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In order to measure the effectiveness of new therapies a technique is needed which can measure quantitatively in vivo pathology. In cardiology, the introduction of thrombolytic agents, which lyse the initial thrombus, has given added stimulus to the search for techniques which would fill this role. In this paper the extent to which nuclear medicine and magnetic resonance imaging can meet the requirements is discussed.
This study was designed to assess the value of MRI of the postmortem brain specimens by comparing MRI findings with neuropathological findings. Postmortem MRI was performed in 17 consecutive formalin-fixed whole brains comprisig 3 with primary CNS neoplasm, 1 with metastatic brain tumor, 6 with cerebral vascular disease (CVD), 1 with degenerative disease, 1 with spongy state in thalamus, and 5 with no abnormality. Postmortem T2WI detected all neuropathological abnormalities but sparsely distributed tumor cells without edema. In one case of CNS neoplasm, the tumor lesions with little necrosis or edema showed isointensity to brain tissue, while others with large amounts of necrosis and edema showed high signal intensity on T2WI. In the cases of CVD, the major signal changes on T2WI were due to edema, necrosis, and damage of the organization as observed on neuropathological studies. There was one case in which both MRI and neuropathological examination showed an abnormality, which was pathologically unexplainable. In two cases, findings of postmortem MRI were more apparent than those of macroscopic examination. Postmortem MRI appeared different from premortem MRI in one of the rest three cases whereas the postmortem MRI correlated well with neuropathological findings. Progression of the disease immediately before death may have caused this difference. In conclusion, the correlations between MRI and neuropathological findings facilitate understanding the mechanisms responsible for MRI abnormalities. An increase in free water in edema, necrosis, and damage in brain tissue can explain an increased signal intensity on T2WI. Postmortem MRI may contribute to the effective pathological examination by pointing out subtle abnormalities before brain cutting.
PURPOSE: Solid tubular carcinoma of the breast is a recognizable histologic type of invasive ductal carcinoma, characterized by rare axillary lymph nodal metastases and a good prognosis. The purpose of this study is to describe the magnetic resonance (MR) characteristics of solid tubular carcinoma and to emphasize the spotty appearance on the MR subtraction images. MATERIALS AND METHODS: We reviewed the MR findings of seven patients with biopsy-proven solid tubular carcinoma. Two of the 7 cases were of the pure type (more than 85% solid tubular component) and the remaining 5 were of the mixed type (50% to 85% solid tubular component). The mean age of the patients was 56 years. RESULTS: The mean size of the lesions was 28 mm. On T1-weighted images four of the lesions were visible and three were not identified. After Gd-DTPA all the lesions were enhanced. On the subtraction images, g" popcorn" appearence areas were noted in the stained mass. CONCLUSION: Our preliminary results suggest that solid tubular carcinomas have a characteristic apperarence on the subtraction MR images.
Neuroendocrine tumors of the lung arise from Kulchitzky cells of the bronchial mucosa and comprise typical carcinoid, atypical carcinoid, large cell neuroendocrine carcinoma (LCNEC), and small cell lung cancer (SCLC). At histopathologic analysis, these tumors demonstrate a progressive increase in the number of mitotic figures per 10 high-power fields of viable tumor and in the extent of necrosis, with typical carcinoid having the lowest values and SCLC having the highest. Typical carcinoid is less aggressive than atypical carcinoid, although these tumors have similar gross pathologic and radiologic features; LCNEC has a prognosis between that of atypical carcinoid and that of SCLC. SCLC is the most aggressive pulmonary neuroendocrine tumor and has the most specific imaging feature: mediastinal or hilar lymphadenopathy. At CT, carcinoid tumors appear as a spherical or ovoid nodule or mass with a well-defined and slightly lobulated border. When nonspherical, the tumor is elongated with its long axis parallel to adjacent bronchi. Calcification or ossification is seen in up to 30% of cases. The CT findings of LCNEC are nonspecific and are similar to those of other non-small cell lung cancers. Although there are some overlapping features between these tumors, integration of the clinical and imaging features may be helpful in differentiation of pulmonary neuroendocrine tumors.
The authors report a 32-year-old woman who had undergone repair of an occipital encephalocele in infancy and who experienced a 20-year history of progressive hearing loss and intermittent vertigo. After parturition, she developed a rapidly progressive quadriparesis and brain-stem dysfunction associated with persistent intraventricular and subarachnoid hemorrhage. Serial magnetic resonance (MR) images showed progressive deposition of hemosiderin along the surface of the brain, brain stem, and spinal cord, and enhanced thickened membranes at the site of the original encephalocele repair. Posterior fossa exploration disclosed hemorrhagic membranes, which were resected; despite removal of this tissue, the patient deteriorated and died. Postmortem examination confirmed iron-containing pigment along the meninges, cerebral hemispheres, brain stem, spinal cord, and cranial nerves accompanied by atrophy of the superficial cerebellar cortex. It is concluded that superficial siderosis may accompany encephalocele repair. This is believed to be the first report in the literature of superficial siderosis of the central nervous system to correlate in vivo MR images with autopsy results.
