Exhibited Contrast Enhancement Research Articles

MRI characteristics and oncological follow-up of patients with ISUP grade group 4 or 5 prostate cancer

ObjectivesTo analyze multiparametric MRI (mpMRI) characteristics of patients with International Society of Urological Pathology (ISUP) grade group (GG) 4 or 5 prostate cancer (PC) and to correlate MRI parameters with the occurrence of biochemical recurrence (BCR) after radical prostatectomy (RPE).MethodsIn this single-center cohort study consecutive patients with mpMRI and ISUP GG 4 or 5 PC were retrospectively analyzed. Clinical, MR-guided biopsy, and diagnostic mpMRI parameter were assessed. A subcohort of patients with RPE and follow-up was analyzed separately. A univariate and multivariate analyses were performed to determine parameters that are associated to patients with BCR after RPE.Results145 patients (mean age 70y, median PSA 10.9 ng/ml) were analyzed. 99% had a PI-RADS classification of 4 or 5, 48% revealed MRI T3 stage, and median diameter of the MRI index lesion (IL) was 15 mm. IL showed a median ADC value of 668 ×10−6 mm2/s and exhibited contrast enhancement in 94% of the cases. For patients with follow-up after RPE (n = 82; mean follow-up time 68 ± 27 m), MRI parameters were significantly different for contact length of the IL to the pseudocapsule (LCC), MRI T3 stage, and IL localization (p < 0.05). Higher PSAD and MRI T3 stage were independent parameters for the risk of BCR when incorporating clinical, biopsy, and MRI parameters.ConclusionISUP GG 4 or 5 PC has distinctive characteristics on mpMRI and were detected on MRI in all cases. In addition, higher PSAD and MRI T3 stage were significant predictors for BCR after RPE.

A Rare Case of Intra-Renal Paraganglioma in a Child Masquerading as Renal Cell Carcinoma

Background: Renal cell carcinomas (RCCs) are rare in children, accounting for around 2% of all pediatric renal tumors. Paragangliomas are extra-adrenal locations of phaeochromocytomas. They originate from chromaffin cells arising along the sympathetic paraganglia and are secretory in most cases. Sequential imaging is often required to ascertain the etiology of a renal mass; ultrasound (USG), contrast-enhanced computerized tomography scan (CECT), and magnetic resonance imaging (MRI). Tissue diagnosis is confirmatory. Clinical Description: An 11-year-old girl presented with a right-sided abdominal and flank pain that was dull aching and nonradiating. She had no history of jaundice, hematuria, dysuria, bowel symptoms, sweating, palpitations, or syncope. The vitals were stable, without tachycardia or hypertension. No abnormal findings were found on clinical examination. Initially, the possibility of a renal stone was considered. Management and Outcome: Baseline blood tests were normal. Abdominal USG detected a heterogeneous mass in the right kidney. CECT ascertained that it was very vascular and exhibited contrast enhancement, suggesting a renal tumor. MRI showed that the right renal artery was acting as the feeding vessel to the tumor. RCC was suspected based on imaging. The vascular nature prevented us from performing a Tru-cut biopsy. A right-sided nephrectomy was planned, preceded by angiography and embolization of the right renal artery to reduce vascularity. Intraoperative episodes of hypertension were noted. Gross appearance suggested RCC; however, histopathology revealed evidence of an intrarenal PGL. Conclusions: Diagnosing a nonfunctional PGL in an asymptomatic patient is challenging and may only be possible by intraoperative histopathology.

Theranostic nanobubbles towards smart nanomedicines

Targeted therapy and early accurate detection of malignant lesions are essential for the effectiveness of treatment and prognosis in cancer patients. The development of gaseous system as a versatile platform for the fabricated nanobubbles, has attracted much interest in improving the efficacy of ultrasound therapeutic, diagnostic, and theranostic platforms. Nano-sized bubble, as an ultrasound contrast agent, with spherical gas-filled structures exhibited contrast enhancement capability due to their inherent EPR effect. Additionally, nanobubbles exhibited good stability with extended retention time in the blood stream. The current review summarized various nanobubbles and discussed about the crucial parameters affecting the stability of ultrafine bubbles. Furthermore, therapeutic and theranostic gaseous systems for fighting against cancer were described.

