MRI Diffusion-Weighted Imaging to Measure Infarct Volume: Assessment of Manual Segmentation Variability.

BACKGROUND AND PURPOSE: Manual segmentation of infarct volume on follow-up MRI diffusion-weighted imaging (MRI-DWI) is considered the gold standard but is prone to rater variability. We assess the variability of manual segmentations of MRI-DWI infarct volume. METHODS: Consecutive patients (May 2018 to May 2019) with the anterior circulation stroke and endovascularly treated were enrolled. All patients underwent 24- to 32-hour follow-up MRI. Three users manually segmented DWI infarct volumes slice by slice twice. The reference standard of DWI infarct volume was generated by the STAPLE algorithm. Intra- and interrater reliability was evaluated using the intraclass correlation coefficient (ICC) by comparing manual segmentations with the reference standard. Spatial measurements were evaluated using metrics of the Dice similarity coefficient (DSC). Volumetric measurements were compared using the lesion volume. RESULTS: The dataset consisted of 44 patients, mean (SD) age was 70.1 years (±10.3), 43% were women, and median baseline NIHSS score was 16. Among three users, the mean DSC for MRI-DWI infarct volume segmentations ranged from 80.6% ± 11.7% to 88.6% ± 7.5%, and the mean absolute volume difference was 2.8 ± 6.8 to 13.0 ± 14.0 ml. Interrater ICC among the users for DSC and infarct volume was .86 (95% confidence interval [95% CI]: .78-.91) and .997 (95% CI: .995-.998). Intrarater ICC for the three users was .83 (95% CI: .69-.93), .84 (95% CI: .72-.91), and .80 (95% CI: .64-.89) for DSC, and .99 (95% CI: .987-.996), .991 (95% CI: .983-.995), and .996 (95% CI: .993-.998) for infarct volume. CONCLUSIONS: Manual segmentation of infarct volume on follow-up MRI-DWI shows excellent agreement and good spatial overlap with the reference standard, suggesting its usefulness for measuring infarct volume on 24- to 32-hour MRI-DWI.

Factors influencing therapy choice and clinical outcome in cerebral venous sinus thrombosis.

We aimed was to assess the factors influencing therapy choice and clinical outcome after 3-4 months in patients with cerebral venous sinus thrombosis (CVST). In a retrospective, bi-centric study, the set consisted of 82 consecutive CVST patients (61 females; mean age 33.5 ± 15.7 years). Following data were collected: baseline characteristics, presence of gender-specific risk factors (GSRF), location and extent of venous sinus impairment, clinical presentation, type of treatment, recanalization, presence of parenchymal lesions, and clinical outcome after 3-4 months (assessed using the modified Rankin Scale [mRS], with excellent outcome defined as mRS 0-1). Multivariate logistic regression analysis was used for statistical evaluation. After 3-4 months, complete recovery was achieved in 41 (50%) and excellent clinical outcome in 67 (81.7%) patients. Female sex (OR 0.11; p = 0.0189) and presence of focal neurologic deficit (OR 0.16; p = 0.0165) were identified as significant independent negative predictors and, the presence of GSRF (OR 15.63; p = 0.0011) as significant independent positive predictor of excellent clinical outcome. In conclusion, in our CVST patients, the presence of GSRF was associated with excellent clinical outcome, while the female sex itself was associated with poorer clinical outcome.

Machine learning volumetry of ischemic brain lesions on CT after thrombectomy-prospective diagnostic accuracy study in ischemic stroke patients.

PURPOSE: Ischemic lesion volume (ILV) is an important radiological predictor of functional outcome in patients with anterior circulation stroke. Our aim was to assess the agreement between automated ILV measurements on NCCT using the Brainomix software and manual ILV measurements on diffusion-weighted imaging (DWI). METHODS: This was a prospective single-center observational study of patients with CT angiography (CTA) proven anterior circulation occlusion treated with endovascular thrombectomy (May 2018 to May 2019). NCCT ILV was measured automatically by the Brainomix software. DWI ILV was measured manually. The McNemar's test was used to test sensitivity and specificity. The Somer's delta was used to test the differences between concordant and discordant ASPECTS regions. The Bland-Altman plot was calculated to compare the differences between Brainomix and DWI ILVs. RESULTS: Forty-five patients were included. Median Brainomix ILV was 23 ml (interquartile range [IQR], 15-39 ml), and median DWI ILV was 11.5 ml (IQR, 7-32 ml) in the TICI 2b-3 group. In the TICI 0-2a, the NCCT ILV was 39 ml (IQR, 18-62 ml) and DWI ILV was 30 (IQR, 11-105 ml). The DWI ILVs in patients with good clinical outcome (mRS 0-2) was significantly lower compared with patients with mRS ≥ 3 (10 mL vs 59 mL, p = 0.002). Similar trend was observed for Brainomix ILV measurements (21 mL vs 39 mL, p = 0.012). There was a high correlation and accuracy in the detection of follow-up ischemic changes in particular ASPECTS regions. CONCLUSION: NCCT ILV measured automatically by the Brainomix software might be considered a valuable radiological outcome measure.

