Neurological misdiagnoses of lymphoma.

BACKGROUND: Lymphoma of the nervous system is rare and usually involves the brain, spinal cord, or peripheral nerves. Hence, it has varied clinical presentations, and correct diagnosis is often challenging. Incorrect diagnosis delays the appropriate treatment and affects prognosis. We report 5 patients with delayed diagnosis of lymphoma involving the central and/or peripheral nervous system, initially evaluated for other neurological diagnoses. We also discuss the challenge of diagnosis and appropriate testing. METHODS: Retrospective review of 2011-2019 records of patients with confirmed nervous system lymphoma diagnosed in a tertiary care medical center. RESULTS: We present 5 adult patients initially evaluated for inflammatory myelopathy, inflammatory lumbosacral plexopathy, atypical parkinsonism, and demyelinating disease of the CNS. Final diagnosis of the nervous system lymphoma was delayed by 4 to 18 months and was based on tissue biopsy in 4, and on CSF and bone marrow examination in 1 patient. CONCLUSIONS: Lymphoma may imitate various central and peripheral nervous system disorders. We suggest several red flags that indicate the need to consider lymphoma, including subacute but progressive symptomatic evolution, painful neurological deficit, unclear clinical diagnosis, and transient steroid responsiveness. Correct diagnosis often requires a combination of diagnostic tests, while pathology testing is crucial for early diagnosis and is strongly recommended in the appropriate clinical setting.

[SPONTANEOUS PARENCHYMAL INTRACRANIAL HEMORRHAGE - A DIAGNOSTIC CHALLENGE].

INTRODUCTION: Non-traumatic intracranial hemorrhage (ICH) is a devastating event associated with a high rate of morbidity and mortality. Patient age, hemorrhage location, number of foci, and underlying diseases are important clues to the etiology. Non-contrast head CT, given its availability and high sensitivity in detecting blood products, is frequently the first tool to readily detect ICH; however, different types of hemorrhages may share a common appearance on CT and the optimal therapeutic approach varies depending on etiology. An additional diagnostic work-up is frequently indicated to make the final diagnosis and to assist in urgent patient management. CT- and MR angiography, and digital angiography can diagnose vascular anomalies, CT venography can reveal cerebral vein thrombosis, diffusion-weighted MRI (DWI) may show hemorrhagic transformation of an infarct, and susceptibility-weighted MRI (SWI) may detect hypertensive and amyloid angiopathy-related microbleeds. MR also has a major role in revealing underlying etiologies such as cavernoma, primary brain tumor or metastases. These imaging tools assist in determining the cause of ICH, and also in assessing the risk of deterioration. Prognostic factors such as size, location, mass effect, and detection of the "spot sign" all play an important role in foreseeing possible deterioration, thus allowing prompt intervention. This study will present cases of intraparenchymal hemorrhage from different etiologies in patients who presented to the Hadassah-Hebrew University Medical Center, with the goal of illustrating the role of imaging in patient management and decision-making.

Drops in Barometric Pressure Are Associated with Deep Intracerebral Hemorrhage.

BACKGROUND AND PURPOSE: The objective of this study is to assess the effects of changes in barometric pressure and outdoor temperature on the incidence of different subtypes of intracerebral hemorrhage (ICH). METHODS: Consecutive patients with primary supratentorial ICH were included. All patients resided in the same geographic area. We compared patients with subcortical ICH to those with cortical ICH. Meteorological data were continuously accrued. High-risk ICH days were defined as those on which 1 or more patients with ICH were admitted and compared to non-high-risk days. We analyzed the relationship between spontaneous ICH location and averaged daily atmospheric pressures and temperatures. RESULTS: We included 206 patients (147 with deep ICH and 59 with lobar ICH). Patients with deep ICH were younger (P < .001), more often had histories of diabetes, smoking and previous lacunar strokes, and were more often male (P < .01 for all). Drops in mean air pressure 2 days prior to the ictus were associated with deep but not lobar ICH (P = .006). Deep ICH clustered during February months in parallel with larger changes in barometric pressures (P < .001). CONCLUSIONS: Drops in daily atmospheric pressures were associated with deep but not cortical ICH, suggesting a link to hypertensive etiology. Changes in barometric pressures were also associated with higher monthly frequencies of ICH.

Central fever in patients with spontaneous intracerebral hemorrhage: predicting factors and impact on outcome.

