Comparison of Ga-PSMA PET MRI with mpMRI in localization and regional staging of prostate cancer.

PURPOSE: To compare diagnostic accuracy in localization and detection of extraprostatic extension (EPE), seminal vesicle invasion (SVI), lymph node involvement (LNI) between PSMA PET MRI and multiparametric MRI (mpMRI) in carcinoma prostate. METHODS: We did a prospective study of consecutive men with biopsy-proven prostate cancer who underwent radical prostatectomy between July'2020 and Dec'2021 at our institution. Patients underwent PSMA PET MRI imaging. MpMRI findings were inferred separately by another radiologist who was blinded to the PSMA PET findings. PIRADS > 2 and any standardized uptake value (SUV) were considered positive. Findings were mapped to a 30-region anatomical grid and compared with pathology. The uro-pathologist also marked the presence of the tumor onto the same anatomical grid. The presence of EPE, SVI, and LVI was noted. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The significance in difference: McNemar test. SUVmax and Gleason score: Kruskal-Wallis test. RESULTS: Seventy-five men (mean age 65) with an average PSA of 21.5 ng/ml were included. The sensitivity of PSMA PET MRI for localization was higher [63.6 vs 41.9] (p < 0.001) while specificity was similar [81.5 vs 83.2] (p 0.103). The former had a higher sensitivity to detect SVI [85.7 vs 57.10] (p = 0.03). No difference in the detection of EPE or LNI was noted. SUVmax > 7 was associated with high-risk disease (Gleason score >/= 7). LIMITATIONS: non-randomized nature, higher risk population. CONCLUSION: Ga-PSMA PET MRI improved the localization of prostate cancer and better detection of SVI. Further studies are required. It can act as a single-stop investigation for the primary staging of prostate cancer.

Asymmetry index in anatomically symmetrized FDG-PET for improved epileptogenic focus detection in pharmacoresistant epilepsy.

OBJECTIVE: Positron emission tomography (PET) imaging has assumed an essential role in the presurgical evaluation of epileptogenic foci in drug-resistant epilepsy by identifying the hypometabolic cerebral cortex. The authors herein designed a pilot study to test a novel technique of PET asymmetry after anatomical symmetrization coregistered to MRI (PASCOM), utilizing interhemispheric metabolic asymmetry on interictal fluorine 18-labeled fluorodeoxyglucose (FDG)-PET to better localize the epileptogenic zone. METHODS: The authors analyzed interictal FDG-PET scans from 23 patients with drug-resistant epilepsy, mean (± SD) age 20.9 ± 13.1 years old, who had an Engel class I postsurgical outcome while followed up for > 12 months. T1-weighted and FLAIR MRI were used to create a patient-specific, structurally symmetrical template. The asymmetry index (AI) image was computed to detect the cerebral region of hypometabolism using different z-score threshold criteria to optimize sensitivity and specificity. The detected regions were compared with the resection cavity on postoperative MRI using predefined anatomical labels. PASCOM was compared with the visual analysis of FDG-PET by a nuclear medicine consultant blinded to other clinical data (VIS) and visual analysis during multidisciplinary team discussion (MDT). The efficacy of each technique was compared based on a performance score (S), sensitivity, specificity, and correct lateralization of epileptogenicity. RESULTS: The mean S was maximum (1.30 ± 1.23) for AI images when thresholded at z > 4 and retaining the cluster of more than 100 voxels containing the peak AI value (Z4C) with 73.03% sensitivity and 96.43% specificity. The mean S was minimum for VIS (0.27 ± 0.31). The mean sensitivity was maximum for MDT (85.04%) and minimum for Z5C (AI images thresholded at z > 5 and clustered; 59.47%), whereas the mean specificity was maximum for Z5C (97.77%) and minimum for VIS (64.60%). Z3C (AI images thresholded at z > 3 and clustered) and Z4C were able to correctly identify the side of epileptogenicity in all the patients. CONCLUSIONS: The PASCOM technique with a Z4C threshold had a maximum performance score with good sensitivity and specificity in localizing and lateralizing the epileptogenic zone. The described technique outperformed the conventional visual analysis of FDG-PET and hence warrants further prospective verification.

Statistical asymmetry analysis of volumetric MRI and FDG PET in temporal lobe epilepsy.