Self-assembled multifunctional nanotheranostics loading GEM for targeted lung cancer therapy.

The aim of this study was to prepare a promising drug carrier for treatment of lung cancer. The self-assembly nanoparticles of SDP-GEM/PEI-PEG-anti-EGFR with chemotherapeutic drug of gemcitabine (GEM), Magnetic resonance imaging (MRI) guided- imaging and targeting of anti- Epidermal Growth Factor Receptor (anti-EGFR) were designed. The imaging capacity, targeting feasibility and anti-tumor function were evaluated respectively. SDP-GEM/PEI-PEG-anti-EGFR exhibited contrast enhancement under T2 Weight Image (T2WI) and a liner relationship was found between the concentration and relaxation rate of R2 and R2* in vitro. With the targeting of anti-EGFR, the endocytosis of nanoparticles increased significantly, which effectively killed lung cancer cells in vitro, and importantly it can be accurately delivered to tumor site within 3h in vivo. Prolonged lifetime and smaller tumor volume demonstrated that SDP-GEM/PEI-PEG-anti-EGFR efficiently inhibited tumor growth in vivo. Therefore, SDP-GEM/PEI-PEG-anti-EGFR was an effective and safe drug carrier, which had a great potential application in MRI-guided lung cancer therapy.

NI-01 CONTRAST-ENHANCED MRI AND POSITRON EMISSION TOMOGRAPHY FOR DISTINGUISHING THE GRADE OF GLIOMA

OBJECTIVEGrading of glioma according to the WHO classification plays an important role in the treatment of patients with glioma. It is widely recognized that malignant gliomas exhibit contrast enhancement on MRI, whereas low-grade gliomas do not exhibit contrast enhancement. However, we sometimes encounter malignant gliomas without contrast enhancement on MRI. In this study, we evaluated the diagnostic accuracy of contrast-enhanced MRI and PET for distinguishing the WHO grade of glioma.METHODSA total of 105 patients with newly diagnosed cerebral glioma were included in the study. All patients underwent 11C-Methionine (MET), 11C-Choline (CHO), 18F-Fluorodeoxyglucose (FDG) PET and MRI. The specificity and sensitivity of MRI contrast enhancement and mean T/N ratios of these three tracers for each WHO grade were analyzed.RESULTSContrast enhancement was observed in 35 patients (33%) of the total. Contrast enhancement was observed in 1/30 (3%) in grade 2, 8/43 (19%) in grade 3, and 26/30 (87%) in grade 4. The sensitivity and specificity of MRI for differentiating grade 2 from grade 3 was 11.1% and 54.7%, respectively. In contrast, the cutoff value, sensitivity, and specificity of each tracer for differentiating grade 2 from grade 3 were: 1.70, 66.7%, and 58.1% for MET; 2.15, 76.7%, and 51.2% for CHO; and 0.64, 80.0%, and 32.6% for FDG, respectively. DISCUSSION: A correlation between contrast enhancement of MRI and WHO grade was observed to some extent; however, only 19% grade 3 gliomas showed contrast enhancement. The sensitivity and specificity of PET for differentiating between grade 2 and 3 was relatively higher than that of MRI; however, it was not suitable for clinical use.CONCLUSIONContrast-enhanced MRI may not be reliable for determining the WHO grade for glioma, in particular differentiating between grade 2 and 3. Comprehensive evaluation with MRI and PET can provide more accurate diagnosis.

Primary hepatic neuroendocrine tumor: A case report.

We herein present a case of an 87-year-old patient with multiple liver tumors identified on abdominal ultrasound. The assessment performed on admission included physical examination, computed tomography (CT) during hepatic angiography and CT during arterial portography. The examination revealed contrast enhancement of a proportion of the liver tumors (20 mm maximum diameter) during the arterial phase and mild contrast washout of those tumors during the delayed phase. On contrast-enhanced magnetic resonance imaging using gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid, certain liver tumors exhibited contrast enhancement during the early phase and contrast washout during the hepatocyte phase in both lobes. By contrast, no lesions were identified during positron emission tomography imaging of the liver. A liver biopsy was performed and immunohistochemical staining revealed enhanced expression of cytokeratin AE1/AE3, synaptophysin, chromogranin A and CD56 and no expression of hepatocyte antigen or CΚ7. The mindbomb E3 ubiquitin protein ligase-1 index was ~2% in most of the tumor. The liver tumors were finally diagnosed as multiple intrahepatic metastases from a primary hepatic neuroendocrine tumor (PHNET). The patient underwent transarterial chemoembolisation with a combination of miriplatin (84 mg) mixed with gelatin sponge particles and lipiodol. To the best of our knowledge, this is the first report of PHNET in an patient aged >85 years.

