The ABCs of Measuring Intracerebral Hemorrhage Volumes


Background and Purpose Hemorrhage volume is a powerful predictor of 30-day mortality after spontaneous intracerebral hemorrhage (ICH). We compared a bedside method of measuring CT ICH volume with measurements made by computer-assisted planimetric image analysis.

Methods The formula ABC/2 was used, where A is the greatest hemorrhage diameter by CT, B is the diameter 90° to A, and C is the approximate number of CT slices with hemorrhage multiplied by the slice thickness.

Results The ICH volumes for 118 patients were evaluated in a mean of 38 seconds and correlated with planimetric measurements (R2=.96). Interrater and intrarater reliability were excellent, with an intraclass correlation of .99 for both.

Conclusions We conclude that ICH volume can be accurately estimated in less than 1 minute with the simple formula ABC/2.


  • Introduction

The 30-day mortality rate of intracerebral hemorrhage (ICH) is approximately 44%, with almost half of the patients dying within the first 48 hours.1 There is no proven effective treatment, and the ability to rapidly determine a patient’s prognosis at the bedside would be a powerful tool in selecting and stratifying patients in future trials of surgical intervention. Hemorrhage volume, level of consciousness, and the presence of intraventricular extension have all been documented as predictors of ICH outcome.2 The latter two can be easily evaluated. We compare a bedside method of ICH volume measurement3 with a computerized planimetric measurement.

Subjects and Methods

One hundred eighteen patients with spontaneous ICH were assessed prospectively with CT within 3 hours of symptom onset. Exclusion criteria included (1) CT evidence of a subarachnoid hemorrhage, (2) history of recent trauma, (3) isolated intraventricular hemorrhage, and (4) ICH due to aneurysm or arteriovenous malformation. Hemorrhage volumes were measured by a computerized planimetric method and a simplified formula for the volume of an ellipsoid, ABC/2 (see “Appendix”). Measurement by planimetrics is an established and accurate method of measuring ICH volume that uses computer-assisted image analysis.2 4 5

For the bedside ABC/2 method, the CT slice with the largest area of hemorrhage was identified. The largest diameter (A) of the hemorrhage on this slice was measured. The largest diameter 90° to A on the same slice was measured next (B). Finally, the approximate number of 10-mm slices on which the ICH was seen was calculated (C). C was calculated by a comparison of each CT slice with hemorrhage to the CT slice with the largest hemorrhage on that scan. If the hemorrhage area for a particular slice was greater than 75% of the area seen on the slice where the hemorrhage was largest, the slice was considered 1 hemorrhage slice for determining C. If the area was approximately 25% to 75% of the area, the slice was considered half a hemorrhage slice; and if the area was less than 25% of the largest hemorrhage, the slice was not considered a hemorrhage slice. These CT hemorrhage slice values were then added to determine the value for C. All measurements for A and B were made with the use of the centimeter scale on the CT scan to the nearest 0.5 cm. A, B, and C were then multiplied and the product divided by 2, which yielded the volume of hemorrhage in cubic centimeters. The time required for the measurements and calculations was recorded. Hemorrhage volumes determined by the two techniques were then compared by regression analysis.

Twenty CT scans were randomly selected from the study population of 118, and hemorrhage volumes were measured by four individuals (a neurosurgery faculty member [M.Z.], a third-year neurosurgery resident, an emergency medicine faculty member [R.U.K], and a registered nurse [L.R.S.]) with the ABC/2 technique.

We evaluated intrarater reliability for a single reader by comparing initial measurements of these 20 CT scans using the ABC/2 method with repeated measurements by the same investigator using the same technique.