BACKGROUND AND PURPOSE: A panencephalopathic type of Creutzfeldt-Jakob disease (pCJD) is characterized by the extensive involvement of the cerebral white matter as well as the cerebral gray matter. It has been a point of controversy, however, whether the white matter changes represent primary or secondary degeneration. The aim of this study was to elucidate, by using MR images and histologic examinations, whether the white matter lesions in pCJD are primary or secondary degeneration. METHODS: Serial changes of T2 hyperintensities and histologic findings of six autopsy-proved cases of pCJD were retrospectively analyzed. RESULTS: Serial MR images of brains affected by pCJD revealed that T2 hyperintensities appeared in the cerebral gray matter 2-5 months after onset and in the cerebral white matter around the lateral ventricles approximately 5 months after onset. They rapidly extended to deep and subcortical white matter during the next several months and then to the entire cerebral white matter 10 months after onset. Histologic examination of the white matter lesions revealed spongy changes or tissue rarefaction associated with gemistocytic astrocytosis, which indicates primary involvement of the white matter. At the terminal stages of cases with a longer clinical course, MR images showed T2 hyperintensities in the corticospinal tracts in the internal capsule and brain stem, which histologically disclosed loss of myelin and axons accompanied by fibrillary gliosis that indicates secondary degeneration. CONCLUSION: Cerebral white matter lesions in pCJD were considered to be primary changes of the disease, but the lesions of the corticospinal tracts were secondary to cortical or cerebral or both white matter lesions.
Thyroid acropachy is a rare manifestation of autoimmune thyroid disease, in the form of soft tissue swelling of the hands and feet with insidious onset, associated with clubbing and characteristic periosteal reactions. It is usually part of a syndrome consisting of a typical triad of thyroid acropachy, exophthalmos, and pretibial myxedema. The purpose of this case report is to demonstrate the imaging features of this typical triad in a 65-year-old-woman. This case is the first in which the MRI features of thyroid dermopathy are documented.
The presence, location and number of Schmorl's nodes was determined in the thoracolumbar spines of 70 motor vehicle accident victims using radiographic examination of a midline sagittal section and subsequent pathological examinations, including histology. In 28% of spines, a greater number of Schmorl's nodes were identified with radiography, while in 44%, pathological examination revealed a greater number of nodes. The visibility of Schmorl's nodes was enhanced by using a sagittal radiographic approach, and, in contrast to previous work, nodes below 0.5 cm2 were readily detected. The results of the present study offer an additional imaging technique for postmortem analysis of the spine, and support the use of sagittal MR imaging for the evaluation of this condition.
Hepatocellular adenoma is a rare benign lesion that is most often seen in young women with a history of oral contraceptive use. It is typically solitary, although multiple lesions have been reported, particularly in patients with glycogen storage disease and liver adenomatosis. Because of the risk of hemorrhage and malignant transformation, hepatocellular adenomas must be identified and treated promptly. At pathologic analysis, hepatocellular adenoma is usually a well-circumscribed, nonlobulated lesion, and at gross examination, resected adenomas frequently demonstrate areas of hemorrhage and infarction. Most adenomas are not specifically diagnosed at ultrasonography (US) and are usually further evaluated with computed tomography (CT) or other imaging modalities. Color Doppler US may help differentiate hepatocellular adenoma from focal nodular hyperplasia. Multiphasic helical CT allows more accurate detection and characterization of focal hepatic lesions. Hepatocellular adenomas are typically bright on T1-weighted magnetic resonance images and predominantly hyperintense relative to liver on T2-weighted images. The prognosis of hepatic adenoma is not well established. Criteria that guide treatment include the number and size of the lesions, the presence of symptoms, and the surgical risk incurred by the patient. Understanding the imaging appearance of hepatocellular adenoma can help avoid misdiagnosis and facilitate prompt, effective treatment.
OBJECTIVE: Our objective was to show the spectrum of biologic behavior associated with breast adenomyoepithelioma. This disease is a rare benign breast neoplasm characterized by proliferation of both epithelial and myoepithelial cellular elements. Malignant change of one or both cell types may occur and is thought to be associated with hematogenous, rather than lymphatic, metastasis. CONCLUSION: Three patients with benign and malignant adenomyoepithelioma were included in this study. The imaging and histopathologic findings in these three patients are illustrated, and the treatment of patients with this unusual tumor is discussed.