BACKGROUND: Central fever (CF) is defined as elevated temperature with no identifiable cause. We aimed to identify risk factors for developing CF among patients with spontaneous intracerebral hemorrhage (ICH) and to evaluate the impact of CF on outcome. METHODS: Patients included in our prospective stroke registry between 1/1/09 and 1/10/10 were studied. We identified patients with CF as those with a temperature ≥38.3°C without evidence for infection or drug fever. Patients with CF were compared to those without fever and those with infectious fever. Demographics, risk factors and imaging data as well as outcome parameters were reviewed. RESULTS: We identified 95 patients with spontaneous ICH (median age 76, median admission NIHSS 9). CF was identified in 30 patients (32%), infectious etiology was found in 9 patients (9%) and the remaining patients did not develop fever. Baseline variables were similar between the groups except for intra-ventricular extension of the ICH (IVH) and larger ICH volumes that were more common in the CF group (OR = 4.667, 95% CI 1.658-13.135 and OR = 1.013/ml, 95% CI 1.004-1.021). Outcome analysis showed higher mortality rates (80% vs. 36%, p < 0.001) and lower rates of favorable functional outcome defined as a modified Rankin score ≤ 2 at 90 days (0% vs. 53%, p < 0.001) in the CF group. CONCLUSIONS: The risk of CF is increased in patients with larger ICH and in those with IVH. CF negatively impacts outcome in patients with ICH.

Meningitis and Meningoencephalitis among Israel Defense Force Soldiers: 20 Years Experience at the Hadassah Medical Centers.

BACKGROUND: Meningitis and meningoencephalitis pose major risks of morbidity and mortality. OBJECTIVES: To describe 20 years of experience treating infections of the central nervous system in Israel Defense Force (IDF) soldiers, including the common presentations, pathogens and sequelae, and to identify risk groups among soldiers. METHODS: All soldiers who were admitted to the Hadassah University Medical Center (both campuses: Ein Kerem and Mt. Scopus) due to meningitis and meningoencephalitis from January 1993 to January 2014 were included in this retrospective study. Clinical, laboratory and radiologic data were reviewed from their hospital and army medical corps files. Attention was given to patients' military job description, i.e., combat vs. non-combat soldier, soldiers in training, and medical personnel. RESULTS: We identified 97 cases of suspected meningitis or meningoencephalitis. Six were mistakenly filed and these patients were found to have other disorders. Four soldiers were diagnosed with epidural abscess and five with meningitis due to non-infectious in flammatory diseases. Eighty-two soldiers in active and reserve duty had infectious meningitis or meningoencephalitis. Of these, 46 (56.1%) were combat soldiers and 31 (37.8%) non-combat; 20 (29.2%) were soldiers in training, 10 (12.2%) were training staff and 8 (9.8%) were medical staff. The main pathogens were enteroviruses, Epstein-Barr virus an d Neisseria meningitidis. CONCLUSIONS: In our series, soldiers in training, combat soldiers and medical personnel had meningitis and meningoencephalitis more than other soldiers. Enteroviruses are highly infectious pathogens and can cause outbreaks. N. meningitidis among IDF soldiers is still a concern. Early and aggressive treatment with steroids should be considered especially in robust meningoencephalitis cases.

Lung cancer is associated with acute ongoing cerebral ischemia: A population-based study.

BACKGROUND AND OBJECTIVES: Cerebral microinfarcts (CMIs) are the most common type of brain ischemia; however, they are extremely rare in the general population. CMIs can be detected by magnetic resonance diffusion-weighted imaging (MRI-DWI) only for a very short period of approximately 2 weeks after their formation and are associated with an increased stroke risk and cognitive impairment. We aimed to examine CMI detection rate in patients with lung cancer (LC), which is strongly associated with ischemic stroke risk relative to other cancer types. METHODS: We used the Clalit Health Services record (representing more than 5 million patients) to identify adults with LC and breast, pancreatic, or colon cancer (non-lung cancer, NLC) who underwent brain magnetic resonance diffusion (MRI) scan within 5 years following cancer diagnosis. All brain MRI scans were reviewed, and CMIs were documented, as well as cardiovascular risk factors. RESULTS: Our cohort contained a total of 2056 MRI scans of LC patients and 1598 of NLC patients. A total of 143 CMI were found in 73/2056 (3.5%) MRI scans of LC group compared to a total of 29 CMI in 22/1598 (1.4%) MRI scans of NLC (p < 0.01). Cancer type (e.g. LC vs NLC) was the only associated factor with CMI incidence on multivariate analysis. After calculating accumulated risk, we found an incidence of 2.5 CMI per year in LC patients and 0.5 in NLC. DISCUSSION: CMIs are common findings in cancer patients, especially in LC patients and therefore might serve as a marker for occult brain ischemia, cognitive decline, and cancer-related stroke (CRS) risk.