Of the 118 patients evaluated, 83 (70%) were deep hemorrhages, 21 (18%) were lobar, 8 (7%) were brain stem, and 6 (5%) were cerebellar. The correlation between measurements by planimetric and ABC/2 methods was very high (R2=.96). Measurements by a single reader using the ABC/2 method correlated well with planimetric measurements for all hemorrhage locations (Table 1). The ABC/2 method overestimated hemorrhage volume by 1.5±1.3 cm3. The ABC/2 method required a mean time of 38 seconds (range, 70 to 210 seconds). In the subset of 20 CT scans measured by four different readers, we noted excellent interrater (intraclass correlation=.99) and intrarater (intraclass correlation=.99) reliability when the ABC/2 technique was used (Table 2). The mean time per measurement for the readers ranged from 31 to 40 seconds.

Reliability and Reproducibility of the ABC/2 Method of Measuring Intraparenchymal Hemorrhage Volume


A number of techniques have been developed to measure hemorrhage volume.2 6 7 8 Unfortunately, these methods often involve complicated formulas, require specialized equipment, or cannot be performed rapidly at the patient’s bedside. We found that the simple formula ABC/2 can accurately estimate intraparenchymal hemorrhage volume and requires less than 1 minute for measurement and calculation. The measurements correlate highly with the volumes calculated by planimetric methods for all hemorrhage locations.

Rapid calculation of ICH volume at the time of initial patient presentation has clinical utility. For prognosis, a model of 30-day mortality that used the Glasgow Coma Scale and hemorrhage volume in patients with ICH correctly predicted outcome with a sensitivity and specificity of 97%.2 The ABC/2 technique may also be used to identify appropriate patients with ICH suitable for randomization into therapeutic trials.3 For example, the technique is the measurement method used for patient eligibility assessment in the multicenter Surgical Trial of Intracerebral Hemorrhage (J. Grotta, unpublished data, 1996). In this trial, patients with ICH and anticipated good outcome are not eligible for surgery. Thus, patients with hemorrhage volumes of less than 10 cm3 and patients with lobar hemorrhage volumes of 10 to 20 cm3 with minimal or no neurological deficits are excluded.

The ABC/2 and other bedside techniques of calculating hemorrhage volumes have been described previously.3 5 6 Lisk and colleagues3 demonstrated the ease and power of theABC/2 method of volume measurement in a model of outcome after ICH but did not correlate this technique with other methods of volume measurement. The ABC/2 formula can be adjusted for CT slices of varying thickness by multiplying the number of slices of the different thicknesses on which the hematoma is seen (C of ABC/2) by the slice thickness in centimeters. Other authors have estimated hematoma volume by assuming it to approximate the volume of a sphere, an ellipsoid, or a rectangulopiped.2 7 8 Only estimates of volume that use the formula for an ellipsoid have been shown to correlate with planimetric techniques.5

In conclusion, intraparenchymal hemorrhage volume can be accurately estimated in less than 1 minute with the simple formula ABC/2. This rapid method of measuring hemorrhage volume may allow physicians to quickly select and stratify patients in future treatment trials.


The derivation of the ABC/2 formula is as follows: The volume of an ellipsoid is 4/3π(A/2)(B/2)(C/2), where A, B, and C are the three diameters. If π is estimated to be 3, then the volume of an ellipsoid becomes ABC/2.


  • Reprint requests to Rashmi Kothari, MD, Department of Emergency Medicine, University of Cincinnati College of Medicine, PO Box 670769, Cincinnati, OH 45267-0769.

  • Received December 28, 1995.
  • Revision received April 17, 1996.
  • Accepted April 17, 1996.


Impact of global cerebral atrophy on clinical outcome after subarachnoid hemorrhage.



Atrophy in specific brain areas correlates with poor neuropsychological outcome after subarachnoid hemorrhage (SAH). Few studies have compared global atrophy in SAH with outcome. The authors examined the relationship between global brain atrophy, clinical factors, and outcome after SAH.