Imaging features of invasion and preoperative and postoperative tumor burden in previously untreated glioblastoma: Correlation with survival

Imaging features of invasion and preoperative and postoperative tumor burden in previously untreated glioblastoma: Correlation with survival

Radiation Retinopathy After Fractionated Stereotactic Conformal Radiotherapy for Primary Intraorbital Optic Nerve Sheath Meningioma

There are just two reported cases of radiation retinopathy after fractionated stereotactic radiotherapy (SFRT) for optic nerve sheath meningioma (ONSM) (1,2). We report a further case of radiation retinopathy secondary to fractionated stereotactic conformal radiotherapy (SCRT) for biopsy-proven ONSM. A 42-year-old woman developed increasing proptosis of the right eye. Visual acuity was 20/16 in both eyes. Color vision was normal and there was no relative afferent pupillary defect. Visual fields were normal. Hertel exophthalmometry disclosed 9 mm of right axial proptosis. Ophthalmoscopy was normal. MRI showed a well-demarcated round intraconal orbital mass that abutted the globe and exhibited contrast enhancement (Fig. 1). A biopsy of the tumor disclosed an epithelial membrane antigen (EMA)-positive meningothelial meningioma (Fig. 2).FIG. 1: Postcontrast TI axial MRI shows an enhancing mass in the intraconal space of the right orbit that abuts the globe.FIG. 2: Tumor biopsy specimen (hematoxylin and eosin) shows a syncytial growth pattern and no mitotic figures, consistent with a meningothelial meningioma, World Health Organization Grade 1.The patient underwent fractionated SCRT to a total dose of 54 Gy in 30 divided fractions of 1.8 Gy. The maximum dose to the posterior retina was 54 Gy. The anterior half of the retina received a dose of <16.2 Gy. Two years after completion of radiotherapy, several cotton wool spots were noted in the right posterior pole (Fig. 3). Visual acuity remained 20/16 in each eye. Blood glucose level and antinuclear antibody were normal.FIG. 3: A. Right fundus photograph taken 2 years after completion of radiotherapy shows multiple cotton wool spots and a retinal hemorrhage inferior to the fovea, findings consistent with radiation retinopathy. B. Right fundus fluorescein angiogram shows late perivenous staining.A retinal fluorescein angiogram showed areas of capillary closure, microaneurysms, and venous staining in the right fundus (Fig. 3). Visual acuity dropped over the next 6 months to 20/40, and new blot hemorrhages were noted, but no edema or proliferative changes were seen. In the first reported case of radiation retinopathy after SFRT for ONSM (1), the patient received the same treatment as did our patient: 30 fractions of 1.8 Gy for a total dose of 54 Gy. The posterior retina received 27-48 Gy. Fluorescein angiography showed findings similar to those of our patient. These changes worsened over the next few months despite laser photocoagulation. The second report consisted of a letter by Levi (2) about a 57-year-old man diagnosed with optic nerve sheath meningioma who underwent SFRT with the same tumor dose (2). Five years after treatment, visual acuity dropped, and fluorescein angiography showed findings similar to those of our patient. Our case differs from the two previously reported cases in that the diagnosis was biopsy-proven and that 3D conformal methods were used to minimize collateral radiation damage. Many patients have now received radiotherapy for ONSM, and this is only the third reported case of radiation retinopathy. Our patient may have been relatively more vulnerable to radiation retinopathy because of the biopsy and the fact that the treatment field included the posterior retina, as in the case reported by Subramanian et al (1). In the case reported by Levi (2), the radiation dose to the posterior retina and the proximity of the tumor to the globe were not mentioned. Whether ONSM would respond to doses lower than 54 Gy in 30 fractions (the standard dose) is not known. It may be prudent to examine the possibility of treatment using a lower radiation dose, particularly for ONSMs that abut the globe. Radhika Krishnan, MA (Cantab), MRCOphth Indu Kumar, MRCOphth Graham Kyle, FRSCEd, FRCOphth Ophthalmology Department Walton Daycase and Outpatient Centre University Hospital Aintree Liverpool, UK [email protected] David John Husband, MRCP (UK), FRCR Clatterbridge Centre for Oncology Bebington, Cheshire, UK

