Hemosiderin Detection inside the Mammillary Bodies Using Quantitative Susceptibility Mapping on Patients with Wernicke-Korsakoff Syndrome

Hemorrhage inside the mammillary bodies (MMBs) is known to be one of the findings of Wernicke encephalopathy. Brain MRI of two patients with Wernicke-Korsakoff syndrome (WKS) demonstrated high susceptibility values representing hemosiderin deposition in MMBs by using quantitative susceptibility mapping (QSM). QSM provided additional information of susceptibility values to susceptibility-weighted imaging in diagnosis of WKS.

Sclerosing Angiomatoid Nodular Transformation of the Spleen: Radiological Findings and Radiological-pathological Correlation

Introduction

The objective of this study was to describe the CT and MRI features of sclerosing angiomatoid nodular transformation (SANT) of the spleen with pathologic correlation.

Materials and Methods

Ten patients with surgically resected and pathologically confirmed SANTs were included. Clinical history was reviewed, and gross pathologic, histologic, and immunohistochemical findings were recorded. CT and MRI examinations were evaluated by two radiologists.

Results

Patients included seven men and three women, with a mean age of 42.9±16.7 years. Pathologic features of SANTs involved multiple angiomatous nodules in a radiating pattern with a central stellate fibrous scar and evidence of hemosiderin deposition. 9 cases showed a lobulated demarcated margin, 8 cases a slight hypoattenuating, 1 isoattenuating, and 1 case with two lesions demonstrated a slight hyperattenuating margin, respectively. Multiple scattered punctate calcifications were involved in 2 cases. 5 cases manifested hypointensity on in-phase imaging, 1 iso-intensity, and 4 iso-hypointensity on out-of-phase imaging. Progressive and centripetal enhancement were exhibited in 10 cases, spoke-wheel pattern in 3 cases, and nodular enhancement in 4 cases, respectively. The central fibrous scar was identified in 8 cases during delayed enhancement.

Conclusion

Characteristics of SANTs on CT/MRI reflected the underlying pathology. Hypointensity on DWI and T2WI, and change of signal on T1 chemicalshift imaging were found to be due to hemosiderin deposition and fibrous tissue. Typical feature was a solitary, round, lobulated mass with a fibrous scar. Progressive and centripetal enhancement, spoke-wheel pattern, nodular enhancement, and delayed enhancement of central fibrous scar were observed.

Assessment of Imaging Findings of Renal Carcinoma Subtypes with 3.0T MRI

BACKGROUND

The prevalence of renal masses has escalated as a result of the augmented utilization of cross-sectional imaging techniques. The approach to managing renal masses may exhibit variability contingent upon the subtype of renal cell carcinoma (RCC).

AIM

This research aimed to distinguish between clear cell and papillary RCCs, utilizing dynamic contrast magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI).

MATERIALS AND METHODS

The study assessed the MR images of 112 patients with RCC. Two radiologists independently analyzed tumor size, vascular involvement, signal characteristics in T1- and T2-weighted sequences, the presence of hemosiderin, both microscopic and macroscopic fat content, enhancement patterns, and apparent diffusion coefficient (ADC) values derived from b-values of 1000 s/mm².

RESULTS

Seventy patients had clear cell RCC, and 42 had papillary. In the clear cell RCC, microscopic fat content was significantly higher than the papillary RCC (P < 0.001). However, in papillary RCC, hemosiderin content was substantially greater (P = 0.001). On T2-weighted MR images, clear cell RCCs were usually hyperintense, while papillary RCCs were hypointense (P < 0.001). Even though the rapid enhancement pattern was observed in clear cell RCCs, the progressive enhancement pattern was more prevalent in papillary RCCs (P < 0.001).

CONCLUSION

Hyperintensity on T2-weighted images, microscopic fat content, and rapid enhancement pattern may be indicative of clear cell RCC, whereas hypointensity on T2-weighted images, hemosiderin content, and a progressive contrast pattern may be diagnostic for papillary RCC.

Comparison of four different displays for identification of select pathologic features extracted from whole slide images of surgical pathology cases

BACKGROUND

The establishment of minimum standards for display selection for the whole slide image (WSI) interpretation has not been fully defined. Recently, pathologists have increasingly preferred using remote displays for clinical diagnostics. Our study aims to assess and compare the performance of three fixed work displays and one remote personal display in accurately identifying ten selected pathologic features integrated into WSIs.

DESIGN

Hematoxylin and eosin-stained glass slides were digitized using Philips scanners. Seven practicing pathologists and three residents reviewed ninety WSIs to identify ten pathologic features using the LG, Dell, and Samsung and an optional consumer-grade display. Ten pathologic features included eosinophils, neutrophils, plasma cells, granulomas, necrosis, mucin, hemosiderin, crystals, nucleoli, and mitoses.

