The utility of arterial spin labeling imaging for predicting prognosis after a recurrence of high-grade glioma in patients under bevacizumab treatment.

BACKGROUND AND PURPOSE: Currently, the antiangiogenic agent bevacizumab (BVZ) is used as a treatment option for high-grade glioma (HGG) patients. However, BVZ restores disruptions of the blood-brain barrier, which leads to the disappearance of contrast enhancement during radiological examinations and therefore complicates evaluations of treatment efficacy. This study aimed to investigate the radio-morphological features of recurrent lesions that newly appeared under BVZ therapy, as well as the utility of arterial spin labeling (ASL) perfusion imaging for evaluating treatment response and prognosis in HGG patients receiving BVZ. METHODS: Thirty-two patients (20 males, 12 females; age range, 35-84 years) with HGG who experienced a recurrence under BVZ therapy were enrolled. We measured the relative cerebral blood flow (rCBF) values of each recurrent lesion using ASL, and retrospectively investigated the correlation between rCBF values and prognosis. RESULTS: The optimal rCBF cut-off value for predicting prognosis was defined as 1.67 using receiver operating characteristic curve analysis. The patients in the rCBF < 1.67 group had significantly longer overall survival (OS) and post-progression survival (PPS) than those in the rCBF ≥ 1.67 group (OS: 34.0 months vs. 13.0 months, p = 0.03 and PPS: 13.0 months vs. 6.0 months, p < 0.001, respectively). CONCLUSION: The ASL-derived rCBF values of recurrent lesions may serve as an effective imaging biomarker for prognosis in HGG patients undergoing BVZ therapy. Low rCBF values may indicate that BVZ efficacy is sustainable, which will influence BVZ treatment strategies in HGG patients.

Usefulness of the Lone Star Retractor System for harvesting the superficial temporal artery: technical note.

Harvesting the superficial temporal artery (STA) is the first difficult step in extracranial-intracranial bypass surgery. There are various methods and instruments for harvesting the STA. We used the Lone Star (LS) retractor system for harvesting the STA. The LS retractor system is used in other surgical specialties. The LS retractor system consists of the retractor ring (14.1 cm × 14.1 cm) and elastic stays (5-mm sharp hook). The retractor ring can be used to adjust to the operative field. Retracting the loose connective tissue around the STA by the elastic stays can make harvesting the STA easy and safe. After harvesting the STA, retracting the skin and muscle by the elastic stays is useful for hemostasis during intracranial surgery and anastomosis. We used the LS retractor system in 26 consecutive patients to perform STA-MCA anastomosis between November 2015 and August 2018. All STAs were harvested without complications or injuries. The LS retractor system is a safe and useful method for harvesting the STA.

Utility of follow-up ultra-high-resolution CT angiography with model-based iterative reconstruction after flow diverter treatment for cerebral aneurysms.

PURPOSE: Follow-up examinations after flow diverter (FD) treatment for cerebral aneurysms typically involve magnetic resonance imaging (MRI) or digital subtraction angiography (DSA). However, MRI is prone to vascular defects due to metal artifacts from FD, and DSA carries a risk of ischemic complications. In the context of computed tomography angiography (CTA), this study compares the efficacy of ultra-high-resolution CT (UHRCT) and novel reconstruction techniques, such as model-based iterative reconstruction (MBIR), against conventional methods such as filtered back projection (FBP) and hybrid iterative reconstruction (IR), to determine if they are a viable alternative to DSA in clinical settings. MATERIALS AND METHODS: A phantom study was conducted with the full-width half-maximum considered as the FD thickness. This study compared three reconstruction methods: MBIR, FBP, and hybrid IR. A clinical study was also conducted with 21 patients who underwent follow-up CTA after FD treatment. The FD's visibility was assessed using a 4-point scale in FBP, hybrid IR, and MBIR compared to cone-beam CT (CBCT) with angiographic systems. RESULTS: In the phantom study, FBP, hybrid IR, and MBIR visualized thinner FD thicknesses and improved detail rendering in that order. MBIR proved to be significantly superior in both the phantom and clinical study. CONCLUSION: UHRCT with MBIR is highly effective for follow-up evaluations after FD treatment and may become the first-choice modality in the future.

[Neuroimaging of Pituitary Neuroendocrine Tumors].

