Tc-99m MAA SPECT in pectus excavatum: assessment of perfusion volume changes after correction by the Nuss procedure.

PURPOSE: The Nuss procedure is a minimally invasive technique for the repair of pectus excavatum. This investigation attempted to assess the impact of this corrective protocol on pulmonary functional volume through analysis of distribution volume data derived from Tc-99m MAA SPECT. MATERIAL AND METHODS: SPECT was performed in 3 patients before and 6 months after completion of the Nuss procedure. Before the clinical application of SPECT, phantom experiments were conducted to establish the threshold level based on the volume calculation program. Haller's index, a quantitative index of chest-wall deformity, was also obtained by x-ray CT. RESULTS: A threshold level of 30% was the most accurate determinant of pulmonary volume. Preoperative and postoperative Tc-99m MAA distribution volumes (MAA volume in mL) were 2812 and 3107 (an increase of 10%), 2212 and 2410 (9%), and 2341 and 2872 (23%), respectively. In all patients, MAA volume increased after corrective intervention. Changes were most striking in the left lung, which is affected to a greater extent by dislocation of the heart. Morphologic improvement in the lungs was also demonstrated by Haller's CT index in all patients, which decreased from 4.35, 3.52, and 10.67, preoperatively, to 3.45, 2.75, and 4.25, respectively, postoperatively. CONCLUSION: MAA volume assessment is an easy, suitable approach for detection of favorable changes produced by the Nuss procedure in pectus excavatum.

Sonographically guided core biopsy of the salivary gland masses: safety and efficacy.

Over an 8-year period, we performed ultrasonography (US)-guided core biopsy of the salivary gland in 37 patients using an 1l-mm-throw 18-gauge automated biopsy system. The biopsy results were retrospectively compared with the findings of surgical pathology (n=18) or more than 6 months of clinical follow-up (n=19). The sensitivity, specificity, and accuracy of US-guided core biopsy for the diagnosis of malignancy were 75.0%, 96.6%, and 91.9%, respectively. No immediate or delayed complications occurred.

Failure of radioiodine treatment in Graves' disease intentionally caused by a patient: suspected Munchausen syndrome.

We experienced a case with Graves' disease in which radioiodine treatment failed probably because of intentional spitting out of capsules of radioactive iodide. Chemical analysis of the substances collected from the trash in the treatment room demonstrated that its profile was the same as that of the capsules for radioiodine administration. Measurement of the iodine concentrations in a blood sample obtained at 24 h after the administration of radioiodine indicated that the patient showed iodine excess. These findings suggest that this may be a case of Munchausen syndrome.

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.

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 (Tc-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.

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

BACKGROUND: Oesophageal 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. METHODS: The 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 Rodnan's 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. RESULTS: The 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. > or =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). CONCLUSION: An 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.

Thallium-201 brain SPECT to diagnose aggressiveness of meningiomas.

This investigation was conducted to determine the ability of 201Tl brain SPECT with respect to preoperative prediction of lesional aggressiveness of meningioma. Fifty-nine lesions in 42 patients were examined. Early (15 min) and late (3 h) SPECT were obtained. Early uptake ratio (ER; lesion to normal brain average count ratio), late uptake ratio (LR) and the ratio of LR to ER (L/E ratio) were calculated. Twenty-three lesions exhibited malignant features based on histologic or clinical course such as recurrence or skull invasion. Both ER and LR of malignant meningiomas were significantly higher than those in thirty-six benign lesions. Benign lesions were classified into two groups for further analysis: meningotheliomatous type, which is the most common histology, and benign lesions other than the meningotheliomatous (other benign) type. ER in other benign type was lower than the meningotheliomatous and the malignant type. LR afforded differentiation of the malignant type from the two benign types. These two benign types could be distinguished on the basis of the L/E ratio. These results indicate that high pre-operative ER and LR values in patients with meningioma are indicators of the aggressiveness of lesions, i.e., malignant meningioma, recurrence or skull invasion.