RESULTS

The accuracy of the identification of ten features on different types of displays did not significantly differ among the three types of "fixed" workplace displays. The highest accuracy was observed for the identification of neutrophils, eosinophils, plasma cells, granuloma, and mucin. On the other hand, a lower accuracy was observed for the identification of crystals, mitoses, necrosis, hemosiderin, and nucleoli. Participant pathologists and residents preferred the use of larger displays (>30″) with a higher pixel count, resolution, and luminance.

CONCLUSION

Most features can be identified using any display. However, certain features posed more challenges across the three fixed display types. Furthermore, the use of a remote personal consumer-grade display chosen according to the pathologists' preference showed similar feature identification accuracy. Several factors of display characteristics seemed to influence pathologists' display preferences such as the display size, color, contrast ratio, pixel count, and luminance calibration. This study supports the use of standard "unlocked" vendor-agnostic displays for clinical digital pathology workflow rather than purchasing "locked" and more expensive displays that are part of a digital pathology system.

Iron-laden blasts in refractory acute myeloid leukemia

We report a case of refractory acute myeloid leukemia with DEK-NUP214 rearrangement showing circulating monocytic blasts with abundant green cytoplasmic granules on the Wright-Giemsa stain. The granules were strongly positive for Perls' Prussian blue, consistent with hemosiderin deposits. This previously unreported finding is suggestive of siderophage activity by leukemic blasts, likely associated with monocytic differentiation.

Chronic kidney disease in a giant panda (Ailuropoda melanoleuca): a case report

BACKGROUND

Chronic kidney disease (CKD) is a common cause of morbidity and mortality in captive wildlife species. However, CKD has been rarely documented in giant pandas.

CASE PRESENTATION

The following report describes a case of an eight-year-old female giant panda showing clinical signs of epistaxis, bloody diarrhea, polyuria, azotemia and anemia. The animal died despite of supportive treatments. Necropsy was performed. Grossly, both kidneys were shrunken and scarred with pallor. Subcutis edema and petechia on the epicardium of the heart were observed. The tissue samples were made into paraffin sections and stained by H.E and special staining including Periodic Acid-Schiff (PAS), von Kossa, Masson's trichrome, Phosphotungstic acid-hematoxylin (PTAH), and Congo red. Histopathology examination revealed severe chronic tubulointerstitial nephritis with marked interstitial fibrosis, glomerulosclerosis, tubular atrophy and calcification in kidneys, and acute necrotizing hemorrhagic myocarditis with calcification in heart. Other lesions included intestinal hemorrhage, hepatic fatty degeneration and necrosis with hemosiderin, and splenic hemosiderin.

CONCLUSIONS

In summary, chronic kidney disease was finally diagnosed based on the association of clinical, gross, and histopathological findings. Heart failure secondary to CKD is the leading cause of death in this giant panda. The potential cause of CKD in this animal is possibly due to long term and uncontrolled hypertension. Blood pressure monitoring is essential in establishing the diagnosis and management of hypertension in giant panda.

Arteriolosclerosis differs from venular collagenosis in relation to cerebrovascular parenchymal damages: an autopsy-based study

BACKGROUND AND PURPOSE

Cerebrovascular parenchymal damage is prevalent in ageing brains; however, its vascular aetiology has not been fully elucidated. In addition to the underlying role of sclerotic arterioles, the correlation between collagenised venules has not been clarified. Here, we aimed to investigate the associations between microvascular injuries, including arteriolosclerosis and venular collagenosis, and related parenchymal damages in ageing brains, to investigate the underlying correlations.

METHODS

We evaluated arteriolosclerosis and venular collagenosis in 7 regions from 27 autopsy cases with no history of stroke or brain tumour. The correlations between the ratio of arteriolosclerosis, venular collagenosis and the severity of cerebrovascular parenchymal damage, including lacunes, microinfarcts, myelin loss, and parenchymal and perivascular haemosiderin deposits, were assessed.

RESULTS

Arteriolosclerosis and venular collagenosis became more evident with age. Arteriolosclerosis was associated with lacunes (p=0.004) and brain parenchymal haemosiderin deposits in the superior frontal cortex (p=0.024) but not with leukoaraiosis severity. Venular collagenosis was not associated with the number of lacunes or haemosiderin, while white matter generally became paler with severe venular collagenosis in the periventricular (β=-0.430, p=0.028) and deep white matter (β=-0.437, p=0.025).

CONCLUSION

Our findings imply an important role for venular lesions in relation to microvessel-related parenchymal damage which is different from that for arteriolosclerosis. Different underlying mechanisms of both cerebral arterioles and venules require further investigation.