The purpose of this study was to correlate the MR features and histological findings of pleomorphic adenomas, which are the most common tumour of the parotid gland, and to distinguish them from other types of tumour in the parotid gland. The materials studied consisted of 20 pleomorphic adenomas, including 12 untreated and eight recurrent cases, 17 other benign parotid tumours, and 12 malignant tumours. T1- and T2-weighted images and Gd-DTPA enhanced T1-weighted images were obtained. Characteristic bright signals with a higher intensity than that of CSF were seen in all of the pleomorphic adenomas on T2-weighted images, and were found to represent myxoid areas histologically. Although the cystic spaces in some benign tumours produced bright signals, these areas were distinguished from myxoid areas due to nonenhancement with Gd-DTPA. No bright signals were seen in the malignant tumours. In conclusion, bright signals on T2-weighted images represent myxoid tissue and are useful findings for diagnosing pleomorphic adenomas.
Although glioblastoma multiforme (GBM), a World Health Organization grade IV astrocytoma, is the most common primary brain tumor in humans, in dogs GBM is relatively rare, accounting for only about 5% of all astrocytomas. This study presents combined clinical, neuroimaging, and neuropathologic findings in five dogs with GBM. The five dogs, aged from 5 to 12 years, were presented with progressive neurologic deficits that subsequent clinical neurologic examination and neuroimaging studies by magnetic resonance imaging (MRI), localized to space occupying lesions in the brain. MRI features of the tumors included consistent peritumoral edema (n = 5), sharp borders (n = 4), ring enhancement (n = 3), heterogenous T2-weighted signal intensity (n = 3), iso- to hypointense T1-weighted images (n = 5), necrosis (n = 5), and cyst formation (n = 2). Two tumors were diagnosed clinically using a computed tomography-guided stereotactic biopsy procedure. At necropsy all the tumors resulted in, on transverse sections, a prominent midline shift and had a variegated appearance due to intratumoral necrosis and hemorrhage. Histologically, they had serpentine necrosis with glial cell pseudopalisading and microvascular proliferation, features which distinguish human GBM from grade III astrocytomas. Immunoreactivity of tumor cells for glial fibrillary acidic protein was strongly positive in all cases, whereas 60% and 40% of the tumors also expressed epidermal growth factor receptor and vascular endothelial growth factor, respectively. These canine GBMs shared many diagnostic neuroimaging, gross, microcopic, and immunoreactivity features similar to those of human GBMs.
OBJECTIVE: The authors sought to expand on previous observations suggesting that body-image pathology is associated with illicit use of anabolic-androgenic steroids (AAS). In particular, the authors compared current versus past AAS users and short-term versus long-term users in this respect. METHOD: The authors assessed 89 heterosexual men who lifted weights regularly-48 AAS users and 41 nonusers-on measures of self-esteem, attitudes toward male roles, body image, eating-related attitudes and behaviors, and muscle dysmorphia ("reverse anorexia nervosa"). RESULTS: AAS users as a whole showed few differences from nonusers on most measures but showed greater symptoms of muscle dysmorphia (e.g., not allowing their bodies to be seen in public, giving up pleasurable activities because of body-appearance concerns). The current and past AAS users each differed only modestly from nonusers on most measures. Short-term AAS "experimenters" were also largely indistinguishable from nonusers, but the long-term AAS users showed striking and significant differences from nonusers on many measures, including marked symptoms of muscle dysmorphia and stronger endorsement of conventional male roles. CONCLUSIONS: Both body-image pathology and narrow stereotypic views of masculinity appear to be prominent among men with long-term AAS use. Although our cross-sectional observations cannot confirm that these factors help to cause or perpetuate AAS use, a causal hypothesis is certainly plausible and deserving of further testing in longitudinal studies. If these factors are indeed causal, then AAS users might respond to cognitive behavior approaches that simultaneously take aim at both types of maladaptive beliefs.
Lymphoscintigraphy usually involves labeled microparticles or colloids that distribute in the lymph flow. A new strategy for imaging pathological lymph nodes would be the targeting of macrophages recruited in these lesions. The potential for lymphoscintigraphy of the highly diffusible J001X acylated polygalactoside labeled with 99mTc was studied and compared to usual colloidal agents in a model of infectious granulomas developed in sheep. Scintigraphic and histological assessment of the specificity of targeting was performed using a MAb (OM1) raised against ovine macrophages taken as reference. This study has evidenced the ability of J001X specifically to image pathologic lymph nodes and more especially the second lymph node in the same chain with a significant scintigraphic contrast.