PURPOSE: To analyze statistically derived threshold values of volumetric MRI and 18F fluorodeoxyglucose (FDG) PET asymmetry, independent of normative data, for non-invasive detection/exclusion of temporal lobe epilepsy (TLE). METHODS: We retrospectively analyzed amygdalohippocampal volumetry and temporal FDG PET metabolism in 33 patients (age: 29.27 ±â€¯8.56 years) who underwent surgery following Stereo-EEG implantation and had postsurgical seizure freedom lasting >12 months. The temporal lobe epilepsy group and the extratemporal lobe epilepsy (ETLE) group were compared. Percentage volume loss (PVL) was calculated from manually traced amygdalohippocampal volumetry whereas percentage metabolic loss (PML) was calculated from PET using amygdalohippocampal trace and temporal neocortical Brodmann areas (BA) template. RESULTS: Receiver operating characteristic (ROC) curve analysis identified a cutoff hippocampal PVL of 4.21% as the minimum indicating probable hippocampal involvement in seizure onset, with sensitivity of 88.89% and the specificity of 100% (p < 0.001). Region of interest (ROI)-based PML values in PET imaging showed a significant correlation with the presence of TLE in the TLE group of patients and its absence in the ETLE group of patients. Region of interest curve analysis yielded PML cutoffs of 5.77% and 8.36%, respectively, for the hippocampus and BA 38 (temporopolar neocortex) to detect TLE with the sensitivity of 72.7% and specificity of 77.8%. CONCLUSION: We describe statistical thresholds for asymmetry analysis of hippocampal volumetry and FDG PET to improve detection of TLE. These threshold parameters warrant further validation in prospective studies.

Comparison of whole-body bone scintigraphy with axial skeleton magnetic resonance imaging in the skeletal evaluation of carcinoma prostate.

INTRODUCTION: Whole-body bone scintigraphy (WBBS) is considered to be the standard of care in the initial skeletal evaluation of patients with carcinoma prostate. Magnetic resonance imaging (MRI) is a potential alternative technique for detecting bone metastasis. The objective of this study was to compare the diagnostic performance of WBBS with a single-photon emission computed tomography-computed tomography (SPECT-CT) correlation of the suspicious WBBS lesions to the axial skeleton (AS)-MRI in diagnosing bone metastasis in patients with carcinoma prostate. METHODS: WBBS and AS-MRI were both performed during the initial skeletal evaluation in 35 patients of carcinoma prostate with the prostate-specific antigen (PSA) in the range of 10-50 ng/ml. Suspicious lesions on the WBBS were correlated on SPECT CT. The presence or absence of metastasis was determined by best valuable comparator. The validity parameters of WBBS and AS-MRI were computed and compared. RESULTS: The sensitivity, specificity, positive predictive value, and negative predictive value of WBBS and AS-MRI for detecting patients with bone metastasis were 55.6%, 88.5%, 62.5%, 85.2% and 100.0%, 96.2%, 90.0%, 100%, respectively. The kappa value and the accuracy of WBBS were 0.457 and 80.0%, respectively. The kappa value and accuracy of AS-MRI were 0.928 and 97.1%, respectively. CONCLUSIONS: The diagnostic performance of AS-MRI in detecting patients with bone metastasis due to carcinoma prostate is superior to that of WBBS with SPECT-CT correlation of the suspicious lesions in the PSA range of 10-50 ng/ml.

Significance of elevated Prohibitin 1 levels in Multiple Sclerosis patients lymphocytes towards the assessment of subclinical disease activity and its role in the central nervous system pathology of disease.