Magnetic resonance imaging(MRI)is the preferred imaging technique for sellar and parasellar regions. In this study, we report our clinical experience with MRI for pituitary neuroendocrine tumors(PitNETs)with reference to histopathological findings through a review of the literature. Our previous study indicated that the three dimensional-spoiled gradient echo(3D-SPGR)sequence is suitable for evaluating sellar lesions on a postcontrast T1 weighted image(T1WI). This image demonstrates a defined relationship between the tumor and its surroundings, such as the normal pituitary gland, cavernous sinus, and optic pathway. This 3D-SPGR sequence is also suitable for detecting microtumors in corticotroph PitNETs. In somatotroph PitNETs, the signal intensity on T2WI is important to differentiate densely granulated tumors from sparsely granulated somatotroph tumors. In lactotroph PitNETs, distinct hypointense areas in the early phase on T2WI, possibly due to diffuse hemorrhage, indicate pronounced regression of invasive macroprolactinomas during cabergoline therapy.

[Overview of the New World Health Organization Classification of Pituitary Neuroendocrine Tumors].

The 5th edition of the World Health Organization(WHO)classification of endocrine and neuroendocrine tumors was revised in 2022. A major nomenclature change was from "adenoma" to "pituitary neuroendocrine tumor"(PitNET). Tumors are classified based on the cell lineage as determined by expression of transcription factors, such as, PIT1, TPIT, and SF1. Therapeutic modalities available for management of functioning PitNETs include surgery, medical treatment, and irradiation. Transsphenoidal surgery is the gold-standard surgical treatment. The aim of the present study was to summarize changes from the previous edition of the WHO classification and discuss topics regrading PIT1, TPIT, and SF1-lineage PitNETs with reference to clinicopathological findings.

A case of intracranial myxoid mesenchymal tumor with EWSR1:CREM fusion in an adult female: Extensive immunohistochemical evaluation.

Intracranial myxoid mesenchymal tumor (IMMT) is a recently described, extremely rare group of neoplasms characterized by fusions between the female-expressed transcript (FET) family genes and the cAMP response element-binding protein (CREB) family genes. Controversy persists regarding whether the tumor is a myxoid variant of angiomatoid fibrous histiocytoma or a completely distinct clinicopathological entity. Here, we report a case of IMMT arising in the posterior fossa in a 65-year-old woman with a history of breast cancer. We performed total removal of the tumor, which histologically demonstrated features characteristic of IMMT but also bore a partial resemblance to conventional angiomatoid fibrous histiocytoma. Immunohistochemically, tumor cells were diffusely positive for desmin, vimentin, cluster of differentiation (CD) 99 (CD99), glucose transporter-1, and cytokeratin (CK) 8/18 (CK8/18), and focally positive for CK7, epithelial membrane antigen, mucin 4, anaplastic lymphoma kinase, calponin, and CD68. Molecular genetic analysis revealed a fusion between the Ewing sarcoma breakpoint region 1 (EWSR1) gene (EWSR1) and the cAMP-responsive element modulator (CREM) gene (CREM) called EWSR1:CREM fusion, which confirmed the diagnosis. The overlap of the pathological features of IMMTs and angiomatoid fibrous histiocytomas may support the recent theory that these tumors are two manifestations of a single entity. Moreover, our study indicated the broad spectrum of immunohistochemical phenotypes of these tumors, which should be noted during diagnosis. Further studies are needed to elucidate the histopathological concept, long-term prognosis, optimal treatment strategy, and factors associated with the prognosis and therapeutic options of this condition.

Low signal intensities of MRI T1 mapping predict refractory diplopia in Graves' ophthalmopathy.

