Rashid Hashmi

Peripheral Nerve Intraneural Ganglion Cyst: Mr Findings in Three Cases

We present MR findings of three cases of surgically proved intraneural ganglion cysts involving the common peroneal nerve (two patients) and ulnar nerve (one patient). The lesions were located along the course of the involved nerve and situated close to a joint. MRI demonstrated the cystic nature and extent of the lesions with clear definition of the anatomic relationship of the lesions to the surrounding structures.

Traction injuries of the brachial plexus : Signal intensity changes of the posterior cervical paraspinal muscles on MRI

PURPOSE Our goal was to evaluate MR signal intensity change of the posterior cervical paraspinal muscles in brachial plexus traction injuries to determine the value of this finding in the diagnosis of nerve root avulsion. METHOD MR images of 11 consecutive patients, 7 with nerve root avulsion and 4 without nerve root avulsion, were retrospectively analyzed, focusing on the signal intensity of the paraspinal muscles. RESULTS Among the seven patients with nerve root avulsion, T2- or T2*-weighted MR images showed increased signal intensity in the deep posterior paraspinal muscles in five and traumatic meningocele in four. The signal intensity of the posterior paraspinal muscles was normal in all patients without nerve root injuries. CONCLUSION MR signal intensity change in the deep posterior cervical paraspinal muscles is related to denervation and suggests the presence of nerve root avulsion.

MR assessment of meniscal movement during knee flexion: correlation with the severity of cartilage abnormality in the femorotibial joint.

Purpose The purpose of this study was to assess the degree of meniscal movement during knee flexion on MR images and to correlate it with the severity of cartilage damage in the femorotibial joint. Method Sagittal MR images were obtained at extension and 45° of flexion in 35 knees. A shortening ratio in the distance between the anterior and posterior horns at 0–45° of knee flexion was calculated in each meniscus and was correlated with the degree of cartilage abnormality in the femorotibial joint. Results The shortening ratio of the meniscus was reduced in knees with cartilage abnormality in the femorotibial joint. The shortening ratio of the medial meniscus was inversely correlated with the degree of cartilage abnormality in the medial femoral condyle and with that in the medial tibial plateau. Conclusion Restricted shortening ratio of the meniscus may be related to cartilage damage in the femorotibial joint.

Subchondral insufficiency fracture of the femoral head: Magnetic Resonance Imaging findings correlated with micro-computed tomography and histopathology

We described magnetic resonance (MR) imaging findings of subchondral insufficiency fracture of the femoral head without collapse in which micro-computed tomography (CT) and histopathologic studies were performed. Magnetic resonance imaging showed a subchondral low-signal intensity band, which corresponded to the fracture callus. Diffuse bone marrow edema with contrast enhancement effect was seen in both the proximal and distal segments of the low-signal intensity band. These features are distinct from those of avascular necrosis.

Regional Ventilation-Perfusion Mismatch in Interstitial Pneumonia Correlation Between Scintigraphy and CT

Interstitial pneumonia is one of the many causes of a scintigraphic ventilation-perfusion (V/Q) mismatch. To evaluate the morphologic features of V/Q mismatched areas in patients with interstitial pneumonia, we correlated the findings on lung scintigraphy using Kr-81m and Tc-99m MAA with CT scan findings. Of 41 patients, 20 (49%) had a high V/Q mismatched areas. All of these areas corresponded to cystic air spaces shown on CT, and most of the showed a honeycomb pattern. Ventilation-perfusion matched defects were seen in 23 patients (56%). The matched defects corresponded to cystic air spaces (honeycomb or bullous changes) or lung attenuation changes of varying degrees on CT. Cystic air spaces with high V/Q mismatch are considered to be normally ventilated. To distinguish mismatched areas of interstitial pneumonia from areas of pulmonary embolism, it may be necessary to compare scintigraphic findings with CT.

Interpretation of normal anatomic structures on chest radiography: Comparison of Fuji Computed Radiography (FCR) 5501D with FCR 5000 and screen-film system

The purpose of this study was to investigate the usefulness of Fuji Computed Radiography (FCR) 5501D by comparing it with FCR 5000 and a screen‐film system (S/F). Posteroanterior chest radiographs often patients with no abnormality on chest CT scans were obtained with FCR 5501D, FCR 5000, and S/F. Six observers (three radiologists and three radio‐technologists) evaluated the visibility of nine normal anatomic structures (including lungs, soft tissue, and bones) and overall visibility on each image. Observers scored using a five‐point scale on each structure. FCR 5000 showed a significantly higher score in soft tissue and bone structures, and overall visibility compared with S/F, but, there was no significant difference between them in the visibility of all four normal lung structures. Compared with S/F, the score for FCR 5501D was higher in eight of the nine normal structures, including three of the four lung structures (unobscured lung, retrocardiac lung, and subdiaphragmatic lung), and overall visibility. Compared with FCR 5000, the score for FCR 5501D was higher in three normal structures, including two of the four lung structures (unobscured lung and subdiaphragmatic lung), and overall visibility. FCR 5501D was the best among the three techniques to visualize normal anatomic structures, particularly the obscured and unobscured lung.

Central scar in hepatic focal nodular hyperplasia revealed by scintigraphy.

The authors report a case of focal nodular hyperplasia that showed normal uptake of hepatocyte-specific ligand, Tc-99m galactosyl human serum albumin, and increased radiocolloid uptake. A focal photopenic area in the lesion was shown on SPECT images on both studies. Pathological evaluation of the su

Increased uptake of 99Tcm-ethyl cysteinate dimer in patients with brain tumours.

We performed 229 99Tcm-ethyl cysteinate dimer (ECD) single photon emission tomography (SPET) studies in 185 patients with brain tumour. Increased uptake of the tracer was observed in 11 cases. In six of these 11 patients, focal intense activity was seen in the area surrounding the tumour. Five of these six patients had episodes of seizure, and ictal SPET showed further increased uptake in the area of hyperperfusion in one patient. Hyperperfusion surrounding the tumour might be related to seizure. In the remaining five patients, increased accumulation was seen in the tumour. Three of these five patients had a discrepancy between 99Tcm-ECD SPET and 201Tl SPET imaging. There could be some difference in the mechanism of accumulation in the tumour between 99Tcm-ECD and 201Tl.