Radiology

BackgroundProstate-specific membrane antigen (PSMA) imaging has been suggested as highly sensitive modality for detection of metastases in patients with biochemically recurrent or advanced prostate cancer (PCa). PSMA expression is associated with grade and stage and has a relationship with androgen receptor signaling. The aim of this study was to evaluate the prognostic utility of radiographic PSMA expression in men with metastatic castration-resistant prostate cancer (mCRPC).MethodsPatients with mCRPC and available baseline PSMA imaging were studied. Images by planar/single-photon emission computed tomography (SPECT) or positron emission tomography (PET)/CT were reviewed. Planar/SPECT images were scored semi-quantitatively and PET/CT scored quantitatively with comparison of tumor uptake to liver uptake on a scale of 0–4 in order to determine an imaging score (IS). The IS (high: 2–4 versus low: 0–1), subsequent receipt of life-prolonging systemic therapies (taxane chemotherapy, pote...

Purpose-The goal of this study is to describe CT findings in patients with clinically proven temporal bone osteoradionecrosis (TB-ORN). Methods and materials-CT scans of twenty patients were retrospectively evaluated for bony and soft tissue abnormalities. Clinical severity was graded based on level of therapy administered: mild (observation), moderate (antibiotics/hyperbaric oxygen), or severe (surgery). Results-Radiation dose to the primary tumor ranged from 30 to 75.6 Gy. Time to onset of ORN from completion of radiation therapy was 2 to 22 years (median=7yrs). Clinical findings: Exposed bone=20/20, otorrhea=17/20, hearing loss=11/20, otalgia=10/20, facial nerve paralysis=2/20, gait imbalance=2/20. CT findings: EAC erosions=18/20, mastoid effusion=18/20, mastoid bony coalescence=5/20, enhancing soft tissue=6/20, soft tissue gas=6/20, temporomandibular joint/condylar erosion=3/20. 3 patients developed an abscess. Conclusion-Mastoid effusion and EAC erosions are commonly seen with TB-ORN. Clinically moderate or severe cases of TB-ORN are more likely to demonstrate enhancing soft tissue (p=0.002), soft tissue gas (p=0.002), and temporomandibular joint involvement (p=0.07).

The significant improvement of patient outcomes from minimally invasive lung surgery has led to the development of advanced lung nodule localization techniques to help manage patients with small suspicious lung nodules or to help resect patients with small pulmonary metastases. However, there are no clear computed tomography (CT) criteria to guide the use of advanced localization techniques for this group of patients. We conducted a retrospective chart review of patients who had undergone initial wedge resection of single or multiple lung nodules. We collected demographics, surgical information and surgical outcomes as well as CT scan features. Multiple logistic regression was performed to determine which factors were most predictive of the need for advanced localization techniques. A total of 45 patients (73%) were resected by direct identification alone while 17 patients (27%) required advanced localization techniques. Of those requiring advanced localization, 11 patients had cone...

Background: Psoriasis is a chronic inflammatory disorder with defective proliferation and differentiation of keratinocytes. It is associated with metabolic syndrome i.e. dyslipidemia, hypertension, obesity, cardiovascular diseases and insulin resistance. The high incidence of cardiovascular events in psoriasis is highly associated with abnormal lipid metabolism. This case-control study was done in North Indian medical institute to investigate the levels of serum lipids in psoriasis patients taking in account various parameters like weight, height, body mass index, blood pressure and diabetes. Methods: We assessed the fasting lipid profile in 48 psoriasis patients and 48 healthy, age and sex matched controls. Results: The study found significant elevation (p<0.05) of serum total cholesterol, triglycerides, low density lipoproteins (LDL) and very low density lipoproteins (VLDL) in psoriasis patients compared to controls. The levels of high density lipoproteins (HDL) were also significantly lower (p<0.05) in psoriasis patients. Conclusions: This study suggests that psoriasis is a high risk disorder for cardiovascular mortality and morbidity because of its association with dyslipidemia.