OBJECTIVE: In Graves' ophthalmopathy (GO), fibrosis in extraocular muscles (EOMs) may be related to intravenous glucocorticoid (ivGC)-resistant diplopia. Signal intensity (SI) of magnetic resonance imaging (MRI) T1 mapping can quantify properties of EOM components, including fibrosis. We investigated EOM features of GO patients with diplopia using T1 mapping SI and the predictive value of T1 mapping SI in the response of diplopia to ivGCs. DESIGN: We performed a cross-sectional study that included 13 active GO patients, 34 inactive GO patients with history of diplopia, including 20 with a history of diplopia disappearance, 14 GO patients with refractory diplopia and 35 control subjects. In nine active GO patients, the relationship between T1 mapping SI at pretreatment and at diplopia outcome after ivGC treatment was prospectively investigated. METHODS: T1 mapping SI of left and right inferior rectus and medial rectus muscles was measured in all participants. RESULTS: T1 mapping SI in inactive GO patients with refractory diplopia was significantly lower than that of other groups in all evaluated EOMs. Diagnostic accuracy for refractory diplopia by T1 mapping SI in GO patients with a history of diplopia disappearance was excellent (AUC 0.89) compared with other assessments. Furthermore, among nine active GO patients, pretreatment T1 mapping SI in four patients with ivGC-resistant diplopia tended to be low compared with the other five patients with improved diplopia. CONCLUSIONS: Low intensity T1 mapping in EOMs is likely to be associated with refractory diplopia and may be useful in predicting the response of diplopia to ivGCs.

Successful reduction of ACTH secretion in a case of intractable Cushing's disease with pituitary Crooke's cell adenoma by combined modality therapy including temozolomide.

Crooke's cell adenoma (CCA) is an aggressive subtype of corticotroph adenoma; however, CCA is associated with a high incidence of low expression of methyl guanine methyl transferase (MGMT), suggesting that temozolomide (TMZ) treatment might be effective for this tumor type. The case of a 56-year-old woman with Cushing's disease caused by a pituitary CCA is presented. At the age of 38 years, the patient presented to our hospital with polyuria and a visual field defect. MRI and laboratory studies showed a 4.5-cm-diameter pituitary tumor with plasma adrenocorticotropic hormone (ACTH) and serum cortisol levels of more than 500 pg/mL and 40 µg/dL, respectively. At 39 years of age, the patient underwent a craniotomy, and her plasma ACTH and cortisol levels decreased to less than 200 pg/mL and 10 µg/dL, respectively; however, these hormone levels increased gradually to 3,940 pg/mL and 70 µg/dL, respectively, by the time the patient was 56 years old. Histopathological re-examination of the previously resected specimen showed that the pituitary tumor was MGMT-negative CCA. TMZ treatment after the second operation decreased the plasma ACTH levels from 600-800 pg/mL to 70-300 pg/mL. No signs of recurrence were observed in the seven years following these treatments with added prophylactic radiation therapy. These clinical findings suggest that TMZ treatment to patients with CCA accompanied with elevated ACTH may be good indication to induce lowering ACTH levels and tumor shrinkage.

Utility of intravoxel incoherent motion magnetic resonance imaging and arterial spin labeling for recurrent glioma after bevacizumab treatment.

Background Detecting recurrence of glioma on magnetic resonance imaging (MRI) is getting more and more important, especially after administration of new anti-tumor agent. However, it is still hard to identify. Purpose To examine the utility of intravoxel incoherent motion (IVIM) MRI and arterial spin labeling-cerebral blood flow (ASL-CBF) for recurrent glioma after initiation of bevacizumab (BEV) treatment. Material and Methods Thirteen patients (7 men, 6 women; age range = 41-82 years) with glioma (high grade, n = 11; low grade, n = 2) were enrolled in the study. IVIM parameters including apparent diffusion coefficient (ADC), true diffusion coefficient (D), and perfusion fraction (f) were obtained with 14 different b-values. We identified tumor progression during BEV therapy by MRI monitoring consisting of diffusion-weighted imaging (DWI), fluid-attenuated inversion recovery (FLAIR) imaging, and contrast-enhanced T1-weighted (CE-T1W) imaging by measuring tumor area. We also measured each parameter of IVIM and ASL-CBF, and calculated relative ADC (rADC), relative D (rD), relative f (rf), and relative CBF (rCBF) by obtaining the ratio between each area and the contralateral cerebral white matter. We calculated the rate of change (Δ) by subtracting values from those from the preceding MRI study, and obtained Spearman's rank correlation coefficient (rs). Results Tumor progression was identified in nine patients (high grade, n = 7; low grade, n = 2). Negative correlations were identified between ΔrD and ΔDWI area (rs = -0.583), and between ΔrD and ΔCE-T1W imaging area (rs = -0.605). Conclusion Tumor progression after BEV treatment can be identified by decreasing rD.