P.382 Trends in mortality from liver cancer in the USA, 1993–2002

With evolving radio frequency technology, the clinical application of radio frequency ablation (RFA) has been actively investigated in the treatment for small renal tumors. We present our intermediate patient outcomes after RFA.Since January 2001, 17 patients with a total of 24 hereditary renal tumors ranging from 1.2 to 2.85 cm were treated with RFA using the 200 W Cool-tip RF System (Radionics, Burlington, Massachusetts) under laparoscopic (9) or percutaneous (8) guidance and had a minimum 1-year followup. A percutaneous approach was considered unsuitable if kidney tumors were contiguous to bowel, ureter or large vessels. Treatment eligibility criteria included an average tumor diameter of less than 3.0 cm, tumor growth during 1 year and solid appearance with contrast enhancement (HU change greater than 20) on computerized tomography (CT). Postoperative followup consisted of CT with and without intravenous contrast, and renal function assessment at regular intervals.Median patient age was 38 years (range 20 to 51). At a median followup of 385 days (range 342 to 691), median tumor or thermal lesion diameter decreased from 2.26 to 1.62 cm (p = 0.0013), and only 1 lesion (4%), which was located centrally near the hilum, exhibited contrast enhancement (HU change greater than 10) on CT at 12 months. Of the 15 renal tumors ablated laparoscopically, 13 were in direct contact with the bowel and 2 were abutting the ureter, necessitating mobilization before RFA. Laparoscopic ultrasound was used to guide radio frequency electrode placement and monitor the ablation process in these cases. Operative time and intraoperative blood loss (mean ± standard mean of error) were 243 ± 29 minutes and 67 ± 9 cc, respectively. In 1 patient whose ureter was adherent to the tumor a ureteropelvic junction obstruction developed after laparoscopic RFA, requiring open repair.At the minimum 1-year followup 23 of 24 ablated tumors lacked contrast uptake on CT, meeting our radiographic criteria of successful RFA treatment. RFA treatment of small renal tumors using the Radionics system appears to result in superior treatment outcomes compared to those of earlier series with lower radio frequency power generators. A high wattage generator might attain more consistent energy deposition with subsequent cell death in the targeted tissue due to less convective heat loss.

Natural history of neurofibromatosis 1–associated optic nerve glioma in mice

Children affected with the inherited tumor predisposition syndrome, neurofibromatosis 1 (NF1), are prone to the development of low-grade astrocytic optic pathway tumors (optic pathway glioma [OPG]). Previously, we developed a model of NF1-associated astrocytoma (GFAPCre; Nf1(flox/mut) mice) in which mice develop optic nerve and chiasm glioma. To define the molecular pathogenesis of OPG, we used this mouse model to study the natural history of OPG formation using immunohistological and radiographic approaches. We observed that whereas astrocyte hyperplasia is present in the optic nerves associated with gross optic nerve thickening at 3 weeks of age, overt neoplastic changes were not seen until 2 months of age. Astrocyte proliferation was maximal between 3 weeks and 2 months of age, suggesting that the most rapid period of growth occurs early. Mouse OPG tumors were detected by magnetic resonance imaging at 2 months of age and exhibited contrast enhancement, as seen in human OPG. In addition, the mouse OPG tumors exhibited expression of proteins associated with astroglial progenitors, including nestin and brain lipid binding protein. Last, we observed neovascularization and microglial cell infiltration by 3 weeks of age before overt neoplastic transformation, suggesting that these cellular changes participate in the early stages of tumor formation.