Objective To estimate the intra-observer repeatability of shear wave elastography in the UCL of the elbow, and to compare shear wave velocities between dominant and non-dominant arms. Materials and methods Twenty elbows in ten healthy volunteers were evaluated [five males, five females; mean age, 31.8 ± 10.3 years]. Shear wave velocity was measured on three separate days during the span of 1 week utilizing a linear 18-MHz transducer. Elastograms were obtained until ten ROIs were drawn, not drawing more than two ROIs on any elastogram. Elastograms were considered diagnostic if any portion of the UCL was colored in and free of boundary artifacts. Median velocity and interquartile range were recorded. A result was considered reliable if the IQR/median ratio of the ten measurements was < 0.3. Results IQR/median was < 0.3 in 88% of sessions, although in 28% of sessions fewer than 60% of elastograms were diagnostic. The ICC was 0.05 (95% CI; − 0.18-0.36; poor). Repeatability coefficient (95% limits of agreement) was 1.95 m/s (95% CI; 1.61-2.37 m/s). Mean velocity in dominant arms was 5.14 ± 0.53 m/s and 5.24 ± 0.39 m/s in non-dominant (p = 0.558). Conclusions Mean shear wave velocity was similar between dominant and non-dominant arms. Although repeatability was poor as assessed by ICC, the repeatability coefficient may be a more useful indicator of clinical utility once shear wave velocities in diseased ligaments are explored. Future studies should therefore evaluate velocities in diseased ligaments and develop techniques to improve elastogram quality.

Purpose: A Phase 2 trial of stereotactic radiotherapy and in situ cytotoxic virus therapy in patients with metastatic triple-negative breast cancer (mTNBC) followed by pembrolizumab (STOMP) was designed to evaluate dual approach of enhancing single-agent immune checkpoint blockade with adenovirus-mediated expression of herpes-simplex-virus thymidine-kinase (ADV/HSV-tk) plus valacyclovir gene therapy and stereotactic body radiotherapy (SBRT) in patients with mTNBC. Patients and Methods: In this single-arm, open-label Phase 2 trial, patients with mTNBC were treated with ADV/HSV-tk [5 × 1011 virus particles (vp)] intratumoral injection, followed by SBRT to the injected tumor site, then pembrolizumab (200 mg, every 3 weeks). The primary endpoint was clinical benefit rate [CBR; complete response (CR), partial response (PR), or stable disease (SD) ≥ 24 weeks per RECIST version1.1 at non-irradiated site]. Secondary endpoints included duration on treatment (DoT), overall survival (OS), and ...

The solitary pulmonary nodule remains a common clinical problem. The essential question is whether the lesion is malignant or not. This discussion presents the clinical practice and looks at the problem. Design: Didactic. Setting: Academic tertiary-care hospital. Patients: Prospective thoracic database. Interventions: Minimally invasive technique. Results: The workup and treatment of the solitary pulmonary nodule is presented with particular emphasis on the role of minimally invasive techniques. A small single-institution series is referenced. Conclusions: The approach is safe and highly effective in diagnosing and often in treating solitary pulmonary nodules.

New intravital optical imaging technologies have revolutionized our understanding of mammalian biology and continue to evolve rapidly. However, there are only a limited number of imaging probes available to date. In this study, we investigated in mouse models of glioblastoma whether a fluorescent small molecule inhibitor of the DNA repair enzyme PARP1, PARPi-FL, can be used as an imaging agent to detect glioblastomas in vivo. We demonstrated that PARPi-FL has appropriate biophysical properties, low toxicity at concentrations used for imaging, high stability in vivo, and accumulates selectively in glioblastomas due to high PARP1 expression. Importantly, subcutaneous and orthotopic glioblastoma xenografts were imaged with high contrast clearly defining tumor tissue from normal surrounding tissue. This research represents a step toward exploring and developing PARPi-FL as an optical intraoperative imaging agent for PARP1 in the clinic.