Reduction of metal artifacts due to dental hardware in computed tomography angiography: assessment of the utility of model-based iterative reconstruction.

PURPOSE: The aim of this study is to assess the value of adaptive statistical iterative reconstruction (ASIR) and model-based iterative reconstruction (MBIR) for reduction of metal artifacts due to dental hardware in carotid CT angiography (CTA). METHODS: Thirty-seven patients with dental hardware who underwent carotid CTA were included. CTA was performed with a GE Discovery CT750 HD scanner and reconstructed with filtered back projection (FBP), ASIR, and MBIR. We measured the standard deviation at the cervical segment of the internal carotid artery that was affected most by dental metal artifacts (SD1) and the standard deviation at the common carotid artery that was not affected by the artifact (SD2). We calculated the artifact index (AI) as follows: AI = [(SD1)2 - (SD2)2]1/2 and compared each AI for FBP, ASIR, and MBIR. Visual assessment of the internal carotid artery was also performed by two neuroradiologists using a five-point scale for each axial and reconstructed sagittal image. The inter-observer agreement was analyzed using weighted kappa analysis. RESULTS: MBIR significantly improved AI compared with FBP and ASIR (p < 0.001, each). We found no significant difference in AI between FBP and ASIR (p = 0.502). The visual score of MBIR was significantly better than those of FBP and ASIR (p < 0.001, each), whereas the scores of ASIR were the same as those of FBP. Kappa values indicated good inter-observer agreements in all reconstructed images (0.747-0.778). CONCLUSIONS: MBIR resulted in a significant reduction in artifact from dental hardware in carotid CTA.

Carotid Plaque Evaluation Using Gemstone Spectral Imaging: Comparison with Magnetic Resonance Angiography.

BACKGROUND: The present study compared the applicability of computed tomography carotid plaque imaging using effective Z maps with gemstone spectral imaging (GSI) to that of magnetic resonance plaque imaging using 3-dimensional time-of-flight magnetic resonance angiography. METHODS: Stenosis was assessed in 18 carotid arteries of 14 patients, and the effective Z values of noncalcified carotid plaques were compared with the signal intensities of magnetic resonance angiography. RESULTS: It was found that the effective Z value of noncalcified carotid plaques was significantly lower for a group with high signal intensity than for a group with low signal intensity on magnetic resonance angiography (P <.001). The area under the receiver operating characteristic curve of effective Z values was .975, and the presumed cutoff effective Z value required to discriminate low and high intensity plaques on magnetic resonance angiography was 7.83. CONCLUSIONS: The effective Z value generated by GSI is a useful parameter to detect vulnerable carotid plaque materials.

Transbrachial Mechanical Thrombectomy for Acute Ischemic Stroke in Marfan's Syndrome: A Case Report.

Objective: Marfan's syndrome (MFS) is a systemic connective tissue disorder with autosomal dominant inheritance. Cardiovascular complications of MFS such as aortic root or valve disease and aortic aneurysm or dissection are potential cause of access route problems of mechanical thrombectomy (MT) for acute ischemic stroke (AIS). Here, we report a case of a patient with MFS who underwent MT for AIS. Case Presentation: A 58-year-old woman with MFS presented with a sudden onset of consciousness disturbance and right hemiparesis, and was referred to our hospital. After the infusion of tissue plasminogen activator, CTA showed a type III arch in the aortic arch and severe tortuosity of the thoracoabdominal aorta; thus, angiography was performed using the transbrachial approach. Left common carotid angiogram showed complete recanalization of the left middle cerebral artery. On the sixth day, the patient presented a sudden consciousness disturbance and left hemiparesis. MRA showed right internal carotid artery occlusion. MT was performed by the transbrachial approach, and complete recanalization was achieved on the first pass. Conclusion: MT via the transbrachial approach is a treatment option that should be considered, especially in MFS, where the transfemoral approach is difficult due to anatomical problems.

Papillary Glioneuronal Tumor Masquerading as Malignant Brain Tumors: A Case Report.

