Anomalous systemic arterial supply to normal basal segments of left lower lobe: characteristic imaging findings.

PURPOSE: The purpose of this study was to describe the characteristic findings in each imaging modality of anomalous systemic arterial supply to normal basal segments of the left lower lobe of the lung. METHOD: Five patients with anomalous systemic arterial supply to normal basal segments of the left lower lobe were retrospectively reviewed. Chest radiography, contrast-enhanced CT scan, angiography, and other imaging modalities were analyzed. RESULTS: The imaging findings of this anomaly were characterized by three issues as follows: an anomalous systemic artery arising from the thoracic aorta, absence of pulmonary arterial supply, and normal bronchial system as well as normal pulmonary parenchyma in the affected segments. The anomalous systemic artery was demonstrated on chest radiography, contrast-enhanced CT scan, MRI, and thoracic aortography. Absence of pulmonary arterial supply was revealed by pulmonary angiography, radiolabeled perfusion scan, and CT scan. Normal bronchial system was confirmed by radiolabeled ventilation scan, bronchography, and CT scan. CONCLUSION: CT is useful in making the correct diagnosis of this anomaly because it is the only diagnostic method that can demonstrate the anomalous systemic artery, absence of pulmonary arterial supply, and normal bronchial system in the affected segments.

Radiographic and CT appearances of the major fissures.

The major fissure is an important anatomic landmark in the interpretation of chest radiographs and computed tomographic (CT) scans. At radiography, the major fissures normally appear as hairlines of soft-tissue density; at conventional CT, they typically appear as lucent, hypovascular bands; and at high-resolution CT, they most often appear as sharp lines. The superolateral major fissure usually manifests as a curving edge at the upper lateral lung field with lateral opacity and medial lucency. The vertical fissure line appears as a fine, linear shadow, commencing in or near the costophrenic angle and coursing upward. The superomedial major fissure manifests as a short, obliquely oriented straight line. Progressive widening of the major fissure inferiorly manifests as a triangular area of increased opacity and represents intrafissural fat. Various inflammatory, granulomatous, neoplastic, and abnormal hemodynamic conditions involving the major fissure can affect its imaging appearance. Oblique orientation of the major fissure may complicate radiographic interpretation. The fissure may be incomplete or absent, complicating identification of various diseases. An incomplete major fissure may lead to disease spread, collateral air drift, or the "incomplete fissure sign," a sign that may, however, also be present in cases of complete fissure. Knowledge of the anatomy and normal variants of the major fissures is essential for recognizing their variable imaging appearances as well as related abnormalities.

Estimation of regional lung function in interstitial pulmonary disease using 99mTc-technegas and 99mTc-macroaggregated albumin single-photon emission tomography.

For quantitative evaluation of the regional lung function in patients with interstitial pulmonary disease (IP) in the sitting position, 99mTc-Technegas and 99mTc-macroaggregated albumin (MAA) single-photon emission tomography (SPET) studies were performed in 12 healthy controls (HC) and 42 IP patients. Four transverse images were prepared from the data obtained and designated as slices no. 1-4 from the top downward. Regions of interest (ROIs) were determined in the anterior and posterior parts of the lung in each slice, and the ratio of the count per voxel in the ROIs to the count in the entire lung was calculated as the regional Technegas index (T). The regional perfusion index (Q) was calculated by a similar procedure using the data of 99mTc-MAA SPET. The ratios between T and Q (T/Q) in the anterior and posterior regions of the lung, and the ratios of T and Q between the anterior and posterior regions of the lung (Tp/Ta and Qp/Qa) were examined. In the HC group, T/Q decreased but Tp/Ta and Qp/Qa increased from the upper to the lower lung fields. When IP patients were classified into (I) those in whom T/Q decreased from the upper to the lower lung fields, (II) those in whom it was similar in all slices, (III) those in whom it increased from slice 3 to slice 4, and (IV) those in whom it increased from slice 2 to slices 3 and 4, this classification was more closely correlated with %VC than with %DLCO or PaO2. When the patients were classified according to Tp/Ta and Qp/Qa into (A) those in whom the values were greater in the lower than the upper lung field, (B) those in whom the values were similar in all slices, and (C) those in whom the values were smaller in lower than in upper lung fields, categories B and C were observed frequently even in patients whose %VC was in the normal range. This method is considered to be an effective means to evaluate the progression and pathology of IP and to detect early impairment of lung function.

A case of hepatic hernia with echocardiographic findings simulating right atrial tumor.