Accurate visualization and quantification of β-cell mass is critical for the improved understanding, diagnosis, and treatment of both type 1 diabetes (T1D) and insulinoma. Here, we describe the synthesis of a bimodal imaging probe (PET/fluorescence) for imaging GLP-1R expression in the pancreas and in pancreatic islet cell tumors. The conjugation of a bimodal imaging tag containing a near-infrared fluorescent dye, and the copper chelator sarcophagine to the GLP-1R targeting peptide exendin-4 provided the basis for the bimodal imaging probe. Conjugation was performed via a novel sequential one-pot synthetic procedure including 64 Cu radiolabeling and copper-catalyzed click-conjugation. The bimodal imaging agent 64 Cu-E4-Fl was synthesized in good radiochemical yield and specific activity (RCY = 36%, specific activity: 141 μCi/μg, >98% radiochemical purity). The agent showed good performance in vivo and ex vivo, visualizing small xenografts (<2 mm) with PET and pancreatic β-cell mass by phosphor autoradiography. Using the fluorescent properties of the probe, we were able to detect individual pancreatic islets, confirming specific binding to GLP-1R and surpassing the sensitivity of the radioactive label. The use of bimodal PET/fluorescent imaging probes is promising for preoperative imaging and fluorescence-assisted analysis of patient tissues. We believe that our procedure could become relevant as a protocol for the development of bimodal imaging agents.

To compare the diagnostic performance of diffusionweighted (DW) magnetic resonance (MR) imaging with that of contrast material-enhanced (CE) MR imaging and to assess the performance of these examinations combined for the characterization of renal lesions, with MR follow-up and histopathologic analysis as the reference standards.

Objective: The full diagnostic value of diffusion-weighted (DW) MRI in the evaluation of liver metastases remains uncertain. The aim of the present study was to assess the diagnostic accuracy of DW-MRI and contrast-enhanced MRI (CE-MRI) using extracellular gadolinium chelates, with the reference standard established by consensus interpretation of confirmatory imaging and histopathologic data. Methods: MR examinations of 51 patients with extrahepatic malignancies were retrospectively reviewed by two independent observers who assessed DW-MRI and CE-MRI for detection of liver metastases. Results: By reference standard, 93 liver lesions (49 metastases and 44 benign lesions) were identified in 27 patients, 11 patients had no liver lesions, and 13 patients had innumerable metastatic and/or benign lesions. There was no difference in diagnostic performance between the two methods for either observer for the diagnosis of metastatic lesions per patient. For perlesion analysis, sensitivity of DW-MRI was equivalent to CE-MRI for observer 1 (67.3% vs. 63.3%, p= 0.67), but lower for observer 2 (65.3% vs. 83.7%, p=0.007). By pooling data from both observers, the sensitivity of DW-MRI was 66.3% (65/98) and 73.5% (72/98) for CE-MRI, with no significant difference (p=0.171). Conclusion: DW-MRI is a reasonable alternative to CE-MRI for the detection of liver metastases.

Purpose: To assess the diagnostic accuracy of image subtraction compared with nonsubtracted images obtained with contrast-enhanced T1-weighted imaging (CE T1WI) for the diagnosis of hepatocellular carcinoma (HCC) necrosis after transarterial chemoembolization (TACE), using liver explant as the reference standard.

Portal venous hypertension (PVH) is important in several clinical situations, particularly in patients with cirrhosis who are at risk of potentially life-threatening variceal haemorrhage. Portal venous pressures can be measure directly but only by invasive techniques that are often not practical for serial monitoring or evaluating treatment response. Over the last four decades alternative indirect non-invasive markers have been investigated including portal venous flow, splenic size, and portal vein diameter but none of these have proven to be reliable indicators of PVH. Currently the most widely used method remains an invasive one -the use of hepatic vein wedge pressure measurements [1]. This technique is safer than direct splenic puncture methods but remains relatively impractical for many patients.

Cirrhosis is an important and growing public health problem, affecting millions of Americans and many more people internationally. A pathological hallmark of the progression to cirrhosis is the development of liver fibrosis, so that monitoring the appearance and progression of liver fibrosis can be used to guide therapy. We here report a method to use magnetization-tagged magnetic resonance imaging (MRI) to measure the cardiac-induced motion and deformation in the liver, as a means for noninvasively assessing liver stiffness, which is related to fibrosis. The initial results show statistically significant differences between healthy and cirrhotic subjects in the direct comparisons of the maximum displacement (mm), and the maximum (P1) and minimum (P2) 2D strains, through the cardiac cycle (3.514 ± 0.793, 2.184 ± 0.611; 0.116 ± 0.043, 0.048 ± 0.011; −0.094 ± 0.020, −0.041 ± 0.015; healthy, cirrhosis, respectively; p < 0.005 for all). There are also significant differences in the displacement-normalized P1 and P2 strains (mm−1) (0.030 ± 0.008, 0.017 ± 0.007; −0.024 ± 0.006, −0.013 ± 0.004; healthy, cirrhosis, respectively; p < 0.005 for all). Therefore, this noninvasive imaging-based method is a promising means to assess liver stiffness using clinically available imaging tools.