Association of Acute Incidental Cerebral Microinfarcts With Subsequent Ischemic Stroke in Patients With Cancer: A Population-Based Study.

BACKGROUND AND OBJECTIVES: Incidental diffuse-weighted imaging (DWI)-positive subcortical and cortical lesions, or acute incidental cerebral microinfarcts (CMIs), are a common type of brain ischemia, which can be detected on magnetic resonance DWI for approximately 2 weeks after occurrence. Acute incidental CMI was found to be more common in patients with cancer. Whether acute incidental CMI predicts future ischemic stroke is still unknown. We aimed to examine the association between acute incidental CMI in patients with cancer and subsequent ischemic stroke or transient ischemic attack (TIA). METHODS: This is a retrospective cohort study. We used Clalit Health Services records, representing over half of the Israeli population, to identify adults with lung, breast, pancreatic, or colon cancer who underwent brain MRI between January 2014 and April 2020. We included patients who underwent scan between 1 year before cancer diagnosis and 1 year after diagnosis. Primary outcome was ischemic stroke or TIA using International Classification of Diseases, Ninth Revision codes. Secondary outcomes were intracranial hemorrhage (ICH) and mortality. Records were followed from first MRI until primary outcome, death, or end of follow-up (January 2023). Cox proportional hazards models were used to calculate hazard ratio (HR) for patients with and without acute incidental CMI, as a time-dependent covariate. RESULTS: The study cohort included 1,618 patients with cancer, among whom, 59 (3.6%) had acute incidental CMI on at least 1 brain MRI. The median (interquartile range) time from acute incidental CMI to stroke or TIA was 26 days (14-84). On multivariable analysis, patients with acute incidental CMI had a higher stroke or TIA risk (HR 2.97, 95% CI 1.08-8.18, p = 0.035) compared with their non-CMI counterparts. Acute incidental CMIs were also associated with mortality after multivariable analysis (HR 2.76, 95% CI 2.06-3.71, p < 0.001); no association with ICH was found. DISCUSSION: Acute incidental CMI on brain MRI in patients with active cancer is associated with an increased risk of near-future ischemic stroke or TIA and mortality. This finding might suggest that randomly detected acute incidental CMI in patients with cancer may guide primary cerebrovascular risk prevention and etiologic workup.

Clinicoradiologic Criteria for the Diagnosis of Stroke-like Episodes in MELAS.

Background and Objectives: Stroke-like episodes (SLEs) in patients with mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome are often misdiagnosed as acute ischemic stroke (AIS). We aimed to determine unique clinical and neuroimaging features for SLEs and formulate diagnostic criteria. Methods: We retrospectively identified patients with MELAS admitted for SLEs between January 2012 and December 2021. Clinical features and imaging findings were compared with a cohort of patients who presented with AIS and similar lesion topography. A set of criteria was formulated and then tested by a blinded rater to evaluate diagnostic performance. Results: Eleven MELAS patients with 17 SLE and 21 AISs were included. Patients with SLEs were younger (median 45 [37-60] vs 77 [68-82] years, p < 0.01) and had a lower body mass index (18 ± 2.6 vs 29 ± 4, p < 0.01), more commonly reported hearing loss (91% vs 5%, p < 0.01), and more commonly presented with headache and/or seizures (41% vs 0%, p < 0.01). The earliest neuroimaging test performed at presentation was uniformly a noncontrast CT. Two main patterns of lesion topography with a stereotypical spatiotemporal evolution were identified-an anterior pattern (7/21, 41%) starting at the temporal operculum and spreading to the peripheral frontal cortex and a posterior pattern (10/21, 59%) starting at the cuneus/precuneus and spreading to the lateral occipital and parietal cortex. Other distinguishing features for SLEs vs AIS were cerebellar atrophy (91% vs 19%, p < 0.01), previous cortical lesions with typical SLE distribution (46% vs 9%, p = 0.03), acute lesion tissue hyperemia and venous engorgement on CT angiography (CTA) (45% vs 0%, p < 0.01), and no large vessel occlusion on CTA (0% vs 100%, p < 0.01). Based on these clinicoradiologic features, a set of diagnostic criteria were constructed for possible SLE (sensitivity 100%, specificity 81%, AUC 0.905) and probable SLE (sensitivity 88%, specificity 95%, AUC 0.917). Discussion: Clinicoradiologic criteria based on simple anamnesis and a CT scan at presentation can accurately diagnose SLE and lead to early administration of appropriate therapy. Classification of Evidence: This study provides Class III evidence that an algorithm using clinical and imaging features can differentiate stroke-like episodes due to MELAS from acute ischemic strokes.

