Keiko Kinuya

Thyroid calcifications: Sonographic patterns and incidence of cancer

We investigated the incidence of cancer in surgically resected 151 thyroid nodules in 101 patients according to their calcification patterns on preoperative ultrasonography (US). Calcification was detected in 57 (38%) nodules, 31 (54%) of which was histologically diagnosed as cancer. According to the calcification types, 9 of 11 nodules with microcalcifications, 15 of 29 nodules with intranodular coarse calcification, 6 of 14 nodules with peripheral calcification and 1 of 3 calcified spots without surrounding tumor were diagnosed as cancer.

SPECT evaluation of brain perfusion reserve by the acetazolamide test using Tc-99m HMPAO.

This report describes a new approach to the evaluation of brain perfusion reserve using Tc-99m HMPAO SPECT. Consecutive brain Tc-99m HMPAO SPECT studies before and after acetazolamide (Diamox) administration were performed within 30 minutes on 19 patients with significant vascular occlusive lesions. Thirteen patients showed decreased perfusion reserve and four patients maintained perfusion reserve in the affected vascular territories after Diamox administration, providing additional information to baseline Tc-99m HMPAO SPECT in 17 (89%) patients. Although flow augmentation post-Diamox was underestimated, possibly due to the nonproportionality of Tc-99m HMPAO activity to true blood flow, significant changes in the brain perfusion pattern were both visually and quantitatively determined using an image subtraction technique. This consecutive Tc-99m HMPAO SPECT technique seems to be of practical use for the evaluation of brain perfusion reserve and for the improvement of the sensitivity of detecting pathologic areas.

Role of brain perfusion single-photon emission tomography in traumatic head injury.

This investigation examined the role of brain perfusion single-photon emission tomography (SPET) in traumatic head injury in 35 patients. The results were compared with those of X-ray computerized tomography (CT) and magnetic resonance imaging (MRI). CT and MRI detected brain contusions in seven patients, subarachnoid haemorrhage in one patient and both in nine patients. In 16 of the 17 subjects (94%), SPET with technetium-99m-hexamethylpropyleneamine oxime (99mTc-HMPAO) revealed CT/MRI-negative abnormalities, such as hypoperfusion in the contre-coup region, frontal hypoperfusion related to personality change and cerebellar hypoperfusion associated with vertigo. In two patients presenting with diffuse axonal injury in the brainstem, hypoperfusion in the frontal cortex on the affected side was observed on SPET. SPET demonstrated hypoperfusion in the adjacent cortex, with no abnormality on either CT or MRI, in six of seven patients exhibiting acute epidural haematoma. SPET failed to provide additional information in two of five patients with acute subdural haematoma and in one of two patients displaying chronic subdural haematoma. In four of nine patients with post-traumatic amnesia, SPET detected hypoperfusion in the temporal lobe, with no abnormality on either CT or MRI. In five of eight patients with vertigo, SPET detected hypoperfusion in the morphologically normal cerebellum. In seven cases involving personality change, frontal hypoperfusion was observed in four; moreover, a markedly non-homogeneous pattern was evident in the remaining three. Overall, SPET afforded additional information in 26 patients (74%). CT possesses an advantage with respect to the detection of haemorrhagic lesions. MRI provides more precise information regarding contusions and axonal injury. Frequently, SPET may be the only examination to reveal perfusion abnormalities which are related to symptoms in the absence of other objective findings, such as post-traumatic amnesia, vertigo or personality change.

Esophageal hypomotility in systemic sclerosis: close relationship with pulmonary involvement.

Purpose: Esophageal motility was assessed in patients with systemic selerosis (SSc) by scintigraphy and compared with (i) extent of scleroderma, (ii) duration of disease, (iii) index of antitopoisomerase I antibody (topo I), and (iv) pulmonary involvement.Methods: A multiple-swallow test was performed in 47 patients with SSc in the supine position with99mTc-DTPA. A region of interest on the entire esophagus was defined and the retention ratio (RR) was calculated from a time-activity curve.Results: Patients with diffuse scleroderma had higher RRs than those with limited scleroderma (48.8% vs. 30.0%; p<0.05). There was no correlation between the RRs and the duration of disease. Patients with positive topo I had higher RRs than those who were negative (53.8% vs. 29.7%; p<0.05). Patients with reduced % diffusion capacity for carbon monoxide (%DLCO) had higher RRs thans those with normal %DLCO (40.5% vs. 19.6%; p=0.03). Patients with reduced % vital capacity (%VC) had higher RRs than those with normal % VC (54.6% vs. 25.0%; p<0.005). Patients with pulmonary fibrosis had higher RRs than those who were negative (58.5% vs. 20.3%; p<0.00005).Conclusion: Esophageal dysfunction in patients with SSc showed a correlation with the extent of scleroderma, positive topo I, and pulmonary involvement. The RR can be an objective clinical marker for the severity of organ fibrosis.

Acetazolamide effect on vascular response in areas with diaschisis as measured by Tc-99m HMPAO brain SPECT.

The effects of acetazolamide (Diamox®) on vascular response were investigated in areas with intrahemispheric thalamic diaschisis and crossed cerebellar diaschisis using consecutive Tc-99m HMPAO brain SPECT studies before and after Diamox administration. All six patients with thalamic diaschisis and five of eight patients with crossed cerebellar diaschisis at baseline showed significantly augmented perfusion after Diamox administration in the affected thalamus and cerebellum compared with that in the contralateral unaffected areas. These results suggest more dilatation of the arterioles in areas with diaschisis after Diamox administration than in areas without diaschisis. Diamox may produce relative luxury perfusion in areas with diaschisis.

