Lars Daniel Berthold

Magnetic Resonance Colonography and Virtual Magnetic Resonance Colonoscopy with the 1.0-t System: A Feasibility Study

Saar B, Heverhagen JT, Obst T, et al. Magnetic resonance colonography and virtual magnetic resonance colonoscopy with the 1.0-T system: A feasibility study. Invest Radiol 2000;35:521–526. RATIONALE AND OBJECTIVES.An ex vivo study and a clinical, prospective, patient study were undertaken to evaluate the feasibility of magnetic resonance (MR) colonography with a 1.0-T system. METHODS.An ex vivo colon model was scanned. A cleaned pig colon was prepared with six simulated sessile polyps (diameters of 4–12 mm) and one simulated pedunculated polyp (diameter of 5 mm). Subsequently, five patients (aged 39–81 years; four women, one man) were examined with MR colonography, immediately followed by endoscopic colonoscopy. After preparation for colonoscopy, the colon was filled with a Gd-DTPA/water solution (1:100). A breath-hold 3D gradient-echo sequence was acquired in both the prone and supine positions and after intravenous Gd-DTPA administration. Images were analyzed interactively by using multiplanar projections, maximum-intensity projection, and a virtual endoscopic view. The MR results were compared with the findings of the fiberoptic endoscopy. RESULTS.All seven simulated lesions of the colon model could be detected by MR imaging. In one patient, an advanced colon cancer as well as an additional small polyp was depicted. In the other four patients, single polyps with a diameter of 1 to 2.5 cm and a large adenoma were visualized by MR colonography. Contrast enhancement of the polyps was noted only after subtraction. CONCLUSIONS.The 1.0-T system is feasible for MR colonography. Reduced requirements for hardware could contribute to establish the novel technique as a screening method for colorectal polyps.

Association of homozygous LMNA mutation R471C with new phenotype: Mandibuloacral dysplasia, progeria, and rigid spine muscular dystrophy†

We report on a 7‐year‐old girl with a phenotype combining mandibuloacral dysplasia (MAD), progeria, and rigid spine muscular dystrophy. Mild proximal weakness, contractures, and rigidity of the spine were the primary findings. Although present since birth, dysmorphic manifestations typical for MAD and progeroid features became more prominent with time, and the full clinical phenotype was recognizable at early school age. Her phenotype was caused by a homozygous mutation in LMNA (c.1411C > T, which predicts p.R471C) inherited from the heterozygous, consanguineous, unaffected parents. This mutation has only been reported in compound heterozygous state and was associated with a milder phenotype. Some LMNA mutations are known to cause MAD and overlapping phenotypes (MAD spectrum) in an autosomal recessive pattern. The p.R471C homozygous LMNA mutation causes a severe phenotype of the MAD spectrum. This case extends the clinical spectrum of MAD and further expands the phenotypic range of lamin A/C associated diseases.

Measurement of torsion angles of long finger bones using computed tomography.

Abstract.Objective: Rotational dislocation at the fracture site is a complication of long finger bone fractures of the metacarpals and phalanges. To evaluate such deformities, we performed CT of the articular surfaces of these bones to demonstrate the torsion angles. Design: We evaluated 10 pairs of cadaver hands. These were placed flat, with the bones of interest perpendicular to the gantry to acquire axial images. The torsion of the long bone axes was defined as the angle between a tangent positioned parallel to the proximal articular surface and a tangent parallel to the distal articular surface of individual bones. Results: The maximum difference between repeated measurements was 4°. Intraobserver differences measured between right and left hands are less than 3°. Conclusion: Side differences in torsion angles exceeding 3° are strongly suspicious of a malrotation after fracture. These measurements might help to plan derotational osteotomy and assess the results of therapy.