Histotripsy Treatment of Murine Brain and Glioma: Temporal Profile of Magnetic Resonance Imaging and Histological Characteristics Post-treatment

OBJECTIVE

Currently, there is a knowledge gap in our understanding of the magnetic resonance imaging (MRI) characteristics of brain tumors treated with histotripsy to evaluate treatment response as well as treatment-related injuries. Our aim was to bridge this gap by investigating and correlating MRI with histological analysis after histotripsy treatment of mouse brain with and without brain tumors and evaluating the evolution of the histotripsy ablation zone on MRI over time.

METHODS

An eight-element, 1 MHz histotripsy transducer with a focal distance of 32.5 mm was used to treat orthotopic glioma-bearing mice and normal mice. The tumor burden at the time of treatment was ∼5 mm3. T2, T2*, T1 and T1-gadolinium (Gd) MR images and histology of the brain were acquired on days 0, 2 and 7 for tumor-bearing mice and days 0, 2, 7, 14, 21 and 28 post-histotripsy for normal mice.

RESULTS

T2 and T2* sequences most accurately correlated with histotripsy treatment zone. The treatment-induced blood products, T1 along with T2, revealed blood product evolution from oxygenated, de-oxygenated blood and methemoglobin to hemosiderin. And T1-Gd revealed the state of the blood-brain barrier arising from the tumor or histotripsy ablation. Histotripsy leads to minor localized bleeding, which resolves within the first 7 d as evident on hematoxylin and eosin staining. By day 14, the ablation zone could be distinguished only by the macrophage-laden hemosiderin, which resides around the ablation zone, rendering the treated zone hypo-intense on all MR sequences.

CONCLUSION

These results provide a library of radiological features on MRI sequences correlated to histology, thus allowing for non-invasive evaluation of histotripsy treatment effects in in vivo experiments.

Extrastriatal 99m Tc-TRODAT-1 Uptake in the Previous Hemorrhage With Hemosiderin Deposition

ABSTRACT

We reported a 91-year-old man who was suspected of having parkinsonism, and brain 99m Tc-TRODAT-1 scan revealed an extrastriatal uptake in the left side of brainstem, which was correlated to a previously hemorrhagic lesion with hemosiderin deposition. Macrophage or microglia might accumulate in the previous hemorrhagic lesion to phagocytize hemosiderin. We assumed that the 99m Tc-TRODAT-1 uptake in the hemosiderin deposition might be partially mediated by macrophage expressing dopamine transporter.

Neuropathology of microbleeds in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL)

Cerebral microbleeds (CMBs) detected on magnetic resonance imaging are common in patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). The neuropathologic correlates of CMBs are unclear. In this study, we characterized findings relevant to CMBs in autopsy brain tissue of 8 patients with genetically confirmed CADASIL and 10 controls within the age range of the CADASIL patients by assessing the distribution and extent of hemosiderin/iron deposits including perivascular hemosiderin leakage (PVH), capillary hemosiderin deposits, and parenchymal iron deposits (PID) in the frontal cortex and white matter, basal ganglia and cerebellum. We also characterized infarcts, vessel wall thickening, and severity of vascular smooth muscle cell degeneration. CADASIL subjects had a significant increase in hemosiderin/iron deposits compared with controls. This increase was principally seen with PID. Hemosiderin/iron deposits were seen in the majority of CADASIL subjects in all brain areas. PVH was most pronounced in the frontal white matter and basal ganglia around small to medium sized arterioles, with no predilection for the vicinity of vessels with severe vascular changes or infarcts. CADASIL subjects have increased brain hemosiderin/iron deposits but these do not occur in a periarteriolar distribution. Pathogenesis of these lesions remains uncertain.

Low-temperature Mössbauer spectroscopy of organs from 57Fe-enriched HFE(-/-) hemochromatosis mice: an iron-dependent threshold for generating hemosiderin

Hereditary hemochromatosis is an iron-overload disease most often arising from a mutation in the Homeostatic Fe regulator (HFE) gene. HFE organs become overloaded with iron which causes damage. Iron-overload is commonly detected by NMR imaging, but the spectroscopic technique is insensitive to diamagnetic iron. Here, we used Mössbauer spectroscopy to examine the iron content of liver, spleen, kidney, heart, and brain of 57Fe-enriched HFE(-/-) mice of ages 3-52 wk. Overall, the iron contents of all investigated HFE organs were similar to the same healthy organ but from an older mouse. Livers and spleens were majorly overloaded, followed by kidneys. Excess iron was generally present as ferritin. Iron-sulfur clusters and low-spin FeII hemes (combined into the central quadrupole doublet) and nonheme high-spin FeII species were also observed. Spectra of young and middle-aged HFE kidneys were dominated by the central quadrupole doublet and were largely devoid of ferritin. Collecting and comparing spectra at 5 and 60 K allowed the presence of hemosiderin, a decomposition product of ferritin, to be quantified, and it also allowed the diamagnetic central doublet to be distinguished from ferritin. Hemosiderin was observed in spleens and livers from HFE mice, and in spleens from controls, but only when iron concentrations exceeded 2-3 mM. Even in those cases, hemosiderin represented only 10-20% of the iron in the sample. NMR imaging can identify iron-overload under non-invasive room-temperature conditions, but Mössbauer spectroscopy of 57Fe-enriched mice can detect all forms of iron and perhaps allow the process of iron-overloading to be probed in greater detail.

