Journal of Clinical Neuroscience 21 (2014) 745–750
Contents lists available at ScienceDirect
Journal of Clinical Neuroscience journal homepage: www.elsevier.com/locate/jocn
Clinical Study
Comparative evaluation of MRS and SPECT in prognostication of patients with mild to moderate head injury Sivashanmugam Dhandapani ⇑, Anurag Sharma, Karamchand Sharma, Lakshman Das Departments of Neurosurgery, Safdarjung Hospital, New Delhi and PGIMER, Chandigarh, India
a r t i c l e
i n f o
Article history: Received 24 April 2013 Accepted 4 July 2013
Keywords: Head injury Hypoperfusion MRS NAA/Cr ratio Outcome SPECT
a b s t r a c t Magnetic resonance spectroscopy (MRS) and single-photon emission computed tomography (SPECT) have only been individually studied in patients with head injury. This study aimed to comparatively assess both in patients with mild to moderate head injury. Patients with a Glasgow Coma Scale (GCS) score of 9–14 who underwent MRS and/or SPECT were evaluated in relation to various clinical factors and neurological outcome at 3 months. There were 56 SPECT (Tc99m-ethylcysteinate dimer [ECD]) studies and 41 single voxel proton MRS performed in 53 patients, with 41 patients having both. Of the 41 who underwent MRS, 13 had a lower N-acetyl-aspartate/creatine (NAA/Cr) ratio, 14 had a higher choline (Cho)/Cr ratio, 19 were normal, and nine had bilateral MRS abnormalities. Of the 56 who underwent SPECT, 22 and 19 had severe and moderate hypoperfusion, respectively. Among those in Traumatic Coma Data Bank CT scan category 1 and 2, 50% had MRS abnormalities, whereas 64% had SPECT hypoperfusion, suggesting greater incremental validity of SPECT over MRS. In univariate analyses, GCS, moderate/severe hypoperfusion and bilateral SPECT changes were found to have significant association with unfavorable outcome (odds ratio 13.2, 15.9, and 4.4, and p values 1.5), 14 had higher than normal Cho/Cr ratio (normal < 1.2), 19 were normal, and nine had bilateral abnormalities (Fig. 3A). Lower NAA/Cr ratios were noted more after 2 weeks of injury (67%), and higher Cho/Cr ratios were found between 1–3 days after injury (45%) (non-significant) (Table 1). Among the 56 SPECT studies, 10 were performed on the day of traumatic head injury (day 0), 24 were performed on day 1–3, 11 on day 3–14 and 11 were performed on day 15–21. Out of the 56 SPECT studies, 22 had severe hypoperfusion, 19 had moderate hypoperfusion, 11 had mild hypoperfusion and four were normal (Fig. 3B). All patients who underwent SPECT within 24 hours of injury were found to have moderate to severe hypoperfusion (p = 0.05) (Table 1). Hypoperfusion was most common in the frontal lobes (n = 36) followed by the temporal lobes (n = 34), and parietal lobes (n = 25). Of the three patients who had repeat SPECT, one had improved and two were unchanged after 1 week. There was a non-significant association between SPECT and MRS findings (Table 2). Lower NAA/Cr ratios on MRS were noted to be directly proportional to the severity of hypoperfusion seen on SPECT. Lower NAA/Cr ratios on MRS were reported in 14% of patients with normal to mild hypoperfusion on SPECT compared to 50% of those with severe hypoperfusion on SPECT.
Fig. 1. (A) Normal magnetic resonance spectroscopy (MRS), and (B) abnormal MRS showing an N-acetyl-aspartate/creatine ratio 1.2.
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Fig. 2. A patient with (A) normal CT, but (B) moderate hypoperfusion in SPECT, demonstrating incremental validity of SPECT over CT.
Fig. 3. Pie graph showing (A) the distribution of magnetic resonance spectroscopy findings, and (B) the distribution of single-photon emission computed tomography findings. Cho = choline, cr = creatine, NAA = N-acetyl-aspartate, " = higher than normal, ; = lower than normal.
