2025年2月14日 · Subarachnoid hemorrhages are grouped into four categories according to the amount of blood on unenhanced CT by the Fisher scale. This scale has been updated to the modified Fisher scale , which more accurately correlates the risk of vasospasm.

2016年7月23日 · CT scan remains by far the most widely applied technique. Its sensitivity for the acute diagnosis of SAH exceeds 95%. 11 However, CT scan is most reliable early after the bleeding (particularly within the first 24–48 hours) and false-negative results become possible after a few days.

performance of noncontrast CT scan for SAH diagnosis. Noncontrast CT is the standard initial test for possible subarachnoid hemorrhage. The sensitivity is nearly 100% within six hours of headache onset, after which time blood starts looking a bit more grey, so the sensitivity may decrease slightly.

2011年9月15日 · This article attempts to make the argument that with the development of advanced generation CT machines, head CT is sensitive enough to detect all cases of SAH, and follow-up lumbar puncture...

It has been suggested that a negative non-contrast CT head can rule out SAH if performed within 6 h of symptom onset. What is the sensitivity of CT head at ruling out SAH stratified by time-point, and what is the potential impact of omitting Lumbar Puncture (LP) from the diagnostic pathway?

2025年2月14日 · The sensitivity of non-contrast CT to the presence of subarachnoid blood is strongly influenced by both the amount of blood and the time since the haemorrhage. The diagnosis is suspected when a hyperdense material is seen filling the subarachnoid space.

Computed Tomography (CT) is the accepted first line investigation for patients with a suspected subarachnoid haemorrhage (SAH). SAH is associated with a normal CT in up to 2#x0025; of cases within 12 hours of onset of symptoms, [1] 6.9% within 24 hours [2] …

2023年2月2日 · Spontaneous subarachnoid hemorrhage (SAH) is a can’t miss diagnosis for patients presenting to the emergency department with a headache. The diagnosis is associated with a 30% mortality at 30 days, and approximately 30% of survivors may have long-term neurocognitive deficits (Rincon et al., 2013).

2012年7月19日 · Although CT is an excellent test for SAH, its sensitivity is both a function of timing from the onset of the headache as well as severity of the hemorrhage. 1 CT sensitivity is extremely high early but rapidly diminishes with time. Clinicians frequently encounter neurologically normal patients with a thunderclap headache and a negative CT scan.

2018年4月2日 · non-contrast CT head or initial assessment; if signs of subarachnoid hemorrhage, CT angiogram; lumbar puncture (looking for xanthochromia >12 h after symptoms) treatment. depends on the cause but there are general principles. high fluid intake (>3500 mL/day) to prevent vasospasm;