Clinical characteristics and risk factors of cerebral cavernous malformation-related epilepsy

PURPOSE

This study aimed to summarize the clinical characteristics and explore the risk factors for cerebral cavernous malformation (CCM)-related epilepsy (CRE).

METHODS

We retrospectively analyzed the clinical data of patients with CCM in our cerebral vascular malformations database. Descriptive statistics were used to present the clinical characteristics of CRE patients. Patients were divided into a CRE and a non-CRE group according to clinical presentation. Binary logistic regression analysis was used to analyze the risk factors of CRE.

RESULTS

A total of 199 patients with CCM confirmed by postoperative pathological examination were enrolled, 93 of whom were diagnosed with CRE, and 34 patients had drug-resistant epilepsy. The most common seizure type of CRE patients was focal to bilateral tonic-clonic seizure (FBTCS), followed by focal impaired awareness motor seizure. All CCM lesions were supratentorial, 97.8% of which involved the cerebral cortex, 86.0% of lesions had hemosiderin rim, and 50.5% of lesions were located in the temporal lobe. Binary logistic regression analysis indicated that CCM diagnosis age ≤ 44 years (odds ratio [OR] 2.79, p = 0.010), temporal lobe lesion location (OR = 9.07, p = 0.042), medial temporal lobe lesion (OR = 14.09, p = 0.002), cortical involvement of the lesion (OR = 32.77, p = 0.010), and hemosiderin rim around the lesion (OR = 16.48, p = 0.001) significantly increased the risk of CRE.

CONCLUSIONS

The most common seizure type of CRE was FBTCS. Those whose CCM diagnosis age was ≤ 44 years, having a temporal lobe lesion location, especially the medial temporal lobe lesion, cortical involvement, and hemosiderin rim around the lesion had a higher risk of developing CRE.

Hemosiderin-Laden Macrophages in Bronchoalveolar Lavage Samples of Children with Bronchopulmonary Dysplasia

OBJECTIVES

To evaluate the prevalence of hemosiderin-laden macrophages in children with bronchopulmonary dysplasia (BPD) and assess for an association between hemosiderin-laden macrophages and pulmonary arterial hypertension.

STUDY DESIGN

Retrospective case-control study of infants and children with and without BPD who underwent bronchoscopy with bronchoalveolar lavage (BAL) the at Children's Hospital of Philadelphia between 2012 and 2021.

RESULTS

BAL from 205 children with BPD and 106 controls without BPD matched for tracheostomy, infection, and age were reviewed for hemosiderin-laden macrophages. Seventy-one individuals (34.6%) with BPD had a BAL with 10% or more hemosiderin-laden macrophages compared with 3 (2.8%) controls (P < .0001; OR, 18.19; 95% CI, 5.57-59.41). Patients with pulmonary hypertension by echocardiogram (P = .04; OR, 3.69; 95% CI, 1.05-12.96) or an elevated mean pulmonary artery pressure during cardiac catheterization, r_s (14) = 0.56, P = .04, were more likely to have elevated hemosiderin-laden macrophages on BAL samples less than 60 days from bronchoscopy. After adjusting for birth weight, gestational age, BPD grade, and age at the time of bronchoscopy using logistic regression, pulmonary hypertension was associated with a higher odds of hemosiderin-laden macrophages of 10% or more (P = .02; OR, 6.37; 95% CI, 1.28-31.87). No association was observed between hemosiderin-laden macrophages and sex, race, gestational age, birth weight, tracheostomy, or infectious studies.

CONCLUSIONS

This retrospective study revealed increased hemosiderin-laden macrophages in BAL samples from patients with BPD and a significant association with pulmonary arterial hypertension. It is unclear whether elevated hemosiderin-laden macrophages within BPD contributes to the pathogenesis of lung and pulmonary vascular disease or is simply a biomarker of pulmonary arterial hypertension.