Table 1 Timing and findings of magnetic resonance spectroscopy and single-photon emission computed tomography in patients with mild-to-moderate head injury
Contents lists available at ScienceDirect
Journal of Clinical Neuroscience journal homepage: www.elsevier.com/locate/jocn
Clinical Study
Comparative evaluation of MRS and SPECT in prognostication of patients with mild to moderate head injury Sivashanmugam Dhandapani ⇑, Anurag Sharma, Karamchand Sharma, Lakshman Das Departments of Neurosurgery, Safdarjung Hospital, New Delhi and PGIMER, Chandigarh, India
a r t i c l e
i n f o
Article history: Received 24 April 2013 Accepted 4 July 2013
Keywords: Head injury Hypoperfusion MRS NAA/Cr ratio Outcome SPECT
a b s t r a c t Magnetic resonance spectroscopy (MRS) and single-photon emission computed tomography (SPECT) have only been individually studied in patients with head injury. This study aimed to comparatively assess both in patients with mild to moderate head injury. Patients with a Glasgow Coma Scale (GCS) score of 9–14 who underwent MRS and/or SPECT were evaluated in relation to various clinical factors and neurological outcome at 3 months. There were 56 SPECT (Tc99m-ethylcysteinate dimer [ECD]) studies and 41 single voxel proton MRS performed in 53 patients, with 41 patients having both. Of the 41 who underwent MRS, 13 had a lower N-acetyl-aspartate/creatine (NAA/Cr) ratio, 14 had a higher choline (Cho)/Cr ratio, 19 were normal, and nine had bilateral MRS abnormalities. Of the 56 who underwent SPECT, 22 and 19 had severe and moderate hypoperfusion, respectively. Among those in Traumatic Coma Data Bank CT scan category 1 and 2, 50% had MRS abnormalities, whereas 64% had SPECT hypoperfusion, suggesting greater incremental validity of SPECT over MRS. In univariate analyses, GCS, moderate/severe hypoperfusion and bilateral SPECT changes were found to have significant association with unfavorable outcome (odds ratio 13.2, 15.9, and 4.4, and p values 1.5), 14 had higher than normal Cho/Cr ratio (normal < 1.2), 19 were normal, and nine had bilateral abnormalities (Fig. 3A). Lower NAA/Cr ratios were noted more after 2 weeks of injury (67%), and higher Cho/Cr ratios were found between 1–3 days after injury (45%) (non-significant) (Table 1). Among the 56 SPECT studies, 10 were performed on the day of traumatic head injury (day 0), 24 were performed on day 1–3, 11 on day 3–14 and 11 were performed on day 15–21. Out of the 56 SPECT studies, 22 had severe hypoperfusion, 19 had moderate hypoperfusion, 11 had mild hypoperfusion and four were normal (Fig. 3B). All patients who underwent SPECT within 24 hours of injury were found to have moderate to severe hypoperfusion (p = 0.05) (Table 1). Hypoperfusion was most common in the frontal lobes (n = 36) followed by the temporal lobes (n = 34), and parietal lobes (n = 25). Of the three patients who had repeat SPECT, one had improved and two were unchanged after 1 week. There was a non-significant association between SPECT and MRS findings (Table 2). Lower NAA/Cr ratios on MRS were noted to be directly proportional to the severity of hypoperfusion seen on SPECT. Lower NAA/Cr ratios on MRS were reported in 14% of patients with normal to mild hypoperfusion on SPECT compared to 50% of those with severe hypoperfusion on SPECT.
Fig. 1. (A) Normal magnetic resonance spectroscopy (MRS), and (B) abnormal MRS showing an N-acetyl-aspartate/creatine ratio 1.2.
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Fig. 2. A patient with (A) normal CT, but (B) moderate hypoperfusion in SPECT, demonstrating incremental validity of SPECT over CT.
Fig. 3. Pie graph showing (A) the distribution of magnetic resonance spectroscopy findings, and (B) the distribution of single-photon emission computed tomography findings. Cho = choline, cr = creatine, NAA = N-acetyl-aspartate, " = higher than normal, ; = lower than normal.
Table 1 Timing and findings of magnetic resonance spectroscopy and single-photon emission computed tomography in patients with mild-to-moderate head injury