Papillary glioneuronal tumor (PGNT) is a low-grade biphasic tumor that is composed of glial fibrillary acidic protein (GFAP)-positive glial cells and synaptophysin-positive neurons. We report a case of PGNT occurring in the right occipital lobe of a 48-year-old woman who presented with acute headache and left homonymous hemianopsia, the latter of which was difficult to distinguish from malignant brain tumors because of peritumoral brain edema, intratumoral hemorrhage, and intraoperative fluorescence staining. PGNT should be included as one of the differential diagnoses in cases where the tumor shows hemorrhagic change despite decreased perfusion in arterial spin labeling MRI.

Experience of Cadaver Donor Nephrectomy with Cadaver Surgical Training.

As cadaver donor nephrectomy in kidney transplantation is performed in only a limited number of cases, few physicians are skilled in the surgical technique. We performed two cadaver donor nephrectomy sessions during cadaver surgical training. The first session was performed by a lecturer who was skilled in the technique, with physicians and nurses participating in order to learn the methodology. The second session was conducted only for physicians. The procedures undertaken were as follows: cannulation of the femoral artery and vein, skin incision and bowel ligation, cross-clamping of the aorta, diaphragmatic incision and inferior vena cava incision, dissection of the aorta and inferior vena cava, and nephrectomy. Although there were some differences from that normally observed in actual patient surgery, such as no bleeding and formalin fixation, some of the procedures were very useful in helping to better understand cadaver donor nephrectomy.

Endovascular Mechanical Thrombectomy with a Large-Bore Aspiration Catheter and Stent Retriever for Cerebral Venous Sinus Thrombosis in Pregnancy: A Case Report.

Objective: A case of cerebral venous sinus thrombosis (CVST) during pregnancy effectively recanalized by endovascular mechanical thrombectomy with the combined use of an aspiration catheter and a stent retriever is reported. Case Presentation: A 27-year-old woman at eight weeks' gestation developed sudden onset of right hemiparalysis and seizures and was referred to our hospital. Her National Institutes of Health Stroke Scale score on admission was 23. On MRI, diffusion-weighted imaging showed a hyperintensity area in the left frontal lobe, and T2* imaging showed hemorrhagic infarction in the same area. MR venography showed obstruction of the anterior two-thirds of the superior sagittal sinus (SSS). Anticoagulant therapy with heparin was started, but since the venous return was expected to be severely impaired, mechanical thrombectomy by endovascular surgery was selected, hoping to resolve symptoms early. Using a large-bore aspiration catheter in combination with a stent retriever, it was possible to safely guide the aspiration catheter into the anterior half of the SSS. The use of a large-bore aspiration catheter enabled retrieval of a large amount of thrombus in a short time, and complete recanalization was achieved. The patient's hemiplegia and aphasia improved significantly within a week after the procedure, and she was discharged without sequelae. Conclusion: Mechanical endovascular therapy of CVST performed with a combination of a large-bore aspiration catheter and a stent retriever should be considered particularly for patients with severe neurological symptoms or intracranial hemorrhage and for those who do not respond to anticoagulation therapy.

Laparoscopic pelvic lymph node dissection in cadaver surgical training from the combined perspectives of urologists, gastroenterologists and gynecologists improves overall knowledge and technique: initial experience of multidisciplinary cadaver surgical training at a single institution in Japan.

Surgeons in Japan have recently become more familiar with cadaver surgical training (CST). Extended pelvic lymph node dissection (PLND) considering the vesicohypogastric fascia and ureterohypogastric nerve fascia is gradually being performed not only in urology, but also in gynecology and gastroenterology. We performed CST using a 76-year-old female cadaver who was fixed by the Thiel method, with the aim of confirming the differences in the extent of PLND performed by certified laparoscopic specialists in urology, gastroenterology and gynecology. Even in the common surgeries, there are still several areas where anatomical structures are poorly understood. In recent years, with the spread of robotic surgery, the techniques related to PLND in these three departments have gradually become similar. Through this CST program, we were able to understand the differences in procedures and the extent of PLND in these three departments. By continuing these CSTs, we hope that a standardized PLND procedure will be performed not only within the same department, but also between different departments, and that high-quality PLND will be safely performed.

Up-To-Date Magnetic Resonance Imaging Findings for the Diagnosis of Hypothalamic and Pituitary Tumors.