Radio Frequency Ablation of Small Renal Tumors: Intermediate Results

With evolving radio frequency technology, the clinical application of radio frequency ablation (RFA) has been actively investigated in the treatment for small renal tumors. We present our intermediate patient outcomes after RFA. Since January 2001, 17 patients with a total of 24 hereditary renal tumors ranging from 1.2 to 2.85 cm were treated with RFA using the 200 W Cool-tip RF System (Radionics, Burlington, Massachusetts) under laparoscopic (9) or percutaneous (8) guidance and had a minimum 1-year followup. A percutaneous approach was considered unsuitable if kidney tumors were contiguous to bowel, ureter or large vessels. Treatment eligibility criteria included an average tumor diameter of less than 3.0 cm, tumor growth during 1 year and solid appearance with contrast enhancement (HU change greater than 20) on computerized tomography (CT). Postoperative followup consisted of CT with and without intravenous contrast, and renal function assessment at regular intervals. Median patient age was 38 years (range 20 to 51). At a median followup of 385 days (range 342 to 691), median tumor or thermal lesion diameter decreased from 2.26 to 1.62 cm (p = 0.0013), and only 1 lesion (4%), which was located centrally near the hilum, exhibited contrast enhancement (HU change greater than 10) on CT at 12 months. Of the 15 renal tumors ablated laparoscopically, 13 were in direct contact with the bowel and 2 were abutting the ureter, necessitating mobilization before RFA. Laparoscopic ultrasound was used to guide radio frequency electrode placement and monitor the ablation process in these cases. Operative time and intraoperative blood loss (mean +/- standard mean of error) were 243 +/- 29 minutes and 67 +/- 9 cc, respectively. In 1 patient whose ureter was adherent to the tumor a ureteropelvic junction obstruction developed after laparoscopic RFA, requiring open repair. At the minimum 1-year followup 23 of 24 ablated tumors lacked contrast uptake on CT, meeting our radiographic criteria of successful RFA treatment. RFA treatment of small renal tumors using the Radionics system appears to result in superior treatment outcomes compared to those of earlier series with lower radio frequency power generators. A high wattage generator might attain more consistent energy deposition with subsequent cell death in the targeted tissue due to less convective heat loss.

Feasibility of synchrotron radiation computed tomography on rats bearing glioma after iodine or gadolinium injection. Jeune Equipe RSRM-UJF.

The purpose of this work was to demonstrate the feasibility of a new imaging technique called synchrotron radiation computed tomography (SRCT). This technique leads to a direct assessment of the in vivo concentration of an iodine- or gadolinium-labeled compound. Rats bearing C6 glioma were imaged by MRI prior to the SRCT experiment. The SRCT experiments were performed after a 1.3 g I/kg (n = 5) or a 0.4 g Gd/kg (n = 5) injection. Finally, brains were sampled for histology. The SRCT images exhibited contrast enhancement at the tumor location. Ten minutes after injection, iodine and gadolinium tissular concentrations were equal to 0.80 ( +/- 0.40) mg/cm3 and 0.50 ( +/- 0.10) mg/cm3, respectively in the peripheral area of the tumor (respective background value: 0.20 +/- 0.02 to 0.10 +/- 0.01). Correlation to MRI and histology revealed that the contrast uptake occurred in the most vascularized area of the tumor. The present study summarizes the feasibility of in vivo SRCT to obtain quantitative information about iodine and gadolinium-labeled compounds. Beyond brain tumor pathology, the SRCT appears as a complementary approach to MRI and CT, for studying iodine- and gadolinium-labeled compounds by the direct achievement of the tissular concentration value in the tissue.

High Resolution Gd-DTPA MR Imaging of the Inner Ear in 60 Patients with Idiopathic Vestibular Neuritis: No Evidence for Contrast Enhancement of the Labyrinth or Vestibular Nerve

Sixty patients with acute idiopathic vestibular neuritis (confirmed by clinical examination and caloric irrigation) were evaluated in a prospective study by high resolution magnetic resonance imaging (hr-MRI) between days 3 and 30 after onset of symptoms. We used a 1.5 Tesla imager with an axial and coronal T1-weighted 2D-fast low angle shot-, T2-weighted turbo spin echo-, and an axial T2-weighted 3D-constructive interference in steady-state sequence for MRI. None of the patients' MRIs exhibited contrast enhancement of the labyrinth, vestibulocochlear nerve, or vestibular ganglion, even when high doses of gadolinium (0.2 mmol/kg) were used. In contrast, several previous studies demonstrated contrast enhancement of the vestibulocochlear nerve/labyrinth in herpes zoster oticus, labyrinthitis, and Cogan's syndrome or of the facial nerve in Bell's palsy. On the basis of our MRI findings, we speculate that idiopathic vestibular neuritis is neither a viral infection directly affecting the nerve (such as herpes zoster) nor a labyrinthitis. An autoimmunological disease of the labyrinth, which should involve only the anterior and horizontal semicircular canals, is also unlikely. A subacute reactivation of a latent viral infection--as discussed for Bell's palsy--is compatible with our MRI findings. The observed differences between contrast enhancement of the facial nerve in Bell's palsy and the vestibulocochlear nerve in vestibular neuritis may be due to their dissimilar anatomy: contrary to the vestibular nerve, the facial nerve has very prominent circumneural arteriovenous structures. Hyperemia within these vascular structures may cause the contrast enhancement seen in Bell's palsy.