Evaluation of spine structure stability at different locations during SBRT.

BACKGROUND AND AIMS: Modern stereotactic body radiotherapy (SBRT) techniques and systems that use online image guidance offer frameless radiotherapy of spinal tumors and the ability to control intrafraction motion during treatment. These systems allow precise alignment of the patient during the entire treatment session and react immediately to random changes in this alignment. Online tracking data provide information about intrafractional changes, and this information can be useful for designing treatment strategies even if online tracking is not being used. The present study evaluated spine motion during SBRT treatment to assess the risk of verifying patient alignment only prior to starting treatment. METHODS: This study included 123 patients treated with spine SBRT. We analyzed different locations within the spine using system log files generated during treatment, which contain information about differences in the pretreatment reference spine positions by CT versus positions during SBRT treatment. The mean spine motion and intra/interfraction motion was evaluated. We defined and assessed the spine stability and spine significant shifts (SSHs) during treatment. RESULTS: We analyzed 462 fractions. For the cervical (C) spine, the greatest shifts were in the anterior-posterior (AP) direction (2.48 mm) and in pitch rotation (1.75 deg). The thoracic (Th) spine showed the biggest shift in the AP direction (3.68 mm) and in roll rotation (1.66 deg). For the lumbar-sacral (LS) spine, the biggest shift was found for left-right (LR) translation (3.81 mm) and roll rotation (3.67 deg). No C spine case exceeded 1 mm/1 deg for interfraction variability, but 7 of 54 Th spine cases exceeded 1 mm interfraction variability for translations (maximum value, 2.5 mm in the AP direction). The interfraction variability for translations exceeded 1 mm in 2 of 24 LS spine cases (maximum value, 1.7 mm in the LR direction). Only 13% of cases had no SSHs. The mean times to SSH were 6.5±3.9 min, 8.1±5.9 min, and 8.8±7.1 min for the C, Th, and LS spine, respectively, and the mean recorded SSH values were 1.6±0.66, 1.43±0.33, and 1.46±0.47 mm/deg, respectively. CONCLUSION: Positional tracking during spine SBRT treatments revealed low mean translational and rotational shifts. Patient immobilization did not improve spine shifts compared with our results for the Th and LS spine without immobilization. For the most precise spine SBRT, we recommend checking the patient's position during treatment.

Anesthesia type determines risk of cerebral infarction after carotid endarterectomy.

OBJECTIVE: Silent and symptomatic cerebral infarctions occur in up to 34% of patients after carotid endarterectomy (CEA). This prospective study compared the risk of new brain infarctions detected by magnetic resonance imaging (MRI) in patients with internal carotid artery stenosis undergoing CEA with local anesthesia (LA) vs general anesthesia (GA). METHODS: Consecutive patients with internal carotid artery stenosis indicated for CEA were screened at two centers. Patients without contraindication to LA or GA were randomly allocated to the LA or GA group by ZIP code randomization. Brain MRI was performed before and 24 hours after CEA. Neurologic examination was performed before and 24 hours and 30 days after surgery. The occurrence of new infarctions on the control magnetic resonance images, stroke, transient ischemic attack, and other complications was statistically evaluated. RESULTS: Of 210 randomized patients, 105 underwent CEA with LA (67 men; mean age, 68.3 ± 8.1 years) and 105 with GA (70 men; mean age, 63.4 ± 7.5 years). New infarctions were more frequently detected on control magnetic resonance images in patients after CEA under GA compared with LA (17.1% vs 6.7%; P = .031). Stroke or transient ischemic attack occurred within 30 days of CEA in three patients under GA and in two under LA (P = 1.000). There were no significant differences between the two types of anesthesia in terms of the occurrence of other complications (14.3% for GA and 21.0% for LA; P = .277). CONCLUSIONS: The risk of silent brain infarction after CEA as detected by MRI is higher under GA than under LA.

Diffusion-weighted magnetic resonance imaging is more sensitive than dimercaptosuccinic acid scintigraphy in detecting parenchymal lesions in children with acute pyelonephritis: A prospective study.