Cytologic scoring of equine exercise-induced pulmonary hemorrhage: Performance of human experts and a deep learning-based algorithm

Exercise-induced pulmonary hemorrhage (EIPH) is a relevant respiratory disease in sport horses, which can be diagnosed by examination of bronchoalveolar lavage fluid (BALF) cells using the total hemosiderin score (THS). The aim of this study was to evaluate the diagnostic accuracy and reproducibility of annotators and to validate a deep learning-based algorithm for the THS. Digitized cytological specimens stained for iron were prepared from 52 equine BALF samples. Ten annotators produced a THS for each slide according to published methods. The reference methods for comparing annotator's and algorithmic performance included a ground truth dataset, the mean annotators' THSs, and chemical iron measurements. Results of the study showed that annotators had marked interobserver variability of the THS, which was mostly due to a systematic error between annotators in grading the intracytoplasmatic hemosiderin content of individual macrophages. Regarding overall measurement error between the annotators, 87.7% of the variance could be reduced by using standardized grades based on the ground truth. The algorithm was highly consistent with the ground truth in assigning hemosiderin grades. Compared with the ground truth THS, annotators had an accuracy of diagnosing EIPH (THS of < or ≥ 75) of 75.7%, whereas, the algorithm had an accuracy of 92.3% with no relevant differences in correlation with chemical iron measurements. The results show that deep learning-based algorithms are useful for improving reproducibility and routine applicability of the THS. For THS by experts, a diagnostic uncertainty interval of 40 to 110 is proposed. THSs within this interval have insufficient reproducibility regarding the EIPH diagnosis.

Iron-containing pathologies of the spleen: magnetic resonance imaging features with pathologic correlation

Systemic and non-systemic pathologies that involve iron deposition within the spleen have characteristic features on MRI due to the susceptibility properties of deposited iron, or hemosiderin. These lesions will have signal loss on longer echo sequences due to the T2* effect when evaluated with dual-echo gradient-echo sequences. The pathophysiology of systemic and localized iron sequestration disease processes can elucidate an underlying diagnosis based on these imaging features in conjunction with clinical information.

Superficial siderosis of the central nervous system associated with ventral dural defects: bleeding from the epidural venous plexus

OBJECTIVE

Superficial siderosis of the central nervous system is a rare intractable disease induced by chronic subarachnoid hemorrhage. Neurological deficits, such as cerebellar ataxia and hearing difficulties, gradually progress if left undiagnosed. Hemosiderin deposition is irreversible because standard medical treatment has not yet been established. Interventions at the source of bleeding may be the key to a preferable outcome of treatment for chronic subarachnoid hemorrhage; however, the source is not clear in many cases.

METHODS

Among the consecutive cases diagnosed with a spontaneous cerebrospinal fluid (CSF) leak, cases of superficial siderosis associated with a CSF leak due to a ventral dural defect were retrospectively analyzed.

RESULTS

Among 77 cases of a CSF leak, 7 cases (9%) of superficial siderosis were identified (median age of 59 years, male, 4 cases). Defects were diagnosed on 1-mm sliced fast imaging employing steady-state acquisition MRI (n = 5), conventional myelographic CT (n = 1), or dynamic myelographic CT (n = 1) at high thoracic levels (T1-T4). All defects were repaired by direct neurosurgery. During surgery, continuous bleeding from the epidural veins of the internal vertebral venous plexus was identified as the source of subarachnoid hemorrhage. Epidural CSF pulsations through the defect prevented clot formation by the epidural veins. Dural repair stopped free communication between the subarachnoid and epidural spaces, leading to the disappearance of chronic subarachnoid hemorrhage.

CONCLUSION

Bleeding from the epidural venous plexus may be the cause of superficial siderosis associated with ventral dural defects. Neurosurgical repair may stop the progression of this condition.

Superficial siderosis and intracranial hypotension syndrome following brachial plexus avulsion injury. A case of surgical treatment

Superficial siderosis (SS) is a slowly progressive neurodegenerative disorder caused by persistent or intermittent bleeding into the subarachnoid space. It leads to characteristic clinical and radiographic findings. Dural pathology is believed to be the most common identifiable etiology of SS. It has been suggested that dural tear may be the common pathology of both SS and intracranial hypotension syndrome. We present a patient with SS caused by posttraumatic duropathy that was associated with cerebrospinal fluid (CSF) hypotension headache. Patient was treated surgically with stabilization of neurological deficit and orthostatic headache improvement. It supports the speculated link between both entities and may confirm surgery being a reasonable approach in patients with SS.

Haemosiderin cap sign in cervical intramedullary schwannoma mimicking ependymoma: how to differentiate?

A 37-year-old female presented with gradually progressive asymmetric ascending paraesthesia and weakness involving bilateral upper and lower limbs. The MRI spine images revealed expansile intramedullary, solid cystic, peripherally enhancing lesion with a haemosiderin cap along the lower margin. The lesion extended into the left C5 and C6 nerve root exit zones, along with thickening and enhancement of the nerve roots. She underwent excision of the lesion, which revealed intramedullary schwannoma on histopathological examination. Presence of the cap, an extension of the lesion into the nerve root exit zone, with associated thickening and enhancement of the dorsal nerve roots should alert the radiologist to consider the possibility of intramedullary schwannoma rather than ependymoma. Schwannoma showing compact Antoni A area with Schwannian whorls and nuclear palisades (A,B) and loose Antoni B area with haemosiderin pigment (C). The tumour exhibits diffuse positivity for S-100 protein (D) and negativity for GFAP (E). [Stain: A-C: Haematoxylin and Eosin; D,E: Immunoperoxidase. Magnification = Scale Bar, A-E: 100μm].