Computed tomography and histologic limits in glial neoplasms: tumor types and selection for volumetric resection.

Selective and accurate resection of any computed tomography (CT) or magnetic resonance imaging (MRI) defined intracranial volume is possible by employing imaging-based computer-assisted volumetric stereotactic methods. Although the target volume can be any intracranial lesion, volumetric resection techniques were most frequently applied to the most commonly referred intraaxial lesions: glial neoplasms located in eloquent brain regions. Requirements for understanding of glial neoplasms as target volumes prompted investigations of the three-dimensional spatial configuration of these lesions, their histologic margins, and the accuracy with which these margins could be detected on CT and MRI. Stereotactic serial biopsy studies have shown that glial neoplasms frequently comprise two elements: tumor tissue and isolated tumor cells which infiltrate brain parenchyma. The tumor tissue component of high grade gliomas is most accurately defined by the volume which exhibits contrast enhancement. However, tumor tissue in low grade (nonpilocytic) gliomas is usually indistinguishable from infiltrated parenchyma on CT and MRI; both are hypodense on CT and do not usually exhibit contrast enhancement. Stereotactic serial biopsy is the only reliable method by which CT hypodense tumor tissue can be differentiated from infiltrated parenchyma in low grade (nonpilocytic) astrocytomas, oligodendrogliomas, and mixed gliomas. Stereotactic volumetric resection of infiltrated parenchyma defined by CT/MRI is advisable only in nonessential brain regions. In eloquent brain areas, stereotactic resection is appropriate for the glial tumor tissue component of high grade glial neoplasms, pilocytic astrocytomas, and low grade CT hypodense gliomas in which a stereotactic serial biopsy procedure has confirmed tumor tissue only.

Trochlear Nerve Neurinoma

A 43-year-old male presented with a low-density mass on computed tomographic scans; the mass did not exhibit contrast enhancement. The tumor was subtotally removed, and the intraoperative diagnosis was trochlear nerve neurinoma. Six other cases have been reported. The characteristic symptoms and signs of this tumor appear to be unusual facial sensations and signs of brain stem compression rather than trochlear nerve palsy.

Intracranial infection in cardiac transplant recipients.

Infections have produced most of the deaths in the Stanford cardiac transplant program. Of the first 182 transplant recipients, 27 developed nonviral intracranial infections: meningoencephalitis/abscess in 16 patients, meningitis in 9, and rhinocerebral phycomycoses in 2. The responsible organisms included aspergillus, toxoplasma, candida, klebsiella, cryptococcus, coccidioides, listeria, mucor, and rhizopus. Characteristically, the areas of meningoencephalitis and abscesses were multiple and deep seated. Intracranial infections were invariably associated with pulmonary or disseminated infection with same organism. Computed tomographic (CT) brain scans in patients with meningoencephalitis often showed minimal, nonspecific, low-density lesions which usually did not exhibit contrast enhancement. At surgery the lesions were found to differ from typical pyogenic abscesses in that capsules were not well developed, and the aspirate consisted of necrotic fragments of edematous white matter and inflammatory cells rather than liquefied pus. Aspergillus infections of the central nervous system usually developed within the first three months after transplantation. Cases of meningitis occurred at variable times after transplantation, but approximately half appeared within 30 days after immunosuppressive therapy for treatment of rejection was increased. The prognosis for brain abscess depended on the causative organism. All patients with aspergillus infection died despite treatment with amphotericin B. The toxoplasma abscess responded to a combination of sulfadiazine and pyrimethamine. Meningitis was successfully suppressed or cured with appropriate treatment except for 1 patient with disseminated cryptococcosis.