Magnetic resonance imaging (MRI) is the preferred imaging technique for the sellar and parasellar regions. In this review article, we report our clinical experience with MRI for hypothalamic and pituitary lesions, such as pituitary adenomas, craniopharyngiomas, Rathke cleft cysts, germinoma, and hypophysitis with reference to the histopathological findings through a review of the literature. Our previous study indicated that three dimensional-spoiled gradient echo sequence is a more suitable sequence for evaluating sellar lesions on postcontrast T1 weighted image (WI). This image demonstrates the defined relationship between the tumor and its surroundings, such as the normal pituitary gland, cavernous sinus, and optic pathway. We demonstrated the characteristic MRI findings of functioning pituitary adenoma. In growth hormone-producing adenoma, signal intensity on T2WI is important to differentiate densely from sparsely granulated somatotroph adenomas. In prolactin-producing pituitary adenomas, distinct hypointense areas in early phase on T2WI, possibly owning to diffuse hemorrhage, indicate pronounced regressions of invasive macroprolactinomas during cabergoline therapy. The two histopathological subtypes, adamantinomatous and squamous papillary craniopharyngioma, differ in genesis. Calcified tumors are mostly adamantinomatous type. On MRI, these lesions have a heterogenous appearance with a solid portion and cystic components. The solid portions and cyst wall enhance heterogeneously. Although cyst fluid of Rathke cleft cysts show variable intensities on MRI, intracystic waxy nodule can be hypointense on T2WI. The enhancing cyst wall may contain the squamous metaplasia. Cystic lesions of the sellar and parasellar areas may be difficult to differentiate on a clinical, imaging, or even histopathological basis.

A New Method of Microcatheter Heat-Forming for Cerebral Aneurysmal Coiling Using Stereolithography Three-Dimensional Printed Hollow Vessel Models.

BACKGROUND: To perform successful coil embolization of cerebral aneurysms, it is crucial to make an appropriately shaped microcatheter tip for an aneurysm and its parent artery. So far, we manually shaped a mandrel by referencing two-dimensional (2D) images of a rotation digital subtraction angiography (DSA) on a computer screen. However, this technique requires a lot of experience, and often involves trial and error. Recently, there have been increasing reports of manual mandrel shaping using a full-scale three-dimensional (3D) model of an aneurysm and its parent artery output by various types of 3D printer. We have further developed this method by producing a hollow model of an aneurysm and its parent artery with a stereolithography 3D printer and inserting a mandrel inside the model to fit and stabilize a microcatheter tip. METHODS: Based on digital imaging and communications in medicine (DICOM) data obtained by rotational DSA, 3D images of an aneurysm and its parent artery were created and converted into standard triangulated language (STL) data. A hollow model was produced by extruding the STL data outward in the normal direction, and then a hole was made at the tip of the aneurysm using these STL data. We output these STL data to a stereolithography 3D printer. After cleaning and sterilizing the model, the mandrel was inserted in the direction of the parent artery through the hole made in the tip of the aneurysm and pushed in, creating the ideal mandrel shape. Twelve cases (14 aneurysms) were included in this study. A microcatheter tip was shaped by this method for patients who were scheduled to undergo coil embolization for an unruptured aneurysm. RESULTS: In 13 of the 14 aneurysms, the microcatheter was easily guided into the aneurysms in one or two trials, the position of the microcatheter tip in the aneurysm was appropriate, and the stability during coil embolization was high. CONCLUSION: Our method differs from the conventional one in that a hollow model made of resin is produced with a stereolithography 3D printer and that the mandrel is shaped by inserting it retrogradely into the hollow model. Using our new method, it will be possible to shape the tip of a microcatheter suitable for safe and stable coil embolization without relying on an operator's experience.

Transcondylar fossa approach for the large, high-flow, and diffuse arteriovenous malformation of the posterior fossa.

Posterior fossa high-grade arteriovenous malformations (AVMs) are challenging diseases. This video presents the treatment of a patient with a diffuse, high-flow AVM of the posterior fossa on the tonsil and cerebellopontine angle (4 cm in diameter) and deep draining veins. The patient had an intraventricular and cerebellar hemorrhage. After conservative treatment, total resection of the AVM was performed with embolization and surgery. The authors resected the nidus after the endovascular embolization, on the same day. The postoperative course was uneventful, and the patient was discharged with almost full recovery. The video can be found here: https://youtu.be/logCCn3uKUc.