A patient with hepatic hernia was found to have echocardiographic findings resembling a right atrial tumor. Magnetic resonance imaging was useful in establishing a definitive diagnosis of hepatic hernia. Hepatic hernias should be ruled out when a right atrial tumor is suspected on the basis of transthoracic echocardiographic findings.

[A case of adenoid cystic carcinoma presenting with stridor and which was treated by reversed gamma type stent placement].

A 66-year-old man was admitted to Saiseikai Suita Hospital with stridor and dyspnea. The flow-volume curve showed central airway obstruction pattern. Although a P-A chest roentogenogram was normal, chest tomogram demonstrated a tumor shadow in the lower portion of the trachea. Chest CT examination demonstrated a tumor arising from the posterior wall of the lower portion of the trachea and stenosis with wall thickening extending from the lower portion of the trachea to both main bronchi. Bronchofiberscopic examination revealed polypoid tumors obstructing the lower portion of the tracheal lumen, and biopsy was subsequently performed. On the night immediately after the bronchofiberscopic examination, the patent suddenly choked, and emergency intubation was performed. Adenoid cystic carcinoma was diagnosed on biopsy and we decided to place a spiral Z-stent. A reversed gamma-type stent placement was used. The first spiral Z-stent extended from the trachea to the right main bronchus and the second spiral Z-stent was placed in the left main bronchus through the first stent. Following the spiral Z-stent placement radiotherapy was performed. Spiral Z-stent placement resulted in dilation of the stenotic trachea and both main bronchi.

Management of malignant tracheobronchial stenosis with metal stents and Dumon stents.

BACKGROUND: Tracheobronchial stenosis caused by malignancy is a life- threatening problem. Stenting is one of the treatment modalities and recently has been used widely for the management of such stenosis, but we do not have a clear guide as to which stent should be selected. METHODS: We evaluated 25 patients (19 men, 6 women; mean age, 60.7 years; range, 34 to 77 years) received 24 metal stents (four covered with silicone rubber) and three Dumon stents. All 25 patients had severe dyspnea because of airway stenosis caused by malignant tumors. RESULTS: Among the 25 patients, airway obstruction due to extrinsic compression by tumor developed in 11 and was treated with a bare metal stent. The airway remained patent in 10 patients. In 16 patients with intraluminal tumor invasion, nine lesions were treated with a bare metal stent, four lesions with a covered metal stent, and the remaining three lesions with a Dumon stent. Recurrent stenosis did not occur in any patient with a covered metal stent or a Dumon stent. However, restenosis occurred in 4 patients with a bare metal stent, all of whom received laser therapy. In all patients, stenting immediately relieved dyspnea. Six patients lived for 32 days to 53 months after stenting, and 19 patients died of primary malignancies with a mean survival of 131.9 days. CONCLUSIONS: Metal stents are effective in treating malignant extrinsic tracheobronchial compression. The use of covered metal stents or Dumon stents is preferable for intraluminal stenosis due to malignant growth.

Acute aortic dissection with intramural hematoma: possibility of transition to classic dissection or aneurysm.

Acute aortic dissection with intramural hematoma has been believed to have a good prognosis, but we have encountered the transition of this entity to a classic dissection or aneurysm. We report the serial computed tomography (CT) features in 27 cases of acute aortic dissection with intramural hematoma. Eleven patients (40.7%) developed a classic dissection or aneurysm during follow-up. Four patients (14.8%) showed transition to a classic dissection without resolution of the intramural hematoma; each had a dilated ascending aorta measuring > 5 cm in diameter on the initial CT. One case (3.7%) developed an enlarging aneurysm without resolution of the intramural hematoma. In 19 cases (70.4%), the hematoma resolved; among these 19, the aortic diameter was significantly larger (p < 0.01) than those in a normal control group. Two of these 19 later developed an aneurysm, and four developed a classic dissection. This entity often (40.7%; 11 of 27) required surgical intervention or periodic follow-up CT examinations, particularly with a dilated ascending aorta of > 5 cm in diameter.

Incomplete interlobar fissures: bronchovascular analysis with CT.

Thin-section computed tomographic scans of both lungs in 154 patients, including seven cadavers, with lung cancer (n = 37), diffuse (n = 32) or inflammatory (n = 30) lung disease, other proved or suspected disease (n = 23), or healthy lungs (n = 32) were analyzed to determine the frequency of incomplete interlobar fissure (IIF). An IIF was defined as a discontinuous linear shadow that remained in contact with the chest wall. An IIF was found in 128 of 154 right lungs (83.1%) and 77 of 154 left lungs (50.0%). Some bronchovascular structures crossed or passed through two contiguous lobes in the fused area. The most common bronchovascular structure associated with an IIF was a pulmonary vein; this association was found in 87 right lungs (56.5%) and 20 left lungs (13.0%). An IIF was traversed by a pulmonary artery in only seven right lungs and 13 left lungs or by a bronchus in only three lungs. It is concluded that recognition of an IIF might improve understanding of the spread of pulmonary disease.