Between a rock and a hard place: clinical and imaging features of vascular compression syndromes.

Vascular compression syndromes are caused by the entrapment of vessels between rigid or semirigid surfaces in a confined anatomic space. Chronic entrapment may lead to arterial ischemia and embolism, venous stasis and thrombosis, and hematuria. These syndromes are usually seen in otherwise healthy young patients, among whom underdiagnosis is common. Most occurrences of vascular compression are associated with an underlying anatomic abnormality. In a small percentage of cases, other contributing factors, including repetitive microtrauma, may cause pathologic changes leading to the onset of pain and other symptoms of vascular and neural compression. Hence, the diagnosis must be based on both clinical and radiologic findings. Because some cases of vascular entrapment become symptomatic only when specific physical maneuvers are performed, dynamic diagnostic imaging methods are especially useful. Digital subtraction angiography has been the mainstay of imaging-based diagnosis for most vascular compression syndromes, but other methods (eg, color Doppler ultrasonography, computed tomographic angiography, and magnetic resonance angiography) are used with increasing frequency for initial diagnostic evaluation. Because vascular compression syndromes are caused by the external compression of vessels, endoluminal treatment alone is rarely adequate and surgical decompression is likely to be required for optimal and durable clinical benefit. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.321115011/-/DC1.

Characterization of Meningitis and Meningoencephalitis in the Israeli Defense Forces From 2004 to 2015: A Population-Based Study.

Background: Meningitis and meningoencephalitis (MME) are potential medical emergencies. Mandatory reporting of all MME cases in the Israel Defense Force (IDF) allows accurate characterization of MME incidence and course. In the present study, we described the epidemiology of MME in soldiers. Methods: Medical charts of 860,000 combat and non-combat soldiers serving during the years 2004-2015, accounting for 2,256,060 patient years, were retrospectively evaluated. The diagnosis of MME was based on signs of meningeal irritation and a count of > 5 white blood cells (WBC) in the cerebrospinal fluid (CSF). Data on the diagnosis of bacterial or aseptic MME, significant sequelae, and associated mortality were collected. Results: Approximately 273 cases of MME were diagnosed. Overall, MME incidence was 12.1/100,000 patient-years. Bacterial and viral pathogens were identified in 31/273 (11.4%) and 52/273 (19%) cases, respectively. Combat soldiers had higher incidence of bacterial meningitis [14/40 (35%) vs. 31/212 (14.6%); p = 0.002] and meningoencephalitis [13/40 (32.5%) vs. 33/212 (15.6%); p = 0.023] compared to non-combat soldiers. Their clinical presentation was more severe, including confusion [10/40 (25%) vs. 22/212 (10.4%); p = 0.018], focal neurological deficits [12/40 (30%) vs. 11/212 (5.2%); p < 0.0001], and status epilepticus [3/40 (7.5%) vs. 0/212 (0.0%); p < 0.01]. Mortality among combat soldiers was higher [5/40 (15%) vs. 1/212 (0.5%); p < 0.001]. N. meningitidis was the most frequently isolated bacteria, despite universal preventative vaccination. Conclusion: The incidence of bacterial MME in the IDF is higher than in the civilian population. Combat soldiers present with higher incidence of meningoencephalitis and bacterial meningitis.

Mild Phenotype of Wolfram Syndrome Associated With a Common Pathogenic Variant Is Predicted by a Structural Model of Wolframin.