INTRODUCTION: Static renal scintigraphy is the gold standard for detection of inflammatory changes in the renal parenchyma in acute pyelonephritis. Our aim was to determine whether diffusion-weighted magnetic resonance imaging (DW-MRI) was comparable with static renal scintigraphy (DMSA-SRS) to demonstrate acute renal parenchymal lesions. OBJECTIVE: To compare 99mTc-dimercaptosuccinic acid static renal scintigraphy (DMSA-SRS) with diffusion-weighted magnetic resonance imaging (DW-MRI) for detecting acute inflammatory changes in the renal parenchyma in children with febrile urinary tract infection. METHODS: Thirty-one children (30 girls) aged 3-18 years with a first episode of febrile UTI without a previously detected congenital malformation of the urinary tract, were prospectively included. DMSA-SRS and DW-MRI were performed within 5 days of diagnosis to detect renal inflammatory lesions. The DW-MRI examination was performed without contrast agent and without general anesthesia. Late examinations were performed after 6 months using both methods to detect late lesions. RESULTS: DW-MRI confirmed acute inflammatory changes of the renal parenchyma in all 31 patients (100%), mostly unilateral. DMSA-SRS detected inflammatory lesions in 22 children (71%; p = 0.002). The lesions were multiple in 26/31 children (84%) on DW-MRI and in 9/22 (40%) on DMSA-SRS. At the control examination, scarring of the renal parenchyma was found equally by DW-MRI and DMSA-SRS in five patients (16%), three of whom were the same patients. The overall concordance of positive and negative late findings occurred in 87% of patients. There was correspondence in the anatomical location of acute and late lesions. DISCUSSION: The clinical significance of acute and late parenchymal findings on DWI-MR is yet to be determined. A limitation of our study is the age of the patients (older than 3 years) who are less sensitive to scar development; therefore, a smaller number of patients with scars could be analyzed during control examination. Further studies using the DW-MRI should confirm its reliability to detect acute and late lesions in younger children and infants and determine the clinical consequences. CONCLUSION: DW-MRI has higher sensitivity for detecting acute renal inflammatory lesions and multifocal lesions than DMSA-SRS. The incidence of scars was low and corresponded with the anatomical location of acute and late lesions.

[The rational diagnostic of cholangiocarcinoma]. / Racionální diagnostika cholangiokarcinomu.

Cholangiocarcinoma (CC) is a rare malignant tumour arising from cholangiocytes, and its prognosis is usually unfavourable, mostly as a result of late diagnosis of the tumour. The current incidence of cholangiocarcinoma in the Czech Republic is 1.4/100,000 inhabitants per year; in less than 30 % of patients with CC, one of the known risk factors can be identified, most frequently, primary sclerosing cholangitis. Only patients with early diagnosed and surgically amenable cholangiocarcinoma are likely to have a longer survival time; in their case, survival for more than five years has been achieved in 20 % to 40 %. From the perspective of the need for early diagnosis of CC, a significant part is played by imaging and histopathologic evaluation; the early diagnostic significance of oncomarkers is limited. The rational early diagnosis of CC consists in effective use of differentiated advantages of different imaging modalities - MRI with DSA appears to be the optimal method, endosonography is a sensitive method for the identification of malignancy in the hepatic hilum or distal common bile duct, MRCP (magnetic resonance cholangiopancreatography) is used to display pathological changes in the biliary tree, ERCP (endoscopic retrograde cholangiopancreatography) allows material removal for histopathological examination. Other new approaches are also beneficial, such as IDUS - intraductal ultrasonography of biliary tract or SPY-GLASS, enabling examination of the bile ducts by direct view with the possibility of taking targeted biopsies. Sensitivity and specificity of histology and cytology can be increased by using the molecular cytogenetic FISH method, i.e. fluorescence in situ by hybridization, with a specificity of 97 %.

[Rare case of cystic disease of the liver - alveolar echinococcosis of the liver]. / Neobvyklý prípad cystického postizení jater - alveolární echinokokóza jater.

Alveolar echinococcosis is a rare parasitic disease, especially of liver, caused by larval stage of tapeworm Echinococcus multilocularis. At the end of the last century France, Germany, Austria and Switzerland were the most often regions with this disease, these days is this infection diagnosed also in our territory. We describe the case of the disease of the twenty-five years old male with nonspecific signs and hepatomegaly, who was diagnosed on the basis of imaging and laboratory sampling. Due to inoperability the patient is now in infectologist follow-up on a long-term treatment with albendazole. He is clinically stable, included in waiting list for liver transplantation.Key words: alveolar echinococcosis - benzimidazols - Echinococcus multilocularis - parasitic disease of liver.

Comparison of brain vessel imaging from transtemporal and transcondylar approaches using contrast-enhanced transcranial color-coded duplex sonography and Virtual Navigator.

AIMS: The transcondylar approach is a new and used for detection of chronic cerebro-spinal venous insufficiency (CCSVI) and intracranial venous reflux in patients with multiple sclerosis. The aim of this study was to assess the ability of native and contrast enhanced (CE-) transcranial color-coded duplex sonography (TCCS) to detect flow and reflux in deep cerebral veins and intracranial venous sinuses from transcondylar and transtemporal approaches. METHODS: Brain magnetic resonance imaging and TCCS from transtemporal and transcondylar approaches using the new technology - Fusion Imaging - in 8 volunteers and 5 patients with multiple sclerosis. RESULTS: Using TCCS and CE-TCCS, the arteries of the circle of Willis could be detected from the transtemporal approach in 13/13 subjects in both examinations, while detection of the venous system was possible in 7/13 and 9/13 subjects, respectively. However, the arteries of the circle of Willis and venous system were detected through the transcondylar approach in only 5/13 (P=0.041) and 1/13 (P=0.031) subjects using TCCS, and in 12/13 (P=0.921) and 7/13 (P=0.687) subjects using CE-TCCS, respectively. CONCLUSIONS: The results reveal that the TCCS transcondylar approach has serious limitations for the standard detection of intracranial venous reflux.