Munro and merritt dating subdural clot

Histologic Dating of Subdural Hematoma An early attempt at histologic of the dura overlying the hematoma was that of Munro and Merritt,56 and several. Subdural clot having red blood cells of normal size, shape and uniform .. Though Munro and Merritt made no mention of the duration of appearance of the . Richards, Charles E., "Chronic subdural hematoma: with special reference to etiology, diagnosis, and treatment" (). MD Theses. .. still calls one of the finest descriptions to date. . An exceedingly important paper by Munro and Merritt.

Here is where an argument can be made for a short interval repeat CT examination within 24 to 48 hours of the initial study to clarify hypodense or isodense subdural components. Using MR as a means of dating subdural hemorrhage is even more complex than CT dating for reasons mentioned above. Although the work by Bradley has laid a foundation for our understanding of the MR evolution of intracranial hemorrhage, it must be kept in mind that the MRI evolutionary findings of intracranial hemorrhage are observations drawn from intraparenchymal hematoma aging Table 2.

Four diagnostic considerations should come to mind for the radiologist in the setting of mixed density SDH. In my experience, the mixed density SDH associated with ipsilateral cerebral edema is usually associated with one of the first three causes. Tung and colleagues reported that SDH in the context of abusive head trauma was more likely to be mixed density, bilateral in location, contrecoup, and affiliated with poor neurological outcome.

SDH of accidental cause was more homogeneous, unilateral and coup to the site of impact Fig 2. For purposes of dating, the radiologist should focus upon the CT and MR features of the sediment for most accurately estimating hemorrhage age Fig 3. Delicate incomplete membranes begin to form within the subdural hemorrhage within 2 to 3 weeks and mature by 4 to 5 weeks.

Subdural Hemorrhage in Abusive Head Trauma: Imaging Challenges and Controversies

Membrane detection requires careful inspection of all pulse sequences. Membrane conspicuity may be heightened by the use of intravenous MR contrast and post-contrast T1 weighting and subtraction MR imaging techniques. Additionally, the radiologist should always keep in the back of his or her mind the possibility of non-traumatic causes of SDH and re-bleeding as one might see with a progressive neurodegenerative disorder Table 3. Birth related subdural hemorrhage Birth related SDH can lead to confusion and controversy particularly when SDH is detected in a young infant.

Additionally, in the first three days of life, hemorrhage was most accurately detected with gradient recall imaging GRE at a time when acute hemorrhage was isointense on T1 weighted images. The etiology of these collections likely represents a transient mismatch between CSF production and resorption. Additionally, during infancy, the inner dural border zone may play an important role in CSF resorption at a time of evolving arachnoid granulation maturation.

There are authors who posit that in the context of benign expanded subarachnoid spaces that SDH can occur spontaneously or with minimal trauma. Therefore, in my clinical practice, the detection of SDH in association with benign expanded subarachnoid CSF collections warrants a comprehensive child protection team evaluation.

Subdural hemorrhage and intracranial venous thrombosis In the differential diagnostic consideration of non-traumatic causes of SDH, some authors opine and testify to the fact that intracranial venous thrombosis ICVT may lead to the development of SDH that mimics the SDH of abusive head trauma.

Of course, trauma can be a cause for ICVT and subdural hemorrhage alike. Hypoxic ischemic encephalopathy and subdural hemorrhage Finally, there has been recent controversy raised over whether hypoxic ischemic encephalopathy HIE is a potent cause of SDH which may mimic the features of abusive head trauma. Of course, childbirth related subdural hemorrhage may occur in conjunction with HIE without a causal relationship.

It is worth remembering that physical abuse is more common among children with chronic illness. The law is clear in this regard. For the radiologist, there is a legal responsibility to report findings suspicious for AHT.

Dare to date: age estimation of subdural hematomas, literature, and case analysis

These guidelines are outlined by the American College of Radiology, and can be reviewed at http: Documentation of the individual contacted, the method of communication, the date and time are minimal requirements. As a mandatory reporter, the radiologist is protected from civil and criminal prosecution by Shield Laws that exist within the United States. Neuroimaging of abusive head trauma. Medina LS, et al. Imaging of nonaccidental head injury. Evidence-Based Imaging in Pediatrics ; Neuroimaging of nonaccidental head trauma; pitfalls and controversies.

Pediatric Radiol ; Barnes P, Krasnokutsky M. Top Magn Reson Imaging ; Wang CT, Holton J. Total estimated cost of child abuse neglect in the United States.

Prevent Child Abuse America Web site. Subdural hematoma and non-accidental head injury in children. Assessment of the nature and age of subdural collections in nonaccidental head injury with CT and MRI. Pediatric Radiol, ; Eur Radiol, ; MR characteristics of subdural hematomas and hygromas at 1.

The computed tomographic attenuation and the age of subdural hematomas. J Korean Med Sci ; Imaging of head injuries in infants: J Neurosurg Pediatrics 1 ; CT mimic of recurrent episodes of bleeding in the setting of child abuse. Magnetic resonance in imaging of chronic subdural hematoma. Neurosurg Clin N Am.

  • Subdural Hemorrhage in Abusive Head Trauma: Imaging Challenges and Controversies
  • Traumatic Subdural Hematoma—Acute, Subacute and Chronic

Comparison of accidental and nonaccidental traumatic head injury in children on noncontrast computed tomography. Comparison of intracranial computed tomographic findings in pediatric abusive and accidental head trauma. Pediatr Rad ; Munro D, Merritt H. Surgical pathology of subdural hematoma.

Based on a study of cases. The aetiology of subdural hematoma: J Nerv Ment Dis. Anatomy of an Autopsy

When the scalp is reflected, the pathologist may locate a fracture that escapes visual detection by percussing the exposed skull. The pathologist will then remove the skull cap, exposing the brain. The dura may be either adherent to the inner table of the skull, or covering the surface of the brain, depending on whether or not it has been cut when the skull cap is removed.

When the dura is cut and removed, a subdural hematoma may be seen. The pathologist should weigh volumesample and photograph this blood. It will appear the color of port wine, brown or yellow. It should be noted whether the blood is adherent to the skull cap, dura or elsewhere and if so, to what degree to aid in the timing and dating of the subdural.

Adherant blood is not accute in nature. If the blood is adherent, care should be taken to properly fix the specimen before attempting to make a tissue section, since the clot and other valuable information may be carried away in the process. Even apparently acute clots may have chronic elements within them that only histological study can reveal.

Dating of a subdural hematoma by visual inspection is unreliable, but histologically, using the Munro and Merritt chart, greater accuracy is possible. Although the Munro and Merritt dating concept was done from limited adult data, it is the most comprehensive study to date.

surgery for chronic subdural hematoma

There are no studies to indicate that the process of aging and dating subdurals in children is any different than adults. The arachnoid is the thin web-like membrane beneath the dura and covering the surface of the brain.