OBJECTIVE: To describe the WFS1 c.1672C>T; p.R558C missense variant, found in 1.34% of Ashkenazi Jews, that has a relatively mild phenotype and to use computational normal mode analysis (NMA) to explain the genotype-phenotype relationship. METHODS: The clinical, laboratory, and genetic features of 8 homozygotes were collected. A model of the wolframin protein was constructed, and NMA was used to simulate the effect of the variant on protein thermodynamics. RESULTS: Mean age at Wolfram syndrome (WS) diagnosis among homozygotes was 30 years; diabetes (7/8) was diagnosed at mean age 19 years (15-21 years), and bilateral optic atrophy (with MRI evidence of optic/chiasm atrophy) (6/8) at mean age 29 years (15-48 years). The oldest patient (62 years) also had gait difficulties, memory problems, parietal and cerebellar atrophy, and white matter hyperintense lesions. All retained functional vision with independent ambulation and self-care; none had diabetes insipidus or hearing loss. The p.R558C variant caused less impairment of protein entropy than WFS1 variants associated with a more severe phenotype. CONCLUSIONS: The p.R558C variant causes a milder, late-onset phenotype of WS. We report a structural model of wolframin protein based on empirical functional studies and use NMA modeling to show a genotype-phenotype correlation across all homozygotes. Clinicians should be alert to this condition in patients with juvenile diabetes and patients of any age with a combination of diabetes and optic atrophy. Computational NMA has potential benefit for prediction of the genotype-phenotype relationship.

Determination of renal stone composition with dual-energy CT: in vivo analysis and comparison with x-ray diffraction.

PURPOSE: To preoperatively assess the composition of urinary stones by using dual-energy computed tomography (CT), with postoperative in vitro x-ray diffraction analysis as the reference standard. MATERIALS AND METHODS: Institutional review board approval was obtained, and all participants provided written informed consent. Twenty-seven patients aged 50-64 years with renal stones, who were scheduled for stone extraction with percutaneous nephrolithotomy (PCNL), preoperatively underwent nonenhanced single-source dual-energy multidetector CT with 2-mm section thickness, 1-mm increments, 140 kVp, and 250 mAs. Regions of interest were drawn on low- and high-energy images, and low- and high-energy attenuation ratios were calculated for each stone scanned in vivo. The attenuation ratios for the patients were compared with those for an in vitro stone library phantom model of 37 stones with known chemical compositions. After surgery, the extracted stones were analyzed by using x-ray diffraction. The results of in vivo multidetector CT and ex vivo chemical analysis were compared. RESULTS: Dual-energy low- and high-energy attenuation ratios measured with the phantom were less than 1.1 for uric acid, 1.1-1.24 for cystine, and greater than 1.24 for calcified stones. Struvite stones had attenuation ratios that overlapped with calcified stone ratios and thus could not be assessed reliably. Four patients had mixed stones (<75% of a single component), and one patient had a struvite stone. Of 27 patients, 22 (82%) (exact confidence interval [CI]: 68%, 92%) received a correct diagnosis with dual-energy CT: all six (100%; exact CI: 54%, 100%) patients with uric acid stones, 15 (79%; exact CI: 62%, 95%) of the 19 patients with calcium stones, and the one (100%) patient with a cystine stone. The patient with a struvite stone did not receive a correct dual-energy CT-based diagnosis. CONCLUSION: Dual-energy multidetector CT may enable accurate in vivo characterization of kidney stone composition.

Determination of renal stone composition with dual-energy computed tomography: an emerging application.

Urinary tract stone disease is common in the Western world. Nonenhanced computed tomography (CT) is the method of choice for stone diagnosis; however, it has a limited role in predicting stone type. Knowledge of stone composition is currently determined by postoperative assessment of stone fragments. A noninvasive tool for accurate characterization of stone composition would improve patient management. Dual-energy CT aids in the differentiation among calcium, uric acid, and cystine stones. In this review we describe the role of dual-energy CT for in vitro and in vivo analysis of urinary stones. We illustrate the technique, review the literature, and discuss future directions.

Dual-energy based spectral electronic cleansing in non-cathartic computed tomography colonography: an emerging novel technique.

Computed tomography colonography (CTC) with reduced or without bowel catharsis and with fecal tagging has emerged to improve CTC tolerability in patients and their subsequent compliance with colorectal cancer screening. With fecal tagging, electronic cleansing is performed by postprocessing software that removes remnants of contrast material. However, because the technique is threshold based, artifacts that lower the image quality and accuracy of the examination may be noted. Spectral electronic cleansing, based on dual-energy CT and on material-specific cleansing, decreases the number of artifacts and improves image quality. In this review we describe spectral cleansing with reduced catharsis CTC and illustrate its potential benefits.

Magnetic resonance-guided interventional procedures of the breast: initial experience.