[Application of an expandable metallic Z-type stent for stenosis of the left main bronchus following tuberculosis--a case report].

A 32-year-old man had been suffering from dyspnea on exertion and stridor, which were due to stenosis of the left main bronchus as a complication of bronchial tuberculosis. A three-connection stent, 1.2 cm in diameter and 4.5 cm in length was placed at the site of the bronchial stenosis. Dyspnea disappeared 2 days after the procedure, and the pulmonary function 3 weeks later showed considerable improvements in %FVC, FEV1 and MMF.

Identification of pre- and postcentral gyri on CT and MR images on the basis of the medullary pattern of cerebral white matter.

The authors illustrate a new method to identify the pre- and postcentral gyri on computed tomographic (CT) and magnetic resonance (MR) images of the brain on the basis of the pattern of the medullary branches of the cerebral white matter. The most commonly used method to identify the gyri depends on recognition of the central sulcus by surface arrangement of the sulci. The two methods were compared by analysis of CT images of 104 subjects who had normal findings (age range, newborn to 60 years; 57 males and 47 females). The usefulness of the new method was also determined in angiographic studies of nine patients with space-occupying lesions. The method is especially helpful for identification of gyri on the lower level of the centrum semiovale and if space-occupying lesions are present that may result in a blurred depiction of sulci. Since MR imaging depicts the medullary branches more clearly than does CT, this new method should facilitate identification of the gyri with either modality.

[Aggressive natural killer cell lymphoproliferative disease of large granular lymphocytes with leukemia-like clinical course in the terminalstage].

A 20-year-old man was admitted to our clinic with fever elevation up to 39 degrees C for two months, generalized lymphadenopathy and hepatosplenomegaly. Histological examination of right scalene lymph node with HE staining showed T cell lymphoma-like finding. The patient was given vindesine and prednisolone, and there was almost no clinical improvement. Abnormal large granular lymphocyte appeared in peripheral blood and increased up to 17,000/microliters in the terminal stage of clinical course. These lymphocytes had abundant pale cytoplasm with rich large azurophilic granules and a large nucleus with a few nucleoli. The phenotype of these cells were as follows: Fc gamma R+, CD2+, CD5-, CD7-, CD3-, CD4-, CD1-, CD8-, sIg-, CD20-, CD11-, CD13-, OKIa+, CD25-, CD16+, Leu7-. These cells did not have the activity of antibody dependent cellular cytotoxicity but had natural killer activity. The gene of T cell receptor (beta and gamma chain) did not rearranged in these cells. We concluded that the abnormal cells were derived from natural killer cells, which caused aggressive clinical course.

MR and CT of tuberous sclerosis: linear abnormalities in the cerebral white matter.

A review of MR and CT images in five patients, 8 months to 22 years old, diagnosed as having tuberous sclerosis, revealed linear abnormalities in the cerebral white matter. A linear abnormality connecting a subependymal nodule to a subcortical lesion was shown in two patients as an area of hypointensity on T1-weighted MR images and as an area of hyperintensity on T2-weighted images. These appeared as faintly high-density areas on CT images. Seventeen linear abnormalities extending from the ventricle to the cortex with a subependymal nodule or subcortical lesion on each end were visible in all five patients as areas of hyperintensity on the T2-weighted images. On the T1-weighted images, only nine hypointense lines were noted. CT scans did not show these latter lines. Linear abnormalities in cerebral white matter are suggestive of lesions of demyelination, dysmyelination, hypomyelination, or lines of migration disorder. MR imaging, especially T2-weighted, is particularly sensitive in detecting these abnormalities.

[Evaluation of MRI for the staging of esophageal cancer].

The usefulness of MRI (magnetic resonance imaging) was evaluated in the diagnosis of the mediastinal invasion of esophageal cancer. MR examination was performed in 30 subjects without esophageal diseases and 23 patients with esophageal cancer. Normal esophagi and cancers were well visualized using T1-weighted image. In the axial section, every normal esophagus was contact to the aorta in the angle of less than 30 degree of the aortic circle. When the contact angle was less than 30 degrees, the stage of the cancer was below a1. When the angle was 30 degrees or greater, the stages were ranged from a0 to a3. In the oblique section orthogonal to the contact plain between the cancer and the aorta, the depth of the aortic invasion could be estimated. The sagittal scan was also helpful in the diagnosis of the invasion to trachea, left main bronchus and left atrium.

