Mayumi Yasumoto

Relationship between bone marrow cellularity and apparent diffusion coefficient.

This study was performed to determine if there is a relationship between apparent diffusion coefficient (ADC) and cellularity of bone marrow of the posterior ilium. Four groups of various marrow cellularity underwent diffusion‐weighted echo‐planar imaging: 1) adults with normal hypocellularity (21 patients); 2) adults with normal normocellularity (13 patients); 3) young children with normal hypercellularity (5 patients); and 4) adults with lymphoma‐related hypercellularity (3 patients). In all adults, marrow cellularity was confirmed by uni‐or bilateral bone marrow biopsies. In children, the iliac marrow was presumed hypercellular because of their ages. A total of 66 ADC values of bone marrow calculated from diffusion‐weighted images with b‐values of 30 and 300 seconds/mm2 was evaluated. Hypercellular marrow (normal and lymphoma‐related) showed the highest mean ADC, and hypocellular the lowest ADC. Statistically significant differences were found between three groups of normal marrow: hypocellular, normocellular, and hypercellular. There is a positive correlation between ADC and cellularity of bone marrow. J. Magn. Reson. Imaging 2001;13:757–760.

The relation between an esophageal cancer and associated cancers in adjacent organs

Background. The relation between esophageal cancers and head and neck tumors was studied in order to improve the treatment results in patients with multiple cancers.

MRI of ranulas

Abstract We reviewed the MRI of 20 patients with a ranula (8 simple and 12 plunging) and ten with other cystic masses in the floor of the mouth and/ or suprahyoid portion of the neck (three haemangiomas, two neuromas, one monomorphic adenoma, one lipoma, two lateral cervical cysts and one dermoid cyst). Histological diagnoses were obtained in all cases with the exception of one presumed haemangioma. Ranulas were all well-defined, homogeneous masses giving low signal on T1-and markedly high signal on T2-weighted images. While simple ranulas were all confined to the sublingual space, plunging ranulas were centered on the submandibular space and tended to spill into one or more adjacent spaces. They extended into the sublingual space anteriorly (producung a so-called tail sign) in eight of 12 cases and into the parapharyngeal space superiorly in five. Although they sometimes filled a considerable part of the parapharyngeal space, displacement of surrounding muscles or vessels was usually slight, which was thought to reflect the nature of extravasation pseudocysts. All other cystic masses in our study had one or more MRI finding different from those of ranulas and could be easily differentiated from them.

Primary malignant lymphoma of the maxillary sinus: CT and MRI

Abstract We reviewed the CT and MRI of seven patients with primary malignant lymphoma of the maxillary sinus to find if there are characteristic imaging findings suggestive of the disease. The images were analysed for appearance, size, signal, internal characteristics, extent of tumour, bone change and lymph node enlargement. In two patients, the tumour first presented with mucosal thickening. In the remaining five, the tumours were an expansile mass 4–6 cm in diameter at the time of detection. Although it was difficult to distinguish tumour from mucosa or obstructed fluid on CT, T2-weighted MRI enabled us to separate tumour from normal mucosa or fluid. In two patients, the tumours were heterogeneous. Calcification and haemorrhage were observed in one patient. Periantral soft-tissue infiltration was always present, even when tumour appeared as slight mucosal thickening. Posterior extension was seen in all patients. Permeative and lytic bone destruction accompanied most cases of periantral soft-tissue infiltration; mixed destruction and sclerosis was also observed. Mucosal thickening with periantral soft-tissue infiltration may suggest malignant lymphoma of the maxillary sinus in its early form. Various types of bone change may accompany the periantral soft-tissue infiltration.

Recurrent pleomorphic adenoma of the head and neck

Abstract We reviewed the clinical and imaging files of 15 patients with pathologically confirmed recurrent pleomorphic adenomas of the head and neck. The primary tumours were in the lacrimal gland (1 case), cheek (2), palate (5), parotid gland (4), and submandibular gland (3). Recurrence was generally late, with an average of 14.9 years between initial surgery and recurrence. Multiple recurrent tumours, measuring 5–50 mm were found in eight patients. In all palatal cases recurrence was large and solitary. Most recurrent pleomorphic adenomas were well delineated with smooth margins, like most primary tumours. Irregularity of the margins was seen in four patients. In four of the five tumours of the palate and in the orbital lesion, the recurrent tumours caused bone destruction, thus mimicking malignant lesions. Irregular-margined recurrences seem to be rather small and found among multiple recurrent nodules.

CT Features in Second Cancers of the Maxillary Sinus

Five patients with a second maxillary cancer (squamous cell carcinoma), which developed 6 to 17 years after initial treatment for the first cancer on the opposite side, were compared with 21 control cases with a primary cancer on the basis of computed tomography (CT) findings. Generally, the second cancer was found at an earlier stage. The specific CT findings of early sinus carcinoma were uneven soft tissue distribution in the antrum and tumor permeation with bone fragments remaining at the original tumor site. These findings may be helpful for distinguishing this cancer from benign chronic sinusitis and/or other malignant sinus disease. The pterygoid process, medial bony wall, and ethmoid sinus had a tendency to be spared in most of the 5 patients with second maxillary cancer compared to the 21 control cases.

MR findings of ruptured endometrial cyst: Comparison with tubo-ovarian abscess

OBJECTIVE To evaluate the MR findings of ruptured endometrial cyst, focusing on the differentiation from tubo-ovarian abscess (TOA). PATIENTS AND METHODS We reviewed the records of 21 patients who underwent preoperative MR examinations for TOAs (n=15) or ruptured endometrial cysts (n=6). We evaluated the presence of hyper-intense ascites and hyper-intense peritoneum in T1-weighted sequences, strong enhancement of the peritoneum, hyper-intense content and hyper-intense rim of the ovarian lesion in T1-weighted sequences, and strong wall enhancement of the ovarian lesion. χ2 test was used to assess the relationship between TOA cases versus cases with ruptured endometrial cysts, and the three MR peritoneal findings. We evaluated the relationship between TOA versus non-infected endometrial cysts, and the ovarian MR peritoneal findings, too. RESULTS Hyper-intense ascites was found in all of the patients with ruptured endometrial cyst and none with TOA (p<0.0001). Hyper-intense peritoneum was observed in only TOAs cases (4 of 8). Strong peritoneal enhancement was seen in 3 of the 3 patients with ruptured endometrial cyst and 7 of the 13 patients with TOA (p=0.1366). Hyper-intense content of the ovarian lesion was seen more often in the non-infected endometrial cysts than in the TOAs (p=0.001607), while hyper-intense rim was more frequent in TOAs (p=0.000402). Strong wall enhancement was observed only in TOAs (11 of 15) (p=0.001355). CONCLUSIONS MR images are useful to differentiate ruptured endometrial cyst from TOA.

Recurrent Pleomorphic Adenoma of the Head and Neck: Imaging Findings

We reviewed the clinical and imaging files of 15 pathologically confirmed recurrent pleomorphic adenomas of the head and neck. Recurrence was generally late with an average interval between the initial surgery and recurrences of 14.9 years. Multiple recurrent tumors were found in eight of the 15 patients with tumor size 5 to 50 mm. In all palatal cases recurrence was solitary. Most recurrent tumors were well delineated with smooth margins. Margin irregularity was seen in four of the 15 patients. In four of the five palate cases and in the orbital case, recurrent tumors caused bone destruction. Some recurrent tumors may mimic malignant lesions based on bone destruction or margin irregularity. Recurrent pleomorphic adenomas in the palate may tend to develop a large solitary mass with bone destruction. Irregular-margined recurrences are rather small among multiple recurrent nodules.