BACKGROUND: Magnetic resonance imaging of the breast has emerged as a valuable imaging tool in addition to conventional imaging modalities. It has high sensitivity for malignant lesions and can detect mammographically, sonographically and clinically occult cancers. "MR only" lesions are best biopsied under MR guidance; however, this may be a challenging task. OBJECTIVES: To evaluate our initial clinical experience with MR-guided core needle breast biopsy and MR-guided needle localization. METHODS: We retrospectively evaluated 81 women with 97 lesions, who were scheduled for guided core needle biopsy or MR-guided needle localization followed by surgery. Lesions were categorized as malignant, high risk, or benign according to the BI-RADS MR classification system. MR findings were compared with final histopathology or with follow-up imaging findings. RESULTS: Fifteen (16%) lesions were malignant (9 invasive ductal carcinoma, 2 invasive lobular carcinoma, 4 ductal carcinoma in situ); 7 (7%) lesions were high risk (4 atypical ductal hyperplasia, 3 radial scars); 75 (77%) lesions were benign, mainly fibrocystic changes. Other benign findings were sclerosing adenosis, pseudoangiomatous stromal hyperplasia, fat necrosis, intraductal papilloma, fibroadenoma, capillary hemangioma, and florid ductal hyperplasia. No major complications were encountered. CONCLUSIONS: MR-guided interventional procedures of the breast are accurate, safe and feasible methods for sampling breast lesions detected only by MR and have become a significant tool in the management of certain patients.

Diffusion weighted magnetic resonance imaging of pre and post treatment nasopharyngeal carcinoma.

OBJECTIVES: To evaluate the utility of different Apparent Diffusion Coefficient (ADC) values on Diffused Weighted Magnetic Resonance Imaging (DW-MRI) for nasopharyngeal carcinoma (NPC). STUDY DESIGN AND SETTING: A retrospective cohort study in a single tertiary medical center. SUBJECTS AND METHODS: The study group consists of patients with pathology proven NPC that underwent DW-MRI prior or/and following a non-surgical chemo radiation treatment between the years 2007 and 2017. ADC thresholds were analyzed and compared for primary (pre-treatment) and expected post-irradiation NPC cases and healthy controls. RESULTS: We recruited 144 patients who underwent 195 MRI's for NPC. 25 DW-MRI were performed before (primary, active NPC) and 56 following (no residual NPC) treatment. 45 out of 225 patients who had brain DW-MRI for other reasons (control group) had measurable nasopharynx tissue (N = 33, adjusted for age and gender). The mean ADC of NPC prior to treatment (0.69 ±â€¯0.13 × 10-3 mm2/s) was significantly lower (ANOVA, P < 0.001) compared to the mean ADC of the adjusted controls (1.11 ±â€¯0.25 × 10-3 mm2/s) and post-treatment (1.49 ±â€¯0.28 × 10-3 mm2/s) groups. An ADC threshold of 0.805 × 10-3 mm2/s had 94% and 93.9% sensitivity and specificity rates, respectively and an odds ratio of 175[95%CI(23.25-1000)], comparing ADC levels of pre-treatment NPC patients and adjusted control group. An ADC threshold of 0.965 × 10-3 mm2/s yielded 100% positive and negative predicted values distinguishing pre-treatment and post-treatment NPC patients (free of disease). There was no statistical association between ADC levels and tumor volume/stage, nodal stage or group staging. CONCLUSIONS: ADC levels have distinct values in newly diagnosed and follow up of NPC.

Microelectrode Recordings Validate the Clinical Visualization of Subthalamic-Nucleus Based on 7T Magnetic Resonance Imaging and Machine Learning for Deep Brain Stimulation Surgery.