Scintigraphic prediction of therapeutic outcomes of splenectomy in patients with thrombocytopenia.

UNLABELLED: In patients with thrombocytopenia, platelet scintigraphy has been used to locate the site of platelet sequestration and destruction and to determine whether splenectomy will be of benefit. However, its efficacy in predicting the outcome of splenectomy is controversial. We assessed the feasibility of platelet scintigraphy in this regard. METHODS: Platelet scintigraphy was performed in five patients (2 women, 3 men, mean age 48 years) before splenectomy. Four patients were diagnosed with idiopathic thrombocytopenic purpura and one with hypersplenism due to portal hypertension caused by intrahepatic chemotherapy against metastatic liver tumors of rectal cancer. Platelets labeled with 37 MBq of In-111 oxine or 1110 MBq of Tc-99m HMPAO were intravenously injected. Anterior images were obtained with a gamma camera 3-5 and 23-29 hours post-injection in five patients. Additional images were obtained 48 hours post-injection in three patients. For the analysis, a spleen/liver ratio (S/L ratio) was calculated using mean counts in regions of interest defined on the spleen and the liver. Serum platelet counts were measured before and after the operation; in three patients, splenectomy effectively resolved the thrombocytopenia (Group A), while it was ineffective in two patients (Group B). RESULTS: The S/L ratios were apparently higher in Group A than in Group B; in Group A, the ratios were 6.05, 6.97 and 3.16 at 3-5 hours, 12.67, 7.48 and 3.46 at 23-29 hours and 17.66 and 8.12 at 48 hours, whereas, in Group B, they were 0.67 and 0.66 at 3-5 hours, 0.52 and 0.54 at 24 hours, and 0.42 at 48 hours. CONCLUSION: The results of this study indicate that platelet scintigraphy is of value in predicting the therapeutic efficacy of splenectomy in patients with thrombocytopenia.

Differential diagnosis in patients with ring-like thallium-201 uptake in brain SPECT.

UNLABELLED: This study was performed to investigate lesions with ring-like thallium-201 (201Tl) uptake and to determine whether SPECT provides any information in differential diagnosis. METHODS: A total of 244 201Tl SPECT images were reviewed. In each study, early (15 min postinjection) and late (3 hr) brain SPECT images were obtained with 111 MBq of 201Tl. The early uptake ratio (ER; lesion to normal brain average count ratio) and the late uptake ratio (LR) and the L/E ratio (ratio of LR to ER) were calculated. RESULTS: Ring-like uptake was observed in pre-therapeutic 26 SPECT images, including ten glioblastoma multiformes (ER, 3.45 +/- 0.64; LR, 2.74 +/- 0.54; L/E ratio 0.80 +/- 0.13), five meningiomas (6.48 +/- 2.34; 4.41 +/- 1.41; 0.72 +/- 0.19), four metastatic lung cancers (3.47 +/- 1.23; 2.40 +/- 0.98; 0.70 +/- 0.14), four brain abscesses (2.48 +/- 1.06; 1.59 +/- 0.30; 0.78 +/- 0.15), one invasive lesion of squamous cell carcinoma from the ethmoid sinus (1.54; 1.52; 0.99), one medulloblastoma (3.53; 3.52; 1.00) and one hematoma (3.32; 2.36; 0.71). The ER of meningioma was significantly higher than those of glioblastoma multiforme (p < 0.0005), metastatic lung cancer (p < 0.005) and brain abscess (p < 0.0005). There were no significant differences among these three entities. The LR of meningioma was significantly higher than those of glioblastoma multiforme (p < 0.005), metastatic lung cancer (p < 0.005) and brain abscess (p < 0.0001). The LR of brain abscess was significantly lower than that of glioblastoma multiforme (p < 0.05). The L/E ratio could not differentiate these four entities. CONCLUSION: High ER and high LR in a lesion with ring-like uptake is likely an indicator of meningioma. The LR of brain abscess was significantly lower than that of glioblastoma multiforme, but 201T1 SPECT has still difficulty in differentiating abscess from brain tumor.