Multiple Sclerosis (MS) is an autoimmune-neurodegenerative disorder managed therapeutically by modulating lymphocytes activity which has potential in disease management. Prohibitin 1(PHB) that controls the reactive oxygen species (ROS) and present on the activated lymphocytes have significance in the therapy of MS as esters of fumaric acid that regulates ROS is in phase II/III clinical trials. Thus, we evaluated the expression levels of PHB1 in experimental autoimmune encephalomyelitis (EAE), the animal model of MS and on MS patient's lymphocytes. PHB levels in brain tissue of EAE animals were determined by immunoblotting and on blood lymphocytes from MS relapse, Remission, Optic Neuritis, Neurological controls and Healthy volunteers by FACS using anti-PHB and anti-CD45 antibodies. We observed significant elevation of PHB in EAE brains (91.0 ±â€¯17.59%) vs controls (29.8 ±â€¯12.9%) (p = 0.01) and on lymphocytes of MS patients in acute (73.5 ±â€¯11.20%) or relapsing (69.3 ±â€¯17.33%) phase compared to remission (45.9 ±â€¯8.08%) [p = 0.034 acute vs remission; p = 0.004 relapse vs remission]. Up regulation of PHB in relapsing vs remission MS patients imply the potential use of PHB to clinically evaluate subclinical disease status towards prognosis of an oncoming relapse. Elevated PHB levels in EAE brains signify the role of PHB in regulating ROS and implies PHB's role in oxidative stress.

Percutaneous transhepatic techniques for management of biliary anastomotic strictures in living donor liver transplant recipients.

AIM: To retrospectively analyze the percutaneous transhepatic techniques and their outcome in the management of biliary strictures in living donor liver transplant (LDLT) recipients. MATERIALS AND METHODS: We retrieved the hospital records of 400 LDLT recipients between 2007 and 2015 and identified 45 patients with biliary strictures. Among them, 17 patients (37.8%) (Male: female = 13:4; mean age, 36.1 ± 17.5 years) treated by various percutaneous transhepatic biliary techniques alone or in combination with endoscopic retrograde cholangiopancreatography (ERCP) were included in the study. The technical and clinical success of the percutaneous management was analyzed. RESULTS: Anastomotic strictures associated with leak were found in 12/17 patients (70.6%). Ten out of 12 (83.3%) patients associated with leak had more than one duct-duct anastomoses (range, 2-3). The average duration of onset of stricture in patients with biliary leak was 3.97 ± 2.68 months and in patients with only strictures it was 14.03 ± 13.9 months. In 6 patients, endoscopic-guided plastic stents were placed using rendezvous technique, plastic stent was placed from a percutaneous approach in 1 patient, metallic stents were used in 2 patients, cholangioplasty was performed in 1 patient, N-butyl- 2-cyanoacrylate embolization was done in 1 child with biliary-pleural fistula, internal-external drain was placed in 1 patient, and only external drain was placed in 5 patients. Technical success was achieved in 12/17 (70.6%) and clinical success was achieved in 13/17 (76.5%) of the patients. Posttreatment mean time of follow-up was 19.4 ± 13.7 months. Five patients (29.4%) died (two acute rejections, one metabolic acidosis, and two sepsis). CONCLUSIONS: Percutaneous biliary techniques are effective treatment options with good outcome in LDLT patients with biliary complications.

Seizure outcome following primary motor cortex-sparing resective surgery for perirolandic focal cortical dysplasia.

OBJECTIVES: We present a case series of patients who underwent perirolandic resection for medically refractory focal epilepsy due to focal cortical dysplasia (FCD). Our aim was to specifically evaluate the outcome of a surgical strategy intended for seizure freedom while preserving primary motor cortex function. MATERIALS AND METHODS: Thirteen patients undergoing perirolandic resection for pharmacoresistant focal epilepsy between 2010 and 2015 who demonstrated histological evidence of FCD were selected from a prospectively maintained database. Presurgical evaluation included video EEG telemetry and 3T MRI brain for all patients. Eight patients underwent interictal FDG PET scan. Intracranial EEG monitoring was done for 8 patients - six by conventional subdural grid and depth electrodes and two by Stereo EEG. Additional techniques included extraoperative cortical stimulation mapping, intraoperative electrocorticography (ECoG), intraoperative motor cortex mapping and awake surgery in various combinations. In all cases (lesional and nonlesional), resection was intentionally limited for anatomic preservation of the primary motor cortex. RESULTS: Amongst the thirteen patients with age ranging 14-44 years (mean 26.8 ± 9.2) 62% of them had daily seizures. MRI abnormalities were identified in 8 patients (62%), PET showed concordant findings in 7 patients (88%). When utilized, the mean duration of intracranial EEG recordings was 8.0 ± 7.2 days (range 2-23 days). All patients underwent a primary motor cortex-sparing resection of the suspected epileptogenic cortex. The mean postoperative follow up period was 23 months (range 7.5-62 months). Twelve out of 13 (92%) were seizure free (Engel 1) outcome at the last follow-up assessment; one patient had Engel 2a outcome at 28 months. Six patients (46%) had immediate new focal neurological deficits, however all six patients had recovered completely within three months. CONCLUSION: The surgical strategy of a primary motor cortex-sparing resective surgery for perirolandic FCD is associated with an excellent early seizure-freedom rate and no permanent neurological deficits. Since the ultimate goal of resective epilepsy surgery is seizure freedom with simultaneous functional preservation, similar long term outcome studies should ultimately guide the resection strategy.

