Neurologic Imaging

What Is the Best Imaging Workup for a Proven Parenchymal Hemorrhage?

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What Is the Best Imaging Workup for a Proven Parenchymal Hemorrhage?

A 62-year-old male with a history of well-controlled hypertension presents to the emergency department with the sudden onset of a severe headache and left-sided weakness. The initial non-contrast head CT, performed emergently, confirms your suspicion: a 3 cm hematoma in the right temporal lobe. The immediate life-threat is being managed, but the critical clinical question shifts from what to why. You need to investigate for an underlying cause that could re-bleed or require urgent intervention. This article details the ACR-guided imaging workflow for a patient with a proven parenchymal hemorrhage. For this specific scenario, the American College of Radiology rates MRA head without and with IV contrast as Usually Appropriate.

## Who Fits the ‘Proven Parenchymal Hemorrhage’ Scenario?

This clinical workflow is designed for a specific patient population: individuals who have already undergone initial imaging (typically a non-contrast CT of the head) that has definitively identified a parenchymal hematoma. The primary diagnostic question is no longer “Is there a bleed?” but has evolved to “What is the underlying cause of this bleed?” This workup is crucial for identifying structural lesions that require specific management beyond supportive care and blood pressure control.

This guidance applies to patients with spontaneous, non-traumatic intracerebral hemorrhage. It is less applicable to patients whose hemorrhage is clearly secondary to severe trauma.

It is critical to distinguish this scenario from similar but distinct clinical presentations that follow different diagnostic pathways:

  • New Focal Neurologic Defect, Suspected Stroke: If a patient presents with stroke-like symptoms but hemorrhage has not yet been confirmed, the initial imaging choice is different. That workup is focused on rapidly differentiating ischemic from hemorrhagic stroke.
  • Suspected Dural Venous Sinus Thrombosis: If the clinical picture (e.g., headache in a young woman with risk factors, specific cranial nerve palsies) strongly suggests venous thrombosis as the primary event, the imaging protocol is tailored specifically to venous structures from the outset.
  • Isolated Subarachnoid, Subdural, or Epidural Hemorrhage: While these are also intracranial bleeds, their etiologies and imaging workups differ significantly from that of a primary parenchymal hematoma.

## What Diagnoses Are You Working Up After a Proven Parenchymal Hemorrhage?

Once a parenchymal hemorrhage is confirmed, the imaging goal is to search for a secondary cause. While chronic hypertension is the most common etiology, especially for deep hemorrhages (basal ganglia, thalamus, pons), a significant portion of bleeds, particularly those in lobar locations, are caused by underlying structural abnormalities. The differential diagnosis includes:

Underlying Vascular Malformation
This category includes several distinct pathologies. Arteriovenous malformations (AVMs) are high-flow tangles of abnormal vessels that directly connect arteries to veins without an intervening capillary bed, creating a high-risk nidus for rupture. Dural arteriovenous fistulas (dAVFs) are similar abnormal connections located within the dura mater. Cavernous malformations (cavernomas) are low-flow lesions composed of sinusoidal vascular spaces that can repeatedly ooze or bleed.

Cerebral Amyloid Angiopathy (CAA)
A common cause of lobar hemorrhage in older, normotensive adults. CAA involves the deposition of amyloid-β protein in the walls of small- to medium-sized cerebral arteries, making them brittle and prone to rupture. Imaging often reveals multiple microhemorrhages in addition to the acute lobar bleed.

Hemorrhagic Neoplasm
Both primary brain tumors (like glioblastoma) and metastatic disease can present with spontaneous hemorrhage. Cancers that commonly bleed include melanoma, renal cell carcinoma, choriocarcinoma, and thyroid cancer. The presence of surrounding edema, enhancement, or multiple lesions should raise suspicion for a tumor.