[Computed tomography for the diagnosis of thrombosed aortic dissection with extravasation].

Four cases of thrombosed aortic dissection with extravasation demonstrated by CT were presented. In CT diagnosis for this type of dissection, cautions should be employed not only in an inhomogenous density area in the mediastinum and pleural cavity but also in the presence of deviation of intimal calcification and relatively high density area of crescent shape in aortic wall on plain CT.

Improvement of T2-weighted images of central nervous system by motion artifact suppression technique (MAST).

Standard spin echo sequences of MRI with and without motion artifact suppression technique (MAST) were compared in 45 paired images of brain and 21 paired images of spine. The images were obtained on a Picker 1.5 T system with TR = 2 sec and TE = 100 or 120 msec. MAST is a method of refocusing transverse magnetization at echo time by modification of the gradient waveforms. Transverse, coronal, and sagittal planes of brain were compared in 10 paired images obtained from adults and five paired images from children. The spine was studied in sagittal images, 11 cervical images of adults, five lumbar images of adults, and five lumbar images of children. MAST was proven to be valuable not only for the detection of lesions but also for picturing anatomical details as in MR-cisternography and MR-myelography and the effects of iron ions. MAST improves significantly the quality of T2-weighted images, especially in children.

Left-right asymmetry of the temporal and parietal regions in children: based on the medullary pattern of cerebral white matter.

Lateralization of the posterior temporal lobe and inferior parietal lobule in childhood was studied on CT of 276 cases and compared with those in adulthood of 371 cases. CT images were analyzed based on the morphological features of medullary branches of the cerebral white matter. In children below 5 years of age, the left planum temporale was already more posteriorly located than the right in 56%, while the right was more so in 21%. The asymmetry of the middle temporal gyrus was similar to those of the planum temporale. The folding of the inferior parietal lobule was extensive and intricate on the left side in 63% and on the right side in 8% of children, almost identical to those in the adult. The visualization rates of the intraparietal sulcus were lower compared to those of the adult, but the higher visualization of the left side was a common tendency regardless of age. These alterations in left-right asymmetry seemed to be a morphologic substratum indicating the processes of localization of auditory function to those association areas.

Right upper lobe versus right middle lobe: differentiation with thin-section, high-resolution CT.

A new method was developed to differentiate the upper lobe from the middle lobe of the right lung with thin-section, high-resolution computed tomography. In the upper lobe, a medial subsegmental bronchus of an anterior segmental bronchus is always located lateral to the corresponding artery. In the middle lobe, a medial subsegmental bronchus of a lateral segmental bronchus and a superior and inferior subsegmental bronchus of a medial segmental bronchus are always located medial to the corresponding artery. In other words, the anatomic relationship between the subsegmental bronchi and the corresponding pulmonary arteries in the upper lobe is opposite to that in the middle lobe. One hundred seventeen cases, including 54 cases of lobar volume loss, were reviewed with this method, and in each case it was possible to differentiate the upper lobe from the middle lobe without the contiguous section analysis.

[Distribution of pulsed intra arterial infusion chemotherapy in hepatic carcinomas].

Evaluation of "Gianturco-Wallace chemotherapy pulser," which was developed to produce a more homogeneous drug distribution of the tumors in intra-arterial infusion chemotherapy, was assessed by comparative study of pulsed and nonpulsed arterial radionuclide infusion using Tc-99m pertechnetate for 18 cases of hepatic carcinomas (11 cases of hepatocellular carcinomas and 7 cases of metastatic hepatic carcinomas). Tc-99m pertechnetate, 740 MBq (20 mCi) diluted with saline (30 mL) was infused with or without pulse through the catheter into the hepatic artery at a rate of 1mL per minute. The intrahepatic dynamic radionuclide distribution was analyzed by the time activity curves of ROIs in the tumor and nontumor areas. Pulsed infusion interrupted laminar flow and produced more homogeneous radionuclide distribution in the liver, and combination of pulsed and nonpulsed infusion also produced better radionuclide distribution in the areas of the tumors. This method using Tc-99m pertechnetate was very useful as a simulation to determine the dynamic drug distribution of the tumor and non-tumor region in intraarterial infusion methods.