Computed tomography-negative acute thalamic hematoma

Computed tomography-negative symptomatic intracerebral hemorrhage in a patient with cerebral small vessel disease: A case report

RATIONALE

Computed tomography plays a key role in the initial evaluation of suspected acute stroke by ruling out the possibility of hemorrhage before thrombolysis. Recently, many reports have described cases of symptomatic microbleeds, and there may also have been a case of computed tomography- negative intracerebral hemorrhage.

PATIENT CONCERNS

A 70-year-old female patient who had a history of lacunar infarction and severe small vessel disease developed dysarthria. On brain non-contrast computed tomography there was no evidence of intracerebral hemorrhage. However, brain magnetic resonance imaging performed at 3 hours after the initial computed tomography showed cerebral hemorrhage.

DIAGNOSES

The diagnosis was computed tomography-negative intracerebral hemorrhage.

INTERVENTIONS

The patient was treated with cilostazole 100 mg twice a day with blood pressure management.

OUTCOMES

The dysarthria was fully recovered within 5 days and the patient did not suffer recurrent stroke symptoms over the following 2 years.

LESSONS

In patients with underlying severe small vessel disease and microbleeds, there could be computed tomography-negative hemorrhage and susceptibility weighted magnetic resonance image could be needed. More attention is required before applying thrombolysis therapy because there is a possibility of cerebral hemorrhage in those patients.

Task-driven optimization of the non-spectral mode of photon counting CT for intracranial hemorrhage assessment

Non-contrast CT (NCCT) is widely employed as the first-line imaging test to evaluate intracranial hemorrhage (ICH). Advances in mutidetector CT (MDCT) technology have greatly improved the image quality of NCCT for the detection of established, relatively large, and acute ICHs. Meanwhile, the reliability of MDCT in detecting microbleeds and chronic hemorrhage, and in predicting hemorrhagic transformation needs to be further improved. The purpose of this work was to investigate the potential use of non-spectral photon counting CT (PCCT) to address these challenges in ICH imaging. Towards this goal, the NCCT protocol of an experimental PCCT system that simulates the geometry of a general-purpose MDCT was optimized. The optimization was driven by three imaging tasks: detection of a 4.0 mm intraparenchymal hemorrhage, detection of a 1.5 mm subarachnoid hemorrhage, and discrimination of a sulcus in the insular cortex from the parenchymal background. These imaging tasks were custom-built into an anthropomorphic head phantom. Under the guidance of the frequency-dependent noise equivalent quanta and the ideal observer model detectability index [Formula: see text], the optimal PCD detection mode, energy threshold, and reconstruction kernel were found to be the anti-charge sharing mode, 15 keV, and an apodized ramp kernel, respectively. Compared with a clinical MDCT operated with an ICH protocol and at a matched dose level, the PCCT system provided at least 20% improvements in [Formula: see text] for all three ICH imaging tasks. These results demonstrated the potential benefits of non-spectral PCCT in ICH assessment.