This study was a post hoc exploratory analysis of the Clazosentan to Overcome Neurological Ischemia and Infarction Occurring After Subarachnoid Hemorrhage (CONSCIOUS-1) trial, a randomized, double-blind, placebo-controlled trial of 413 patients with aneurysmal SAH. Patients with infarctions or areas of encephalomalacia on CT, and those with large clip/coil artifacts, were excluded. The 97 remaining patients underwent CT at baseline and 6 weeks, which was analyzed using voxel-based volumetric measurements. The percentage difference in volume between time points was compared against clinical variables. The relationship with clinical outcome was modeled using univariate and multivariate analysis.


Older age, male sex, and systemic inflammatory response syndrome (SIRS) during intensive care stay were significantly associated with brain atrophy. Greater brain atrophy was significantly associated with poor outcome on the modified Rankin scale (mRS), severity of deficits on the National Institutes of Health Stroke Scale (NIHSS), worse executive functioning, and lower EuroQol Group–5D (EQ-5D) score. Adjusted for confounders, brain atrophy was not significantly associated with Mini-Mental State Examination and Functional Status Examination scores. Brain atrophy was not associated with angiographic vasospasm or delayed ischemic neurological deficit.


Worse mRS score, NIHSS score, executive functioning, and EQ-5D scores were associated with greater brain atrophy and older age, male sex, and SIRS burden. These data suggest outcome is associated with factors that cause global brain injury independent of focal brain injury.

Source: JNS



Volumetric analysis of subarachnoid hemorrhage: assessment of the reliability of two computerized methods and their comparison with other radiographic scales.


There were two main purposes to this study: first, to assess the feasibility and reliability of 2 quantitative methods to assess bleeding volume in patients who suffered spontaneous subarachnoid hemorrhage (SAH), and second, to compare these methods to other qualitative and semiquantitative scales in terms of reliability and accuracy in predicting delayed cerebral ischemia (DCI) and outcome.


A prospective series of 150 patients consecutively admitted to the Hospital 12 de Octubre over a 4-year period were included in the study. All of these patients had a diagnosis of SAH, and diagnostic CT was able to be performed in the first 24 hours after the onset of the symptoms. All CT scans were evaluated by 2 independent observers in a blinded fashion, using 2 different quantitative methods to estimate the aneurysmal bleeding volume: region of interest (ROI) volume and the Cavalieri method. The images were also graded using the Fisher scale, modified Fisher scale, Claasen scale, and the semiquantitative Hijdra scale. Weighted κ coefficients were calculated for assessing the interobserver reliability of qualitative scales and the Hijdra scores. For assessing the intermethod and interrater reliability of volumetric measurements, intraclass correlation coefficients (ICCs) were used as well as the methodology proposed by Bland and Altman. Finally, weighted κ coefficients were calculated for the different quartiles of the volumetric measurements to make comparison with qualitative scales easier. Patients surviving more than 48 hours were included in the analysis of DCI predisposing factors and analyzed using the chi-square or the Mann-Whitney U-tests. Logistic regression analysis was used for predicting DCI and outcome in the different quartiles of bleeding volume to obtain adjusted ORs. The diagnostic accuracy of each scale was obtained by calculating the area under the receiver operating characteristic curve (AUC).


Qualitative scores showed a moderate interobserver reproducibility (weighted κ indexes were always < 0.65), whereas the semiquantitative and quantitative scores had a very strong interobserver reproducibility. Reliability was very high for all quantitative measures as expressed by the ICCs for intermethod and interobserver agreement. Poor outcome and DCI occurred in 49% and 31% of patients, respectively. Larger bleeding volumes were related to a poorer outcome and a higher risk of developing DCI, and the proportion of patients suffering DCI or a poor outcome increased with each quartile, maintaining this relationship after adjusting for the main clinical factors related to outcome. Quantitative analysis of total bleeding volume achieved the highest AUC, and had a greater discriminative ability than the qualitative scales for predicting the development of DCI and outcome.


The use of quantitative measures may reduce interobserver variability in comparison with categorical scales. These measures are feasible using dedicated software and show a better prognostic capability in relation to outcome and DCI than conventional categorical scales.