[Clinical significance of cerebral microbleed and its diagnostic criteria]

Cerebral microbleed (CMB) on gradient-echo T2*-weighted MR imaging (T2*-w MR imaging) is associated with microangiopathy. Number of CMBs and new appeared CMBs are markers for stroke recurrence and the performance state. After CMB was reviewed in this manuscript, criterion for CMB is proposed as below. (1) Only microbleed associated with microangiopathies related to primary intracerebral hemorrhage or lacunar infarction is diagnosed as CMB. (2) A low intensity (round or oval shape, <7 mm in diameter) on T2*-w MR imaging defined as a CMB. Exception: (A) Micro-bleedings associated with trauma (cerebral concussion), brain tumor, cavernous angioma, or moyamoya disease are excluded. (B) Calcifications or vascular flow voids were excluded by CT or other MR imagings. Reference: (C) CMB is rarely correlated to a focal neurological sign. (D) CMB is associated with risk factors including hypertension, diabetes mellitus, or high age. CMB is very rare in patients less than 40 years old.

Silent cerebral microbleeds on T2*-weighted MRI: correlation with stroke subtype, stroke recurrence, and leukoaraiosis

BACKGROUND AND PURPOSE

Gradient-echo T2*-weighted MRI is uniquely sensitive to detect silent, old hemosiderin deposits, but the clinical significance of such "microbleeds" remains to be determined. Therefore, we investigated the incidence and the number of microbleeds among different stroke subtypes and the correlation with stroke recurrence and the severity of leukoaraiosis.

METHODS

This study consisted of 213 patients (73.5+/-9.1 years old, 104 men and 109 women), who were classified according to stroke subtypes into atherothrombotic infarction (24 patients), cardioembolic infarction (23 patients), lacunar infarction (66 patients), intracerebral hemorrhage (35 patients), and control (65 patients) groups. Gradient-echo T2*-weighted MRI was performed with a 1.5 T system, and asymptomatic microbleeds were located and counted.

RESULTS

The incidence and the number of microbleeds were significantly greater in patients with intracerebral hemorrhage (71.4% and 9.1+/-13.8, respectively) and lacunar infarction (62.1% and 7.4+/-16.1) compared with patients with cardioembolic infarction (30.4% and 2.5+/-5.6), atherothrombotic infarction (20.8% and 0.63+/-1.53), and controls (7.7% and 0.09+/-0.34). There was a correlation between the number of microbleeds and the severity of periventricular hyperintensity (r=0.626, P<0.0001). There was also a correlation between the number of microbleeds and the number of intracerebral hemorrhages (r=0.689, P<0.0001) or lacunar infarctions (r=0.514, P<0.0001). The locations of microbleeds were subcortical white matter (31.8%), thalamus (24.8%), basal ganglia (19.8%), brain stem (12.0%), and cerebellum (11.7%).

CONCLUSIONS

The findings suggest that microbleeds on T2*-weighted MRI are an indicator of advanced small artery disease of the brain with an increased risk for bleeding. This result should be taken into consideration when treating patients with stroke, and further studies are required.

The cellular transformation of injected colloidal iron complexes into ferritin and hemosiderin in experimental animals; a study with the aid of electron microscopy

As revealed by electron microscopy and electron diffraction, the physical state of ferric hydroxide micelles contained in iron-dextran, saccharated iron oxide, and hydrous ferric oxide ("ferric hydroxide") differs notably from the state of the ferric hydroxide in ferritin or hemosiderin. By virtue of this difference one can trace the intracellular transformation of colloidal iron, administered parenterally, into ferritin and hemosiderin. One hour after intraperitoneal injection of iron-dextran or saccharated iron oxide into mice, characteristic deposits were present in splenic macrophages, in sinusoidal endothelial cells of spleen and liver, and in vascular endothelial cells of various renal capillaries. Four hours after injection, small numbers of ferritin molecules were identifiable about intracellular aggregates of injected iron compounds; and by the 6th day, ferritin was abundant in close proximity to deposits of injected iron compounds. The latter were frequently situated in cytoplasmic vesicles delimited by single membranes. These vesicles were most frequently found in tissue obtained during the first 6 days after injection; and in certain of the vesicles ferritin molecules surrounded closely packed aggregates of injected material. Much unchanged ferric hydroxide was still present in macrophages and vascular endothelial cells 3 to 4 weeks after injection. While electron microscopy left no doubt about the identity of injected ferric hydroxide on the one hand, and of ferritin or hemosiderin on the other, histochemical tests for iron failed in this respect. Precipitation of ferric hydroxide (hydrous ferric oxide) from stabilized colloidal dispersions of iron-dextran was brought about in vitro by incubation with minced mouse tissue (e.g. liver), but not by incubation with mouse serum or blood. Subcutaneous injections of hydrous gel of ferric oxide into mice initially produced localized extracellular precipitates. Most of the material was still extracellular 16 days after injection, though part of it was phagocytized by macrophages near the site of injection; but apparently none reached the spleen in unaltered form. Five days after injection and thereafter, much ferritin was present in macrophages about the site of injection and in the spleen. The findings show that iron preparations widely used in therapy can be identified within cells, and that their intracellular disposition and fate can be followed at the molecular level. Considered in the light of previous work, they indicate that the characteristic structure of the ferric hydroxide micelles in molecules of ferritin is specific, and develops during the union of apoferritin with ferric hydroxide. Apparently this union does not depend upon specific cell components.