Imaging findings in a distinct lethal inherited arteriopathy syndrome associated with a novel mutation in the FBLN4 gene.

OBJECTIVES: We present the imaging findings of a newly identified lethal arteriopathy associated with a novel mutation in the gene encoding fibulin-4, occurring in a distinct community from southern India. MATERIAL AND METHODS: A total of 31 children from a distinct population subgroup who presented with characteristic arterial dilatation and tortuosity were studied. All children except one belonged to unrelated families from an ethno-religious group (Muslim) from the northern coastal belt of southern India. CT angiography was performed in 30 children and contrast MRA in one. RESULTS: Impressive dilatation and elongation of ascending aorta, arch, descending aorta and main pulmonary arteries with characteristic narrowing of aortic isthmus were seen in all patients. Stenosis of arch branches, abdominal visceral branches and pulmonary artery branches was observed in 21 (68%), 23 (62.5%) and 20 (65%) patients respectively. Genetic studies revealed an identical mutation in exon 7 of the FBLN4 gene. On follow-up, 27 of them had died before the age of 3 years and only two children were alive after the age of 4 years. CONCLUSIONS: FBLN4-associated vasculopathy is a highly lethal disease characterized by severe aneurysmal dilatation of thoracic aorta, its branches and pulmonary arteries with stenoses at typical locations. KEY POINTS: • Homozygous mutations in exon 7 of the FBLN4 gene can produce lethal vasculopathy. • Fibulin-4 is a critical determinant in human elastogenesis. • Imaging findings can give a clue to underlying connective tissue disorders.

Magnetic resonance functional nano-hydroxyapatite incorporated poly(caprolactone) composite scaffolds for in situ monitoring of bone tissue regeneration by MRI.

In this study, we have reported the incorporation of a multi-modal contrast agent based on hydroxyapatite nanocrystals, within a poly(caprolactone)(PCL) nanofibrous scaffold by electrospinning. The multifunctional hydroxyapatite nanoparticles (MF-nHAp) showed simultaneous contrast enhancement for three major molecular imaging techniques. In this article, the magnetic resonance (MR) contrast enhancement ability of the MF-nHAp was exploited for the purpose of potentially monitoring as well as for influencing tissue regeneration. These MF-nHAp containing PCL scaffolds were engineered in order to enhance the osteogenic potential as well as its MR functionality for their application in bone tissue engineering. The nano-composite scaffolds along with pristine PCL were evaluated physico-chemically and biologically in vitro, in the presence of human mesenchymal stem cells (hMSCs). The incorporation of 30-40 nm sized MF-nHAp within the nanofibers showed a substantial increase in scaffold strength, protein adsorption, proliferation, and osteogenic differentiation of hMSCs along with enhanced MR functionality. This preliminary study was performed to eventually exploit the MR contrast imaging capability of MF-nHAp in nanofibrous scaffolds for real-time imaging of the changes in the tissue engineered construct.

Role of 64-MDCT in evaluation of pulmonary atresia with ventricular septal defect.

OBJECTIVE: The purposes of this article are to describe the technical factors in performing 64-MDCT of pulmonary atresia with ventricular septal defect (PA-VSD), to describe the anatomic variations in pulmonary arterial circulation and other associated anomalies, and to describe the postoperative evaluation of this condition. CONCLUSION: The management of this complex condition has been largely determined by the morphology of pulmonary arteries and the extracardiac sources of pulmonary blood supply. Although echocardiography and catheter angiography are the traditional imaging techniques used to diagnose PA-VSD, 64-MDCT has become a valuable noninvasive imaging technique in comprehensive evaluation of this condition.