The pathological assessment of the pulmonary vascular bed is essential for the diagnosis and management of congenital heart disease with pulmonary hypertension. To investigate the relationship between intravascular ultrasound (IVUS) findings and the Heath-Edwards (H.E.) grade of human pulmonary arteries, 40 pulmonary arterial segments from 17 autopsies and 5 patients with pulmonary hypertension were evaluated using a high-frequency IVUS imaging system. Histological observations were carried out at the same sites that were examined with IVUS and at the distal pulmonary arterioles of the same branches. The subjects were subdivided into 3 groups-group I: 7 patients with pulmonary hypertension (20 segments); group II: 10 patients without pulmonary hypertension (20 segments); and group III: 5 patients with pulmonary hypertension who were studied in vivo. All 20 segments from group I had a three-layered appearance, and 3 patients with H.E. grade < 3 had an increased thickness of the echolucent zone due to media hypertrophy without an intimal reaction. In contrast, IVUS findings from patients with severe pulmonary hypertension (H.E. grade > or = 3) showed an increased thickness with a bright inner layer due to intima hyperplasia. Evidence for a plaque-like lesion was defined in one patient with severe pulmonary hypertension. The percentage of wall thickness derived from IVUS was significantly correlated with that determined by histological examination in group I. The pulmonary artery walls in group II had a one-layer appearance. Similar IVUS findings were obtained from the in vivo study regardless of whether pulmonary hypertension was present. These findings indicate that the IVUS may be an unique technique for evaluating the morphology of the pulmonary artery or arteriole in pulmonary hypertension and may provide objective and quantitative evaluation without a lung biopsy.
Primary germ cell neoplasms of the central nervous system typically develop as midline mass lesions during the first three decades of life. The authors present two cases with atypical clinicopathological features that stimulate discussion on the diagnosis and management of these tumors. The first patient was an 11-year-old boy of Japanese-American heritage who presented with a 6-month-long history of cognitive decline, difficulty swallowing, unsteady gait, and intermittent right-sided posturing. The initial magnetic resonance (MR) image of the brain displayed a mildly increased T2 signal in the cerebral peduncles, putamen, and globus pallidus bilaterally. Follow-up MR images showed an increase in the T2 signal abnormality in the left basal ganglia. The second patient was a 10-year-old Caucasian boy who presented with diabetes insipidus and subsequently displayed progressive fatigue, involuntary eye and mouth movements, and obsessive-compulsive behavior. An MR image demonstrated signs of mineral deposition and foci of increased T2 signal in both basal ganglia. Follow-up MR images demonstrated a progressive increase in the T2 signal (which was then located within the mesial temporal lobe). A biopsy performed on the left thalamic lesion in the first patient revealed a germinoma. The patient was treated with chemotherapy and died 2 years later. The second patient underwent a lumbar puncture, which demonstrated an elevated level of beta-human chorionic gonadotropin. Despite the lack of a mass on MR images in this child, the need for a tissue diagnosis prompted the authors to perform an anterior temporal lobectomy. The diagnosis of diffuse germinoma was confirmed, and the patient was treated with adjunctive chemotherapy. Although uncommon, germ cell tumors can present outside the midline and exhibit a multifocal growth pattern.
Necropsy was performed on a mongrel male cat of unknown age weighing 1.3 kg, which probably encountered a traffic accident. Gross pathological examination of the brain revealed reddish colour of the right cerebral hemisphere and haemorrhages on the surface of the right frontal lobe to temporal lobe. Histologically, there was diffuse vacuolation in the cortex of the right frontal lobe and extensive haemorrhages in the base of brain. These histopathological findings were consistent with areas of abnormal signals found on post-mortem magnetic resonance imaging (MRI). In this study, the MRI findings were identical to that reported in human cases of head trauma as well as histopathological changes.
Unilateral megalencephaly is a rare and poorly understood malformation resulting in the enlargement of all or part of a cerebral hemisphere. The clinical and radiologic features of 12 patients with unilateral megalencephaly are presented; pathologic correlation was available in four. All patients had seizures and developmental delay. Two were in congestive heart failure as a result of arteriovenous shunting through the abnormal hemisphere. The affected hemispheres showed a wide spectrum of involvement. Anomalies of neuronal migration were present, and there was a roughly inverse correlation between the severity of hemispheric involvement and the magnitude of enlargement. This correlation is explained via a proposed mechanism of a mild hemispheric insult in the middle-to-late second trimester. One patient had an extremely anomalous hemisphere that did not have characteristics of a neuronal migration anomaly and may have been a hamartomatous malformation. Our correlation of the clinical, radiologic, and pathologic features of unilateral megalencephaly, together with a theory of pathogenesis, should help elucidate this rare malformation.