Ruptured Aneurysm
While saccular (berry) aneurysms typically cause subarachnoid hemorrhage, they can occasionally rupture into the brain parenchyma, causing an intracerebral hematoma, often with an associated subarachnoid component. Mycotic (infectious) aneurysms are a less common but important cause, particularly in patients with endocarditis.

## Why Is MRA Head Without and With IV Contrast Usually Appropriate for This Workup?

When investigating the cause of a proven parenchymal hemorrhage, the ACR designates MRA head without and with IV contrast as a Usually Appropriate study. The rationale is rooted in its ability to comprehensively evaluate the broad differential diagnosis without using ionizing radiation.

The power of this examination comes from combining multiple MRI and MRA techniques into a single study:

  • Standard MRI Sequences (T1, T2, FLAIR): These sequences characterize the hematoma itself, assess for surrounding edema or mass effect, and can reveal signs of an underlying tumor.
  • Susceptibility-Weighted Imaging (SWI) or Gradient-Echo (GRE): These sequences are exquisitely sensitive to blood products. They are critical for identifying the “popcorn” appearance of a cavernous malformation and for detecting the multiple cortical microhemorrhages characteristic of cerebral amyloid angiopathy.
  • Time-of-Flight (TOF) MRA (without contrast): This technique visualizes flowing blood, making it highly effective for detecting aneurysms, AVMs, and the arterialized draining veins of a dAVF.
  • Contrast-Enhanced MRA and MRI: The administration of IV gadolinium contrast helps identify lesions with slower flow, delineates the nidus of an AVM, and can reveal enhancement associated with a tumor or an inflammatory process.

Comparing Alternatives:

  • CTA head with IV contrast is also rated Usually Appropriate. It is an excellent and often faster alternative to MRA for visualizing vascular structures like AVMs and aneurysms. Its primary drawback is the use of ionizing radiation (☢☢☢ 1-10 mSv) and iodinated contrast. It is often the preferred study in unstable patients, those with MRI contraindications (e.g., incompatible implants), or when MRI is not readily available.
  • Arteriography (Digital Subtraction Angiography – DSA) is rated May be Appropriate. While it is the gold standard for vascular detail, it is an invasive procedure that carries a small risk of stroke. It is typically reserved as a problem-solving tool when non-invasive studies are positive or equivocal, or as a precursor to endovascular treatment.

The choice of MRA leverages its superior soft-tissue contrast and sensitivity to blood products of varying ages, providing a more complete diagnostic picture in a single, non-radiative exam. Once you’ve decided on this study, our protocol guide covers the technique, contrast, and reading principles: MRA Brain Without Contrast (3D TOF).

## What’s the Next Step After the MRA Results? Downstream Workflow

The results of the MRA will guide the subsequent clinical pathway. The goal is to move from diagnosis to definitive management and secondary prevention.

  • If the study is POSITIVE for a vascular lesion (AVM, aneurysm, dAVF): The immediate next step is an urgent consultation with neurosurgery and/or neurointerventional radiology. The patient will likely require a conventional digital subtraction angiogram (DSA) to confirm the findings, fully characterize the lesion’s angioarchitecture, and plan for treatment, which may include endovascular embolization, stereotactic radiosurgery, or surgical resection.
  • If the study is NEGATIVE for a vascular lesion:
  • If the hemorrhage location (e.g., basal ganglia, thalamus) and patient history are classic for hypertensive vasculopathy, the focus shifts to aggressive medical management of blood pressure.
  • If the findings are suggestive of cerebral amyloid angiopathy (lobar location, multiple microhemorrhages in an older adult), management is supportive, with strict blood pressure control and avoidance of antithrombotic agents if possible.
  • If the initial MRA/CTA is negative but clinical suspicion for a vascular lesion remains high (e.g., young patient, lobar bleed, associated subarachnoid hemorrhage), a follow-up DSA may still be considered, as it can detect very small lesions missed on non-invasive imaging. A repeat non-invasive study after the hematoma has partially resolved may also be useful.
  • If the study is INDETERMINATE or suggests a tumor: A contrast-enhanced MRI of the brain (if not already performed as part of the initial study) is the next step to better characterize the potential mass. This will likely be followed by a neurosurgical consultation for biopsy or resection.

