoporphyrin IX (PPIX) in the malignant cells. Intracellular PPIX allows red fluorescence detection. In this preliminary study, the efficacy of 5-ALA-induced fluorescent urine cytology was compared with conventional cytology in the diagnosis of bladder tumours. In this prospective study, patients ≥18years ofage admitted to the department of urology with non-malignant conditions formed the controls and patients ≥18 years of age with imaging confirmed bladder tumours formed the study group. Freshly voided urine sample was collected from these patients and divided into two samples of 50cc each. One of these samples was sent in for conventional cytology examination, whereas the other sample was sent in for 5-ALA fluorescent photo dynamic diagnosis. Conventional cytology and 5-ALA-induced fluorescent cytology were evaluated by the same pathologist. A total of 100 patients were included in the study of which 75 patients were controls and the remaining 25 were patients with bladder tumours. The sensitivity of conventional cytology and 5-ALA-induced fluorescent cytology was 64% and 100% respectively, whereas the specificity was 96% and 98.67% respectively. The sensitivity of conventional cytology was 61.19% in low-grade cancers as compared to 75% in high-grade cancers, whereas the sensitivity was 100% with 5-ALA-induced fluorescent cytology both in low- as well as high-grade cancers. Our study shows that 5-ALA-induced fluorescent cytology is highly sensitive test to diagnose bladder cancer and shows a significant difference especially in low-grade bladder cancer when compared to conventional cytology.

Image Quality and Detection of Small Focal Liver Lesions in Diffusion-Weighted Imaging: Comparison of Navigator Tracking and Free-Breathing Acquisition.

The aim of this study was to compare intraindividual diffusion-weighted imaging (DWI) of the liver acquired with free breathing (FB) versus navigator triggering (NT) for assessing small focal liver lesions (FLLs) in noncirrhotic patients. Patients with known or suspected multiple FLLs were prospectively included, and spin-echo echo-planar DWI with NT and FB acquisition was performed (b-values, 50 and 800 s/mm2 [b50 and b800]). NT and FB DWI sequences with similar acquisitions times were used. Liver and lesion signal-to-noise ratios were measured at b800. The DWI scans were analyzed independently by 2 readers. Liver edge delineation, presence of stair-step artifacts, vessel sharpness, severity of cardiac motion artifacts, overall image quality, and lesion conspicuity were rated with 5-point Likert scales. Small and large FLLs (ie, <1 cm or ≥1 cm) were rated separately for lesion conspicuity. The FLL detectability was estimated by comparing the number of lesions visible with FB to those visible with NT. Forty-three patients were included in the study. The FB acquisition performed better in terms of severity of cardiac motion artifacts. The NT performed better in terms of liver edge delineation and vessel sharpness. Little difference was found for stair-step artifact, overall image quality, and conspicuity of large FLL, whereas the conspicuity of small FLL was better for NT. For small FLL, both readers found more lesions with NT in 11 cases at b800. For large FLL, this effect was much less pronounced (1 case at b800 reported by 1 of the readers). The mean liver and lesion signal-to-noise ratios were 16.8/41.5 and 19.8/38.4 for NT/FB, respectively. Small FLL detection is better with NT. Large FLL detection by FB and NT is similarly good. We conclude that NT should be used.

Gd-EOB-DTPA dynamic contrast-enhanced magnetic resonance imaging is more effective than enhanced 64-slice CT for the detection of small lesions in patients with hepatocellular carcinoma: Erratum.

Gd-EOB-DTPA dynamic contrast-enhanced magnetic resonance imaging is more effective than enhanced 64-slice CT for the detection of small lesions in patients with hepatocellular carcinoma: Erratum.