Source: Journal of neurosurgery.



Oculomotor nerve palsy by posterior communicating artery aneurysms: influence of surgical strategy on recovery.

Resolution of oculomotor nerve palsy (ONP) after clipping of posterior communicating artery (PCoA) aneurysms has been well documented. However, whether additional decompression of the oculomotor nerve via aneurysm sac dissection or resection is superior to pure aneurysm clipping is the subject of much debate. Therefore, the objective in the present investigation was to analyze the influence of surgical strategy—specifically, clipping with or without aneurysm dissection—on ONP resolution.


Between June 1999 and December 2010, 18 consecutive patients with ruptured and unruptured PCoA aneurysms causing ONP were treated at the authors’ institution. Oculomotor nerve palsy was evaluated on admission and at follow-up. The electronic database MEDLINE was searched for additional data in published studies of PCoA aneurysms causing ONP. Two reviewers independently extracted data.


Overall, 8 studies from the literature review and 6 patients in the current series (121 PCoA aneurysms) met the study inclusion criteria. Ninety-four aneurysms were treated with simple aneurysm neck clipping and 27 with clipping plus aneurysm sac decompression. The surgical strategy, simple aneurysm neck clipping versus clipping plus oculomotor nerve decompression, had no effect on full ONP resolution on univariate (p = 0.5) and multivariate analyses. On multivariate analysis, patients with incomplete ONP at admission were more likely to have full resolution of the palsy than were those with complete ONP at admission (p = 0.03, OR = 4.2, 95% CI 1.1–16).


Data in the present study indicated that ONP caused by PCoA aneurysms improves after clipping without and with oculomotor nerve decompression. The resolution of ONP is inversely associated with the initial severity of ONP.

Source: Journal Of Neurosurgery.




Timing of clinical grade assessment and poor outcome in patients with aneurysmal subarachnoid hemorrhage.

Timing of clinical grading has not been fully studied in patients with aneurysmal subarachnoid hemorrhage (SAH). The primary objective of this study was to identify at which time point clinical assessment using the World Federation of Neurosurgical Societies (WFNS) grading scale and the Glasgow Coma Scale (GCS) is most predictive of poor functional outcome.


This study is a retrospective cohort study on the association between poor outcome and clinical grading determined at presentation, nadir, and postresuscitation. Poor functional outcome was defined as a Glasgow Outcome Scale score of 1–3 at 6 months after SAH.


The authors identified 186 consecutive patients admitted to a teaching hospital between January 2002 and June 2008. The patients’ mean age (± SD) was 56.9 ± 13.7 years, and 63% were women. Twenty-four percent had poor functional outcome (the mortality rate was 17%). On univariable logistic regression analyses, GCS score determined at presentation (OR 0.80, p < 0.0001), nadir (OR 0.73, p < 0.0001), and postresuscitation (OR 0.53, p < 0.0001); modified Fisher scale (OR 2.21, p = 0.0013); WFNS grade assessed at presentation (OR 1.92, p < 0.0001), nadir (OR 3.51, < 0.0001), and postresuscitation (OR 3.91, p < 0.0001); intracerebral hematoma on initial CT (OR 4.55, p < 0.0002); acute hydrocephalus (OR 2.29, p = 0.0375); and cerebral infarction (OR 4.84, p < 0.0001) were associated with poor outcome. On multivariable logistic regression analysis, only cerebral infarction (OR 5.80, p = 0.0013) and WFNS grade postresuscitation (OR 3.43, p < 0.0001) were associated with poor outcome. Receiver operating characteristic/area under the curve (AUC) analysis demonstrated that WFNS grade determined postresuscitation had a stronger association with poor outcome (AUC 0.90) than WFNS grade assessed upon admission or at nadir.


Timing of WFNS grade assessment affects its prognostic value. Outcome after aneurysmal SAH is best predicted by assessing WFNS grade after neurological resuscitation.

Source: Journal of neurosurgery.