BACKGROUND: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a proven and effective therapy for the management of the motor symptoms of Parkinson's disease (PD). While accurate positioning of the stimulating electrode is critical for success of this therapy, precise identification of the STN based on imaging can be challenging. We developed a method to accurately visualize the STN on a standard clinical magnetic resonance imaging (MRI). The method incorporates a database of 7-Tesla (T) MRIs of PD patients together with machine-learning methods (hereafter 7 T-ML). OBJECTIVE: To validate the clinical application accuracy of the 7 T-ML method by comparing it with identification of the STN based on intraoperative microelectrode recordings. METHODS: Sixteen PD patients who underwent microelectrode-recordings guided STN DBS were included in this study (30 implanted leads and electrode trajectories). The length of the STN along the electrode trajectory and the position of its contacts to dorsal, inside, or ventral to the STN were compared using microelectrode-recordings and the 7 T-ML method computed based on the patient's clinical 3T MRI. RESULTS: All 30 electrode trajectories that intersected the STN based on microelectrode-recordings, also intersected it when visualized with the 7 T-ML method. STN trajectory average length was 6.2 ± 0.7 mm based on microelectrode recordings and 5.8 ± 0.9 mm for the 7 T-ML method. We observed a 93% agreement regarding contact location between the microelectrode-recordings and the 7 T-ML method. CONCLUSION: The 7 T-ML method is highly consistent with microelectrode-recordings data. This method provides a reliable and accurate patient-specific prediction for targeting the STN.

Critical analysis of the performance of double-contrast barium enema for detecting colorectal polyps > or = 6 mm in the era of CT colonography.

OBJECTIVE: The purpose of our study was to perform a meta-analysis comparing the performance of double-contrast barium enema (DCBE) with CT colonography (CTC) for the detection of colorectal polyps > or = 6 mm using endoscopy as the gold standard. MATERIALS AND METHODS: Prospective DCBE and CTC studies were identified. Percentages of polyps and of patients with polyps > or = 10 mm and 6-9 mm were abstracted. The performance of DCBE versus CTC was determined by separately evaluating each technique's performance versus that of endoscopy, and contrasting the techniques. The I-squared statistic and Fisher's exact test were used for heterogeneity, the Cochran-Mantel-Haenszel and the Kruskal-Wallis tests for correlation, and the A(z) test for comparing pooled weighted estimates of performance. RESULTS: Eleven studies of DCBE (5,995 patients, 1,548 polyps) and 30 studies of CTC (6,573 patients, 2,348 polyps) fulfilled inclusion criteria. For polyps > or = 10 mm, a 0.121-per-patient sensitivity difference favored CTC (p < 0.0001; DCBE, 0.702 [95% CI, 0.687-0.715]; CTC, 0.823 [0.809-0.836]). For polyps > or = 10 mm, a 0.031-per-polyp sensitivity difference favored CTC (p < 0.0001; DCBE, 0.715 [0.703-0.726]; CTC, 0.746 [0.735-0.757]). For polyps > or = 10 mm, a specificity difference of 0.104 favored CTC (p = 0.001; DCBE, 0.850 [0.847-0.855]; CTC, 0.954 [0.952-0.955]). DCBE was also significantly less sensitive for 6- to 9-mm polyps (p < 0.001). CONCLUSION: DCBE has statistically lower sensitivity and specificity than CTC for detecting colorectal polyps > or = 6 mm.

Computer-based radiological longitudinal evaluation of meningiomas following stereotactic radiosurgery.

PURPOSE: Stereotactic radiosurgery (SRS) is a common treatment for intracranial meningiomas. SRS is planned on a pre-therapy gadolinium-enhanced T1-weighted MRI scan (Gd-T1w MRI) in which the meningioma contours have been delineated. Post-SRS therapy serial Gd-T1w MRI scans are then acquired for longitudinal treatment evaluation. Accurate tumor volume change quantification is required for treatment efficacy evaluation and for treatment continuation. METHOD: We present a new algorithm for the automatic segmentation and volumetric assessment of meningioma in post-therapy Gd-T1w MRI scans. The inputs are the pre- and post-therapy Gd-T1w MRI scans and the meningioma delineation in the pre-therapy scan. The output is the meningioma delineations and volumes in the post-therapy scan. The algorithm uses the pre-therapy scan and its meningioma delineation to initialize an extended Chan-Vese active contour method and as a strong patient-specific intensity and shape prior for the post-therapy scan meningioma segmentation. The algorithm is automatic, obviates the need for independent tumor localization and segmentation initialization, and incorporates the same tumor delineation criteria in both the pre- and post-therapy scans. RESULTS: Our experimental results on retrospective pre- and post-therapy scans with a total of 32 meningiomas with volume ranges 0.4-26.5 cm[Formula: see text] yield a Dice coefficient of [Formula: see text]% with respect to ground-truth delineations in post-therapy scans created by two clinicians. These results indicate a high correspondence to the ground-truth delineations. CONCLUSION: Our algorithm yields more reliable and accurate tumor volume change measurements than other stand-alone segmentation methods. It may be a useful tool for quantitative meningioma prognosis evaluation after SRS.