Category: 36. CT Coronary Angiography Session-Poster Board Number: 1025-Background: Novel cardiac computed tomography angiography (CCTA) algorithms emphasize radiation dose reduction while maintaining diagnostic image quality. This study evaluated image quality (IQ) and diagnostic concordance using a prospectively ECG-triggered high-pitch spiral acquisition (FLASH spiral) dual source CCTA acquisition compared to retrospective ECG gating (RG) for coronary artery disease evaluation.

This study evaluates the performance of diffusion-weighted magnetic resonance imaging (DWI) for the detection of hepatocellular carcinoma (HCC) in pre–liver transplantation patients, compared and combined with contrast-enhanced T1-weighted imaging (CET1WI), using liver explant as the standard of reference. We included 52 patients with cirrhosis (40 men, 12 women; mean age, 56 years) who underwent DWI and CET1WI within 90 days of liver transplantation. Magnetic resonance images were analyzed for HCC detection in three separate sessions by two independent observers: DWI images (DW-set), CET1WI (CE-set), and all images together (All-set). Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), per-patient accuracy, and per-lesion PPV were calculated for each image set. A total of 72 HCCs were present in 33 patients at explant (mean size, 1.5 cm [range, 0.3-6.2 cm]). Per-patient sensitivity and NPV of CE-set were significantly higher than those of DW-set when using pooled data between observers (P = 0.02 and 0.03, respectively), whereas specificity, PPV, and accuracy were equivalent. Per-lesion sensitivity was significantly higher for CE-set versus DW-set (59.0% versus 43.8%; P = 0.008, pooled data from two observers). When stratified by lesion size, the difference was significant only for lesions with a size between 1 and 2 cm (42.0% for DW-set versus 74.0% for CE-set; P = 0.001). The addition of DWI to CET1WI improved sensitivity for the more experienced observer. Conclusion: DWI is outperformed by CET1WI for detection of HCC, but represents a reasonable alternative to CET1WI for detection of HCC with a size above 2 cm. The addition of DWI to CET1WI slightly increases the detection rate. (HEPATOLOGY 2012;56:140–148)

Functional magnetic resonance imaging (fMRI) techniques enable noninvasive assessment of renal function. Diffusion-weighted imaging, diffusion tensor imaging, blood oxygen level–dependent MRI, magnetic resonance elastography, and arterial spin labeling are some of the emerging techniques that have potential to investigate renal function without the use of exogenous gadolinium contrast. This article discusses the principles of these techniques, as well as their possible applications and limitations. This will introduce the readers to these novel imaging tools, which appear to have promising futures.

A 29-year-old man was ejected from a car in a high-speed motor-vehicle crash without loss of consciousness. Upon arrival at Harborview Medical Center (HMC) he complained of neck and lower abdominal pain. Per HMC trauma protocol, he underwent a standard radiograph trauma series (anteroposterior chest radiograph, lateral view of the cervical spine, and anteroposterior view of the pelvis), which showed multiple fractures of the cervical spine. Physical examination demonstrated gross hematuria. The patient was stable and was sent for computed tomography (CT) angiography of the chest and neck followed by a venous phase scan of the abdomen and pelvis. Cervical CT confirmed multiple unstable factures of the cervical spine, cord compression, and a left vertebral artery stretch injury. A small amount of low-density fluid in the pelvis was the only abnormality noted at abdominal and pelvic CT . This prompted further investigation with CT cystography, which showed a superior bladder wall tear with intraperitoneal rupture and contrast/urine extravasation throughout the peritoneal cavity . There was no evidence of extraperitoneal bladder rupture. The patient underwent a cystorrhaphy with a favorable outcome.