Alveolar haemorrhage in a case of high altitude pulmonary oedema

A case of high altitude pulmonary oedema (HAPE) in a climber who made a rapid ascent on Mt McKinley (Denali), Alaska is described. The bronchoalveolar lavage (BAL) fluid contained increased numbers of red blood cells and an abundance of haemosiderin laden macrophages consistent with alveolar haemorrhage. The timing of this finding indicates that alveolar haemorrhage began early during the ascent, well before the onset of symptoms. Although evidence of alveolar haemorrhage has been reported at necropsy in individuals dying of HAPE, previous reports have not shown the same abundance of haemosiderin laden macrophages in the BAL fluid. These findings suggest that alveolar haemorrhage is an early event in HAPE.

Hemosiderin deposition on the renal cortex by mechanical hemolysis due to malfunctioning prosthetic cardiac valve: report of MR findings in two cases

We present two cases of mechanical hemolysis due to malfunctioning prosthetic cardiac valves in which MRI was characteristic. The signal intensity of the renal cortex was much lower than that of the medulla on T2-weighted images due to deposition of hemosiderin in proximal convoluted tubules by intravascular hemolysis. These MR findings are identical to those in paroxysmal nocturnal hemoglobinuria.

The nature of storage iron in idiopathic hemochromatosis and in hemosiderosis. Electron optical, chemical, and serologic studies on isolated hemosiderin granules

Using three different methods of cells fractionation, hemosiderin granules were isolated from tissues (liver and/or spleen) of three patients. The samples were obtained from a case of idiopathic hemochromatosis, a case of thalassemia major with secondary (transfusional?) hemosiderosis, and a case of transfusional hemosiderosis associated with an unclassified anemia. Iron, nitrogen, and protein content of the hemosiderin granules varied over a wide range. Electron microscopy of sectioned granules revealed aggregates of dense particles of different shapes, with diameters ranging from 10 A to about 75 A. In some of the granules dense particles corresponding to the iron hydroxide micelles of ferritin molecules were abundant. But many of the granules contained very few of these molecules. The presence of ferritin and apoferritin in the samples of hemosiderin granules was demonstrated by means of precipitin tests in agar-gel, using rabbit antiferritin sera with known antibody nitrogen concentrations. At least three antigenic components were detected in highly purified crystalline ferritin prepared from tissues of the three patients; the hemosiderin granules contained the same antigens, but probably in much smaller quantities. Both ferritin and apoferritin molecules were extracted from hemosiderin granules, and were demonstrated in the electron microscope after suitable preparation. The solubility curve of human ferritin in solutions of (NH₄)₂SO₄ was investigated. The results indicate that substantial quantities of ferritin or apoferritin can be lost in saline, aqueous media during isolation of hemosiderin granules from cells. It was shown by means of electron microdiffraction on selected hemosiderin granules that the dense particles represent forms of partly hydrated α-Fe₂O₃. The conditions necessary for electron microdiffraction in an electron microscope precluded an exact determination of the state of hydration of the α-Fe₂O₃ or of its structural relation to (FeOOH) micelles of pure ferritin in its undenatured state. The findings were considered in the light of evidence on the structure and disposition of hemosiderin in situ in cells, and on the structure of ferritin. Differences between endogenous hemosiderin and hemosiderin derived from injections of colloidal iron compounds were pointed out. The evidence indicates that in hemochromatosis and in secondary hemosiderosis much of the inorganic storage iron in liver and spleen is derived from degraded ferritin. The findings suggest that an abnormal cellular metabolic pathway of ferritin is implicated in the pathogenesis of hemochromatosis and transfusional hemosiderosis.

Surgical outcome in patients with epilepsy with occult vascular malformations treated with lesionectomy

PURPOSE

This retrospective study reports the long-term surgical outcome of patients with medically refractory epilepsy and vascular malformations who were treated with lesionectomy. A detailed analysis of surgical failures had been performed in an attempt to define predictors of surgical success and failure.