Intense Ga-67 uptake in adenosquamous carcinoma of the pancreas

Gallium-67 citrate (Ga-67) scintigraphy was performed in a patient with adenosquamous carcinoma of the pancreas. Intense and homogeneous uptake was observed in the tumor. Few reports have dealt with Ga-67 findings in pancreatic cancers. Ga-67 uptake in the tumor was assumed to be due to accumulation in the component of squamous cell carcinoma. This case suggested that Ga-67 citrate scintigraphy may be useful in detecting adenosquamous carcinoma of the pancreas. To our knowledge, no report has described findings of Ga-67 citrate scintigraphy of adenosquamous carcinoma of the pancreas. Radiologists should remember adenosquamous carcinoma of the pancreas when encountering such scintigraphic findings.

Synthesis of radioiodinated analogs of 2-(4-Phenylpiperidino)cyclohexanol (vesamicol) as vesamicol-like agent

Three iodovesamicol analogs, iodinated at the ortho, meta, and para positions of the 4-phenylpiperidine moiety, were synthesized and labeled with 125I by isotopic exchange reaction. Their potencies as a vesamicol-like drug were evaluated with competitive inhibition studies using (-)[3H]vesamicol. The radiochemical yields were 40-85%, the radiochemical purities exceeded 95% and their specific activities were 370-740 GBq/mmol. The descending order of binding affinity of the tested compounds against the vesamicol receptor was m-iodovesamicol > o-iodovesamicol > p-iodovesamicol. The receptor binding affinity of m-iodovesamicol (IC50 = 133 nM) was comparable with that of vesamicol (IC50 = 109 nM). Therefore, the meta position of the 4-phenylpiperidinyl fragment of vesamicol was the optimum site for iodination, and radioiodinated m-iodovesamicol may serve as a useful radiopharmaceutical for in vitro and in vivo studies of presynaptic cholinergic neurons in rats.

The diagnostic value of oesophageal transit scintigraphy for evaluating the severity of oesophageal complications in systemic sclerosis.

BackgroundOesophageal complications are common in systemic sclerosis (SSc). However, the ability to determine the severity of oesophageal complications according to SSc type and skin lesion has not been evaluated. MethodsThe study groups consisted of 35 patients with SSc who were classified into diffuse (n=20) and limited (n=15) cutaneous types, and 16 control subjects. An additional 26 consecutive patients were studied for an analysis of the reproducibility. The severity of a skin lesion was quantified by using a modification of Rodnans total skin thickness scores. Oesophageal scans were performed after the subjects, in sitting and supine positions, had consumed potage soup. Condensed images of the dynamic study were classified into four patterns: normal, transient retention, slight retention and severe retention, in conjunction with parameters of retention fraction by analysing the time–activity curve. ResultsThe highest reproducibility was obtained using retention at 90 s (R90, r=0.93). Analysis of the condensed images showed that the SSc patients had a higher incidence of severe retention than did the control subjects. Groups with diffuse-type SSc or a high skin thickness score showed a higher incidence of severe retention (P=0.041 and 0.0048, respectively) compared with the control and less severe groups. The R90 in the supine position differed significantly among the controls, the limited-type and diffuse-type SSc groups (mean±SEM, 10±1%, 24±5%, 38±6%, respectively; P=0.0004)). The group with high skin scores (i.e. ≥10) showed a higher R90 (41±6%) than did either the group with low skin scores (R90=23±5%) or the control group (P=0.0001). ConclusionAn oesophageal scan can detect both slight and severe types of oesophageal dysfunction, and can be used as a quantitative method that reflects functional abnormality in SSc.

Tc-99m HMPAO brain perfusion tomography atlas using a high resolution SPECT system.

Excellent SPECT images of brain perfusion with Tc-99m HMPAO were obtained by the use of a three-head rotating gamma camera SPECT system with high resolution (FWHM 7mm) in a normal volunteer. These images should be clinically effective for evaluating various neurologic disorders. Transverse, coronal, and sagittal sectional HMPAO-SPECT images are correlated with corresponding brain MRI images of the same normal volunteer in this atlas.

Simple scintigraphic parameters with Tc-99m galactosyl human serum albumin for clinical staging of chronic hepatocellular dysfunction

Technetium-99m labeled diethylenetriaminepentaacetic acid (DTPA)-galactosyl human serum albumin (GSA) has been used for hepatocellular functional evaluation. This study proposed new and simple parameters to overcome the limitations of conventional parameters, and they were applied to the clinical staging of chronic liver dysfunction. The study group consisted of 93 patients including 81 with liver dysfunction and 12 control patients. In addition to the two conventional parameters, namely, receptor index (LHL15 = liver count divided by the sum of liver and heart counts at 15 minutes) and clearance index (HH15 = heart count at 15 minutes divided by the heart count at 3 minutes), 6 new parameters for Tc-99m GSA uptake and clearance were generated. The conventional receptor index of LHL15 showed a large variation depending on the size of region of interest (ROI) over the heart. The LHL15 normalized by the ROI size (nLHL15) showed more stable data and a better separation of mild liver dysfunction. A hyperbolic relationship between the LHL15 and HH15 changed to a linear relationship by using the nLHL15 index. The combination of the liver to heart average count ratio at 15 minutes (LH15) and T-half (minute) of the heart count also could differentiate each stage well. In conclusion, the use of the ROI-area normalized nLHL is recommended instead of the conventional LHL15. The indices of LH15 and T-half could be alternatively used as practical parameters for clinical staging in liver function.