## Pitfalls to Avoid (and When to Get Help)

Navigating the workup for a parenchymal hemorrhage requires careful consideration to avoid common diagnostic errors.

  • Stopping the Workup Too Early: Do not assume a hemorrhage in a patient with hypertension is automatically due to hypertension, especially if it is in a lobar location. Always consider a secondary cause.
  • Forgetting Susceptibility Sequences: When ordering an MRI/MRA for this indication, ensure that susceptibility-weighted sequences (SWI/GRE) are included in the protocol. They are essential for diagnosing cavernomas and CAA.
  • Misinterpreting a Negative Study: A single negative non-invasive angiogram (CTA or MRA) does not have 100% negative predictive value. In a young patient with a lobar bleed, a follow-up study or conventional angiogram may be necessary.
  • Delaying the Vascular Workup: While the initial focus is on medical stabilization, the vascular imaging workup should be performed promptly, as an underlying lesion like an aneurysm or AVM may be at high risk for imminent re-rupture.

If the imaging reveals a complex vascular malformation or aneurysm, escalate immediately to your local neurosurgery and neurointerventional radiology teams.

## Related ACR Topics and Tools

For a comprehensive overview of imaging for all cerebrovascular disease scenarios, from TIA to suspected stroke, please see our parent guide. The resources below provide direct access to decision support and technical protocols.

Frequently Asked Questions

Why is a non-contrast CT the first study, before the MRA?

A non-contrast head CT is the fastest and most widely available test to confirm the presence of an acute hemorrhage. Its purpose is to make the initial diagnosis rapidly, differentiating a hemorrhagic stroke from an ischemic one. The subsequent MRA or CTA is a more detailed, second-line study designed to determine the underlying cause of the bleed, which is a different clinical question.

If my patient has a pacemaker, can they get an MRA?

It depends on the specific device. Many modern pacemakers and implantable cardioverter-defibrillators (ICDs) are MRI-conditional, meaning they can be safely scanned under specific protocols. This requires coordination with the radiology department and often cardiology to program the device into a safe ‘MRI mode’ for the scan. If the device is not MRI-compatible or the required protocol cannot be met, CTA head with IV contrast is the best alternative.

Is CTA just as good as MRA for this scenario?

CTA head with IV contrast is also rated ‘Usually Appropriate’ and is an excellent study for identifying underlying vascular lesions like aneurysms and AVMs. It is faster than MRA and is preferred in unstable patients or those with MRI contraindications. However, MRA combined with MRI provides superior information about the brain parenchyma, can better characterize cavernous malformations, and is the best test for identifying the microhemorrhages of cerebral amyloid angiopathy, all without using ionizing radiation.

What if the MRA is negative? Is the workup finished?

Not necessarily. If the MRA is negative and the clinical picture is highly suggestive of a hypertensive bleed (e.g., an older patient with poorly controlled hypertension and a deep ganglionic hematoma), then medical management is appropriate. However, in a young, normotensive patient with a lobar hemorrhage, a negative MRA/CTA should prompt consideration of a digital subtraction angiogram (DSA), which is more sensitive for small or subtle vascular lesions.

Does the timing of the MRA after the initial bleed matter?

Yes. The vascular workup should be performed as soon as the patient is medically stable. An underlying aneurysm or AVM carries a high risk of re-bleeding, which is often catastrophic. Delaying the diagnostic imaging delays potential treatment. In some cases where the initial study is negative, a repeat study may be recommended after several weeks, as the resolving hematoma can sometimes unmask a lesion that was previously obscured.

Reviewed by Pouyan Golshani, MD, Interventional Radiologist — May 26, 2026