METHODS

Fifteen patients with medically intractable epilepsy and angiographically occult vascular malformations (AOVMs) were treated surgically with lesionectomy at Duke University Medical Center. Lesionectomy consisted of removal of the AOVM and surrounding hemosiderin-stained brain only, without the use of electrocorticography (ECoG) to guide resection.

RESULTS

Eleven (73%) patients are seizure free after lesionectomy. Three showed no significant improvement, and one patient died, presumably after a seizure. Age of onset, duration of seizures, age at resection, and gender did not affect outcome. All patients with neocortical AOVMs in whom EEG findings correlated with the site of the lesion were seizure free after lesional resection. Treatment failures were associated with the presence of multiple intracranial lesions, poorly localized or diffuse EEG findings, discordant positron emission tomography (PET) imaging, or with a lesion in close proximity to the limbic system.

CONCLUSIONS

Lesionectomy, with removal of surrounding hemosiderin-stained brain, can be considered the procedure of choice in carefully selected patients with epilepsy with occult vascular malformations.

THE SEPARATION OF FERRITIN AND HAEMOSIDERIN FOR STUDIES IN THE METABOLISM OF IRON

1. Ferritin and haemosiderin in diluted tissue cannot be quantitatively separated by centrifugation unless the pH is brought below 6. 2. These iron-storage substances can be separated from one another and from haemoglobin by ion-exchange chromatography on CM-cellulose, when good recoveries of total tissue iron are obtained. 3. The ferritin fraction has been identified by its solubility, its appearance under the electron microscope, crystallization with Cd(2+) and the fact that it corresponds quantitatively to the heat-stable portion of the tissue non-haem iron.

Pulmonary capillaritis and alveolar hemorrhage. Update on diagnosis and management

Pulmonary vascular inflammatory disorders may involve all components of the pulmonary vasculature, including capillaries. The principal histopathologic features of pulmonary capillaritis include capillary wall necrosis with infiltration by neutrophils, interstitial erythrocytes, and/or hemosiderin, and interalveolar septal capillary occlusion by fibrin thrombi. Immune complex deposition is variably present. Patients often present clinically with diffuse alveolar hemorrhage, which is characterized by dyspnea and hemoptysis; diffuse, bilateral, alveolar infiltrates on chest radiograph; and anemia. Pulmonary capillaritis has been reported with variable frequency and severity as a manifestation of Wegener's granulomatosis, microscopic polyarteritis, systemic lupus erythematosus, Goodpasture's syndrome, idiopathic pulmonary renal syndrome, Behçet's syndrome, Henoch-Schönlein purpura, IgA nephropathy, antiphospholipid syndrome, progressive systemic sclerosis, and diphenylhydantoin use. In addition to history, physical examination, and routine laboratory studies, certain ancillary laboratory tests, such as antineutrophil cytoplasmic antibodies, antinuclear antibodies, and antiglomerular basement membrane antibodies, may help diagnose an underlying disease. Diagnosis of pulmonary capillaritis can be made by fiberoptic bronchoscopy with transbronchial biopsy, but thoracoscopic biopsy is often employed. Since many disorders can result in pulmonary capillaritis with diffuse alveolar hemorrhage, it is crucial for clinicians and pathologists to work together when attempting to identify an underlying disease. Therapy depends on the disorder that gave rise to the pulmonary capillaritis and usually includes corticosteroids and cyclophosphamide or azathioprine. Since most diseases that result in pulmonary capillaritis are treated with immunosuppression, infection must be excluded aggressively.

True proton density and T2-weighted turbo spin-echo sequences for routine MRI of the brain

Our aim was to evaluate the diagnostic reliability of turbo spin-echo (TSE) sequences compared to a conventional dual-echo spin-echo (SE) sequence in routine brain MRI at 1.0 T. The following demands were made on TSE sequences: acquisition time-reduction of at least 50% and true proton density (PD) contrast (low-signal cerebrospinal fluid). A conventional spin-echo and two single-echo TSE sequences were used in 150 patients, a dual-echo TSE sequence in addition in 50 patients. Demonstration of most anatomical structures and disorders was equivalent with TSE and SE sequences. Advantages of TSE were reduced flow artefacts on T2-weighted images, better lesion contrast on PD-weighted TSE images (especially in the dual-echo sequence) and acquisition time reduction to about 5 min (single-echo TSE) and 3:35 min (dual-echo TSE). Disadvantages of TSE were: reduced contrast of iron-containing substances such as haemosiderin and of areas of calcification. By virtue of the shorter acquisition time and diagnostic reliability dual-echo TSE proved the best sequence. If it is used with only one acquisition--whereby image quality but not diagnostic reliability is slightly decreased--acquisition time can be further reduced to 1:48 min. Application of a susceptibility-sensitive gradient-echo sequence, such as FLASH, compensates for the disadvantages mentioned above.